Version bump

Fix unused compiler warning when not VL_THREADED.
Commentary: Changes update
2026-10-05 17:43:31 +02:00 · 2022-10-01 08:28:27 -04:00 · 2022-09-30 23:41:35 -04:00 · 2022-09-30 23:03:26 -04:00 · 2022-09-28 19:11:00 -04:00 · 2022-09-28 14:43:40 +01:00
1204 changed files with 67246 additions and 51831 deletions
@@ -17,7 +17,7 @@ AllowShortLoopsOnASingleLine: true
 AlwaysBreakAfterDefinitionReturnType: None
 AlwaysBreakAfterReturnType: None
 AlwaysBreakBeforeMultilineStrings: false
-AlwaysBreakTemplateDeclarations: false
+AlwaysBreakTemplateDeclarations: true
 BinPackArguments: true
 BinPackParameters: true
 BraceWrapping:
@@ -59,15 +59,27 @@ ForEachMacros:
  - foreach
  - Q_FOREACH
  - BOOST_FOREACH
-IncludeBlocks:   Preserve
+
+# Include grouping/sorting
+SortIncludes:    true
+IncludeBlocks:   Regroup
 IncludeCategories:
-  - Regex:           '^"(llvm|llvm-c|clang|clang-c)/'
-    Priority:        2
-  - Regex:           '^(<|"(gtest|gmock|isl|json)/)'
-    Priority:        3
-  - Regex:           '.*'
-    Priority:        1
-IncludeIsMainRegex: '(Test)?$'
+  - Regex:           '"(config_build|verilated_config|verilatedos)\.h"'
+    Priority:        -1 # Sepecials before main header
+  - Regex:           '(<|")verilated.*'
+    Priority:        1 # Runtime headers
+  - Regex:           '"V3.*__gen.*\.h"'
+    Priority:        3 # Generated internal headers separately
+  - Regex:           '"V3.*"'
+    Priority:        2 # Internal header
+  - Regex:           '".*"'
+    Priority:        4 # Other non-system headers
+  - Regex:           '<[[:alnum:]_.]+>'
+    Priority:        5 # Simple system headers next
+  - Regex:           '<.*>'
+    Priority:        6 # Other system headers next
+IncludeIsMainRegex: '$'
+
 IndentCaseLabels: false
 IndentPPDirectives: None
 IndentWidth:     4
@@ -91,7 +103,6 @@ PenaltyExcessCharacter: 1000000
 PenaltyReturnTypeOnItsOwnLine: 60
 PointerAlignment: Left
 ReflowComments:  true
-SortIncludes:    false
 SortUsingDeclarations: true
 SpaceAfterCStyleCast: false
 SpaceAfterTemplateKeyword: true
@@ -29,7 +29,7 @@ jobs:
    strategy:
      fail-fast: false
      matrix:
-        os: [ubuntu-20.04, ubuntu-18.04]
+        os: [ubuntu-22.04, ubuntu-20.04, ubuntu-18.04]
        compiler:
          - { cc: clang, cxx: clang++ }
          - { cc: gcc,   cxx: g++     }
@@ -37,9 +37,16 @@ jobs:
        exclude:
          # Build pull requests only with ubuntu-20.04 and without m32
          - os:  ${{ github.event_name == 'pull_request' && 'ubuntu-18.04' || 'do-not-exclude' }}
+          - os:  ${{ github.event_name == 'pull_request' && 'ubuntu-22.04' || 'do-not-exclude' }}
          - m32: ${{ github.event_name == 'pull_request' && 1              || 'do-not-exclude' }}
          # Build -m32 only on ubuntu-20.04
          - {os: ubuntu-18.04, m32: 1}
+          - {os: ubuntu-22.04, m32: 1}
+        include:
+          # Build GCC 10 on ubuntu-20.04
+          - os: ubuntu-20.04
+            compiler: { cc: gcc-10, cxx: g++-10 }
+            m32: 0
    runs-on: ${{ matrix.os }}
    name: Build | ${{ matrix.os }} | ${{ matrix.compiler.cc }} ${{ matrix.m32 && '| -m32' || '' }}
    env:
@@ -90,7 +97,7 @@ jobs:
    strategy:
      fail-fast: false
      matrix:
-        os: [ubuntu-20.04, ubuntu-18.04]
+        os: [ubuntu-22.04, ubuntu-20.04, ubuntu-18.04]
        compiler:
          - { cc: clang, cxx: clang++ }
          - { cc: gcc,   cxx: g++     }
@@ -99,9 +106,18 @@ jobs:
        exclude:
          # Build pull requests only with ubuntu-20.04 and without m32
          - os:  ${{ github.event_name == 'pull_request' && 'ubuntu-18.04' || 'do-not-exclude' }}
+          - os:  ${{ github.event_name == 'pull_request' && 'ubuntu-22.04' || 'do-not-exclude' }}
          - m32: ${{ github.event_name == 'pull_request' && 1              || 'do-not-exclude' }}
          # Build -m32 only on ubuntu-20.04
          - {os: ubuntu-18.04, m32: 1}
+          - {os: ubuntu-22.04, m32: 1}
+        include:
+          # Test with GCC 10 on ubuntu-20.04 without m32
+          - {os: ubuntu-20.04, compiler: { cc: gcc-10, cxx: g++-10 }, m32: 0, suite: dist-vlt-0}
+          - {os: ubuntu-20.04, compiler: { cc: gcc-10, cxx: g++-10 }, m32: 0, suite: dist-vlt-1}
+          - {os: ubuntu-20.04, compiler: { cc: gcc-10, cxx: g++-10 }, m32: 0, suite: dist-vlt-2}
+          - {os: ubuntu-20.04, compiler: { cc: gcc-10, cxx: g++-10 }, m32: 0, suite: vltmt-0}
+          - {os: ubuntu-20.04, compiler: { cc: gcc-10, cxx: g++-10 }, m32: 0, suite: vltmt-1}
    runs-on: ${{ matrix.os }}
    name: Test | ${{ matrix.os }} | ${{ matrix.compiler.cc }} | ${{ matrix.suite }} ${{ matrix.m32 && '| -m32' || '' }}
    env:
@@ -110,7 +126,7 @@ jobs:
      CI_M32: ${{ matrix.m32 }}
      CC: ${{ matrix.compiler.cc }}
      CXX: ${{ matrix.compiler.cxx }}
-      CACHE_BASE_KEY: test-${{ matrix.os }}-${{ matrix.compiler.cc }}-m32=${{ matrix.m32 }}-${ matrix.suite }}
+      CACHE_BASE_KEY: test-${{ matrix.os }}-${{ matrix.compiler.cc }}-m32=${{ matrix.m32 }}-${{ matrix.suite }}
      CCACHE_MAXSIZE: 64M # Per build matrix entry (2160M in total)
      VERILATOR_ARCHIVE: verilator-${{ github.sha }}-${{ matrix.os }}-${{ matrix.compiler.cc }}${{ matrix.m32 && '-m32' || '' }}.tar.gz
    steps:
@@ -11,7 +11,7 @@ on:
 jobs:
  Test:
    name: "'docs/CONTRIBUTORS' was signed"
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-22.04
    steps:
    - uses: actions/checkout@v2
    - run: test_regress/t/t_dist_contributors.pl
@@ -10,11 +10,11 @@ on:

 jobs:
  format:
-    runs-on: ubuntu-20.04
-    name: Ubuntu 20.04 | format
+    runs-on: ubuntu-22.04
+    name: Ubuntu 22.04 | format
    env:
      CI_OS_NAME: linux
-      CI_RUNS_ON: ubuntu-20.04
+      CI_RUNS_ON: ubuntu-22.04
      CI_COMMIT: ${{ github.sha }}
      CI_M32: 0
    steps:
@@ -27,14 +27,14 @@ jobs:
          CI_BUILD_STAGE_NAME: build
        run: |
          bash ci/ci-install.bash &&
-          sudo apt-get install clang-format-11 yapf3 &&
+          sudo apt-get install clang-format-14 yapf3 &&
          git config --global user.email "[email protected]" &&
          git config --global user.name "github action"
      - name: Format code
        run: |
          autoconf &&
          ./configure &&
-          make -j 2 format CLANGFORMAT=clang-format-11 &&
+          make -j 2 format CLANGFORMAT=clang-format-14 &&
          git status
      - name: Push
        run: |
@@ -1,5 +1,6 @@
 \#*
 .#*
+.gdb_history
 .nfs*
 *~
 *.tidy
@@ -8,6 +8,147 @@ The changes in each Verilator version are described below.  The
 contributors that suggested a given feature are shown in []. Thanks!


+Verilator 4.228 2022-10-01
+==========================
+
+**Announcement:**
+
+* The next release is anticipated primere Verilator Version 5.  Please
+  consider beta-testing the github 'develop-v5' branch, which will soon
+  merge into the github 'master' branch (#3383).
+
+**Minor:**
+
+* Support some IEEE signal strengths (#3601) (#3629). [Ryszard Rozak/Antmicro]
+* Add --main to generate main() C++ (previously was experimental only).
+* Add --build-jobs, and rework arguments for -j (#3623). [Kamil Rakoczy]
+* Rename --bin to --build-dep-bin.
+* Rename debug flags --dumpi-tree, --dumpi-graph, etc. [Geza Lore]
+* Fix thread saftey in SystemC VL_ASSIGN_SBW/WSB (#3494) (#3513). [Mladen Slijepcevic]
+* Fix crash in gate optimization of circular logic (#3543). [Bill Flynn]
+* Fix arguments in non-static method call (#3547) (#3582). [Gustav Svensk]
+* Fix default --mod-prefix when --prefix is repeated (#3603). [Geza Lore]
+* Fix calling trace() after open() segfault (#3610) (#3627). [Yu-Sheng Lin]
+* Fix typedef'ed class conversion to boolean (#3616). [Aleksander Kiryk]
+* Fix Verilation speed when disabled warnings (#3632). [Kamil Rakoczy/Antmicro]
+
+
+Verilator 4.226 2022-08-31
+==========================
+
+**Minor:**
+
+* Add --future0 and --future1 options.
+* Support class parameters (#2231) (#3541). [Arkadiusz Kozdra/Antmicro]
+* Support wildcard index associative arrays (#3501). [Arkadiusz Kozdra/Antmicro]
+* Support negated properties (#3572). [Aleksander Kiryk]
+* Support $test$plusargs(expr) (#3489).
+* Rename trace rolloverSize() (#3570).
+* Improve Verilation speed with --threads on large designs. [Geza Lore]
+* Improve Verilation memory by reducing V3Number (#3521). [Mariusz Glebocki/Antmicro]
+* Fix struct pattern assignment (#2328) (#3517). [Mostafa Gamal]
+* Fix public combo propagation issues (#2905). [Todd Strader]
+* Fix incorrect tristate logic (#3399) [shareefj, Vighnesh Iyer]
+* Fix incorrect bit op tree optimization (#3470). [algrobman]
+* Fix bisonpre for MSYS2 (#3471).
+* Fix max memory usage (#3483). [Kamil Rakoczy/Antmicro]
+* Fix empty string arguments to display (#3484). [Grulfen]
+* Fix table misoptimizing away display (#3488). [Stefan Post]
+* Fix unique_ptr memory header for MinGW64 (#3493).
+* Fix $dump systemtask with --output-split-cfuncs (#3495) (#3497). [Varun Koyyalagunta]
+* Fix wrong bit op tree optimization (#3509). [Nathan Graybeal]
+* Fix nested default assignment for struct pattern (#3511) (#3524). [Mostafa Gamal]
+* Fix sformat string incorrectly cleared (#3515) (#3519). [Gustav Svensk]
+* Fix segfault exporting non-existant package (#3535).
+* Fix void-cast queue pop_front or pop_back (#3542) (#3364). [Drew Ranck]
+* Fix case statement comparing string literal (#3544). [Gustav Svensk]
+* Fix === with some tristate constants (#3551). [Ryszard Rozak/Antmicro]
+* Fix converting subclasses to string (#3552). [Arkadiusz Kozdra/Antmicro]
+* Fix --hierarchical with order-based pin connections (#3583) (#3585). [Kelin9298]
+
+
+Verilator 4.224 2022-06-19
+==========================
+
+**Major:**
+
+* VCD tracing is now parallelized with --threads (#3449). [Geza Lore, Shunyao CAD]
+
+**Minor:**
+
+* Add -f<optimization> options to replace -O<letter> options (#3436).
+* Changed --no-merge-const-pool to -fno-merge-const-pool (#3436).
+* Changed --no-decoration to remove output whitespace (#3460). [Kamil Rakoczy]
+* Support compile time trace signal selection with tracing_on/off (#3323). [Shunyao CAD]
+* Support non-ANSI interface port declarations (#3439). [Geza Lore, Shunyao CAD]
+* Support concat assignment to packed array (#3446).
+* Improve conditional merging optimization (#3125). [Geza Lore, Shunyao CAD]
+* Define VM_TRACE_VCD when tracing in VCD format. [Geza Lore, Shunyao CAD]
+* Add assert when VerilatedContext is mis-deleted (#3121). [Rupert Swarbrick]
+* Internal prep work towards timing control. [Krzysztof Bieganski/Antmicro]
+* Fix hang with large case statement optimization (#3405). [Mike Urbach]
+* Fix UNOPTFLAT warning from initial static var (#3406). [Kamil Rakoczy]
+* Fix compile error when enable VL_LEAK_CHECKS (#3411). [HungMingWu]
+* Fix cmake rules to support higher-level targets (#3377) (#3386). [Martin Stadler]
+* Fix BLKANDNBLK on $readmem/$writemem (#3379). [Alex Solomatnikov]
+* Fix 'with' operator with type casting (#3387). [xiak95]
+* Fix incorrect conditional merging (#3409). [Raynard Qiao]
+* Fix passing VL_TRACE_FST_WRITER_THREAD in CMake build. [Geza Lore, Shunyao CAD]
+* Fix compile error under strict C++11 mode (#3463). [Kevin Kiningham]
+* Fix public unpacked input ports (#3465). [Todd Strader]
+
+
+Verilator 4.222 2022-05-02
+==========================
+
+**Minor:**
+
+* Split --prof-threads into --prof-exec and --prof-pgo (#3365). [Geza Lore, Shunyao CAD]
+* Deprecate 'vluint64_t' and similar types (#3255).
+* Raise error on assignment to const in initial blocks. [Geza Lore, Shunyao CAD]
+* Issue INITIALDLY/COMBDLY/BLKSEQ warnings consistent with Verilator execution. [Geza Lore, Shunyao CAD]
+* Support LoongArch ISA multithreading (#3353) (#3354). [Xi Zhang]
+* Fix MSVC localtime_s (#3124).
+* Fix Bison 3.8.2 error (#3366). [elike-ypq]
+* Fix rare bug in -Oz (V3Localize) (#3286). [Geza Lore, Shunyao CAD]
+* Fix tracing interfaces inside interfaces (#3309). [Kevin Millis]
+* Fix filenames with dots overwriting debug .vpp files (#3373).
+* Fix including VK_USER_OBJS in make library (#3370) (#3382). [Julien Margetts]
+* Fix hang in generate symbol references (#3391) (#3398). [Yoda Lee]
+* Fix missing #include <memory> (#3392). [Aliaksei Chapyzhenka]
+* Fix crash in recursive module inlining (#3393). [david-sawatzke]
+* Fix --protect-ids mangling names of library methods. [Geza Lore, Shunyao CAD]
+* Fix foreach segmentation fault (#3400). [Kamil Rakoczy]
+
+
+Verilator 4.220 2022-03-12
+==========================
+
+**Minor:**
+
+* Removed the deprecated lint_off flag -msg; use -rule instead.
+* Removed the deprecated "fl" attribute in XML output; use "loc" attribute instead.
+* Suppress WIDTH warning on negate using carry bit (#3295). [Peter Monsson]
+* Add trace dumpvars() call for selective runtime tracing (#3322). [Shunyao CAD]
+* Add VERILATOR_VERSION_INTEGER for determining API (#3343). [Larry Doolittle]
+* Improve various V3Combine algorithm details (#3328). [Yutetsu TAKATSUKASA]
+* Improve various V3Order algorithm details. [Geza Lore]
+* Fix MacOS arm64 build (#3285) (#3291). [Guokai Chen]
+* Fix signed number operation (#3294) (#3308). [Raynard Qiao]
+* Fix FST traces to include vector range (#3296) (#3297). [Jamie Iles]
+* Fix skipping public enum values with four-state values (#3303).
+* Fix $readmem file not found to be warning not error (#3310). [Alexander Grobman]
+* Fix class stringification on wide arrays (#3312). [Iru Cai]
+* Fix $fscanf etc to return -1 on EOF (#3313). [Jose Tejada]
+* Fix public function arguments that are arrayed (#3316). [pawel256]
+* Fix unnamedblk error on foreach (#3321). [Aliaksei Chapyzhenka]
+* Fix crash in recursive module inlining (#3324). [Larry Doolittle]
+* Fix VL_RESTORER behavior on passing a lvalue reference (#3326). [HungMingWu]
+* Fix compile error with --trace-fst --sc (#3332). [leavinel]
+* Fix cast to array types (#3333). [Todd Strader]
+* Fix Vdeeptemp error with --threads and --compiler clang (#3338). [Per Karlsson]
+
+
 Verilator 4.218 2022-01-17
 ==========================

@@ -57,7 +198,7 @@ Verilator 4.216 2021-12-05
 **Minor:**

 * Internal code cleanups and improvements. [Geza Lore]
-* Improve --thread verilation-time performance.
+* Improve --thread Verilation-time performance.
 * Support task name in $display %m (#3211). [Julie Schwartz]
 * Make 'bit', 'logic' and 'time' types unsigned by default. [Geza Lore]
 * Optimize $random concatenates/selects (#3114).
@@ -81,7 +222,7 @@ Verilator 4.214 2021-10-17

 **Major:**

-* Add profile-guided optmization of mtasks (#3150).
+* Add profile-guided optimization of mtasks (#3150).

 **Minor:**

@@ -111,7 +252,7 @@ Verilator 4.212 2021-09-01
 * Fix re-evaluation of logic dependent on state set in DPI exports (#3091). [Geza Lore]
 * Support unpacked array localparams in tasks/functions (#3078). [Geza Lore]
 * Support timeunit/timeprecision in $unit.
-* Support assignment patterns as children of pins (#3041). [Krzysztof Bieganski]
+* Support assignment patterns as children of pins (#3041). [Krzysztof Bieganski/Antmicro]
 * Add --instr-count-dpi to tune assumed DPI import cost for multithreaded
  model scheduling. Default value changed to 200 (#3068). [Yinan Xu]
 * Output files are split based on the set of headers required
@@ -147,7 +288,7 @@ Verilator 4.210 2021-07-07

 * Add --prof-c to pass profiling to compiler (#3059). [Alexander Grobman]
 * Optimize a lot more model variables into function locals (#3027). [Geza Lore]
-* Support middle-of-design nested topmodules (#3026). [Dan Petrisko]
+* Support middle-of-design nested top modules (#3026). [Dan Petrisko]
 * Remove deprecated --no-relative-cfuncs option (#3024). [Geza Lore]
 * Remove deprecated --inhibit-sim option (#3035). [Geza Lore]
 * Merge const static data globally into a new constant pool (#3013). [Geza Lore]
@@ -176,7 +317,7 @@ Verilator 4.204 2021-06-12
 * Prep work towards better ccache hashing/performance. [Geza Lore]
 * Fix assertion failure in bitOpTree optimization (#2891) (#2899). [Raynard Qiao]
 * Fix DPI functions not seen as vpiModule (#2893). [Todd Strader]
-* Fix bounds check in VL_SEL_IWII (#2910). [Krzysztof Bieganski]
+* Fix bounds check in VL_SEL_IWII (#2910). [Krzysztof Bieganski/Antmicro]
 * Fix slowdown in elaboration (#2911). [Nathan Graybeal]
 * Fix initialization of assoc in assoc array (#2914). [myftptoyman]
 * Fix make support for gmake 3.x (#2920) (#2921). [Philipp Wagner]
@@ -186,10 +327,10 @@ Verilator 4.204 2021-06-12
 * Fix to emit 'else if' without nesting (#2944). [Geza Lore]
 * Fix part select issues in LATCH warning (#2948) (#2938). [Julien Margetts]
 * Fix to not emit empty files with low split limits (#2961). [Geza Lore]
-* Fix merging of assignments in C++ code (#2970). [Ruper Swarbrick]
+* Fix merging of assignments in C++ code (#2970). [Rupert Swarbrick]
 * Fix unused variable warnings (#2991). [Pieter Kapsenberg]
 * Fix --protect-ids when using SV classes (#2994). [Geza Lore]
-* Fix constant function calls with uninit value (#2995). [yanx21]
+* Fix constant function calls with uninitialized value (#2995). [yanx21]
 * Fix Makefiles to support Windows EXEEXT usage (#3008). [Miodrag Milanovic]


@@ -227,7 +368,7 @@ Verilator 4.202 2021-04-24
 * Fix Cygwin example compile issues (#2856). [Mark Shaw]
 * Fix select of with index variable (#2880). [Alexander Grobman]
 * Fix cmake version number to be numeric (#2881). [Yuri Victorovich]
-* Fix MinGW not supportting 'localtime_r' (#2882). [HyungKi Jeong]
+* Fix MinGW not supporting 'localtime_r' (#2882). [HyungKi Jeong]
 * Fix cast from packed, typedef'ed interface signal (#2884). [Todd Strader]
 * Fix VPI package reported as vpiModule (#2885). [Todd Strader]
 * Fix dumping waveforms to multiple FST files (#2889). [David Metz]
@@ -291,7 +432,7 @@ Verilator 4.108 2021-01-10
 **Major:**

 * Many VPI changes for IEEE compatibility, which may alter behavior from previous releases.
-* Support randomize() class method and rand (#2607). [Krzysztof Bieganski]
+* Support randomize() class method and rand (#2607). [Krzysztof Bieganski/Antmicro]

 **Minor:**

@@ -351,7 +492,7 @@ Verilator 4.104 2020-11-14
 * Support queue and associative array 'with' statements (#2616).
 * Support queue slicing (#2326).
 * Support associative array pattern assignments and defaults.
-* Support static methods and typedefs in classes (#2615). [Krzysztof Bieganski]
+* Support static methods and typedefs in classes (#2615). [Krzysztof Bieganski/Antmicro]
 * Add error on typedef referencing self (#2539). [Cody Piersall]
 * With --debug, turn off address space layout randomization.
 * Fix iteration over mutating list bug in VPI (#2588). [Kaleb Barrett]
@@ -374,7 +515,7 @@ Verilator 4.102 2020-10-15
 * Support # as a comment in -f files (#2497). [phantom-killua]
 * Support 'this' (#2585). [Rafal Kapuscik]
 * Support defines for FST tracing (#2592). [Markus Krause]
-* Support non-overapping implication inside properties (#1292). [Peter Monsson]
+* Support non-overlapping implication inside properties (#1292). [Peter Monsson]
 * Fix timescale with --hierarchical (#2554). [Yutetsu TAKATSUKASA]
 * Fix cmake build with --hierarchical (#2560). [Yutetsu TAKATSUKASA]
 * Fix -G dropping public indication (#2561). [Andrew Goessling]
@@ -400,7 +541,7 @@ Verilator 4.100 2020-09-07
 * Support (with limitations) class extern, class extends, virtual class.
 * Support $urandom, $urandom_range without stability.
 * Support assume property. [Peter Monsson]
-* Support non-overapping implication inside properties (#1292). [Peter Monsson]
+* Support non-overlapping implication inside properties (#1292). [Peter Monsson]
 * Fix false DECLFILENAME on black-boxed modules (#2430). [Philipp Wagner]
 * Fix naming of "id : begin" blocks.
 * Fix class constructor error on assignments to const.
@@ -322,7 +322,10 @@ cppcheck: $(CPPCHECK_DEP)
 	$(CPPCHECK) $(CPPCHECK_FLAGS) -DVL_DEBUG=1 -DVL_CPPCHECK=1 -DVL_THREADED=1 $(CPPCHECK_INC) $<

 CLANGTIDY = clang-tidy
-CLANGTIDY_FLAGS = -config='' -checks='-fuchsia-*,-cppcoreguidelines-avoid-c-arrays,-cppcoreguidelines-init-variables'
+CLANGTIDY_FLAGS = -config='' \
+	-header-filter='.*' \
+	-checks='-fuchsia-*,-cppcoreguidelines-avoid-c-arrays,-cppcoreguidelines-init-variables,-cppcoreguidelines-avoid-goto,-modernize-avoid-c-arrays,-readability-magic-numbers,-readability-simplify-boolean-expr,-cppcoreguidelines-macro-usage' \
+
 CLANGTIDY_DEP = $(subst .h,.h.tidy,$(CPPCHECK_H)) \
 	$(subst .cpp,.cpp.tidy,$(CPPCHECK_CPP))
 CLANGTIDY_DEFS = -DVL_DEBUG=1 -DVL_THREADED=1 -DVL_CPPCHECK=1
@@ -331,7 +334,7 @@ clang-tidy: $(CLANGTIDY_DEP)
 %.cpp.tidy: %.cpp
 	$(CLANGTIDY) $(CLANGTIDY_FLAGS) $< -- $(CLANGTIDY_DEFS) $(CPPCHECK_INC) | 2>&1 tee $@
 %.h.tidy: %.h
-	$(CLANGTIDY) $(CLANGTIDY_FLAGS) $< -- $(CLANGTIDY_DEFS) $(CPPCHECK_INC) | 2>&1 tee $@
+	$(CLANGTIDY) $(CLANGTIDY_FLAGS) $< -- $(CLANGTIDY_DEFS) $(CPPCHECK_INC) -x c++-header | 2>&1 tee $@

 analyzer-src:
 	-rm -rf src/obj_dbg
@@ -343,13 +346,13 @@ analyzer-include:

 format: clang-format yapf format-pl-exec

-CLANGFORMAT = clang-format-11
+CLANGFORMAT = clang-format-14
 CLANGFORMAT_FLAGS = -i
 CLANGFORMAT_FILES = $(CPPCHECK_CPP) $(CPPCHECK_H) $(CPPCHECK_YL) test_regress/t/*.c* test_regress/t/*.h

 clang-format:
-	@$(CLANGFORMAT) --version | egrep 11.0 > /dev/null \
-		|| echo "*** You are not using clang-format 11.0, indents may differ from master's ***"
+	@$(CLANGFORMAT) --version | egrep 14.0 > /dev/null \
+		|| echo "*** You are not using clang-format-14, indents may differ from master's ***"
 	$(CLANGFORMAT) $(CLANGFORMAT_FLAGS) $(CLANGFORMAT_FILES)

 PY_PROGRAMS = \
@@ -388,10 +391,10 @@ yapf:
 FLAKE8 = flake8
 FLAKE8_FLAGS = \
 	--extend-exclude=fastcov.py \
-	--ignore=E123,E129,E251,E501,W503,W504,E701
+	--ignore=E123,E129,E251,E402,E501,W503,W504,E701

 PYLINT = pylint
-PYLINT_FLAGS = --disable=R0801
+PYLINT_FLAGS = --score=n --disable=R0801

 lint-py:
 	-$(FLAKE8) $(FLAKE8_FLAGS) $(PY_PROGRAMS)
@@ -21,14 +21,14 @@ Welcome to Verilator
 .. list-table::

   * - **Welcome to Verilator, the fastest Verilog/SystemVerilog simulator.**
-        * Accepts synthesizable Verilog or SystemVerilog
+        * Accepts Verilog or SystemVerilog
        * Performs lint code-quality checks
        * Compiles into multithreaded C++, or SystemC
        * Creates XML to front-end your own tools
     - |Logo|
   * - |verilator multithreaded performance|
     - **Fast**
-        * Outperforms many commercial simulators
+        * Outperforms many closed-source commercial simulators
        * Single- and multi-threaded output models
   * - **Widely Used**
        * Wide industry and academic deployment
@@ -55,25 +55,25 @@ performing lint checks, and optionally inserting assertion checks and
 coverage-analysis points. It outputs single- or multi-threaded .cpp and .h
 files, the "Verilated" code.

-The user writes a little C++/SystemC wrapper file, which instantiates the
-"Verilated" model of the user's top level module. These C++/SystemC files
-are then compiled by a C++ compiler (gcc/clang/MSVC++). The resulting
-executable performs the design simulation. Verilator also supports linking
-its generated libraries, optionally encrypted, into other simulators.
+These Verilated C++/SystemC files are then compiled by a C++ compiler
+(gcc/clang/MSVC++), optionally along with a user's own C++/SystemC wrapper
+file to instantiate the Verilated model. Executing the resulting executable
+performs the design simulation. Verilator also supports linking Verilated
+generated libraries, optionally encrypted, into other simulators.

 Verilator may not be the best choice if you are expecting a full featured
-replacement for NC-Verilog, VCS or another commercial Verilog simulator, or
-if you are looking for a behavioral Verilog simulator e.g. for a quick
-class project (we recommend `Icarus Verilog`_ for this.) However, if you
-are looking for a path to migrate SystemVerilog to C++ or SystemC, or your
-team is comfortable writing just a touch of C++ code, Verilator is the tool
-for you.
+replacement for a closed-source Verilog simulator, need SDF annotation,
+mixed-signal simulation, or are doing a quick class project (we recommend
+`Icarus Verilog`_ for classwork.)  However, if you are looking for a path
+to migrate SystemVerilog to C++/SystemC, or want high speed simulation of
+synthesizable designs containing limited verification constructs, Verilator
+is the tool for you.


 Performance
 ===========

-Verilator does not simply convert Verilog HDL to C++ or SystemC. Rather,
+Verilator does not directly translate Verilog HDL to C++ or SystemC. Rather,
 Verilator compiles your code into a much faster optimized and optionally
 thread-partitioned model, which is in turn wrapped inside a C++/SystemC
 module. The results are a compiled Verilog model that executes even on a
@@ -84,9 +84,11 @@ multithreading (yielding 200-1000x total over interpreted simulators).

 Verilator has typically similar or better performance versus the
 closed-source Verilog simulators (Carbon Design Systems Carbonator,
-Modelsim, Cadence Incisive/NC-Verilog, Synopsys VCS, VTOC, and Pragmatic
-CVer/CVC). But, Verilator is open-sourced, so you can spend on computes
-rather than licenses. Thus Verilator gives you the best cycles/dollar.
+Modelsim/Questa, Cadence Incisive/NC-Verilog, Synopsys VCS, VTOC, and
+Pragmatic CVer/CVC). But, Verilator is open-sourced, so you can spend on
+computes rather than licenses. Thus Verilator gives you the best
+cycles/dollar.
+

 Installation & Documentation
 ============================
@@ -282,35 +282,40 @@ detailed descriptions of these arguments.
    --autoflush                 Flush streams after all $displays
    --bbox-sys                  Blackbox unknown $system calls
    --bbox-unsup                Blackbox unsupported language features
-    --bin <filename>            Override Verilator binary
    --build                     Build model executable/library after Verilation
-     -CFLAGS <flags>            C++ compiler arguments for makefile
+    --build-dep-bin <filename>  Override build dependency Verilator binary
+    --build-jobs <jobs>         Parallelism for --build
    --cc                        Create C++ output
    --cdc                       Clock domain crossing analysis
+     -CFLAGS <flags>            C++ compiler arguments for makefile
    --clk <signal-name>         Mark specified signal as clock
-    --make <build-tool>         Generate scripts for specified build tool
+    --no-clk <signal-name>      Prevent marking specified signal as clock
    --compiler <compiler-name>  Tune for specified C++ compiler
    --converge-limit <loops>    Tune convergence settle time
    --coverage                  Enable all coverage
    --coverage-line             Enable line coverage
    --coverage-max-width <width>   Maximum array depth for coverage
    --coverage-toggle           Enable toggle coverage
-    --coverage-user             Enable SVL user coverage
    --coverage-underscore       Enable coverage of _signals
+    --coverage-user             Enable SVL user coverage
     -D<var>[=<value>]          Set preprocessor define
    --debug                     Enable debugging
    --debug-check               Enable debugging assertions
    --no-debug-leak             Disable leaking memory in --debug mode
    --debugi <level>            Enable debugging at a specified level
    --debugi-<srcfile> <level>  Enable debugging a source file at a level
+    --no-decoration             Disable comments and symbol decorations
    --default-language <lang>   Default language to parse
     +define+<var>=<value>      Set preprocessor define
    --dpi-hdr-only              Only produce the DPI header file
    --dump-defines              Show preprocessor defines with -E
-    --dump-tree                 Enable dumping .tree files
-    --dump-treei <level>        Enable dumping .tree files at a level
-    --dump-treei-<srcfile> <level>  Enable dumping .tree file at a source file at a level
+    --dump-graph                Enable dumping V3Graphs to .dot
+    --dump-tree                 Enable dumping Ast .tree files
    --dump-tree-addrids         Use short identifiers instead of addresses
+    --dump-<srcfile>            Enable dumping everything in source file
+    --dumpi-graph <level>       Enable dumping V3Graphs to .dot files at level
+    --dumpi-tree <level>        Enable dumping Ast .tree files at level
+    --dumpi-<srcfile> <level>   Enable dumping everything in source file at level
     -E                         Preprocess, but do not compile
    --error-limit <value>       Abort after this number of errors
    --exe                       Link to create executable
@@ -319,7 +324,9 @@ detailed descriptions of these arguments.
     -f <file>                  Parse arguments from a file
     -FI <file>                 Force include of a file
    --flatten                   Force inlining of all modules, tasks and functions
+     -fno-<optimization>        Disable internal optimization stage
     -G<name>=<value>           Overwrite top-level parameter
+    --gate-stmts <value>        Tune gate optimizer depth
    --gdb                       Run Verilator under GDB interactively
    --gdbbt                     Run Verilator under GDB for backtrace
    --generate-key              Create random key for --protect-key
@@ -327,54 +334,52 @@ detailed descriptions of these arguments.
    --help                      Display this help
    --hierarchical              Enable hierarchical Verilation
     -I<dir>                    Directory to search for includes
-     -j <jobs>                  Parallelism for --build
-    --gate-stmts <value>        Tune gate optimizer depth
    --if-depth <value>          Tune IFDEPTH warning
     +incdir+<dir>              Directory to search for includes
    --inline-mult <value>       Tune module inlining
    --instr-count-dpi <value>   Assumed dynamic instruction count of DPI imports
-     -LDFLAGS <flags>           Linker pre-object arguments for makefile
+     -j <jobs>                  Parallelism for --build (alias to --build-jobs)
    --l2-name <value>           Verilog scope name of the top module
    --language <lang>           Default language standard to parse
+     -LDFLAGS <flags>           Linker pre-object arguments for makefile
    --lib-create <name>         Create a DPI library
     +libext+<ext>+[ext]...     Extensions for finding modules
    --lint-only                 Lint, but do not make output
+    --make <build-tool>         Generate scripts for specified build tool
     -MAKEFLAGS <flags>         Arguments to pass to make during --build
+    --main                      Generate C++ main() file
    --max-num-width <value>     Maximum number width (default: 64K)
-    --MMD                       Create .d dependency files
-    --MP                        Create phony dependency targets
    --Mdir <directory>          Name of output object directory
-    --no-merge-const-pool       Disable merging of different types in const pool
+    --MMD                       Create .d dependency files
    --mod-prefix <topname>      Name to prepend to lower classes
-    --no-clk <signal-name>      Prevent marking specified signal as clock
-    --no-decoration             Disable comments and symbol decorations
-    --no-pins64                 Don't use vluint64_t's for 33-64 bit sigs
-    --no-skip-identical         Disable skipping identical output
+    --MP                        Create phony dependency targets
     +notimingchecks            Ignored
     -O0                        Disable optimizations
     -O3                        High performance optimizations
     -O<optimization-letter>    Selectable optimizations
     -o <executable>            Name of final executable
    --no-order-clock-delay      Disable ordering clock enable assignments
-    --no-verilate               Skip verilation and just compile previously Verilated code.
+    --no-verilate               Skip Verilation, only compile previously Verilated code
    --output-split <statements>          Split .cpp files into pieces
    --output-split-cfuncs <statements>   Split model functions
    --output-split-ctrace <statements>   Split tracing functions
     -P                         Disable line numbers and blanks with -E
    --pins-bv <bits>            Specify types for top level ports
-    --pins-sc-uint              Specify types for top level ports
    --pins-sc-biguint           Specify types for top level ports
+    --pins-sc-uint              Specify types for top level ports
    --pins-uint8                Specify types for top level ports
+    --no-pins64                 Don't use uint64_t's for 33-64 bit sigs
    --pipe-filter <command>     Filter all input through a script
    --pp-comments               Show preprocessor comments with -E
    --prefix <topname>          Name of top level class
+    --private                   Debugging; see docs
    --prof-c                    Compile C++ code with profiling
    --prof-cfuncs               Name functions for profiling
-    --prof-threads              Enable generating gantt chart data for threads
-    --protect-key <key>         Key for symbol protection
+    --prof-exec                 Enable generating execution profile for gantt chart
+    --prof-pgo                  Enable generating profiling data for PGO
    --protect-ids               Hash identifier names for obscurity
+    --protect-key <key>         Key for symbol protection
    --protect-lib <name>        Create a DPI protected library
-    --private                   Debugging; see docs
    --public                    Debugging; see docs
    --public-flat-rw            Mark all variables, etc as public_flat_rw
     -pvalue+<name>=<value>     Overwrite toplevel parameter
@@ -385,6 +390,7 @@ detailed descriptions of these arguments.
    --rr                        Run Verilator and record with rr
    --savable                   Enable model save-restore
    --sc                        Create SystemC output
+    --no-skip-identical         Disable skipping identical output
    --stats                     Create statistics file
    --stats-vars                Provide statistics on variables
     -sv                        Enable SystemVerilog parsing
@@ -404,7 +410,7 @@ detailed descriptions of these arguments.
    --trace-max-width <width>   Maximum array depth for tracing
    --trace-params              Enable tracing of parameters
    --trace-structs             Enable tracing structure names
-    --trace-threads <threads>   Enable waveform creation on separate threads
+    --trace-threads <threads>   Enable FST waveform creation on separate threads
    --trace-underscore          Enable tracing of _signals
     -U<var>                    Undefine preprocessor define
    --unroll-count <loops>      Tune maximum loop iterations
@@ -412,6 +418,7 @@ detailed descriptions of these arguments.
    --unused-regexp <regexp>    Tune UNUSED lint signals
     -V                         Verbose version and config
     -v <filename>              Verilog library
+    --no-verilate               Skip verilation and just compile previously Verilated code.
     +verilog1995ext+<ext>      Synonym for +1364-1995ext+<ext>
     +verilog2001ext+<ext>      Synonym for +1364-2001ext+<ext>
    --version                   Displays program version and exits
@@ -426,6 +433,9 @@ detailed descriptions of these arguments.
     -Wno-lint                  Disable all lint warnings
     -Wno-style                 Disable all style warnings
     -Wpedantic                 Warn on compliance-test issues
+     -Wwarn-<message>           Enable specified warning message
+     -Wwarn-lint                Enable lint warning message
+     -Wwarn-style               Enable style warning message
    --x-assign <mode>           Assign non-initial Xs to this value
    --x-initial <mode>          Assign initial Xs to this value
    --x-initial-edge            Enable initial X->0 and X->1 edge triggers
@@ -445,10 +455,10 @@ description of these arguments.
     +verilator+error+limit+<value>    Set error limit
     +verilator+help                   Display help
     +verilator+noassert               Disable assert checking
-     +verilator+prof+threads+file+<filename>  Set profile filename
-     +verilator+prof+threads+start+<value>    Set profile starting point
-     +verilator+prof+threads+window+<value>   Set profile duration
-     +verilator+prof+vlt+file+<filename>      Set profile guided filename
+     +verilator+prof+exec+file+<filename>  Set execution profile filename
+     +verilator+prof+exec+start+<value>    Set execution profile starting point
+     +verilator+prof+exec+window+<value>   Set execution profile duration
+     +verilator+prof+vlt+file+<filename>   Set PGO profile filename
     +verilator+rand+reset+<value>     Set random reset technique
     +verilator+seed+<value>           Set random seed
     +verilator+V                      Verbose version and config
@@ -38,10 +38,10 @@ def diff_dir(a, b):

    anyfile = False
    for base in sorted(files.keys()):
+        if ('a' not in files[base]) or ('b' not in files[base]):
+            continue
        a = files[base]['a']
        b = files[base]['b']
-        if not a or not b:
-            continue
        print("=" * 70)
        print("= %s <-> %s" % (a, b))
        diff_file(a, b)
@@ -9,7 +9,7 @@ import re
 import statistics
 # from pprint import pprint

-Threads = collections.defaultdict(lambda: {})
+Threads = collections.defaultdict(lambda: collections.defaultdict(lambda: {}))
 Mtasks = collections.defaultdict(lambda: {})
 Evals = collections.defaultdict(lambda: {})
 EvalLoops = collections.defaultdict(lambda: {})
@@ -30,12 +30,12 @@ def process(filename):

 def read_data(filename):
    with open(filename) as fh:
-        re_prof = re.compile(
-            r'^VLPROF mtask\s(\d+)\sstart\s(\d+)\selapsed\s(\d+)\spredict_start\s(\d+)\spredict_cost\s(\d+)\scpu\s(\d+)\son thread (\d+)'
-        )
-        re_eval = re.compile(r'^VLPROF eval\sstart\s(\d+)\selapsed\s(\d+)')
-        re_loop = re.compile(
-            r'^VLPROF eval_loop\sstart\s(\d+)\selapsed\s(\d+)')
+        re_thread = re.compile(r'^VLPROFTHREAD (\d+)$')
+        re_record = re.compile(r'^VLPROFEXEC (\S+) (\d+)(.*)$')
+        re_payload_mtaskBegin = re.compile(
+            r'id (\d+) predictStart (\d+) cpu (\d+)')
+        re_payload_mtaskEnd = re.compile(r'id (\d+) predictCost (\d+)')
+
        re_arg1 = re.compile(r'VLPROF arg\s+(\S+)\+([0-9.]*)\s*')
        re_arg2 = re.compile(r'VLPROF arg\s+(\S+)\s+([0-9.]*)\s*$')
        re_stat = re.compile(r'VLPROF stat\s+(\S+)\s+([0-9.]+)')
@@ -43,47 +43,60 @@ def read_data(filename):
        re_proc_cpu = re.compile(r'VLPROFPROC processor\s*:\s*(\d+)\s*$')
        re_proc_dat = re.compile(r'VLPROFPROC ([a-z_ ]+)\s*:\s*(.*)$')
        cpu = None
+        thread = None
+
+        lastEvalBeginTick = None
+        lastEvalLoopBeginTick = None

        for line in fh:
-            if re_prof.match(line):
-                match = re_prof.match(line)
-                mtask = int(match.group(1))
-                start = int(match.group(2))
-                elapsed_time = int(match.group(3))
-                end = start + elapsed_time
-                predict_start = int(match.group(4))
-                predict_cost = int(match.group(5))
-                cpu = int(match.group(6))
-                thread = int(match.group(7))
-                if start not in Threads[thread]:
-                    Threads[thread][start] = {}
-                Threads[thread][start]['mtask'] = mtask
-                Threads[thread][start]['end'] = end
-                Threads[thread][start]['cpu'] = cpu
-                Threads[thread][start]['predict_start'] = predict_start
-                Threads[thread][start]['predict_cost'] = predict_cost
-
-                if 'elapsed' not in Mtasks[mtask]:
-                    Mtasks[mtask] = {'end': 0, 'elapsed': 0}
-                Mtasks[mtask]['thread'] = thread
-                Mtasks[mtask]['elapsed'] += elapsed_time
-                Mtasks[mtask]['predict_start'] = predict_start
-                Mtasks[mtask]['predict_cost'] = predict_cost
-                Mtasks[mtask]['end'] = max(Mtasks[mtask]['end'], end)
-            elif re_eval.match(line):
-                match = re_eval.match(line)
-                start = int(match.group(1))
-                elapsed_time = int(match.group(2))
-                Evals[start]['start'] = start
-                Evals[start]['end'] = start + elapsed_time
-            elif re_loop.match(line):
-                match = re_loop.match(line)
-                start = int(match.group(1))
-                elapsed_time = int(match.group(2))
-                EvalLoops[start]['start'] = start
-                EvalLoops[start]['end'] = start + elapsed_time
-            elif re.match(r'^VLPROFTHREAD', line):
-                None  # pylint: disable=pointless-statement
+            recordMatch = re_record.match(line)
+            if recordMatch:
+                kind, tick, payload = recordMatch.groups()
+                tick = int(tick)
+                payload = payload.strip()
+                if kind == "EVAL_BEGIN":
+                    Evals[tick]['start'] = tick
+                    lastEvalBeginTick = tick
+                elif kind == "EVAL_END":
+                    Evals[lastEvalBeginTick]['end'] = tick
+                    lastEvalBeginTick = None
+                elif kind == "EVAL_LOOP_BEGIN":
+                    EvalLoops[tick]['start'] = tick
+                    lastEvalLoopBeginTick = tick
+                elif kind == "EVAL_LOOP_END":
+                    EvalLoops[lastEvalLoopBeginTick]['end'] = tick
+                    lastEvalLoopBeginTick = None
+                elif kind == "MTASK_BEGIN":
+                    mtask, predict_start, ecpu = re_payload_mtaskBegin.match(
+                        payload).groups()
+                    mtask = int(mtask)
+                    predict_start = int(predict_start)
+                    ecpu = int(ecpu)
+                    Threads[thread][tick]['mtask'] = mtask
+                    Threads[thread][tick]['predict_start'] = predict_start
+                    Threads[thread][tick]['cpu'] = ecpu
+                    if 'elapsed' not in Mtasks[mtask]:
+                        Mtasks[mtask] = {'end': 0, 'elapsed': 0}
+                    Mtasks[mtask]['begin'] = tick
+                    Mtasks[mtask]['thread'] = thread
+                    Mtasks[mtask]['predict_start'] = predict_start
+                elif kind == "MTASK_END":
+                    mtask, predict_cost = re_payload_mtaskEnd.match(
+                        payload).groups()
+                    mtask = int(mtask)
+                    predict_cost = int(predict_cost)
+                    begin = Mtasks[mtask]['begin']
+                    Threads[thread][begin]['end'] = tick
+                    Threads[thread][begin]['predict_cost'] = predict_cost
+                    Mtasks[mtask]['elapsed'] += tick - begin
+                    Mtasks[mtask]['predict_cost'] = predict_cost
+                    Mtasks[mtask]['end'] = max(Mtasks[mtask]['end'], tick)
+                elif Args.debug:
+                    print("-Unknown execution trace record: %s" % line)
+            elif re_thread.match(line):
+                thread = int(re_thread.match(line).group(1))
+            elif re.match(r'^VLPROF(THREAD|VERSION)', line):
+                pass
            elif re_arg1.match(line):
                match = re_arg1.match(line)
                Global['args'][match.group(1)] = match.group(2)
@@ -105,7 +118,7 @@ def read_data(filename):
                value = re.sub(r'\s+$', '', value)
                Global['cpuinfo'][cpu][term] = value
            elif re.match(r'^#', line):
-                None  # pylint: disable=pointless-statement
+                pass
            elif Args.debug:
                print("-Unk: %s" % line)
            # TODO -- this is parsing text printed by a client.
@@ -131,11 +144,13 @@ def report():
        plus = "+" if re.match(r'^\+', arg) else " "
        print("  %s%s%s" % (arg, plus, Global['args'][arg]))

-    nthreads = len(Threads)
+    nthreads = int(Global['stats']['threads'])
    Global['cpus'] = {}
    for thread in Threads:
        # Make potentially multiple characters per column
        for start in Threads[thread]:
+            if not Threads[thread][start]:
+                continue
            cpu = Threads[thread][start]['cpu']
            elapsed = Threads[thread][start]['end'] - start
            if cpu not in Global['cpus']:
@@ -169,74 +184,79 @@ def report():
    print("\nAnalysis:")
    print("  Total threads             = %d" % nthreads)
    print("  Total mtasks              = %d" % len(Mtasks))
-    ncpus = len(Global['cpus'])
+    ncpus = max(len(Global['cpus']), 1)
    print("  Total cpus used           = %d" % ncpus)
-    print("  Total yields              = %d" % int(Global['stats']['yields']))
+    print("  Total yields              = %d" %
+          int(Global['stats'].get('yields', 0)))
    print("  Total evals               = %d" % len(Evals))
    print("  Total eval loops          = %d" % len(EvalLoops))
-    print("  Total eval time           = %d rdtsc ticks" %
-          Global['measured_last_end'])
-    print("  Longest mtask time        = %d rdtsc ticks" % long_mtask_time)
-    print("  All-thread mtask time     = %d rdtsc ticks" %
-          measured_mt_mtask_time)
-    long_efficiency = long_mtask_time / (Global.get('measured_last_end', 1)
-                                         or 1)
-    print("  Longest-thread efficiency = %0.1f%%" % (long_efficiency * 100.0))
-    mt_efficiency = measured_mt_mtask_time / (
-        Global.get('measured_last_end', 1) * nthreads or 1)
-    print("  All-thread efficiency     = %0.1f%%" % (mt_efficiency * 100.0))
-    print("  All-thread speedup        = %0.1f" % (mt_efficiency * nthreads))
-    if Global['rdtsc_cycle_time'] > 0:
-        ut = measured_mt_mtask_time / Global['rdtsc_cycle_time']
-        print("tot_mtask_cpu=" + measured_mt_mtask_time + " cyc=" +
-              Global['rdtsc_cycle_time'] + " ut=" + ut)
+    if Mtasks:
+        print("  Total eval time           = %d rdtsc ticks" %
+              Global['measured_last_end'])
+        print("  Longest mtask time        = %d rdtsc ticks" % long_mtask_time)
+        print("  All-thread mtask time     = %d rdtsc ticks" %
+              measured_mt_mtask_time)
+        long_efficiency = long_mtask_time / (Global.get(
+            'measured_last_end', 1) or 1)
+        print("  Longest-thread efficiency = %0.1f%%" %
+              (long_efficiency * 100.0))
+        mt_efficiency = measured_mt_mtask_time / (
+            Global.get('measured_last_end', 1) * nthreads or 1)
+        print("  All-thread efficiency     = %0.1f%%" %
+              (mt_efficiency * 100.0))
+        print("  All-thread speedup        = %0.1f" %
+              (mt_efficiency * nthreads))
+        if Global['rdtsc_cycle_time'] > 0:
+            ut = measured_mt_mtask_time / Global['rdtsc_cycle_time']
+            print("tot_mtask_cpu=" + measured_mt_mtask_time + " cyc=" +
+                  Global['rdtsc_cycle_time'] + " ut=" + ut)

-    predict_mt_efficiency = predict_mt_mtask_time / (
-        Global.get('predict_last_end', 1) * nthreads or 1)
-    print("\nPrediction (what Verilator used for scheduling):")
-    print("  All-thread efficiency     = %0.1f%%" %
-          (predict_mt_efficiency * 100.0))
-    print("  All-thread speedup        = %0.1f" %
-          (predict_mt_efficiency * nthreads))
+        predict_mt_efficiency = predict_mt_mtask_time / (
+            Global.get('predict_last_end', 1) * nthreads or 1)
+        print("\nPrediction (what Verilator used for scheduling):")
+        print("  All-thread efficiency     = %0.1f%%" %
+              (predict_mt_efficiency * 100.0))
+        print("  All-thread speedup        = %0.1f" %
+              (predict_mt_efficiency * nthreads))

-    p2e_ratios = []
-    min_p2e = 1000000
-    min_mtask = None
-    max_p2e = -1000000
-    max_mtask = None
+        p2e_ratios = []
+        min_p2e = 1000000
+        min_mtask = None
+        max_p2e = -1000000
+        max_mtask = None

-    for mtask in sorted(Mtasks.keys()):
-        if Mtasks[mtask]['elapsed'] > 0:
-            if Mtasks[mtask]['predict_cost'] == 0:
-                Mtasks[mtask]['predict_cost'] = 1  # don't log(0) below
-            p2e_ratio = math.log(Mtasks[mtask]['predict_cost'] /
-                                 Mtasks[mtask]['elapsed'])
-            p2e_ratios.append(p2e_ratio)
+        for mtask in sorted(Mtasks.keys()):
+            if Mtasks[mtask]['elapsed'] > 0:
+                if Mtasks[mtask]['predict_cost'] == 0:
+                    Mtasks[mtask]['predict_cost'] = 1  # don't log(0) below
+                p2e_ratio = math.log(Mtasks[mtask]['predict_cost'] /
+                                     Mtasks[mtask]['elapsed'])
+                p2e_ratios.append(p2e_ratio)

-            if p2e_ratio > max_p2e:
-                max_p2e = p2e_ratio
-                max_mtask = mtask
-            if p2e_ratio < min_p2e:
-                min_p2e = p2e_ratio
-                min_mtask = mtask
+                if p2e_ratio > max_p2e:
+                    max_p2e = p2e_ratio
+                    max_mtask = mtask
+                if p2e_ratio < min_p2e:
+                    min_p2e = p2e_ratio
+                    min_mtask = mtask

-    print("\nStatistics:")
-    print("  min log(p2e) = %0.3f" % min_p2e, end="")
-    print("  from mtask %d (predict %d," %
-          (min_mtask, Mtasks[min_mtask]['predict_cost']),
-          end="")
-    print(" elapsed %d)" % Mtasks[min_mtask]['elapsed'])
-    print("  max log(p2e) = %0.3f" % max_p2e, end="")
-    print("  from mtask %d (predict %d," %
-          (max_mtask, Mtasks[max_mtask]['predict_cost']),
-          end="")
-    print(" elapsed %d)" % Mtasks[max_mtask]['elapsed'])
+        print("\nMTask statistics:")
+        print("  min log(p2e) = %0.3f" % min_p2e, end="")
+        print("  from mtask %d (predict %d," %
+              (min_mtask, Mtasks[min_mtask]['predict_cost']),
+              end="")
+        print(" elapsed %d)" % Mtasks[min_mtask]['elapsed'])
+        print("  max log(p2e) = %0.3f" % max_p2e, end="")
+        print("  from mtask %d (predict %d," %
+              (max_mtask, Mtasks[max_mtask]['predict_cost']),
+              end="")
+        print(" elapsed %d)" % Mtasks[max_mtask]['elapsed'])

-    stddev = statistics.pstdev(p2e_ratios)
-    mean = statistics.mean(p2e_ratios)
-    print("  mean = %0.3f" % mean)
-    print("  stddev = %0.3f" % stddev)
-    print("  e ^ stddev = %0.3f" % math.exp(stddev))
+        stddev = statistics.pstdev(p2e_ratios)
+        mean = statistics.mean(p2e_ratios)
+        print("  mean = %0.3f" % mean)
+        print("  stddev = %0.3f" % stddev)
+        print("  e ^ stddev = %0.3f" % math.exp(stddev))

    report_cpus()

@@ -375,44 +395,45 @@ def write_vcd(filename):
            vcd['values'][eval_start][elcode] = n
            vcd['values'][eval_end][elcode] = None

-        # Predicted graph
-        for eval_start in EvalLoops:
-            eval_end = EvalLoops[eval_start]['end']
-            # Compute scale so predicted graph is of same width as eval
-            measured_scaling = (eval_end -
-                                eval_start) / Global['predict_last_end']
-            # Predict mtasks that fill the time the eval occupied
-            for mtask in Mtasks:
-                thread = Mtasks[mtask]['thread']
-                pred_scaled_start = eval_start + int(
-                    Mtasks[mtask]['predict_start'] * measured_scaling)
-                pred_scaled_end = eval_start + int(
-                    (Mtasks[mtask]['predict_start'] +
-                     Mtasks[mtask]['predict_cost']) * measured_scaling)
-                if pred_scaled_start == pred_scaled_end:
-                    continue
+        if Mtasks:
+            # Predicted graph
+            for eval_start in EvalLoops:
+                eval_end = EvalLoops[eval_start]['end']
+                # Compute scale so predicted graph is of same width as eval
+                measured_scaling = (eval_end -
+                                    eval_start) / Global['predict_last_end']
+                # Predict mtasks that fill the time the eval occupied
+                for mtask in Mtasks:
+                    thread = Mtasks[mtask]['thread']
+                    pred_scaled_start = eval_start + int(
+                        Mtasks[mtask]['predict_start'] * measured_scaling)
+                    pred_scaled_end = eval_start + int(
+                        (Mtasks[mtask]['predict_start'] +
+                         Mtasks[mtask]['predict_cost']) * measured_scaling)
+                    if pred_scaled_start == pred_scaled_end:
+                        continue

-                sig = "predicted_thread%d_mtask" % thread
-                if sig not in vcd['sigs']['predicted_threads']:
-                    vcd['sigs']['predicted_threads'][sig] = code
-                    code += 1
-                mcode = vcd['sigs']['predicted_threads'][sig]
+                    sig = "predicted_thread%d_mtask" % thread
+                    if sig not in vcd['sigs']['predicted_threads']:
+                        vcd['sigs']['predicted_threads'][sig] = code
+                        code += 1
+                    mcode = vcd['sigs']['predicted_threads'][sig]

-                vcd['values'][pred_scaled_start][mcode] = mtask
-                vcd['values'][pred_scaled_end][mcode] = None
+                    vcd['values'][pred_scaled_start][mcode] = mtask
+                    vcd['values'][pred_scaled_end][mcode] = None

-                parallelism['predicted'][pred_scaled_start] += 1
-                parallelism['predicted'][pred_scaled_end] -= 1
+                    parallelism['predicted'][pred_scaled_start] += 1
+                    parallelism['predicted'][pred_scaled_end] -= 1

-        # Parallelism graph
-        for measpred in ('measured', 'predicted'):
-            vcd['sigs']['Stats']["%s_parallelism" % measpred] = code
-            pcode = code
-            code += 1
-            value = 0
-            for time in sorted(parallelism[measpred].keys()):
-                value += parallelism[measpred][time]
-                vcd['values'][time][pcode] = value
+            # Parallelism graph
+            for measpred in ('measured', 'predicted'):
+                vcd['sigs']['Stats']["%s_parallelism" % measpred] = code
+                pcode = code
+                code += 1
+                value = 0
+                for time in sorted(parallelism[measpred].keys()):
+                    value += parallelism[measpred][time]
+                    vcd['values'][time][pcode] = value

        # Create output file
        fh.write("$version Generated by verilator_gantt $end\n")
@@ -476,10 +497,10 @@ parser.add_argument('--no-vcd',
                    action='store_true')
 parser.add_argument('--vcd',
                    help='filename for vcd outpue',
-                    default='profile_threads.vcd')
+                    default='profile_exec.vcd')
 parser.add_argument('filename',
-                    help='input profile_threads.dat filename to process',
-                    default='profile_threads.dat')
+                    help='input profile_exec.dat filename to process',
+                    default='profile_exec.dat')

 Args = parser.parse_args()

@@ -19,6 +19,10 @@ set -x

 cd $(dirname "$0")/..

+# Avoid occasional cpan failures "Issued certificate has expired."
+export PERL_LWP_SSL_VERIFY_HOSTNAME=0
+echo "check_certificate = off" >> ~/.wgetrc
+
 fatal() {
  echo "ERROR: $(basename "$0"): $1" >&2; exit 1;
 }
@@ -54,8 +58,12 @@ if [ "$CI_BUILD_STAGE_NAME" = "build" ]; then

  if [ "$CI_OS_NAME" = "linux" ]; then
    sudo apt-get update
-    sudo apt-get install libfl-dev libgoogle-perftools-dev ccache
-    if [ "$CI_RUNS_ON" = "ubuntu-20.04" ]; then
+    sudo apt-get install libfl-dev ccache
+    if [ "$CI_RUNS_ON" != "ubuntu-22.04" ]; then
+      # Some conflict of libunwind verison on 22.04, can live without it for now
+      sudo apt-get install libgoogle-perftools-dev
+    fi
+    if [ "$CI_RUNS_ON" = "ubuntu-20.04" ] || [ "$CI_RUNS_ON" = "ubuntu-22.04" ]; then
      sudo apt-get install libsystemc libsystemc-dev
    fi
    if [ "$COVERAGE" = 1 ]; then
@@ -85,7 +93,7 @@ elif [ "$CI_BUILD_STAGE_NAME" = "test" ]; then
    sudo apt-get update
    # libfl-dev needed for internal coverage's test runs
    sudo apt-get install gdb gtkwave lcov libfl-dev ccache
-    if [ "$CI_RUNS_ON" = "ubuntu-20.04" ]; then
+    if [ "$CI_RUNS_ON" = "ubuntu-20.04" ] || [ "$CI_RUNS_ON" = "ubuntu-22.04" ]; then
      sudo apt-get install libsystemc-dev
    fi
    if [ "$CI_M32" = 1 ]; then
@@ -6,7 +6,7 @@
 # Version 2.0.
 # SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0

-FROM ubuntu:20.04
+FROM ubuntu:22.04

 RUN apt-get update \
    && DEBIAN_FRONTEND=noninteractive \
@@ -8,7 +8,7 @@ Verilator build. It uses the following parameters:

 -  Source revision (default: master)

-  Compiler (GCC 9.3.0, clang 10.0.0, default: 9.3.0)
+-  Compiler (GCC 10.3.0, clang 10.0.0, default: 10.3.0)

 The container is published as ``verilator/verilator-buildenv`` on `docker
 hub
@@ -6,7 +6,7 @@
 # Version 2.0.
 # SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0

-FROM ubuntu:20.04
+FROM ubuntu:22.04

 RUN apt-get update \
    && DEBIAN_FRONTEND=noninteractive \
@@ -5,16 +5,16 @@
 # General Public License Version 3 or the Perl Artistic License Version 2.0.
 # SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0

-#AC_INIT([Verilator],[#.### YYYY-MM-DD])
-#AC_INIT([Verilator],[#.### devel])
-AC_INIT([Verilator],[4.218 2022-01-17],
-        [https://verilator.org],
-        [verilator],[https://verilator.org])
 # When releasing, also update header of Changes file
 # and commit using "devel release" or "Version bump" message
 # Then 'make maintainer-dist'
+#AC_INIT([Verilator],[#.### YYYY-MM-DD])
+#AC_INIT([Verilator],[#.### devel])
+AC_INIT([Verilator],[4.228 2022-10-01],
+        [https://verilator.org],
+        [verilator],[https://verilator.org])

-AC_CONFIG_HEADER(src/config_build.h)
+AC_CONFIG_HEADERS(src/config_build.h)
 AC_CONFIG_FILES(Makefile src/Makefile src/Makefile_obj include/verilated.mk include/verilated_config.h verilator.pc verilator-config.cmake verilator-config-version.cmake)

 # Version
@@ -22,6 +22,8 @@ AC_MSG_RESULT([configuring for $PACKAGE_STRING])
 PACKAGE_VERSION_NUMBER=`AS_ECHO("$PACKAGE_VERSION") | sed 's/ .*//g'`
 AC_SUBST(PACKAGE_VERSION_NUMBER)
 AC_DEFINE_UNQUOTED([PACKAGE_VERSION_NUMBER_STRING],["$PACKAGE_VERSION_NUMBER"],[Package version as a number])
+VERILATOR_VERSION_INTEGER=`AS_ECHO("$PACKAGE_VERSION") | [sed 's/\([0-9]\)\.\([0-9][0-9][0-9]\) .*/\1\2000/g']`
+AC_SUBST(VERILATOR_VERSION_INTEGER)

 # Ignore automake flags passed by Ubuntu builds
 AC_ARG_ENABLE([dependency-tracking],
@@ -346,14 +348,18 @@ AC_SUBST(CFG_CXXFLAGS_PROFILE)

 # Flag to select newest language standard supported
 # Macros work such that first option that passes is the one we take
-# Currently enabled c++14 due to packaged SystemC dependency
-# c++14 is the newest that Verilator is regressed to support
+# Currently enable c++17/c++14 due to packaged SystemC dependency
+# c++17 is the newest that Verilator is regularly tested to support
 # c++11 is the oldest that Verilator supports
 # gnu is requried for Cygwin to compile verilated.h successfully
 #_MY_CXX_CHECK_SET(CFG_CXXFLAGS_STD_NEWEST,-std=gnu++20)
 #_MY_CXX_CHECK_SET(CFG_CXXFLAGS_STD_NEWEST,-std=c++20)
-#_MY_CXX_CHECK_SET(CFG_CXXFLAGS_STD_NEWEST,-std=gnu++17)
-#_MY_CXX_CHECK_SET(CFG_CXXFLAGS_STD_NEWEST,-std=c++17)
+case "$(which lsb_release 2>&1 > /dev/null && lsb_release -d)" in
+*Arch*Linux* | *Ubuntu*22.04*)
+_MY_CXX_CHECK_SET(CFG_CXXFLAGS_STD_NEWEST,-std=gnu++17)
+_MY_CXX_CHECK_SET(CFG_CXXFLAGS_STD_NEWEST,-std=c++17)
+;;
+esac
 _MY_CXX_CHECK_SET(CFG_CXXFLAGS_STD_NEWEST,-std=gnu++14)
 _MY_CXX_CHECK_SET(CFG_CXXFLAGS_STD_NEWEST,-std=c++14)
 _MY_CXX_CHECK_SET(CFG_CXXFLAGS_STD_NEWEST,-std=gnu++11)
@@ -2,3 +2,4 @@
 *.html
 *.pdf
 _build
+guide/spelling.txt
@@ -5,11 +5,15 @@ Please see the Verilator manual for 200+ additional contributors. Thanks to all.

 Adrien Le Masle
 Ahmed El-Mahmoudy
+Aleksander Kiryk
 Alex Chadwick
 Àlex Torregrosa
+Aliaksei Chapyzhenka
 Ameya Vikram Singh
 Andreas Kuster
+Arkadiusz Kozdra
 Chris Randall
+Chuxuan Wang
 Conor McCullough
 Dan Petrisko
 Daniel Bates
@@ -17,6 +21,7 @@ David Horton
 David Metz
 David Stanford
 David Turner
+Drew Ranck
 Drew Taussig
 Driss Hafdi
 Edgar E. Iglesias
@@ -28,18 +33,23 @@ Geza Lore
 Gianfranco Costamagna
 Glen Gibb
 Graham Rushton
+Guokai Chen
+Gustav Svensk
 Harald Heckmann
 Howard Su
 Huang Rui
+Huanghuang Zhou
 HungMingWu
 HyungKi Jeong
 Iru Cai
 Ivan Vnučec
 Iztok Jeras
+Jake Merdich
 James Hanlon
 James Hutchinson
 James Pallister
 Jamey Hicks
+Jamie Iles
 Jan Van Winkel
 Jean Berniolles
 Jeremy Bennett
@@ -50,31 +60,38 @@ Josh Redford
 Julie Schwartz
 Julien Margetts
 Kaleb Barrett
+Kamil Rakoczy
 Kanad Kanhere
 Keith Colbert
 Kevin Kiningham
 Krzysztof Bieganski
 Kuba Ober
+Larry Doolittle
 Ludwig Rogiers
 Lukasz Dalek
 Maarten De Braekeleer
 Maciej Sobkowski
 Marco Widmer
+Mariusz Glebocki
 Markus Krause
 Marlon James
 Marshal Qiao
 Martin Schmidt
+Martin Stadler
 Matthew Ballance
 Michael Killough
 Michaël Lefebvre
 Mike Popoloski
 Miodrag Milanović
+Mladen Slijepcevic
 Morten Borup Petersen
+Mostafa Gamal
 Nandu Raj
 Nathan Kohagen
 Nathan Myers
 Patrick Stewart
 Paul Wright
+Pawel Sagan
 Peter Horvath
 Peter Monsson
 Philipp Wagner
@@ -83,8 +100,10 @@ Pieter Kapsenberg
 Piotr Binkowski
 Qingyao Sun
 Rafal Kapuscik
+Raynard Qiao
 Richard Myers
 Rupert Swarbrick
+Ryszard Rozak
 Samuel Riedel
 Sean Cross
 Sebastien Van Cauwenberghe
@@ -101,12 +120,17 @@ Tomasz Gorochowik
 Tymoteusz Blazejczyk
 Udi Finkelstein
 Unai Martinez-Corral
+Varun Koyyalagunta
 Vassilis Papaefstathiou
 Veripool API Bot
 Victor Besyakov
+William D. Jones
 Wilson Snyder
+Xi Zhang
+Yoda Lee
 Yossi Nivin
 Yuri Victorovich
 Yutetsu TAKATSUKASA
+Yu-Sheng Lin
 Yves Mathieu
 Zhanglei Wang
@@ -35,6 +35,7 @@ default:
 # Intermediate rules

 vl-extract: ../bin/verilator ../Changes
+	ln -sf ../spelling.txt guide/spelling.txt
 	mkdir -p _build/gen
 	$(PYTHON3) bin/vl_sphinx_extract ../bin/verilator
 	sed 's/`/\&96;/g' < ../Changes > _build/gen/Changes
@@ -77,6 +78,7 @@ clean mostlyclean distclean maintainer-clean::
 	rm -f *.pg *.pgs *.toc *.tp *.tps *.vr *.vrs *.idx
 	rm -f *.ev *.evs *.ov *.ovs *.cv *.cvs *.ma *.mas
 	rm -f *.tex
+	rm -f guide/spelling.txt

 distclean maintainer-clean::
 	rm -f *.info* *.1 *.html *.pdf $(INFOS)
@@ -13,6 +13,7 @@ from datetime import datetime
 import os
 import re
 import sys
+
 sys.path.insert(0, os.path.abspath('./_ext'))

 import sphinx_rtd_theme  # pylint: disable=wrong-import-position,
@@ -86,58 +86,17 @@ Connecting to C++
 In C++ output mode (:vlopt:`--cc`), the Verilator generated model class is a
 simple C++ class.  The user must write a C++ wrapper and main loop for the
 simulation, which instantiates the model class, and link with the Verilated
-model.  Here is a simple example:
+model.

-.. code-block:: C++
+Refer to ``examples/make_tracing_c`` in the distribution for a detailed
+commented example.

-         #include <verilated.h>          // Defines common routines
-         #include <iostream>             // Need std::cout
-         #include "Vtop.h"               // From Verilating "top.v"
+Top level IO signals are read and written as members of the model.  You
+call the model's :code:`eval()` method to evaluate the model.  When the
+simulation is complete call the model's :code:`final()` method to execute
+any SystemVerilog final blocks, and complete any assertions. See
+:ref:`Evaluation Loop`.

-         Vtop *top;                      // Instantiation of model
-
-         vluint64_t main_time = 0;       // Current simulation time
-         // This is a 64-bit integer to reduce wrap over issues and
-         // allow modulus.  This is in units of the timeprecision
-         // used in Verilog (or from --timescale-override)
-
-         double sc_time_stamp() {        // Called by $time in Verilog
-             return main_time;           // converts to double, to match
-                                         // what SystemC does
-         }
-
-         int main(int argc, char** argv) {
-             Verilated::commandArgs(argc, argv);   // Remember args
-
-             top = new Vtop;             // Create model
-
-             top->reset_l = 0;           // Set some inputs
-
-             while (!Verilated::gotFinish()) {
-                 if (main_time > 10) {
-                     top->reset_l = 1;   // Deassert reset
-                 }
-                 if ((main_time % 10) == 1) {
-                     top->clk = 1;       // Toggle clock
-                 }
-                 if ((main_time % 10) == 6) {
-                     top->clk = 0;
-                 }
-                 top->eval();            // Evaluate model
-                 cout << top->out << endl;       // Read a output
-                 main_time++;            // Time passes...
-             }
-
-             top->final();               // Done simulating
-             //    // (Though this example doesn't get here)
-             delete top;
-         }
-
-
-Note top level IO signals are read and written as members of the model.  You
-call the :code:`eval()` method to evaluate the model.  When the simulation is
-complete call the :code:`final()` method to execute any SystemVerilog final
-blocks, and complete any assertions. See :ref:`Evaluation Loop`.


 Connecting to SystemC
@@ -150,7 +109,7 @@ netlist as an instantiation.
 The SC_MODULE gets the same pinout as the Verilog module, with the
 following type conversions: Pins of a single bit become bool.  Pins 2-32
 bits wide become uint32_t's.  Pins 33-64 bits wide become sc_bv's or
-vluint64_t's depending on the :vlopt:`--no-pins64` option.  Wider pins
+uint64_t's depending on the :vlopt:`--no-pins64` option.  Wider pins
 become sc_bv's.  (Uints simulate the fastest so are used where possible.)

 Model internals, including lower level sub-modules are not pure SystemC
@@ -200,7 +159,7 @@ DPI System Task/Functions
 -------------------------

 Verilator extends the DPI format to allow using the same scheme to
-efficiently add system functions.  Simply use a dollar-sign prefixed system
+efficiently add system functions.  Use a dollar-sign prefixed system
 function name for the import, but note it must be escaped.

 .. code-block:: sv
@@ -257,7 +216,9 @@ with respect to that top level module, then the scope could be set with

     #include "svdpi.h"
     ...
-     svSetScope(svGetScopeFromName("TOP.dut"));
+     const svScope scope = svGetScopeFromName("TOP.dut");
+     assert(scope);  // Check for nullptr if scope not found
+     svSetScope(scope);

 (Remember that Verilator adds a "TOP" to the top of the module hierarchy.)

@@ -422,12 +383,12 @@ accesses the above signal "readme" would be:

 .. code-block:: bash

-     cat >sim_main.cpp <<'<<EOF'
+     cat >sim_main.cpp <<'EOF'
       #include "Vour.h"
       #include "verilated.h"
       #include "verilated_vpi.h"  // Required to get definitions

-       vluint64_t main_time = 0;   // See comments in first example
+       uint64_t main_time = 0;   // See comments in first example
       double sc_time_stamp() { return main_time; }

       void read_and_check() {
@@ -444,14 +405,15 @@ accesses the above signal "readme" would be:

       int main(int argc, char** argv, char** env) {
           Verilated::commandArgs(argc, argv);
-           Vour* top = new Vour;
-           Verilated::internalsDump();  // See scopes to help debug
-           while (!Verilated::gotFinish()) {
+           const std::unique_ptr<VerilatedContext> contextp{new VerilatedContext};
+           const std::unique_ptr<Vour> top{new Vour{contextp.get()}};
+
+           contextp->internalsDump();  // See scopes to help debug
+           while (!contextp->gotFinish()) {
               top->eval();
               VerilatedVpi::callValueCbs();  // For signal callbacks
               read_and_check();
           }
-           delete top;
           return 0;
       }
     EOF
@@ -506,7 +468,7 @@ structure.  If a ``VerilatedContext`` is not created prior to creating a
 model, a default global one is created automatically.

 The ``Verilated::`` methods, including the ``Verilated::commandArgs`` call
-shown above, simply call VerilatedContext methods using the default global
+shown above, call VerilatedContext methods using the default global
 VerilatedContext.  (Technically they operate on the last one used by a
 given thread.)  If you are using multiple simulation contexts you should
 not use the Verilated:: methods, and instead always use VerilatedContext
@@ -23,14 +23,14 @@ Contributors
 Many people have provided ideas and other assistance with Verilator.

 Verilator is receiving major development support from the `CHIPS Alliance
-<https://chipsalliance.org>`_.
+<https://chipsalliance.org>`_ and `Shunyao CAD <https://shunyaocad.com>`_.

 Previous major corporate sponsors of Verilator, by providing significant
 contributions of time or funds included include: Atmel Corporation, Cavium
 Inc., Compaq Corporation, Digital Equipment Corporation, Embecosm Ltd.,
 Hicamp Systems, Intel Corporation, Mindspeed Technologies Inc., MicroTune
 Inc., picoChip Designs Ltd., Sun Microsystems Inc., Nauticus Networks Inc.,
-and SiCortex Inc.
+SiCortex Inc, and Shunyao CAD.

 The people who have contributed major functionality are: Byron Bradley,
 Jeremy Bennett, Lane Brooks, John Coiner, Duane Galbi, Geza Lore, Todd
@@ -16,14 +16,22 @@ Verilated_heavy.h
  "verilated.h". Verilated_heavy.h is planned for removal no sooner than
  July 2022.

-Configuration File -msg
-  The :vlopt:`lint_off` "-msg" option has been replaced with the "-rule"
-  option.  "-msg" is planned for removal no sooner than January 2021.
-
-XML locations
-  The XML "fl" attribute has been replaced with the "loc" attribute.  "fl"
-  is planned for removal no sooner than January 2021.
-
 Option `--cdc`
  The experimental `--cdc` option is believed to be generally unused and is
-  planned for removeal no sooner than January 2023.
+  planned for removal no sooner than January 2023.
+
+Option `-O<letter>`
+  The debug `-O<letter>` options have been replaced with
+  `-fno-<optimization>` debug options to match GCC. The old options are
+  planned for removal no sooner than June 2023.
+
+Option `--prof-threads`
+  The `--prof-threads` option has been superseded by the `--prof-exec` and
+  `--prof-pgo` options and is planned for removal no sooner than April 2023.
+
+Verilated model options `+verilator+prof+threads+*`
+  The `+verilator+prof+threads+start`, `+verilator+prof+threads+window` and
+  `+verilator+prof+threads+file` options have been superseded by the
+  `+verilator+prof+exec+start`, `+verilator+prof+exec+window` and
+  `+verilator+prof+exec+file` options respectively and are planned for removal
+  no sooner than April 2023.
@@ -8,7 +8,7 @@ Simulation Runtime Arguments

 The following are the arguments that may be passed to a Verilated
 executable, provided that executable calls
-:code:`Verilated::commandArgs()`.
+:code:`VerilatedContext*->commandArgs(argc, argv)`.

 All simulation runtime arguments begin with "+verilator", so that the
 user's executable may skip over all "+verilator" arguments when parsing its
@@ -38,33 +38,45 @@ Summary:

   Display help and exit.

-.. option:: +verilator+prof+threads+file+<filename>
+.. option:: +verilator+prof+exec+file+<filename>

-   When a model was Verilated using :vlopt:`--prof-threads`, sets the
+   When a model was Verilated using :vlopt:`--prof-exec`, sets the
   simulation runtime filename to dump to.  Defaults to
-   :file:`profile_threads.dat`.
+   :file:`profile_exec.dat`.

-.. option:: +verilator+prof+threads+start+<value>
+.. option:: +verilator+prof+exec+start+<value>

-   When a model was Verilated using :vlopt:`--prof-threads`, the simulation
+   When a model was Verilated using :vlopt:`--prof-exec`, the simulation
   runtime will wait until $time is at this value (expressed in units of
   the time precision), then start the profiling warmup, then
   capturing. Generally this should be set to some time that is well within
   the normal operation of the simulation, i.e. outside of reset. If 0, the
   dump is disabled. Defaults to 1.

-.. option:: +verilator+prof+threads+window+<value>
+.. option:: +verilator+prof+exec+window+<value>

-   When a model was Verilated using :vlopt:`--prof-threads`, after $time
-   reaches :vlopt:`+verilator+prof+threads+start+\<value\>`, Verilator will
+   When a model was Verilated using :vlopt:`--prof-exec`, after $time
+   reaches :vlopt:`+verilator+prof+exec+start+\<value\>`, Verilator will
   warm up the profiling for this number of eval() calls, then will capture
   the profiling of this number of eval() calls.  Defaults to 2, which
   makes sense for a single-clock-domain module where it's typical to want
   to capture one posedge eval() and one negedge eval().

+.. option:: +verilator+prof+threads+file+<filename>
+
+   Deprecated. Alias for :vlopt:`+verilator+prof+exec+file+\<filename\>`
+
+.. option:: +verilator+prof+threads+start+<value>
+
+   Deprecated. Alias for :vlopt:`+verilator+prof+exec+start+\<value\>`
+
+.. option:: +verilator+prof+threads+window+<value>
+
+   Deprecated. Alias for :vlopt:`+verilator+prof+exec+window+\<filename\>`
+
 .. option:: +verilator+prof+vlt+file+<filename>

-   When a model was Verilated using :vlopt:`--prof-threads`, sets the
+   When a model was Verilated using :vlopt:`--prof-pgo`, sets the
   profile-guided optimization data runtime filename to dump to.  Defaults
   to :file:`profile.vlt`.

@@ -84,7 +96,7 @@ Summary:
 .. option:: +verilator+noassert

   Disable assert checking per runtime argument. This is the same as
-   calling :code:`Verilated::assertOn(false)` in the model.
+   calling :code:`VerilatedContext*->assertOn(false)` in the model.

 .. option:: +verilator+V

@@ -99,10 +99,10 @@ Summary:
 .. option:: --bbox-sys

   Black box any unknown $system task or function calls.  System tasks will
-   simply become no-operations, and system functions will be replaced with
-   unsized zero.  Arguments to such functions will be parsed, but not
-   otherwise checked.  This prevents errors when linting in the presence of
-   company specific PLI calls.
+   become no-operations, and system functions will be replaced with unsized
+   zero.  Arguments to such functions will be parsed, but not otherwise
+   checked.  This prevents errors when linting in the presence of company
+   specific PLI calls.

   Using this argument will likely cause incorrect simulation.

@@ -115,13 +115,6 @@ Summary:

   Using this argument will likely cause incorrect simulation.

-.. option:: --bin <filename>
-
-   Rarely needed.  Override the default filename for Verilator itself.
-   When a dependency (.d) file is created, this filename will become a
-   source dependency, such that a change in this binary will have make
-   rebuild the output files.
-
 .. option:: --build

   After generating the SystemC/C++ code, Verilator will invoke the
@@ -129,15 +122,23 @@ Summary:
   is also used). Verilator manages the build itself, and for this --build
   requires GNU Make to be available on the platform.

-.. option:: -CFLAGS <flags>
+.. option:: --build-dep-bin <filename>

-   Add specified C compiler argument to the generated makefiles. For
-   multiple flags either pass them as a single argument with space
-   separators quoted in the shell (:command:`-CFLAGS "-a -b"`), or use
-   multiple -CFLAGS options (:command:`-CFLAGS -a -CFLAGS -b`).
+   Rarely needed.  When a dependency (.d) file is created, this filename
+   will become a source dependency, such that a change in this binary will
+   have make rebuild the output files.  Defaults to the full path to the
+   Verilator binary.

-   When make is run on the generated makefile these will be passed to the
-   C++ compiler (g++/clang++/msvc++).
+   This option was named `--bin` prior to version 4.228.
+
+.. option:: --build-jobs [<value>]
+
+   Specify the level of parallelism for :vlopt:`--build`. If zero, uses the
+   number of threads in the current hardware. Otherwise, the <value> must
+   be a positive integer specifying the maximum number of parallel build
+   jobs.
+
+   See also :vlopt:`-j`.

 .. option:: --cc

@@ -156,6 +157,16 @@ Summary:
   have interest in adding more traditional CDC checks, please contact the
   authors.

+.. option:: -CFLAGS <flags>
+
+   Add specified C compiler argument to the generated makefiles. For
+   multiple flags either pass them as a single argument with space
+   separators quoted in the shell (:command:`-CFLAGS "-a -b"`), or use
+   multiple -CFLAGS options (:command:`-CFLAGS -a -CFLAGS -b`).
+
+   When make is run on the generated makefile these will be passed to the
+   C++ compiler (g++/clang++/msvc++).
+
 .. option:: --clk <signal-name>

   With :vlopt:`--clk`, the specified signal-name is taken as a root clock
@@ -179,6 +190,11 @@ Summary:
   remove it from the combinatorial logic reevaluation checking code. This
   may greatly improve performance.

+.. option:: --no-clk <signal-name>
+
+   Prevent the specified signal from being marked as clock. See
+   :vlopt:`--clk`.
+
 .. option:: --compiler <compiler-name>

   Enables workarounds for the specified C++ compiler (list below).
@@ -250,8 +266,8 @@ Summary:
     generally is a less-optimized binary with symbols present (so GDB can be used on it).
   * Enable debugging messages (equivalent to :vlopt:`--debugi 3 <--debugi>`).
   * Enable internal assertions (equivalent to :vlopt:`--debug-check`).
-   * Enable intermediate form dump files (equivalent to :vlopt:`--dump-treei 3
-     <--dump-treei>`).
+   * Enable intermediate form dump files (equivalent to :vlopt:`--dumpi-tree 3
+     <--dumpi-tree>`).
   * Leak to make node numbers unique (equivalent to :vlopt:`--debug-leak
     <--no-debug-leak>`.
   * Call abort() instead of exit() if there are any errors (so GDB can see
@@ -288,6 +304,13 @@ Summary:
   <--debugi>`). Higher levels produce more detailed messages.  See
   :vlopt:`--debug` for other implications of enabling debug.

+.. option:: --no-decoration
+
+   When creating output Verilated code, minimize comments, white space,
+   symbol names and other decorative items, at the cost of greatly reduced
+   readability. This may assist C++ compile times. This will not typically
+   change the ultimate model's performance, but may in some cases.
+
 .. option:: --default-language <value>

   Select the language to be used by default when first processing each
@@ -335,26 +358,21 @@ Summary:

       touch foo.v ; verilator -E --dump-defines foo.v

+.. option:: --dump-graph
+
+   Rarely needed.  Enable dumping V3Graph .dot debug files with dumping
+   level 3. Before Verilator 4.228, :vlopt:`--dump-tree` used
+   to include this option.
+
 .. option:: --dump-tree

-   Rarely needed.  Enable writing .tree debug files with dumping level 3,
+   Rarely needed.  Enable dumping Ast .tree debug files with dumping level 3,
   which dumps the standard critical stages.  For details on the format see
   the Verilator Internals manual.  :vlopt:`--dump-tree` is enabled
   automatically with :vlopt:`--debug`, so :vlopt:`--debug --no-dump-tree
   <--dump-tree>` may be useful if the dump files are large and not
   desired.

-.. option:: --dump-treei <level>
-
-.. option:: --dump-treei-<srcfile> <level>
-
-   Rarely needed - for developer use.  Set internal tree dumping level
-   globally to a specific dumping level or set the specified Verilator
-   source file to the specified tree dumping level (e.g.
-   :vlopt:`--dump-treei-V3Order 9 <--dump-treei>`).  Level 0 disables dumps
-   and is equivalent to :vlopt:`--no-dump-tree <--dump-tree>`.  Level 9
-   enables dumping of every stage.
-
 .. option:: --dump-tree-addrids

   Rarely needed - for developer use.  Replace AST node addresses with
@@ -364,6 +382,28 @@ Summary:
   by a newly allocated node after a node with the same address has been
   dumped then freed.

+.. option:: --dump-<srcfile>
+
+   Rarely needed - for developer use. Enable all dumping in the given
+   source file at level 3.
+
+.. option:: --dumpi-graph <level>
+
+   Rarely needed - for developer use.  Set internal V3Graph dumping level
+   globally to the specified value.
+
+.. option:: --dumpi-tree <level>
+
+   Rarely needed - for developer use.  Set internal Ast dumping level
+   globally to the specified value.
+
+.. option:: --dumpi-<srcfile> <level>
+
+   Rarely needed - for developer use. Set the dumping level in the
+   specified Verilator source file to the specified value (e.g.
+   :vlopt:`--dumpi-V3Order 9`).  Level 0 disables dumps and is equivalent
+   to :vlopt:`--no-dump-<srcfile>`.  Level 9 enables dumping of everything.
+
 .. option:: -E

   Preprocess the source code, but do not compile, similar to C++
@@ -431,6 +471,78 @@ Summary:
   flattening large designs may require significant CPU time, memory and
   storage.

+.. option:: -fno-acyc-simp
+
+.. option:: -fno-assemble
+
+.. option:: -fno-case
+
+.. option:: -fno-combine
+
+.. option:: -fno-const
+
+.. option:: -fno-const-bit-op-tree
+
+.. option:: -fno-dedup
+
+.. option:: -fno-expand
+
+.. option:: -fno-gate
+
+.. option:: -fno-inline
+
+.. option:: -fno-life
+
+.. option:: -fno-life-post
+
+.. option:: -fno-localize
+
+.. option:: -fno-merge-cond
+
+.. option:: -fno-merge-cond-motion
+
+.. option:: -fno-merge-const-pool
+
+.. option:: -fno-reloop
+
+.. option:: -fno-reorder
+
+.. option:: -fno-split
+
+.. option:: -fno-subst
+
+.. option:: -fno-subst-const
+
+.. option:: -fno-table
+
+   Rarely needed. Disables one of the internal optimization steps. These
+   are typically used only when recommended by a maintainer to help debug
+   or work around an issue.
+
+.. option:: -future0 <option>
+
+   Rarely needed.  Suppress an unknown Verilator option for an option that
+   takes no additional arguments.  This is used to allow scripts written
+   with pragmas for a later version of Verilator to run under a older
+   version.  e.g. :code:`-future0 option --option` would on older versions
+   that do not understand :code:`--option` or :code:`+option` suppress what
+   would otherwise be an invalid option error, and on newer versions that
+   implement :code:`--option`, :code:`-future0 option --option` would have
+   the :code:`-future0 option` ignored and the :code:`--option` would
+   function appropriately.
+
+.. option:: -future1 <option>
+
+   Rarely needed.  Suppress an unknown Verilator option for an option that
+   takes an additional argument.  This is used to allow scripts written
+   with pragmas for a later version of Verilator to run under a older
+   version.  e.g. :code:`-future1 option --option arg` would on older
+   versions that do not understand :code:`--option arg` or :code:`+option
+   arg` suppress what would otherwise be an invalid option error, and on
+   newer versions that implement :code:`--option arg`, :code:`-future1
+   option --option arg` would have the :code:`-future1 option` ignored and
+   the :code:`--option arg` would function appropriately.
+
 .. option:: -G<name>=<value>

   Overwrites the given parameter of the toplevel module. The value is
@@ -531,26 +643,10 @@ Summary:

 .. option:: -j [<value>]

-   Specify the level of parallelism for :vlopt:`--build`. The <value> must
-   be a positive integer specifying the maximum number of parallel build
-   jobs, or can be omitted. When <value> is omitted, the build will not try
-   to limit the number of parallel build jobs but attempt to execute all
-   independent build steps in parallel.
-
-.. option:: -LDFLAGS <flags>
-
-   Add specified C linker arguments to the generated makefiles.  For multiple
-   flags either pass them as a single argument with space separators quoted
-   in the shell (``-LDFLAGS "-a -b"``), or use multiple -LDFLAGS arguments
-   (``-LDFLAGS -a -LDFLAGS -b``).
-
-   When make is run on the generated makefile these will be passed to the
-   C++ linker (ld) **after** the primary file being linked.  This flag is
-   called :vlopt:`-LDFLAGS` as that's the traditional name in simulators;
-   it's would have been better called LDLIBS as that's the Makefile
-   variable it controls.  (In Make, LDFLAGS is before the first object,
-   LDLIBS after.  -L libraries need to be in the Make variable LDLIBS, not
-   LDFLAGS.)
+   Specify the level of parallelism for :vlopt:`--build` if
+   :vlopt:`--build-jobs` isn't provided. If zero, uses the number of threads
+   in the current hardware. Otherwise, the <value> must be a positive
+   integer specifying the maximum number of parallel build jobs.

 .. option:: --l2-name <value>

@@ -568,12 +664,20 @@ Summary:
   A synonym for :vlopt:`--default-language`, for compatibility with other
   tools and earlier versions of Verilator.

-.. option:: +libext+<ext>[+<ext>][...]
+.. option:: -LDFLAGS <flags>

-   Specify the extensions that should be used for finding modules.  If for
-   example module "my" is referenced, look in :file:`my.<ext>`.  Note
-   "+libext+" is fairly standard across Verilog tools.  Defaults to
-   ".v+.sv".
+   Add specified C linker arguments to the generated makefiles.  For multiple
+   flags either pass them as a single argument with space separators quoted
+   in the shell (``-LDFLAGS "-a -b"``), or use multiple -LDFLAGS arguments
+   (``-LDFLAGS -a -LDFLAGS -b``).
+
+   When make is run on the generated makefile these will be passed to the
+   C++ linker (ld) **after** the primary file being linked.  This flag is
+   called :vlopt:`-LDFLAGS` as that's the traditional name in simulators;
+   it's would have been better called LDLIBS as that's the Makefile
+   variable it controls.  (In Make, LDFLAGS is before the first object,
+   LDLIBS after.  -L libraries need to be in the Make variable LDLIBS, not
+   LDFLAGS.)

 .. option:: --lib-create <name>

@@ -592,6 +696,13 @@ Summary:

   See also :vlopt:`--protect-lib`.

+.. option:: +libext+<ext>[+<ext>][...]
+
+   Specify the extensions that should be used for finding modules.  If for
+   example module "my" is referenced, look in :file:`my.<ext>`.  Note
+   "+libext+" is fairly standard across Verilog tools.  Defaults to
+   ".v+.sv".
+
 .. option:: --lint-only

   Check the files for lint violations only, do not create any other
@@ -625,22 +736,20 @@ Summary:
   (e.g. ``-MAKEFLAGS -l -MAKEFLAGS -k``). Use of this option should not be
   required for simple builds using the host toolchain.

+.. option:: --main
+
+   Generates a top-level C++ main() file that supports parsing arguments,
+   but does not drive any inputs.  This is sufficient to use for top-level
+   SystemVerilog designs that has no inputs, and does not need the C++ to
+   do any time advancement.
+
+   Implies :vlopt:`--cc` if no other output mode was provided.
+
 .. option:: --max-num-width <value>

   Set the maximum number literal width (e.g. in 1024'd22 this it the
   1024).  Defaults to 64K.

-.. option:: --MMD =item --no-MMD
-
-   Enable/disable creation of .d dependency files, used for make dependency
-   detection, similar to gcc -MMD option.  By default this option is
-   enabled for :vlopt:`--cc` or :vlopt:`--sc` modes.
-
-.. option:: --MP
-
-   When creating .d dependency files with :vlopt:`--MMD` option, make phony
-   targets.  Similar to :command:`gcc -MP` option.
-
 .. option:: --Mdir <directory>

   Specifies the name of the Make object directory.  All generated files
@@ -648,40 +757,23 @@ Summary:
   The directory is created if it does not exist and the parent directories
   exist; otherwise manually create the Mdir before calling Verilator.

-.. option:: --no-merge-const-pool
+.. option:: --MMD

-   Rarely needed.  In order to minimize cache footprint, values of different
-   data type, that are yet emitted identically in C++ are merged in the
-   constant pool.  This option disables this and causes every constant pool
-   entry with a distinct data type to be emitted separately.
+.. option:: --no-MMD
+
+   Enable/disable creation of .d dependency files, used for make dependency
+   detection, similar to gcc -MMD option.  By default this option is
+   enabled for :vlopt:`--cc` or :vlopt:`--sc` modes.

 .. option:: --mod-prefix <topname>

   Specifies the name to prepend to all lower level classes.  Defaults to
   the same as :vlopt:`--prefix`.

-.. option:: --no-clk <signal-name>
+.. option:: --MP

-   Prevent the specified signal from being marked as clock. See
-   :vlopt:`--clk`.
-
-.. option:: --no-decoration
-
-   When creating output Verilated code, minimize comments, white space,
-   symbol names and other decorative items, at the cost of greatly reduced
-   readability. This may assist C++ compile times. This will not typically
-   change the ultimate model's performance, but may in some cases.
-
-.. option:: --no-pins64
-
-   Backward compatible alias for :vlopt:`--pins-bv 33 <--pins-bv>`.
-
-.. option:: --no-skip-identical =item --skip-identical
-
-   Rarely needed.  Disables or enables skipping execution of Verilator if
-   all source files are identical, and all output files exist with newer
-   dates.  By default this option is enabled for :vlopt:`--cc` or
-   :vlopt:`--sc` modes only.
+   When creating .d dependency files with :vlopt:`--MMD` option, make phony
+   targets.  Similar to :command:`gcc -MP` option.

 .. option:: +notimingchecks

@@ -703,9 +795,9 @@ Summary:

   Rarely needed.  Enables or disables a specific optimizations, with the
   optimization selected based on the letter passed.  A lowercase letter
-   disables an optimization, an upper case letter enables it.  This is
-   intended for debugging use only; see the source code for
-   version-dependent mappings of optimizations to -O letters.
+   disables an optimization, an upper case letter enables it.  This option
+   is deprecated and the various `-f<optimization>` arguments should be
+   used instead.

 .. option:: -o <executable>

@@ -760,15 +852,10 @@ Summary:
   With :vlopt:`-E`, disable generation of :code:`&96;line` markers and
   blank lines, similar to :command:`gcc -P`.

-.. option:: --pins64
-
-   Backward compatible alias for :vlopt:`--pins-bv 65 <--pins-bv>`.  Note
-   that's a 65, not a 64.
-
 .. option:: --pins-bv <width>

   Specifies SystemC inputs/outputs of greater than or equal to <width>
-   bits wide should use sc_bv's instead of uint32/vluint64_t's.  The
+   bits wide should use sc_bv's instead of uint32/uint64_t's.  The
   default is "--pins-bv 65", and the value must be less than or equal
   to 65.  Versions before Verilator 3.671 defaulted to "--pins-bv 33".
   The more sc_bv is used, the worse for performance.  Use the
@@ -797,6 +884,15 @@ Summary:
   of uint32_t.  Likewise pins of width 9-16 will use uint16_t instead of
   uint32_t.

+.. option:: --pins64
+
+   Backward compatible alias for :vlopt:`--pins-bv 65 <--pins-bv>`.  Note
+   that's a 65, not a 64.
+
+.. option:: --no-pins64
+
+   Backward compatible alias for :vlopt:`--pins-bv 33 <--pins-bv>`.
+
 .. option:: --pipe-filter <command>

   Rarely needed.  Verilator will spawn the specified command as a
@@ -826,6 +922,11 @@ Summary:
   prepended to the name of the :vlopt:`--top` option, or V prepended to
   the first Verilog filename passed on the command line.

+.. option:: --private
+
+   Opposite of :vlopt:`--public`.  Is the default; this option exists for
+   backwards compatibility.
+
 .. option:: --prof-c

   When compiling the C++ code, enable the compiler's profiling flag
@@ -845,27 +946,19 @@ Summary:

   Using :vlopt:`--prof-cfuncs` also enables :vlopt:`--prof-c`.

+.. option:: --prof-exec
+
+   Enable collection of execution trace, that can be converted into a gantt
+   chart with verilator_gantt See :ref:`Execution Profiling`.
+
+.. option:: --prof-pgo
+
+   Enable collection of profiling data for profile guided Verilation. Currently
+   this is only useful with :vlopt:`--threads`. See :ref:`Thread PGO`.
+
 .. option:: --prof-threads

-   Enable gantt chart data collection for threaded builds. See :ref:`Thread
-   Profiling` and :ref:`Thread PGO`.
-
-.. option:: --protect-key <key>
-
-   Specifies the private key for :vlopt:`--protect-ids`. For best security
-   this key should be 16 or more random bytes, a reasonable secure choice
-   is the output of :command:`verilator --generate-key` . Typically, a key
-   would be created by the user once for a given protected design library,
-   then every Verilator run for subsequent versions of that library would
-   be passed the same :vlopt:`--protect-key`. Thus, if the input Verilog is
-   similar between library versions (Verilator runs), the Verilated code
-   will likewise be mostly similar.
-
-   If :vlopt:`--protect-key` is not specified and a key is needed,
-   Verilator will generate a new key for every Verilator run. As the key is
-   not saved, this is best for security, but means every Verilator run will
-   give vastly different output even for identical input, perhaps harming
-   compile times (and certainly thrashing any "ccache").
+   Deprecated. Same as --prof-exec and --prof-pgo together.

 .. option:: --protect-ids

@@ -884,9 +977,26 @@ Summary:

   Using DPI imports/exports is allowed and generally relatively safe in
   terms of information disclosed, which is limited to the DPI function
-   prototyptes.  Use of the VPI is not recommended as many design details
+   prototypes.  Use of the VPI is not recommended as many design details
   may be exposed, and an INSECURE warning will be issued.

+.. option:: --protect-key <key>
+
+   Specifies the private key for :vlopt:`--protect-ids`. For best security
+   this key should be 16 or more random bytes, a reasonable secure choice
+   is the output of :command:`verilator --generate-key` . Typically, a key
+   would be created by the user once for a given protected design library,
+   then every Verilator run for subsequent versions of that library would
+   be passed the same :vlopt:`--protect-key`. Thus, if the input Verilog is
+   similar between library versions (Verilator runs), the Verilated code
+   will likewise be mostly similar.
+
+   If :vlopt:`--protect-key` is not specified and a key is needed,
+   Verilator will generate a new key for every Verilator run. As the key is
+   not saved, this is best for security, but means every Verilator run will
+   give vastly different output even for identical input, perhaps harming
+   compile times (and certainly thrashing any "ccache").
+
 .. option:: --protect-lib <name>

   Produces a DPI library similar to :vlopt:`--lib-create`, but hides
@@ -898,11 +1008,6 @@ Summary:
   in the distribution for a demonstration of how to build and use the DPI
   library.

-.. option:: --private
-
-   Opposite of :vlopt:`--public`.  Is the default; this option exists for
-   backwards compatibility.
-
 .. option:: --public

   This is only for historical debug use.  Using it may result in
@@ -995,6 +1100,15 @@ Summary:

   Specifies SystemC output mode; see also :vlopt:`--cc` option.

+.. option:: --skip-identical
+
+.. option:: --no-skip-identical
+
+   Rarely needed.  Disables or enables skipping execution of Verilator if
+   all source files are identical, and all output files exist with newer
+   dates.  By default this option is enabled for :vlopt:`--cc` or
+   :vlopt:`--sc` modes only.
+
 .. option:: --stats

   Creates a dump file with statistics on the design in
@@ -1032,7 +1146,8 @@ Summary:
   is not thread safe. With "--threads 1", the generated model is single
   threaded but may run in a multithreaded environment. With "--threads N",
   where N >= 2, the model is generated to run multithreaded on up to N
-   threads. See :ref:`Multithreading`.
+   threads. See :ref:`Multithreading`. This option also applies to
+   :vlopt:`--trace` (but not :vlopt:`--trace-fst`).

 .. option:: --threads-dpi all

@@ -1110,7 +1225,8 @@ Summary:
   Having tracing compiled in may result in some small performance losses,
   even when tracing is not turned on during model execution.

-   See also :vlopt:`--trace-threads` option.
+   When using :vlopt:`--threads`, VCD tracing is parallelized, using the
+   same number of threads as passed to :vlopt:`--threads`.

 .. option:: --trace-coverage

@@ -1164,12 +1280,12 @@ Summary:
 .. option:: --trace-threads *threads*

   Enable waveform tracing using separate threads. This is typically faster
-   in simulation runtime but uses more total compute. This option is
-   independent of, and works with, both :vlopt:`--trace` and
-   :vlopt:`--trace-fst`.  Different trace formats can take advantage of
-   more trace threads to varying degrees. Currently VCD tracing can utilize
-   at most "--trace-threads 1", and FST tracing can utilize at most
-   "--trace-threads 2". This overrides :vlopt:`--no-threads` .
+   in simulation runtime but uses more total compute. This option only
+   applies to :vlopt:`--trace-fst`. FST tracing can utilize at most
+   "--trace-threads 2". This overrides :vlopt:`--no-threads`.
+
+   This option is accepted, but has absolutely no effect with
+   :vlopt:`--trace`, which respects :vlopt:`--threads` instead.

 .. option:: --trace-underscore

@@ -1514,7 +1630,7 @@ The grammar of configuration commands is as follows:
 .. option:: no_clocker -module "<modulename>" [-function "<funcname>"] -var "<signame>"

   Indicates that the signal is used as clock or not. This information is
-   used by Verilator to mark the signal and any derrived signals as
+   used by Verilator to mark the signal and any derived signals as
   clocker.  See :vlopt:`--clk`.

   Same as :option:`/*verilator&32;clocker*/` metacomment.
@@ -1638,7 +1754,7 @@ The grammar of configuration commands is as follows:
 .. option:: sc_bv -module "<modulename>" [-function "<funcname>"] -var "<signame>"

   Sets the port to be of :code:`sc_bv<{width}>` type, instead of bool,
-   vluint32_t or vluint64_t.  Same as :option:`/*verilator&32;sc_bv*/`
+   uint32_t or uint64_t.  Same as :option:`/*verilator&32;sc_bv*/`
   metacomment.

 .. option:: sformat [-module "<modulename>"] [-task "<taskname>"] -var "<signame>"
@@ -1667,9 +1783,28 @@ The grammar of configuration commands is as follows:

 .. option:: tracing_off [-file "<filename>" [-lines <line> [ - <line> ]]]

-   Enable/disable waveform tracing for all future signals declared in the
-   specified filename (or wildcard with '\*' or '?', or all files if
-   omitted) and range of line numbers (or all lines if omitted).
+.. option:: tracing_on  [-scope "<scopename>" [-levels <levels> ]]

-   For tracing_off, instances below any module in the files/ranges
-   specified will also not be traced.
+.. option:: tracing_off [-scope "<scopename>" [-levels <levels> ]]
+
+   Enable/disable waveform tracing for all future signals declared in
+   all files.
+
+   With -file, enable/disable waveform tracing in the specified
+   filename (or wildcard with '\*' or '?'), and -line range of line
+   numbers (or all lines if omitted).
+
+   For tracing_off with -file, instances below any module in the
+   files/ranges specified will also not be traced.  To overcome this
+   feature, use tracing_on on the upper module declaration and on any
+   cells, or use the -scope flavor of the command.
+
+   With -scope enable/disable waveform tracing for the specified scope (or
+   wildcard with '\*' or '?'), and optional --levels number of levels
+   below.  These controls only take place after other file/line/module
+   based controls have indicated the signal should be traced.
+
+   With -levels (used with -scope), the number of levels below that
+   scope which the rule is to match, where 0 means all levels below, 1
+   the exact level as the provided scope, and 2 meaning an additional
+   level of children below the provided scope, etc.
@@ -67,7 +67,7 @@ which have low coverage are written to the output directory.

 Specifies if the coverage point does not include the count number of
 coverage hits, then the coverage point will be considered above the
-threashold, and the coverage report will put a "%" to indicate the coverage
+threshold, and the coverage report will put a "%" to indicate the coverage
 is not sufficient.  Defaults to 10.

 .. option:: --help
@@ -13,7 +13,7 @@ For an overview of use of verilator_gantt, see :ref:`Profiling`.
 Gantt Chart VCD
 ---------------

-Verilated_gnatt creates a value change dump (VCD) format dump file which
+Verilated_gantt creates a value change dump (VCD) format dump file which
 may be viewed in a waveform viewer (e.g. C<GTKWave>):

 .. figure:: figures/fig_gantt_min.png
@@ -72,7 +72,7 @@ verilator_gantt Arguments

 .. option:: <filename>

-The filename to read data from, defaults to "profile_threads.dat".
+The filename to read data from, defaults to "profile_exec.dat".

 .. option:: --help

@@ -185,7 +185,7 @@ or "`ifdef`"'s may break other tools.
 .. option:: /*verilator&32;no_clocker*/

   Specifies that the signal is used as clock or not. This information is
-   used by Verilator to mark the signal and any derrived signals as
+   used by Verilator to mark the signal and any derived signals as
   clocker.  See :vlopt:`--clk`.

   Same as :option:`clocker` and :option:`no_clocker` in configuration
@@ -217,7 +217,7 @@ or "`ifdef`"'s may break other tools.
   :option:`public_flat` signals.

   To force a marked signal from C++, set the corresponding `__VforceVal`
-   variable to the desired value, and the `__VforceEn` signal to the bitmask
+   variable to the desired value, and the `__VforceEn` signal to the bit-mask
   indicating which bits of the signal to force. To force all bits of the
   target signal, set `__VforceEn` to all ones. To release the signal (or part
   thereof), set appropriate bits of the `__VforceEn` signal to zero.
@@ -445,7 +445,7 @@ or "`ifdef`"'s may break other tools.
 .. option:: /*verilator&32;sc_bv*/

   Used after a port declaration.  It sets the port to be of
-   :code:`sc_bv<{width}>` type, instead of bool, vluint32_t or vluint64_t.
+   :code:`sc_bv<{width}>` type, instead of bool, uint32_t or uint64_t.
   This may be useful if the port width is parameterized and the
   instantiating C++ code wants to always have a sc_bv so it can accept any
   width.  In general you should avoid using this attribute when not
@@ -37,15 +37,15 @@ Does Verilator run under Windows?

 Yes, ideally run Ubuntu under Windows Subsystem for Linux (WSL2).
 Alternatively use Cygwin, though this tends to be slower and is not
-regurally tested.  Verilated output also compiles under Microsoft Visual
-C++, but this is also not regurally tested.
+regularly tested.  Verilated output also compiles under Microsoft Visual
+C++, but this is also not regularly tested.


 Can you provide binaries?
 """""""""""""""""""""""""

 You can install Verilator via the system package manager (apt, yum, etc.)
-on many Linux distributions, including Debian, Ubuntu, SuSE, RedHat, and
+on many Linux distributions, including Debian, Ubuntu, SuSE, Red Hat, and
 others.  These packages are provided by the Linux distributions and
 generally will lag the version of the mainline Verilator repository.  If no
 binary package is available for your distribution, how about you set one
@@ -72,23 +72,38 @@ a good thing for getting working silicon.
 Will Verilator output remain under my own license/copyright?
 """"""""""""""""""""""""""""""""""""""""""""""""""""""""""""

-Yes, it's just like using GCC on your programs; this is why Verilator uses
-the "GNU **Lesser** Public License Version 3" instead of the more typical
-"GNU Public License".  See the licenses for details, but in brief, if you
-change Verilator itself or the header files Verilator includes, you must
-make the source code available under the GNU Lesser Public License.
-However, Verilator output (the Verilated code) only "include"s the licensed
-files, and so you are **not** required to open-source release any output
-from Verilator.
+Your SystemVerilog, VPI/DPI, or main() C++ code remains under your own license.
+
+It's just like how using GCC on your programs does not change the copyright
+of your program; this is why Verilator uses the "GNU **Lesser** Public
+License Version 3" instead of the more typical "GNU Public License".  See
+the licenses for details.
+
+Some examples:
+
+* Any SystemVerilog or other input fed into Verilator remain your own.
+
+* Any of your VPI/DPI C++ routines that Verilator calls remain your own.
+
+* Any of your main() C++ code that calls into Verilator remain your own.
+
+* If you change Verilator itself, for example changing or adding a file
+  under the src/ directory in the repository, you must make the source code
+  available under the GNU Lesser Public License.
+
+* If you change a header Verilator provides, for example under include/ in
+  the repository, you must make the source code available under the GNU
+  Lesser Public License.

 You also have the option of using the Perl Artistic License, which again
-does not require you to release your Verilog or generated code, and also
-allows you to modify Verilator for internal use without distributing the
-modified version.  But please contribute back to the community!
+does not require you to release your Verilog, C++, or generated code. This
+license also allows you to modify Verilator for internal use without
+distributing the modified version.  But please contribute back to the
+community!

-One limit is that you cannot under either license release a closed-source
-Verilog simulation product incorporating Verilator. That is you can have a
-commercial product, but must make the source code available.
+Under both license you can offer a commercial product that is based on
+Verilator either directly or embedded within.  However under both licenses,
+any changes you make to Verilator for such a product must be open sourced.

 As is standard with Open Source, contributions back to Verilator will be
 placed under the Verilator copyright and LGPL/Artistic license.  Small test
@@ -134,7 +149,8 @@ B. Or, for finer-grained control, or C++ files with multiple Verilated
          ...
          Verilated::traceEverOn(true);
          VerilatedVcdC* tfp = new VerilatedVcdC;
-          topp->trace(tfp, 99);  // Trace 99 levels of hierarchy
+          topp->trace(tfp, 99);  // Trace 99 levels of hierarchy (or see below)
+          // tfp->dumpvars(1, "t");  // trace 1 level under "t"
          tfp->open("obj_dir/t_trace_ena_cc/simx.vcd");
          ...
          while (contextp->time() < sim_time && !contextp->gotFinish()) {
@@ -353,8 +369,8 @@ also use the "import DPI" SystemVerilog feature to call C code (see the
 chapter above).  There is also limited VPI access to public signals.

 If you want something more complex, since Verilator emits standard C++
-code, you can simply write your own C++ routines that can access and modify
-signal values without needing any PLI interface code, and call it with
+code, you can write your own C++ routines that can access and modify signal
+values without needing any PLI interface code, and call it with
 $c("{any_c++_statement}").

 See the :ref:`Connecting` section.
@@ -444,7 +460,7 @@ the signal, as you would any other member variable.
 Signals are the smallest of 8-bit unsigned chars (equivalent to uint8_t),
 16-bit unsigned shorts (uint16_t), 32-bit unsigned longs (uint32_t), or
 64-bit unsigned long longs (uint64_t) that fits the width of the signal.
-Generally, you can use just uint32_t's for 1 to 32 bits, or vluint64_t for
+Generally, you can use just uint32_t's for 1 to 32 bits, or uint64_t for
 1 to 64 bits, and the compiler will properly up-convert smaller entities.
 Note even signed ports are declared as unsigned; you must sign extend
 yourself to the appropriate signal width.
@@ -481,7 +497,7 @@ by your code or you'll get strange results.
 Should a module be in Verilog or SystemC?
 """""""""""""""""""""""""""""""""""""""""

-Sometimes there is a block that just interconnects instances, and have a
+Sometimes there is a block that only interconnects instances, and have a
 choice as to if you write it in Verilog or SystemC.  Everything else being
 equal, best performance is when Verilator sees all of the design.  So, look
 at the hierarchy of your design, labeling instances as to if they are
@@ -50,7 +50,7 @@ For --cc/--sc, it creates:
     - Make include file with class names (from --make gmake)
   * - *{prefix}*\ _hier.mk
     - Make file for hierarchy blocks (from --make gmake)
-   * - *{prefix|*\ _hierMkArgs.f
+   * - *{prefix}*\ _hierMkArgs.f
     - Arguments for hierarchical Verilation (from --make gmake)
   * - *{prefix}*\ _hierCMakeArgs.f
     - Arguments for hierarchical Verilation (from --make cmake)
@@ -62,13 +62,17 @@ For --cc/--sc, it creates:
     - Top level (SystemVerilog $root) internal header file
   * - *{prefix}*\ ___024root.cpp
     - Top level (SystemVerilog $root) internal C++ file
-   * - *{prefix}*___024root*{__n}*\ .cpp
-     - Additional top level internal C++ files (from --output-split)
+   * - *{prefix}*\ ___024root\ *{__n}*\ .cpp
+     - Additional top level internal C++ files
+   * - *{prefix}*\ ___024root\ *{__DepSet_hash__n}*\ .cpp
+     - Additional top level internal C++ files (hashed to reduce build times)
   * - *{prefix}*\ ___024root__Slow\ *{__n}*\ .cpp
     - Infrequent cold routines
-   * - *{prefix}*\ ___024root__Trace{__n}*\ .cpp
+   * - *{prefix}*\ ___024root\ *{__DepSet_hash__n}*\ .cpp
+     - Infrequent cold routines (hashed to reduce build times)
+   * - *{prefix}*\ ___024root__Trace\ *{__n}*\ .cpp
     - Wave file generation code (from --trace)
-   * - *{prefix}*\ ___024root__Trace__Slow{__n}*\ .cpp
+   * - *{prefix}*\ ___024root__Trace__Slow\ *{__n}*\ .cpp
     - Wave file generation code (from --trace)
   * - *{prefix}*\ __Dpi.h
     - DPI import and export declarations (from --dpi)
@@ -87,7 +91,9 @@ For --cc/--sc, it creates:
   * - *{prefix}{each_verilog_module}*\ .cpp
     - Lower level internal C++ files
   * - *{prefix}{each_verilog_module}{__n}*\ .cpp
-     - Additional lower C++ files (from --output-split)
+     - Additional lower C++ files
+   * - *{prefix}{each_verilog_module}{__DepSet_hash__n}*\ .cpp
+     - Additional lower C++ files (hased to reduce build times)

 For --hierarchy mode, it creates:

@@ -120,7 +126,7 @@ In certain debug and other modes, it also creates:
     - Debugging graph files (from --debug)
   * - *{prefix}{misc}*\ .tree
     - Debugging files (from --debug)
-   * - {mod_prefix}_{each_verilog_module}*{__n}*\ .vpp
+   * - {mod_prefix}_{each_verilog_base_filename}*\ .vpp
     - Pre-processed verilog (from --debug)

 After running Make, the C++ compiler may produce the following:
@@ -155,13 +161,13 @@ The Verilated executable may produce the following:
   * - gmon.out
     - GCC/clang code profiler output, often fed into :command:`verilator_profcfunc`
   * - profile.vlt
-     - -profile data file for :ref:`Thread PGO`
-   * - profile_threads.dat
-     - -profile-threads data file for :command:`verilator_gnatt`
+     - --prof-pgo data file for :ref:`Thread PGO`
+   * - profile_exec.dat
+     - --prof-exec data file for :command:`verilator_gantt`

 Verilator_gantt may produce the following:

 .. list-table::

-   * - profile_threads.vcd
+   * - profile_exec.vcd
     - Gantt report waveform output
@@ -77,7 +77,7 @@ OS Requirements
 ---------------

 Verilator is developed and has primary testing on Ubuntu, with additional
-testing on FreeBSD and Apple OS-X. Versions have also built on Redhat
+testing on FreeBSD and Apple OS-X. Versions have also built on Red Hat
 Linux, and other flavors of GNU/Linux-ish platforms. Verilator also works
 on Windows Subsystem for Linux (WSL2), Windows under Cygwin, and Windows
 under MinGW (gcc -mno-cygwin). Verilated output (not Verilator itself)
@@ -87,7 +87,7 @@ compiles under all the options above, plus using MSVC++.
 Install Prerequisites
 ---------------------

-To build or run Verilator you need these standard packages:
+To build or run Verilator, you need these standard packages:

 ::

@@ -98,13 +98,20 @@ To build or run Verilator you need these standard packages:
   sudo apt-get install libfl-dev  # Ubuntu only (ignore if gives error)
   sudo apt-get install zlibc zlib1g zlib1g-dev  # Ubuntu only (ignore if gives error)

-To build or run the following are optional but should be installed for good
-performance:
+To build or run Verilator, the following are optional but should be installed
+for good performance:

 ::

   sudo apt-get install ccache  # If present at build, needed for run
-   sudo apt-get install libgoogle-perftools-dev numactl perl-doc
+   sudo apt-get install libgoogle-perftools-dev numactl
+
+The following is optional but is recommended for nicely rendered command line
+help when running Verilator:
+
+::
+
+   sudo apt-get install perl-doc

 To build Verilator you will need to install these packages; these do not
 need to be present to run Verilator:
@@ -117,8 +124,9 @@ Those developing Verilator itself may also want these (see internals.rst):

 ::

-   sudo apt-get install gdb graphviz cmake clang clang-format-11 gprof lcov
-   sudo pip3 install sphinx sphinx_rtd_theme breathe
+   sudo apt-get install gdb graphviz cmake clang clang-format-14 gprof lcov
+   sudo apt-get install yapf3
+   sudo pip3 install sphinx sphinx_rtd_theme sphinxcontrib-spelling breathe
   cpan install Pod::Perldoc
   cpan install Parallel::Forker

@@ -92,7 +92,7 @@ appropriate code to detect failing cases at simulation runtime and print an

 Verilator likewise also asserts any "unique" or "priority" SystemVerilog
 keywords on case statement, as well as "unique" on if statements.  However,
-"priority if" is currently simply ignored.
+"priority if" is currently ignored.


 .. _Language Limitations:
@@ -136,7 +136,7 @@ ___05F (5F is the hex code of an underscore.)
 Bind
 ----

-sVerilator only supports bind to a target module name, not to an
+Verilator only supports bind to a target module name, not to an
 instance path.


@@ -174,9 +174,9 @@ Structures and Unions
 ---------------------

 Presently Verilator only supports packed structs and packed unions.  Rand
-and randc tags on members are simply ignored.  All structures and unions
-are represented as a single vector, which means that generating one member
-of a structure from blocking, and another from non-blocking assignments is
+and randc tags on members are ignored.  All structures and unions are
+represented as a single vector, which means that generating one member of a
+structure from blocking, and another from non-blocking assignments is
 unsupported.


@@ -340,17 +340,17 @@ Force statement
 ---------------

 Verilator supports the procedural `force` (and corresponding `release`)
-statement. The behaviour of the `force` statement however does not entirely
+statement. The behavior of the `force` statement however does not entirely
 comply with the IEEE 1800 SystemVerilog standard. According to the standard,
 when a procedural statement of the form `force a = b;` is executed, the
-simulation should behave as if from that point onwards, a continuous
+simulation should behave as if from that point forwards, a continuous
 assignment `assign a = b;` have been added to override the drivers of `a`.
 More specifically: the value of `a` should be updated, whenever the value of
 `b` changes, all the way until a `release a;` statement is executed.
 Verilator instead evaluates the current value of `b` at the time the `force`
 statement is executed, and forces `a` to that value, without updating it
 until a new `force` or `release` statement is encountered that applies to
-`a`. This non-standard behaviour is nevertheless consistent with some other
+`a`. This non-standard behavior is nevertheless consistent with some other
 simulators.


@@ -489,7 +489,7 @@ $test$plusargs, $value$plusargs

  .. code-block:: C++

-        Verilated::commandArgs(argc, argv);
+        {VerilatedContext*} ->commandArgs(argc, argv);

  to register the command line before calling $test$plusargs or
  $value$plusargs.
@@ -7,9 +7,9 @@
 Simulating (Verilated-Model Runtime)
 ************************************

-This section describes items related to simulating, that using a Verilated
-model's executable.  For the runtime arguments to a simulated model, see
-:ref:`Simulation Runtime Arguments`.
+This section describes items related to simulating, that is, the use of a
+Verilated model's executable.  For the runtime arguments to a simulated
+model, see :ref:`Simulation Runtime Arguments`.


 .. _Benchmarking & Optimization:
@@ -279,26 +279,25 @@ To use profiling:
   is being spent.


-.. _Thread Profiling:
+.. _Execution Profiling:

-Thread Profiling
-================
+Execution Profiling
+===================

-When using multithreaded mode (:vlopt:`--threads`), it is useful to see
-statistics and visualize how well the multiple CPUs are being utilized.
+For performance optimization, it is useful to see statistics and visualize how
+execution time is distributed in a verilated model.

-With the :vlopt:`--prof-threads` option, Verilator will:
+With the :vlopt:`--prof-exec` option, Verilator will:

-* Add code to the Verilated model to record the start and end time of each
-  macro-task across a number of calls to eval. (What is a macro-task?  See
-  the Verilator internals document (:file:`docs/internals.rst` in the
-  distribution.)
+* Add code to the Verilated model to record execution flow.

 * Add code to save profiling data in non-human-friendly form to the file
-  specified with :vlopt:`+verilator+prof+threads+file+\<filename\>`.
+  specified with :vlopt:`+verilator+prof+exec+file+\<filename\>`.

-* Add code to save profiling data for thread profile-guided
-  optimization. See :ref:`Thread PGO`.
+* In multi-threaded models, add code to record the start and end time of each
+  macro-task across a number of calls to eval. (What is a macro-task?  See the
+  Verilator internals document (:file:`docs/internals.rst` in the
+  distribution.)

 The :command:`verilator_gantt` program may then be run to transform the
 saved profiling file into a nicer visual format and produce some related
@@ -406,8 +405,8 @@ others as they prove beneficial.
 Thread Profile-Guided Optimization
 ----------------------------------

-Verilator supports thread profile-guided optimization (Thread PGO) to
-improve multithreaded performance.
+Verilator supports profile-guided optimization (Verilation) of multi-threaded
+models (Thread PGO) to improve performance.

 When using multithreading, Verilator computes how long macro tasks take and
 tries to balance those across threads.  (What is a macro-task?  See the
@@ -417,13 +416,14 @@ balanced, leading to decreased performance.  Thread PGO allows collecting
 profiling data to replace the estimates and better optimize these
 decisions.

-To use Thread PGO, Verilate the model with the :vlopt:`--prof-threads`
-option.
+To use Thread PGO, Verilate the model with the :vlopt:`--prof-pgo` option. This
+will code to the verilated model to save profiling data for profile-guided
+optimization.

 Run the model executable. When the executable exits, it will create a
 profile.vlt file.

-Rerun Verilator, optionally omitting the :vlopt:`--prof-threads` option,
+Rerun Verilator, optionally omitting the :vlopt:`--prof-pgo` option,
 and adding the profile.vlt generated earlier to the command line.

 Note there is no Verilator equivalent to GCC's --fprofile-use. Verilator's
@@ -433,8 +433,8 @@ directly without any prefix.
 If results from multiple simulations are to be used in generating the
 optimization, multiple simulation's profile.vlt may be concatenated
 externally, or each of the files may be fed as separate command line
-options into Verilator.  Verilator will simply sum the profile results, so
-a longer running test will have proportionally more weight for optimization
+options into Verilator.  Verilator will sum the profile results, so a
+longer running test will have proportionally more weight for optimization
 than a shorter running test.

 If you provide any profile feedback data to Verilator, and it cannot use
@@ -68,7 +68,7 @@ multi-core SoC.

 Verilator is run in hierarchical mode on the whole SoC.  Verilator will
 make two models, one for the CPU hierarchy block, and one for the SoC.  The
-Verialted code for the SoC will automatically call the CPU Verilated model.
+Verilated code for the SoC will automatically call the CPU Verilated model.

 The current hierarchical Verilation is based on :vlopt:`--lib-create`. Each
 hierarchy block is Verilated into a library. User modules of the hierarchy
@@ -221,9 +221,13 @@ model, it may be beneficial to performance to adjust the
 influences the partitioning of the model by adjusting the assumed execution
 time of DPI imports.

-The :vlopt:`--trace-threads` options can be used to produce trace dumps
-using multiple threads. If :vlopt:`--trace-threads` is set without
-:vlopt:`--threads`, then :vlopt:`--trace-threads` will imply
+When using :vlopt:`--trace` to perform VCD tracing, the VCD trace
+construction is parallelized using the same number of threads as specified
+with :vlopt:`--threads`, and is executed on the same thread pool as the model.
+
+The :vlopt:`--trace-threads` options can be used with :vlopt:`--trace-fst`
+to offload FST tracing using multiple threads. If :vlopt:`--trace-threads` is
+given without :vlopt:`--threads`, then :vlopt:`--trace-threads` will imply
 :vlopt:`--threads 1 <--threads>`, i.e.: the support libraries will be
 thread safe.

@@ -231,12 +235,12 @@ With :vlopt:`--trace-threads 0 <--trace-threads>`, trace dumps are produced
 on the main thread. This again gives the highest single thread performance.

 With :vlopt:`--trace-threads {N} <--trace-threads>`, where N is at least 1,
-N additional threads will be created and managed by the trace files (e.g.:
-VerilatedVcdC or VerilatedFstC), to generate the trace dump. The main
-thread will be released to proceed with execution as soon as possible,
-though some blocking of the main thread is still necessary while capturing
-the trace. Different trace formats can utilize a various number of
-threads. See the :vlopt:`--trace-threads` option.
+up to N additional threads will be created and managed by the trace files
+(e.g.: VerilatedFstC), to offload construction of the trace dump. The main
+thread will be released to proceed with execution as soon as possible, though
+some blocking of the main thread is still necessary while capturing the
+trace. FST tracing can utilize up to 2 offload threads, so there is no use
+of setting :vlopt:`--trace-threads` higher than 2 at the moment.

 When running a multithreaded model, the default Linux task scheduler often
 works against the model, by assuming threads are short lived, and thus
@@ -265,7 +269,7 @@ This will limit memory to socket 0, and threads to cores 0, 1, 2, 3,
 (presumably on socket 0) optimizing performance.  Of course this must be
 adjusted if you want another simulator using e.g. socket 1, or if you
 Verilated with a different number of threads.  To see what CPUs are
-actually used, use :vlopt:`--prof-threads`.
+actually used, use :vlopt:`--prof-exec`.


 Multithreaded Verilog and Library Support
@@ -441,7 +445,7 @@ SystemC include directories and link to the SystemC libraries.

 .. describe:: TRACE_THREADS

-   Optional. Generated multi-threaded trace dumping, same as
+   Optional. Generated multi-threaded FST trace dumping, same as
   "--trace-threads".

 .. describe:: TOP_MODULE
@@ -12,7 +12,7 @@ Disabling Warnings
 Warnings may be disabled in multiple ways:

 #. Disable the warning in the source code.  When the warning is printed it
-   will include a warning code.  Simply surround the offending line with a
+   will include a warning code.  Surround the offending line with a
   :code:`/*verilator&32;lint_off*/` and :code:`/*verilator&32;lint_on*/`
   metacomment pair:

@@ -162,7 +162,7 @@ List Of Warnings
         always @(posedge clk)  foo[0] <= ...
         always_comb foo[1] = ...

-   Simply use a different register for the flop:
+   Instead use a different register for the flop:

   .. code-block:: sv

@@ -284,7 +284,7 @@ List Of Warnings

   .. TODO better example

-   Warns that it is simply better style to use casez, and "?" in place of
+   Warns that it is better style to use casez, and "?" in place of
   "x"'s.  See
   `http://www.sunburst-design.com/papers/CummingsSNUG1999Boston_FullParallelCase_rev1_1.pdf
   <http://www.sunburst-design.com/papers/CummingsSNUG1999Boston_FullParallelCase_rev1_1.pdf>`_
@@ -447,7 +447,7 @@ List Of Warnings
              p0();
         endmodule

-   Other tools with similar warnings: Veriable's forbid_defparam_rule.
+   Other tools with similar warnings: Verible's forbid_defparam_rule.


 .. option:: DEPRECATED
@@ -518,7 +518,7 @@ List Of Warnings
   Another way DIDNOTCONVERGE may occur is if # delays are used to generate
   clocks.  Verilator ignores the delays and gives an :option:`ASSIGNDLY`
   or :option:`STMTDLY` warning.  If these were suppressed, due to the
-   absense of the delay, the code may now oscillate.
+   absence of the delay, the code may now oscillate.

   Finally, rare, more difficult cases can be debugged like a C++ program;
   either enter :command:`gdb` and use its tracing facilities, or edit the
@@ -528,7 +528,7 @@ List Of Warnings
 .. option:: ENDCAPSULATED

   Warns that a class member is declared is local or protected, but is
-   being accessed from outside that class (if local) or a derrived class
+   being accessed from outside that class (if local) or a derived class
   (if protected).

   Ignoring this warning will only suppress the lint check, it will
@@ -924,7 +924,7 @@ List Of Warnings
   simulate correctly.

   Other tools with similar warnings: Icarus Verilog's portbind, "warning:
-   Instantiating module ... with dangling impot port (...)". Slang's
+   Instantiating module ... with dangling input port (...)". Slang's
   unconnected-port, "port '...' has no connection".


@@ -1212,12 +1212,12 @@ List Of Warnings
   .. include:: ../../docs/gen/ex_STMTDLY_msg.rst

   This is a warning because Verilator does not support delayed statements.
-   It will simply ignore all such delays.  In many cases ignoring a delay
-   might be harmless, but if the delayed statement is, as in this example,
-   used to cause some important action at a later time, it might be an
-   important difference.
+   It will ignore all such delays.  In many cases ignoring a delay might be
+   harmless, but if the delayed statement is, as in this example, used to
+   cause some important action at a later time, it might be an important
+   difference.

-   Some possible work arounds:
+   Some possible workarounds:

   * Move the delayed statement into the C++ wrapper file, where the
     stimulus and clock generation can be done in C++.
@@ -1506,7 +1506,7 @@ List Of Warnings
   Error that a construct might be legal according to IEEE but is not
   currently supported by Verilator.

-   A typical workaround is to recode the construct into a simpler and more
+   A typical workaround is to rewrite the construct into a simpler and more
   common alternative language construct.

   Alternatively, check if the construct is supported by other tools, and
@@ -96,10 +96,11 @@ this.
 Each ``AstNode`` has pointers to up to four children, accessed by the
 ``op1p`` through ``op4p`` methods. These methods are then abstracted in a
 specific Ast\* node class to a more specific name. For example with the
-``AstIf`` node (for ``if`` statements), ``ifsp`` calls ``op2p`` to give the
+``AstIf`` node (for ``if`` statements), ``thensp`` calls ``op2p`` to give the
 pointer to the AST for the "then" block, while ``elsesp`` calls ``op3p`` to
 give the pointer to the AST for the "else" block, or NULL if there is not
-one.
+one. These accessors are automatically generated by ``astgen`` after
+parsing the ``@astgen`` directives in the specific ``AstNode`` subclasses.

 ``AstNode`` has the concept of a next and previous AST - for example the
 next and previous statements in a block. Pointers to the AST for these
@@ -268,13 +269,13 @@ Estimating Logic Costs

 To compute the cost of any given path through the graph, Verilator
 estimates an execution cost for each task. Each macro-task has an execution
-cost which is simply the sum of its tasks' costs. We assume that
-communication overhead and synchronization overhead are zero, so the cost
-of any given path through the graph is simply the sum of macro-task
-execution costs. Sarkar does almost the same thing, except that he has
-nonzero estimates for synchronization costs.
+cost which is the sum of its tasks' costs. We assume that communication
+overhead and synchronization overhead are zero, so the cost of any given
+path through the graph is the sum of macro-task execution costs. Sarkar
+does almost the same thing, except that he has nonzero estimates for
+synchronization costs.

-Verilator's cost estimates are assigned by ``InstrCountCostVisitor``.  This
+Verilator's cost estimates are assigned by ``InstrCountVisitor``.  This
 class is perhaps the most fragile piece of the multithread
 implementation. It's easy to have a bug where you count something cheap
 (eg. accessing one element of a huge array) as if it were expensive (eg.
@@ -301,7 +302,7 @@ prerequisites on other threads have finished.

 The synchronization cost is cheap if the prereqs are done. If they're not,
 fragmentation (idle CPU cores waiting) is possible. This is the major
-source of overhead in this approach. The ``--prof-threads`` switch and the
+source of overhead in this approach. The ``--prof-exec`` switch and the
 ``verilator_gantt`` script can visualize the time lost to such
 fragmentation.

@@ -501,22 +502,99 @@ code:
 The ``astgen`` Script
 ---------------------

-Some of the code implementing passes is extremely repetitive, and must be
-implemented for each sub-class of ``AstNode``. However, while repetitive,
-there is more variability than can be handled in C++ macros.
+The ``astgen`` script is used to generate some of the repetitive C++ code
+related to the ``AstNode`` type hierarchy. An example is the abstract ``visit``
+methods in ``VNVisitor``. There are other uses, please see the ``*__gen*``
+files in the bulid directories and the ``astgen`` script itself for details.  A
+description of the more advanced features of ``astgen`` are provided here.

-In Verilator this is implemented by using a script, ``astgen`` to
-pre-process the C++ code. For example in ``V3Const.cpp`` this is used to
-implement the ``visit()`` functions for each binary operation using the
-``TREEOP`` macro.

-The original C source code is transformed into C code in the ``obj_opt``
+Generating ``AstNode`` members
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Some of the member s of ``AstNode`` sub-classes are generated by ``astgen``.
+These are emitted as pre-processor macro definitions, which then need to be
+added to the ``AstNode`` sub-classes they correspond to. Specifically ``class
+AstFoo`` should contain an instance of ``ASTGEN_MEMBERS_Foo;`` at class scope.
+The ``astgen`` script checks and errors if this is not present. The method
+generated depends on whether the class is a concrete final class, or an
+abstract ``AstNode*`` base-class, and on ``@astgen`` directives present in
+comment sections in the body of the ``AstNode`` sub-class definitions.
+
+
+List of ``@astgen`` directives
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+``@astgen`` directives in comments contained in the body of ``AstNode``
+sub-class definitions are parsed and contribute to the code generated by
+``astgen``. The general syntax is ``@astgen <keywords> := <description>``,
+where ``<keywords>`` determines what is being defined, and ``<description>`` is
+a ``<keywords>`` dependent description of the definition. The list of
+``@astgen`` directives is as follows:
+
+
+``op<N>`` operand  directives
+"""""""""""""""""""""""""""""
+
+The ``op1``, ``op2``, ``op3`` and ``op4`` directives are used to describe the
+name and type of the up to 4 child operands of a node. The syntax of the
+``<description>`` field is ``<identifier> : <type>``, where ``<identifier>``
+will be used as the base name of the generated operand accessors, and
+``<type>`` is one of:
+
+1. An ``AstNode`` sub-class, defining the operand to be of that type, always
+   no-null, and with an always null ``nextp()``. That is, the child node is
+   always present, and is a single ``AstNode`` (as opposed to a list).
+
+2. ``Optional[<AstNode sub-class>]``. This is just like in point 1 above, but
+   defines the child node to be optional, meaning it may be null.
+
+3. ``List[AstNode sub-class]`` describes a list operand, which means the child
+   node may have a non-null ``nextp()`` and in addition the child itself may be
+   null, representing an empty list.
+
+
+An example of the full syntax of the directive is
+``@astgen op1 := lhsp : AstNodeMath``.
+
+``astnode`` generates accessors for the child nodes based on these directives.
+For non-list children, the names of the getter and setter both are that of the
+given ``<identifier>``. For list type children, the getter is ``<identifier>``,
+and instead of the setter, there an ``add<Identifier>`` method is generated
+that appends new nodes (or lists of nodes) to the child list.
+
+``alias op<N>`` operand alias directives
+""""""""""""""""""""""""""""""""""""""""
+
+If a super-class already defined a name and type for a child node using the
+``op<N>`` directive, but a more appropriate name exists in the context of a
+sub-class, then the alias directive can be used to introduce an additional name
+for the child node. The is ``alias op<N> := <identifier>`` where
+``<identifier>`` is the new name. ``op<N>`` must have been defined in some
+super-class of the current node.
+
+Example: ``@astgen alias op1 := condp``
+
+
+Additional features of ``astgen``
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+In addition to generating ``AstNode`` members as described above,
+``astgen`` is also use to handle some of the repetitive implementation code
+that is still variable enough not to be handled in C++ macros.
+
+In particular, ``astgen`` is used to pre-process some of the C++ source
+files. For example in ``V3Const.cpp``, it is used to implement the
+``visit()`` functions for each binary operation using the ``TREEOP`` macro.
+
+The original C++ source code is transformed into C++ code in the ``obj_opt``
 and ``obj_dbg`` sub-directories (the former for the optimized version of
 Verilator, the latter for the debug version). So for example
 ``V3Const.cpp`` into ``V3Const__gen.cpp``.


-Visitor Functions -----------------
+Visitor Functions
+-----------------

 Verilator uses the "Visitor" design pattern to implement its refinement and
 optimization passes. This allows separation of the pass algorithm from the
@@ -817,7 +895,7 @@ which you can install using cpan.

 There are some traps to avoid when running regression tests

- When checking the MANIFEST, the test will barf on unexpected code in the
+- When checking the MANIFEST, the test will fail on unexpected code in the
  Verilator tree. So make sure to keep any such code outside the tree.

 - Not all Linux systems install Perldoc by default. This is needed for the
@@ -1153,8 +1231,9 @@ Generally what would you do to add a new feature?
   language and has a lot of back-and-forth with Verilator's grammar. Copy
   the appropriate rules to src/verilog.y and modify the productions.

-4. If a new Ast type is needed, add it to V3AstNodes.h. Follow the
-   convention described above about the AstNode type hierarchy.
+4. If a new Ast type is needed, add it to the appropriate V3AstNode*.h.
+   Follow the convention described above about the AstNode type hierarchy.
+   Ordering of definitions is enforced by ``astgen``.

 5. Now you can run "test_regress/t/t_<newtestcase>.pl --debug" and it'll
   probably fail but you'll see a
@@ -1183,10 +1262,10 @@ Verilator ideally would support all of IEEE, and has the goal to get close
 to full support. However the following IEEE sections and features are not
 anticipated to be ever implemented for the reasons indicated.

-IEEE 1800-2017 3.3 recursive modules
+IEEE 1800-2017 3.3 modules within modules
    Little/no tool support, and arguably not a good practice.
 IEEE 1800-2017 6.12 "shortreal"
-    Little/no tool support, and easily simply promoted to real.
+    Little/no tool support, and easily promoted to real.
 IEEE 1800-2017 11.11 Min, typ, max
    No SDF support so will always use typical.
 IEEE 1800-2017 11.12 "let"
@@ -2,9 +2,11 @@ ABCp
 Accellera
 Affe
 Aleksander
+Alexandre
 Ami
 Amir
 Anastasiadis
+Anikin
 Antonin
 Antwerpen
 Arasanipalai
@@ -70,6 +72,7 @@ Eda
 Eddleston
 Egbert
 Egil
+Ehab
 Eiler
 Eivind
 El
@@ -82,6 +85,7 @@ Fabrizio
 Fekete
 Ferrandi
 Flachs
+Flavien
 Foletto
 Forker
 Francillon
@@ -104,6 +108,7 @@ Goessling
 Gonnen
 Goorah
 Gossner
+Graybeal
 Grobman
 Gunter
 Guo
@@ -121,6 +126,7 @@ Hornung
 Hossell
 Hsu
 Hyperthreading
+Ibrahim
 Iles
 Inlines
 Inout
@@ -134,6 +140,7 @@ Jannis
 Jens
 Jeras
 Jiuyang
+Joannou
 Joly
 Jullien
 Junji
@@ -147,6 +154,7 @@ Kamendje
 Kandadi
 Kaplan
 Karge
+Karlsson
 Katz
 Katzman
 Keren
@@ -161,6 +169,7 @@ Kolecki
 Koonce
 Korteland
 Koszek
+Kouping
 Kravitz
 Krolnik
 Kruse
@@ -194,6 +203,7 @@ Mednick
 Michiels
 Microsystems
 Milanovic
+Millis
 MinW
 Mindspeed
 Miodrag
@@ -224,12 +234,14 @@ Petr
 Piechotka
 Piersall
 Plunkett
+Popolon
 Popov
 Prabhat
 Prabhu
 Prateek
 Pre
 Preprocess
+Pretet
 Priyadharshini
 Pullup
 Pulver
@@ -262,12 +274,15 @@ Shi
 Shinkarovsky
 Shirakawa
 Shuba
+Shunyao
 Slatter
 SoC
 Sobhan
 Sokorac
 Solaris
 Solomatnikov
+Solt
+Southwell
 Srini
 Stamness
 Stephane
@@ -286,6 +301,7 @@ SystemVerilog
 Takatsukasa
 Tambe
 Tariq
+Tejada
 Tengstrand
 Terpstra
 Thiede
@@ -293,8 +309,10 @@ Thierry
 Thyer
 Tichelaar
 Tomov
+Tood
 Topa
 Tota
+Trefor
 Tresidder
 Tri
 Tristate
@@ -304,11 +322,13 @@ Ubixum
 Uints
 Undefines
 Unsized
+Urbach
 Uselib
 Usha
 Usuario
 VERILATOR
 Vasu
+Vdeeptemp
 Vdly
 Vemumtab
 Vemuri
@@ -351,7 +371,9 @@ Zhang
 abirkmanis
 accessor
 accessors
+adrienlemasle
 agrobman
+ahouska
 al
 ala
 andit
@@ -372,8 +394,12 @@ backtrace
 backtraces
 basename
 bbox
+benchmarking
 biguint
 biops
+bitOpTree
+bitOpTree
+bitop
 bitstoreal
 blackbox
 bokke
@@ -389,6 +415,7 @@ casez
 casted
 cb
 ccache
+ccall
 cdc
 ceil
 celldefine
@@ -411,6 +438,8 @@ concat
 concats
 config
 const
+constexpr
+constpool
 coredump
 countbits
 countones
@@ -426,6 +455,7 @@ da
 dat
 datadir
 datafiles
+david
 ddd
 deassign
 debugi
@@ -434,6 +464,7 @@ defname
 defparam
 demangling
 der
+dereference
 desassign
 destructor
 detections
@@ -462,6 +493,7 @@ dumpvars
 dut
 dx
 elab
+elike
 elsif
 endcase
 endcelldefine
@@ -480,15 +512,18 @@ enums
 env
 envvar
 eof
+errae
 erroring
 et
 eval
+evals
 exe
 executables
 expr
 extern
 fanin
 fasttrace
+fauto
 fbranch
 fclose
 fdisplay
@@ -503,6 +538,7 @@ filt
 flto
 flushCall
 fopen
+forceable
 foreach
 fprintf
 fprofile
@@ -521,6 +557,7 @@ funcs
 fwrite
 gantt
 gcc
+gcda
 gdb
 genblk
 genvar
@@ -552,6 +589,7 @@ incdir
 includer
 inferfaces
 inhibitSim
+initarray
 initializer
 initializers
 inits
@@ -570,6 +608,7 @@ killua
 lang
 lcov
 ld
+leavinel
 len
 libext
 libgoogle
@@ -584,6 +623,7 @@ ln
 loc
 localparam
 localparams
+localtime
 logicals
 longint
 lsb
@@ -618,6 +658,7 @@ multithreaded
 multithreading
 mutexes
 mux
+myftptoyman
 mysignal
 namespace
 nand
@@ -642,15 +683,19 @@ onehot
 ooo
 oprofile
 oversubscription
+parallelized
 param
 parameterized
 params
 parens
+pawel
 pc
 pdf
 perf
 perftools
+pgo
 picoChip
+pinIndex
 pinout
 plusargs
 pmos
@@ -676,6 +721,7 @@ prev
 printf
 printtimescale
 profcfunc
+profiler
 prototyptes
 ps
 pthread
@@ -703,12 +749,14 @@ regs
 reloop
 resetall
 respecified
+rodata
 rr
 rst
 runtime
 runtimes
 rw
 sVerilator
+sawatzke
 sc
 scalared
 sccanf
@@ -724,6 +772,7 @@ specparam
 splitme
 spp
 sqrt
+src
 srcdir
 srcfile
 sscanf
@@ -743,6 +792,7 @@ subcells
 subexpressions
 submodule
 submodules
+substring
 sv
 svBitVal
 svBitVecVal
@@ -777,6 +827,7 @@ trunc
 txt
 typ
 typedef
+typedef'ed
 typedefed
 typedefs
 typename
@@ -790,6 +841,7 @@ uniquified
 unistd
 unlink
 unlinked
+unnamedblk
 unopt
 unoptflat
 unoptimizable
@@ -839,11 +891,14 @@ writeme
 writemem
 writememb
 writememh
+xiak
 xin
 xml
 xnor
 xout
 xuejiazidi
 yanx
+ypq
 yurivict
 zdave
+Øyvind
@@ -46,9 +46,6 @@ The XML document consists of 4 sections within the top level
   hierarchy. Each instance is represented with the ``<cell>`` element
   with the following attributes:

-   -  ``fl`` (deprecated): The file id and line number where the module
-      was instanced. Use ``loc`` instead.
-
   -  ``loc``: The file id, first line number, last line number, first
      column number and last column number of the identifier where the
      module was instanced, separated by commas.
@@ -33,5 +33,5 @@ add_executable(example ../make_tracing_c/sim_main.cpp)
 # Add the Verilated circuit to the target
 verilate(example COVERAGE TRACE
  INCLUDE_DIRS "../make_tracing_c"
-  VERILATOR_ARGS -f ../make_tracing_c/input.vc -Os -x-assign 0
+  VERILATOR_ARGS -f ../make_tracing_c/input.vc -x-assign fast
  SOURCES ../make_tracing_c/top.v)
@@ -45,7 +45,7 @@ set_property(
 # Add the Verilated circuit to the target
 verilate(example SYSTEMC COVERAGE TRACE
  INCLUDE_DIRS "../make_tracing_sc"
-  VERILATOR_ARGS -f ../make_tracing_sc/input.vc -Os -x-assign 0
+  VERILATOR_ARGS -f ../make_tracing_sc/input.vc -x-assign fast
  SOURCES ../make_tracing_sc/top.v)

 verilator_link_systemc(example)
@@ -21,11 +21,14 @@ int main(int argc, char** argv, char** env) {
    // Prevent unused variable warnings
    if (false && argc && argv && env) {}

+    // Construct a VerilatedContext to hold simulation time, etc.
+    VerilatedContext* contextp = new VerilatedContext;
+
    // Construct the Verilated model, from Vtop.h generated from Verilating "top.v"
-    Vtop* top = new Vtop;
+    Vtop* top = new Vtop{contextp};

    // Simulate until $finish
-    while (!Verilated::gotFinish()) {
+    while (!contextp->gotFinish()) {

        // Evaluate model
        top->eval();
@@ -33,7 +33,7 @@ VERILATOR_FLAGS =
 # Generate C++
 VERILATOR_FLAGS += -cc
 # Optimize
-VERILATOR_FLAGS += -Os -x-assign 0
+VERILATOR_FLAGS += -x-assign fast
 # Warn abount lint issues; may not want this on less solid designs
 VERILATOR_FLAGS += -Wall
 # This example does not use vl_time_stamp but rather
@@ -32,7 +32,7 @@ int main(int argc, char** argv, char** env) {
    // When tracing, the contents of the secret module will not be seen
    VerilatedVcdC* tfp = nullptr;
    const char* flag = contextp->commandArgsPlusMatch("trace");
-    if (flag && 0 == strcmp(flag, "+trace")) {
+    if (flag && 0 == std::strcmp(flag, "+trace")) {
        contextp->traceEverOn(true);
        VL_PRINTF("Enabling waves into logs/vlt_dump.vcd...\n");
        tfp = new VerilatedVcdC;
@@ -36,7 +36,7 @@ VERILATOR_FLAGS += -cc --exe
 # Generate makefile dependencies (not shown as complicates the Makefile)
 #VERILATOR_FLAGS += -MMD
 # Optimize
-VERILATOR_FLAGS += -Os -x-assign 0
+VERILATOR_FLAGS += -x-assign fast
 # Warn abount lint issues; may not want this on less solid designs
 VERILATOR_FLAGS += -Wall
 # Make waveforms
@@ -34,6 +34,8 @@ int main(int argc, char** argv, char** env) {
    // Using unique_ptr is similar to
    // "VerilatedContext* contextp = new VerilatedContext" then deleting at end.
    const std::unique_ptr<VerilatedContext> contextp{new VerilatedContext};
+    // Do not instead make Vtop as a file-scope static variable, as the
+    // "C++ static initialization order fiasco" may cause a crash

    // Set debug level, 0 is off, 9 is highest presently used
    // May be overridden by commandArgs argument parsing
@@ -69,7 +71,7 @@ int main(int argc, char** argv, char** env) {
        // Historical note, before Verilator 4.200 Verilated::gotFinish()
        // was used above in place of contextp->gotFinish().
        // Most of the contextp-> calls can use Verilated:: calls instead;
-        // the Verilated:: versions simply assume there's a single context
+        // the Verilated:: versions just assume there's a single context
        // being used (per thread).  It's faster and clearer to use the
        // newer contextp-> versions.

@@ -37,7 +37,7 @@ VERILATOR_FLAGS += -sc --exe
 # Generate makefile dependencies (not shown as complicates the Makefile)
 #VERILATOR_FLAGS += -MMD
 # Optimize
-VERILATOR_FLAGS += -Os -x-assign 0
+VERILATOR_FLAGS += -x-assign fast
 # Warn abount lint issues; may not want this on less solid designs
 VERILATOR_FLAGS += -Wall
 # Make waveforms
@@ -58,11 +58,11 @@ int sc_main(int argc, char* argv[]) {

    // Define interconnect
    sc_signal<bool> reset_l;
-    sc_signal<vluint32_t> in_small;
-    sc_signal<vluint64_t> in_quad;
+    sc_signal<uint32_t> in_small;
+    sc_signal<uint64_t> in_quad;
    sc_signal<sc_bv<70>> in_wide;
-    sc_signal<vluint32_t> out_small;
-    sc_signal<vluint64_t> out_quad;
+    sc_signal<uint32_t> out_small;
+    sc_signal<uint64_t> out_quad;
    sc_signal<sc_bv<70>> out_wide;

    // Construct the Verilated model, from inside Vtop.h
@@ -82,14 +82,14 @@ int sc_main(int argc, char* argv[]) {

    // You must do one evaluation before enabling waves, in order to allow
    // SystemC to interconnect everything for testing.
-    sc_start(1, SC_NS);
+    sc_start(SC_ZERO_TIME);

 #if VM_TRACE
    // If verilator was invoked with --trace argument,
    // and if at run time passed the +trace argument, turn on tracing
    VerilatedVcdSc* tfp = nullptr;
    const char* flag = Verilated::commandArgsPlusMatch("trace");
-    if (flag && 0 == strcmp(flag, "+trace")) {
+    if (flag && 0 == std::strcmp(flag, "+trace")) {
        cout << "Enabling waves into logs/vlt_dump.vcd...\n";
        tfp = new VerilatedVcdSc;
        top->trace(tfp, 99);  // Trace 99 levels of hierarchy
@@ -16,12 +16,13 @@ from shutil import copy2


 class VlFileCopy:
+
    def __init__(
-        self,
-        verilator_args,  # presently all verilator options are passed-thru
-        # ideally this script would check against options mentioned in help
+            self,
+            verilator_args,  # presently all verilator options are passed-thru
+            # ideally this script would check against options mentioned in help
        debug=0,
-        output_dir='copied'):  # directory name we output file uses
+            output_dir='copied'):  # directory name we output file uses

        self.debug = debug

@@ -14,12 +14,13 @@ import xml.etree.ElementTree as ET


 class VlHierGraph:
+
    def __init__(
-        self,
-        verilator_args,  # presently all verilator options are passed-thru
-        # ideally this script would check against options mentioned in help
+            self,
+            verilator_args,  # presently all verilator options are passed-thru
+            # ideally this script would check against options mentioned in help
        debug=0,
-        output_filename='graph.dot'):  # output filename
+            output_filename='graph.dot'):  # output filename
        self.debug = debug
        self.next_vertex_number = 0
        self.name_to_number = {}
@@ -140,6 +140,10 @@ void **JenkinsIns(void *base_i, const unsigned char *mem, uint32_t length, uint3
 #include <sys/sysctl.h>
 #endif

+#if defined(FST_MACOSX) || defined(__MINGW32__) || defined(__OpenBSD__) || defined(__FreeBSD__)
+#define FST_UNBUFFERED_IO
+#endif
+
 #ifdef __GNUC__
 /* Boolean expression more often true than false */
 #define FST_LIKELY(x) __builtin_expect(!!(x), 1)
@@ -4577,12 +4581,11 @@ if(sectype == FST_BL_ZWRAPPER)
                if(!fcomp) { tmpfile_close(&fcomp, &xc->f_nam); return(0); }
                }

-#if defined(FST_MACOSX)
+#if defined(FST_UNBUFFERED_IO)
        setvbuf(fcomp, (char *)NULL, _IONBF, 0);   /* keeps gzip from acting weird in tandem with fopen */
 #endif

 #ifdef __MINGW32__
-        setvbuf(fcomp, (char *)NULL, _IONBF, 0);   /* keeps gzip from acting weird in tandem with fopen */
        xc->filename_unpacked = hf;
 #else
        if(hf)
@@ -4880,7 +4883,7 @@ if((!nam)||(!(xc->f=fopen(nam, "rb"))))
        char *hf = (char *)calloc(1, flen + 6);
        int rc;

-#if defined(__MINGW32__) || defined(FST_MACOSX)
+#if defined(FST_UNBUFFERED_IO)
        setvbuf(xc->f, (char *)NULL, _IONBF, 0);   /* keeps gzip from acting weird in tandem with fopen */
 #endif

@@ -47,36 +47,44 @@

 #define VERILATOR_VERILATED_CPP_

-#include "verilatedos.h"
-#include "verilated_imp.h"
-
 #include "verilated_config.h"
+#include "verilatedos.h"
+
+#include "verilated_imp.h"

 #include <algorithm>
 #include <cctype>
 #include <cerrno>
-#include <sstream>
-#include <sys/stat.h>  // mkdir
-#include <list>
+#include <cstdlib>
 #include <limits>
+#include <list>
+#include <sstream>
 #include <utility>

+#include <sys/stat.h>  // mkdir
+
 // clang-format off
 #if defined(_WIN32) || defined(__MINGW32__)
 # include <direct.h>  // mkdir
 #endif
+
+#ifdef VL_THREADED
+# include "verilated_threads.h"
+#endif
 // clang-format on

+#include "verilated_trace.h"
+
 // Max characters in static char string for VL_VALUE_STRING
 constexpr unsigned VL_VALUE_STRING_MAX_WIDTH = 8192;

 //===========================================================================
 // Static sanity checks

-static_assert(sizeof(vluint8_t) == 1, "vluint8_t is missized");
-static_assert(sizeof(vluint16_t) == 2, "vluint8_t is missized");
-static_assert(sizeof(vluint32_t) == 4, "vluint8_t is missized");
-static_assert(sizeof(vluint64_t) == 8, "vluint8_t is missized");
+static_assert(sizeof(uint8_t) == 1, "uint8_t is missized");
+static_assert(sizeof(uint16_t) == 2, "uint8_t is missized");
+static_assert(sizeof(uint32_t) == 4, "uint8_t is missized");
+static_assert(sizeof(uint64_t) == 8, "uint8_t is missized");

 //===========================================================================
 // Global variables
@@ -243,21 +251,21 @@ std::string _vl_string_vprintf(const char* formatp, va_list ap) VL_MT_SAFE {
    return out;
 }

-vluint64_t _vl_dbg_sequence_number() VL_MT_SAFE {
+uint64_t _vl_dbg_sequence_number() VL_MT_SAFE {
 #ifdef VL_THREADED
-    static std::atomic<vluint64_t> sequence;
+    static std::atomic<uint64_t> sequence;
 #else
-    static vluint64_t sequence = 0;
+    static uint64_t sequence = 0;
 #endif
    return ++sequence;
 }

-vluint32_t VL_THREAD_ID() VL_MT_SAFE {
+uint32_t VL_THREAD_ID() VL_MT_SAFE {
 #ifdef VL_THREADED
    // Alternative is to use std::this_thread::get_id, but that returns a
    // hard-to-read number and is very slow
-    static std::atomic<vluint32_t> s_nextId(0);
-    static VL_THREAD_LOCAL vluint32_t t_myId = ++s_nextId;
+    static std::atomic<uint32_t> s_nextId(0);
+    static VL_THREAD_LOCAL uint32_t t_myId = ++s_nextId;
    return t_myId;
 #else
    return 0;
@@ -295,7 +303,7 @@ void VL_PRINTF_MT(const char* formatp, ...) VL_MT_SAFE {
 //===========================================================================
 // Random -- Mostly called at init time, so not inline.

-static vluint32_t vl_sys_rand32() VL_MT_UNSAFE {
+static uint32_t vl_sys_rand32() VL_MT_UNSAFE {
    // Return random 32-bits using system library.
    // Used only to construct seed for Verilator's PNRG.
    static VerilatedMutex s_mutex;
@@ -308,9 +316,9 @@ static vluint32_t vl_sys_rand32() VL_MT_UNSAFE {
 #endif
 }

-vluint64_t vl_rand64() VL_MT_SAFE {
-    static VL_THREAD_LOCAL vluint64_t t_state[2];
-    static VL_THREAD_LOCAL vluint32_t t_seedEpoch = 0;
+uint64_t vl_rand64() VL_MT_SAFE {
+    static VL_THREAD_LOCAL uint64_t t_state[2];
+    static VL_THREAD_LOCAL uint32_t t_seedEpoch = 0;
    // For speed, we use a thread-local epoch number to know when to reseed
    // A thread always belongs to a single context, so this works out ok
    if (VL_UNLIKELY(t_seedEpoch != VerilatedContextImp::randSeedEpoch())) {
@@ -324,7 +332,7 @@ vluint64_t vl_rand64() VL_MT_SAFE {
        if (VL_COUNTONES_I(t_state[1]) < 10) t_state[1] = ~t_state[1];
    }
    // Xoroshiro128+ algorithm
-    const vluint64_t result = t_state[0] + t_state[1];
+    const uint64_t result = t_state[0] + t_state[1];
    t_state[1] ^= t_state[0];
    t_state[0] = (((t_state[0] << 55) | (t_state[0] >> 9)) ^ t_state[1] ^ (t_state[1] << 14));
    t_state[1] = (t_state[1] << 36) | (t_state[1] >> 28);
@@ -409,11 +417,11 @@ WDataOutP _vl_moddiv_w(int lbits, WDataOutP owp, const WDataInP lwp, const WData
    const int vw = VL_WORDS_I(vmsbp1);  // aka "n" in the algorithm

    if (vw == 1) {  // Single divisor word breaks rest of algorithm
-        vluint64_t k = 0;
+        uint64_t k = 0;
        for (int j = uw - 1; j >= 0; --j) {
-            const vluint64_t unw64 = ((k << 32ULL) + static_cast<vluint64_t>(lwp[j]));
-            owp[j] = unw64 / static_cast<vluint64_t>(rwp[0]);
-            k = unw64 - static_cast<vluint64_t>(owp[j]) * static_cast<vluint64_t>(rwp[0]);
+            const uint64_t unw64 = ((k << 32ULL) + static_cast<uint64_t>(lwp[j]));
+            owp[j] = unw64 / static_cast<uint64_t>(rwp[0]);
+            k = unw64 - static_cast<uint64_t>(owp[j]) * static_cast<uint64_t>(rwp[0]);
        }
        if (is_modulus) {
            owp[0] = k;
@@ -423,8 +431,8 @@ WDataOutP _vl_moddiv_w(int lbits, WDataOutP owp, const WDataInP lwp, const WData
    }

    // +1 word as we may shift during normalization
-    vluint32_t un[VL_MULS_MAX_WORDS + 1];  // Fixed size, as MSVC++ doesn't allow [words] here
-    vluint32_t vn[VL_MULS_MAX_WORDS + 1];  // v normalized
+    uint32_t un[VL_MULS_MAX_WORDS + 1];  // Fixed size, as MSVC++ doesn't allow [words] here
+    uint32_t vn[VL_MULS_MAX_WORDS + 1];  // v normalized

    // Zero for ease of debugging and to save having to zero for shifts
    // Note +1 as loop will use extra word
@@ -433,7 +441,7 @@ WDataOutP _vl_moddiv_w(int lbits, WDataOutP owp, const WDataInP lwp, const WData
    // Algorithm requires divisor MSB to be set
    // Copy and shift to normalize divisor so MSB of vn[vw-1] is set
    const int s = 31 - VL_BITBIT_I(vmsbp1 - 1);  // shift amount (0...31)
-    const vluint32_t shift_mask = s ? 0xffffffff : 0;  // otherwise >> 32 won't mask the value
+    const uint32_t shift_mask = s ? 0xffffffff : 0;  // otherwise >> 32 won't mask the value
    for (int i = vw - 1; i > 0; --i) {
        vn[i] = (rwp[i] << s) | (shift_mask & (rwp[i - 1] >> (32 - s)));
    }
@@ -453,10 +461,10 @@ WDataOutP _vl_moddiv_w(int lbits, WDataOutP owp, const WDataInP lwp, const WData
    // Main loop
    for (int j = uw - vw; j >= 0; --j) {
        // Estimate
-        const vluint64_t unw64 = (static_cast<vluint64_t>(un[j + vw]) << 32ULL
-                                  | static_cast<vluint64_t>(un[j + vw - 1]));
-        vluint64_t qhat = unw64 / static_cast<vluint64_t>(vn[vw - 1]);
-        vluint64_t rhat = unw64 - qhat * static_cast<vluint64_t>(vn[vw - 1]);
+        const uint64_t unw64
+            = (static_cast<uint64_t>(un[j + vw]) << 32ULL | static_cast<uint64_t>(un[j + vw - 1]));
+        uint64_t qhat = unw64 / static_cast<uint64_t>(vn[vw - 1]);
+        uint64_t rhat = unw64 - qhat * static_cast<uint64_t>(vn[vw - 1]);

    again:
        if (qhat >= 0x100000000ULL || ((qhat * vn[vw - 2]) > ((rhat << 32ULL) + un[j + vw - 2]))) {
@@ -465,10 +473,10 @@ WDataOutP _vl_moddiv_w(int lbits, WDataOutP owp, const WDataInP lwp, const WData
            if (rhat < 0x100000000ULL) goto again;
        }

-        vlsint64_t t = 0;  // Must be signed
-        vluint64_t k = 0;
+        int64_t t = 0;  // Must be signed
+        uint64_t k = 0;
        for (int i = 0; i < vw; ++i) {
-            const vluint64_t p = qhat * vn[i];  // Multiply by estimate
+            const uint64_t p = qhat * vn[i];  // Multiply by estimate
            t = un[i + j] - k - (p & 0xFFFFFFFFULL);  // Subtract
            un[i + j] = t;
            k = (p >> 32ULL) - (t >> 32ULL);
@@ -482,7 +490,7 @@ WDataOutP _vl_moddiv_w(int lbits, WDataOutP owp, const WDataInP lwp, const WData
            owp[j]--;
            k = 0;
            for (int i = 0; i < vw; ++i) {
-                t = static_cast<vluint64_t>(un[i + j]) + static_cast<vluint64_t>(vn[i]) + k;
+                t = static_cast<uint64_t>(un[i + j]) + static_cast<uint64_t>(vn[i]) + k;
                un[i + j] = t;
                k = t >> 32ULL;
            }
@@ -613,7 +621,7 @@ double VL_ITOR_D_W(int lbits, const WDataInP lwp) VL_PURE {
 }
 double VL_ISTOR_D_W(int lbits, const WDataInP lwp) VL_PURE {
    if (!VL_SIGN_W(lbits, lwp)) return VL_ITOR_D_W(lbits, lwp);
-    vluint32_t pos[VL_MULS_MAX_WORDS + 1];  // Fixed size, as MSVC++ doesn't allow [words] here
+    uint32_t pos[VL_MULS_MAX_WORDS + 1];  // Fixed size, as MSVC++ doesn't allow [words] here
    VL_NEGATE_W(VL_WORDS_I(lbits), pos, lwp);
    _vl_clean_inplace_w(lbits, pos);
    return -VL_ITOR_D_W(lbits, pos);
@@ -672,7 +680,10 @@ std::string _vl_vsformat_time(char* tmp, T ld, int timeunit, bool left, size_t w
    if (std::numeric_limits<T>::is_integer) {
        constexpr int b = 128;
        constexpr int w = VL_WORDS_I(b);
-        VlWide<w> tmp0, tmp1, tmp2, tmp3;
+        VlWide<w> tmp0;
+        VlWide<w> tmp1;
+        VlWide<w> tmp2;
+        VlWide<w> tmp3;

        WDataInP shifted = VL_EXTEND_WQ(b, 0, tmp0, static_cast<QData>(ld));
        if (shift < 0) {
@@ -687,10 +698,11 @@ std::string _vl_vsformat_time(char* tmp, T ld, int timeunit, bool left, size_t w
        const WDataInP integer = VL_DIV_WWW(b, tmp0, shifted, fracDigitsPow10);
        const WDataInP frac = VL_MODDIV_WWW(b, tmp1, shifted, fracDigitsPow10);
        const WDataInP max64Bit
-            = VL_EXTEND_WQ(b, 0, tmp2, std::numeric_limits<vluint64_t>::max());  // breaks shifted
+            = VL_EXTEND_WQ(b, 0, tmp2, std::numeric_limits<uint64_t>::max());  // breaks shifted
        if (VL_GT_W(w, integer, max64Bit)) {
            WDataOutP v = VL_ASSIGN_W(b, tmp3, integer);  // breaks fracDigitsPow10
-            VlWide<w> zero, ten;
+            VlWide<w> zero;
+            VlWide<w> ten;
            VL_ZERO_W(b, zero);
            VL_EXTEND_WI(b, 0, ten, 10);
            char buf[128];  // 128B is obviously long enough to represent 128bit integer in decimal
@@ -711,7 +723,7 @@ std::string _vl_vsformat_time(char* tmp, T ld, int timeunit, bool left, size_t w
                                     fracDigits, VL_SET_QW(frac), suffix.c_str());
            }
        } else {
-            const vluint64_t integer64 = VL_SET_QW(integer);
+            const uint64_t integer64 = VL_SET_QW(integer);
            if (!fracDigits) {
                digits = VL_SNPRINTF(tmp, VL_VALUE_STRING_MAX_WIDTH, "%" PRIu64 "%s", integer64,
                                     suffix.c_str());
@@ -878,9 +890,9 @@ void _vl_vsformat(std::string& output, const char* formatp, va_list ap) VL_MT_SA
                    int digits = 0;
                    std::string append;
                    if (lbits <= VL_QUADSIZE) {
-                        digits = VL_SNPRINTF(
-                            t_tmp, VL_VALUE_STRING_MAX_WIDTH, "%" PRId64,
-                            static_cast<vlsint64_t>(VL_EXTENDS_QQ(lbits, lbits, ld)));
+                        digits
+                            = VL_SNPRINTF(t_tmp, VL_VALUE_STRING_MAX_WIDTH, "%" PRId64,
+                                          static_cast<int64_t>(VL_EXTENDS_QQ(lbits, lbits, ld)));
                        append = t_tmp;
                    } else {
                        if (VL_SIGN_E(lbits, lwp[VL_WORDS_I(lbits) - 1])) {
@@ -991,22 +1003,22 @@ void _vl_vsformat(std::string& output, const char* formatp, va_list ap) VL_MT_SA
    }
 }

-static inline bool _vl_vsss_eof(FILE* fp, int floc) VL_MT_SAFE {
+static bool _vl_vsss_eof(FILE* fp, int floc) VL_MT_SAFE {
    if (VL_LIKELY(fp)) {
        return std::feof(fp) ? true : false;  // true : false to prevent MSVC++ warning
    } else {
        return floc < 0;
    }
 }
-static inline void _vl_vsss_advance(FILE* fp, int& floc) VL_MT_SAFE {
+static void _vl_vsss_advance(FILE* fp, int& floc) VL_MT_SAFE {
    if (VL_LIKELY(fp)) {
        std::fgetc(fp);
    } else {
        floc -= 8;
    }
 }
-static inline int _vl_vsss_peek(FILE* fp, int& floc, const WDataInP fromp,
-                                const std::string& fstr) VL_MT_SAFE {
+static int _vl_vsss_peek(FILE* fp, int& floc, const WDataInP fromp,
+                         const std::string& fstr) VL_MT_SAFE {
    // Get a character without advancing
    if (VL_LIKELY(fp)) {
        const int data = std::fgetc(fp);
@@ -1023,17 +1035,16 @@ static inline int _vl_vsss_peek(FILE* fp, int& floc, const WDataInP fromp,
        }
    }
 }
-static inline void _vl_vsss_skipspace(FILE* fp, int& floc, const WDataInP fromp,
-                                      const std::string& fstr) VL_MT_SAFE {
+static void _vl_vsss_skipspace(FILE* fp, int& floc, const WDataInP fromp,
+                               const std::string& fstr) VL_MT_SAFE {
    while (true) {
        const int c = _vl_vsss_peek(fp, floc, fromp, fstr);
        if (c == EOF || !std::isspace(c)) return;
        _vl_vsss_advance(fp, floc);
    }
 }
-static inline void _vl_vsss_read_str(FILE* fp, int& floc, const WDataInP fromp,
-                                     const std::string& fstr, char* tmpp,
-                                     const char* acceptp) VL_MT_SAFE {
+static void _vl_vsss_read_str(FILE* fp, int& floc, const WDataInP fromp, const std::string& fstr,
+                              char* tmpp, const char* acceptp) VL_MT_SAFE {
    // Read into tmp, consisting of characters from acceptp list
    char* cp = tmpp;
    while (true) {
@@ -1047,9 +1058,8 @@ static inline void _vl_vsss_read_str(FILE* fp, int& floc, const WDataInP fromp,
    *cp++ = '\0';
    // VL_DBG_MSGF(" _read got='"<<tmpp<<"'\n");
 }
-static inline char* _vl_vsss_read_bin(FILE* fp, int& floc, const WDataInP fromp,
-                                      const std::string& fstr, char* beginp, std::size_t n,
-                                      const bool inhibit = false) {
+static char* _vl_vsss_read_bin(FILE* fp, int& floc, const WDataInP fromp, const std::string& fstr,
+                               char* beginp, std::size_t n, const bool inhibit = false) {
    // Variant of _vl_vsss_read_str using the same underlying I/O functions but optimized
    // specifically for block reads of N bytes (read operations are not demarcated by
    // whitespace). In the fp case, except descriptor to have been opened in binary mode.
@@ -1061,12 +1071,11 @@ static inline char* _vl_vsss_read_bin(FILE* fp, int& floc, const WDataInP fromp,
    }
    return beginp;
 }
-static inline void _vl_vsss_setbit(WDataOutP owp, int obits, int lsb, int nbits,
-                                   IData ld) VL_MT_SAFE {
+static void _vl_vsss_setbit(WDataOutP owp, int obits, int lsb, int nbits, IData ld) VL_MT_SAFE {
    for (; nbits && lsb < obits; nbits--, lsb++, ld >>= 1) { VL_ASSIGNBIT_WI(lsb, owp, ld & 1); }
 }
-static inline void _vl_vsss_based(WDataOutP owp, int obits, int baseLog2, const char* strp,
-                                  size_t posstart, size_t posend) VL_MT_SAFE {
+static void _vl_vsss_based(WDataOutP owp, int obits, int baseLog2, const char* strp,
+                           size_t posstart, size_t posend) VL_MT_SAFE {
    // Read in base "2^^baseLog2" digits from strp[posstart..posend-1] into owp of size obits.
    int lsb = 0;
    for (int i = 0, pos = static_cast<int>(posend) - 1;
@@ -1183,7 +1192,7 @@ IData _vl_vsscanf(FILE* fp,  // If a fscanf
                    _vl_vsss_skipspace(fp, floc, fromp, fstr);
                    _vl_vsss_read_str(fp, floc, fromp, fstr, t_tmp, "0123456789+-xXzZ?_");
                    if (!t_tmp[0]) goto done;
-                    vlsint64_t ld = 0;
+                    int64_t ld = 0;
                    std::sscanf(t_tmp, "%30" PRId64, &ld);
                    VL_SET_WQ(owp, ld);
                    break;
@@ -1197,7 +1206,7 @@ IData _vl_vsscanf(FILE* fp,  // If a fscanf
                    // cppcheck-suppress unusedStructMember  // It's used
                    union {
                        double r;
-                        vlsint64_t ld;
+                        int64_t ld;
                    } u;
                    u.r = std::strtod(t_tmp, nullptr);
                    VL_SET_WQ(owp, u.ld);
@@ -1452,11 +1461,12 @@ void VL_SFORMAT_X(int obits, void* destp, const char* formatp, ...) VL_MT_SAFE {

 void VL_SFORMAT_X(int obits_ignored, std::string& output, const char* formatp, ...) VL_MT_SAFE {
    if (obits_ignored) {}
-    output = "";
+    std::string temp_output;
    va_list ap;
    va_start(ap, formatp);
-    _vl_vsformat(output, formatp, ap);
+    _vl_vsformat(temp_output, formatp, ap);
    va_end(ap);
+    output = temp_output;
 }

 std::string VL_SFORMATF_NX(const char* formatp, ...) VL_MT_SAFE {
@@ -1497,7 +1507,7 @@ void VL_FWRITEF(IData fpi, const char* formatp, ...) VL_MT_SAFE {
 IData VL_FSCANF_IX(IData fpi, const char* formatp, ...) VL_MT_SAFE {
    // While threadsafe, each thread can only access different file handles
    FILE* const fp = VL_CVT_I_FP(fpi);
-    if (VL_UNLIKELY(!fp)) return 0;
+    if (VL_UNLIKELY(!fp)) return ~0U;  // -1

    va_list ap;
    va_start(ap, formatp);
@@ -1605,8 +1615,8 @@ IData VL_SYSTEM_IW(int lhswords, const WDataInP lhsp) VL_MT_SAFE {
    return code >> 8;  // Want exit status
 }

-IData VL_TESTPLUSARGS_I(const char* formatp) VL_MT_SAFE {
-    const std::string& match = Verilated::threadContextp()->impp()->argPlusMatch(formatp);
+IData VL_TESTPLUSARGS_I(const std::string& format) VL_MT_SAFE {
+    const std::string& match = Verilated::threadContextp()->impp()->argPlusMatch(format.c_str());
    return match.empty() ? 0 : 1;
 }

@@ -1642,7 +1652,7 @@ IData VL_VALUEPLUSARGS_INW(int rbits, const std::string& ld, WDataOutP rwp) VL_M
    VL_ZERO_RESET_W(rbits, rwp);
    switch (std::tolower(fmt)) {
    case 'd': {
-        vlsint64_t lld = 0;
+        int64_t lld = 0;
        std::sscanf(dp, "%30" PRId64, &lld);
        VL_SET_WQ(rwp, lld);
        break;
@@ -1677,7 +1687,7 @@ IData VL_VALUEPLUSARGS_INW(int rbits, const std::string& ld, WDataOutP rwp) VL_M
        VL_SET_WQ(rwp, VL_CVT_Q_D(temp));
        break;
    }
-    default:  // Other simulators simply return 0 in these cases and don't error out
+    default:  // Other simulators return 0 in these cases and don't error out
        return 0;
    }
    _vl_clean_inplace_w(rbits, rwp);
@@ -1767,7 +1777,7 @@ std::string VL_CVT_PACK_STR_NW(int lwords, const WDataInP lwp) VL_MT_SAFE {

 std::string VL_PUTC_N(const std::string& lhs, IData rhs, CData ths) VL_PURE {
    std::string lstring = lhs;
-    const vlsint32_t rhs_s = rhs;  // To signed value
+    const int32_t rhs_s = rhs;  // To signed value
    // 6.16.2:str.putc(i, c) does not change the value when i < 0 || i >= str.len() || c == 0
    if (0 <= rhs_s && rhs < lhs.length() && ths != 0) lstring[rhs] = ths;
    return lstring;
@@ -1775,15 +1785,15 @@ std::string VL_PUTC_N(const std::string& lhs, IData rhs, CData ths) VL_PURE {

 CData VL_GETC_N(const std::string& lhs, IData rhs) VL_PURE {
    CData v = 0;
-    const vlsint32_t rhs_s = rhs;  // To signed value
+    const int32_t rhs_s = rhs;  // To signed value
    // 6.16.3:str.getc(i) returns 0 if i < 0 || i >= str.len()
    if (0 <= rhs_s && rhs < lhs.length()) v = lhs[rhs];
    return v;
 }

 std::string VL_SUBSTR_N(const std::string& lhs, IData rhs, IData ths) VL_PURE {
-    const vlsint32_t rhs_s = rhs;  // To signed value
-    const vlsint32_t ths_s = ths;  // To signed value
+    const int32_t rhs_s = rhs;  // To signed value
+    const int32_t ths_s = ths;  // To signed value
    // 6.16.8:str.substr(i, j) returns an empty string when i < 0 || j < i || j >= str.len()
    if (rhs_s < 0 || ths_s < rhs_s || ths >= lhs.length()) return "";
    // Second parameter of std::string::substr(i, n) is length, not position as in SystemVerilog
@@ -1822,7 +1832,7 @@ static const char* memhFormat(int nBits) {
    return t_buf;
 }

-static const char* formatBinary(int nBits, vluint32_t bits) {
+static const char* formatBinary(int nBits, uint32_t bits) {
    assert((nBits >= 1) && (nBits <= 32));

    static VL_THREAD_LOCAL char t_buf[64];
@@ -1839,12 +1849,11 @@ VlReadMem::VlReadMem(bool hex, int bits, const std::string& filename, QData star
    , m_bits{bits}
    , m_filename(filename)  // Need () or GCC 4.8 false warning
    , m_end{end}
-    , m_addr{start}
-    , m_linenum{0} {
+    , m_addr{start} {
    m_fp = std::fopen(filename.c_str(), "r");
    if (VL_UNLIKELY(!m_fp)) {
        // We don't report the Verilog source filename as it slow to have to pass it down
-        VL_FATAL_MT(filename.c_str(), 0, "", "$readmem file not found");
+        VL_WARN_MT(filename.c_str(), 0, "", "$readmem file not found");
        // cppcheck-suppress resourceLeak  // m_fp is nullptr - bug in cppcheck
        return;
    }
@@ -1974,8 +1983,7 @@ void VlReadMem::setData(void* valuep, const std::string& rhs) {

 VlWriteMem::VlWriteMem(bool hex, int bits, const std::string& filename, QData start, QData end)
    : m_hex{hex}
-    , m_bits{bits}
-    , m_addr{0} {
+    , m_bits{bits} {
    if (VL_UNLIKELY(start > end)) {
        VL_FATAL_MT(filename.c_str(), 0, "", "$writemem invalid address range");
        return;
@@ -2026,9 +2034,9 @@ void VlWriteMem::print(QData addr, bool addrstamp, const void* valuep) {
        }
    } else if (m_bits <= 64) {
        const QData* const datap = reinterpret_cast<const QData*>(valuep);
-        const vluint64_t value = VL_MASK_Q(m_bits) & *datap;
-        const vluint32_t lo = value & 0xffffffff;
-        const vluint32_t hi = value >> 32;
+        const uint64_t value = VL_MASK_Q(m_bits) & *datap;
+        const uint32_t lo = value & 0xffffffff;
+        const uint32_t hi = value >> 32;
        if (m_hex) {
            fprintf(m_fp, memhFormat(m_bits - 32), hi);
            fprintf(m_fp, "%08x\n", lo);
@@ -2157,29 +2165,6 @@ void VL_WRITEMEM_N(bool hex,  // Hex format, else binary
 //===========================================================================
 // Timescale conversion

-// Helper function for conversion of timescale strings
-// Converts (1|10|100)(s|ms|us|ns|ps|fs) to power of then
-int VL_TIME_STR_CONVERT(const char* strp) VL_PURE {
-    int scale = 0;
-    if (!strp) return 0;
-    if (*strp++ != '1') return 0;
-    while (*strp == '0') {
-        ++scale;
-        ++strp;
-    }
-    switch (*strp++) {
-    case 's': break;
-    case 'm': scale -= 3; break;
-    case 'u': scale -= 6; break;
-    case 'n': scale -= 9; break;
-    case 'p': scale -= 12; break;
-    case 'f': scale -= 15; break;
-    default: return 0;
-    }
-    if ((scale < 0) && (*strp++ != 's')) return 0;
-    if (*strp) return 0;
-    return scale;
-}
 static const char* vl_time_str(int scale) VL_PURE {
    static const char* const names[]
        = {"100s",  "10s",  "1s",  "100ms", "10ms", "1ms", "100us", "10us", "1us",
@@ -2234,8 +2219,8 @@ double vl_time_multiplier(int scale) VL_PURE {
        return pow10[scale];
    }
 }
-vluint64_t vl_time_pow10(int n) {
-    static const vluint64_t pow10[20] = {
+uint64_t vl_time_pow10(int n) {
+    static const uint64_t pow10[20] = {
        1ULL,
        10ULL,
        100ULL,
@@ -2279,7 +2264,7 @@ VerilatedContext::VerilatedContext()
    : m_impdatap{new VerilatedContextImpData} {
    Verilated::lastContextp(this);
    Verilated::threadContextp(this);
-    m_ns.m_profThreadsFilename = "profile_threads.dat";
+    m_ns.m_profExecFilename = "profile_exec.dat";
    m_ns.m_profVltFilename = "profile.vlt";
    m_fdps.resize(31);
    std::fill(m_fdps.begin(), m_fdps.end(), static_cast<FILE*>(nullptr));
@@ -2288,11 +2273,22 @@ VerilatedContext::VerilatedContext()
 }

 // Must declare here not in interface, as otherwise forward declarations not known
-VerilatedContext::~VerilatedContext() {}
+VerilatedContext::~VerilatedContext() {
+    checkMagic(this);
+    m_magic = 0x1;  // Arbitrary but 0x1 is what Verilator src uses for a deleted pointer
+}
+
+void VerilatedContext::checkMagic(const VerilatedContext* contextp) {
+    if (VL_UNLIKELY(!contextp || contextp->m_magic != MAGIC)) {
+        VL_FATAL_MT("", 0, "",  // LCOV_EXCL_LINE
+                    "Attempt to create model using a bad/deleted VerilatedContext pointer");
+    }
+}

 VerilatedContext::Serialized::Serialized() {
-    m_timeunit = VL_TIME_UNIT;  // Initial value until overriden by _Vconfigure
-    m_timeprecision = VL_TIME_PRECISION;  // Initial value until overriden by _Vconfigure
+    constexpr int8_t picosecond = -12;
+    m_timeunit = picosecond;  // Initial value until overriden by _Vconfigure
+    m_timeprecision = picosecond;  // Initial value until overriden by _Vconfigure
 }

 void VerilatedContext::assertOn(bool flag) VL_MT_SAFE {
@@ -2312,7 +2308,7 @@ std::string VerilatedContext::dumpfile() const VL_MT_SAFE_EXCLUDES(m_timeDumpMut
    return m_dumpfile;
 }
 std::string VerilatedContext::dumpfileCheck() const VL_MT_SAFE_EXCLUDES(m_timeDumpMutex) {
-    const std::string out = dumpfile();
+    std::string out = dumpfile();
    if (VL_UNLIKELY(out.empty())) {
        VL_PRINTF_MT("%%Warning: $dumpvar ignored as not proceeded by $dumpfile\n");
        return "";
@@ -2347,21 +2343,21 @@ void VerilatedContext::gotFinish(bool flag) VL_MT_SAFE {
    const VerilatedLockGuard lock{m_mutex};
    m_s.m_gotFinish = flag;
 }
-void VerilatedContext::profThreadsStart(vluint64_t flag) VL_MT_SAFE {
+void VerilatedContext::profExecStart(uint64_t flag) VL_MT_SAFE {
    const VerilatedLockGuard lock{m_mutex};
-    m_ns.m_profThreadsStart = flag;
+    m_ns.m_profExecStart = flag;
 }
-void VerilatedContext::profThreadsWindow(vluint64_t flag) VL_MT_SAFE {
+void VerilatedContext::profExecWindow(uint64_t flag) VL_MT_SAFE {
    const VerilatedLockGuard lock{m_mutex};
-    m_ns.m_profThreadsWindow = flag;
+    m_ns.m_profExecWindow = flag;
 }
-void VerilatedContext::profThreadsFilename(const std::string& flag) VL_MT_SAFE {
+void VerilatedContext::profExecFilename(const std::string& flag) VL_MT_SAFE {
    const VerilatedLockGuard lock{m_mutex};
-    m_ns.m_profThreadsFilename = flag;
+    m_ns.m_profExecFilename = flag;
 }
-std::string VerilatedContext::profThreadsFilename() const VL_MT_SAFE {
+std::string VerilatedContext::profExecFilename() const VL_MT_SAFE {
    const VerilatedLockGuard lock{m_mutex};
-    return m_ns.m_profThreadsFilename;
+    return m_ns.m_profExecFilename;
 }
 void VerilatedContext::profVltFilename(const std::string& flag) VL_MT_SAFE {
    const VerilatedLockGuard lock{m_mutex};
@@ -2417,6 +2413,33 @@ const char* VerilatedContext::timeprecisionString() const VL_MT_SAFE {
    return vl_time_str(timeprecision());
 }

+void VerilatedContext::threads(unsigned n) {
+    if (n == 0) VL_FATAL_MT(__FILE__, __LINE__, "", "%Error: Simulation threads must be >= 1");
+
+    if (m_threadPool) {
+        VL_FATAL_MT(
+            __FILE__, __LINE__, "",
+            "%Error: Cannot set simulation threads after the thread pool has been created.");
+    }
+
+#if VL_THREADED
+    if (m_threads == n) return;  // To avoid unnecessary warnings
+    m_threads = n;
+    const unsigned hardwareThreadsAvailable = std::thread::hardware_concurrency();
+    if (m_threads > hardwareThreadsAvailable) {
+        VL_PRINTF_MT("%%Warning: System has %u hardware threads but simulation thread count set "
+                     "to %u. This will likely cause significant slowdown.\n",
+                     hardwareThreadsAvailable, m_threads);
+    }
+#else
+    if (n > 1) {
+        VL_PRINTF_MT("%%Warning: Verilator run-time library built without VL_THREADS. Ignoring "
+                     "call to 'VerilatedContext::threads' with argument %u.\n",
+                     n);
+    }
+#endif
+}
+
 void VerilatedContext::commandArgs(int argc, const char** argv) VL_MT_SAFE_EXCLUDES(m_argMutex) {
    const VerilatedLockGuard lock{m_argMutex};
    m_args.m_argVec.clear();  // Empty first, then add
@@ -2447,6 +2470,33 @@ void VerilatedContext::internalsDump() const VL_MT_SAFE {
    VerilatedImp::userDump();
 }

+void VerilatedContext::addModel(VerilatedModel* modelp) {
+    threadPoolp();  // Ensure thread pool is created, so m_threads cannot change any more
+
+    if (modelp->threads() > m_threads) {
+        std::ostringstream msg;
+        msg << "VerilatedContext has " << m_threads << " threads but model '"
+            << modelp->modelName() << "' (instantiated as '" << modelp->hierName()
+            << "') was Verilated with --threads " << modelp->threads() << ".\n";
+        const std::string str = msg.str();
+        VL_FATAL_MT(__FILE__, __LINE__, modelp->hierName(), str.c_str());
+    }
+}
+
+VerilatedVirtualBase* VerilatedContext::threadPoolp() {
+    if (m_threads == 1) return nullptr;
+#if VL_THREADED
+    if (!m_threadPool) m_threadPool.reset(new VlThreadPool{this, m_threads - 1});
+#endif
+    return m_threadPool.get();
+}
+
+VerilatedVirtualBase*
+VerilatedContext::enableExecutionProfiler(VerilatedVirtualBase* (*construct)(VerilatedContext&)) {
+    if (!m_executionProfiler) m_executionProfiler.reset(construct(*this));
+    return m_executionProfiler.get();
+}
+
 //======================================================================
 // VerilatedContextImp:: Methods - command line

@@ -2506,13 +2556,16 @@ std::pair<int, char**> VerilatedContextImp::argc_argv() VL_MT_SAFE_EXCLUDES(m_ar

 void VerilatedContextImp::commandArgVl(const std::string& arg) {
    if (0 == std::strncmp(arg.c_str(), "+verilator+", std::strlen("+verilator+"))) {
-        std::string value;
+        std::string str;
+        uint64_t u64;
        if (arg == "+verilator+debug") {
            Verilated::debug(4);
-        } else if (commandArgVlValue(arg, "+verilator+debugi+", value /*ref*/)) {
-            Verilated::debug(std::atoi(value.c_str()));
-        } else if (commandArgVlValue(arg, "+verilator+error+limit+", value /*ref*/)) {
-            errorLimit(std::atoi(value.c_str()));
+        } else if (commandArgVlUint64(arg, "+verilator+debugi+", u64, 0,
+                                      std::numeric_limits<int>::max())) {
+            Verilated::debug(static_cast<int>(u64));
+        } else if (commandArgVlUint64(arg, "+verilator+error+limit+", u64, 0,
+                                      std::numeric_limits<int>::max())) {
+            errorLimit(static_cast<int>(u64));
        } else if (arg == "+verilator+help") {
            VerilatedImp::versionDump();
            VL_PRINTF_MT("For help, please see 'verilator --help'\n");
@@ -2520,18 +2573,22 @@ void VerilatedContextImp::commandArgVl(const std::string& arg) {
                        "Exiting due to command line argument (not an error)");
        } else if (arg == "+verilator+noassert") {
            assertOn(false);
-        } else if (commandArgVlValue(arg, "+verilator+prof+threads+start+", value /*ref*/)) {
-            profThreadsStart(std::atoll(value.c_str()));
-        } else if (commandArgVlValue(arg, "+verilator+prof+threads+window+", value /*ref*/)) {
-            profThreadsWindow(std::atol(value.c_str()));
-        } else if (commandArgVlValue(arg, "+verilator+prof+threads+file+", value /*ref*/)) {
-            profThreadsFilename(value);
-        } else if (commandArgVlValue(arg, "+verilator+prof+vlt+file+", value /*ref*/)) {
-            profVltFilename(value);
-        } else if (commandArgVlValue(arg, "+verilator+rand+reset+", value /*ref*/)) {
-            randReset(std::atoi(value.c_str()));
-        } else if (commandArgVlValue(arg, "+verilator+seed+", value /*ref*/)) {
-            randSeed(std::atoi(value.c_str()));
+        } else if (commandArgVlUint64(arg, "+verilator+prof+exec+start+", u64)
+                   || commandArgVlUint64(arg, "+verilator+prof+threads+start+", u64)) {
+            profExecStart(u64);
+        } else if (commandArgVlUint64(arg, "+verilator+prof+exec+window+", u64, 1)
+                   || commandArgVlUint64(arg, "+verilator+prof+threads+window+", u64, 1)) {
+            profExecWindow(u64);
+        } else if (commandArgVlString(arg, "+verilator+prof+exec+file+", str)
+                   || commandArgVlString(arg, "+verilator+prof+threads+file+", str)) {
+            profExecFilename(str);
+        } else if (commandArgVlString(arg, "+verilator+prof+vlt+file+", str)) {
+            profVltFilename(str);
+        } else if (commandArgVlUint64(arg, "+verilator+rand+reset+", u64, 0, 2)) {
+            randReset(static_cast<int>(u64));
+        } else if (commandArgVlUint64(arg, "+verilator+seed+", u64, 1,
+                                      std::numeric_limits<int>::max())) {
+            randSeed(static_cast<int>(u64));
        } else if (arg == "+verilator+V") {
            VerilatedImp::versionDump();  // Someday more info too
            VL_FATAL_MT("COMMAND_LINE", 0, "",
@@ -2541,12 +2598,14 @@ void VerilatedContextImp::commandArgVl(const std::string& arg) {
            VL_FATAL_MT("COMMAND_LINE", 0, "",
                        "Exiting due to command line argument (not an error)");
        } else {
-            VL_PRINTF_MT("%%Warning: Unknown +verilator runtime argument: '%s'\n", arg.c_str());
+            const std::string msg = "Unknown runtime argument: " + arg;
+            VL_FATAL_MT("COMMAND_LINE", 0, "", msg.c_str());
        }
    }
 }
-bool VerilatedContextImp::commandArgVlValue(const std::string& arg, const std::string& prefix,
-                                            std::string& valuer) {
+
+bool VerilatedContextImp::commandArgVlString(const std::string& arg, const std::string& prefix,
+                                             std::string& valuer) {
    const size_t len = prefix.length();
    if (0 == std::strncmp(prefix.c_str(), arg.c_str(), len)) {
        valuer = arg.substr(len);
@@ -2556,6 +2615,30 @@ bool VerilatedContextImp::commandArgVlValue(const std::string& arg, const std::s
    }
 }

+bool VerilatedContextImp::commandArgVlUint64(const std::string& arg, const std::string& prefix,
+                                             uint64_t& valuer, uint64_t min, uint64_t max) {
+    std::string str;
+    if (commandArgVlString(arg, prefix, str)) {
+        const auto fail = [&](const std::string& extra = "") {
+            std::stringstream ss;
+            ss << "Argument '" << prefix << "' must be an unsigned integer";
+            if (min != std::numeric_limits<uint64_t>::min()) ss << ", greater than " << min - 1;
+            if (max != std::numeric_limits<uint64_t>::max()) ss << ", less than " << max + 1;
+            if (!extra.empty()) ss << ". " << extra;
+            const std::string& msg = ss.str();
+            VL_FATAL_MT("COMMAND_LINE", 0, "", msg.c_str());
+        };
+
+        if (std::any_of(str.begin(), str.end(), [](int c) { return !std::isdigit(c); })) fail();
+        char* end;
+        valuer = std::strtoull(str.c_str(), &end, 10);
+        if (errno == ERANGE) fail("Value out of range of uint64_t");
+        if (valuer < min || valuer > max) fail();
+        return true;
+    }
+    return false;
+}
+
 //======================================================================
 // VerilatedContext:: + VerilatedContextImp:: Methods - random

@@ -2564,20 +2647,19 @@ void VerilatedContext::randSeed(int val) VL_MT_SAFE {
    // and so the rand seed's mutex must also be static
    const VerilatedLockGuard lock{VerilatedContextImp::s().s_randMutex};
    m_s.m_randSeed = val;
-    const vluint64_t newEpoch = VerilatedContextImp::s().s_randSeedEpoch + 1;
+    const uint64_t newEpoch = VerilatedContextImp::s().s_randSeedEpoch + 1;
    // Obververs must see new epoch AFTER seed updated
 #ifdef VL_THREADED
    std::atomic_signal_fence(std::memory_order_release);
 #endif
    VerilatedContextImp::s().s_randSeedEpoch = newEpoch;
 }
-vluint64_t VerilatedContextImp::randSeedDefault64() const VL_MT_SAFE {
+uint64_t VerilatedContextImp::randSeedDefault64() const VL_MT_SAFE {
    if (randSeed() != 0) {
-        return ((static_cast<vluint64_t>(randSeed()) << 32)
-                ^ (static_cast<vluint64_t>(randSeed())));
+        return ((static_cast<uint64_t>(randSeed()) << 32) ^ (static_cast<uint64_t>(randSeed())));
    } else {
-        return ((static_cast<vluint64_t>(vl_sys_rand32()) << 32)
-                ^ (static_cast<vluint64_t>(vl_sys_rand32())));
+        return ((static_cast<uint64_t>(vl_sys_rand32()) << 32)
+                ^ (static_cast<uint64_t>(vl_sys_rand32())));
    }
 }

@@ -2624,6 +2706,7 @@ const VerilatedScopeNameMap* VerilatedContext::scopeNameMap() VL_MT_SAFE {

 VerilatedSyms::VerilatedSyms(VerilatedContext* contextp)
    : _vm_contextp__(contextp ? contextp : Verilated::threadContextp()) {
+    VerilatedContext::checkMagic(_vm_contextp__);
    Verilated::threadContextp(_vm_contextp__);
 #ifdef VL_THREADED
    __Vm_evalMsgQp = new VerilatedEvalMsgQueue;
@@ -2631,6 +2714,7 @@ VerilatedSyms::VerilatedSyms(VerilatedContext* contextp)
 }

 VerilatedSyms::~VerilatedSyms() {
+    VerilatedContext::checkMagic(_vm_contextp__);
 #ifdef VL_THREADED
    delete __Vm_evalMsgQp;
 #endif
@@ -2722,7 +2806,7 @@ void Verilated::runFlushCallbacks() VL_MT_SAFE {
    // When running internal code coverage (gcc --coverage, as opposed to
    // verilator --coverage), dump coverage data to properly cover failing
    // tests.
-    VL_GCOV_FLUSH();
+    VL_GCOV_DUMP();
 }

 void Verilated::addExitCb(VoidPCb cb, void* datap) VL_MT_SAFE {
@@ -2805,6 +2889,14 @@ void VerilatedImp::versionDump() VL_MT_SAFE {
    VL_PRINTF_MT("  Version: %s %s\n", Verilated::productName(), Verilated::productVersion());
 }

+//===========================================================================
+// VerilatedModel:: Methods
+
+VerilatedModel::VerilatedModel(VerilatedContext& context)
+    : m_context{context} {}
+
+std::unique_ptr<VerilatedTraceConfig> VerilatedModel::traceConfig() const { return nullptr; }
+
 //===========================================================================
 // VerilatedModule:: Methods

@@ -2821,8 +2913,8 @@ VerilatedModule::~VerilatedModule() {
 // VerilatedVar:: Methods

 // cppcheck-suppress unusedFunction  // Used by applications
-vluint32_t VerilatedVarProps::entSize() const {
-    vluint32_t size = 1;
+uint32_t VerilatedVarProps::entSize() const {
+    uint32_t size = 1;
    switch (vltype()) {
    case VLVT_PTR: size = sizeof(void*); break;
    case VLVT_UINT8: size = sizeof(CData); break;
@@ -2845,7 +2937,7 @@ void* VerilatedVarProps::datapAdjustIndex(void* datap, int dim, int indx) const
    if (VL_UNLIKELY(dim <= 0 || dim > udims())) return nullptr;
    if (VL_UNLIKELY(indx < low(dim) || indx > high(dim))) return nullptr;
    const int indxAdj = indx - low(dim);
-    vluint8_t* bytep = reinterpret_cast<vluint8_t*>(datap);
+    uint8_t* bytep = reinterpret_cast<uint8_t*>(datap);
    // If on index 1 of a 2 index array, then each index 1 is index2sz*entsz
    size_t slicesz = entSize();
    for (int d = dim + 1; d <= m_udims; ++d) slicesz *= elements(d);
@@ -2866,7 +2958,7 @@ VerilatedScope::~VerilatedScope() {
 }

 void VerilatedScope::configure(VerilatedSyms* symsp, const char* prefixp, const char* suffixp,
-                               const char* identifier, vlsint8_t timeunit,
+                               const char* identifier, int8_t timeunit,
                               const Type& type) VL_MT_UNSAFE {
    // Slowpath - called once/scope at construction
    // We don't want the space and reference-count access overhead of strings.
@@ -33,6 +33,7 @@

 // clang-format off
 #include "verilatedos.h"
+#include "verilated_config.h"
 #if VM_SC
 # include "verilated_sc.h"  // Get SYSTEMC_VERSION and time declarations
 #endif
@@ -80,14 +81,19 @@
 #endif
 // clang-format on

+class VerilatedContext;
 class VerilatedContextImp;
 class VerilatedContextImpData;
 class VerilatedCovContext;
 class VerilatedEvalMsgQueue;
 class VerilatedFst;
 class VerilatedFstC;
+class VerilatedFstSc;
 class VerilatedScope;
 class VerilatedScopeNameMap;
+template <class, class>
+class VerilatedTrace;
+class VerilatedTraceConfig;
 class VerilatedVar;
 class VerilatedVarNameMap;
 class VerilatedVcd;
@@ -99,11 +105,11 @@ class VerilatedVcdSc;

 // clang-format off
 //    P                     // Packed data of bit type (C/S/I/Q/W)
-using CData = vluint8_t;    ///< Data representing 'bit' of 1-8 packed bits
-using SData = vluint16_t;   ///< Data representing 'bit' of 9-16 packed bits
-using IData = vluint32_t;   ///< Data representing 'bit' of 17-32 packed bits
-using QData = vluint64_t;   ///< Data representing 'bit' of 33-64 packed bits
-using EData = vluint32_t;   ///< Data representing one element of WData array
+using CData = uint8_t;    ///< Data representing 'bit' of 1-8 packed bits
+using SData = uint16_t;   ///< Data representing 'bit' of 9-16 packed bits
+using IData = uint32_t;   ///< Data representing 'bit' of 17-32 packed bits
+using QData = uint64_t;   ///< Data representing 'bit' of 33-64 packed bits
+using EData = uint32_t;   ///< Data representing one element of WData array
 using WData = EData;        ///< Data representing >64 packed bits (used as pointer)
 //    F     = float;        // No typedef needed; Verilator uses float
 //    D     = double;       // No typedef needed; Verilator uses double
@@ -113,7 +119,7 @@ using WData = EData;        ///< Data representing >64 packed bits (used as poin
 using WDataInP = const WData*;  ///< 'bit' of >64 packed bits as array input to a function
 using WDataOutP = WData*;  ///< 'bit' of >64 packed bits as array output from a function

-enum VerilatedVarType : vluint8_t {
+enum VerilatedVarType : uint8_t {
    VLVT_UNKNOWN = 0,
    VLVT_PTR,  // Pointer to something
    VLVT_UINT8,  // AKA CData
@@ -141,11 +147,11 @@ enum VerilatedVarFlags {
 // Mutex and threading support

 // Return current thread ID (or 0), not super fast, cache if needed
-extern vluint32_t VL_THREAD_ID() VL_MT_SAFE;
+extern uint32_t VL_THREAD_ID() VL_MT_SAFE;

 #if VL_THREADED

-#define VL_LOCK_SPINS 50000  /// Number of times to spin for a mutex before relaxing
+#define VL_LOCK_SPINS 50000  /// Number of times to spin for a mutex before yielding

 /// Mutex, wrapped to allow -fthread_safety checks
 class VL_CAPABILITY("mutex") VerilatedMutex final {
@@ -224,7 +230,7 @@ public:
 class VerilatedAssertOneThread final {
    // MEMBERS
 #if defined(VL_THREADED) && defined(VL_DEBUG)
-    vluint32_t m_threadid;  // Thread that is legal
+    uint32_t m_threadid;  // Thread that is legal
 public:
    // CONSTRUCTORS
    // The constructor establishes the thread id for all later calls.
@@ -250,6 +256,40 @@ public:
 #endif
 };

+//=========================================================================
+/// Base class of a Verilator generated (Verilated) model.
+///
+/// VerilatedModel is a base class of the user facing primary class generated
+/// by Verilator.
+
+class VerilatedModel VL_NOT_FINAL {
+    VL_UNCOPYABLE(VerilatedModel);
+
+    VerilatedContext& m_context;  // The VerilatedContext this model is instantiated under
+
+protected:
+    explicit VerilatedModel(VerilatedContext& context);
+    virtual ~VerilatedModel() = default;
+
+public:
+    /// Returns the VerilatedContext this model is instantiated under
+    /// Used to get to e.g. simulation time via contextp()->time()
+    VerilatedContext* contextp() const { return &m_context; }
+    /// Returns the hierarchical name of this module instance.
+    virtual const char* hierName() const = 0;
+    /// Returns the name of this model (the name of the generated model class).
+    virtual const char* modelName() const = 0;
+    /// Returns the thread level parallelism, this model was Verilated with. Always 1 or higher.
+    virtual unsigned threads() const = 0;
+
+private:
+    // The following are for use by Verilator internals only
+    template <class, class>
+    friend class VerilatedTrace;
+    // Run-time trace configuration requested by this model
+    virtual std::unique_ptr<VerilatedTraceConfig> traceConfig() const;
+};
+
 //=========================================================================
 /// Base class for all Verilated module classes.

@@ -264,10 +304,6 @@ public:
    const char* name() const { return m_namep; }  ///< Return name of module
 };

-/// Declare a module, ala SC_MODULE
-#define VL_MODULE(modname) class modname VL_NOT_FINAL : public VerilatedModule
-// Not class final in VL_MODULE, as users might be abstracting our models (--hierarchical)
-
 //=========================================================================
 // Functions overridable by user defines
 // (Internals however must use VL_PRINTF_MT, which calls these.)
@@ -318,10 +354,10 @@ protected:
        bool m_fatalOnVpiError = true;  // Fatal on vpi error/unsupported
        bool m_gotError = false;  // A $finish statement executed
        bool m_gotFinish = false;  // A $finish or $stop statement executed
-        vluint64_t m_time = 0;  // Current $time (unscaled), 0=at zero, or legacy
+        uint64_t m_time = 0;  // Current $time (unscaled), 0=at zero, or legacy
        // Slow path
-        vlsint8_t m_timeunit;  // Time unit as 0..15
-        vlsint8_t m_timeprecision;  // Time precision as 0..15
+        int8_t m_timeunit;  // Time unit as 0..15
+        int8_t m_timeprecision;  // Time precision as 0..15
        int m_errorCount = 0;  // Number of errors
        int m_errorLimit = 1;  // Stop on error number
        int m_randReset = 0;  // Random reset: 0=all 0s, 1=all 1s, 2=random
@@ -342,10 +378,10 @@ protected:
    struct NonSerialized {  // Non-serialized information
        // These are reloaded from on command-line settings, so do not need to persist
        // Fast path
-        vluint64_t m_profThreadsStart = 1;  // +prof+threads starting time
-        vluint32_t m_profThreadsWindow = 2;  // +prof+threads window size
+        uint64_t m_profExecStart = 1;  // +prof+exec+start time
+        uint32_t m_profExecWindow = 2;  // +prof+exec+window size
        // Slow path
-        std::string m_profThreadsFilename;  // +prof+threads filename
+        std::string m_profExecFilename;  // +prof+exec+file filename
        std::string m_profVltFilename;  // +prof+vlt filename
    } m_ns;

@@ -360,6 +396,16 @@ protected:

    // Implementation details
    const std::unique_ptr<VerilatedContextImpData> m_impdatap;
+    // Number of threads to use for simulation (size of m_threadPool + 1 for main thread)
+#ifdef VL_THREADED
+    unsigned m_threads = std::thread::hardware_concurrency();
+#else
+    const unsigned m_threads = 1;
+#endif
+    // The thread pool shared by all models added to this context
+    std::unique_ptr<VerilatedVirtualBase> m_threadPool;
+    // The execution profiler shared by all models added to this context
+    std::unique_ptr<VerilatedVirtualBase> m_executionProfiler;
    // Coverage access
    std::unique_ptr<VerilatedVirtualBase> m_coveragep;  // Pointer for coveragep()

@@ -372,6 +418,10 @@ protected:
    // List of free descriptors in the MCT region [4, 32)
    std::vector<IData> m_fdFreeMct VL_GUARDED_BY(m_fdMutex);

+    // Magic to check for bad construction
+    static constexpr uint64_t MAGIC = 0xC35F9A6E5298EE6EULL;  // SHA256 "VerilatedContext"
+    uint64_t m_magic = MAGIC;
+
 private:
    // CONSTRUCTORS
    VL_UNCOPYABLE(VerilatedContext);
@@ -407,9 +457,9 @@ public:
    VerilatedCovContext* coveragep() VL_MT_SAFE;
    /// Set debug level
    /// Debug is currently global, but for forward compatibility have a per-context method
-    static void debug(int val) VL_MT_SAFE;
+    static inline void debug(int val) VL_MT_SAFE;
    /// Return debug level
-    static int debug() VL_MT_SAFE;
+    static inline int debug() VL_MT_SAFE;
    /// Set current number of errors/assertions
    void errorCount(int val) VL_MT_SAFE;
    /// Increment current number of errors/assertions
@@ -466,16 +516,16 @@ public:
    /// timeInc, operating on the thread's context.
    ///
    /// * Else, if VL_TIME_STAMP64 is defined, time comes from the legacy
-    /// 'vluint64_t vl_time_stamp64()' which must a function be defined by
+    /// 'uint64_t vl_time_stamp64()' which must a function be defined by
    /// the user's wrapper.
    ///
    /// * Else, time comes from the legacy 'double sc_time_stamp()' which
    /// must be a function defined by the user's wrapper.
-    vluint64_t time() const VL_MT_SAFE;
+    inline uint64_t time() const VL_MT_SAFE;
    /// Set current simulation time. See time() for side effect details
-    void time(vluint64_t value) VL_MT_SAFE { m_s.m_time = value; }
+    void time(uint64_t value) VL_MT_SAFE { m_s.m_time = value; }
    /// Advance current simulation time. See time() for side effect details
-    void timeInc(vluint64_t add) VL_MT_UNSAFE { m_s.m_time += add; }
+    void timeInc(uint64_t add) VL_MT_UNSAFE { m_s.m_time += add; }
    /// Return time units as power-of-ten
    int timeunit() const VL_MT_SAFE { return -m_s.m_timeunit; }
    /// Set time units as power-of-ten
@@ -489,6 +539,12 @@ public:
    /// Get time precision as IEEE-standard text
    const char* timeprecisionString() const VL_MT_SAFE;

+    /// Get number of threads used for simulation (including the main thread)
+    unsigned threads() const { return m_threads; }
+    /// Set number of threads used for simulation (including the main thread)
+    /// Can only be called before the thread pool is created (before first model is added).
+    void threads(unsigned n);
+
    /// Allow traces to at some point be enabled (disables some optimizations)
    void traceEverOn(bool flag) VL_MT_SAFE {
        if (flag) calcUnusedSigs(true);
@@ -504,25 +560,32 @@ public:
    /// releases - contact the authors before production use.
    void scopesDump() const VL_MT_SAFE;

-public:  // But for internal use only
+    // METHODS - public but for internal use only
+
    // Internal: access to implementation class
    VerilatedContextImp* impp() { return reinterpret_cast<VerilatedContextImp*>(this); }
    const VerilatedContextImp* impp() const {
        return reinterpret_cast<const VerilatedContextImp*>(this);
    }

+    void addModel(VerilatedModel*);
+
+    VerilatedVirtualBase* threadPoolp();
+    VerilatedVirtualBase*
+    enableExecutionProfiler(VerilatedVirtualBase* (*construct)(VerilatedContext&));
+
    // Internal: $dumpfile
    void dumpfile(const std::string& flag) VL_MT_SAFE_EXCLUDES(m_timeDumpMutex);
    std::string dumpfile() const VL_MT_SAFE_EXCLUDES(m_timeDumpMutex);
    std::string dumpfileCheck() const VL_MT_SAFE_EXCLUDES(m_timeDumpMutex);

-    // Internal: --prof-threads related settings
-    void profThreadsStart(vluint64_t flag) VL_MT_SAFE;
-    vluint64_t profThreadsStart() const VL_MT_SAFE { return m_ns.m_profThreadsStart; }
-    void profThreadsWindow(vluint64_t flag) VL_MT_SAFE;
-    vluint32_t profThreadsWindow() const VL_MT_SAFE { return m_ns.m_profThreadsWindow; }
-    void profThreadsFilename(const std::string& flag) VL_MT_SAFE;
-    std::string profThreadsFilename() const VL_MT_SAFE;
+    // Internal: --prof-exec related settings
+    void profExecStart(uint64_t flag) VL_MT_SAFE;
+    uint64_t profExecStart() const VL_MT_SAFE { return m_ns.m_profExecStart; }
+    void profExecWindow(uint64_t flag) VL_MT_SAFE;
+    uint32_t profExecWindow() const VL_MT_SAFE { return m_ns.m_profExecWindow; }
+    void profExecFilename(const std::string& flag) VL_MT_SAFE;
+    std::string profExecFilename() const VL_MT_SAFE;
    void profVltFilename(const std::string& flag) VL_MT_SAFE;
    std::string profVltFilename() const VL_MT_SAFE;

@@ -533,6 +596,10 @@ public:  // But for internal use only
    // Internal: Serialization setup
    static constexpr size_t serialized1Size() VL_PURE { return sizeof(m_s); }
    void* serialized1Ptr() VL_MT_UNSAFE { return &m_s; }
+
+    // Internal: Check magic number
+    static void checkMagic(const VerilatedContext* contextp);
+    void selfTestClearMagic() { m_magic = 0x2; }
 };

 //===========================================================================
@@ -557,7 +624,7 @@ public:  // But for internal use only

 class VerilatedScope final {
 public:
-    enum Type : vluint8_t {
+    enum Type : uint8_t {
        SCOPE_MODULE,
        SCOPE_OTHER
    };  // Type of a scope, currently module is only interesting
@@ -570,28 +637,28 @@ private:
    VerilatedVarNameMap* m_varsp = nullptr;  // Variable map
    const char* m_namep = nullptr;  // Scope name (Slowpath)
    const char* m_identifierp = nullptr;  // Identifier of scope (with escapes removed)
-    vlsint8_t m_timeunit = 0;  // Timeunit in negative power-of-10
+    int8_t m_timeunit = 0;  // Timeunit in negative power-of-10
    Type m_type = SCOPE_OTHER;  // Type of the scope

 public:  // But internals only - called from VerilatedModule's
    VerilatedScope() = default;
    ~VerilatedScope();
    void configure(VerilatedSyms* symsp, const char* prefixp, const char* suffixp,
-                   const char* identifier, vlsint8_t timeunit, const Type& type) VL_MT_UNSAFE;
+                   const char* identifier, int8_t timeunit, const Type& type) VL_MT_UNSAFE;
    void exportInsert(int finalize, const char* namep, void* cb) VL_MT_UNSAFE;
    void varInsert(int finalize, const char* namep, void* datap, bool isParam,
                   VerilatedVarType vltype, int vlflags, int dims, ...) VL_MT_UNSAFE;
    // ACCESSORS
    const char* name() const { return m_namep; }
    const char* identifier() const { return m_identifierp; }
-    vlsint8_t timeunit() const { return m_timeunit; }
-    inline VerilatedSyms* symsp() const { return m_symsp; }
+    int8_t timeunit() const { return m_timeunit; }
+    VerilatedSyms* symsp() const { return m_symsp; }
    VerilatedVar* varFind(const char* namep) const VL_MT_SAFE_POSTINIT;
    VerilatedVarNameMap* varsp() const VL_MT_SAFE_POSTINIT { return m_varsp; }
    void scopeDump() const;
    void* exportFindError(int funcnum) const;
    static void* exportFindNullError(int funcnum) VL_MT_SAFE;
-    static inline void* exportFind(const VerilatedScope* scopep, int funcnum) VL_MT_SAFE {
+    static void* exportFind(const VerilatedScope* scopep, int funcnum) VL_MT_SAFE {
        if (VL_UNLIKELY(!scopep)) return exportFindNullError(funcnum);
        if (VL_LIKELY(funcnum < scopep->m_funcnumMax)) {
            // m_callbacksp must be declared, as Max'es are > 0
@@ -634,9 +701,9 @@ class Verilated final {
        // Fast path
        VerilatedContext* t_contextp = nullptr;  // Thread's context
 #ifdef VL_THREADED
-        vluint32_t t_mtaskId = 0;  // mtask# executing on this thread
+        uint32_t t_mtaskId = 0;  // mtask# executing on this thread
        // Messages maybe pending on thread, needs end-of-eval calls
-        vluint32_t t_endOfEvalReqd = 0;
+        uint32_t t_endOfEvalReqd = 0;
 #endif
        const VerilatedScope* t_dpiScopep = nullptr;  // DPI context scope
        const char* t_dpiFilename = nullptr;  // DPI context filename
@@ -660,7 +727,7 @@ public:
    /// Return debug level
    /// When multithreaded this may not immediately react to another thread
    /// changing the level (no mutex)
-    static inline int debug() VL_MT_SAFE { return s_debug; }
+    static int debug() VL_MT_SAFE { return s_debug; }
 #else
    /// Return constant 0 debug level, so C++'s optimizer rips up
    static constexpr int debug() VL_PURE { return 0; }
@@ -758,11 +825,11 @@ public:
    /// Return VerilatedContext::randSeed using current thread's VerilatedContext
    static int randSeed() VL_MT_SAFE { return Verilated::threadContextp()->randSeed(); }
    /// Call VerilatedContext::time using current thread's VerilatedContext
-    static void time(vluint64_t val) VL_MT_SAFE { Verilated::threadContextp()->time(val); }
+    static void time(uint64_t val) VL_MT_SAFE { Verilated::threadContextp()->time(val); }
    /// Return VerilatedContext::time using current thread's VerilatedContext
-    static vluint64_t time() VL_MT_SAFE { return Verilated::threadContextp()->time(); }
+    static uint64_t time() VL_MT_SAFE { return Verilated::threadContextp()->time(); }
    /// Call VerilatedContext::timeInc using current thread's VerilatedContext
-    static void timeInc(vluint64_t add) VL_MT_UNSAFE { Verilated::threadContextp()->timeInc(add); }
+    static void timeInc(uint64_t add) VL_MT_UNSAFE { Verilated::threadContextp()->timeInc(add); }
    // Deprecated
    static int timeunit() VL_MT_SAFE { return Verilated::threadContextp()->timeunit(); }
    static int timeprecision() VL_MT_SAFE { return Verilated::threadContextp()->timeprecision(); }
@@ -820,7 +887,6 @@ public:
    }
 #endif

-public:
    // METHODS - INTERNAL USE ONLY (but public due to what uses it)
    // Internal: Create a new module name by concatenating two strings
    // Returns pointer to thread-local static data (overwritten on next call)
@@ -848,8 +914,8 @@ public:
 #ifdef VL_THREADED
    // Internal: Set the mtaskId, called when an mtask starts
    // Per thread, so no need to be in VerilatedContext
-    static void mtaskId(vluint32_t id) VL_MT_SAFE { t_s.t_mtaskId = id; }
-    static vluint32_t mtaskId() VL_MT_SAFE { return t_s.t_mtaskId; }
+    static void mtaskId(uint32_t id) VL_MT_SAFE { t_s.t_mtaskId = id; }
+    static uint32_t mtaskId() VL_MT_SAFE { return t_s.t_mtaskId; }
    static void endOfEvalReqdInc() VL_MT_SAFE { ++t_s.t_endOfEvalReqd; }
    static void endOfEvalReqdDec() VL_MT_SAFE { --t_s.t_endOfEvalReqd; }

@@ -867,8 +933,8 @@ private:
 #endif
 };

-inline void VerilatedContext::debug(int val) VL_MT_SAFE { Verilated::debug(val); }
-inline int VerilatedContext::debug() VL_MT_SAFE { return Verilated::debug(); }
+void VerilatedContext::debug(int val) VL_MT_SAFE { Verilated::debug(val); }
+int VerilatedContext::debug() VL_MT_SAFE { return Verilated::debug(); }

 //=========================================================================
 // Data Types
@@ -56,6 +56,7 @@ VK_CPPFLAGS_ALWAYS += \
 		-DVM_SC=$(VM_SC) \
 		-DVM_TRACE=$(VM_TRACE) \
 		-DVM_TRACE_FST=$(VM_TRACE_FST) \
+		-DVM_TRACE_VCD=$(VM_TRACE_VCD) \
 		$(CFG_CXXFLAGS_NO_UNUSED) \

 ifeq ($(CFG_WITH_CCWARN),yes)	# Local... Else don't burden users
@@ -141,26 +142,6 @@ ifneq ($(VM_THREADS),0)
 endif
 endif

-ifneq ($(VM_TRACE_THREADS),0)
- ifneq ($(VM_TRACE_THREADS),)
-  ifeq ($(findstring -DVL_THREADED,$(CPPFLAGS)),)
-   $(error VM_TRACE_THREADS requires VM_THREADS)
-  endif
-  CPPFLAGS += -DVL_TRACE_THREADED
-  VK_C11=1
-  VK_LIBS_THREADED=1
- endif
-endif
-
-
-ifneq ($(VM_TRACE_FST_WRITER_THREAD),0)
- ifneq ($(VM_TRACE_FST_WRITER_THREAD),)
-  CPPFLAGS += -DVL_TRACE_FST_WRITER_THREAD
-  VK_C11=1
-  VK_LIBS_THREADED=1
- endif
-endif
-
 ifneq ($(VK_C11),0)
 ifneq ($(VK_C11),)
  # Need C++11 at least, so always default to newest
@@ -186,13 +167,17 @@ VM_SLOW += $(VM_CLASSES_SLOW) $(VM_SUPPORT_SLOW)
 VK_FAST_OBJS = $(addsuffix .o, $(VM_FAST))
 VK_SLOW_OBJS = $(addsuffix .o, $(VM_SLOW))

-VK_USER_OBJS   = $(addsuffix .o, $(VM_USER_CLASSES))
+VK_USER_OBJS = $(addsuffix .o, $(VM_USER_CLASSES))

 # Note VM_GLOBAL_FAST and VM_GLOBAL_SLOW holds the files required from the
 # run-time library. In practice everything is actually in VM_GLOBAL_FAST,
 # but keeping the distinction for compatibility for now.
 VK_GLOBAL_OBJS = $(addsuffix .o, $(VM_GLOBAL_FAST) $(VM_GLOBAL_SLOW))

+# Need to re-build if the generated makefile changes, as compiler options might
+# have changed.
+$(VK_GLOBAL_OBJS): $(VM_PREFIX).mk
+
 ifneq ($(VM_PARALLEL_BUILDS),1)
  # Fast build for small designs: All .cpp files in one fell swoop. This
  # saves total compute, but can be slower if only a little changes. It is
@@ -20,6 +20,11 @@
 // Autoconf substitutes this with the strings from AC_INIT.
 #define VERILATOR_PRODUCT "@PACKAGE_NAME@"

-/// Verilator version name, e.g. "1.000 2000-01-01"
+/// Verilator version name, e.g. "1.002 2000-01-01"
 // Autoconf substitutes this with the strings from AC_INIT.
 #define VERILATOR_VERSION "@PACKAGE_VERSION@"
+
+/// Verilator version number as integer
+/// As major * 100000 + minor * 1000, e.g. 1002000 == 1.002
+// Autoconf substitutes this with the strings from AC_INIT.
+#define VERILATOR_VERSION_INTEGER @VERILATOR_VERSION_INTEGER@
@@ -22,8 +22,10 @@
 //=============================================================================

 #include "verilatedos.h"
-#include "verilated.h"
+
 #include "verilated_cov.h"
+
+#include "verilated.h"
 #include "verilated_cov_key.h"

 #include <deque>
@@ -59,7 +61,7 @@ public:  // But only local to this file
        }
    }
    virtual ~VerilatedCovImpItem() = default;
-    virtual vluint64_t count() const = 0;
+    virtual uint64_t count() const = 0;
    virtual void zero() const = 0;
 };

@@ -69,22 +71,23 @@ public:  // But only local to this file
 // This isn't in the header file for auto-magic conversion because it
 // inlines to too much code and makes compilation too slow.

-template <class T> class VerilatedCoverItemSpec final : public VerilatedCovImpItem {
+template <class T>
+class VerilatedCoverItemSpec final : public VerilatedCovImpItem {
 private:
    // MEMBERS
    T* m_countp;  // Count value
 public:
    // METHODS
    // cppcheck-suppress truncLongCastReturn
-    virtual vluint64_t count() const override { return *m_countp; }
-    virtual void zero() const override { *m_countp = 0; }
+    uint64_t count() const override { return *m_countp; }
+    void zero() const override { *m_countp = 0; }
    // CONSTRUCTORS
    // cppcheck-suppress noExplicitConstructor
    explicit VerilatedCoverItemSpec(T* countp)
        : m_countp{countp} {
        *m_countp = 0;
    }
-    virtual ~VerilatedCoverItemSpec() override = default;
+    ~VerilatedCoverItemSpec() override = default;
 };

 //=============================================================================
@@ -103,7 +106,7 @@ private:
    using ItemList = std::deque<VerilatedCovImpItem*>;

    // MEMBERS
-    VerilatedMutex m_mutex;  // Protects all members
+    mutable VerilatedMutex m_mutex;  // Protects all members
    ValueIndexMap m_valueIndexes VL_GUARDED_BY(m_mutex);  // Unique arbitrary value for values
    IndexValueMap m_indexValues VL_GUARDED_BY(m_mutex);  // Unique arbitrary value for keys
    ItemList m_items VL_GUARDED_BY(m_mutex);  // List of all items
@@ -122,11 +125,7 @@ public:

 protected:
    friend class VerilatedCovContext;
-    virtual ~VerilatedCovImp() override { clearGuts(); }
-    static VerilatedCovImp& imp() VL_MT_SAFE {
-        static VerilatedCovImp s_singleton;
-        return s_singleton;
-    }
+    ~VerilatedCovImp() override { clearGuts(); }

 private:
    // PRIVATE METHODS
@@ -209,7 +208,7 @@ private:
        // Forward to . so we have a whole word
        const std::string suffix = *bpost ? std::string{bpost + 1} : "";

-        const std::string out = prefix + "*" + suffix;
+        std::string out = prefix + "*" + suffix;

        // cout << "\nch pre="<<prefix<<"  s="<<suffix<<"\nch a="<<old<<"\nch b="<<add
        // <<"\ncho="<<out<<endl;
@@ -372,7 +371,7 @@ public:
        os << "# SystemC::Coverage-3\n";

        // Build list of events; totalize if collapsing hierarchy
-        std::map<const std::string, std::pair<std::string, vluint64_t>> eventCounts;
+        std::map<const std::string, std::pair<std::string, uint64_t>> eventCounts;
        for (const auto& itemp : m_items) {
            std::string name;
            std::string hier;
@@ -439,11 +438,11 @@ void VerilatedCovContext::clearNonMatch(const char* matchp) VL_MT_SAFE {
 }
 void VerilatedCovContext::zero() VL_MT_SAFE { impp()->zero(); }
 void VerilatedCovContext::write(const char* filenamep) VL_MT_SAFE { impp()->write(filenamep); }
-void VerilatedCovContext::_inserti(vluint32_t* itemp) VL_MT_SAFE {
-    impp()->inserti(new VerilatedCoverItemSpec<vluint32_t>{itemp});
+void VerilatedCovContext::_inserti(uint32_t* itemp) VL_MT_SAFE {
+    impp()->inserti(new VerilatedCoverItemSpec<uint32_t>{itemp});
 }
-void VerilatedCovContext::_inserti(vluint64_t* itemp) VL_MT_SAFE {
-    impp()->inserti(new VerilatedCoverItemSpec<vluint64_t>{itemp});
+void VerilatedCovContext::_inserti(uint64_t* itemp) VL_MT_SAFE {
+    impp()->inserti(new VerilatedCoverItemSpec<uint64_t>{itemp});
 }
 void VerilatedCovContext::_insertf(const char* filename, int lineno) VL_MT_SAFE {
    impp()->insertf(filename, lineno);
@@ -515,8 +514,10 @@ VerilatedCovContext* VerilatedCov::threadCovp() VL_MT_SAFE {

 VerilatedCovContext* VerilatedContext::coveragep() VL_MT_SAFE {
    static VerilatedMutex s_mutex;
+    // cppcheck-suppress identicalInnerCondition
    if (VL_UNLIKELY(!m_coveragep)) {
        const VerilatedLockGuard lock{s_mutex};
+        // cppcheck-suppress identicalInnerCondition
        if (VL_LIKELY(!m_coveragep)) {  // Not redundant, prevents race
            m_coveragep.reset(new VerilatedCovImp);
        }
@@ -26,6 +26,7 @@
 #define VERILATOR_VERILATED_COV_H_

 #include "verilatedos.h"
+
 #include "verilated.h"

 #include <iostream>
@@ -72,7 +73,7 @@ class VerilatedCovImp;
 ///
 /// Example:
 ///
-///     vluint32_t m_cases[10];  // Storage for coverage data
+///     uint32_t m_cases[10];  // Storage for coverage data
 ///     constructor() {
 ///         // Initialize
 ///         for (int i = 0; i < 10; ++i) m_cases[i] = 0;
@@ -88,7 +89,8 @@ class VerilatedCovImp;
 //=============================================================================
 // Convert VL_COVER_INSERT value arguments to strings, is \internal

-template <class T> std::string vlCovCvtToStr(const T& t) VL_PURE {
+template <class T>
+std::string vlCovCvtToStr(const T& t) VL_PURE {
    std::ostringstream os;
    os << t;
    return os.str();
@@ -120,14 +122,15 @@ public:
    /// Zero coverage points
    void zero() VL_MT_SAFE;

-public:  // But Internal use only
+    // METHODS - public but Internal use only
+
    // Insert a coverage item
    // We accept from 1-30 key/value pairs, all as strings.
    // Call _insert1, followed by _insert2 and _insert3
    // Do not call directly; use VL_COVER_INSERT or higher level macros instead
    // _insert1: Remember item pointer with count.  (Not const, as may add zeroing function)
-    void _inserti(vluint32_t* itemp) VL_MT_SAFE;
-    void _inserti(vluint64_t* itemp) VL_MT_SAFE;
+    void _inserti(uint32_t* itemp) VL_MT_SAFE;
+    void _inserti(uint64_t* itemp) VL_MT_SAFE;
    // _insert2: Set default filename and line number
    void _insertf(const char* filename, int lineno) VL_MT_SAFE;
    // _insert3: Set parameters
@@ -157,8 +160,8 @@ protected:
    friend class VerilatedCovImp;
    // CONSTRUCTORS
    // Internal: Only made as part of VerilatedCovImp
-    VerilatedCovContext() {}
-    virtual ~VerilatedCovContext() {}
+    VerilatedCovContext() = default;
+    ~VerilatedCovContext() override = default;

    // METHODS
    // Internal: access to implementation class
@@ -28,7 +28,9 @@
 #define VERILATOR_VERILATED_DPI_CPP_

 #include "verilatedos.h"
+
 #include "verilated_dpi.h"
+
 #include "verilated_imp.h"

 // On MSVC++ we need svdpi.h to declare exports, not imports
@@ -179,7 +181,7 @@ void svPutPartselLogic(svLogicVecVal* dp, const svLogicVecVal s, int lbit, int w
 //======================================================================
 // Open array internals

-static inline const VerilatedDpiOpenVar* _vl_openhandle_varp(const svOpenArrayHandle h) {
+static const VerilatedDpiOpenVar* _vl_openhandle_varp(const svOpenArrayHandle h) {
    if (VL_UNLIKELY(!h)) {
        VL_FATAL_MT(__FILE__, __LINE__, "",
                    "%%Error: DPI svOpenArrayHandle function called with nullptr handle");
@@ -417,7 +419,7 @@ static void _vl_svPutBitArrElem(const svOpenArrayHandle d, svBit value, int narg
 }

 //======================================================================
-// DPI accessors that simply call above functions
+// DPI accessors that call above functions

 void* svGetArrElemPtr(const svOpenArrayHandle h, int indx1, ...) {
    const VerilatedDpiOpenVar* const varp = _vl_openhandle_varp(h);
@@ -27,6 +27,7 @@
 #define VERILATOR_VERILATED_DPI_H_

 #include "verilatedos.h"
+
 #include "verilated.h"  // Also presumably included by caller
 #include "verilated_sym_props.h"

@@ -28,7 +28,7 @@
 #include "verilated_fst_c.h"

 // GTKWave configuration
-#ifdef VL_TRACE_FST_WRITER_THREAD
+#ifdef VL_THREADED
 # define HAVE_LIBPTHREAD
 # define FST_WRITER_PARALLEL
 #endif
@@ -83,15 +83,16 @@ static_assert(static_cast<int>(FST_ST_VCD_PROGRAM) == static_cast<int>(VLT_TRACE
 //=============================================================================
 // Specialization of the generics for this trace format

-#define VL_DERIVED_T VerilatedFst
-#include "verilated_trace_imp.cpp"
-#undef VL_DERIVED_T
+#define VL_SUB_T VerilatedFst
+#define VL_BUF_T VerilatedFstBuffer
+#include "verilated_trace_imp.h"
+#undef VL_SUB_T
+#undef VL_BUF_T

 //=============================================================================
 // VerilatedFst

-VerilatedFst::VerilatedFst(void* fst)
-    : m_fst{fst} {}
+VerilatedFst::VerilatedFst(void* /*fst*/) {}

 VerilatedFst::~VerilatedFst() {
    if (m_fst) fstWriterClose(m_fst);
@@ -104,14 +105,12 @@ void VerilatedFst::open(const char* filename) VL_MT_SAFE_EXCLUDES(m_mutex) {
    m_fst = fstWriterCreate(filename, 1);
    fstWriterSetPackType(m_fst, FST_WR_PT_LZ4);
    fstWriterSetTimescaleFromString(m_fst, timeResStr().c_str());  // lintok-begin-on-ref
-#ifdef VL_TRACE_FST_WRITER_THREAD
-    fstWriterSetParallelMode(m_fst, 1);
-#endif
+    if (m_useFstWriterThread) fstWriterSetParallelMode(m_fst, 1);
    fullDump(true);  // First dump must be full for fst

    m_curScope.clear();

-    VerilatedTrace<VerilatedFst>::traceInit();
+    Super::traceInit();

    // Clear the scope stack
    auto it = m_curScope.begin();
@@ -122,7 +121,7 @@ void VerilatedFst::open(const char* filename) VL_MT_SAFE_EXCLUDES(m_mutex) {

    // convert m_code2symbol into an array for fast lookup
    if (!m_symbolp) {
-        m_symbolp = new fstHandle[nextCode()];
+        m_symbolp = new fstHandle[nextCode()]{0};
        for (const auto& i : m_code2symbol) m_symbolp[i.first] = i.second;
    }
    m_code2symbol.clear();
@@ -133,23 +132,23 @@ void VerilatedFst::open(const char* filename) VL_MT_SAFE_EXCLUDES(m_mutex) {

 void VerilatedFst::close() VL_MT_SAFE_EXCLUDES(m_mutex) {
    const VerilatedLockGuard lock{m_mutex};
-    VerilatedTrace<VerilatedFst>::closeBase();
+    Super::closeBase();
    fstWriterClose(m_fst);
    m_fst = nullptr;
 }

 void VerilatedFst::flush() VL_MT_SAFE_EXCLUDES(m_mutex) {
    const VerilatedLockGuard lock{m_mutex};
-    VerilatedTrace<VerilatedFst>::flushBase();
+    Super::flushBase();
    fstWriterFlushContext(m_fst);
 }

-void VerilatedFst::emitTimeChange(vluint64_t timeui) { fstWriterEmitTimeChange(m_fst, timeui); }
+void VerilatedFst::emitTimeChange(uint64_t timeui) { fstWriterEmitTimeChange(m_fst, timeui); }

 //=============================================================================
 // Decl

-void VerilatedFst::declDTypeEnum(int dtypenum, const char* name, vluint32_t elements,
+void VerilatedFst::declDTypeEnum(int dtypenum, const char* name, uint32_t elements,
                                 unsigned int minValbits, const char** itemNamesp,
                                 const char** itemValuesp) {
    const fstEnumHandle enumNum
@@ -157,11 +156,13 @@ void VerilatedFst::declDTypeEnum(int dtypenum, const char* name, vluint32_t elem
    m_local2fstdtype[dtypenum] = enumNum;
 }

-void VerilatedFst::declare(vluint32_t code, const char* name, int dtypenum, fstVarDir vardir,
-                           fstVarType vartype, bool array, int arraynum, int msb, int lsb) {
+void VerilatedFst::declare(uint32_t code, const char* name, int dtypenum, fstVarDir vardir,
+                           fstVarType vartype, bool array, int arraynum, bool bussed, int msb,
+                           int lsb) {
    const int bits = ((msb > lsb) ? (msb - lsb) : (lsb - msb)) + 1;

-    VerilatedTrace<VerilatedFst>::declCode(code, bits, false);
+    const bool enabled = Super::declCode(code, name, bits, false);
+    if (!enabled) return;

    std::string nameasstr = namePrefix() + name;
    std::istringstream nameiss{nameasstr};
@@ -205,6 +206,7 @@ void VerilatedFst::declare(vluint32_t code, const char* name, int dtypenum, fstV
    std::stringstream name_ss;
    name_ss << symbol_name;
    if (array) name_ss << "[" << arraynum << "]";
+    if (bussed) name_ss << " [" << msb << ":" << lsb << "]";
    std::string name_str = name_ss.str();

    if (dtypenum > 0) {
@@ -221,66 +223,108 @@ void VerilatedFst::declare(vluint32_t code, const char* name, int dtypenum, fstV
    }
 }

-void VerilatedFst::declBit(vluint32_t code, const char* name, int dtypenum, fstVarDir vardir,
+void VerilatedFst::declBit(uint32_t code, const char* name, int dtypenum, fstVarDir vardir,
                           fstVarType vartype, bool array, int arraynum) {
-    declare(code, name, dtypenum, vardir, vartype, array, arraynum, 0, 0);
+    declare(code, name, dtypenum, vardir, vartype, array, arraynum, false, 0, 0);
 }
-void VerilatedFst::declBus(vluint32_t code, const char* name, int dtypenum, fstVarDir vardir,
+void VerilatedFst::declBus(uint32_t code, const char* name, int dtypenum, fstVarDir vardir,
                           fstVarType vartype, bool array, int arraynum, int msb, int lsb) {
-    declare(code, name, dtypenum, vardir, vartype, array, arraynum, msb, lsb);
+    declare(code, name, dtypenum, vardir, vartype, array, arraynum, true, msb, lsb);
 }
-void VerilatedFst::declQuad(vluint32_t code, const char* name, int dtypenum, fstVarDir vardir,
+void VerilatedFst::declQuad(uint32_t code, const char* name, int dtypenum, fstVarDir vardir,
                            fstVarType vartype, bool array, int arraynum, int msb, int lsb) {
-    declare(code, name, dtypenum, vardir, vartype, array, arraynum, msb, lsb);
+    declare(code, name, dtypenum, vardir, vartype, array, arraynum, true, msb, lsb);
 }
-void VerilatedFst::declArray(vluint32_t code, const char* name, int dtypenum, fstVarDir vardir,
+void VerilatedFst::declArray(uint32_t code, const char* name, int dtypenum, fstVarDir vardir,
                             fstVarType vartype, bool array, int arraynum, int msb, int lsb) {
-    declare(code, name, dtypenum, vardir, vartype, array, arraynum, msb, lsb);
+    declare(code, name, dtypenum, vardir, vartype, array, arraynum, true, msb, lsb);
 }
-void VerilatedFst::declDouble(vluint32_t code, const char* name, int dtypenum, fstVarDir vardir,
+void VerilatedFst::declDouble(uint32_t code, const char* name, int dtypenum, fstVarDir vardir,
                              fstVarType vartype, bool array, int arraynum) {
-    declare(code, name, dtypenum, vardir, vartype, array, arraynum, 63, 0);
+    declare(code, name, dtypenum, vardir, vartype, array, arraynum, false, 63, 0);
 }

+//=============================================================================
+// Get/commit trace buffer
+
+VerilatedFst::Buffer* VerilatedFst::getTraceBuffer() {
+#ifdef VL_THREADED
+    if (offload()) return new OffloadBuffer{*this};
+#endif
+    return new Buffer{*this};
+}
+
+void VerilatedFst::commitTraceBuffer(VerilatedFst::Buffer* bufp) {
+#ifdef VL_THREADED
+    if (offload()) {
+        OffloadBuffer* const offloadBufferp = static_cast<OffloadBuffer*>(bufp);
+        if (offloadBufferp->m_offloadBufferWritep) {
+            m_offloadBufferWritep = offloadBufferp->m_offloadBufferWritep;
+            return;  // Buffer will be deleted by the offload thread
+        }
+    }
+#endif
+    delete bufp;
+}
+
+//=============================================================================
+// Configure
+
+void VerilatedFst::configure(const VerilatedTraceConfig& config) {
+    // If at least one model requests the FST writer thread, then use it
+    m_useFstWriterThread |= config.m_useFstWriterThread;
+}
+
+//=============================================================================
+// VerilatedFstBuffer implementation
+
+//=============================================================================
+// Trace rendering primitives
+
 // Note: emit* are only ever called from one place (full* in
-// verilated_trace_imp.cpp, which is included in this file at the top),
+// verilated_trace_imp.h, which is included in this file at the top),
 // so always inline them.

 VL_ATTR_ALWINLINE
-void VerilatedFst::emitBit(vluint32_t code, CData newval) {
+void VerilatedFstBuffer::emitBit(uint32_t code, CData newval) {
+    VL_DEBUG_IFDEF(assert(m_symbolp[code]););
    fstWriterEmitValueChange(m_fst, m_symbolp[code], newval ? "1" : "0");
 }

 VL_ATTR_ALWINLINE
-void VerilatedFst::emitCData(vluint32_t code, CData newval, int bits) {
+void VerilatedFstBuffer::emitCData(uint32_t code, CData newval, int bits) {
    char buf[VL_BYTESIZE];
+    VL_DEBUG_IFDEF(assert(m_symbolp[code]););
    cvtCDataToStr(buf, newval << (VL_BYTESIZE - bits));
    fstWriterEmitValueChange(m_fst, m_symbolp[code], buf);
 }

 VL_ATTR_ALWINLINE
-void VerilatedFst::emitSData(vluint32_t code, SData newval, int bits) {
+void VerilatedFstBuffer::emitSData(uint32_t code, SData newval, int bits) {
    char buf[VL_SHORTSIZE];
+    VL_DEBUG_IFDEF(assert(m_symbolp[code]););
    cvtSDataToStr(buf, newval << (VL_SHORTSIZE - bits));
    fstWriterEmitValueChange(m_fst, m_symbolp[code], buf);
 }

 VL_ATTR_ALWINLINE
-void VerilatedFst::emitIData(vluint32_t code, IData newval, int bits) {
+void VerilatedFstBuffer::emitIData(uint32_t code, IData newval, int bits) {
    char buf[VL_IDATASIZE];
+    VL_DEBUG_IFDEF(assert(m_symbolp[code]););
    cvtIDataToStr(buf, newval << (VL_IDATASIZE - bits));
    fstWriterEmitValueChange(m_fst, m_symbolp[code], buf);
 }

 VL_ATTR_ALWINLINE
-void VerilatedFst::emitQData(vluint32_t code, QData newval, int bits) {
+void VerilatedFstBuffer::emitQData(uint32_t code, QData newval, int bits) {
    char buf[VL_QUADSIZE];
+    VL_DEBUG_IFDEF(assert(m_symbolp[code]););
    cvtQDataToStr(buf, newval << (VL_QUADSIZE - bits));
    fstWriterEmitValueChange(m_fst, m_symbolp[code], buf);
 }

 VL_ATTR_ALWINLINE
-void VerilatedFst::emitWData(vluint32_t code, const WData* newvalp, int bits) {
+void VerilatedFstBuffer::emitWData(uint32_t code, const WData* newvalp, int bits) {
    int words = VL_WORDS_I(bits);
    char* wp = m_strbuf;
    // Convert the most significant word
@@ -296,6 +340,6 @@ void VerilatedFst::emitWData(vluint32_t code, const WData* newvalp, int bits) {
 }

 VL_ATTR_ALWINLINE
-void VerilatedFst::emitDouble(vluint32_t code, double newval) {
+void VerilatedFstBuffer::emitDouble(uint32_t code, double newval) {
    fstWriterEmitValueChange(m_fst, m_symbolp[code], &newval);
 }
@@ -31,60 +31,64 @@
 #include <string>
 #include <vector>

+class VerilatedFstBuffer;
+
 //=============================================================================
 // VerilatedFst
 // Base class to create a Verilator FST dump
 // This is an internally used class - see VerilatedFstC for what to call from applications

-class VerilatedFst final : public VerilatedTrace<VerilatedFst> {
+class VerilatedFst final : public VerilatedTrace<VerilatedFst, VerilatedFstBuffer> {
+public:
+    using Super = VerilatedTrace<VerilatedFst, VerilatedFstBuffer>;
+
 private:
-    // Give the superclass access to private bits (to avoid virtual functions)
-    friend class VerilatedTrace<VerilatedFst>;
+    friend VerilatedFstBuffer;  // Give the buffer access to the private bits

    //=========================================================================
    // FST specific internals

-    void* m_fst;
-    std::map<vluint32_t, fstHandle> m_code2symbol;
+    void* m_fst = nullptr;
+    std::map<uint32_t, fstHandle> m_code2symbol;
    std::map<int, fstEnumHandle> m_local2fstdtype;
    std::list<std::string> m_curScope;
    fstHandle* m_symbolp = nullptr;  // same as m_code2symbol, but as an array
    char* m_strbuf = nullptr;  // String buffer long enough to hold maxBits() chars

+    bool m_useFstWriterThread = false;  // Whether to use the separate FST writer thread
+
    // CONSTRUCTORS
    VL_UNCOPYABLE(VerilatedFst);
-    void declare(vluint32_t code, const char* name, int dtypenum, fstVarDir vardir,
-                 fstVarType vartype, bool array, int arraynum, int msb, int lsb);
+    void declare(uint32_t code, const char* name, int dtypenum, fstVarDir vardir,
+                 fstVarType vartype, bool array, int arraynum, bool bussed, int msb, int lsb);

 protected:
    //=========================================================================
    // Implementation of VerilatedTrace interface

-    // Implementations of protected virtual methods for VerilatedTrace
-    virtual void emitTimeChange(vluint64_t timeui) override;
+    // Called when the trace moves forward to a new time point
+    void emitTimeChange(uint64_t timeui) override;

    // Hooks called from VerilatedTrace
-    virtual bool preFullDump() override { return isOpen(); }
-    virtual bool preChangeDump() override { return isOpen(); }
+    bool preFullDump() override { return isOpen(); }
+    bool preChangeDump() override { return isOpen(); }

-    // Implementations of duck-typed methods for VerilatedTrace. These are
-    // called from only one place (namely full*) so always inline them.
-    inline void emitBit(vluint32_t code, CData newval);
-    inline void emitCData(vluint32_t code, CData newval, int bits);
-    inline void emitSData(vluint32_t code, SData newval, int bits);
-    inline void emitIData(vluint32_t code, IData newval, int bits);
-    inline void emitQData(vluint32_t code, QData newval, int bits);
-    inline void emitWData(vluint32_t code, const WData* newvalp, int bits);
-    inline void emitDouble(vluint32_t code, double newval);
+    // Trace buffer management
+    Buffer* getTraceBuffer() override;
+    void commitTraceBuffer(Buffer*) override;
+
+    // Configure sub-class
+    void configure(const VerilatedTraceConfig&) override;

 public:
    //=========================================================================
    // External interface to client code
-    // (All must be threadsafe)

+    // CONSTRUCTOR
    explicit VerilatedFst(void* fst = nullptr);
    ~VerilatedFst();

+    // METHODS - All must be thread safe
    // Open the file; call isOpen() to see if errors
    void open(const char* filename) VL_MT_SAFE_EXCLUDES(m_mutex);
    // Close the file
@@ -97,32 +101,75 @@ public:
    //=========================================================================
    // Internal interface to Verilator generated code

-    // Inside dumping routines, declare a data type
-    void declDTypeEnum(int dtypenum, const char* name, vluint32_t elements,
-                       unsigned int minValbits, const char** itemNamesp, const char** itemValuesp);
-
-    // Inside dumping routines, declare a signal
-    void declBit(vluint32_t code, const char* name, int dtypenum, fstVarDir vardir,
+    void declBit(uint32_t code, const char* name, int dtypenum, fstVarDir vardir,
                 fstVarType vartype, bool array, int arraynum);
-    void declBus(vluint32_t code, const char* name, int dtypenum, fstVarDir vardir,
+    void declBus(uint32_t code, const char* name, int dtypenum, fstVarDir vardir,
                 fstVarType vartype, bool array, int arraynum, int msb, int lsb);
-    void declQuad(vluint32_t code, const char* name, int dtypenum, fstVarDir vardir,
+    void declQuad(uint32_t code, const char* name, int dtypenum, fstVarDir vardir,
                  fstVarType vartype, bool array, int arraynum, int msb, int lsb);
-    void declArray(vluint32_t code, const char* name, int dtypenum, fstVarDir vardir,
+    void declArray(uint32_t code, const char* name, int dtypenum, fstVarDir vardir,
                   fstVarType vartype, bool array, int arraynum, int msb, int lsb);
-    void declDouble(vluint32_t code, const char* name, int dtypenum, fstVarDir vardir,
+    void declDouble(uint32_t code, const char* name, int dtypenum, fstVarDir vardir,
                    fstVarType vartype, bool array, int arraynum);
+
+    void declDTypeEnum(int dtypenum, const char* name, uint32_t elements, unsigned int minValbits,
+                       const char** itemNamesp, const char** itemValuesp);
 };

 #ifndef DOXYGEN
 // Declare specialization here as it's used in VerilatedFstC just below
-template <> void VerilatedTrace<VerilatedFst>::dump(vluint64_t timeui);
-template <> void VerilatedTrace<VerilatedFst>::set_time_unit(const char* unitp);
-template <> void VerilatedTrace<VerilatedFst>::set_time_unit(const std::string& unit);
-template <> void VerilatedTrace<VerilatedFst>::set_time_resolution(const char* unitp);
-template <> void VerilatedTrace<VerilatedFst>::set_time_resolution(const std::string& unit);
+template <>
+void VerilatedFst::Super::dump(uint64_t time);
+template <>
+void VerilatedFst::Super::set_time_unit(const char* unitp);
+template <>
+void VerilatedFst::Super::set_time_unit(const std::string& unit);
+template <>
+void VerilatedFst::Super::set_time_resolution(const char* unitp);
+template <>
+void VerilatedFst::Super::set_time_resolution(const std::string& unit);
+template <>
+void VerilatedFst::Super::dumpvars(int level, const std::string& hier);
 #endif

+//=============================================================================
+// VerilatedFstBuffer
+
+class VerilatedFstBuffer VL_NOT_FINAL {
+    // Give the trace file access to the private bits
+    friend VerilatedFst;
+    friend VerilatedFst::Super;
+    friend VerilatedFst::Buffer;
+    friend VerilatedFst::OffloadBuffer;
+
+    VerilatedFst& m_owner;  // Trace file owning this buffer. Required by subclasses.
+
+    // The FST file handle
+    void* const m_fst = m_owner.m_fst;
+    // code to fstHande map, as an array
+    const fstHandle* const m_symbolp = m_owner.m_symbolp;
+    // String buffer long enough to hold maxBits() chars
+    char* const m_strbuf = m_owner.m_strbuf;
+
+    // CONSTRUCTOR
+    explicit VerilatedFstBuffer(VerilatedFst& owner)
+        : m_owner{owner} {}
+    virtual ~VerilatedFstBuffer() = default;
+
+    //=========================================================================
+    // Implementation of VerilatedTraceBuffer interface
+
+    // Implementations of duck-typed methods for VerilatedTraceBuffer. These are
+    // called from only one place (the full* methods), so always inline them.
+    VL_ATTR_ALWINLINE void emitBit(uint32_t code, CData newval);
+    VL_ATTR_ALWINLINE void emitCData(uint32_t code, CData newval, int bits);
+    VL_ATTR_ALWINLINE void emitSData(uint32_t code, SData newval, int bits);
+    VL_ATTR_ALWINLINE void emitIData(uint32_t code, IData newval, int bits);
+    VL_ATTR_ALWINLINE void emitQData(uint32_t code, QData newval, int bits);
+    VL_ATTR_ALWINLINE void emitWData(uint32_t code, const WData* newvalp, int bits);
+    VL_ATTR_ALWINLINE void emitDouble(uint32_t code, double newval);
+};
+
 //=============================================================================
 // VerilatedFstC
 /// Create a FST dump file in C standalone (no SystemC) simulations.
@@ -154,12 +201,12 @@ public:
    /// Write one cycle of dump data
    /// Call with the current context's time just after eval'ed,
    /// e.g. ->dump(contextp->time())
-    void dump(vluint64_t timeui) { m_sptrace.dump(timeui); }
+    void dump(uint64_t timeui) { m_sptrace.dump(timeui); }
    /// Write one cycle of dump data - backward compatible and to reduce
-    /// conversion warnings.  It's better to use a vluint64_t time instead.
-    void dump(double timestamp) { dump(static_cast<vluint64_t>(timestamp)); }
-    void dump(vluint32_t timestamp) { dump(static_cast<vluint64_t>(timestamp)); }
-    void dump(int timestamp) { dump(static_cast<vluint64_t>(timestamp)); }
+    /// conversion warnings.  It's better to use a uint64_t time instead.
+    void dump(double timestamp) { dump(static_cast<uint64_t>(timestamp)); }
+    void dump(uint32_t timestamp) { dump(static_cast<uint64_t>(timestamp)); }
+    void dump(int timestamp) { dump(static_cast<uint64_t>(timestamp)); }

    // METHODS - Internal/backward compatible
    // \protectedsection
@@ -178,9 +225,14 @@ public:
    void set_time_resolution(const std::string& unit) VL_MT_SAFE {
        m_sptrace.set_time_resolution(unit);
    }
+    // Set variables to dump, using $dumpvars format
+    // If level = 0, dump everything and hier is then ignored
+    void dumpvars(int level, const std::string& hier) VL_MT_SAFE {
+        m_sptrace.dumpvars(level, hier);
+    }

    // Internal class access
-    inline VerilatedFst* spTrace() { return &m_sptrace; }
+    VerilatedFst* spTrace() { return &m_sptrace; }
 };

 #endif  // guard
@@ -22,6 +22,7 @@
 //=============================================================================

 #include "verilatedos.h"
+
 #include "verilated_fst_sc.h"

 //======================================================================
@@ -30,7 +31,7 @@
 void VerilatedFstSc::open(const char* filename) {
    if (!sc_core::sc_get_curr_simcontext()->elaboration_done()) {
        vl_fatal(__FILE__, __LINE__, "VerilatedFstSc",
-                 ("%Error: VerilatedFstSc::open(\"" + std::string(filename)
+                 ("%Error: VerilatedFstSc::open(\"" + std::string{filename}
                  + "\") is called before sc_core::sc_start(). "
                    "Run sc_core::sc_start(sc_core::SC_ZERO_TIME) before opening a wave file.")
                     .c_str());
@@ -63,9 +64,6 @@ void VerilatedFstSc::trace(const unsigned int&, const std::string&, const char**
    DECL_TRACE_METHOD_B( unsigned short )
    DECL_TRACE_METHOD_B( unsigned int )
    DECL_TRACE_METHOD_B( unsigned long )
-#ifdef SYSTEMC_64BIT_PATCHES
-    DECL_TRACE_METHOD_B( unsigned long long)
-#endif
    DECL_TRACE_METHOD_B( char )
    DECL_TRACE_METHOD_B( short )
    DECL_TRACE_METHOD_B( int )
@@ -23,8 +23,9 @@
 #define _VERILATED_FST_SC_H_ 1

 #include "verilatedos.h"
-#include "verilated_sc.h"
+
 #include "verilated_fst_c.h"
+#include "verilated_sc.h"

 #include <string>

@@ -51,34 +52,35 @@ public:
        }
        spTrace()->set_time_resolution(sc_get_time_resolution().to_string());
    }
-    virtual ~VerilatedFstSc() { close(); }
+    ~VerilatedFstSc() override { close(); }

    // METHODS
    /// Called by SystemC simulate()
-    virtual void cycle(bool delta_cycle) {
+    void cycle(bool delta_cycle) override {
        if (!delta_cycle) { this->dump(sc_time_stamp().to_double()); }
    }

    // Override VerilatedFstC. Must be called after starting simulation.
-    virtual void open(const char* filename) /*override*/ VL_MT_SAFE;
+    // Note: this is not a virtual function in the base class, so no 'override'
+    virtual void open(const char* filename) VL_MT_SAFE;

 private:
    /// Fake outs for linker

 #ifdef NC_SYSTEMC
    // Cadence Incisive has these as abstract functions so we must create them
-    virtual void set_time_unit(int exponent10_seconds) {}  // deprecated
+    void set_time_unit(int exponent10_seconds) override {}  // deprecated
 #endif
-    virtual void set_time_unit(double v, sc_time_unit tu) {}  // LCOV_EXCL_LINE
+    void set_time_unit(double v, sc_time_unit tu) override {}  // LCOV_EXCL_LINE

 //--------------------------------------------------
 // SystemC 2.1.v1
-#define DECL_TRACE_METHOD_A(tp) virtual void trace(const tp& object, const std::string& name);
+#define DECL_TRACE_METHOD_A(tp) void trace(const tp& object, const std::string& name) override;
 #define DECL_TRACE_METHOD_B(tp) \
-    virtual void trace(const tp& object, const std::string& name, int width);
+    void trace(const tp& object, const std::string& name, int width) override;

-    virtual void write_comment(const std::string&);
-    virtual void trace(const unsigned int&, const std::string&, const char**);
+    void write_comment(const std::string&) override;
+    void trace(const unsigned int&, const std::string&, const char**) override;

    // clang-format off
    // Formatting matches that of sc_trace.h
@@ -95,9 +97,6 @@ private:
    DECL_TRACE_METHOD_B( unsigned short )
    DECL_TRACE_METHOD_B( unsigned int )
    DECL_TRACE_METHOD_B( unsigned long )
-#ifdef SYSTEMC_64BIT_PATCHES
-    DECL_TRACE_METHOD_B( unsigned long long)
-#endif
    DECL_TRACE_METHOD_B( char )
    DECL_TRACE_METHOD_B( short )
    DECL_TRACE_METHOD_B( int )
@@ -90,7 +90,7 @@ extern WDataOutP VL_RANDOM_W(int obits, WDataOutP outwp);
 extern IData VL_RANDOM_SEEDED_II(IData& seedr) VL_MT_SAFE;
 extern IData VL_URANDOM_SEEDED_II(IData seed) VL_MT_SAFE;
 inline IData VL_URANDOM_RANGE_I(IData hi, IData lo) {
-    const vluint64_t rnd = vl_rand64();
+    const uint64_t rnd = vl_rand64();
    if (VL_LIKELY(hi > lo)) {
        // (hi - lo + 1) can be zero when hi is UINT_MAX and lo is zero
        if (VL_UNLIKELY(hi - lo + 1 == 0)) return rnd;
@@ -112,15 +112,6 @@ extern WDataOutP VL_RAND_RESET_W(int obits, WDataOutP outwp);
 /// Zero reset a signal (slow - else use VL_ZERO_W)
 extern WDataOutP VL_ZERO_RESET_W(int obits, WDataOutP outwp);

-#if VL_THREADED
-/// Return high-precision counter for profiling, or 0x0 if not available
-inline QData VL_RDTSC_Q() {
-    vluint64_t val;
-    VL_RDTSC(val);
-    return val;
-}
-#endif
-
 extern void VL_PRINTTIMESCALE(const char* namep, const char* timeunitp,
                              const VerilatedContext* contextp) VL_MT_SAFE;

@@ -155,17 +146,13 @@ extern IData VL_SYSTEM_IW(int lhswords, WDataInP const lhsp);
 extern IData VL_SYSTEM_IQ(QData lhs);
 inline IData VL_SYSTEM_II(IData lhs) VL_MT_SAFE { return VL_SYSTEM_IQ(lhs); }

-extern IData VL_TESTPLUSARGS_I(const char* formatp);
+extern IData VL_TESTPLUSARGS_I(const std::string& format);
 extern const char* vl_mc_scan_plusargs(const char* prefixp);  // PLIish

 //=========================================================================
 // Base macros

 // Return true if data[bit] set; not 0/1 return, but 0/non-zero return.
-#define VL_BITISSET_I(data, bit) ((data) & (VL_UL(1) << VL_BITBIT_I(bit)))
-#define VL_BITISSET_Q(data, bit) ((data) & (1ULL << VL_BITBIT_Q(bit)))
-#define VL_BITISSET_E(data, bit) ((data) & (VL_EUL(1) << VL_BITBIT_E(bit)))
-#define VL_BITISSET_W(data, bit) ((data)[VL_BITWORD_E(bit)] & (VL_EUL(1) << VL_BITBIT_E(bit)))
 #define VL_BITISSETLIMIT_W(data, width, bit) (((bit) < (width)) && VL_BITISSET_W(data, bit))

 // Shift appropriate word by bit. Does not account for wrapping between two words
@@ -223,29 +210,27 @@ static inline QData VL_CVT_Q_D(double lhs) VL_PURE {
 // Return double from lhs (numeric) unsigned
 double VL_ITOR_D_W(int lbits, WDataInP const lwp) VL_PURE;
 static inline double VL_ITOR_D_I(int, IData lhs) VL_PURE {
-    return static_cast<double>(static_cast<vluint32_t>(lhs));
+    return static_cast<double>(static_cast<uint32_t>(lhs));
 }
 static inline double VL_ITOR_D_Q(int, QData lhs) VL_PURE {
-    return static_cast<double>(static_cast<vluint64_t>(lhs));
+    return static_cast<double>(static_cast<uint64_t>(lhs));
 }
 // Return double from lhs (numeric) signed
 double VL_ISTOR_D_W(int lbits, WDataInP const lwp) VL_PURE;
 static inline double VL_ISTOR_D_I(int lbits, IData lhs) VL_PURE {
-    if (lbits == 32) return static_cast<double>(static_cast<vlsint32_t>(lhs));
+    if (lbits == 32) return static_cast<double>(static_cast<int32_t>(lhs));
    VlWide<VL_WQ_WORDS_E> lwp;
    VL_SET_WI(lwp, lhs);
    return VL_ISTOR_D_W(lbits, lwp);
 }
 static inline double VL_ISTOR_D_Q(int lbits, QData lhs) VL_PURE {
-    if (lbits == 64) return static_cast<double>(static_cast<vlsint64_t>(lhs));
+    if (lbits == 64) return static_cast<double>(static_cast<int64_t>(lhs));
    VlWide<VL_WQ_WORDS_E> lwp;
    VL_SET_WQ(lwp, lhs);
    return VL_ISTOR_D_W(lbits, lwp);
 }
 // Return QData from double (numeric)
-static inline IData VL_RTOI_I_D(double lhs) VL_PURE {
-    return static_cast<vlsint32_t>(VL_TRUNC(lhs));
-}
+static inline IData VL_RTOI_I_D(double lhs) VL_PURE { return static_cast<int32_t>(VL_TRUNC(lhs)); }

 // Sign extend such that if MSB set, we get ffff_ffff, else 0s
 // (Requires clean input)
@@ -271,51 +256,33 @@ extern void _vl_debug_print_w(int lbits, WDataInP const iwp);
 //=========================================================================
 // Pli macros

-extern int VL_TIME_STR_CONVERT(const char* strp) VL_PURE;
-
-// These are deprecated and used only to establish the default precision/units.
-// Use Verilator timescale-override for better control.
 // clang-format off
-#ifndef VL_TIME_PRECISION
-# ifdef VL_TIME_PRECISION_STR
-#  define VL_TIME_PRECISION VL_TIME_STR_CONVERT(VL_STRINGIFY(VL_TIME_PRECISION_STR))
-# else
-#  define VL_TIME_PRECISION (-12)  ///< Timescale default units if not in Verilog - picoseconds
-# endif
-#endif
-#ifndef VL_TIME_UNIT
-# ifdef VL_TIME_UNIT_STR
-#  define VL_TIME_UNIT VL_TIME_STR_CONVERT(VL_STRINGIFY(VL_TIME_PRECISION_STR))
-# else
-#  define VL_TIME_UNIT (-12)  ///< Timescale default units if not in Verilog - picoseconds
-# endif
-#endif

 #if defined(SYSTEMC_VERSION)
 /// Return current simulation time
 // Already defined: extern sc_time sc_time_stamp();
-inline vluint64_t vl_time_stamp64() { return sc_time_stamp().value(); }
+inline uint64_t vl_time_stamp64() { return sc_time_stamp().value(); }
 #else  // Non-SystemC
 # if !defined(VL_TIME_CONTEXT) && !defined(VL_NO_LEGACY)
 #  ifdef VL_TIME_STAMP64
 // vl_time_stamp64() may be optionally defined by the user to return time.
 // On MSVC++ weak symbols are not supported so must be declared, or define
 // VL_TIME_CONTEXT.
-extern vluint64_t vl_time_stamp64() VL_ATTR_WEAK;
+extern uint64_t vl_time_stamp64() VL_ATTR_WEAK;
 #  else
 // sc_time_stamp() may be optionally defined by the user to return time.
 // On MSVC++ weak symbols are not supported so must be declared, or define
 // VL_TIME_CONTEXT.
 extern double sc_time_stamp() VL_ATTR_WEAK;  // Verilator 4.032 and newer
-inline vluint64_t vl_time_stamp64() {
+inline uint64_t vl_time_stamp64() {
    // clang9.0.1 requires & although we really do want the weak symbol value
-    return VL_LIKELY(&sc_time_stamp) ? static_cast<vluint64_t>(sc_time_stamp()) : 0;
+    return VL_LIKELY(&sc_time_stamp) ? static_cast<uint64_t>(sc_time_stamp()) : 0;
 }
 #  endif
 # endif
 #endif

-inline vluint64_t VerilatedContext::time() const VL_MT_SAFE {
+uint64_t VerilatedContext::time() const VL_MT_SAFE {
    // When using non-default context, fastest path is return time
    if (VL_LIKELY(m_s.m_time)) return m_s.m_time;
 #if defined(SYSTEMC_VERSION) || (!defined(VL_TIME_CONTEXT) && !defined(VL_NO_LEGACY))
@@ -340,16 +307,22 @@ inline vluint64_t VerilatedContext::time() const VL_MT_SAFE {
 // Return time precision as multiplier of time units
 double vl_time_multiplier(int scale) VL_PURE;
 // Return power of 10. e.g. returns 100 if n==2
-vluint64_t vl_time_pow10(int n) VL_PURE;
+uint64_t vl_time_pow10(int n) VL_PURE;

 #ifdef VL_DEBUG
-/// Evaluate statement if Verilated::debug() enabled
+/// Evaluate statement if VL_DEBUG defined
+# define VL_DEBUG_IFDEF(stmt) \
+    do { \
+        stmt \
+    } while (false)
+/// Evaluate statement if VL_DEBUG defined and Verilated::debug() enabled
 # define VL_DEBUG_IF(stmt) \
    do { \
        if (VL_UNLIKELY(Verilated::debug())) {stmt} \
    } while (false)
 #else
 // We intentionally do not compile the stmt to improve compile speed
+# define VL_DEBUG_IFDEF(stmt) do {} while (false)
 # define VL_DEBUG_IF(stmt) do {} while (false)
 #endif

@@ -475,10 +448,17 @@ static inline void VL_ASSIGNBIT_WO(int bit, WDataOutP owp) VL_MT_SAFE {
    { \
        const int words = VL_WORDS_I(obits); \
        sc_biguint<(obits)> _butemp = (svar).read(); \
-        for (int i = 0; i < words; ++i) { \
-            int msb = ((i + 1) * VL_IDATASIZE) - 1; \
-            msb = (msb >= (obits)) ? ((obits)-1) : msb; \
-            (owp)[i] = _butemp.range(msb, i * VL_IDATASIZE).to_uint(); \
+        uint32_t* chunk = _butemp.get_raw(); \
+        int32_t lsb = 0; \
+        while (lsb < obits - BITS_PER_DIGIT) { \
+            const uint32_t data = *chunk; \
+            ++chunk; \
+            _vl_insert_WI(owp.data(), data, lsb + BITS_PER_DIGIT - 1, lsb); \
+            lsb += BITS_PER_DIGIT; \
+        } \
+        if (lsb < obits) { \
+            const uint32_t msb_data = *chunk; \
+            _vl_insert_WI(owp.data(), msb_data, obits - 1, lsb); \
        } \
        (owp)[words - 1] &= VL_MASK_E(obits); \
    }
@@ -519,13 +499,23 @@ static inline void VL_ASSIGNBIT_WO(int bit, WDataOutP owp) VL_MT_SAFE {
    { (svar).write(rd); }
 #define VL_ASSIGN_SBQ(obits, svar, rd) \
    { (svar).write(rd); }
+#define VL_SC_BITS_PER_DIGIT 30  // This comes from sc_nbdefs.h BITS_PER_DIGIT
 #define VL_ASSIGN_SBW(obits, svar, rwp) \
    { \
        sc_biguint<(obits)> _butemp; \
-        for (int i = 0; i < VL_WORDS_I(obits); ++i) { \
-            int msb = ((i + 1) * VL_IDATASIZE) - 1; \
-            msb = (msb >= (obits)) ? ((obits)-1) : msb; \
-            _butemp.range(msb, i* VL_IDATASIZE) = (rwp)[i]; \
+        int32_t lsb = 0; \
+        uint32_t* chunk = _butemp.get_raw(); \
+        while (lsb + VL_SC_BITS_PER_DIGIT < (obits)) { \
+            static_assert(std::is_same<IData, EData>::value, "IData and EData missmatch"); \
+            const uint32_t data = VL_SEL_IWII(lsb + VL_SC_BITS_PER_DIGIT + 1, (rwp).data(), lsb, \
+                                              VL_SC_BITS_PER_DIGIT); \
+            *chunk = data & VL_MASK_E(VL_SC_BITS_PER_DIGIT); \
+            ++chunk; \
+            lsb += VL_SC_BITS_PER_DIGIT; \
+        } \
+        if (lsb < (obits)) { \
+            const uint32_t msb_data = VL_SEL_IWII((obits) + 1, (rwp).data(), lsb, (obits)-lsb); \
+            *chunk = msb_data & VL_MASK_E((obits)-lsb); \
        } \
        (svar).write(_butemp); \
    }
@@ -880,46 +870,46 @@ static inline int _vl_cmp_w(int words, WDataInP const lwp, WDataInP const rwp) V
 static inline IData VL_GTS_III(int lbits, IData lhs, IData rhs) VL_PURE {
    // For lbits==32, this becomes just a single instruction, otherwise ~5.
    // GCC 3.3.4 sign extension bugs on AMD64 architecture force us to use quad logic
-    const vlsint64_t lhs_signed = VL_EXTENDS_QQ(64, lbits, lhs);  // Q for gcc
-    const vlsint64_t rhs_signed = VL_EXTENDS_QQ(64, lbits, rhs);  // Q for gcc
+    const int64_t lhs_signed = VL_EXTENDS_QQ(64, lbits, lhs);  // Q for gcc
+    const int64_t rhs_signed = VL_EXTENDS_QQ(64, lbits, rhs);  // Q for gcc
    return lhs_signed > rhs_signed;
 }
 static inline IData VL_GTS_IQQ(int lbits, QData lhs, QData rhs) VL_PURE {
-    const vlsint64_t lhs_signed = VL_EXTENDS_QQ(64, lbits, lhs);
-    const vlsint64_t rhs_signed = VL_EXTENDS_QQ(64, lbits, rhs);
+    const int64_t lhs_signed = VL_EXTENDS_QQ(64, lbits, lhs);
+    const int64_t rhs_signed = VL_EXTENDS_QQ(64, lbits, rhs);
    return lhs_signed > rhs_signed;
 }

 static inline IData VL_GTES_III(int lbits, IData lhs, IData rhs) VL_PURE {
-    const vlsint64_t lhs_signed = VL_EXTENDS_QQ(64, lbits, lhs);  // Q for gcc
-    const vlsint64_t rhs_signed = VL_EXTENDS_QQ(64, lbits, rhs);  // Q for gcc
+    const int64_t lhs_signed = VL_EXTENDS_QQ(64, lbits, lhs);  // Q for gcc
+    const int64_t rhs_signed = VL_EXTENDS_QQ(64, lbits, rhs);  // Q for gcc
    return lhs_signed >= rhs_signed;
 }
 static inline IData VL_GTES_IQQ(int lbits, QData lhs, QData rhs) VL_PURE {
-    const vlsint64_t lhs_signed = VL_EXTENDS_QQ(64, lbits, lhs);
-    const vlsint64_t rhs_signed = VL_EXTENDS_QQ(64, lbits, rhs);
+    const int64_t lhs_signed = VL_EXTENDS_QQ(64, lbits, lhs);
+    const int64_t rhs_signed = VL_EXTENDS_QQ(64, lbits, rhs);
    return lhs_signed >= rhs_signed;
 }

 static inline IData VL_LTS_III(int lbits, IData lhs, IData rhs) VL_PURE {
-    const vlsint64_t lhs_signed = VL_EXTENDS_QQ(64, lbits, lhs);  // Q for gcc
-    const vlsint64_t rhs_signed = VL_EXTENDS_QQ(64, lbits, rhs);  // Q for gcc
+    const int64_t lhs_signed = VL_EXTENDS_QQ(64, lbits, lhs);  // Q for gcc
+    const int64_t rhs_signed = VL_EXTENDS_QQ(64, lbits, rhs);  // Q for gcc
    return lhs_signed < rhs_signed;
 }
 static inline IData VL_LTS_IQQ(int lbits, QData lhs, QData rhs) VL_PURE {
-    const vlsint64_t lhs_signed = VL_EXTENDS_QQ(64, lbits, lhs);
-    const vlsint64_t rhs_signed = VL_EXTENDS_QQ(64, lbits, rhs);
+    const int64_t lhs_signed = VL_EXTENDS_QQ(64, lbits, lhs);
+    const int64_t rhs_signed = VL_EXTENDS_QQ(64, lbits, rhs);
    return lhs_signed < rhs_signed;
 }

 static inline IData VL_LTES_III(int lbits, IData lhs, IData rhs) VL_PURE {
-    const vlsint64_t lhs_signed = VL_EXTENDS_QQ(64, lbits, lhs);  // Q for gcc
-    const vlsint64_t rhs_signed = VL_EXTENDS_QQ(64, lbits, rhs);  // Q for gcc
+    const int64_t lhs_signed = VL_EXTENDS_QQ(64, lbits, lhs);  // Q for gcc
+    const int64_t rhs_signed = VL_EXTENDS_QQ(64, lbits, rhs);  // Q for gcc
    return lhs_signed <= rhs_signed;
 }
 static inline IData VL_LTES_IQQ(int lbits, QData lhs, QData rhs) VL_PURE {
-    const vlsint64_t lhs_signed = VL_EXTENDS_QQ(64, lbits, lhs);
-    const vlsint64_t rhs_signed = VL_EXTENDS_QQ(64, lbits, rhs);
+    const int64_t lhs_signed = VL_EXTENDS_QQ(64, lbits, lhs);
+    const int64_t rhs_signed = VL_EXTENDS_QQ(64, lbits, rhs);
    return lhs_signed <= rhs_signed;
 }

@@ -1013,13 +1003,13 @@ static inline WDataOutP VL_MUL_W(int words, WDataOutP owp, WDataInP const lwp,
 }

 static inline IData VL_MULS_III(int lbits, IData lhs, IData rhs) VL_PURE {
-    const vlsint32_t lhs_signed = VL_EXTENDS_II(32, lbits, lhs);
-    const vlsint32_t rhs_signed = VL_EXTENDS_II(32, lbits, rhs);
+    const int32_t lhs_signed = VL_EXTENDS_II(32, lbits, lhs);
+    const int32_t rhs_signed = VL_EXTENDS_II(32, lbits, rhs);
    return lhs_signed * rhs_signed;
 }
 static inline QData VL_MULS_QQQ(int lbits, QData lhs, QData rhs) VL_PURE {
-    const vlsint64_t lhs_signed = VL_EXTENDS_QQ(64, lbits, lhs);
-    const vlsint64_t rhs_signed = VL_EXTENDS_QQ(64, lbits, rhs);
+    const int64_t lhs_signed = VL_EXTENDS_QQ(64, lbits, lhs);
+    const int64_t rhs_signed = VL_EXTENDS_QQ(64, lbits, rhs);
    return lhs_signed * rhs_signed;
 }

@@ -1065,30 +1055,30 @@ static inline IData VL_DIVS_III(int lbits, IData lhs, IData rhs) VL_PURE {
    if (VL_UNLIKELY(rhs == 0)) return 0;
    // -MAX / -1 cannot be represented in twos complement, and will cause SIGFPE
    if (VL_UNLIKELY(lhs == 0x80000000 && rhs == 0xffffffff)) return 0;
-    const vlsint32_t lhs_signed = VL_EXTENDS_II(VL_IDATASIZE, lbits, lhs);
-    const vlsint32_t rhs_signed = VL_EXTENDS_II(VL_IDATASIZE, lbits, rhs);
+    const int32_t lhs_signed = VL_EXTENDS_II(VL_IDATASIZE, lbits, lhs);
+    const int32_t rhs_signed = VL_EXTENDS_II(VL_IDATASIZE, lbits, rhs);
    return lhs_signed / rhs_signed;
 }
 static inline QData VL_DIVS_QQQ(int lbits, QData lhs, QData rhs) VL_PURE {
    if (VL_UNLIKELY(rhs == 0)) return 0;
    // -MAX / -1 cannot be represented in twos complement, and will cause SIGFPE
    if (VL_UNLIKELY(lhs == 0x8000000000000000ULL && rhs == 0xffffffffffffffffULL)) return 0;
-    const vlsint64_t lhs_signed = VL_EXTENDS_QQ(VL_QUADSIZE, lbits, lhs);
-    const vlsint64_t rhs_signed = VL_EXTENDS_QQ(VL_QUADSIZE, lbits, rhs);
+    const int64_t lhs_signed = VL_EXTENDS_QQ(VL_QUADSIZE, lbits, lhs);
+    const int64_t rhs_signed = VL_EXTENDS_QQ(VL_QUADSIZE, lbits, rhs);
    return lhs_signed / rhs_signed;
 }
 static inline IData VL_MODDIVS_III(int lbits, IData lhs, IData rhs) VL_PURE {
    if (VL_UNLIKELY(rhs == 0)) return 0;
    if (VL_UNLIKELY(lhs == 0x80000000 && rhs == 0xffffffff)) return 0;
-    const vlsint32_t lhs_signed = VL_EXTENDS_II(VL_IDATASIZE, lbits, lhs);
-    const vlsint32_t rhs_signed = VL_EXTENDS_II(VL_IDATASIZE, lbits, rhs);
+    const int32_t lhs_signed = VL_EXTENDS_II(VL_IDATASIZE, lbits, lhs);
+    const int32_t rhs_signed = VL_EXTENDS_II(VL_IDATASIZE, lbits, rhs);
    return lhs_signed % rhs_signed;
 }
 static inline QData VL_MODDIVS_QQQ(int lbits, QData lhs, QData rhs) VL_PURE {
    if (VL_UNLIKELY(rhs == 0)) return 0;
    if (VL_UNLIKELY(lhs == 0x8000000000000000ULL && rhs == 0xffffffffffffffffULL)) return 0;
-    const vlsint64_t lhs_signed = VL_EXTENDS_QQ(VL_QUADSIZE, lbits, lhs);
-    const vlsint64_t rhs_signed = VL_EXTENDS_QQ(VL_QUADSIZE, lbits, rhs);
+    const int64_t lhs_signed = VL_EXTENDS_QQ(VL_QUADSIZE, lbits, lhs);
+    const int64_t rhs_signed = VL_EXTENDS_QQ(VL_QUADSIZE, lbits, rhs);
    return lhs_signed % rhs_signed;
 }

@@ -1419,8 +1409,8 @@ static inline IData VL_STREAML_FAST_III(int lbits, IData ld, IData rd_log2) VL_P
    //   ret = 10324---
    IData ret = ld;
    if (rd_log2) {
-        const vluint32_t lbitsFloor = lbits & ~VL_MASK_I(rd_log2);  // max multiple of rd <= lbits
-        const vluint32_t lbitsRem = lbits - lbitsFloor;  // number of bits in most-sig slice (MSS)
+        const uint32_t lbitsFloor = lbits & ~VL_MASK_I(rd_log2);  // max multiple of rd <= lbits
+        const uint32_t lbitsRem = lbits - lbitsFloor;  // number of bits in most-sig slice (MSS)
        const IData msbMask = VL_MASK_I(lbitsRem) << lbitsFloor;  // mask to sel only bits in MSS
        ret = (ret & ~msbMask) | ((ret & msbMask) << ((VL_UL(1) << rd_log2) - lbitsRem));
    }
@@ -1439,8 +1429,8 @@ static inline QData VL_STREAML_FAST_QQI(int lbits, QData ld, IData rd_log2) VL_P
    // Pre-shift bits in most-significant slice (see comment in VL_STREAML_FAST_III)
    QData ret = ld;
    if (rd_log2) {
-        const vluint32_t lbitsFloor = lbits & ~VL_MASK_I(rd_log2);
-        const vluint32_t lbitsRem = lbits - lbitsFloor;
+        const uint32_t lbitsFloor = lbits & ~VL_MASK_I(rd_log2);
+        const uint32_t lbitsRem = lbits - lbitsFloor;
        const QData msbMask = lbitsFloor == 64 ? 0ULL : VL_MASK_Q(lbitsRem) << lbitsFloor;
        ret = (ret & ~msbMask) | ((ret & msbMask) << ((1ULL << rd_log2) - lbitsRem));
    }
@@ -1938,8 +1928,8 @@ static inline QData VL_RTOIROUND_Q_D(double lhs) VL_PURE {
    if (lhs == 0.0) return 0;
    const QData q = VL_CVT_Q_D(lhs);
    const int lsb = static_cast<int>((q >> 52ULL) & VL_MASK_Q(11)) - 1023 - 52;
-    const vluint64_t mantissa = (q & VL_MASK_Q(52)) | (1ULL << 52);
-    vluint64_t out = 0;
+    const uint64_t mantissa = (q & VL_MASK_Q(52)) | (1ULL << 52);
+    uint64_t out = 0;
    if (lsb < 0) {
        out = mantissa >> -lsb;
    } else if (lsb < 64) {
@@ -1959,7 +1949,7 @@ static inline WDataOutP VL_RTOIROUND_W_D(int obits, WDataOutP owp, double lhs) V
    if (lhs == 0.0) return owp;
    const QData q = VL_CVT_Q_D(lhs);
    const int lsb = static_cast<int>((q >> 52ULL) & VL_MASK_Q(11)) - 1023 - 52;
-    const vluint64_t mantissa = (q & VL_MASK_Q(52)) | (1ULL << 52);
+    const uint64_t mantissa = (q & VL_MASK_Q(52)) | (1ULL << 52);
    if (lsb < 0) {
        VL_SET_WQ(owp, mantissa >> -lsb);
    } else if (lsb < obits) {
@@ -34,6 +34,7 @@

 #include <algorithm>
 #include <deque>
+#include <limits>
 #include <map>
 #include <numeric>
 #include <set>
@@ -64,7 +65,7 @@ public:

 private:
    // MEMBERS
-    vluint32_t m_mtaskId;  // MTask that did enqueue
+    uint32_t m_mtaskId;  // MTask that did enqueue
    std::function<void()> m_cb;  // Lambda to execute when message received
 public:
    // CONSTRUCTORS
@@ -77,7 +78,7 @@ public:
    VerilatedMsg& operator=(const VerilatedMsg&) = default;
    VerilatedMsg& operator=(VerilatedMsg&&) = default;
    // METHODS
-    vluint32_t mtaskId() const { return m_mtaskId; }
+    uint32_t mtaskId() const { return m_mtaskId; }
    // Execute the lambda function
    void run() const { m_cb(); }
 };
@@ -88,9 +89,9 @@ public:
 class VerilatedEvalMsgQueue final {
    using VerilatedThreadQueue = std::multiset<VerilatedMsg, VerilatedMsg::Cmp>;

-    std::atomic<vluint64_t> m_depth;  // Current depth of queue (see comments below)
+    std::atomic<uint64_t> m_depth;  // Current depth of queue (see comments below)

-    VerilatedMutex m_mutex;  // Mutex protecting queue
+    mutable VerilatedMutex m_mutex;  // Mutex protecting queue
    VerilatedThreadQueue m_queue VL_GUARDED_BY(m_mutex);  // Message queue
 public:
    // CONSTRUCTORS
@@ -142,11 +143,10 @@ class VerilatedThreadMsgQueue final {

 public:
    // CONSTRUCTORS
-    VerilatedThreadMsgQueue() {}
-    ~VerilatedThreadMsgQueue() {
-        // The only call of this with a non-empty queue is a fatal error.
-        // So this does not flush the queue, as the destination queue is not known to this class.
-    }
+    VerilatedThreadMsgQueue() = default;
+    ~VerilatedThreadMsgQueue() = default;
+    // The only call of destructor with a non-empty queue is a fatal error.
+    // So this does not flush the queue, as the destination queue is not known to this class.

 private:
    VL_UNCOPYABLE(VerilatedThreadMsgQueue);
@@ -187,11 +187,11 @@ class VerilatedFpList final {

 public:
    using const_iterator = FILE* const*;
-    explicit VerilatedFpList() {}
+    explicit VerilatedFpList() = default;
    const_iterator begin() const { return m_fp; }
    const_iterator end() const { return m_fp + m_sz; }
    std::size_t size() const { return m_sz; }
-    std::size_t capacity() const { return 31; }
+    static std::size_t capacity() { return 31; }
    void push_back(FILE* fd) {
        if (VL_LIKELY(size() < capacity())) m_fp[m_sz++] = fd;
    }
@@ -235,17 +235,16 @@ class VerilatedContextImp final : VerilatedContext {
        return s_s;
    }

-private:
+public:  // But only for verilated*.cpp
    // CONSTRUCTORS - no data can live here, use only VerilatedContext
    VerilatedContextImp() = delete;
    ~VerilatedContextImp() = delete;

-public:  // But only for verilated*.cpp
    // METHODS - extending into VerilatedContext, call via impp()->

    // Random seed handling
-    vluint64_t randSeedDefault64() const VL_MT_SAFE;
-    static vluint32_t randSeedEpoch() VL_MT_SAFE { return s().s_randSeedEpoch; }
+    uint64_t randSeedDefault64() const VL_MT_SAFE;
+    static uint32_t randSeedEpoch() VL_MT_SAFE { return s().s_randSeedEpoch; }

    // METHODS - timeformat
    int timeFormatUnits() const VL_MT_SAFE {
@@ -271,13 +270,12 @@ public:  // But only for verilated*.cpp
    std::string argPlusMatch(const char* prefixp) VL_MT_SAFE_EXCLUDES(m_argMutex);
    std::pair<int, char**> argc_argv() VL_MT_SAFE_EXCLUDES(m_argMutex);

-public:  // But only for verilated*.cpp
-    // METHODS - scope name
+    // METHODS - scope name - INTERNAL only for verilated*.cpp
    void scopeInsert(const VerilatedScope* scopep) VL_MT_SAFE;
    void scopeErase(const VerilatedScope* scopep) VL_MT_SAFE;

-public:  // But only for verilated*.cpp
-    // METHODS - file IO
+    // METHODS - file IO - INTERNAL only for verilated*.cpp
+
    IData fdNewMcd(const char* filenamep) VL_MT_SAFE_EXCLUDES(m_fdMutex) {
        const VerilatedLockGuard lock{m_fdMutex};
        if (m_fdFreeMct.empty()) return 0;
@@ -297,7 +295,7 @@ public:  // But only for verilated*.cpp
            const std::size_t start = std::max<std::size_t>(31UL + 1UL + 3UL, m_fdps.size());
            const std::size_t excess = 10;
            m_fdps.resize(start + excess);
-            std::fill(m_fdps.begin() + start, m_fdps.end(), (FILE*)0);
+            std::fill(m_fdps.begin() + start, m_fdps.end(), static_cast<FILE*>(nullptr));
            m_fdFree.resize(excess);
            for (std::size_t i = 0, id = start; i < m_fdFree.size(); ++i, ++id) {
                m_fdFree[i] = id;
@@ -316,14 +314,14 @@ public:  // But only for verilated*.cpp
    IData fdSeek(IData fdi, IData offset, IData origin) VL_MT_SAFE_EXCLUDES(m_fdMutex) {
        const VerilatedLockGuard lock{m_fdMutex};
        const VerilatedFpList fdlist = fdToFpList(fdi);
-        if (VL_UNLIKELY(fdlist.size() != 1)) return 0;
+        if (VL_UNLIKELY(fdlist.size() != 1)) return ~0U;  // -1
        return static_cast<IData>(
            std::fseek(*fdlist.begin(), static_cast<long>(offset), static_cast<int>(origin)));
    }
    IData fdTell(IData fdi) VL_MT_SAFE_EXCLUDES(m_fdMutex) {
        const VerilatedLockGuard lock{m_fdMutex};
        const VerilatedFpList fdlist = fdToFpList(fdi);
-        if (VL_UNLIKELY(fdlist.size() != 1)) return 0;
+        if (VL_UNLIKELY(fdlist.size() != 1)) return ~0U;  // -1
        return static_cast<IData>(std::ftell(*fdlist.begin()));
    }
    void fdWrite(IData fdi, const std::string& output) VL_MT_SAFE_EXCLUDES(m_fdMutex) {
@@ -343,7 +341,7 @@ public:  // But only for verilated*.cpp
            if (VL_UNLIKELY(idx <= 2)) return;  // stdout/stdin/stderr
            if (VL_UNLIKELY(!m_fdps[idx])) return;  // Already free
            std::fclose(m_fdps[idx]);
-            m_fdps[idx] = (FILE*)0;
+            m_fdps[idx] = nullptr;
            m_fdFree.push_back(idx);
        } else {
            // MCD case
@@ -358,7 +356,7 @@ public:  // But only for verilated*.cpp
            }
        }
    }
-    inline FILE* fdToFp(IData fdi) VL_MT_SAFE_EXCLUDES(m_fdMutex) {
+    FILE* fdToFp(IData fdi) VL_MT_SAFE_EXCLUDES(m_fdMutex) {
        const VerilatedLockGuard lock{m_fdMutex};
        const VerilatedFpList fdlist = fdToFpList(fdi);
        if (VL_UNLIKELY(fdlist.size() != 1)) return nullptr;
@@ -394,7 +392,11 @@ protected:
    // METHODS - protected
    void commandArgsAddGuts(int argc, const char** argv);
    void commandArgVl(const std::string& arg);
-    bool commandArgVlValue(const std::string& arg, const std::string& prefix, std::string& valuer);
+    bool commandArgVlString(const std::string& arg, const std::string& prefix,
+                            std::string& valuer);
+    bool commandArgVlUint64(const std::string& arg, const std::string& prefix, uint64_t& valuer,
+                            uint64_t min = std::numeric_limits<uint64_t>::min(),
+                            uint64_t max = std::numeric_limits<uint64_t>::max());
    void commandArgDump() const VL_MT_SAFE_EXCLUDES(m_argMutex);
 };

@@ -459,13 +461,12 @@ public:
    // METHODS - debug
    static void versionDump() VL_MT_SAFE;

-public:
    // METHODS - user scope tracking
    // We implement this as a single large map instead of one map per scope.
    // There's often many more scopes than userdata's and thus having a ~48byte
    // per map overhead * N scopes would take much more space and cache thrashing.
    // As scopep's are pointers, this implicitly handles multiple Context's
-    static inline void userInsert(const void* scopep, void* userKey, void* userData) VL_MT_SAFE {
+    static void userInsert(const void* scopep, void* userKey, void* userData) VL_MT_SAFE {
        const VerilatedLockGuard lock{s().m_userMapMutex};
        const auto it = s().m_userMap.find(std::make_pair(scopep, userKey));
        if (it != s().m_userMap.end()) {
@@ -474,17 +475,18 @@ public:
            s().m_userMap.emplace(std::make_pair(scopep, userKey), userData);
        }
    }
-    static inline void* userFind(const void* scopep, void* userKey) VL_MT_SAFE {
+    static void* userFind(const void* scopep, void* userKey) VL_MT_SAFE {
        const VerilatedLockGuard lock{s().m_userMapMutex};
        const auto& it = vlstd::as_const(s().m_userMap).find(std::make_pair(scopep, userKey));
        if (VL_UNLIKELY(it == s().m_userMap.end())) return nullptr;
        return it->second;
    }

-public:  // But only for verilated.cpp
+    // METHODS - But only for verilated.cpp
+
    // Symbol table destruction cleans up the entries for each scope.
    static void userEraseScope(const VerilatedScope* scopep) VL_MT_SAFE {
-        // Slow ok - called once/scope on destruction, so we simply iterate.
+        // Slow ok - called once/scope on destruction, so we only iterate.
        const VerilatedLockGuard lock{s().m_userMapMutex};
        for (auto it = s().m_userMap.begin(); it != s().m_userMap.end();) {
            if (it->first.first == scopep) {
@@ -507,8 +509,7 @@ public:  // But only for verilated.cpp
        }
    }

-public:  // But only for verilated*.cpp
-    // METHODS - hierarchy
+    // METHODS - hierarchy - only for verilated*.cpp
    static void hierarchyAdd(const VerilatedScope* fromp, const VerilatedScope* top) VL_MT_SAFE {
        // Slow ok - called at construction for VPI accessible elements
        const VerilatedLockGuard lock{s().m_hierMapMutex};
@@ -529,8 +530,7 @@ public:  // But only for verilated*.cpp
        return &s().m_hierMap;
    }

-public:  // But only for verilated*.cpp
-    // METHODS - export names
+    // METHODS - export names - only for verilated*.cpp

    // Each function prototype is converted to a function number which we
    // then use to index a 2D table also indexed by scope number, because we
@@ -0,0 +1,225 @@
+// -*- mode: C++; c-file-style: "cc-mode" -*-
+//=============================================================================
+//
+// Code available from: https://verilator.org
+//
+// Copyright 2012-2022 by Wilson Snyder. This program is free software; you can
+// redistribute it and/or modify it under the terms of either the GNU
+// Lesser General Public License Version 3 or the Perl Artistic License
+// Version 2.0.
+// SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
+//
+//=============================================================================
+///
+/// \file
+/// \brief Verilated run-time profiling implementation code
+///
+//=============================================================================
+
+#include "verilatedos.h"
+
+#include "verilated_profiler.h"
+
+#if VL_THREADED
+#include "verilated_threads.h"
+#endif
+
+#include <fstream>
+#include <string>
+
+//=============================================================================
+// Globals
+
+// Internal note: Globals may multi-construct, see verilated.cpp top.
+
+VL_THREAD_LOCAL VlExecutionProfiler::ExecutionTrace VlExecutionProfiler::t_trace;
+
+constexpr const char* const VlExecutionRecord::s_ascii[];
+
+//=============================================================================
+// VlPgoProfiler implementation
+
+uint16_t VlExecutionRecord::getcpu() {
+#if defined(__linux)
+    return sched_getcpu();  // TODO: this is a system call. Not exactly cheap.
+#elif defined(__APPLE__) && !defined(__arm64__)
+    uint32_t info[4];
+    __cpuid_count(1, 0, info[0], info[1], info[2], info[3]);
+    // info[1] is EBX, bits 24-31 are APIC ID
+    if ((info[3] & (1 << 9)) == 0) {
+        return -1;  // no APIC on chip
+    } else {
+        return (unsigned)info[1] >> 24;
+    }
+#elif defined(_WIN32)
+    return GetCurrentProcessorNumber();
+#else
+    return 0;
+#endif
+}
+
+//=============================================================================
+// VlExecutionProfiler implementation
+
+template <size_t N>
+static size_t roundUptoMultipleOf(size_t value) {
+    static_assert((N & (N - 1)) == 0, "'N' must be a power of 2");
+    size_t mask = N - 1;
+    return (value + mask) & ~mask;
+}
+
+VlExecutionProfiler::VlExecutionProfiler(VerilatedContext& context)
+    : m_context{context} {
+    // Setup profiling on main thread
+    setupThread(0);
+}
+
+void VlExecutionProfiler::configure() {
+
+    if (VL_UNLIKELY(m_enabled)) {
+        --m_windowCount;
+        if (VL_UNLIKELY(m_windowCount == m_context.profExecWindow())) {
+            VL_DEBUG_IF(VL_DBG_MSGF("+ profile start collection\n"););
+            clear();  // Clear the profile after the cache warm-up cycles.
+            m_tickBegin = VL_CPU_TICK();
+        } else if (VL_UNLIKELY(m_windowCount == 0)) {
+            const uint64_t tickEnd = VL_CPU_TICK();
+            VL_DEBUG_IF(VL_DBG_MSGF("+ profile end\n"););
+            const std::string& fileName = m_context.profExecFilename();
+            dump(fileName.c_str(), tickEnd);
+            m_enabled = false;
+        }
+        return;
+    }
+
+    const uint64_t startReq = m_context.profExecStart() + 1;  // + 1, so we can start at time 0
+
+    if (VL_UNLIKELY(m_lastStartReq < startReq && VL_TIME_Q() >= m_context.profExecStart())) {
+        VL_DEBUG_IF(VL_DBG_MSGF("+ profile start warmup\n"););
+        VL_DEBUG_IF(assert(m_windowCount == 0););
+        m_enabled = true;
+        m_windowCount = m_context.profExecWindow() * 2;
+        m_lastStartReq = startReq;
+    }
+}
+
+VerilatedVirtualBase* VlExecutionProfiler::construct(VerilatedContext& context) {
+    VlExecutionProfiler* const selfp = new VlExecutionProfiler{context};
+#if VL_THREADED
+    if (VlThreadPool* const threadPoolp = static_cast<VlThreadPool*>(context.threadPoolp())) {
+        for (int i = 0; i < threadPoolp->numThreads(); ++i) {
+            // Data to pass to worker thread initialization
+            struct Data {
+                VlExecutionProfiler* const selfp;
+                const uint32_t threadId;
+            } data{selfp, static_cast<uint32_t>(i + 1)};
+
+            // Initialize worker thread
+            threadPoolp->workerp(i)->addTask(
+                [](void* userp, bool) {
+                    Data* const datap = static_cast<Data*>(userp);
+                    datap->selfp->setupThread(datap->threadId);
+                },
+                &data);
+
+            // Wait until initializationis complete
+            threadPoolp->workerp(i)->wait();
+        }
+    }
+#endif
+    return selfp;
+}
+
+void VlExecutionProfiler::setupThread(uint32_t threadId) {
+    // Reserve some space in the thread-local profiling buffer, in order to try to avoid malloc
+    // while profiling.
+    t_trace.reserve(RESERVED_TRACE_CAPACITY);
+    // Register thread-local buffer in list of all buffers
+    bool exists;
+    {
+        const VerilatedLockGuard lock{m_mutex};
+        exists = !m_traceps.emplace(threadId, &t_trace).second;
+    }
+    if (VL_UNLIKELY(exists)) {
+        VL_FATAL_MT(__FILE__, __LINE__, "", "multiple initialization of profiler on some thread");
+    }
+}
+
+void VlExecutionProfiler::clear() VL_MT_SAFE_EXCLUDES(m_mutex) {
+    const VerilatedLockGuard lock{m_mutex};
+    for (const auto& pair : m_traceps) {
+        ExecutionTrace* const tracep = pair.second;
+        const size_t reserve = roundUptoMultipleOf<RESERVED_TRACE_CAPACITY>(tracep->size());
+        tracep->clear();
+        tracep->reserve(reserve);
+    }
+}
+
+void VlExecutionProfiler::dump(const char* filenamep, uint64_t tickEnd)
+    VL_MT_SAFE_EXCLUDES(m_mutex) {
+    const VerilatedLockGuard lock{m_mutex};
+    VL_DEBUG_IF(VL_DBG_MSGF("+prof+exec writing to '%s'\n", filenamep););
+
+    FILE* const fp = std::fopen(filenamep, "w");
+    if (VL_UNLIKELY(!fp)) { VL_FATAL_MT(filenamep, 0, "", "+prof+exec+file file not writable"); }
+
+    // TODO Perhaps merge with verilated_coverage output format, so can
+    // have a common merging and reporting tool, etc.
+    fprintf(fp, "VLPROFVERSION 2.0 # Verilator execution profile version 2.0\n");
+    fprintf(fp, "VLPROF arg +verilator+prof+exec+start+%" PRIu64 "\n",
+            Verilated::threadContextp()->profExecStart());
+    fprintf(fp, "VLPROF arg +verilator+prof+exec+window+%u\n",
+            Verilated::threadContextp()->profExecWindow());
+    const unsigned threads = static_cast<unsigned>(m_traceps.size());
+    fprintf(fp, "VLPROF stat threads %u\n", threads);
+#ifdef VL_THREADED
+    fprintf(fp, "VLPROF stat yields %" PRIu64 "\n", VlMTaskVertex::yields());
+#endif
+
+    // Copy /proc/cpuinfo into this output so verilator_gantt can be run on
+    // a different machine
+    {
+        const std::unique_ptr<std::ifstream> ifp{new std::ifstream("/proc/cpuinfo")};
+        if (!ifp->fail()) {
+            std::string line;
+            while (std::getline(*ifp, line)) { fprintf(fp, "VLPROFPROC %s\n", line.c_str()); }
+        }
+    }
+
+    for (const auto& pair : m_traceps) {
+        const uint32_t threadId = pair.first;
+        ExecutionTrace* const tracep = pair.second;
+        fprintf(fp, "VLPROFTHREAD %" PRIu32 "\n", threadId);
+
+        for (const VlExecutionRecord& er : *tracep) {
+            const char* const name = VlExecutionRecord::s_ascii[static_cast<uint8_t>(er.m_type)];
+            const uint64_t time = er.m_tick - m_tickBegin;
+            fprintf(fp, "VLPROFEXEC %s %" PRIu64, name, time);
+
+            switch (er.m_type) {
+            case VlExecutionRecord::Type::EVAL_BEGIN:
+            case VlExecutionRecord::Type::EVAL_END:
+            case VlExecutionRecord::Type::EVAL_LOOP_BEGIN:
+            case VlExecutionRecord::Type::EVAL_LOOP_END:
+                // No payload
+                fprintf(fp, "\n");
+                break;
+            case VlExecutionRecord::Type::MTASK_BEGIN: {
+                const auto& payload = er.m_payload.mtaskBegin;
+                fprintf(fp, " id %u predictStart %u cpu %u\n", payload.m_id,
+                        payload.m_predictStart, payload.m_cpu);
+                break;
+            }
+            case VlExecutionRecord::Type::MTASK_END: {
+                const auto& payload = er.m_payload.mtaskEnd;
+                fprintf(fp, " id %u predictCost %u\n", payload.m_id, payload.m_predictCost);
+                break;
+            }
+            default: abort();  // LCOV_EXCL_LINE
+            }
+        }
+    }
+    fprintf(fp, "VLPROF stat ticks %" PRIu64 "\n", tickEnd - m_tickBegin);
+
+    std::fclose(fp);
+}
@@ -12,7 +12,7 @@
 //=============================================================================
 ///
 /// \file
-/// \brief Verilated general profiling header
+/// \brief Verilated run-time profiling header
 ///
 /// This file is not part of the Verilated public-facing API.
 /// It is only for internal use by Verilated library routines.
@@ -23,58 +23,206 @@
 #define VERILATOR_VERILATED_PROFILER_H_

 #include "verilatedos.h"
-#include "verilated.h"  // for VerilatedMutex and clang annotations

-#include <deque>
+#include "verilated.h"
+
+#include <array>
+#include <atomic>
+#include <cassert>
 #include <string>
+#include <type_traits>
+#include <vector>
+
+class VlExecutionProfiler;
+class VlThreadPool;
+
+//=============================================================================
+// Macros to simplify generated code
+
+#define VL_EXEC_TRACE_ADD_RECORD(vlSymsp) \
+    if (VL_UNLIKELY((vlSymsp)->__Vm_executionProfilerp->enabled())) \
+    (vlSymsp)->__Vm_executionProfilerp->addRecord()
+
+//=============================================================================
+// Return high-precision counter for profiling, or 0x0 if not available
+VL_ATTR_ALWINLINE QData VL_CPU_TICK() {
+    uint64_t val;
+    VL_GET_CPU_TICK(val);
+    return val;
+}
+
+//=============================================================================
+// Private class used by VlExecutionProfiler
+
+#define _VL_FOREACH_APPLY(macro, arg) macro(arg, #arg)
+
+// clang-format off
+#define FOREACH_VlExecutionRecord_TYPE(macro) \
+    _VL_FOREACH_APPLY(macro, EVAL_BEGIN) \
+    _VL_FOREACH_APPLY(macro, EVAL_END) \
+    _VL_FOREACH_APPLY(macro, EVAL_LOOP_BEGIN) \
+    _VL_FOREACH_APPLY(macro, EVAL_LOOP_END) \
+    _VL_FOREACH_APPLY(macro, MTASK_BEGIN) \
+    _VL_FOREACH_APPLY(macro, MTASK_END)
+// clang-format on
+
+class VlExecutionRecord final {
+    friend class VlExecutionProfiler;
+
+    // TYPES
+    enum class Type : uint8_t {
+#define VL_FOREACH_MACRO(id, name) id,
+        FOREACH_VlExecutionRecord_TYPE(VL_FOREACH_MACRO)
+#undef VL_FOREACH_MACRO
+    };
+
+    static constexpr const char* const s_ascii[] = {
+#define VL_FOREACH_MACRO(id, name) name,
+        FOREACH_VlExecutionRecord_TYPE(VL_FOREACH_MACRO)
+#undef VL_FOREACH_MACRO
+    };
+
+    union Payload {
+        struct {
+            uint32_t m_id;  // MTask id
+            uint32_t m_predictStart;  // Time scheduler predicted would start
+            uint32_t m_cpu;  // Executing CPU id
+        } mtaskBegin;
+        struct {
+            uint32_t m_id;  // MTask id
+            uint32_t m_predictCost;  // How long scheduler predicted would take
+        } mtaskEnd;
+    };
+
+    // STATE
+    // Layout below allows efficient packing.
+    const uint64_t m_tick = VL_CPU_TICK();  // Tick at construction
+    Payload m_payload;  // The record payload
+    Type m_type;  // The record type
+    static_assert(alignof(uint64_t) >= alignof(Payload), "Padding not allowed");
+    static_assert(alignof(Payload) >= alignof(Type), "Padding not allowed");
+
+    static uint16_t getcpu();  // Return currently executing CPU id

-// Profile record, private class used only by this header
-class VerilatedProfilerRec final {
-    const std::string m_name;  // Hashed name of mtask/etc
-    const size_t m_counterNumber = 0;  // Which counter has data
 public:
+    // CONSTRUCTOR
+    VlExecutionRecord() = default;
+
    // METHODS
-    VerilatedProfilerRec(size_t counterNumber, const std::string& name)
-        : m_name{name}
-        , m_counterNumber{counterNumber} {}
-    VerilatedProfilerRec() = default;
-    size_t counterNumber() const { return m_counterNumber; }
-    std::string name() const { return m_name; }
+    void evalBegin() { m_type = Type::EVAL_BEGIN; }
+    void evalEnd() { m_type = Type::EVAL_END; }
+    void evalLoopBegin() { m_type = Type::EVAL_LOOP_BEGIN; }
+    void evalLoopEnd() { m_type = Type::EVAL_LOOP_END; }
+    void mtaskBegin(uint32_t id, uint32_t predictStart) {
+        m_payload.mtaskBegin.m_id = id;
+        m_payload.mtaskBegin.m_predictStart = predictStart;
+        m_payload.mtaskBegin.m_cpu = getcpu();
+        m_type = Type::MTASK_BEGIN;
+    }
+    void mtaskEnd(uint32_t id, uint32_t predictCost) {
+        m_payload.mtaskEnd.m_id = id;
+        m_payload.mtaskEnd.m_predictCost = predictCost;
+        m_type = Type::MTASK_END;
+    }
 };

-// Create some number of bucketed profilers
-template <std::size_t T_Entries> class VerilatedProfiler final {
-    // Counters are stored packed, all together, versus in VerilatedProfilerRec to
-    // reduce cache effects
-    std::array<vluint64_t, T_Entries> m_counters{};  // Time spent on this record
-    std::deque<VerilatedProfilerRec> m_records;  // Record information
+static_assert(std::is_trivially_destructible<VlExecutionRecord>::value,
+              "VlExecutionRecord should be trivially destructible for fast buffer clearing");
+
+//=============================================================================
+// VlExecutionProfiler is for collecting profiling data about model execution
+
+class VlExecutionProfiler final : public VerilatedVirtualBase {
+    // CONSTANTS
+
+    // In order to try to avoid dynamic memory allocations during the actual profiling phase,
+    // trace buffers are pre-allocated to be able to hold [a multiple] of this many records.
+    static constexpr size_t RESERVED_TRACE_CAPACITY = 4096;
+
+    // TYPES
+
+    // Execution traces are recorded into thread local vectors. We can append records of profiling
+    // events to this vector with very low overhead, and then dump them out later. This prevents
+    // the overhead of printf/malloc/IO from corrupting the profiling data. It's super cheap to
+    // append a VlProfileRec struct on the end of a pre-allocated vector; this is the only cost we
+    // pay in real-time during a profiling cycle. Internal note: Globals may multi-construct, see
+    // verilated.cpp top.
+    using ExecutionTrace = std::vector<VlExecutionRecord>;
+
+    // STATE
+    VerilatedContext& m_context;  // The context this profiler is under
+    static VL_THREAD_LOCAL ExecutionTrace t_trace;  // thread-local trace buffers
+    mutable VerilatedMutex m_mutex;
+    // Map from thread id to &t_trace of given thread
+    std::map<uint32_t, ExecutionTrace*> m_traceps VL_GUARDED_BY(m_mutex);
+
+    bool m_enabled = false;  // Is profiling currently enabled
+
+    uint64_t m_tickBegin = 0;  // Sample time (rdtsc() on x86) at beginning of collection
+    uint64_t m_lastStartReq = 0;  // Last requested profiling start (in simulation time)
+    uint32_t m_windowCount = 0;  // Track our position in the cache warmup and profile window
+
+public:
+    // CONSTRUCTOR
+    explicit VlExecutionProfiler(VerilatedContext& context);
+    ~VlExecutionProfiler() override = default;
+
+    // METHODS
+
+    // Is profiling enabled
+    bool enabled() const { return m_enabled; }
+    // Append a trace record to the trace buffer of the current thread
+    static VlExecutionRecord& addRecord() {
+        t_trace.emplace_back();
+        return t_trace.back();
+    }
+    // Configure profiler (called in beginning of 'eval')
+    void configure();
+    // Setup profiling on a particular thread;
+    void setupThread(uint32_t threadId);
+    // Clear all profiling data
+    void clear() VL_MT_SAFE_EXCLUDES(m_mutex);
+    // Write profiling data into file
+    void dump(const char* filenamep, uint64_t tickEnd) VL_MT_SAFE_EXCLUDES(m_mutex);
+
+    // Passed to VerilatedContext to create the VlExecutionProfiler profiler instance
+    static VerilatedVirtualBase* construct(VerilatedContext& context);
+};
+
+//=============================================================================
+// VlPgoProfiler is for collecting profiling data for PGO
+
+template <std::size_t T_Entries>
+class VlPgoProfiler final {
+    // TYPES
+    struct Record final {
+        const std::string m_name;  // Hashed name of mtask/etc
+        const size_t m_counterNumber = 0;  // Which counter has data
+    };
+
+    // Counters are stored packed, all together to reduce cache effects
+    std::array<uint64_t, T_Entries> m_counters;  // Time spent on this record
+    std::vector<Record> m_records;  // Record information

 public:
    // METHODS
-    VerilatedProfiler() = default;
-    ~VerilatedProfiler() = default;
+    VlPgoProfiler() = default;
+    ~VlPgoProfiler() = default;
    void write(const char* modelp, const std::string& filename) VL_MT_SAFE;
    void addCounter(size_t counter, const std::string& name) {
        VL_DEBUG_IF(assert(counter < T_Entries););
-        m_records.emplace_back(VerilatedProfilerRec{counter, name});
+        m_records.emplace_back(Record{name, counter});
    }
    void startCounter(size_t counter) {
-        vluint64_t val;
-        VL_RDTSC(val);
-        // -= so when we add end time in stopCounter, we already subtracted
-        // out, without needing to hold another temporary
-        m_counters[counter] -= val;
-    }
-    void stopCounter(size_t counter) {
-        vluint64_t val;
-        VL_RDTSC(val);
-        m_counters[counter] += val;
+        // -= so when we add end time in stopCounter, the net effect is adding the difference,
+        // without needing to hold onto a temporary
+        m_counters[counter] -= VL_CPU_TICK();
    }
+    void stopCounter(size_t counter) { m_counters[counter] += VL_CPU_TICK(); }
 };

 template <std::size_t T_Entries>
-void VerilatedProfiler<T_Entries>::write(const char* modelp,
-                                         const std::string& filename) VL_MT_SAFE {
+void VlPgoProfiler<T_Entries>::write(const char* modelp, const std::string& filename) VL_MT_SAFE {
    static VerilatedMutex s_mutex;
    const VerilatedLockGuard lock{s_mutex};

@@ -82,20 +230,15 @@ void VerilatedProfiler<T_Entries>::write(const char* modelp,
    // So when we have multiple models in an executable, possibly even
    // running on different threads, each will have a different symtab so
    // each will collect is own data correctly.  However when each is
-    // destroid we need to get all the data, not keep overwriting and only
+    // destroyed we need to get all the data, not keep overwriting and only
    // get the last model's data.
    static bool s_firstCall = true;

    VL_DEBUG_IF(VL_DBG_MSGF("+prof+vlt+file writing to '%s'\n", filename.c_str()););

-    FILE* fp = nullptr;
-    if (!s_firstCall) fp = std::fopen(filename.c_str(), "a");
-    if (VL_UNLIKELY(!fp))
-        fp = std::fopen(filename.c_str(), "w");  // firstCall, or doesn't exist yet
+    FILE* const fp = std::fopen(filename.c_str(), s_firstCall ? "w" : "a");
    if (VL_UNLIKELY(!fp)) {
        VL_FATAL_MT(filename.c_str(), 0, "", "+prof+vlt+file file not writable");
-        // cppcheck-suppress resourceLeak   // bug, doesn't realize fp is nullptr
-        return;  // LCOV_EXCL_LINE
    }
    s_firstCall = false;

@@ -104,10 +247,9 @@ void VerilatedProfiler<T_Entries>::write(const char* modelp,
    fprintf(fp, "// Verilated model profile-guided optimization data dump file\n");
    fprintf(fp, "`verilator_config\n");

-    for (const auto& it : m_records) {
-        const std::string& name = it.name();
+    for (const Record& rec : m_records) {
        fprintf(fp, "profile_data -model \"%s\" -mtask \"%s\" -cost 64'd%" PRIu64 "\n", modelp,
-                name.c_str(), m_counters[it.counterNumber()]);
+                rec.m_name.c_str(), m_counters[rec.m_counterNumber]);
    }

    std::fclose(fp);
@@ -24,8 +24,10 @@
 #define VERILATOR_VERILATED_SAVE_CPP_

 #include "verilatedos.h"
-#include "verilated.h"
+
 #include "verilated_save.h"
+
+#include "verilated.h"
 #include "verilated_imp.h"

 #include <cerrno>
@@ -38,13 +40,13 @@
 # include <unistd.h>
 #endif

-#ifndef O_LARGEFILE  // For example on WIN32
+#ifndef O_LARGEFILE  // WIN32 headers omit this
 # define O_LARGEFILE 0
 #endif
-#ifndef O_NONBLOCK
+#ifndef O_NONBLOCK  // WIN32 headers omit this
 # define O_NONBLOCK 0
 #endif
-#ifndef O_CLOEXEC
+#ifndef O_CLOEXEC  // WIN32 headers omit this
 # define O_CLOEXEC 0
 #endif
 // clang-format on
@@ -63,8 +65,8 @@ static const char* const VLTSAVE_TRAILER_STR = "vltsaved";
 bool VerilatedDeserialize::readDiffers(const void* __restrict datap,
                                       size_t size) VL_MT_UNSAFE_ONE {
    bufferCheck();
-    const vluint8_t* __restrict dp = static_cast<const vluint8_t* __restrict>(datap);
-    vluint8_t miss = 0;
+    const uint8_t* __restrict dp = static_cast<const uint8_t* __restrict>(datap);
+    uint8_t miss = 0;
    while (size--) miss |= (*dp++ ^ *m_cp++);
    return (miss != 0);
 }
@@ -192,7 +194,7 @@ void VerilatedRestore::close() VL_MT_UNSAFE_ONE {
 void VerilatedSave::flush() VL_MT_UNSAFE_ONE {
    m_assertOne.check();
    if (VL_UNLIKELY(!isOpen())) return;
-    const vluint8_t* wp = m_bufp;
+    const uint8_t* wp = m_bufp;
    while (true) {
        const ssize_t remaining = (m_cp - wp);
        if (remaining == 0) break;
@@ -219,8 +221,8 @@ void VerilatedRestore::fill() VL_MT_UNSAFE_ONE {
    m_assertOne.check();
    if (VL_UNLIKELY(!isOpen())) return;
    // Move remaining characters down to start of buffer.  (No memcpy, overlaps allowed)
-    vluint8_t* rp = m_bufp;
-    for (vluint8_t* sp = m_cp; sp < m_endp; *rp++ = *sp++) {}  // Overlaps
+    uint8_t* rp = m_bufp;
+    for (uint8_t* sp = m_cp; sp < m_endp; *rp++ = *sp++) {}  // Overlaps
    m_endp = m_bufp + (m_endp - m_cp);
    m_cp = m_bufp;  // Reset buffer
    // Read into buffer starting at m_endp
@@ -23,6 +23,7 @@
 #define VERILATOR_VERILATED_SAVE_C_H_

 #include "verilatedos.h"
+
 #include "verilated.h"

 #include <string>
@@ -40,8 +41,8 @@ class VerilatedSerialize VL_NOT_FINAL {
 protected:
    // MEMBERS
    // For speed, keep m_cp as the first member of this structure
-    vluint8_t* m_cp;  // Current pointer into m_bufp buffer
-    vluint8_t* m_bufp;  // Output buffer
+    uint8_t* m_cp;  // Current pointer into m_bufp buffer
+    uint8_t* m_bufp;  // Output buffer
    bool m_isOpen = false;  // True indicates open file/stream
    std::string m_filename;  // Filename, for error messages
    VerilatedAssertOneThread m_assertOne;  // Assert only called from single thread
@@ -58,7 +59,7 @@ protected:
 public:
    /// Construct
    VerilatedSerialize() {
-        m_bufp = new vluint8_t[bufferSize()];
+        m_bufp = new uint8_t[bufferSize()];
        m_cp = m_bufp;
    }
    /// Flish, close, and destruct
@@ -77,12 +78,12 @@ public:
    virtual void flush() VL_MT_UNSAFE_ONE {}
    /// Write data to stream
    VerilatedSerialize& write(const void* __restrict datap, size_t size) VL_MT_UNSAFE_ONE {
-        const vluint8_t* __restrict dp = (const vluint8_t* __restrict)datap;
+        const uint8_t* __restrict dp = static_cast<const uint8_t* __restrict>(datap);
        while (size) {
            bufferCheck();
            size_t blk = size;
            if (blk > bufferInsertSize()) blk = bufferInsertSize();
-            const vluint8_t* __restrict maxp = dp + blk;
+            const uint8_t* __restrict maxp = dp + blk;
            for (; dp < maxp; *m_cp++ = *dp++) {}
            size -= blk;
        }
@@ -111,9 +112,9 @@ class VerilatedDeserialize VL_NOT_FINAL {
 protected:
    // MEMBERS
    // For speed, keep m_cp as the first member of this structure
-    vluint8_t* m_cp;  // Current pointer into m_bufp buffer
-    vluint8_t* m_bufp;  // Output buffer
-    vluint8_t* m_endp = nullptr;  // Last valid byte in m_bufp buffer
+    uint8_t* m_cp;  // Current pointer into m_bufp buffer
+    uint8_t* m_bufp;  // Output buffer
+    uint8_t* m_endp = nullptr;  // Last valid byte in m_bufp buffer
    bool m_isOpen = false;  // True indicates open file/stream
    std::string m_filename;  // Filename, for error messages
    VerilatedAssertOneThread m_assertOne;  // Assert only called from single thread
@@ -131,7 +132,7 @@ protected:
 public:
    /// Construct
    VerilatedDeserialize() {
-        m_bufp = new vluint8_t[bufferSize()];
+        m_bufp = new uint8_t[bufferSize()];
        m_cp = m_bufp;
    }
    /// Destruct
@@ -150,12 +151,12 @@ public:
    virtual void flush() VL_MT_UNSAFE_ONE {}
    /// Read data from stream
    VerilatedDeserialize& read(void* __restrict datap, size_t size) VL_MT_UNSAFE_ONE {
-        vluint8_t* __restrict dp = static_cast<vluint8_t* __restrict>(datap);
+        uint8_t* __restrict dp = static_cast<uint8_t* __restrict>(datap);
        while (size) {
            bufferCheck();
            size_t blk = size;
            if (blk > bufferInsertSize()) blk = bufferInsertSize();
-            const vluint8_t* __restrict maxp = dp + blk;
+            const uint8_t* __restrict maxp = dp + blk;
            for (; dp < maxp; *dp++ = *m_cp++) {}
            size -= blk;
        }
@@ -165,7 +166,7 @@ public:
    // Internal use:
    // Read a datum and compare with expected value
    VerilatedDeserialize& readAssert(const void* __restrict datap, size_t size) VL_MT_UNSAFE_ONE;
-    VerilatedDeserialize& readAssert(vluint64_t data) VL_MT_UNSAFE_ONE {
+    VerilatedDeserialize& readAssert(uint64_t data) VL_MT_UNSAFE_ONE {
        return readAssert(&data, sizeof(data));
    }

@@ -194,16 +195,16 @@ public:
    /// Construct new object
    VerilatedSave() = default;
    /// Flush, close and destruct
-    virtual ~VerilatedSave() override { close(); }
+    ~VerilatedSave() override { close(); }
    // METHODS
    /// Open the file; call isOpen() to see if errors
    void open(const char* filenamep) VL_MT_UNSAFE_ONE;
    /// Open the file; call isOpen() to see if errors
    void open(const std::string& filename) VL_MT_UNSAFE_ONE { open(filename.c_str()); }
    /// Flush and close the file
-    virtual void close() override VL_MT_UNSAFE_ONE;
+    void close() override VL_MT_UNSAFE_ONE;
    /// Flush data to file
-    virtual void flush() override VL_MT_UNSAFE_ONE;
+    void flush() override VL_MT_UNSAFE_ONE;
 };

 //=============================================================================
@@ -221,7 +222,7 @@ public:
    /// Construct new object
    VerilatedRestore() = default;
    /// Flush, close and destruct
-    virtual ~VerilatedRestore() override { close(); }
+    ~VerilatedRestore() override { close(); }

    // METHODS
    /// Open the file; call isOpen() to see if errors
@@ -229,35 +230,35 @@ public:
    /// Open the file; call isOpen() to see if errors
    void open(const std::string& filename) VL_MT_UNSAFE_ONE { open(filename.c_str()); }
    /// Close the file
-    virtual void close() override VL_MT_UNSAFE_ONE;
-    virtual void flush() override VL_MT_UNSAFE_ONE {}
-    virtual void fill() override VL_MT_UNSAFE_ONE;
+    void close() override VL_MT_UNSAFE_ONE;
+    void flush() override VL_MT_UNSAFE_ONE {}
+    void fill() override VL_MT_UNSAFE_ONE;
 };

 //=============================================================================

-inline VerilatedSerialize& operator<<(VerilatedSerialize& os, const vluint64_t& rhs) {
+inline VerilatedSerialize& operator<<(VerilatedSerialize& os, const uint64_t& rhs) {
    return os.write(&rhs, sizeof(rhs));
 }
-inline VerilatedDeserialize& operator>>(VerilatedDeserialize& os, vluint64_t& rhs) {
+inline VerilatedDeserialize& operator>>(VerilatedDeserialize& os, uint64_t& rhs) {
    return os.read(&rhs, sizeof(rhs));
 }
-inline VerilatedSerialize& operator<<(VerilatedSerialize& os, const vluint32_t& rhs) {
+inline VerilatedSerialize& operator<<(VerilatedSerialize& os, const uint32_t& rhs) {
    return os.write(&rhs, sizeof(rhs));
 }
-inline VerilatedDeserialize& operator>>(VerilatedDeserialize& os, vluint32_t& rhs) {
+inline VerilatedDeserialize& operator>>(VerilatedDeserialize& os, uint32_t& rhs) {
    return os.read(&rhs, sizeof(rhs));
 }
-inline VerilatedSerialize& operator<<(VerilatedSerialize& os, const vluint16_t& rhs) {
+inline VerilatedSerialize& operator<<(VerilatedSerialize& os, const uint16_t& rhs) {
    return os.write(&rhs, sizeof(rhs));
 }
-inline VerilatedDeserialize& operator>>(VerilatedDeserialize& os, vluint16_t& rhs) {
+inline VerilatedDeserialize& operator>>(VerilatedDeserialize& os, uint16_t& rhs) {
    return os.read(&rhs, sizeof(rhs));
 }
-inline VerilatedSerialize& operator<<(VerilatedSerialize& os, const vluint8_t& rhs) {
+inline VerilatedSerialize& operator<<(VerilatedSerialize& os, const uint8_t& rhs) {
    return os.write(&rhs, sizeof(rhs));
 }
-inline VerilatedDeserialize& operator>>(VerilatedDeserialize& os, vluint8_t& rhs) {
+inline VerilatedDeserialize& operator>>(VerilatedDeserialize& os, uint8_t& rhs) {
    return os.read(&rhs, sizeof(rhs));
 }
 inline VerilatedSerialize& operator<<(VerilatedSerialize& os, const bool& rhs) {
@@ -279,15 +280,16 @@ inline VerilatedDeserialize& operator>>(VerilatedDeserialize& os, float& rhs) {
    return os.read(&rhs, sizeof(rhs));
 }
 inline VerilatedSerialize& operator<<(VerilatedSerialize& os, const std::string& rhs) {
-    const vluint32_t len = rhs.length();
+    const uint32_t len = rhs.length();
    os << len;
    return os.write(rhs.data(), len);
 }
 inline VerilatedDeserialize& operator>>(VerilatedDeserialize& os, std::string& rhs) {
-    vluint32_t len = 0;
+    uint32_t len = 0;
    os >> len;
    rhs.resize(len);
-    return os.read((void*)rhs.data(), len);
+    // C cast is required below
+    return os.read((void*)(rhs.data()), len);
 }
 VerilatedSerialize& operator<<(VerilatedSerialize& os, VerilatedContext* rhsp);
 VerilatedDeserialize& operator>>(VerilatedDeserialize& os, VerilatedContext* rhsp);
@@ -295,7 +297,7 @@ VerilatedDeserialize& operator>>(VerilatedDeserialize& os, VerilatedContext* rhs
 template <class T_Key, class T_Value>
 VerilatedSerialize& operator<<(VerilatedSerialize& os, VlAssocArray<T_Key, T_Value>& rhs) {
    os << rhs.atDefault();
-    const vluint32_t len = rhs.size();
+    const uint32_t len = rhs.size();
    os << len;
    for (const auto& i : rhs) {
        const T_Key index = i.first;  // Copy to get around const_iterator
@@ -307,10 +309,10 @@ VerilatedSerialize& operator<<(VerilatedSerialize& os, VlAssocArray<T_Key, T_Val
 template <class T_Key, class T_Value>
 VerilatedDeserialize& operator>>(VerilatedDeserialize& os, VlAssocArray<T_Key, T_Value>& rhs) {
    os >> rhs.atDefault();
-    vluint32_t len = 0;
+    uint32_t len = 0;
    os >> len;
    rhs.clear();
-    for (vluint32_t i = 0; i < len; ++i) {
+    for (uint32_t i = 0; i < len; ++i) {
        T_Key index;
        T_Value value;
        os >> index;
@@ -39,10 +39,10 @@
 // This class is thread safe (though most of SystemC is not).
 class VlScBvExposer final : public sc_bv_base {
 public:
-    static const vluint32_t* sp_datap(const sc_bv_base& base) VL_MT_SAFE {
+    static const uint32_t* sp_datap(const sc_bv_base& base) VL_MT_SAFE {
        return static_cast<const VlScBvExposer*>(&base)->sp_datatp();
    }
-    const vluint32_t* sp_datatp() const { return reinterpret_cast<vluint32_t*>(m_data); }
+    const uint32_t* sp_datatp() const { return reinterpret_cast<uint32_t*>(m_data); }
    // Above reads this protected element in sc_bv_base:
    //   sc_digit* m_data; // data array
 };
@@ -69,9 +69,9 @@ public:

 class VerilatedVarProps VL_NOT_FINAL {
    // TYPES
-    static constexpr vluint32_t MAGIC = 0xddc4f829UL;
+    static constexpr uint32_t MAGIC = 0xddc4f829UL;
    // MEMBERS
-    const vluint32_t m_magic;  // Magic number
+    const uint32_t m_magic;  // Magic number
    const VerilatedVarType m_vltype;  // Data type
    const VerilatedVarFlags m_vlflags;  // Direction
    const int m_pdims;  // Packed dimensions, 0 = none
@@ -134,7 +134,6 @@ public:
        initUnpacked(ulims);
    }

-public:
    ~VerilatedVarProps() = default;
    // METHODS
    bool magicOk() const { return m_magic == MAGIC; }
@@ -142,7 +141,7 @@ public:
    VerilatedVarFlags vldir() const {
        return static_cast<VerilatedVarFlags>(static_cast<int>(m_vlflags) & VLVF_MASK_DIR);
    }
-    vluint32_t entSize() const;
+    uint32_t entSize() const;
    bool isPublicRW() const { return ((m_vlflags & VLVF_PUB_RW) != 0); }
    // DPI compatible C standard layout
    bool isDpiCLayout() const { return ((m_vlflags & VLVF_DPI_CLAY) != 0); }
@@ -30,6 +30,7 @@
 #define VERILATOR_VERILATED_SYMS_H_

 #include "verilatedos.h"
+
 #include "verilated.h"
 #include "verilated_sym_props.h"

@@ -22,10 +22,10 @@
 //=============================================================================

 #include "verilatedos.h"
+
 #include "verilated_threads.h"

 #include <cstdio>
-#include <fstream>
 #include <memory>
 #include <string>

@@ -34,14 +34,12 @@

 // Internal note: Globals may multi-construct, see verilated.cpp top.

-std::atomic<vluint64_t> VlMTaskVertex::s_yields;
-
-VL_THREAD_LOCAL VlThreadPool::ProfileTrace* VlThreadPool::t_profilep = nullptr;
+std::atomic<uint64_t> VlMTaskVertex::s_yields;

 //=============================================================================
 // VlMTaskVertex

-VlMTaskVertex::VlMTaskVertex(vluint32_t upstreamDepCount)
+VlMTaskVertex::VlMTaskVertex(uint32_t upstreamDepCount)
    : m_upstreamDepsDone{0}
    , m_upstreamDepCount{upstreamDepCount} {
    assert(atomic_is_lock_free(&m_upstreamDepsDone));
@@ -50,175 +48,62 @@ VlMTaskVertex::VlMTaskVertex(vluint32_t upstreamDepCount)
 //=============================================================================
 // VlWorkerThread

-VlWorkerThread::VlWorkerThread(VlThreadPool* poolp, VerilatedContext* contextp, bool profiling)
+VlWorkerThread::VlWorkerThread(VerilatedContext* contextp)
    : m_ready_size{0}
-    , m_poolp{poolp}
-    , m_profiling{profiling}  // Must init this last -- after setting up fields that it might read:
-    , m_exiting{false}
-    , m_cthread{startWorker, this}
-    , m_contextp{contextp} {}
+    , m_cthread{startWorker, this, contextp} {}

 VlWorkerThread::~VlWorkerThread() {
-    m_exiting.store(true, std::memory_order_release);
-    wakeUp();
+    shutdown();
    // The thread should exit; join it.
    m_cthread.join();
 }

-void VlWorkerThread::workerLoop() {
-    if (VL_UNLIKELY(m_profiling)) m_poolp->setupProfilingClientThread();
-
-    ExecRec work;
-    work.m_fnp = nullptr;
-
-    while (true) {
-        if (VL_LIKELY(!work.m_fnp)) dequeWork(&work);
-
-        // Do this here, not above, to avoid a race with the destructor.
-        if (VL_UNLIKELY(m_exiting.load(std::memory_order_acquire))) break;
-
-        if (VL_LIKELY(work.m_fnp)) {
-            work.m_fnp(work.m_selfp, work.m_evenCycle);
-            work.m_fnp = nullptr;
-        }
-    }
-
-    if (VL_UNLIKELY(m_profiling)) m_poolp->tearDownProfilingClientThread();
+static void shutdownTask(void*, bool) {
+    // Deliberately empty, we use the address of this function as a magic number
 }

-void VlWorkerThread::startWorker(VlWorkerThread* workerp) {
-    Verilated::threadContextp(workerp->m_contextp);
+void VlWorkerThread::shutdown() { addTask(shutdownTask, nullptr); }
+
+void VlWorkerThread::wait() {
+    // Enqueue a task that sets this flag. Execution is in-order so this ensures completion.
+    std::atomic<bool> flag{false};
+    addTask([](void* flagp, bool) { static_cast<std::atomic<bool>*>(flagp)->store(true); }, &flag);
+    // Spin wait
+    for (unsigned i = 0; i < VL_LOCK_SPINS; ++i) {
+        if (flag.load()) return;
+        VL_CPU_RELAX();
+    }
+    // Yield wait
+    while (!flag.load()) std::this_thread::yield();
+}
+
+void VlWorkerThread::workerLoop() {
+    ExecRec work;
+
+    // Wait for the first task without spinning, in case the thread is never actually used.
+    dequeWork</* SpinWait: */ false>(&work);
+
+    while (true) {
+        if (VL_UNLIKELY(work.m_fnp == shutdownTask)) break;
+        work.m_fnp(work.m_selfp, work.m_evenCycle);
+        // Wait for next task with spinning.
+        dequeWork</* SpinWait: */ true>(&work);
+    }
+}
+
+void VlWorkerThread::startWorker(VlWorkerThread* workerp, VerilatedContext* contextp) {
+    Verilated::threadContextp(contextp);
    workerp->workerLoop();
 }

 //=============================================================================
 // VlThreadPool

-VlThreadPool::VlThreadPool(VerilatedContext* contextp, int nThreads, bool profiling)
-    : m_profiling{profiling} {
-    // --threads N passes nThreads=N-1, as the "main" threads counts as 1
-    const unsigned cpus = std::thread::hardware_concurrency();
-    if (cpus < nThreads + 1) {
-        static int warnedOnce = 0;
-        if (!warnedOnce++) {
-            VL_PRINTF_MT("%%Warning: System has %u CPUs but model Verilated with"
-                         " --threads %d; may run slow.\n",
-                         cpus, nThreads + 1);
-        }
-    }
-    // Create'em
-    for (int i = 0; i < nThreads; ++i) {
-        m_workers.push_back(new VlWorkerThread{this, contextp, profiling});
-    }
-    // Set up a profile buffer for the current thread too -- on the
-    // assumption that it's the same thread that calls eval and may be
-    // donated to run mtasks during the eval.
-    if (VL_UNLIKELY(m_profiling)) setupProfilingClientThread();
+VlThreadPool::VlThreadPool(VerilatedContext* contextp, unsigned nThreads) {
+    for (unsigned i = 0; i < nThreads; ++i) m_workers.push_back(new VlWorkerThread{contextp});
 }

 VlThreadPool::~VlThreadPool() {
    // Each ~WorkerThread will wait for its thread to exit.
    for (auto& i : m_workers) delete i;
-    if (VL_UNLIKELY(m_profiling)) tearDownProfilingClientThread();
-}
-
-void VlThreadPool::tearDownProfilingClientThread() {
-    assert(t_profilep);
-    delete t_profilep;
-    t_profilep = nullptr;
-}
-
-void VlThreadPool::setupProfilingClientThread() VL_MT_SAFE_EXCLUDES(m_mutex) {
-    assert(!t_profilep);
-    t_profilep = new ProfileTrace;
-    // Reserve some space in the thread-local profiling buffer;
-    // try not to malloc while collecting profiling.
-    t_profilep->reserve(4096);
-    {
-        const VerilatedLockGuard lock{m_mutex};
-        m_allProfiles.insert(t_profilep);
-    }
-}
-
-void VlThreadPool::profileAppendAll(const VlProfileRec& rec) VL_MT_SAFE_EXCLUDES(m_mutex) {
-    const VerilatedLockGuard lock{m_mutex};
-    for (const auto& profilep : m_allProfiles) {
-        // Every thread's profile trace gets a copy of rec.
-        profilep->emplace_back(rec);
-    }
-}
-
-void VlThreadPool::profileDump(const char* filenamep, vluint64_t tickStart, vluint64_t tickEnd)
-    VL_MT_SAFE_EXCLUDES(m_mutex) {
-    const VerilatedLockGuard lock{m_mutex};
-    VL_DEBUG_IF(VL_DBG_MSGF("+prof+threads writing to '%s'\n", filenamep););
-
-    FILE* const fp = std::fopen(filenamep, "w");
-    if (VL_UNLIKELY(!fp)) {
-        VL_FATAL_MT(filenamep, 0, "", "+prof+threads+file file not writable");
-        // cppcheck-suppress resourceLeak   // bug, doesn't realize fp is nullptr
-        return;  // LCOV_EXCL_LINE
-    }
-
-    // TODO Perhaps merge with verilated_coverage output format, so can
-    // have a common merging and reporting tool, etc.
-    fprintf(fp, "VLPROFTHREAD 1.1 # Verilator thread profile dump version 1.1\n");
-    fprintf(fp, "VLPROF arg --threads %" PRIu64 "\n", vluint64_t(m_workers.size() + 1));
-    fprintf(fp, "VLPROF arg +verilator+prof+threads+start+%" PRIu64 "\n",
-            Verilated::threadContextp()->profThreadsStart());
-    fprintf(fp, "VLPROF arg +verilator+prof+threads+window+%u\n",
-            Verilated::threadContextp()->profThreadsWindow());
-    fprintf(fp, "VLPROF stat yields %" PRIu64 "\n", VlMTaskVertex::yields());
-
-    // Copy /proc/cpuinfo into this output so verilator_gantt can be run on
-    // a different machine
-    {
-        const std::unique_ptr<std::ifstream> ifp{new std::ifstream("/proc/cpuinfo")};
-        if (!ifp->fail()) {
-            std::string line;
-            while (std::getline(*ifp, line)) { fprintf(fp, "VLPROFPROC %s\n", line.c_str()); }
-        }
-    }
-
-    vluint32_t thread_id = 0;
-    for (const auto& pi : m_allProfiles) {
-        ++thread_id;
-
-        bool printing = false;  // False while in warmup phase
-        for (const auto& ei : *pi) {
-            switch (ei.m_type) {
-            case VlProfileRec::TYPE_BARRIER:  //
-                printing = true;
-                break;
-            case VlProfileRec::TYPE_EVAL:
-                if (!printing) break;
-                fprintf(fp,
-                        "VLPROF eval start %" PRIu64 " elapsed %" PRIu64 " cpu %u on thread %u\n",
-                        ei.m_startTime - tickStart, (ei.m_endTime - ei.m_startTime), ei.m_cpu,
-                        thread_id);
-                break;
-            case VlProfileRec::TYPE_EVAL_LOOP:
-                if (!printing) break;
-                fprintf(fp,
-                        "VLPROF eval_loop start %" PRIu64 " elapsed %" PRIu64
-                        " cpu %u on thread %u\n",
-                        ei.m_startTime - tickStart, (ei.m_endTime - ei.m_startTime), ei.m_cpu,
-                        thread_id);
-                break;
-            case VlProfileRec::TYPE_MTASK_RUN:
-                if (!printing) break;
-                fprintf(fp,
-                        "VLPROF mtask %d"
-                        " start %" PRIu64 " elapsed %" PRIu64
-                        " predict_start %u predict_cost %u cpu %u on thread %u\n",
-                        ei.m_mtaskId, ei.m_startTime - tickStart, (ei.m_endTime - ei.m_startTime),
-                        ei.m_predictStart, ei.m_predictCost, ei.m_cpu, thread_id);
-                break;
-            default: assert(false); break;  // LCOV_EXCL_LINE
-            }
-        }
-    }
-    fprintf(fp, "VLPROF stat ticks %" PRIu64 "\n", tickEnd - tickStart);
-
-    std::fclose(fp);
 }
@@ -24,6 +24,7 @@
 #define VERILATOR_VERILATED_THREADS_H_

 #include "verilatedos.h"
+
 #include "verilated.h"  // for VerilatedMutex and clang annotations

 #ifndef VL_THREADED
@@ -35,19 +36,24 @@
 #error "verilated_threads.h/cpp expected VL_THREADED (from verilator --threads)"
 #endif

+#include <atomic>
 #include <condition_variable>
 #include <set>
+#include <thread>
 #include <vector>

 // clang-format off
 #if defined(__linux)
 # include <sched.h>  // For sched_getcpu()
 #endif
-#if defined(__APPLE__)
+#if defined(__APPLE__) && !defined(__arm64__)
 # include <cpuid.h>  // For __cpuid_count()
 #endif
 // clang-format on

+class VlExecutionProfiler;
+class VlThreadPool;
+
 // VlMTaskVertex and VlThreadpool will work with multiple model class types.
 // Since the type is opaque to VlMTaskVertex and VlThreadPool, represent it
 // as a void* here.
@@ -58,7 +64,7 @@ using VlExecFnp = void (*)(VlSelfP, bool);
 // Track dependencies for a single MTask.
 class VlMTaskVertex final {
    // MEMBERS
-    static std::atomic<vluint64_t> s_yields;  // Statistics
+    static std::atomic<uint64_t> s_yields;  // Statistics

    // On even cycles, _upstreamDepsDone increases as upstream
    // dependencies complete. When it reaches _upstreamDepCount,
@@ -76,8 +82,8 @@ class VlMTaskVertex final {
    // during done-notification. Nobody's quantified that cost though.
    // If we were really serious about shrinking this class, we could
    // use 16-bit types here...)
-    std::atomic<vluint32_t> m_upstreamDepsDone;
-    const vluint32_t m_upstreamDepCount;
+    std::atomic<uint32_t> m_upstreamDepsDone;
+    const uint32_t m_upstreamDepCount;

 public:
    // CONSTRUCTORS
@@ -85,10 +91,10 @@ public:
    // 'upstreamDepCount' is the number of upstream MTaskVertex's
    // that must notify this MTaskVertex before it will become ready
    // to run.
-    explicit VlMTaskVertex(vluint32_t upstreamDepCount);
+    explicit VlMTaskVertex(uint32_t upstreamDepCount);
    ~VlMTaskVertex() = default;

-    static vluint64_t yields() { return s_yields; }
+    static uint64_t yields() { return s_yields; }
    static void yieldThread() {
        ++s_yields;  // Statistics
        std::this_thread::yield();
@@ -97,24 +103,24 @@ public:
    // Upstream mtasks must call this when they complete.
    // Returns true when the current MTaskVertex becomes ready to execute,
    // false while it's still waiting on more dependencies.
-    inline bool signalUpstreamDone(bool evenCycle) {
+    bool signalUpstreamDone(bool evenCycle) {
        if (evenCycle) {
-            const vluint32_t upstreamDepsDone
+            const uint32_t upstreamDepsDone
                = 1 + m_upstreamDepsDone.fetch_add(1, std::memory_order_release);
            assert(upstreamDepsDone <= m_upstreamDepCount);
            return (upstreamDepsDone == m_upstreamDepCount);
        } else {
-            const vluint32_t upstreamDepsDone_prev
+            const uint32_t upstreamDepsDone_prev
                = m_upstreamDepsDone.fetch_sub(1, std::memory_order_release);
            assert(upstreamDepsDone_prev > 0);
            return (upstreamDepsDone_prev == 1);
        }
    }
-    inline bool areUpstreamDepsDone(bool evenCycle) const {
-        const vluint32_t target = evenCycle ? m_upstreamDepCount : 0;
+    bool areUpstreamDepsDone(bool evenCycle) const {
+        const uint32_t target = evenCycle ? m_upstreamDepCount : 0;
        return m_upstreamDepsDone.load(std::memory_order_acquire) == target;
    }
-    inline void waitUntilUpstreamDone(bool evenCycle) const {
+    void waitUntilUpstreamDone(bool evenCycle) const {
        unsigned ct = 0;
        while (VL_UNLIKELY(!areUpstreamDepsDone(evenCycle))) {
            VL_CPU_RELAX();
@@ -127,77 +133,14 @@ public:
    }
 };

-// Profiling support
-class VlProfileRec final {
-protected:
-    friend class VlThreadPool;
-    enum VlProfileE { TYPE_MTASK_RUN, TYPE_EVAL, TYPE_EVAL_LOOP, TYPE_BARRIER };
-    // Layout below allows efficient packing.
-    // Leave endTime first, so no math needed to calculate address in endRecord
-    vluint64_t m_endTime = 0;  // Tick at end of execution
-    vluint64_t m_startTime = 0;  // Tick at start of execution
-    vluint32_t m_mtaskId = 0;  // Mtask we're logging
-    vluint32_t m_predictStart = 0;  // Time scheduler predicted would start
-    vluint32_t m_predictCost = 0;  // How long scheduler predicted would take
-    VlProfileE m_type = TYPE_BARRIER;  // Record type
-    unsigned m_cpu;  // Execution CPU number (at start anyways)
-public:
-    class Barrier {};
-    VlProfileRec() = default;
-    explicit VlProfileRec(Barrier) { m_cpu = getcpu(); }
-    void startEval(vluint64_t time) {
-        m_type = VlProfileRec::TYPE_EVAL;
-        m_startTime = time;
-        m_cpu = getcpu();
-    }
-    void startEvalLoop(vluint64_t time) {
-        m_type = VlProfileRec::TYPE_EVAL_LOOP;
-        m_startTime = time;
-        m_cpu = getcpu();
-    }
-    void startRecord(vluint64_t time, vluint32_t mtask, vluint32_t predictStart,
-                     vluint32_t predictCost) {
-        m_type = VlProfileRec::TYPE_MTASK_RUN;
-        m_mtaskId = mtask;
-        m_predictStart = predictStart;
-        m_predictCost = predictCost;
-        m_startTime = time;
-        m_cpu = getcpu();
-    }
-    void endRecord(vluint64_t time) { m_endTime = time; }
-    static int getcpu() {  // Return current executing CPU
-#if defined(__linux)
-        return sched_getcpu();
-#elif defined(__APPLE__)
-        vluint32_t info[4];
-        __cpuid_count(1, 0, info[0], info[1], info[2], info[3]);
-        // info[1] is EBX, bits 24-31 are APIC ID
-        if ((info[3] & (1 << 9)) == 0) {
-            return -1;  // no APIC on chip
-        } else {
-            return (unsigned)info[1] >> 24;
-        }
-#elif defined(_WIN32)
-        return GetCurrentProcessorNumber();
-#else
-        return 0;
-#endif
-    }
-};
-
-class VlThreadPool;
-
 class VlWorkerThread final {
 private:
    // TYPES
    struct ExecRec {
-        VlExecFnp m_fnp;  // Function to execute
-        VlSelfP m_selfp;  // Symbol table to execute
-        bool m_evenCycle;  // Even/odd for flag alternation
-        ExecRec()
-            : m_fnp{nullptr}
-            , m_selfp{nullptr}
-            , m_evenCycle{false} {}
+        VlExecFnp m_fnp = nullptr;  // Function to execute
+        VlSelfP m_selfp = nullptr;  // Symbol table to execute
+        bool m_evenCycle = false;  // Even/odd for flag alternation
+        ExecRec() = default;
        ExecRec(VlExecFnp fnp, VlSelfP selfp, bool evenCycle)
            : m_fnp{fnp}
            , m_selfp{selfp}
@@ -205,7 +148,7 @@ private:
    };

    // MEMBERS
-    VerilatedMutex m_mutex;
+    mutable VerilatedMutex m_mutex;
    std::condition_variable_any m_cv;
    // Only notify the condition_variable if the worker is waiting
    bool m_waiting VL_GUARDED_BY(m_mutex) = false;
@@ -217,28 +160,24 @@ private:
    // Store the size atomically, so we can spin wait
    std::atomic<size_t> m_ready_size;

-    VlThreadPool* const m_poolp;  // Our associated thread pool
-
-    const bool m_profiling;  // Is profiling enabled?
-    std::atomic<bool> m_exiting;  // Worker thread should exit
    std::thread m_cthread;  // Underlying C++ thread record
-    VerilatedContext* const m_contextp;  // Context for spawned thread

    VL_UNCOPYABLE(VlWorkerThread);

 public:
    // CONSTRUCTORS
-    explicit VlWorkerThread(VlThreadPool* poolp, VerilatedContext* contextp, bool profiling);
+    explicit VlWorkerThread(VerilatedContext* contextp);
    ~VlWorkerThread();

    // METHODS
-    inline void dequeWork(ExecRec* workp) VL_MT_SAFE_EXCLUDES(m_mutex) {
+    template <bool SpinWait>
+    void dequeWork(ExecRec* workp) VL_MT_SAFE_EXCLUDES(m_mutex) {
        // Spin for a while, waiting for new data
-        for (int i = 0; i < VL_LOCK_SPINS; ++i) {
-            if (VL_LIKELY(m_ready_size.load(std::memory_order_relaxed))) {  //
-                break;
+        if VL_CONSTEXPR_CXX17 (SpinWait) {
+            for (unsigned i = 0; i < VL_LOCK_SPINS; ++i) {
+                if (VL_LIKELY(m_ready_size.load(std::memory_order_relaxed))) break;
+                VL_CPU_RELAX();
            }
-            VL_CPU_RELAX();
        }
        VerilatedLockGuard lock{m_mutex};
        while (m_ready.empty()) {
@@ -252,8 +191,7 @@ public:
        m_ready.erase(m_ready.begin());
        m_ready_size.fetch_sub(1, std::memory_order_relaxed);
    }
-    inline void wakeUp() { addTask(nullptr, nullptr, false); }
-    inline void addTask(VlExecFnp fnp, VlSelfP selfp, bool evenCycle)
+    void addTask(VlExecFnp fnp, VlSelfP selfp, bool evenCycle = false)
        VL_MT_SAFE_EXCLUDES(m_mutex) {
        bool notify;
        {
@@ -264,55 +202,33 @@ public:
        }
        if (notify) m_cv.notify_one();
    }
+
+    void shutdown();  // Finish current tasks, then terminate thread
+    void wait();  // Blocks calling thread until all tasks complete in this thread
+
    void workerLoop();
-    static void startWorker(VlWorkerThread* workerp);
+    static void startWorker(VlWorkerThread* workerp, VerilatedContext* contextp);
 };

-class VlThreadPool final {
-    // TYPES
-    using ProfileTrace = std::vector<VlProfileRec>;
-
+class VlThreadPool final : public VerilatedVirtualBase {
    // MEMBERS
    std::vector<VlWorkerThread*> m_workers;  // our workers
-    const bool m_profiling;  // is profiling enabled?
-
-    // Support profiling -- we can append records of profiling events
-    // to this vector with very low overhead, and then dump them out
-    // later. This prevents the overhead of printf/malloc/IO from
-    // corrupting the profiling data. It's super cheap to append
-    // a VlProfileRec struct on the end of a pre-allocated vector;
-    // this is the only cost we pay in real-time during a profiling cycle.
-    // Internal note: Globals may multi-construct, see verilated.cpp top.
-    static VL_THREAD_LOCAL ProfileTrace* t_profilep;
-    std::set<ProfileTrace*> m_allProfiles VL_GUARDED_BY(m_mutex);
-    VerilatedMutex m_mutex;

 public:
    // CONSTRUCTORS
    // Construct a thread pool with 'nThreads' dedicated threads. The thread
    // pool will create these threads and make them available to execute tasks
    // via this->workerp(index)->addTask(...)
-    VlThreadPool(VerilatedContext* contextp, int nThreads, bool profiling);
-    ~VlThreadPool();
+    VlThreadPool(VerilatedContext* contextp, unsigned nThreads);
+    ~VlThreadPool() override;

    // METHODS
-    inline int numThreads() const { return m_workers.size(); }
-    inline VlWorkerThread* workerp(int index) {
+    int numThreads() const { return m_workers.size(); }
+    VlWorkerThread* workerp(int index) {
        assert(index >= 0);
        assert(index < m_workers.size());
        return m_workers[index];
    }
-    inline VlProfileRec* profileAppend() {
-        t_profilep->emplace_back();
-        return &(t_profilep->back());
-    }
-    void profileAppendAll(const VlProfileRec& rec) VL_MT_SAFE_EXCLUDES(m_mutex);
-    void profileDump(const char* filenamep, vluint64_t tickStart, vluint64_t tickEnd)
-        VL_MT_SAFE_EXCLUDES(m_mutex);
-    // In profiling mode, each executing thread must call
-    // this once to setup profiling state:
-    void setupProfilingClientThread() VL_MT_SAFE_EXCLUDES(m_mutex);
-    void tearDownProfilingClientThread();

 private:
    VL_UNCOPYABLE(VlThreadPool);
@@ -27,26 +27,36 @@
 #include "verilated.h"
 #include "verilated_trace_defs.h"

+#include <bitset>
+#include <condition_variable>
 #include <memory>
 #include <string>
+#include <unordered_map>
+#include <unordered_set>
 #include <vector>

-#ifdef VL_TRACE_THREADED
-# include <condition_variable>
+#ifdef VL_THREADED
 # include <deque>
 # include <thread>
 #endif

 // clang-format on

-#ifdef VL_TRACE_THREADED
+class VlThreadPool;
+template <class T_Buffer>
+class VerilatedTraceBuffer;
+template <class T_Buffer>
+class VerilatedTraceOffloadBuffer;
+
+#ifdef VL_THREADED
 //=============================================================================
-// Threaded tracing
+// Offloaded tracing

 // A simple synchronized first in first out queue
-template <class T> class VerilatedThreadQueue final {  // LCOV_EXCL_LINE  // lcov bug
+template <class T>
+class VerilatedThreadQueue final {  // LCOV_EXCL_LINE  // lcov bug
 private:
-    VerilatedMutex m_mutex;  // Protects m_queue
+    mutable VerilatedMutex m_mutex;  // Protects m_queue
    std::condition_variable_any m_cv;
    std::deque<T> m_queue VL_GUARDED_BY(m_mutex);

@@ -87,11 +97,11 @@ public:

 // Commands used by thread tracing. Anonymous enum in class, as we want
 // it scoped, but we also want the automatic conversion to integer types.
-class VerilatedTraceCommand final {
+class VerilatedTraceOffloadCommand final {
 public:
    // These must all fit in 4 bit at the moment, as the tracing routines
    // pack parameters in the top bits.
-    enum : vluint8_t {
+    enum : uint8_t {
        CHG_BIT_0 = 0x0,
        CHG_BIT_1 = 0x1,
        CHG_CDATA = 0x2,
@@ -101,36 +111,65 @@ public:
        CHG_WDATA = 0x6,
        CHG_DOUBLE = 0x8,
        // TODO: full..
-        TIME_CHANGE = 0xd,
+        TIME_CHANGE = 0xc,
+        TRACE_BUFFER = 0xd,
        END = 0xe,  // End of buffer
        SHUTDOWN = 0xf  // Shutdown worker thread, also marks end of buffer
    };
 };
 #endif

+//=============================================================================
+// VerilatedTraceConfig
+
+// Simple data representing trace configuration required by generated models.
+class VerilatedTraceConfig final {
+public:
+    const bool m_useParallel;  // Use parallel tracing
+    const bool m_useOffloading;  // Offloading trace rendering
+    const bool m_useFstWriterThread;  // Use the separate FST writer thread
+
+    VerilatedTraceConfig(bool useParallel, bool useOffloading, bool useFstWriterThread)
+        : m_useParallel{useParallel}
+        , m_useOffloading{useOffloading}
+        , m_useFstWriterThread{useFstWriterThread} {}
+};
+
 //=============================================================================
 // VerilatedTrace

-// VerilatedTrace uses F-bounded polymorphism to access duck-typed
-// implementations in the format specific derived class, which must be passed
-// as the type parameter T_Derived
-template <class T_Derived> class VerilatedTrace VL_NOT_FINAL {
+// T_Trace is the format specific subclass of VerilatedTrace.
+// T_Buffer is the format specific base class of VerilatedTraceBuffer.
+template <class T_Trace, class T_Buffer>
+class VerilatedTrace VL_NOT_FINAL {
 public:
+    using Buffer = VerilatedTraceBuffer<T_Buffer>;
+    using OffloadBuffer = VerilatedTraceOffloadBuffer<T_Buffer>;
+
    //=========================================================================
    // Generic tracing internals

-    using initCb_t = void (*)(void*, T_Derived*, vluint32_t);  // Type of init callbacks
-    using dumpCb_t = void (*)(void*, T_Derived*);  // Type of all but init callbacks
+    using initCb_t = void (*)(void*, T_Trace*, uint32_t);  // Type of init callbacks
+    using dumpCb_t = void (*)(void*, Buffer*);  // Type of dump callbacks
+    using dumpOffloadCb_t = void (*)(void*, OffloadBuffer*);  // Type of offload dump callbacks
+    using cleanupCb_t = void (*)(void*, T_Trace*);  // Type of cleanup callbacks

 private:
+    // Give the buffer (both base and derived) access to the private bits
+    friend T_Buffer;
+    friend Buffer;
+    friend OffloadBuffer;
+
    struct CallbackRecord {
        // Note: would make these fields const, but some old STL implementations
        // (the one in Ubuntu 14.04 with GCC 4.8.4 in particular) use the
        // assignment operator on inserting into collections, so they don't work
        // with const fields...
-        union {
-            initCb_t m_initCb;  // The callback function
-            dumpCb_t m_dumpCb;  // The callback function
+        union {  // The callback
+            initCb_t m_initCb;
+            dumpCb_t m_dumpCb;
+            dumpOffloadCb_t m_dumpOffloadCb;
+            cleanupCb_t m_cleanupCb;
        };
        void* m_userp;  // The user pointer to pass to the callback (the symbol table)
        CallbackRecord(initCb_t cb, void* userp)
@@ -139,67 +178,110 @@ private:
        CallbackRecord(dumpCb_t cb, void* userp)
            : m_dumpCb{cb}
            , m_userp{userp} {}
+        CallbackRecord(dumpOffloadCb_t cb, void* userp)
+            : m_dumpOffloadCb{cb}
+            , m_userp{userp} {}
+        CallbackRecord(cleanupCb_t cb, void* userp)
+            : m_cleanupCb{cb}
+            , m_userp{userp} {}
    };

-    vluint32_t* m_sigs_oldvalp;  // Old value store
-    vluint64_t m_timeLastDump;  // Last time we did a dump
-    std::vector<CallbackRecord> m_initCbs;  // Routines to initialize traciong
-    std::vector<CallbackRecord> m_fullCbs;  // Routines to perform full dump
-    std::vector<CallbackRecord> m_chgCbs;  // Routines to perform incremental dump
-    std::vector<CallbackRecord> m_cleanupCbs;  // Routines to call at the end of dump
-    bool m_fullDump;  // Whether a full dump is required on the next call to 'dump'
-    vluint32_t m_nextCode;  // Next code number to assign
-    vluint32_t m_numSignals;  // Number of distinct signals
-    vluint32_t m_maxBits;  // Number of bits in the widest signal
-    std::vector<std::string> m_namePrefixStack{""};  // Path prefixes to add to signal names
-    char m_scopeEscape;
-    double m_timeRes;  // Time resolution (ns/ms etc)
-    double m_timeUnit;  // Time units (ns/ms etc)
+    bool m_offload = false;  // Use the offload thread (ignored if !VL_THREADED)
+    bool m_parallel = false;  // Use parallel tracing (ignored if !VL_THREADED)

-    void addCallbackRecord(std::vector<CallbackRecord>& cbVec, CallbackRecord& cbRec)
+#ifdef VL_THREADED
+    struct ParallelWorkerData {
+        const dumpCb_t m_cb;  // The callback
+        void* const m_userp;  // The use pointer to pass to the callback
+        Buffer* const m_bufp;  // The buffer pointer to pass to the callback
+        std::atomic<bool> m_ready{false};  // The ready flag
+        mutable VerilatedMutex m_mutex;  // Mutex for suspension until ready
+        std::condition_variable_any m_cv;  // Condition variable for suspension
+        bool m_waiting VL_GUARDED_BY(m_mutex) = false;  // Whether a thread is suspended in wait()
+
+        void wait();
+
+        ParallelWorkerData(dumpCb_t cb, void* userp, Buffer* bufp)
+            : m_cb{cb}
+            , m_userp{userp}
+            , m_bufp{bufp} {}
+    };
+
+    // Passed a ParallelWorkerData*, second argument is ignored
+    static void parallelWorkerTask(void*, bool);
+#endif
+
+protected:
+    uint32_t* m_sigs_oldvalp = nullptr;  // Previous value store
+    EData* m_sigs_enabledp = nullptr;  // Bit vector of enabled codes (nullptr = all on)
+private:
+    std::vector<bool> m_sigs_enabledVec;  // Staging for m_sigs_enabledp
+    std::vector<CallbackRecord> m_initCbs;  // Routines to initialize tracing
+    std::vector<CallbackRecord> m_fullCbs;  // Routines to perform full dump
+    std::vector<CallbackRecord> m_fullOffloadCbs;  // Routines to perform offloaded full dump
+    std::vector<CallbackRecord> m_chgCbs;  // Routines to perform incremental dump
+    std::vector<CallbackRecord> m_chgOffloadCbs;  // Routines to perform offloaded incremental dump
+    std::vector<CallbackRecord> m_cleanupCbs;  // Routines to call at the end of dump
+    bool m_fullDump = true;  // Whether a full dump is required on the next call to 'dump'
+    uint32_t m_nextCode = 0;  // Next code number to assign
+    uint32_t m_numSignals = 0;  // Number of distinct signals
+    uint32_t m_maxBits = 0;  // Number of bits in the widest signal
+    std::vector<std::string> m_namePrefixStack{""};  // Path prefixes to add to signal names
+    std::vector<std::pair<int, std::string>> m_dumpvars;  // dumpvar() entries
+    char m_scopeEscape = '.';
+    double m_timeRes = 1e-9;  // Time resolution (ns/ms etc)
+    double m_timeUnit = 1e-0;  // Time units (ns/ms etc)
+    uint64_t m_timeLastDump = 0;  // Last time we did a dump
+    bool m_didSomeDump = false;  // Did at least one dump (i.e.: m_timeLastDump is valid)
+    VerilatedContext* m_contextp = nullptr;  // The context used by the traced models
+    std::unordered_set<const VerilatedModel*> m_models;  // The collection of models being traced
+
+    void addCallbackRecord(std::vector<CallbackRecord>& cbVec, CallbackRecord&& cbRec)
        VL_MT_SAFE_EXCLUDES(m_mutex);

-    // Equivalent to 'this' but is of the sub-type 'T_Derived*'. Use 'self()->'
+    // Equivalent to 'this' but is of the sub-type 'T_Trace*'. Use 'self()->'
    // to access duck-typed functions to avoid a virtual function call.
-    T_Derived* self() { return static_cast<T_Derived*>(this); }
+    T_Trace* self() { return static_cast<T_Trace*>(this); }
+
+    void runCallbacks(const std::vector<CallbackRecord>& cbVec);
+    void runOffloadedCallbacks(const std::vector<CallbackRecord>& cbVec);

    // Flush any remaining data for this file
    static void onFlush(void* selfp) VL_MT_UNSAFE_ONE;
    // Close the file on termination
    static void onExit(void* selfp) VL_MT_UNSAFE_ONE;

-#ifdef VL_TRACE_THREADED
-    // Number of total trace buffers that have been allocated
-    vluint32_t m_numTraceBuffers;
-
-    // Size of trace buffers
-    size_t m_traceBufferSize;
-
+#ifdef VL_THREADED
+    // Number of total offload buffers that have been allocated
+    uint32_t m_numOffloadBuffers = 0;
+    // Size of offload buffers
+    size_t m_offloadBufferSize = 0;
    // Buffers handed to worker for processing
-    VerilatedThreadQueue<vluint32_t*> m_buffersToWorker;
+    VerilatedThreadQueue<uint32_t*> m_offloadBuffersToWorker;
    // Buffers returned from worker after processing
-    VerilatedThreadQueue<vluint32_t*> m_buffersFromWorker;
-
-    // Get a new trace buffer that can be populated. May block if none available
-    vluint32_t* getTraceBuffer();
+    VerilatedThreadQueue<uint32_t*> m_offloadBuffersFromWorker;

+protected:
    // Write pointer into current buffer
-    vluint32_t* m_traceBufferWritep;
+    uint32_t* m_offloadBufferWritep = nullptr;
+    // End of offload buffer
+    uint32_t* m_offloadBufferEndp = nullptr;

-    // End of trace buffer
-    vluint32_t* m_traceBufferEndp;
-
-    // The worker thread itself
+private:
+    // The offload worker thread itself
    std::unique_ptr<std::thread> m_workerThread;

-    // The function executed by the worker thread
-    void workerThreadMain();
+    // Get a new offload buffer that can be populated. May block if none available
+    uint32_t* getOffloadBuffer();

-    // Wait until given buffer is placed in m_buffersFromWorker
-    void waitForBuffer(const vluint32_t* bufferp);
+    // The function executed by the offload worker thread
+    void offloadWorkerThreadMain();
+
+    // Wait until given offload buffer is placed in m_offloadBuffersFromWorker
+    void waitForOffloadBuffer(const uint32_t* bufferp);

    // Shut down and join worker, if it's running, otherwise do nothing
-    void shutdownWorker();
+    void shutdownOffloadWorker();
 #endif

    // CONSTRUCTORS
@@ -209,13 +291,12 @@ protected:
    //=========================================================================
    // Internals available to format specific implementations

-    VerilatedMutex m_mutex;  // Ensure dump() etc only called from single thread
+    mutable VerilatedMutex m_mutex;  // Ensure dump() etc only called from single thread

-    vluint32_t nextCode() const { return m_nextCode; }
-    vluint32_t numSignals() const { return m_numSignals; }
-    vluint32_t maxBits() const { return m_maxBits; }
+    uint32_t nextCode() const { return m_nextCode; }
+    uint32_t numSignals() const { return m_numSignals; }
+    uint32_t maxBits() const { return m_maxBits; }
    void fullDump(bool value) { m_fullDump = value; }
-    vluint64_t timeLastDump() { return m_timeLastDump; }

    double timeRes() const { return m_timeRes; }
    double timeUnit() const { return m_timeUnit; }
@@ -223,7 +304,8 @@ protected:

    void traceInit() VL_MT_UNSAFE;

-    void declCode(vluint32_t code, vluint32_t bits, bool tri);
+    // Declare new signal and return true if enabled
+    bool declCode(uint32_t code, const char* namep, uint32_t bits, bool tri);

    // Is this an escape?
    bool isScopeEscape(char c) { return std::isspace(c) || c == m_scopeEscape; }
@@ -235,17 +317,32 @@ protected:
    void closeBase();
    void flushBase();

+#ifdef VL_THREADED
+    bool offload() const { return m_offload; }
+    bool parallel() const { return m_parallel; }
+#else
+    static constexpr bool offload() { return false; }
+    static constexpr bool parallel() { return false; }
+#endif
+
    //=========================================================================
    // Virtual functions to be provided by the format specific implementation

    // Called when the trace moves forward to a new time point
-    virtual void emitTimeChange(vluint64_t timeui) = 0;
+    virtual void emitTimeChange(uint64_t timeui) = 0;

    // These hooks are called before a full or change based dump is produced.
    // The return value indicates whether to proceed with the dump.
    virtual bool preFullDump() = 0;
    virtual bool preChangeDump() = 0;

+    // Trace buffer management
+    virtual Buffer* getTraceBuffer() = 0;
+    virtual void commitTraceBuffer(Buffer*) = 0;
+
+    // Configure sub-class
+    virtual void configure(const VerilatedTraceConfig&) = 0;
+
 public:
    //=========================================================================
    // External interface to client code
@@ -259,23 +356,58 @@ public:
    // Set time resolution (s/ms, defaults to ns)
    void set_time_resolution(const char* unitp) VL_MT_SAFE;
    void set_time_resolution(const std::string& unit) VL_MT_SAFE;
+    // Set variables to dump, using $dumpvars format
+    // If level = 0, dump everything and hier is then ignored
+    void dumpvars(int level, const std::string& hier) VL_MT_SAFE;

    // Call
-    void dump(vluint64_t timeui) VL_MT_SAFE_EXCLUDES(m_mutex);
+    void dump(uint64_t timeui) VL_MT_SAFE_EXCLUDES(m_mutex);
+
+    //=========================================================================
+    // Internal interface to Verilator generated code

    //=========================================================================
    // Non-hot path internal interface to Verilator generated code

+    void addModel(VerilatedModel*) VL_MT_SAFE_EXCLUDES(m_mutex);
    void addInitCb(initCb_t cb, void* userp) VL_MT_SAFE;
    void addFullCb(dumpCb_t cb, void* userp) VL_MT_SAFE;
+    void addFullCb(dumpOffloadCb_t cb, void* userp) VL_MT_SAFE;
    void addChgCb(dumpCb_t cb, void* userp) VL_MT_SAFE;
-    void addCleanupCb(dumpCb_t cb, void* userp) VL_MT_SAFE;
+    void addChgCb(dumpOffloadCb_t cb, void* userp) VL_MT_SAFE;
+    void addCleanupCb(cleanupCb_t cb, void* userp) VL_MT_SAFE;

    void scopeEscape(char flag) { m_scopeEscape = flag; }

    void pushNamePrefix(const std::string&);
    void popNamePrefix(unsigned count = 1);
+};

+//=============================================================================
+// VerilatedTraceBuffer
+
+// T_Buffer is the format specific base class of VerilatedTraceBuffer.
+// The format-specific hot-path methods use duck-typing via T_Buffer for performance.
+template <class T_Buffer>
+class VerilatedTraceBuffer VL_NOT_FINAL : public T_Buffer {
+protected:
+    // Type of the owner trace file
+    using Trace = typename std::remove_cv<
+        typename std::remove_reference<decltype(T_Buffer::m_owner)>::type>::type;
+
+    static_assert(std::has_virtual_destructor<T_Buffer>::value, "");
+    static_assert(std::is_base_of<VerilatedTrace<Trace, T_Buffer>, Trace>::value, "");
+
+    friend Trace;  // Give the trace file access to the private bits
+    friend std::default_delete<VerilatedTraceBuffer<T_Buffer>>;
+
+    uint32_t* const m_sigs_oldvalp;  // Previous value store
+    EData* const m_sigs_enabledp;  // Bit vector of enabled codes (nullptr = all on)
+
+    explicit VerilatedTraceBuffer(Trace& owner);
+    ~VerilatedTraceBuffer() override = default;
+
+public:
    //=========================================================================
    // Hot path internal interface to Verilator generated code

@@ -285,108 +417,51 @@ public:
    // these here, but we cannot afford dynamic dispatch for calling these as
    // this is very hot code during tracing.

-    // duck-typed void emitBit(vluint32_t code, CData newval) = 0;
-    // duck-typed void emitCData(vluint32_t code, CData newval, int bits) = 0;
-    // duck-typed void emitSData(vluint32_t code, SData newval, int bits) = 0;
-    // duck-typed void emitIData(vluint32_t code, IData newval, int bits) = 0;
-    // duck-typed void emitQData(vluint32_t code, QData newval, int bits) = 0;
-    // duck-typed void emitWData(vluint32_t code, const WData* newvalp, int bits) = 0;
-    // duck-typed void emitDouble(vluint32_t code, double newval) = 0;
+    // duck-typed void emitBit(uint32_t code, CData newval) = 0;
+    // duck-typed void emitCData(uint32_t code, CData newval, int bits) = 0;
+    // duck-typed void emitSData(uint32_t code, SData newval, int bits) = 0;
+    // duck-typed void emitIData(uint32_t code, IData newval, int bits) = 0;
+    // duck-typed void emitQData(uint32_t code, QData newval, int bits) = 0;
+    // duck-typed void emitWData(uint32_t code, const WData* newvalp, int bits) = 0;
+    // duck-typed void emitDouble(uint32_t code, double newval) = 0;

-    vluint32_t* oldp(vluint32_t code) { return m_sigs_oldvalp + code; }
+    VL_ATTR_ALWINLINE uint32_t* oldp(uint32_t code) { return m_sigs_oldvalp + code; }

    // Write to previous value buffer value and emit trace entry.
-    void fullBit(vluint32_t* oldp, CData newval);
-    void fullCData(vluint32_t* oldp, CData newval, int bits);
-    void fullSData(vluint32_t* oldp, SData newval, int bits);
-    void fullIData(vluint32_t* oldp, IData newval, int bits);
-    void fullQData(vluint32_t* oldp, QData newval, int bits);
-    void fullWData(vluint32_t* oldp, const WData* newvalp, int bits);
-    void fullDouble(vluint32_t* oldp, double newval);
+    void fullBit(uint32_t* oldp, CData newval);
+    void fullCData(uint32_t* oldp, CData newval, int bits);
+    void fullSData(uint32_t* oldp, SData newval, int bits);
+    void fullIData(uint32_t* oldp, IData newval, int bits);
+    void fullQData(uint32_t* oldp, QData newval, int bits);
+    void fullWData(uint32_t* oldp, const WData* newvalp, int bits);
+    void fullDouble(uint32_t* oldp, double newval);

-#ifdef VL_TRACE_THREADED
-    // Threaded tracing. Just dump everything in the trace buffer
-    inline void chgBit(vluint32_t code, CData newval) {
-        m_traceBufferWritep[0] = VerilatedTraceCommand::CHG_BIT_0 | newval;
-        m_traceBufferWritep[1] = code;
-        m_traceBufferWritep += 2;
-        VL_DEBUG_IF(assert(m_traceBufferWritep <= m_traceBufferEndp););
-    }
-    inline void chgCData(vluint32_t code, CData newval, int bits) {
-        m_traceBufferWritep[0] = (bits << 4) | VerilatedTraceCommand::CHG_CDATA;
-        m_traceBufferWritep[1] = code;
-        m_traceBufferWritep[2] = newval;
-        m_traceBufferWritep += 3;
-        VL_DEBUG_IF(assert(m_traceBufferWritep <= m_traceBufferEndp););
-    }
-    inline void chgSData(vluint32_t code, SData newval, int bits) {
-        m_traceBufferWritep[0] = (bits << 4) | VerilatedTraceCommand::CHG_SDATA;
-        m_traceBufferWritep[1] = code;
-        m_traceBufferWritep[2] = newval;
-        m_traceBufferWritep += 3;
-        VL_DEBUG_IF(assert(m_traceBufferWritep <= m_traceBufferEndp););
-    }
-    inline void chgIData(vluint32_t code, IData newval, int bits) {
-        m_traceBufferWritep[0] = (bits << 4) | VerilatedTraceCommand::CHG_IDATA;
-        m_traceBufferWritep[1] = code;
-        m_traceBufferWritep[2] = newval;
-        m_traceBufferWritep += 3;
-        VL_DEBUG_IF(assert(m_traceBufferWritep <= m_traceBufferEndp););
-    }
-    inline void chgQData(vluint32_t code, QData newval, int bits) {
-        m_traceBufferWritep[0] = (bits << 4) | VerilatedTraceCommand::CHG_QDATA;
-        m_traceBufferWritep[1] = code;
-        *reinterpret_cast<QData*>(m_traceBufferWritep + 2) = newval;
-        m_traceBufferWritep += 4;
-        VL_DEBUG_IF(assert(m_traceBufferWritep <= m_traceBufferEndp););
-    }
-    inline void chgWData(vluint32_t code, const WData* newvalp, int bits) {
-        m_traceBufferWritep[0] = (bits << 4) | VerilatedTraceCommand::CHG_WDATA;
-        m_traceBufferWritep[1] = code;
-        m_traceBufferWritep += 2;
-        for (int i = 0; i < (bits + 31) / 32; ++i) { *m_traceBufferWritep++ = newvalp[i]; }
-        VL_DEBUG_IF(assert(m_traceBufferWritep <= m_traceBufferEndp););
-    }
-    inline void chgDouble(vluint32_t code, double newval) {
-        m_traceBufferWritep[0] = VerilatedTraceCommand::CHG_DOUBLE;
-        m_traceBufferWritep[1] = code;
-        // cppcheck-suppress invalidPointerCast
-        *reinterpret_cast<double*>(m_traceBufferWritep + 2) = newval;
-        m_traceBufferWritep += 4;
-        VL_DEBUG_IF(assert(m_traceBufferWritep <= m_traceBufferEndp););
-    }
-
-#define CHG(name) chg##name##Impl
-#else
-#define CHG(name) chg##name
-#endif
-
-    // In non-threaded mode, these are called directly by the trace callbacks,
-    // and are called chg*. In threaded mode, they are called by the worker
+    // In non-offload mode, these are called directly by the trace callbacks,
+    // and are called chg*. In offload mode, they are called by the worker
    // thread and are called chg*Impl

    // Check previous dumped value of signal. If changed, then emit trace entry
-    inline void CHG(Bit)(vluint32_t* oldp, CData newval) {
-        const vluint32_t diff = *oldp ^ newval;
+    VL_ATTR_ALWINLINE void chgBit(uint32_t* oldp, CData newval) {
+        const uint32_t diff = *oldp ^ newval;
        if (VL_UNLIKELY(diff)) fullBit(oldp, newval);
    }
-    inline void CHG(CData)(vluint32_t* oldp, CData newval, int bits) {
-        const vluint32_t diff = *oldp ^ newval;
+    VL_ATTR_ALWINLINE void chgCData(uint32_t* oldp, CData newval, int bits) {
+        const uint32_t diff = *oldp ^ newval;
        if (VL_UNLIKELY(diff)) fullCData(oldp, newval, bits);
    }
-    inline void CHG(SData)(vluint32_t* oldp, SData newval, int bits) {
-        const vluint32_t diff = *oldp ^ newval;
+    VL_ATTR_ALWINLINE void chgSData(uint32_t* oldp, SData newval, int bits) {
+        const uint32_t diff = *oldp ^ newval;
        if (VL_UNLIKELY(diff)) fullSData(oldp, newval, bits);
    }
-    inline void CHG(IData)(vluint32_t* oldp, IData newval, int bits) {
-        const vluint32_t diff = *oldp ^ newval;
+    VL_ATTR_ALWINLINE void chgIData(uint32_t* oldp, IData newval, int bits) {
+        const uint32_t diff = *oldp ^ newval;
        if (VL_UNLIKELY(diff)) fullIData(oldp, newval, bits);
    }
-    inline void CHG(QData)(vluint32_t* oldp, QData newval, int bits) {
-        const vluint64_t diff = *reinterpret_cast<QData*>(oldp) ^ newval;
+    VL_ATTR_ALWINLINE void chgQData(uint32_t* oldp, QData newval, int bits) {
+        const uint64_t diff = *reinterpret_cast<QData*>(oldp) ^ newval;
        if (VL_UNLIKELY(diff)) fullQData(oldp, newval, bits);
    }
-    inline void CHG(WData)(vluint32_t* oldp, const WData* newvalp, int bits) {
+    VL_ATTR_ALWINLINE void chgWData(uint32_t* oldp, const WData* newvalp, int bits) {
        for (int i = 0; i < (bits + 31) / 32; ++i) {
            if (VL_UNLIKELY(oldp[i] ^ newvalp[i])) {
                fullWData(oldp, newvalp, bits);
@@ -394,11 +469,85 @@ public:
            }
        }
    }
-    inline void CHG(Double)(vluint32_t* oldp, double newval) {
+    VL_ATTR_ALWINLINE void chgDouble(uint32_t* oldp, double newval) {
        // cppcheck-suppress invalidPointerCast
        if (VL_UNLIKELY(*reinterpret_cast<double*>(oldp) != newval)) fullDouble(oldp, newval);
    }
-
-#undef CHG
 };
+
+#ifdef VL_THREADED
+//=============================================================================
+// VerilatedTraceOffloadBuffer
+
+// T_Buffer is the format specific base class of VerilatedTraceBuffer.
+// The format-specific hot-path methods use duck-typing via T_Buffer for performance.
+template <class T_Buffer>
+class VerilatedTraceOffloadBuffer final : public VerilatedTraceBuffer<T_Buffer> {
+    using typename VerilatedTraceBuffer<T_Buffer>::Trace;
+
+    friend Trace;  // Give the trace file access to the private bits
+
+    uint32_t* m_offloadBufferWritep;  // Write pointer into current buffer
+    uint32_t* const m_offloadBufferEndp;  // End of offload buffer
+
+    explicit VerilatedTraceOffloadBuffer(Trace& owner);
+    ~VerilatedTraceOffloadBuffer() override = default;
+
+public:
+    //=========================================================================
+    // Hot path internal interface to Verilator generated code
+
+    // Offloaded tracing. Just dump everything in the offload buffer
+    void chgBit(uint32_t code, CData newval) {
+        m_offloadBufferWritep[0] = VerilatedTraceOffloadCommand::CHG_BIT_0 | newval;
+        m_offloadBufferWritep[1] = code;
+        m_offloadBufferWritep += 2;
+        VL_DEBUG_IF(assert(m_offloadBufferWritep <= m_offloadBufferEndp););
+    }
+    void chgCData(uint32_t code, CData newval, int bits) {
+        m_offloadBufferWritep[0] = (bits << 4) | VerilatedTraceOffloadCommand::CHG_CDATA;
+        m_offloadBufferWritep[1] = code;
+        m_offloadBufferWritep[2] = newval;
+        m_offloadBufferWritep += 3;
+        VL_DEBUG_IF(assert(m_offloadBufferWritep <= m_offloadBufferEndp););
+    }
+    void chgSData(uint32_t code, SData newval, int bits) {
+        m_offloadBufferWritep[0] = (bits << 4) | VerilatedTraceOffloadCommand::CHG_SDATA;
+        m_offloadBufferWritep[1] = code;
+        m_offloadBufferWritep[2] = newval;
+        m_offloadBufferWritep += 3;
+        VL_DEBUG_IF(assert(m_offloadBufferWritep <= m_offloadBufferEndp););
+    }
+    void chgIData(uint32_t code, IData newval, int bits) {
+        m_offloadBufferWritep[0] = (bits << 4) | VerilatedTraceOffloadCommand::CHG_IDATA;
+        m_offloadBufferWritep[1] = code;
+        m_offloadBufferWritep[2] = newval;
+        m_offloadBufferWritep += 3;
+        VL_DEBUG_IF(assert(m_offloadBufferWritep <= m_offloadBufferEndp););
+    }
+    void chgQData(uint32_t code, QData newval, int bits) {
+        m_offloadBufferWritep[0] = (bits << 4) | VerilatedTraceOffloadCommand::CHG_QDATA;
+        m_offloadBufferWritep[1] = code;
+        *reinterpret_cast<QData*>(m_offloadBufferWritep + 2) = newval;
+        m_offloadBufferWritep += 4;
+        VL_DEBUG_IF(assert(m_offloadBufferWritep <= m_offloadBufferEndp););
+    }
+    void chgWData(uint32_t code, const WData* newvalp, int bits) {
+        m_offloadBufferWritep[0] = (bits << 4) | VerilatedTraceOffloadCommand::CHG_WDATA;
+        m_offloadBufferWritep[1] = code;
+        m_offloadBufferWritep += 2;
+        for (int i = 0; i < (bits + 31) / 32; ++i) { *m_offloadBufferWritep++ = newvalp[i]; }
+        VL_DEBUG_IF(assert(m_offloadBufferWritep <= m_offloadBufferEndp););
+    }
+    void chgDouble(uint32_t code, double newval) {
+        m_offloadBufferWritep[0] = VerilatedTraceOffloadCommand::CHG_DOUBLE;
+        m_offloadBufferWritep[1] = code;
+        // cppcheck-suppress invalidPointerCast
+        *reinterpret_cast<double*>(m_offloadBufferWritep + 2) = newval;
+        m_offloadBufferWritep += 4;
+        VL_DEBUG_IF(assert(m_offloadBufferWritep <= m_offloadBufferEndp););
+    }
+};
+#endif
+
 #endif  // guard
@@ -1,693 +0,0 @@
-// -*- mode: C++; c-file-style: "cc-mode" -*-
-//=============================================================================
-//
-// Code available from: https://verilator.org
-//
-// Copyright 2001-2022 by Wilson Snyder. This program is free software; you
-// can redistribute it and/or modify it under the terms of either the GNU
-// Lesser General Public License Version 3 or the Perl Artistic License
-// Version 2.0.
-// SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
-//
-//=============================================================================
-///
-/// \file
-/// \brief Verilated common-format tracing implementation code
-///
-/// This file must be compiled and linked against all Verilated objects
-/// that use --trace.
-///
-/// Use "verilator --trace" to add this to the Makefile for the linker.
-///
-//=============================================================================
-
-// clang-format off
-
-#ifndef VL_CPPCHECK
-#ifndef VL_DERIVED_T
-# error "This file should be included in trace format implementations"
-#endif
-
-#include "verilated_intrinsics.h"
-#include "verilated_trace.h"
-
-#if 0
-# include <iostream>
-# define VL_TRACE_THREAD_DEBUG(msg) std::cout << "TRACE THREAD: " << msg << std::endl
-#else
-# define VL_TRACE_THREAD_DEBUG(msg)
-#endif
-
-// clang-format on
-
-//=============================================================================
-// Static utility functions
-
-static double timescaleToDouble(const char* unitp) {
-    char* endp = nullptr;
-    double value = std::strtod(unitp, &endp);
-    // On error so we allow just "ns" to return 1e-9.
-    if (value == 0.0 && endp == unitp) value = 1;
-    unitp = endp;
-    for (; *unitp && std::isspace(*unitp); unitp++) {}
-    switch (*unitp) {
-    case 's': value *= 1e0; break;
-    case 'm': value *= 1e-3; break;
-    case 'u': value *= 1e-6; break;
-    case 'n': value *= 1e-9; break;
-    case 'p': value *= 1e-12; break;
-    case 'f': value *= 1e-15; break;
-    case 'a': value *= 1e-18; break;
-    }
-    return value;
-}
-
-static std::string doubleToTimescale(double value) {
-    const char* suffixp = "s";
-    // clang-format off
-    if      (value >= 1e0)   { suffixp = "s"; value *= 1e0; }
-    else if (value >= 1e-3 ) { suffixp = "ms"; value *= 1e3; }
-    else if (value >= 1e-6 ) { suffixp = "us"; value *= 1e6; }
-    else if (value >= 1e-9 ) { suffixp = "ns"; value *= 1e9; }
-    else if (value >= 1e-12) { suffixp = "ps"; value *= 1e12; }
-    else if (value >= 1e-15) { suffixp = "fs"; value *= 1e15; }
-    else if (value >= 1e-18) { suffixp = "as"; value *= 1e18; }
-    // clang-format on
-    char valuestr[100];
-    VL_SNPRINTF(valuestr, 100, "%0.0f%s", value, suffixp);
-    return valuestr;  // Gets converted to string, so no ref to stack
-}
-
-#ifdef VL_TRACE_THREADED
-//=========================================================================
-// Buffer management
-
-template <> vluint32_t* VerilatedTrace<VL_DERIVED_T>::getTraceBuffer() {
-    vluint32_t* bufferp;
-    // Some jitter is expected, so some number of alternative trace buffers are
-    // required, but don't allocate more than 8 buffers.
-    if (m_numTraceBuffers < 8) {
-        // Allocate a new buffer if none is available
-        if (!m_buffersFromWorker.tryGet(bufferp)) {
-            ++m_numTraceBuffers;
-            // Note: over allocate a bit so pointer comparison is well defined
-            // if we overflow only by a small amount
-            bufferp = new vluint32_t[m_traceBufferSize + 16];
-        }
-    } else {
-        // Block until a buffer becomes available
-        bufferp = m_buffersFromWorker.get();
-    }
-    return bufferp;
-}
-
-template <> void VerilatedTrace<VL_DERIVED_T>::waitForBuffer(const vluint32_t* buffp) {
-    // Slow path code only called on flush/shutdown, so use a simple algorithm.
-    // Collect buffers from worker and stash them until we get the one we want.
-    std::deque<vluint32_t*> stash;
-    do { stash.push_back(m_buffersFromWorker.get()); } while (stash.back() != buffp);
-    // Now put them back in the queue, in the original order.
-    while (!stash.empty()) {
-        m_buffersFromWorker.put_front(stash.back());
-        stash.pop_back();
-    }
-}
-
-//=========================================================================
-// Worker thread
-
-template <> void VerilatedTrace<VL_DERIVED_T>::workerThreadMain() {
-    bool shutdown = false;
-
-    do {
-        vluint32_t* const bufferp = m_buffersToWorker.get();
-
-        VL_TRACE_THREAD_DEBUG("");
-        VL_TRACE_THREAD_DEBUG("Got buffer: " << bufferp);
-
-        const vluint32_t* readp = bufferp;
-
-        while (true) {
-            const vluint32_t cmd = readp[0];
-            const vluint32_t top = cmd >> 4;
-            // Always set this up, as it is almost always needed
-            vluint32_t* const oldp = m_sigs_oldvalp + readp[1];
-            // Note this increment needs to be undone on commands which do not
-            // actually contain a code, but those are the rare cases.
-            readp += 2;
-
-            switch (cmd & 0xF) {
-                //===
-                // CHG_* commands
-            case VerilatedTraceCommand::CHG_BIT_0:
-                VL_TRACE_THREAD_DEBUG("Command CHG_BIT_0 " << top);
-                chgBitImpl(oldp, 0);
-                continue;
-            case VerilatedTraceCommand::CHG_BIT_1:
-                VL_TRACE_THREAD_DEBUG("Command CHG_BIT_1 " << top);
-                chgBitImpl(oldp, 1);
-                continue;
-            case VerilatedTraceCommand::CHG_CDATA:
-                VL_TRACE_THREAD_DEBUG("Command CHG_CDATA " << top);
-                // Bits stored in bottom byte of command
-                chgCDataImpl(oldp, *readp, top);
-                readp += 1;
-                continue;
-            case VerilatedTraceCommand::CHG_SDATA:
-                VL_TRACE_THREAD_DEBUG("Command CHG_SDATA " << top);
-                // Bits stored in bottom byte of command
-                chgSDataImpl(oldp, *readp, top);
-                readp += 1;
-                continue;
-            case VerilatedTraceCommand::CHG_IDATA:
-                VL_TRACE_THREAD_DEBUG("Command CHG_IDATA " << top);
-                // Bits stored in bottom byte of command
-                chgIDataImpl(oldp, *readp, top);
-                readp += 1;
-                continue;
-            case VerilatedTraceCommand::CHG_QDATA:
-                VL_TRACE_THREAD_DEBUG("Command CHG_QDATA " << top);
-                // Bits stored in bottom byte of command
-                chgQDataImpl(oldp, *reinterpret_cast<const QData*>(readp), top);
-                readp += 2;
-                continue;
-            case VerilatedTraceCommand::CHG_WDATA:
-                VL_TRACE_THREAD_DEBUG("Command CHG_WDATA " << top);
-                chgWDataImpl(oldp, readp, top);
-                readp += VL_WORDS_I(top);
-                continue;
-            case VerilatedTraceCommand::CHG_DOUBLE:
-                VL_TRACE_THREAD_DEBUG("Command CHG_DOUBLE " << top);
-                chgDoubleImpl(oldp, *reinterpret_cast<const double*>(readp));
-                readp += 2;
-                continue;
-
-                //===
-                // Rare commands
-            case VerilatedTraceCommand::TIME_CHANGE:
-                VL_TRACE_THREAD_DEBUG("Command TIME_CHANGE " << top);
-                readp -= 1;  // No code in this command, undo increment
-                emitTimeChange(*reinterpret_cast<const vluint64_t*>(readp));
-                readp += 2;
-                continue;
-
-                //===
-                // Commands ending this buffer
-            case VerilatedTraceCommand::END: VL_TRACE_THREAD_DEBUG("Command END"); break;
-            case VerilatedTraceCommand::SHUTDOWN:
-                VL_TRACE_THREAD_DEBUG("Command SHUTDOWN");
-                shutdown = true;
-                break;
-
-            //===
-            // Unknown command
-            default: {  // LCOV_EXCL_START
-                VL_TRACE_THREAD_DEBUG("Command UNKNOWN");
-                VL_PRINTF_MT("Trace command: 0x%08x\n", cmd);
-                VL_FATAL_MT(__FILE__, __LINE__, "", "Unknown trace command");
-                break;
-            }  // LCOV_EXCL_STOP
-            }
-
-            // The above switch will execute 'continue' when necessary,
-            // so if we ever reach here, we are done with the buffer.
-            break;
-        }
-
-        VL_TRACE_THREAD_DEBUG("Returning buffer");
-
-        // Return buffer
-        m_buffersFromWorker.put(bufferp);
-    } while (VL_LIKELY(!shutdown));
-}
-
-template <> void VerilatedTrace<VL_DERIVED_T>::shutdownWorker() {
-    // If the worker thread is not running, done..
-    if (!m_workerThread) return;
-
-    // Hand an buffer with a shutdown command to the worker thread
-    vluint32_t* const bufferp = getTraceBuffer();
-    bufferp[0] = VerilatedTraceCommand::SHUTDOWN;
-    m_buffersToWorker.put(bufferp);
-    // Wait for it to return
-    waitForBuffer(bufferp);
-    // Join the thread and delete it
-    m_workerThread->join();
-    m_workerThread.reset(nullptr);
-}
-
-#endif
-
-//=============================================================================
-// Life cycle
-
-template <> void VerilatedTrace<VL_DERIVED_T>::closeBase() {
-#ifdef VL_TRACE_THREADED
-    shutdownWorker();
-    while (m_numTraceBuffers) {
-        delete[] m_buffersFromWorker.get();
-        --m_numTraceBuffers;
-    }
-#endif
-}
-
-template <> void VerilatedTrace<VL_DERIVED_T>::flushBase() {
-#ifdef VL_TRACE_THREADED
-    // Hand an empty buffer to the worker thread
-    vluint32_t* const bufferp = getTraceBuffer();
-    *bufferp = VerilatedTraceCommand::END;
-    m_buffersToWorker.put(bufferp);
-    // Wait for it to be returned. As the processing is in-order,
-    // this ensures all previous buffers have been processed.
-    waitForBuffer(bufferp);
-#endif
-}
-
-//=============================================================================
-// Callbacks to run on global events
-
-template <> void VerilatedTrace<VL_DERIVED_T>::onFlush(void* selfp) {
-    // This calls 'flush' on the derived class (which must then get any mutex)
-    reinterpret_cast<VL_DERIVED_T*>(selfp)->flush();
-}
-
-template <> void VerilatedTrace<VL_DERIVED_T>::onExit(void* selfp) {
-    // This calls 'close' on the derived class (which must then get any mutex)
-    reinterpret_cast<VL_DERIVED_T*>(selfp)->close();
-}
-
-//=============================================================================
-// VerilatedTrace
-
-template <>
-VerilatedTrace<VL_DERIVED_T>::VerilatedTrace()
-    : m_sigs_oldvalp{nullptr}
-    , m_timeLastDump{0}
-    , m_fullDump{true}
-    , m_nextCode{0}
-    , m_numSignals{0}
-    , m_maxBits{0}
-    , m_scopeEscape{'.'}
-    , m_timeRes{1e-9}
-    , m_timeUnit {
-    1e-9
-}
-#ifdef VL_TRACE_THREADED
-, m_numTraceBuffers { 0 }
-#endif
-{
-    set_time_unit(Verilated::threadContextp()->timeunitString());
-    set_time_resolution(Verilated::threadContextp()->timeprecisionString());
-}
-
-template <> VerilatedTrace<VL_DERIVED_T>::~VerilatedTrace() {
-    if (m_sigs_oldvalp) VL_DO_CLEAR(delete[] m_sigs_oldvalp, m_sigs_oldvalp = nullptr);
-    Verilated::removeFlushCb(VerilatedTrace<VL_DERIVED_T>::onFlush, this);
-    Verilated::removeExitCb(VerilatedTrace<VL_DERIVED_T>::onExit, this);
-#ifdef VL_TRACE_THREADED
-    closeBase();
-#endif
-}
-
-//=========================================================================
-// Internals available to format specific implementations
-
-template <> void VerilatedTrace<VL_DERIVED_T>::traceInit() VL_MT_UNSAFE {
-    // Note: It is possible to re-open a trace file (VCD in particular),
-    // so we must reset the next code here, but it must have the same number
-    // of codes on re-open
-    const vluint32_t expectedCodes = nextCode();
-    m_nextCode = 1;
-    m_numSignals = 0;
-    m_maxBits = 0;
-
-    // Call all initialize callbacks, which will:
-    // - Call decl* for each signal
-    // - Store the base code
-    for (vluint32_t i = 0; i < m_initCbs.size(); ++i) {
-        const CallbackRecord& cbr = m_initCbs[i];
-        cbr.m_initCb(cbr.m_userp, self(), nextCode());
-    }
-
-    if (expectedCodes && nextCode() != expectedCodes) {
-        VL_FATAL_MT(__FILE__, __LINE__, "",
-                    "Reopening trace file with different number of signals");
-    }
-
-    // Now that we know the number of codes, allocate space for the buffer
-    // holding previous signal values.
-    if (!m_sigs_oldvalp) m_sigs_oldvalp = new vluint32_t[nextCode()];
-
-    // Set callback so flush/abort will flush this file
-    Verilated::addFlushCb(VerilatedTrace<VL_DERIVED_T>::onFlush, this);
-    Verilated::addExitCb(VerilatedTrace<VL_DERIVED_T>::onExit, this);
-
-#ifdef VL_TRACE_THREADED
-    // Compute trace buffer size. we need to be able to store a new value for
-    // each signal, which is 'nextCode()' entries after the init callbacks
-    // above have been run, plus up to 2 more words of metadata per signal,
-    // plus fixed overhead of 1 for a termination flag and 3 for a time stamp
-    // update.
-    m_traceBufferSize = nextCode() + numSignals() * 2 + 4;
-
-    // Start the worker thread
-    m_workerThread.reset(new std::thread{&VerilatedTrace<VL_DERIVED_T>::workerThreadMain, this});
-#endif
-}
-
-template <>
-void VerilatedTrace<VL_DERIVED_T>::declCode(vluint32_t code, vluint32_t bits, bool tri) {
-    if (VL_UNCOVERABLE(!code)) {
-        VL_FATAL_MT(__FILE__, __LINE__, "", "Internal: internal trace problem, code 0 is illegal");
-    }
-    // Note: The tri-state flag is not used by Verilator, but is here for
-    // compatibility with some foreign code.
-    int codesNeeded = VL_WORDS_I(bits);
-    if (tri) codesNeeded *= 2;
-    m_nextCode = std::max(m_nextCode, code + codesNeeded);
-    ++m_numSignals;
-    m_maxBits = std::max(m_maxBits, bits);
-}
-
-//=========================================================================
-// Internals available to format specific implementations
-
-template <> std::string VerilatedTrace<VL_DERIVED_T>::timeResStr() const {
-    return doubleToTimescale(m_timeRes);
-}
-
-//=========================================================================
-// External interface to client code
-
-template <> void VerilatedTrace<VL_DERIVED_T>::set_time_unit(const char* unitp) VL_MT_SAFE {
-    m_timeUnit = timescaleToDouble(unitp);
-}
-template <> void VerilatedTrace<VL_DERIVED_T>::set_time_unit(const std::string& unit) VL_MT_SAFE {
-    set_time_unit(unit.c_str());
-}
-template <> void VerilatedTrace<VL_DERIVED_T>::set_time_resolution(const char* unitp) VL_MT_SAFE {
-    m_timeRes = timescaleToDouble(unitp);
-}
-template <>
-void VerilatedTrace<VL_DERIVED_T>::set_time_resolution(const std::string& unit) VL_MT_SAFE {
-    set_time_resolution(unit.c_str());
-}
-
-template <>
-void VerilatedTrace<VL_DERIVED_T>::dump(vluint64_t timeui) VL_MT_SAFE_EXCLUDES(m_mutex) {
-    // Not really VL_MT_SAFE but more VL_MT_UNSAFE_ONE.
-    // This does get the mutex, but if multiple threads are trying to dump
-    // chances are the data being dumped will have other problems
-    const VerilatedLockGuard lock{m_mutex};
-    if (VL_UNCOVERABLE(m_timeLastDump && timeui <= m_timeLastDump)) {  // LCOV_EXCL_START
-        VL_PRINTF_MT("%%Warning: previous dump at t=%" PRIu64 ", requesting t=%" PRIu64
-                     ", dump call ignored\n",
-                     m_timeLastDump, timeui);
-        return;
-    }  // LCOV_EXCL_STOP
-    m_timeLastDump = timeui;
-
-    Verilated::quiesce();
-
-    // Call hook for format specific behaviour
-    if (VL_UNLIKELY(m_fullDump)) {
-        if (!preFullDump()) return;
-    } else {
-        if (!preChangeDump()) return;
-    }
-
-#ifdef VL_TRACE_THREADED
-    // Currently only incremental dumps run on the worker thread
-    vluint32_t* bufferp = nullptr;
-    if (VL_LIKELY(!m_fullDump)) {
-        // Get the trace buffer we are about to fill
-        bufferp = getTraceBuffer();
-        m_traceBufferWritep = bufferp;
-        m_traceBufferEndp = bufferp + m_traceBufferSize;
-
-        // Tell worker to update time point
-        m_traceBufferWritep[0] = VerilatedTraceCommand::TIME_CHANGE;
-        *reinterpret_cast<vluint64_t*>(m_traceBufferWritep + 1) = timeui;
-        m_traceBufferWritep += 3;
-    } else {
-        // Update time point
-        flushBase();
-        emitTimeChange(timeui);
-    }
-#else
-    // Update time point
-    emitTimeChange(timeui);
-#endif
-
-    // Run the callbacks
-    if (VL_UNLIKELY(m_fullDump)) {
-        m_fullDump = false;  // No more need for next dump to be full
-        for (vluint32_t i = 0; i < m_fullCbs.size(); ++i) {
-            const CallbackRecord& cbr = m_fullCbs[i];
-            cbr.m_dumpCb(cbr.m_userp, self());
-        }
-    } else {
-        for (vluint32_t i = 0; i < m_chgCbs.size(); ++i) {
-            const CallbackRecord& cbr = m_chgCbs[i];
-            cbr.m_dumpCb(cbr.m_userp, self());
-        }
-    }
-
-    for (vluint32_t i = 0; i < m_cleanupCbs.size(); ++i) {
-        const CallbackRecord& cbr = m_cleanupCbs[i];
-        cbr.m_dumpCb(cbr.m_userp, self());
-    }
-
-#ifdef VL_TRACE_THREADED
-    if (VL_LIKELY(bufferp)) {
-        // Mark end of the trace buffer we just filled
-        *m_traceBufferWritep++ = VerilatedTraceCommand::END;
-
-        // Assert no buffer overflow
-        assert(m_traceBufferWritep - bufferp <= m_traceBufferSize);
-
-        // Pass it to the worker thread
-        m_buffersToWorker.put(bufferp);
-    }
-#endif
-}
-
-//=============================================================================
-// Non-hot path internal interface to Verilator generated code
-
-template <>
-void VerilatedTrace<VL_DERIVED_T>::addCallbackRecord(std::vector<CallbackRecord>& cbVec,
-                                                     CallbackRecord& cbRec)
-    VL_MT_SAFE_EXCLUDES(m_mutex) {
-    const VerilatedLockGuard lock{m_mutex};
-    if (VL_UNCOVERABLE(timeLastDump() != 0)) {  // LCOV_EXCL_START
-        const std::string msg = (std::string{"Internal: "} + __FILE__ + "::" + __FUNCTION__
-                                 + " called with already open file");
-        VL_FATAL_MT(__FILE__, __LINE__, "", msg.c_str());
-    }  // LCOV_EXCL_STOP
-    cbVec.push_back(cbRec);
-}
-
-template <> void VerilatedTrace<VL_DERIVED_T>::addInitCb(initCb_t cb, void* userp) VL_MT_SAFE {
-    CallbackRecord cbr{cb, userp};
-    addCallbackRecord(m_initCbs, cbr);
-}
-template <> void VerilatedTrace<VL_DERIVED_T>::addFullCb(dumpCb_t cb, void* userp) VL_MT_SAFE {
-    CallbackRecord cbr{cb, userp};
-    addCallbackRecord(m_fullCbs, cbr);
-}
-template <> void VerilatedTrace<VL_DERIVED_T>::addChgCb(dumpCb_t cb, void* userp) VL_MT_SAFE {
-    CallbackRecord cbr{cb, userp};
-    addCallbackRecord(m_chgCbs, cbr);
-}
-template <> void VerilatedTrace<VL_DERIVED_T>::addCleanupCb(dumpCb_t cb, void* userp) VL_MT_SAFE {
-    CallbackRecord cbr{cb, userp};
-    addCallbackRecord(m_cleanupCbs, cbr);
-}
-
-template <> void VerilatedTrace<VL_DERIVED_T>::pushNamePrefix(const std::string& prefix) {
-    m_namePrefixStack.push_back(m_namePrefixStack.back() + prefix);
-}
-
-template <> void VerilatedTrace<VL_DERIVED_T>::popNamePrefix(unsigned count) {
-    while (count--) m_namePrefixStack.pop_back();
-    assert(!m_namePrefixStack.empty());
-}
-
-//=========================================================================
-// Hot path internal interface to Verilator generated code
-
-// These functions must write the new value back into the old value store,
-// and subsequently call the format specific emit* implementations. Note
-// that this file must be included in the format specific implementation, so
-// the emit* functions can be inlined for performance.
-
-template <> void VerilatedTrace<VL_DERIVED_T>::fullBit(vluint32_t* oldp, CData newval) {
-    *oldp = newval;
-    self()->emitBit(oldp - m_sigs_oldvalp, newval);
-}
-
-template <>
-void VerilatedTrace<VL_DERIVED_T>::fullCData(vluint32_t* oldp, CData newval, int bits) {
-    *oldp = newval;
-    self()->emitCData(oldp - m_sigs_oldvalp, newval, bits);
-}
-
-template <>
-void VerilatedTrace<VL_DERIVED_T>::fullSData(vluint32_t* oldp, SData newval, int bits) {
-    *oldp = newval;
-    self()->emitSData(oldp - m_sigs_oldvalp, newval, bits);
-}
-
-template <>
-void VerilatedTrace<VL_DERIVED_T>::fullIData(vluint32_t* oldp, IData newval, int bits) {
-    *oldp = newval;
-    self()->emitIData(oldp - m_sigs_oldvalp, newval, bits);
-}
-
-template <>
-void VerilatedTrace<VL_DERIVED_T>::fullQData(vluint32_t* oldp, QData newval, int bits) {
-    *reinterpret_cast<QData*>(oldp) = newval;
-    self()->emitQData(oldp - m_sigs_oldvalp, newval, bits);
-}
-
-template <>
-void VerilatedTrace<VL_DERIVED_T>::fullWData(vluint32_t* oldp, const WData* newvalp, int bits) {
-    for (int i = 0; i < VL_WORDS_I(bits); ++i) oldp[i] = newvalp[i];
-    self()->emitWData(oldp - m_sigs_oldvalp, newvalp, bits);
-}
-
-template <> void VerilatedTrace<VL_DERIVED_T>::fullDouble(vluint32_t* oldp, double newval) {
-    // cppcheck-suppress invalidPointerCast
-    *reinterpret_cast<double*>(oldp) = newval;
-    self()->emitDouble(oldp - m_sigs_oldvalp, newval);
-}
-
-//=========================================================================
-// Primitives converting binary values to strings...
-
-// All of these take a destination pointer where the string will be emitted,
-// and a value to convert. There are a couple of variants for efficiency.
-
-static inline void cvtCDataToStr(char* dstp, CData value) {
-#ifdef VL_HAVE_SSE2
-    // Similar to cvtSDataToStr but only the bottom 8 byte lanes are used
-    const __m128i a = _mm_cvtsi32_si128(value);
-    const __m128i b = _mm_unpacklo_epi8(a, a);
-    const __m128i c = _mm_shufflelo_epi16(b, 0);
-    const __m128i m = _mm_set1_epi64x(0x0102040810204080);
-    const __m128i d = _mm_cmpeq_epi8(_mm_and_si128(c, m), m);
-    const __m128i result = _mm_sub_epi8(_mm_set1_epi8('0'), d);
-    _mm_storel_epi64(reinterpret_cast<__m128i*>(dstp), result);
-#else
-    dstp[0] = '0' | static_cast<char>((value >> 7) & 1);
-    dstp[1] = '0' | static_cast<char>((value >> 6) & 1);
-    dstp[2] = '0' | static_cast<char>((value >> 5) & 1);
-    dstp[3] = '0' | static_cast<char>((value >> 4) & 1);
-    dstp[4] = '0' | static_cast<char>((value >> 3) & 1);
-    dstp[5] = '0' | static_cast<char>((value >> 2) & 1);
-    dstp[6] = '0' | static_cast<char>((value >> 1) & 1);
-    dstp[7] = '0' | static_cast<char>(value & 1);
-#endif
-}
-
-static inline void cvtSDataToStr(char* dstp, SData value) {
-#ifdef VL_HAVE_SSE2
-    // We want each bit in the 16-bit input value to end up in a byte lane
-    // within the 128-bit XMM register. Note that x86 is little-endian and we
-    // want the MSB of the input at the low address, so we will bit-reverse
-    // at the same time.
-
-    // Put value in bottom of 128-bit register a[15:0] = value
-    const __m128i a = _mm_cvtsi32_si128(value);
-    // Interleave bytes with themselves
-    // b[15: 0] = {2{a[ 7:0]}} == {2{value[ 7:0]}}
-    // b[31:16] = {2{a[15:8]}} == {2{value[15:8]}}
-    const __m128i b = _mm_unpacklo_epi8(a, a);
-    // Shuffle bottom 64 bits, note swapping high bytes with low bytes
-    // c[31: 0] = {2{b[31:16]}} == {4{value[15:8}}
-    // c[63:32] = {2{b[15: 0]}} == {4{value[ 7:0}}
-    const __m128i c = _mm_shufflelo_epi16(b, 0x05);
-    // Shuffle whole register
-    // d[ 63: 0] = {2{c[31: 0]}} == {8{value[15:8}}
-    // d[126:54] = {2{c[63:32]}} == {8{value[ 7:0}}
-    const __m128i d = _mm_shuffle_epi32(c, 0x50);
-    // Test each bit within the bytes, this sets each byte lane to 0
-    // if the bit for that lane is 0 and to 0xff if the bit is 1.
-    const __m128i m = _mm_set1_epi64x(0x0102040810204080);
-    const __m128i e = _mm_cmpeq_epi8(_mm_and_si128(d, m), m);
-    // Convert to ASCII by subtracting the masks from ASCII '0':
-    // '0' - 0 is '0', '0' - -1 is '1'
-    const __m128i result = _mm_sub_epi8(_mm_set1_epi8('0'), e);
-    // Store the 16 characters to the un-aligned buffer
-    _mm_storeu_si128(reinterpret_cast<__m128i*>(dstp), result);
-#else
-    cvtCDataToStr(dstp, value >> 8);
-    cvtCDataToStr(dstp + 8, value);
-#endif
-}
-
-static inline void cvtIDataToStr(char* dstp, IData value) {
-#ifdef VL_HAVE_AVX2
-    // Similar to cvtSDataToStr but the bottom 16-bits are processed in the
-    // top half of the YMM registerss
-    const __m256i a = _mm256_insert_epi32(_mm256_undefined_si256(), value, 0);
-    const __m256i b = _mm256_permute4x64_epi64(a, 0);
-    const __m256i s = _mm256_set_epi8(0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2,
-                                      2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3);
-    const __m256i c = _mm256_shuffle_epi8(b, s);
-    const __m256i m = _mm256_set1_epi64x(0x0102040810204080);
-    const __m256i d = _mm256_cmpeq_epi8(_mm256_and_si256(c, m), m);
-    const __m256i result = _mm256_sub_epi8(_mm256_set1_epi8('0'), d);
-    _mm256_storeu_si256(reinterpret_cast<__m256i*>(dstp), result);
-#else
-    cvtSDataToStr(dstp, value >> 16);
-    cvtSDataToStr(dstp + 16, value);
-#endif
-}
-
-static inline void cvtQDataToStr(char* dstp, QData value) {
-    cvtIDataToStr(dstp, value >> 32);
-    cvtIDataToStr(dstp + 32, value);
-}
-
-#define cvtEDataToStr cvtIDataToStr
-
-//=============================================================================
-
-#ifdef VERILATED_VCD_TEST
-
-void verilated_trace_imp_selftest() {
-#define SELF_CHECK(got, exp) \
-    do { \
-        if ((got) != (exp)) VL_FATAL_MT(__FILE__, __LINE__, "", "%Error: selftest"); \
-    } while (0)
-
-#define SELF_CHECK_TS(scale) \
-    SELF_CHECK(doubleToTimescale(timescaleToDouble(scale)), std::string{scale});
-    SELF_CHECK_TS("100s");
-    SELF_CHECK_TS("10s");
-    SELF_CHECK_TS("1s");
-    SELF_CHECK_TS("100ms");
-    SELF_CHECK_TS("10ms");
-    SELF_CHECK_TS("1ms");
-    SELF_CHECK_TS("100us");
-    SELF_CHECK_TS("10us");
-    SELF_CHECK_TS("1us");
-    SELF_CHECK_TS("100ns");
-    SELF_CHECK_TS("10ns");
-    SELF_CHECK_TS("1ns");
-    SELF_CHECK_TS("100ps");
-    SELF_CHECK_TS("10ps");
-    SELF_CHECK_TS("1ps");
-    SELF_CHECK_TS("100fs");
-    SELF_CHECK_TS("10fs");
-    SELF_CHECK_TS("1fs");
-    SELF_CHECK_TS("100as");
-    SELF_CHECK_TS("10as");
-    SELF_CHECK_TS("1as");
-}
-
-#endif
-
-#endif  // VL_CPPCHECK
@@ -0,0 +1,935 @@
+// -*- mode: C++; c-file-style: "cc-mode" -*-
+//=============================================================================
+//
+// Code available from: https://verilator.org
+//
+// Copyright 2001-2022 by Wilson Snyder. This program is free software; you
+// can redistribute it and/or modify it under the terms of either the GNU
+// Lesser General Public License Version 3 or the Perl Artistic License
+// Version 2.0.
+// SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
+//
+//=============================================================================
+//
+// Verilated tracing implementation code template common to all formats.
+// This file is included by the format specific implementations and
+// should not be used otherwise.
+//
+//=============================================================================
+
+// clang-format off
+
+#ifndef VL_CPPCHECK
+#if !defined(VL_SUB_T) || !defined(VL_BUF_T)
+# error "This file should be included in trace format implementations"
+#endif
+
+#include "verilated_intrinsics.h"
+#include "verilated_trace.h"
+#ifdef VL_THREADED
+# include "verilated_threads.h"
+# include <list>
+#endif
+
+#if 0
+# include <iostream>
+# define VL_TRACE_OFFLOAD_DEBUG(msg) std::cout << "TRACE OFFLOAD THREAD: " << msg << std::endl
+#else
+# define VL_TRACE_OFFLOAD_DEBUG(msg)
+#endif
+
+// clang-format on
+
+//=============================================================================
+// Static utility functions
+
+static double timescaleToDouble(const char* unitp) {
+    char* endp = nullptr;
+    double value = std::strtod(unitp, &endp);
+    // On error so we allow just "ns" to return 1e-9.
+    if (value == 0.0 && endp == unitp) value = 1;
+    unitp = endp;
+    for (; *unitp && std::isspace(*unitp); unitp++) {}
+    switch (*unitp) {
+    case 's': value *= 1e0; break;
+    case 'm': value *= 1e-3; break;
+    case 'u': value *= 1e-6; break;
+    case 'n': value *= 1e-9; break;
+    case 'p': value *= 1e-12; break;
+    case 'f': value *= 1e-15; break;
+    case 'a': value *= 1e-18; break;
+    }
+    return value;
+}
+
+static std::string doubleToTimescale(double value) {
+    const char* suffixp = "s";
+    // clang-format off
+    if      (value >= 1e0)   { suffixp = "s"; value *= 1e0; }
+    else if (value >= 1e-3 ) { suffixp = "ms"; value *= 1e3; }
+    else if (value >= 1e-6 ) { suffixp = "us"; value *= 1e6; }
+    else if (value >= 1e-9 ) { suffixp = "ns"; value *= 1e9; }
+    else if (value >= 1e-12) { suffixp = "ps"; value *= 1e12; }
+    else if (value >= 1e-15) { suffixp = "fs"; value *= 1e15; }
+    else if (value >= 1e-18) { suffixp = "as"; value *= 1e18; }
+    // clang-format on
+    char valuestr[100];
+    VL_SNPRINTF(valuestr, 100, "%0.0f%s", value, suffixp);
+    return valuestr;  // Gets converted to string, so no ref to stack
+}
+
+#ifdef VL_THREADED
+//=========================================================================
+// Buffer management
+
+template <>
+uint32_t* VerilatedTrace<VL_SUB_T, VL_BUF_T>::getOffloadBuffer() {
+    uint32_t* bufferp;
+    // Some jitter is expected, so some number of alternative offlaod buffers are
+    // required, but don't allocate more than 8 buffers.
+    if (m_numOffloadBuffers < 8) {
+        // Allocate a new buffer if none is available
+        if (!m_offloadBuffersFromWorker.tryGet(bufferp)) {
+            ++m_numOffloadBuffers;
+            // Note: over allocate a bit so pointer comparison is well defined
+            // if we overflow only by a small amount
+            bufferp = new uint32_t[m_offloadBufferSize + 16];
+        }
+    } else {
+        // Block until a buffer becomes available
+        bufferp = m_offloadBuffersFromWorker.get();
+    }
+    return bufferp;
+}
+
+template <>
+void VerilatedTrace<VL_SUB_T, VL_BUF_T>::waitForOffloadBuffer(const uint32_t* buffp) {
+    // Slow path code only called on flush/shutdown, so use a simple algorithm.
+    // Collect buffers from worker and stash them until we get the one we want.
+    std::deque<uint32_t*> stash;
+    do { stash.push_back(m_offloadBuffersFromWorker.get()); } while (stash.back() != buffp);
+    // Now put them back in the queue, in the original order.
+    while (!stash.empty()) {
+        m_offloadBuffersFromWorker.put_front(stash.back());
+        stash.pop_back();
+    }
+}
+
+//=========================================================================
+// Worker thread
+
+template <>
+void VerilatedTrace<VL_SUB_T, VL_BUF_T>::offloadWorkerThreadMain() {
+    bool shutdown = false;
+
+    do {
+        uint32_t* const bufferp = m_offloadBuffersToWorker.get();
+
+        VL_TRACE_OFFLOAD_DEBUG("");
+        VL_TRACE_OFFLOAD_DEBUG("Got buffer: " << bufferp);
+
+        const uint32_t* readp = bufferp;
+
+        std::unique_ptr<Buffer> traceBufp;  // We own the passed tracebuffer
+
+        while (true) {
+            const uint32_t cmd = readp[0];
+            const uint32_t top = cmd >> 4;
+            // Always set this up, as it is almost always needed
+            uint32_t* const oldp = m_sigs_oldvalp + readp[1];
+            // Note this increment needs to be undone on commands which do not
+            // actually contain a code, but those are the rare cases.
+            readp += 2;
+
+            switch (cmd & 0xF) {
+                //===
+                // CHG_* commands
+            case VerilatedTraceOffloadCommand::CHG_BIT_0:
+                VL_TRACE_OFFLOAD_DEBUG("Command CHG_BIT_0 " << top);
+                traceBufp->chgBit(oldp, 0);
+                continue;
+            case VerilatedTraceOffloadCommand::CHG_BIT_1:
+                VL_TRACE_OFFLOAD_DEBUG("Command CHG_BIT_1 " << top);
+                traceBufp->chgBit(oldp, 1);
+                continue;
+            case VerilatedTraceOffloadCommand::CHG_CDATA:
+                VL_TRACE_OFFLOAD_DEBUG("Command CHG_CDATA " << top);
+                // Bits stored in bottom byte of command
+                traceBufp->chgCData(oldp, *readp, top);
+                readp += 1;
+                continue;
+            case VerilatedTraceOffloadCommand::CHG_SDATA:
+                VL_TRACE_OFFLOAD_DEBUG("Command CHG_SDATA " << top);
+                // Bits stored in bottom byte of command
+                traceBufp->chgSData(oldp, *readp, top);
+                readp += 1;
+                continue;
+            case VerilatedTraceOffloadCommand::CHG_IDATA:
+                VL_TRACE_OFFLOAD_DEBUG("Command CHG_IDATA " << top);
+                // Bits stored in bottom byte of command
+                traceBufp->chgIData(oldp, *readp, top);
+                readp += 1;
+                continue;
+            case VerilatedTraceOffloadCommand::CHG_QDATA:
+                VL_TRACE_OFFLOAD_DEBUG("Command CHG_QDATA " << top);
+                // Bits stored in bottom byte of command
+                traceBufp->chgQData(oldp, *reinterpret_cast<const QData*>(readp), top);
+                readp += 2;
+                continue;
+            case VerilatedTraceOffloadCommand::CHG_WDATA:
+                VL_TRACE_OFFLOAD_DEBUG("Command CHG_WDATA " << top);
+                traceBufp->chgWData(oldp, readp, top);
+                readp += VL_WORDS_I(top);
+                continue;
+            case VerilatedTraceOffloadCommand::CHG_DOUBLE:
+                VL_TRACE_OFFLOAD_DEBUG("Command CHG_DOUBLE " << top);
+                traceBufp->chgDouble(oldp, *reinterpret_cast<const double*>(readp));
+                readp += 2;
+                continue;
+
+                //===
+                // Rare commands
+            case VerilatedTraceOffloadCommand::TIME_CHANGE:
+                VL_TRACE_OFFLOAD_DEBUG("Command TIME_CHANGE " << top);
+                readp -= 1;  // No code in this command, undo increment
+                emitTimeChange(*reinterpret_cast<const uint64_t*>(readp));
+                readp += 2;
+                continue;
+
+            case VerilatedTraceOffloadCommand::TRACE_BUFFER:
+                VL_TRACE_OFFLOAD_DEBUG("Command TRACE_BUFFER " << top);
+                readp -= 1;  // No code in this command, undo increment
+                traceBufp.reset(*reinterpret_cast<Buffer* const*>(readp));
+                readp += 2;
+                continue;
+
+                //===
+                // Commands ending this buffer
+            case VerilatedTraceOffloadCommand::END:  //
+                VL_TRACE_OFFLOAD_DEBUG("Command END");
+                break;
+            case VerilatedTraceOffloadCommand::SHUTDOWN:
+                VL_TRACE_OFFLOAD_DEBUG("Command SHUTDOWN");
+                shutdown = true;
+                break;
+
+            //===
+            // Unknown command
+            default: {  // LCOV_EXCL_START
+                VL_TRACE_OFFLOAD_DEBUG("Command UNKNOWN " << cmd);
+                VL_FATAL_MT(__FILE__, __LINE__, "", "Unknown trace command");
+                break;
+            }  // LCOV_EXCL_STOP
+            }
+
+            // The above switch will execute 'continue' when necessary,
+            // so if we ever reach here, we are done with the buffer.
+            break;
+        }
+
+        VL_TRACE_OFFLOAD_DEBUG("Returning buffer");
+
+        // Return buffer
+        m_offloadBuffersFromWorker.put(bufferp);
+    } while (VL_LIKELY(!shutdown));
+}
+
+template <>
+void VerilatedTrace<VL_SUB_T, VL_BUF_T>::shutdownOffloadWorker() {
+    // If the worker thread is not running, done..
+    if (!m_workerThread) return;
+
+    // Hand an buffer with a shutdown command to the worker thread
+    uint32_t* const bufferp = getOffloadBuffer();
+    bufferp[0] = VerilatedTraceOffloadCommand::SHUTDOWN;
+    m_offloadBuffersToWorker.put(bufferp);
+    // Wait for it to return
+    waitForOffloadBuffer(bufferp);
+    // Join the thread and delete it
+    m_workerThread->join();
+    m_workerThread.reset(nullptr);
+}
+
+#endif
+
+//=============================================================================
+// Life cycle
+
+template <>
+void VerilatedTrace<VL_SUB_T, VL_BUF_T>::closeBase() {
+#ifdef VL_THREADED
+    if (offload()) {
+        shutdownOffloadWorker();
+        while (m_numOffloadBuffers) {
+            delete[] m_offloadBuffersFromWorker.get();
+            --m_numOffloadBuffers;
+        }
+    }
+#endif
+}
+
+template <>
+void VerilatedTrace<VL_SUB_T, VL_BUF_T>::flushBase() {
+#ifdef VL_THREADED
+    if (offload()) {
+        // Hand an empty buffer to the worker thread
+        uint32_t* const bufferp = getOffloadBuffer();
+        *bufferp = VerilatedTraceOffloadCommand::END;
+        m_offloadBuffersToWorker.put(bufferp);
+        // Wait for it to be returned. As the processing is in-order,
+        // this ensures all previous buffers have been processed.
+        waitForOffloadBuffer(bufferp);
+    }
+#endif
+}
+
+//=============================================================================
+// Callbacks to run on global events
+
+template <>
+void VerilatedTrace<VL_SUB_T, VL_BUF_T>::onFlush(void* selfp) {
+    // This calls 'flush' on the derived class (which must then get any mutex)
+    reinterpret_cast<VL_SUB_T*>(selfp)->flush();
+}
+
+template <>
+void VerilatedTrace<VL_SUB_T, VL_BUF_T>::onExit(void* selfp) {
+    // This calls 'close' on the derived class (which must then get any mutex)
+    reinterpret_cast<VL_SUB_T*>(selfp)->close();
+}
+
+//=============================================================================
+// VerilatedTrace
+
+template <>
+VerilatedTrace<VL_SUB_T, VL_BUF_T>::VerilatedTrace() {
+    set_time_unit(Verilated::threadContextp()->timeunitString());
+    set_time_resolution(Verilated::threadContextp()->timeprecisionString());
+}
+
+template <>
+VerilatedTrace<VL_SUB_T, VL_BUF_T>::~VerilatedTrace() {
+    if (m_sigs_oldvalp) VL_DO_CLEAR(delete[] m_sigs_oldvalp, m_sigs_oldvalp = nullptr);
+    if (m_sigs_enabledp) VL_DO_CLEAR(delete[] m_sigs_enabledp, m_sigs_enabledp = nullptr);
+    Verilated::removeFlushCb(VerilatedTrace<VL_SUB_T, VL_BUF_T>::onFlush, this);
+    Verilated::removeExitCb(VerilatedTrace<VL_SUB_T, VL_BUF_T>::onExit, this);
+    if (offload()) closeBase();
+}
+
+//=========================================================================
+// Internals available to format specific implementations
+
+template <>
+void VerilatedTrace<VL_SUB_T, VL_BUF_T>::traceInit() VL_MT_UNSAFE {
+    // Note: It is possible to re-open a trace file (VCD in particular),
+    // so we must reset the next code here, but it must have the same number
+    // of codes on re-open
+    const uint32_t expectedCodes = nextCode();
+    m_nextCode = 1;
+    m_numSignals = 0;
+    m_maxBits = 0;
+    m_sigs_enabledVec.clear();
+
+    // Call all initialize callbacks, which will:
+    // - Call decl* for each signal (these eventually call ::declCode)
+    // - Store the base code
+    for (uint32_t i = 0; i < m_initCbs.size(); ++i) {
+        const CallbackRecord& cbr = m_initCbs[i];
+        cbr.m_initCb(cbr.m_userp, self(), nextCode());
+    }
+
+    if (expectedCodes && nextCode() != expectedCodes) {
+        VL_FATAL_MT(__FILE__, __LINE__, "",
+                    "Reopening trace file with different number of signals");
+    }
+
+    // Now that we know the number of codes, allocate space for the buffer
+    // holding previous signal values.
+    if (!m_sigs_oldvalp) m_sigs_oldvalp = new uint32_t[nextCode()];
+
+    // Apply enables
+    if (m_sigs_enabledp) VL_DO_CLEAR(delete[] m_sigs_enabledp, m_sigs_enabledp = nullptr);
+    if (!m_sigs_enabledVec.empty()) {
+        // Else if was empty, m_sigs_enabledp = nullptr to short circuit tests
+        // But it isn't, so alloc one bit for each code to indicate enablement
+        // We don't want to still use m_signs_enabledVec as std::vector<bool> is not
+        // guarenteed to be fast
+        m_sigs_enabledp = new uint32_t[1 + VL_WORDS_I(nextCode())]{0};
+        m_sigs_enabledVec.reserve(nextCode());
+        for (size_t code = 0; code < nextCode(); ++code) {
+            if (m_sigs_enabledVec[code]) {
+                m_sigs_enabledp[VL_BITWORD_I(code)] |= 1U << VL_BITBIT_I(code);
+            }
+        }
+        m_sigs_enabledVec.clear();
+    }
+
+    // Set callback so flush/abort will flush this file
+    Verilated::addFlushCb(VerilatedTrace<VL_SUB_T, VL_BUF_T>::onFlush, this);
+    Verilated::addExitCb(VerilatedTrace<VL_SUB_T, VL_BUF_T>::onExit, this);
+
+#ifdef VL_THREADED
+    if (offload()) {
+        // Compute offload buffer size. we need to be able to store a new value for
+        // each signal, which is 'nextCode()' entries after the init callbacks
+        // above have been run, plus up to 2 more words of metadata per signal,
+        // plus fixed overhead of 1 for a termination flag and 3 for a time stamp
+        // update.
+        m_offloadBufferSize = nextCode() + numSignals() * 2 + 4;
+
+        // Start the worker thread
+        m_workerThread.reset(
+            new std::thread{&VerilatedTrace<VL_SUB_T, VL_BUF_T>::offloadWorkerThreadMain, this});
+    }
+#endif
+}
+
+template <>
+bool VerilatedTrace<VL_SUB_T, VL_BUF_T>::declCode(uint32_t code, const char* namep, uint32_t bits,
+                                                  bool tri) {
+    if (VL_UNCOVERABLE(!code)) {
+        VL_FATAL_MT(__FILE__, __LINE__, "", "Internal: internal trace problem, code 0 is illegal");
+    }
+    // To keep it simple, this is O(enables * signals), but we expect few enables
+    std::string declName = namePrefix() + namep;
+    bool enabled = false;
+    if (m_dumpvars.empty()) enabled = true;
+    for (const auto& item : m_dumpvars) {
+        const int dumpvarsLevel = item.first;
+        const char* dvp = item.second.c_str();
+        const char* np = declName.c_str();
+        while (*dvp && *dvp == *np) {
+            ++dvp;
+            ++np;
+        }
+        if (*dvp) continue;  // Didn't match dumpvar item
+        if (*np && *np != ' ') continue;  // e.g. "t" isn't a match for "top"
+        int levels = 0;
+        while (*np) {
+            if (*np++ == ' ') ++levels;
+        }
+        if (levels > dumpvarsLevel) continue;  // Too deep
+        // We only need to set first code word if it's a multicode signal
+        // as that's all we'll check for later
+        if (m_sigs_enabledVec.size() <= code) m_sigs_enabledVec.resize((code + 1024) * 2);
+        m_sigs_enabledVec[code] = true;
+        enabled = true;
+        break;
+    }
+
+    // Note: The tri-state flag is not used by Verilator, but is here for
+    // compatibility with some foreign code.
+    int codesNeeded = VL_WORDS_I(bits);
+    if (tri) codesNeeded *= 2;
+    m_nextCode = std::max(m_nextCode, code + codesNeeded);
+    ++m_numSignals;
+    m_maxBits = std::max(m_maxBits, bits);
+    return enabled;
+}
+
+//=========================================================================
+// Internals available to format specific implementations
+
+template <>
+std::string VerilatedTrace<VL_SUB_T, VL_BUF_T>::timeResStr() const {
+    return doubleToTimescale(m_timeRes);
+}
+
+//=========================================================================
+// External interface to client code
+
+template <>
+void VerilatedTrace<VL_SUB_T, VL_BUF_T>::set_time_unit(const char* unitp) VL_MT_SAFE {
+    m_timeUnit = timescaleToDouble(unitp);
+}
+template <>
+void VerilatedTrace<VL_SUB_T, VL_BUF_T>::set_time_unit(const std::string& unit) VL_MT_SAFE {
+    set_time_unit(unit.c_str());
+}
+template <>
+void VerilatedTrace<VL_SUB_T, VL_BUF_T>::set_time_resolution(const char* unitp) VL_MT_SAFE {
+    m_timeRes = timescaleToDouble(unitp);
+}
+template <>
+void VerilatedTrace<VL_SUB_T, VL_BUF_T>::set_time_resolution(const std::string& unit) VL_MT_SAFE {
+    set_time_resolution(unit.c_str());
+}
+template <>
+void VerilatedTrace<VL_SUB_T, VL_BUF_T>::dumpvars(int level, const std::string& hier) VL_MT_SAFE {
+    if (level == 0) {
+        m_dumpvars.clear();  // empty = everything on
+    } else {
+        // Convert Verilog . separators to trace space separators
+        std::string hierSpaced = hier;
+        for (auto& i : hierSpaced) {
+            if (i == '.') i = ' ';
+        }
+        m_dumpvars.push_back(std::make_pair(level, hierSpaced));
+    }
+}
+
+#ifdef VL_THREADED
+template <>
+void VerilatedTrace<VL_SUB_T, VL_BUF_T>::parallelWorkerTask(void* datap, bool) {
+    ParallelWorkerData* const wdp = reinterpret_cast<ParallelWorkerData*>(datap);
+    // Run the task
+    wdp->m_cb(wdp->m_userp, wdp->m_bufp);
+    // Mark buffer as ready
+    const VerilatedLockGuard lock{wdp->m_mutex};
+    wdp->m_ready.store(true);
+    if (wdp->m_waiting) wdp->m_cv.notify_one();
+}
+
+template <>
+VL_ATTR_NOINLINE void VerilatedTrace<VL_SUB_T, VL_BUF_T>::ParallelWorkerData::wait() {
+    // Spin for a while, waiting for the buffer to become ready
+    for (int i = 0; i < VL_LOCK_SPINS; ++i) {
+        if (VL_LIKELY(m_ready.load(std::memory_order_relaxed))) return;
+        VL_CPU_RELAX();
+    }
+    // We have been spinning for a while, so yield the thread
+    VerilatedLockGuard lock{m_mutex};
+    m_waiting = true;
+    m_cv.wait(lock, [this] { return m_ready.load(std::memory_order_relaxed); });
+    m_waiting = false;
+}
+#endif
+
+template <>
+void VerilatedTrace<VL_SUB_T, VL_BUF_T>::runCallbacks(const std::vector<CallbackRecord>& cbVec) {
+#ifdef VL_THREADED
+    if (parallel()) {
+        // If tracing in parallel, dispatch to the thread pool
+        VlThreadPool* threadPoolp = static_cast<VlThreadPool*>(m_contextp->threadPoolp());
+        // List of work items for thread (std::list, as ParallelWorkerData is not movable)
+        std::list<ParallelWorkerData> workerData;
+        // We use the whole pool + the main thread
+        const unsigned threads = threadPoolp->numThreads() + 1;
+        // Main thread executes all jobs with index % threads == 0
+        std::vector<ParallelWorkerData*> mainThreadWorkerData;
+        // Enuque all the jobs
+        for (unsigned i = 0; i < cbVec.size(); ++i) {
+            const CallbackRecord& cbr = cbVec[i];
+            // Always get the trace buffer on the main thread
+            Buffer* const bufp = getTraceBuffer();
+            // Create new work item
+            workerData.emplace_back(cbr.m_dumpCb, cbr.m_userp, bufp);
+            // Grab the new work item
+            ParallelWorkerData* const itemp = &workerData.back();
+            // Enqueue task to thread pool, or main thread
+            if (unsigned rem = i % threads) {
+                threadPoolp->workerp(rem - 1)->addTask(parallelWorkerTask, itemp);
+            } else {
+                mainThreadWorkerData.push_back(itemp);
+            }
+        }
+        // Execute main thead jobs
+        for (ParallelWorkerData* const itemp : mainThreadWorkerData) {
+            parallelWorkerTask(itemp, false);
+        }
+        // Commit all trace buffers in order
+        for (ParallelWorkerData& item : workerData) {
+            // Wait until ready
+            item.wait();
+            // Commit the buffer
+            commitTraceBuffer(item.m_bufp);
+        }
+
+        // Done
+        return;
+    }
+#endif
+    // Fall back on sequential execution
+    for (const CallbackRecord& cbr : cbVec) {
+        Buffer* const traceBufferp = getTraceBuffer();
+        cbr.m_dumpCb(cbr.m_userp, traceBufferp);
+        commitTraceBuffer(traceBufferp);
+    }
+}
+
+template <>
+void VerilatedTrace<VL_SUB_T, VL_BUF_T>::runOffloadedCallbacks(
+    const std::vector<CallbackRecord>& cbVec) {
+    // Fall back on sequential execution
+#ifdef VL_THREADED
+    for (const CallbackRecord& cbr : cbVec) {
+        Buffer* traceBufferp = getTraceBuffer();
+        cbr.m_dumpOffloadCb(cbr.m_userp, static_cast<OffloadBuffer*>(traceBufferp));
+        commitTraceBuffer(traceBufferp);
+    }
+#else
+    if (!cbVec.empty()) VL_FATAL_MT(__FILE__, __LINE__, "", "Unreachable");
+#endif
+}
+
+template <>
+void VerilatedTrace<VL_SUB_T, VL_BUF_T>::dump(uint64_t timeui) VL_MT_SAFE_EXCLUDES(m_mutex) {
+    // Not really VL_MT_SAFE but more VL_MT_UNSAFE_ONE.
+    // This does get the mutex, but if multiple threads are trying to dump
+    // chances are the data being dumped will have other problems
+    const VerilatedLockGuard lock{m_mutex};
+    if (VL_UNCOVERABLE(m_didSomeDump && timeui <= m_timeLastDump)) {  // LCOV_EXCL_START
+        VL_PRINTF_MT("%%Warning: previous dump at t=%" PRIu64 ", requesting t=%" PRIu64
+                     ", dump call ignored\n",
+                     m_timeLastDump, timeui);
+        return;
+    }  // LCOV_EXCL_STOP
+    m_timeLastDump = timeui;
+    m_didSomeDump = true;
+
+    Verilated::quiesce();
+
+    // Call hook for format specific behaviour
+    if (VL_UNLIKELY(m_fullDump)) {
+        if (!preFullDump()) return;
+    } else {
+        if (!preChangeDump()) return;
+    }
+
+#ifdef VL_THREADED
+    uint32_t* bufferp = nullptr;
+#endif
+    if (offload()) {
+#ifdef VL_THREADED
+        // Currently only incremental dumps run on the worker thread
+        if (VL_LIKELY(!m_fullDump)) {
+            // Get the offload buffer we are about to fill
+            bufferp = getOffloadBuffer();
+            m_offloadBufferWritep = bufferp;
+            m_offloadBufferEndp = bufferp + m_offloadBufferSize;
+
+            // Tell worker to update time point
+            m_offloadBufferWritep[0] = VerilatedTraceOffloadCommand::TIME_CHANGE;
+            *reinterpret_cast<uint64_t*>(m_offloadBufferWritep + 1) = timeui;
+            m_offloadBufferWritep += 3;
+        } else {
+            // Update time point
+            flushBase();
+            emitTimeChange(timeui);
+        }
+#else
+        VL_FATAL_MT(__FILE__, __LINE__, "", "Unreachable");
+#endif
+    } else {
+        // Update time point
+        emitTimeChange(timeui);
+    }
+
+    // Run the callbacks
+    if (VL_UNLIKELY(m_fullDump)) {
+        m_fullDump = false;  // No more need for next dump to be full
+        if (offload()) {
+            runOffloadedCallbacks(m_fullOffloadCbs);
+        } else {
+            runCallbacks(m_fullCbs);
+        }
+    } else {
+        if (offload()) {
+            runOffloadedCallbacks(m_chgOffloadCbs);
+        } else {
+            runCallbacks(m_chgCbs);
+        }
+    }
+
+    for (uint32_t i = 0; i < m_cleanupCbs.size(); ++i) {
+        const CallbackRecord& cbr = m_cleanupCbs[i];
+        cbr.m_cleanupCb(cbr.m_userp, self());
+    }
+
+#ifdef VL_THREADED
+    if (offload() && VL_LIKELY(bufferp)) {
+        // Mark end of the offload buffer we just filled
+        *m_offloadBufferWritep++ = VerilatedTraceOffloadCommand::END;
+
+        // Assert no buffer overflow
+        assert(m_offloadBufferWritep - bufferp <= m_offloadBufferSize);
+
+        // Pass it to the worker thread
+        m_offloadBuffersToWorker.put(bufferp);
+    }
+#endif
+}
+
+//=============================================================================
+// Non-hot path internal interface to Verilator generated code
+
+template <>
+void VerilatedTrace<VL_SUB_T, VL_BUF_T>::addModel(VerilatedModel* modelp)
+    VL_MT_SAFE_EXCLUDES(m_mutex) {
+    const VerilatedLockGuard lock{m_mutex};
+
+    const bool firstModel = m_models.empty();
+    const bool newModel = m_models.insert(modelp).second;
+    VerilatedContext* const contextp = modelp->contextp();
+
+    // Validate
+    if (!newModel) {  // LCOV_EXCL_START
+        VL_FATAL_MT(__FILE__, __LINE__, "",
+                    "The same model has already been added to this trace file");
+    }
+    if (VL_UNCOVERABLE(m_contextp && contextp != m_contextp)) {
+        VL_FATAL_MT(__FILE__, __LINE__, "",
+                    "A trace file instance can only handle models from the same context");
+    }
+    if (VL_UNCOVERABLE(m_didSomeDump)) {
+        VL_FATAL_MT(__FILE__, __LINE__, "",
+                    "Cannot add models to a trace file if 'dump' has already been called");
+    }  // LCOV_EXCL_STOP
+
+    // Keep hold of the context
+    m_contextp = contextp;
+
+    // Get the desired trace config from the model
+    const std::unique_ptr<VerilatedTraceConfig> configp = modelp->traceConfig();
+#ifndef VL_THREADED
+    if (configp->m_useOffloading) {
+        VL_FATAL_MT(__FILE__, __LINE__, "", "Cannot use trace offloading without VL_THREADED");
+    }
+#endif
+
+    // Configure trace base class
+    if (!firstModel) {
+        if (m_offload != configp->m_useOffloading) {
+            VL_FATAL_MT(__FILE__, __LINE__, "",
+                        "Either all or no models using the same trace file must use offloading");
+        }
+    }
+    m_offload = configp->m_useOffloading;
+    // If at least one model requests parallel tracing, then use it
+    m_parallel |= configp->m_useParallel;
+
+    if (VL_UNCOVERABLE(m_parallel && m_offload)) {  // LCOV_EXCL_START
+        VL_FATAL_MT(__FILE__, __LINE__, "", "Cannot use parallel tracing with offloading");
+    }  // LCOV_EXCL_STOP
+
+    // Configure format specific sub class
+    configure(*(configp.get()));
+}
+
+template <>
+void VerilatedTrace<VL_SUB_T, VL_BUF_T>::addCallbackRecord(std::vector<CallbackRecord>& cbVec,
+                                                           CallbackRecord&& cbRec)
+    VL_MT_SAFE_EXCLUDES(m_mutex) {
+    const VerilatedLockGuard lock{m_mutex};
+    cbVec.push_back(cbRec);
+}
+
+template <>
+void VerilatedTrace<VL_SUB_T, VL_BUF_T>::addInitCb(initCb_t cb, void* userp) VL_MT_SAFE {
+    addCallbackRecord(m_initCbs, CallbackRecord{cb, userp});
+}
+template <>
+void VerilatedTrace<VL_SUB_T, VL_BUF_T>::addFullCb(dumpCb_t cb, void* userp) VL_MT_SAFE {
+    addCallbackRecord(m_fullCbs, CallbackRecord{cb, userp});
+}
+template <>
+void VerilatedTrace<VL_SUB_T, VL_BUF_T>::addFullCb(dumpOffloadCb_t cb, void* userp) VL_MT_SAFE {
+    addCallbackRecord(m_fullOffloadCbs, CallbackRecord{cb, userp});
+}
+template <>
+void VerilatedTrace<VL_SUB_T, VL_BUF_T>::addChgCb(dumpCb_t cb, void* userp) VL_MT_SAFE {
+    addCallbackRecord(m_chgCbs, CallbackRecord{cb, userp});
+}
+template <>
+void VerilatedTrace<VL_SUB_T, VL_BUF_T>::addChgCb(dumpOffloadCb_t cb, void* userp) VL_MT_SAFE {
+    addCallbackRecord(m_chgOffloadCbs, CallbackRecord{cb, userp});
+}
+template <>
+void VerilatedTrace<VL_SUB_T, VL_BUF_T>::addCleanupCb(cleanupCb_t cb, void* userp) VL_MT_SAFE {
+    addCallbackRecord(m_cleanupCbs, CallbackRecord{cb, userp});
+}
+
+template <>
+void VerilatedTrace<VL_SUB_T, VL_BUF_T>::pushNamePrefix(const std::string& prefix) {
+    m_namePrefixStack.push_back(m_namePrefixStack.back() + prefix);
+}
+
+template <>
+void VerilatedTrace<VL_SUB_T, VL_BUF_T>::popNamePrefix(unsigned count) {
+    while (count--) m_namePrefixStack.pop_back();
+    assert(!m_namePrefixStack.empty());
+}
+
+//=========================================================================
+// Primitives converting binary values to strings...
+
+// All of these take a destination pointer where the string will be emitted,
+// and a value to convert. There are a couple of variants for efficiency.
+
+static inline void cvtCDataToStr(char* dstp, CData value) {
+#ifdef VL_HAVE_SSE2
+    // Similar to cvtSDataToStr but only the bottom 8 byte lanes are used
+    const __m128i a = _mm_cvtsi32_si128(value);
+    const __m128i b = _mm_unpacklo_epi8(a, a);
+    const __m128i c = _mm_shufflelo_epi16(b, 0);
+    const __m128i m = _mm_set1_epi64x(0x0102040810204080);
+    const __m128i d = _mm_cmpeq_epi8(_mm_and_si128(c, m), m);
+    const __m128i result = _mm_sub_epi8(_mm_set1_epi8('0'), d);
+    _mm_storel_epi64(reinterpret_cast<__m128i*>(dstp), result);
+#else
+    dstp[0] = '0' | static_cast<char>((value >> 7) & 1);
+    dstp[1] = '0' | static_cast<char>((value >> 6) & 1);
+    dstp[2] = '0' | static_cast<char>((value >> 5) & 1);
+    dstp[3] = '0' | static_cast<char>((value >> 4) & 1);
+    dstp[4] = '0' | static_cast<char>((value >> 3) & 1);
+    dstp[5] = '0' | static_cast<char>((value >> 2) & 1);
+    dstp[6] = '0' | static_cast<char>((value >> 1) & 1);
+    dstp[7] = '0' | static_cast<char>(value & 1);
+#endif
+}
+
+static inline void cvtSDataToStr(char* dstp, SData value) {
+#ifdef VL_HAVE_SSE2
+    // We want each bit in the 16-bit input value to end up in a byte lane
+    // within the 128-bit XMM register. Note that x86 is little-endian and we
+    // want the MSB of the input at the low address, so we will bit-reverse
+    // at the same time.
+
+    // Put value in bottom of 128-bit register a[15:0] = value
+    const __m128i a = _mm_cvtsi32_si128(value);
+    // Interleave bytes with themselves
+    // b[15: 0] = {2{a[ 7:0]}} == {2{value[ 7:0]}}
+    // b[31:16] = {2{a[15:8]}} == {2{value[15:8]}}
+    const __m128i b = _mm_unpacklo_epi8(a, a);
+    // Shuffle bottom 64 bits, note swapping high bytes with low bytes
+    // c[31: 0] = {2{b[31:16]}} == {4{value[15:8}}
+    // c[63:32] = {2{b[15: 0]}} == {4{value[ 7:0}}
+    const __m128i c = _mm_shufflelo_epi16(b, 0x05);
+    // Shuffle whole register
+    // d[ 63: 0] = {2{c[31: 0]}} == {8{value[15:8}}
+    // d[126:54] = {2{c[63:32]}} == {8{value[ 7:0}}
+    const __m128i d = _mm_shuffle_epi32(c, 0x50);
+    // Test each bit within the bytes, this sets each byte lane to 0
+    // if the bit for that lane is 0 and to 0xff if the bit is 1.
+    const __m128i m = _mm_set1_epi64x(0x0102040810204080);
+    const __m128i e = _mm_cmpeq_epi8(_mm_and_si128(d, m), m);
+    // Convert to ASCII by subtracting the masks from ASCII '0':
+    // '0' - 0 is '0', '0' - -1 is '1'
+    const __m128i result = _mm_sub_epi8(_mm_set1_epi8('0'), e);
+    // Store the 16 characters to the un-aligned buffer
+    _mm_storeu_si128(reinterpret_cast<__m128i*>(dstp), result);
+#else
+    cvtCDataToStr(dstp, value >> 8);
+    cvtCDataToStr(dstp + 8, value);
+#endif
+}
+
+static inline void cvtIDataToStr(char* dstp, IData value) {
+#ifdef VL_HAVE_AVX2
+    // Similar to cvtSDataToStr but the bottom 16-bits are processed in the
+    // top half of the YMM registerss
+    const __m256i a = _mm256_insert_epi32(_mm256_undefined_si256(), value, 0);
+    const __m256i b = _mm256_permute4x64_epi64(a, 0);
+    const __m256i s = _mm256_set_epi8(0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2,
+                                      2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3);
+    const __m256i c = _mm256_shuffle_epi8(b, s);
+    const __m256i m = _mm256_set1_epi64x(0x0102040810204080);
+    const __m256i d = _mm256_cmpeq_epi8(_mm256_and_si256(c, m), m);
+    const __m256i result = _mm256_sub_epi8(_mm256_set1_epi8('0'), d);
+    _mm256_storeu_si256(reinterpret_cast<__m256i*>(dstp), result);
+#else
+    cvtSDataToStr(dstp, value >> 16);
+    cvtSDataToStr(dstp + 16, value);
+#endif
+}
+
+static inline void cvtQDataToStr(char* dstp, QData value) {
+    cvtIDataToStr(dstp, value >> 32);
+    cvtIDataToStr(dstp + 32, value);
+}
+
+#define cvtEDataToStr cvtIDataToStr
+
+//=========================================================================
+// VerilatedTraceBuffer
+
+template <>
+VerilatedTraceBuffer<VL_BUF_T>::VerilatedTraceBuffer(Trace& owner)
+    : VL_BUF_T{owner}
+    , m_sigs_oldvalp{owner.m_sigs_oldvalp}
+    , m_sigs_enabledp{owner.m_sigs_enabledp} {}
+
+// These functions must write the new value back into the old value store,
+// and subsequently call the format specific emit* implementations. Note
+// that this file must be included in the format specific implementation, so
+// the emit* functions can be inlined for performance.
+
+template <>
+void VerilatedTraceBuffer<VL_BUF_T>::fullBit(uint32_t* oldp, CData newval) {
+    const uint32_t code = oldp - m_sigs_oldvalp;
+    *oldp = newval;  // Still copy even if not tracing so chg doesn't call full
+    if (VL_UNLIKELY(m_sigs_enabledp && !(VL_BITISSET_W(m_sigs_enabledp, code)))) return;
+    emitBit(code, newval);
+}
+
+template <>
+void VerilatedTraceBuffer<VL_BUF_T>::fullCData(uint32_t* oldp, CData newval, int bits) {
+    const uint32_t code = oldp - m_sigs_oldvalp;
+    *oldp = newval;  // Still copy even if not tracing so chg doesn't call full
+    if (VL_UNLIKELY(m_sigs_enabledp && !(VL_BITISSET_W(m_sigs_enabledp, code)))) return;
+    emitCData(code, newval, bits);
+}
+
+template <>
+void VerilatedTraceBuffer<VL_BUF_T>::fullSData(uint32_t* oldp, SData newval, int bits) {
+    const uint32_t code = oldp - m_sigs_oldvalp;
+    *oldp = newval;  // Still copy even if not tracing so chg doesn't call full
+    if (VL_UNLIKELY(m_sigs_enabledp && !(VL_BITISSET_W(m_sigs_enabledp, code)))) return;
+    emitSData(code, newval, bits);
+}
+
+template <>
+void VerilatedTraceBuffer<VL_BUF_T>::fullIData(uint32_t* oldp, IData newval, int bits) {
+    const uint32_t code = oldp - m_sigs_oldvalp;
+    *oldp = newval;  // Still copy even if not tracing so chg doesn't call full
+    if (VL_UNLIKELY(m_sigs_enabledp && !(VL_BITISSET_W(m_sigs_enabledp, code)))) return;
+    emitIData(code, newval, bits);
+}
+
+template <>
+void VerilatedTraceBuffer<VL_BUF_T>::fullQData(uint32_t* oldp, QData newval, int bits) {
+    const uint32_t code = oldp - m_sigs_oldvalp;
+    *reinterpret_cast<QData*>(oldp) = newval;
+    if (VL_UNLIKELY(m_sigs_enabledp && !(VL_BITISSET_W(m_sigs_enabledp, code)))) return;
+    emitQData(code, newval, bits);
+}
+
+template <>
+void VerilatedTraceBuffer<VL_BUF_T>::fullWData(uint32_t* oldp, const WData* newvalp, int bits) {
+    const uint32_t code = oldp - m_sigs_oldvalp;
+    for (int i = 0; i < VL_WORDS_I(bits); ++i) oldp[i] = newvalp[i];
+    if (VL_UNLIKELY(m_sigs_enabledp && !(VL_BITISSET_W(m_sigs_enabledp, code)))) return;
+    emitWData(code, newvalp, bits);
+}
+
+template <>
+void VerilatedTraceBuffer<VL_BUF_T>::fullDouble(uint32_t* oldp, double newval) {
+    const uint32_t code = oldp - m_sigs_oldvalp;
+    *reinterpret_cast<double*>(oldp) = newval;
+    if (VL_UNLIKELY(m_sigs_enabledp && !(VL_BITISSET_W(m_sigs_enabledp, code)))) return;
+    // cppcheck-suppress invalidPointerCast
+    emitDouble(code, newval);
+}
+
+#ifdef VL_THREADED
+//=========================================================================
+// VerilatedTraceOffloadBuffer
+
+template <>
+VerilatedTraceOffloadBuffer<VL_BUF_T>::VerilatedTraceOffloadBuffer(VL_SUB_T& owner)
+    : VerilatedTraceBuffer<VL_BUF_T>{owner}
+    , m_offloadBufferWritep{owner.m_offloadBufferWritep}
+    , m_offloadBufferEndp{owner.m_offloadBufferEndp} {
+    if (m_offloadBufferWritep) {
+        using This = VerilatedTraceBuffer<VL_BUF_T>*;
+        // Tack on the buffer address
+        static_assert(2 * sizeof(uint32_t) >= sizeof(This),
+                      "This should be enough on all plafrorms");
+        *m_offloadBufferWritep++ = VerilatedTraceOffloadCommand::TRACE_BUFFER;
+        *reinterpret_cast<This*>(m_offloadBufferWritep) = static_cast<This>(this);
+        m_offloadBufferWritep += 2;
+    }
+}
+#endif
+
+#endif  // VL_CPPCHECK
@@ -73,7 +73,7 @@ extern std::string VL_TO_STRING_W(int words, const WDataInP obj);
 //===================================================================
 // Shuffle RNG

-extern vluint64_t vl_rand64() VL_MT_SAFE;
+extern uint64_t vl_rand64() VL_MT_SAFE;

 class VlURNG final {
 public:
@@ -91,9 +91,9 @@ class VlReadMem final {
    const int m_bits;  // Bit width of values
    const std::string& m_filename;  // Filename
    const QData m_end;  // End address (as specified by user)
-    FILE* m_fp;  // File handle for filename
-    QData m_addr;  // Next address to read
-    int m_linenum;  // Line number last read from file
+    FILE* m_fp = nullptr;  // File handle for filename
+    QData m_addr = 0;  // Next address to read
+    int m_linenum = 0;  // Line number last read from file
    bool m_anyAddr = false;  // Had address directive in the file
 public:
    VlReadMem(bool hex, int bits, const std::string& filename, QData start, QData end);
@@ -107,8 +107,8 @@ public:
 class VlWriteMem final {
    const bool m_hex;  // Hex format
    const int m_bits;  // Bit width of values
-    FILE* m_fp;  // File handle for filename
-    QData m_addr;  // Next address to write
+    FILE* m_fp = nullptr;  // File handle for filename
+    QData m_addr = 0;  // Next address to write
 public:
    VlWriteMem(bool hex, int bits, const std::string& filename, QData start, QData end);
    ~VlWriteMem();
@@ -131,7 +131,8 @@ public:

 static int _vl_cmp_w(int words, WDataInP const lwp, WDataInP const rwp) VL_MT_SAFE;

-template <std::size_t T_Words> struct VlWide final {
+template <std::size_t T_Words>
+struct VlWide final {
    // MEMBERS
    // This should be the only data member, otherwise generated static initializers need updating
    EData m_storage[T_Words];  // Contents of the packed array
@@ -163,7 +164,8 @@ VlWide<T_Words>& VL_CVT_W_A(const WDataInP inp, const VlWide<T_Words>&) {
    return *((VlWide<T_Words>*)inp);
 }

-template <std::size_t T_Words> std::string VL_TO_STRING(const VlWide<T_Words>& obj) {
+template <std::size_t T_Words>
+std::string VL_TO_STRING(const VlWide<T_Words>& obj) {
    return VL_TO_STRING_W(T_Words, obj.data());
 }

@@ -174,7 +176,8 @@ template <std::size_t T_Words> std::string VL_TO_STRING(const VlWide<T_Words>& o
 //
 // Bound here is the maximum size() allowed, e.g. 1 + SystemVerilog bound
 // For dynamic arrays it is always zero
-template <class T_Value, size_t T_MaxSize = 0> class VlQueue final {
+template <class T_Value, size_t T_MaxSize = 0>
+class VlQueue final {
 private:
    // TYPES
    using Deque = std::deque<T_Value>;
@@ -199,7 +202,8 @@ public:

    // Standard copy constructor works. Verilog: assoca = assocb
    // Also must allow conversion from a different T_MaxSize queue
-    template <size_t U_MaxSize = 0> VlQueue operator=(const VlQueue<T_Value, U_MaxSize>& rhs) {
+    template <size_t U_MaxSize = 0>
+    VlQueue operator=(const VlQueue<T_Value, U_MaxSize>& rhs) {
        m_deque = rhs.privateDeque();
        if (VL_UNLIKELY(T_MaxSize && T_MaxSize < m_deque.size())) m_deque.resize(T_MaxSize - 1);
        return *this;
@@ -241,7 +245,7 @@ public:
    int size() const { return m_deque.size(); }
    // Clear array. Verilog: function void delete([input index])
    void clear() { m_deque.clear(); }
-    void erase(vlsint32_t index) {
+    void erase(int32_t index) {
        if (VL_LIKELY(index >= 0 && index < m_deque.size()))
            m_deque.erase(m_deque.begin() + index);
    }
@@ -288,8 +292,8 @@ public:
    // Setting. Verilog: assoc[index] = v
    // Can't just overload operator[] or provide a "at" reference to set,
    // because we need to be able to insert only when the value is set
-    T_Value& at(vlsint32_t index) {
-        static T_Value s_throwAway;
+    T_Value& at(int32_t index) {
+        static VL_THREAD_LOCAL T_Value s_throwAway;
        // Needs to work for dynamic arrays, so does not use T_MaxSize
        if (VL_UNLIKELY(index < 0 || index >= m_deque.size())) {
            s_throwAway = atDefault();
@@ -299,8 +303,8 @@ public:
        }
    }
    // Accessing. Verilog: v = assoc[index]
-    const T_Value& at(vlsint32_t index) const {
-        static T_Value s_throwAway;
+    const T_Value& at(int32_t index) const {
+        static VL_THREAD_LOCAL T_Value s_throwAway;
        // Needs to work for dynamic arrays, so does not use T_MaxSize
        if (VL_UNLIKELY(index < 0 || index >= m_deque.size())) {
            return atDefault();
@@ -309,18 +313,18 @@ public:
        }
    }
    // function void q.insert(index, value);
-    void insert(vlsint32_t index, const T_Value& value) {
+    void insert(int32_t index, const T_Value& value) {
        if (VL_UNLIKELY(index < 0 || index >= m_deque.size())) return;
        m_deque.insert(m_deque.begin() + index, value);
    }

    // Return slice q[lsb:msb]
-    VlQueue slice(vlsint32_t lsb, vlsint32_t msb) const {
+    VlQueue slice(int32_t lsb, int32_t msb) const {
        VlQueue out;
        if (VL_UNLIKELY(lsb < 0)) lsb = 0;
        if (VL_UNLIKELY(lsb >= m_deque.size())) lsb = m_deque.size() - 1;
        if (VL_UNLIKELY(msb >= m_deque.size())) msb = m_deque.size() - 1;
-        for (vlsint32_t i = lsb; i <= msb; ++i) out.push_back(m_deque[i]);
+        for (int32_t i = lsb; i <= msb; ++i) out.push_back(m_deque[i]);
        return out;
    }

@@ -330,7 +334,8 @@ public:

    // Methods
    void sort() { std::sort(m_deque.begin(), m_deque.end()); }
-    template <typename Func> void sort(Func with_func) {
+    template <typename Func>
+    void sort(Func with_func) {
        // with_func returns arbitrary type to use for the sort comparison
        std::sort(m_deque.begin(), m_deque.end(), [=](const T_Value& a, const T_Value& b) {
            // index number is meaninless with sort, as it changes
@@ -338,7 +343,8 @@ public:
        });
    }
    void rsort() { std::sort(m_deque.rbegin(), m_deque.rend()); }
-    template <typename Func> void rsort(Func with_func) {
+    template <typename Func>
+    void rsort(Func with_func) {
        // with_func returns arbitrary type to use for the sort comparison
        std::sort(m_deque.rbegin(), m_deque.rend(), [=](const T_Value& a, const T_Value& b) {
            // index number is meaninless with sort, as it changes
@@ -373,7 +379,8 @@ public:
        }
        return out;
    }
-    template <typename Func> VlQueue find(Func with_func) const {
+    template <typename Func>
+    VlQueue find(Func with_func) const {
        VlQueue out;
        IData index = 0;
        for (const auto& i : m_deque) {
@@ -382,7 +389,8 @@ public:
        }
        return out;
    }
-    template <typename Func> VlQueue<IData> find_index(Func with_func) const {
+    template <typename Func>
+    VlQueue<IData> find_index(Func with_func) const {
        VlQueue<IData> out;
        IData index = 0;
        for (const auto& i : m_deque) {
@@ -391,7 +399,8 @@ public:
        }
        return out;
    }
-    template <typename Func> VlQueue find_first(Func with_func) const {
+    template <typename Func>
+    VlQueue find_first(Func with_func) const {
        // Can't use std::find_if as need index number
        IData index = 0;
        for (const auto& i : m_deque) {
@@ -400,7 +409,8 @@ public:
        }
        return VlQueue{};
    }
-    template <typename Func> VlQueue<IData> find_first_index(Func with_func) const {
+    template <typename Func>
+    VlQueue<IData> find_first_index(Func with_func) const {
        IData index = 0;
        for (const auto& i : m_deque) {
            if (with_func(index, i)) return VlQueue<IData>::cons(index);
@@ -408,18 +418,20 @@ public:
        }
        return VlQueue<IData>{};
    }
-    template <typename Func> VlQueue find_last(Func with_func) const {
+    template <typename Func>
+    VlQueue find_last(Func with_func) const {
        IData index = m_deque.size() - 1;
-        for (auto it = m_deque.rbegin(); it != m_deque.rend(); ++it) {
-            if (with_func(index, *it)) return VlQueue::cons(*it);
+        for (auto& item : vlstd::reverse_view(m_deque)) {
+            if (with_func(index, item)) return VlQueue::cons(item);
            --index;
        }
        return VlQueue{};
    }
-    template <typename Func> VlQueue<IData> find_last_index(Func with_func) const {
+    template <typename Func>
+    VlQueue<IData> find_last_index(Func with_func) const {
        IData index = m_deque.size() - 1;
-        for (auto it = m_deque.rbegin(); it != m_deque.rend(); ++it) {
-            if (with_func(index, *it)) return VlQueue<IData>::cons(index);
+        for (auto& item : vlstd::reverse_view(m_deque)) {
+            if (with_func(index, item)) return VlQueue<IData>::cons(index);
            --index;
        }
        return VlQueue<IData>{};
@@ -442,7 +454,8 @@ public:
        for (const auto& i : m_deque) out += i;
        return out;
    }
-    template <typename Func> T_Value r_sum(Func with_func) const {
+    template <typename Func>
+    T_Value r_sum(Func with_func) const {
        T_Value out(0);  // Type must have assignment operator
        IData index = 0;
        for (const auto& i : m_deque) out += with_func(index++, i);
@@ -456,7 +469,8 @@ public:
        for (; it != m_deque.end(); ++it) out *= *it;
        return out;
    }
-    template <typename Func> T_Value r_product(Func with_func) const {
+    template <typename Func>
+    T_Value r_product(Func with_func) const {
        if (m_deque.empty()) return T_Value(0);
        auto it = m_deque.begin();
        IData index = 0;
@@ -474,7 +488,8 @@ public:
        for (; it != m_deque.end(); ++it) out &= *it;
        return out;
    }
-    template <typename Func> T_Value r_and(Func with_func) const {
+    template <typename Func>
+    T_Value r_and(Func with_func) const {
        if (m_deque.empty()) return T_Value(0);
        auto it = m_deque.begin();
        IData index = 0;
@@ -489,7 +504,8 @@ public:
        for (const auto& i : m_deque) out |= i;
        return out;
    }
-    template <typename Func> T_Value r_or(Func with_func) const {
+    template <typename Func>
+    T_Value r_or(Func with_func) const {
        T_Value out(0);  // Type must have assignment operator
        IData index = 0;
        for (const auto& i : m_deque) out |= with_func(index++, i);
@@ -500,7 +516,8 @@ public:
        for (const auto& i : m_deque) out ^= i;
        return out;
    }
-    template <typename Func> T_Value r_xor(Func with_func) const {
+    template <typename Func>
+    T_Value r_xor(Func with_func) const {
        T_Value out(0);  // Type must have assignment operator
        IData index = 0;
        for (const auto& i : m_deque) out ^= with_func(index++, i);
@@ -520,7 +537,8 @@ public:
    }
 };

-template <class T_Value> std::string VL_TO_STRING(const VlQueue<T_Value>& obj) {
+template <class T_Value>
+std::string VL_TO_STRING(const VlQueue<T_Value>& obj) {
    return obj.to_string();
 }

@@ -529,7 +547,8 @@ template <class T_Value> std::string VL_TO_STRING(const VlQueue<T_Value>& obj) {
 // There are no multithreaded locks on this; the base variable must
 // be protected by other means
 //
-template <class T_Key, class T_Value> class VlAssocArray final {
+template <class T_Key, class T_Value>
+class VlAssocArray final {
 private:
    // TYPES
    using Map = std::map<T_Key, T_Value>;
@@ -654,19 +673,22 @@ public:
        }
        return out;
    }
-    template <typename Func> VlQueue<T_Value> find(Func with_func) const {
+    template <typename Func>
+    VlQueue<T_Value> find(Func with_func) const {
        VlQueue<T_Value> out;
        for (const auto& i : m_map)
            if (with_func(i.first, i.second)) out.push_back(i.second);
        return out;
    }
-    template <typename Func> VlQueue<T_Key> find_index(Func with_func) const {
+    template <typename Func>
+    VlQueue<T_Key> find_index(Func with_func) const {
        VlQueue<T_Key> out;
        for (const auto& i : m_map)
            if (with_func(i.first, i.second)) out.push_back(i.first);
        return out;
    }
-    template <typename Func> VlQueue<T_Value> find_first(Func with_func) const {
+    template <typename Func>
+    VlQueue<T_Value> find_first(Func with_func) const {
        const auto it
            = std::find_if(m_map.begin(), m_map.end(), [=](const std::pair<T_Key, T_Value>& i) {
                  return with_func(i.first, i.second);
@@ -674,7 +696,8 @@ public:
        if (it == m_map.end()) return VlQueue<T_Value>{};
        return VlQueue<T_Value>::cons(it->second);
    }
-    template <typename Func> VlQueue<T_Key> find_first_index(Func with_func) const {
+    template <typename Func>
+    VlQueue<T_Key> find_first_index(Func with_func) const {
        const auto it
            = std::find_if(m_map.begin(), m_map.end(), [=](const std::pair<T_Key, T_Value>& i) {
                  return with_func(i.first, i.second);
@@ -682,7 +705,8 @@ public:
        if (it == m_map.end()) return VlQueue<T_Value>{};
        return VlQueue<T_Key>::cons(it->first);
    }
-    template <typename Func> VlQueue<T_Value> find_last(Func with_func) const {
+    template <typename Func>
+    VlQueue<T_Value> find_last(Func with_func) const {
        const auto it
            = std::find_if(m_map.rbegin(), m_map.rend(), [=](const std::pair<T_Key, T_Value>& i) {
                  return with_func(i.first, i.second);
@@ -690,7 +714,8 @@ public:
        if (it == m_map.rend()) return VlQueue<T_Value>{};
        return VlQueue<T_Value>::cons(it->second);
    }
-    template <typename Func> VlQueue<T_Key> find_last_index(Func with_func) const {
+    template <typename Func>
+    VlQueue<T_Key> find_last_index(Func with_func) const {
        const auto it
            = std::find_if(m_map.rbegin(), m_map.rend(), [=](const std::pair<T_Key, T_Value>& i) {
                  return with_func(i.first, i.second);
@@ -724,7 +749,8 @@ public:
        for (const auto& i : m_map) out += i.second;
        return out;
    }
-    template <typename Func> T_Value r_sum(Func with_func) const {
+    template <typename Func>
+    T_Value r_sum(Func with_func) const {
        T_Value out(0);  // Type must have assignment operator
        for (const auto& i : m_map) out += with_func(i.first, i.second);
        return out;
@@ -737,7 +763,8 @@ public:
        for (; it != m_map.end(); ++it) out *= it->second;
        return out;
    }
-    template <typename Func> T_Value r_product(Func with_func) const {
+    template <typename Func>
+    T_Value r_product(Func with_func) const {
        if (m_map.empty()) return T_Value(0);
        auto it = m_map.begin();
        T_Value out{with_func(it->first, it->second)};
@@ -753,7 +780,8 @@ public:
        for (; it != m_map.end(); ++it) out &= it->second;
        return out;
    }
-    template <typename Func> T_Value r_and(Func with_func) const {
+    template <typename Func>
+    T_Value r_and(Func with_func) const {
        if (m_map.empty()) return T_Value(0);
        auto it = m_map.begin();
        T_Value out{with_func(it->first, it->second)};
@@ -766,7 +794,8 @@ public:
        for (const auto& i : m_map) out |= i.second;
        return out;
    }
-    template <typename Func> T_Value r_or(Func with_func) const {
+    template <typename Func>
+    T_Value r_or(Func with_func) const {
        T_Value out(0);  // Type must have assignment operator
        for (const auto& i : m_map) out |= with_func(i.first, i.second);
        return out;
@@ -776,7 +805,8 @@ public:
        for (const auto& i : m_map) out ^= i.second;
        return out;
    }
-    template <typename Func> T_Value r_xor(Func with_func) const {
+    template <typename Func>
+    T_Value r_xor(Func with_func) const {
        T_Value out(0);  // Type must have assignment operator
        for (const auto& i : m_map) out ^= with_func(i.first, i.second);
        return out;
@@ -839,7 +869,8 @@ void VL_WRITEMEM_N(bool hex, int bits, const std::string& filename,
 /// This class may get exposed to a Verilated Model's top I/O, if the top
 /// IO has an unpacked array.

-template <class T_Value, std::size_t T_Depth> struct VlUnpacked final {
+template <class T_Value, std::size_t T_Depth>
+struct VlUnpacked final {
    // MEMBERS
    // This should be the only data member, otherwise generated static initializers need updating
    T_Value m_storage[T_Depth];  // Contents of the unpacked array
@@ -38,13 +38,13 @@
 # include <unistd.h>
 #endif

-#ifndef O_LARGEFILE  // For example on WIN32
+#ifndef O_LARGEFILE  // WIN32 headers omit this
 # define O_LARGEFILE 0
 #endif
-#ifndef O_NONBLOCK
+#ifndef O_NONBLOCK  // WIN32 headers omit this
 # define O_NONBLOCK 0
 #endif
-#ifndef O_CLOEXEC
+#ifndef O_CLOEXEC  // WIN32 headers omit this
 # define O_CLOEXEC 0
 #endif

@@ -62,12 +62,24 @@ constexpr unsigned VL_TRACE_MAX_VCD_CODE_SIZE = 5;  // Maximum length of a VCD s
 // cache-lines.
 constexpr unsigned VL_TRACE_SUFFIX_ENTRY_SIZE = 8;  // Size of a suffix entry

+//=============================================================================
+// Utility functions: TODO: put these in a common place and share them.
+
+template <size_t N>
+static size_t roundUpToMultipleOf(size_t value) {
+    static_assert((N & (N - 1)) == 0, "'N' must be a power of 2");
+    size_t mask = N - 1;
+    return (value + mask) & ~mask;
+}
+
 //=============================================================================
 // Specialization of the generics for this trace format

-#define VL_DERIVED_T VerilatedVcd
-#include "verilated_trace_imp.cpp"
-#undef VL_DERIVED_T
+#define VL_SUB_T VerilatedVcd
+#define VL_BUF_T VerilatedVcdBuffer
+#include "verilated_trace_imp.h"
+#undef VL_SUB_T
+#undef VL_BUF_T

 //=============================================================================
 //=============================================================================
@@ -108,13 +120,13 @@ void VerilatedVcd::open(const char* filename) VL_MT_SAFE_EXCLUDES(m_mutex) {
    // Set member variables
    m_filename = filename;  // "" is ok, as someone may overload open

-    openNextImp(m_rolloverMB != 0);
+    openNextImp(m_rolloverSize != 0);
    if (!isOpen()) return;

    dumpHeader();

    // When using rollover, the first chunk contains the header only.
-    if (m_rolloverMB) openNextImp(true);
+    if (m_rolloverSize) openNextImp(true);
 }

 void VerilatedVcd::openNext(bool incFilename) VL_MT_SAFE_EXCLUDES(m_mutex) {
@@ -168,11 +180,11 @@ void VerilatedVcd::openNextImp(bool incFilename) {
 }

 bool VerilatedVcd::preChangeDump() {
-    if (VL_UNLIKELY(m_rolloverMB && m_wroteBytes > m_rolloverMB)) openNextImp(true);
+    if (VL_UNLIKELY(m_rolloverSize && m_wroteBytes > m_rolloverSize)) openNextImp(true);
    return isOpen();
 }

-void VerilatedVcd::emitTimeChange(vluint64_t timeui) {
+void VerilatedVcd::emitTimeChange(uint64_t timeui) {
    printStr("#");
    printQuad(timeui);
    printStr("\n");
@@ -183,7 +195,7 @@ void VerilatedVcd::makeNameMap() {
    deleteNameMap();
    m_namemapp = new NameMap;

-    VerilatedTrace<VerilatedVcd>::traceInit();
+    Super::traceInit();

    // Though not speced, it's illegal to generate a vcd with signals
    // not under any module - it crashes at least two viewers.
@@ -218,13 +230,19 @@ VerilatedVcd::~VerilatedVcd() {
    if (m_wrBufp) VL_DO_CLEAR(delete[] m_wrBufp, m_wrBufp = nullptr);
    deleteNameMap();
    if (m_filep && m_fileNewed) VL_DO_CLEAR(delete m_filep, m_filep = nullptr);
+#ifdef VL_THREADED
+    if (parallel()) {
+        assert(m_numBuffers == m_freeBuffers.size());
+        for (auto& pair : m_freeBuffers) VL_DO_CLEAR(delete[] pair.first, pair.first = nullptr);
+    }
+#endif
 }

 void VerilatedVcd::closePrev() {
    // This function is on the flush() call path
    if (!isOpen()) return;

-    VerilatedTrace<VerilatedVcd>::flushBase();
+    Super::flushBase();
    bufferFlush();
    m_isOpen = false;
    m_filep->close();
@@ -245,20 +263,15 @@ void VerilatedVcd::close() VL_MT_SAFE_EXCLUDES(m_mutex) {
    // This function is on the flush() call path
    const VerilatedLockGuard lock{m_mutex};
    if (!isOpen()) return;
-    if (m_evcd) {
-        printStr("$vcdclose ");
-        printQuad(timeLastDump());
-        printStr(" $end\n");
-    }
    closePrev();
-    // closePrev() called VerilatedTrace<VerilatedVcd>::flush(), so we just
+    // closePrev() called Super::flush(), so we just
    // need to shut down the tracing thread here.
-    VerilatedTrace<VerilatedVcd>::closeBase();
+    Super::closeBase();
 }

 void VerilatedVcd::flush() VL_MT_SAFE_EXCLUDES(m_mutex) {
    const VerilatedLockGuard lock{m_mutex};
-    VerilatedTrace<VerilatedVcd>::flushBase();
+    Super::flushBase();
    bufferFlush();
 }

@@ -270,19 +283,19 @@ void VerilatedVcd::printStr(const char* str) {
    }
 }

-void VerilatedVcd::printQuad(vluint64_t n) {
+void VerilatedVcd::printQuad(uint64_t n) {
    constexpr size_t LEN_STR_QUAD = 40;
    char buf[LEN_STR_QUAD];
    VL_SNPRINTF(buf, LEN_STR_QUAD, "%" PRIu64, n);
    printStr(buf);
 }

-void VerilatedVcd::bufferResize(vluint64_t minsize) {
+void VerilatedVcd::bufferResize(size_t minsize) {
    // minsize is size of largest write.  We buffer at least 8 times as much data,
    // writing when we are 3/4 full (with thus 2*minsize remaining free)
    if (VL_UNLIKELY(minsize > m_wrChunkSize)) {
        const char* oldbufp = m_wrBufp;
-        m_wrChunkSize = minsize * 2;
+        m_wrChunkSize = roundUpToMultipleOf<1024>(minsize * 2);
        m_wrBufp = new char[m_wrChunkSize * 8];
        std::memcpy(m_wrBufp, oldbufp, m_writep - oldbufp);
        m_writep = m_wrBufp + (m_writep - oldbufp);
@@ -292,7 +305,7 @@ void VerilatedVcd::bufferResize(vluint64_t minsize) {
 }

 void VerilatedVcd::bufferFlush() VL_MT_UNSAFE_ONE {
-    // This function can be called from the trace thread
+    // This function can be called from the trace offload thread
    // This function is on the flush() call path
    // We add output data to m_writep.
    // When it gets nearly full we dump it using this routine which calls write()
@@ -328,7 +341,7 @@ void VerilatedVcd::bufferFlush() VL_MT_UNSAFE_ONE {
 //=============================================================================
 // VCD string code

-char* VerilatedVcd::writeCode(char* writep, vluint32_t code) {
+char* VerilatedVcd::writeCode(char* writep, uint32_t code) {
    *writep++ = static_cast<char>('!' + code % 94);
    code /= 94;
    while (code) {
@@ -459,18 +472,22 @@ void VerilatedVcd::dumpHeader() {
    deleteNameMap();
 }

-void VerilatedVcd::declare(vluint32_t code, const char* name, const char* wirep, bool array,
+void VerilatedVcd::declare(uint32_t code, const char* name, const char* wirep, bool array,
                           int arraynum, bool tri, bool bussed, int msb, int lsb) {
    const int bits = ((msb > lsb) ? (msb - lsb) : (lsb - msb)) + 1;

-    VerilatedTrace<VerilatedVcd>::declCode(code, bits, tri);
+    const bool enabled = Super::declCode(code, name, bits, tri);

    if (m_suffixes.size() <= nextCode() * VL_TRACE_SUFFIX_ENTRY_SIZE) {
        m_suffixes.resize(nextCode() * VL_TRACE_SUFFIX_ENTRY_SIZE * 2, 0);
    }

-    // Make sure write buffer is large enough (one character per bit), plus header
-    bufferResize(bits + 1024);
+    // Keep upper bound on bytes a single signal cna emit into the buffer
+    m_maxSignalBytes = std::max<size_t>(m_maxSignalBytes, bits + 32);
+    // Make sure write buffer is large enough, plus header
+    bufferResize(m_maxSignalBytes + 1024);
+
+    if (!enabled) return;

    // Split name into basename
    // Spaces and tabs aren't legal in VCD signal names, so:
@@ -495,38 +512,29 @@ void VerilatedVcd::declare(vluint32_t code, const char* name, const char* wirep,

    // Print reference
    std::string decl = "$var ";
-    if (m_evcd) {
-        decl += "port";
-    } else {
-        decl += wirep;  // usually "wire"
-    }
+    decl += wirep;  // usually "wire"

    constexpr size_t bufsize = 1000;
    char buf[bufsize];
    VL_SNPRINTF(buf, bufsize, " %2d ", bits);
    decl += buf;
-    if (m_evcd) {
-        VL_SNPRINTF(buf, bufsize, "<%u", code);
-        decl += buf;
-    } else {
-        // Add string code to decl
-        char* const endp = writeCode(buf, code);
-        *endp = '\0';
-        decl += buf;
-        // Build suffix array entry
-        char* const entryp = &m_suffixes[code * VL_TRACE_SUFFIX_ENTRY_SIZE];
-        const size_t length = endp - buf;
-        assert(length <= VL_TRACE_MAX_VCD_CODE_SIZE);
-        // 1 bit values don't have a ' ' separator between value and string code
-        const bool isBit = bits == 1;
-        entryp[0] = ' ';  // Separator
-        // Use memcpy as we checked size above, and strcpy is flagged unsafe
-        std::memcpy(entryp + !isBit, buf,
-                    std::strlen(buf));  // Code (overwrite separator if isBit)
-        entryp[length + !isBit] = '\n';  // Replace '\0' with line termination '\n'
-        // Set length of suffix (used to increment write pointer)
-        entryp[VL_TRACE_SUFFIX_ENTRY_SIZE - 1] = !isBit + length + 1;
-    }
+    // Add string code to decl
+    char* const endp = writeCode(buf, code);
+    *endp = '\0';
+    decl += buf;
+    // Build suffix array entry
+    char* const entryp = &m_suffixes[code * VL_TRACE_SUFFIX_ENTRY_SIZE];
+    const size_t length = endp - buf;
+    assert(length <= VL_TRACE_MAX_VCD_CODE_SIZE);
+    // 1 bit values don't have a ' ' separator between value and string code
+    const bool isBit = bits == 1;
+    entryp[0] = ' ';  // Separator
+    // Use memcpy as we checked size above, and strcpy is flagged unsafe
+    std::memcpy(entryp + !isBit, buf,
+                std::strlen(buf));  // Code (overwrite separator if isBit)
+    entryp[length + !isBit] = '\n';  // Replace '\0' with line termination '\n'
+    // Set length of suffix (used to increment write pointer)
+    entryp[VL_TRACE_SUFFIX_ENTRY_SIZE - 1] = !isBit + length + 1;
    decl += " ";
    decl += basename;
    if (array) {
@@ -542,56 +550,99 @@ void VerilatedVcd::declare(vluint32_t code, const char* name, const char* wirep,
    m_namemapp->emplace(hiername, decl);
 }

-void VerilatedVcd::declBit(vluint32_t code, const char* name, bool array, int arraynum) {
+void VerilatedVcd::declBit(uint32_t code, const char* name, bool array, int arraynum) {
    declare(code, name, "wire", array, arraynum, false, false, 0, 0);
 }
-void VerilatedVcd::declBus(vluint32_t code, const char* name, bool array, int arraynum, int msb,
+void VerilatedVcd::declBus(uint32_t code, const char* name, bool array, int arraynum, int msb,
                           int lsb) {
    declare(code, name, "wire", array, arraynum, false, true, msb, lsb);
 }
-void VerilatedVcd::declQuad(vluint32_t code, const char* name, bool array, int arraynum, int msb,
+void VerilatedVcd::declQuad(uint32_t code, const char* name, bool array, int arraynum, int msb,
                            int lsb) {
    declare(code, name, "wire", array, arraynum, false, true, msb, lsb);
 }
-void VerilatedVcd::declArray(vluint32_t code, const char* name, bool array, int arraynum, int msb,
+void VerilatedVcd::declArray(uint32_t code, const char* name, bool array, int arraynum, int msb,
                             int lsb) {
    declare(code, name, "wire", array, arraynum, false, true, msb, lsb);
 }
-void VerilatedVcd::declDouble(vluint32_t code, const char* name, bool array, int arraynum) {
+void VerilatedVcd::declDouble(uint32_t code, const char* name, bool array, int arraynum) {
    declare(code, name, "real", array, arraynum, false, false, 63, 0);
 }
-#ifdef VL_TRACE_VCD_OLD_API
-void VerilatedVcd::declTriBit(vluint32_t code, const char* name, bool array, int arraynum) {
-    declare(code, name, "wire", array, arraynum, true, false, 0, 0);
-}
-void VerilatedVcd::declTriBus(vluint32_t code, const char* name, bool array, int arraynum, int msb,
-                              int lsb) {
-    declare(code, name, "wire", array, arraynum, true, true, msb, lsb);
-}
-void VerilatedVcd::declTriQuad(vluint32_t code, const char* name, bool array, int arraynum,
-                               int msb, int lsb) {
-    declare(code, name, "wire", array, arraynum, true, true, msb, lsb);
-}
-void VerilatedVcd::declTriArray(vluint32_t code, const char* name, bool array, int arraynum,
-                                int msb, int lsb) {
-    declare(code, name, "wire", array, arraynum, true, true, msb, lsb);
-}
-#endif  //  VL_TRACE_VCD_OLD_API

 //=============================================================================
-// Trace rendering prinitives
+// Get/commit trace buffer

-static inline void
-VerilatedVcdCCopyAndAppendNewLine(char* writep, const char* suffixp) VL_ATTR_NO_SANITIZE_ALIGN;
+VerilatedVcd::Buffer* VerilatedVcd::getTraceBuffer() {
+    VerilatedVcd::Buffer* const bufp = new Buffer{*this};
+#ifdef VL_THREADED
+    if (parallel()) {
+        // Note: This is called from VeriltedVcd::dump, which already holds the lock
+        // If no buffer available, allocate a new one
+        if (m_freeBuffers.empty()) {
+            constexpr size_t pageSize = 4096;
+            // 4 * m_maxSignalBytes, so we can reserve 2 * m_maxSignalBytes at the end for safety
+            size_t startingSize = roundUpToMultipleOf<pageSize>(4 * m_maxSignalBytes);
+            m_freeBuffers.emplace_back(new char[startingSize], startingSize);
+            ++m_numBuffers;
+        }
+        // Grab a buffer
+        const auto pair = m_freeBuffers.back();
+        m_freeBuffers.pop_back();
+        // Initialize
+        bufp->m_writep = bufp->m_bufp = pair.first;
+        bufp->m_size = pair.second;
+        bufp->adjustGrowp();
+    }
+#endif
+    // Return the buffer
+    return bufp;
+}

-static inline void VerilatedVcdCCopyAndAppendNewLine(char* writep, const char* suffixp) {
+void VerilatedVcd::commitTraceBuffer(VerilatedVcd::Buffer* bufp) {
+    if (parallel()) {
+#if VL_THREADED
+        // Note: This is called from VeriltedVcd::dump, which already holds the lock
+        // Resize output buffer. Note, we use the full size of the trace buffer, as
+        // this is a lot more stable than the actual occupancy of the trace buffer.
+        // This helps us to avoid re-allocations due to small size changes.
+        bufferResize(bufp->m_size);
+        // Compute occupancy of buffer
+        const size_t usedSize = bufp->m_writep - bufp->m_bufp;
+        // Copy to output buffer
+        std::memcpy(m_writep, bufp->m_bufp, usedSize);
+        // Adjust write pointer
+        m_writep += usedSize;
+        // Flush if necessary
+        bufferCheck();
+        // Put buffer back on free list
+        m_freeBuffers.emplace_back(bufp->m_bufp, bufp->m_size);
+#else
+        VL_FATAL_MT(__FILE__, __LINE__, "", "Unreachable");
+#endif
+    } else {
+        // Needs adjusting for emitTimeChange
+        m_writep = bufp->m_writep;
+    }
+    delete bufp;
+}
+
+//=============================================================================
+// VerilatedVcdBuffer implementation
+
+//=============================================================================
+// Trace rendering primitives
+
+static void VerilatedVcdCCopyAndAppendNewLine(char* writep,
+                                              const char* suffixp) VL_ATTR_NO_SANITIZE_ALIGN;
+
+static void VerilatedVcdCCopyAndAppendNewLine(char* writep, const char* suffixp) {
    // Copy the whole suffix (this avoid having hard to predict branches which
    // helps a lot). Note: The maximum length of the suffix is
    // VL_TRACE_MAX_VCD_CODE_SIZE + 2 == 7, but we unroll this here for speed.
 #ifdef VL_X86_64
    // Copy the whole 8 bytes in one go, this works on little-endian machines
    // supporting unaligned stores.
-    *reinterpret_cast<vluint64_t*>(writep) = *reinterpret_cast<const vluint64_t*>(suffixp);
+    *reinterpret_cast<uint64_t*>(writep) = *reinterpret_cast<const uint64_t*>(suffixp);
 #else
    // Portable variant
    writep[0] = suffixp[0];
@@ -604,25 +655,59 @@ static inline void VerilatedVcdCCopyAndAppendNewLine(char* writep, const char* s
 #endif
 }

-void VerilatedVcd::finishLine(vluint32_t code, char* writep) {
-    const char* const suffixp = m_suffixes.data() + code * VL_TRACE_SUFFIX_ENTRY_SIZE;
+void VerilatedVcdBuffer::finishLine(uint32_t code, char* writep) {
+    const char* const suffixp = m_suffixes + code * VL_TRACE_SUFFIX_ENTRY_SIZE;
+    VL_DEBUG_IFDEF(assert(suffixp[0]););
    VerilatedVcdCCopyAndAppendNewLine(writep, suffixp);

    // Now write back the write pointer incremented by the actual size of the
    // suffix, which was stored in the last byte of the suffix buffer entry.
    m_writep = writep + suffixp[VL_TRACE_SUFFIX_ENTRY_SIZE - 1];
-    bufferCheck();
+
+    if (m_owner.parallel()) {
+#ifdef VL_THREADED
+        // Double the size of the buffer if necessary
+        if (VL_UNLIKELY(m_writep >= m_growp)) {
+            // Compute occupied size of current buffer
+            const size_t usedSize = m_writep - m_bufp;
+            // We are always doubling the size
+            m_size *= 2;
+            // Allocate the new buffer
+            char* const newBufp = new char[m_size];
+            // Copy from current buffer to new buffer
+            std::memcpy(newBufp, m_bufp, usedSize);
+            // Delete current buffer
+            delete[] m_bufp;
+            // Make new buffer the current buffer
+            m_bufp = newBufp;
+            // Adjust write pointer
+            m_writep = m_bufp + usedSize;
+            // Adjust resize limit
+            adjustGrowp();
+        }
+#else
+        VL_FATAL_MT(__FILE__, __LINE__, "", "Unreachable");
+#endif
+    } else {
+        // Flush the write buffer if there's not enough space left for new information
+        // We only call this once per vector, so we need enough slop for a very wide "b###" line
+        if (VL_UNLIKELY(m_writep > m_wrFlushp)) {
+            m_owner.m_writep = m_writep;
+            m_owner.bufferFlush();
+            m_writep = m_owner.m_writep;
+        }
+    }
 }

 //=============================================================================
 // emit* trace routines

 // Note: emit* are only ever called from one place (full* in
-// verilated_trace_imp.cpp, which is included in this file at the top),
+// verilated_trace_imp.h, which is included in this file at the top),
 // so always inline them.

 VL_ATTR_ALWINLINE
-void VerilatedVcd::emitBit(vluint32_t code, CData newval) {
+void VerilatedVcdBuffer::emitBit(uint32_t code, CData newval) {
    // Don't prefetch suffix as it's a bit too late;
    char* wp = m_writep;
    *wp++ = '0' | static_cast<char>(newval);
@@ -630,7 +715,7 @@ void VerilatedVcd::emitBit(vluint32_t code, CData newval) {
 }

 VL_ATTR_ALWINLINE
-void VerilatedVcd::emitCData(vluint32_t code, CData newval, int bits) {
+void VerilatedVcdBuffer::emitCData(uint32_t code, CData newval, int bits) {
    char* wp = m_writep;
    *wp++ = 'b';
    cvtCDataToStr(wp, newval << (VL_BYTESIZE - bits));
@@ -638,7 +723,7 @@ void VerilatedVcd::emitCData(vluint32_t code, CData newval, int bits) {
 }

 VL_ATTR_ALWINLINE
-void VerilatedVcd::emitSData(vluint32_t code, SData newval, int bits) {
+void VerilatedVcdBuffer::emitSData(uint32_t code, SData newval, int bits) {
    char* wp = m_writep;
    *wp++ = 'b';
    cvtSDataToStr(wp, newval << (VL_SHORTSIZE - bits));
@@ -646,7 +731,7 @@ void VerilatedVcd::emitSData(vluint32_t code, SData newval, int bits) {
 }

 VL_ATTR_ALWINLINE
-void VerilatedVcd::emitIData(vluint32_t code, IData newval, int bits) {
+void VerilatedVcdBuffer::emitIData(uint32_t code, IData newval, int bits) {
    char* wp = m_writep;
    *wp++ = 'b';
    cvtIDataToStr(wp, newval << (VL_IDATASIZE - bits));
@@ -654,7 +739,7 @@ void VerilatedVcd::emitIData(vluint32_t code, IData newval, int bits) {
 }

 VL_ATTR_ALWINLINE
-void VerilatedVcd::emitQData(vluint32_t code, QData newval, int bits) {
+void VerilatedVcdBuffer::emitQData(uint32_t code, QData newval, int bits) {
    char* wp = m_writep;
    *wp++ = 'b';
    cvtQDataToStr(wp, newval << (VL_QUADSIZE - bits));
@@ -662,7 +747,7 @@ void VerilatedVcd::emitQData(vluint32_t code, QData newval, int bits) {
 }

 VL_ATTR_ALWINLINE
-void VerilatedVcd::emitWData(vluint32_t code, const WData* newvalp, int bits) {
+void VerilatedVcdBuffer::emitWData(uint32_t code, const WData* newvalp, int bits) {
    int words = VL_WORDS_I(bits);
    char* wp = m_writep;
    *wp++ = 'b';
@@ -679,272 +764,10 @@ void VerilatedVcd::emitWData(vluint32_t code, const WData* newvalp, int bits) {
 }

 VL_ATTR_ALWINLINE
-void VerilatedVcd::emitDouble(vluint32_t code, double newval) {
+void VerilatedVcdBuffer::emitDouble(uint32_t code, double newval) {
    char* wp = m_writep;
    // Buffer can't overflow before VL_SNPRINTF; we sized during declaration
-    VL_SNPRINTF(wp, m_wrChunkSize, "r%.16g", newval);
+    VL_SNPRINTF(wp, m_maxSignalBytes, "r%.16g", newval);
    wp += std::strlen(wp);
    finishLine(code, wp);
 }
-
-#ifdef VL_TRACE_VCD_OLD_API
-
-void VerilatedVcd::fullBit(vluint32_t code, const vluint32_t newval) {
-    // Note the &1, so we don't require clean input -- makes more common no change case faster
-    *oldp(code) = newval;
-    *m_writep++ = ('0' + static_cast<char>(newval & 1));
-    m_writep = writeCode(m_writep, code);
-    *m_writep++ = '\n';
-    bufferCheck();
-}
-void VerilatedVcd::fullBus(vluint32_t code, const vluint32_t newval, int bits) {
-    *oldp(code) = newval;
-    *m_writep++ = 'b';
-    for (int bit = bits - 1; bit >= 0; --bit) {
-        *m_writep++ = ((newval & (1L << bit)) ? '1' : '0');
-    }
-    *m_writep++ = ' ';
-    m_writep = writeCode(m_writep, code);
-    *m_writep++ = '\n';
-    bufferCheck();
-}
-void VerilatedVcd::fullQuad(vluint32_t code, const vluint64_t newval, int bits) {
-    (*(reinterpret_cast<vluint64_t*>(oldp(code)))) = newval;
-    *m_writep++ = 'b';
-    for (int bit = bits - 1; bit >= 0; --bit) {
-        *m_writep++ = ((newval & (1ULL << bit)) ? '1' : '0');
-    }
-    *m_writep++ = ' ';
-    m_writep = writeCode(m_writep, code);
-    *m_writep++ = '\n';
-    bufferCheck();
-}
-void VerilatedVcd::fullArray(vluint32_t code, const vluint32_t* newval, int bits) {
-    for (int word = 0; word < (((bits - 1) / 32) + 1); ++word) { oldp(code)[word] = newval[word]; }
-    *m_writep++ = 'b';
-    for (int bit = bits - 1; bit >= 0; --bit) {
-        *m_writep++ = ((newval[(bit / 32)] & (1L << (bit & 0x1f))) ? '1' : '0');
-    }
-    *m_writep++ = ' ';
-    m_writep = writeCode(m_writep, code);
-    *m_writep++ = '\n';
-    bufferCheck();
-}
-void VerilatedVcd::fullArray(vluint32_t code, const vluint64_t* newval, int bits) {
-    for (int word = 0; word < (((bits - 1) / 64) + 1); ++word) { oldp(code)[word] = newval[word]; }
-    *m_writep++ = 'b';
-    for (int bit = bits - 1; bit >= 0; --bit) {
-        *m_writep++ = ((newval[(bit / 64)] & (1ULL << (bit & 0x3f))) ? '1' : '0');
-    }
-    *m_writep++ = ' ';
-    m_writep = writeCode(m_writep, code);
-    *m_writep++ = '\n';
-    bufferCheck();
-}
-void VerilatedVcd::fullTriBit(vluint32_t code, const vluint32_t newval, const vluint32_t newtri) {
-    oldp(code)[0] = newval;
-    oldp(code)[1] = newtri;
-    *m_writep++ = "01zz"[newval | (newtri << 1)];
-    m_writep = writeCode(m_writep, code);
-    *m_writep++ = '\n';
-    bufferCheck();
-}
-void VerilatedVcd::fullTriBus(vluint32_t code, const vluint32_t newval, const vluint32_t newtri,
-                              int bits) {
-    oldp(code)[0] = newval;
-    oldp(code)[1] = newtri;
-    *m_writep++ = 'b';
-    for (int bit = bits - 1; bit >= 0; --bit) {
-        *m_writep++ = "01zz"[((newval >> bit) & 1) | (((newtri >> bit) & 1) << 1)];
-    }
-    *m_writep++ = ' ';
-    m_writep = writeCode(m_writep, code);
-    *m_writep++ = '\n';
-    bufferCheck();
-}
-void VerilatedVcd::fullTriQuad(vluint32_t code, const vluint64_t newval, const vluint64_t newtri,
-                               int bits) {
-    (*(reinterpret_cast<vluint64_t*>(oldp(code)))) = newval;
-    (*(reinterpret_cast<vluint64_t*>(oldp(code + 1)))) = newtri;
-    *m_writep++ = 'b';
-    for (int bit = bits - 1; bit >= 0; --bit) {
-        *m_writep++ = "01zz"[((newval >> bit) & 1ULL) | (((newtri >> bit) & 1ULL) << 1ULL)];
-    }
-    *m_writep++ = ' ';
-    m_writep = writeCode(m_writep, code);
-    *m_writep++ = '\n';
-    bufferCheck();
-}
-void VerilatedVcd::fullTriArray(vluint32_t code, const vluint32_t* newvalp,
-                                const vluint32_t* newtrip, int bits) {
-    for (int word = 0; word < (((bits - 1) / 32) + 1); ++word) {
-        oldp(code)[word * 2] = newvalp[word];
-        oldp(code)[word * 2 + 1] = newtrip[word];
-    }
-    *m_writep++ = 'b';
-    for (int bit = bits - 1; bit >= 0; --bit) {
-        vluint32_t valbit = (newvalp[(bit / 32)] >> (bit & 0x1f)) & 1;
-        vluint32_t tribit = (newtrip[(bit / 32)] >> (bit & 0x1f)) & 1;
-        *m_writep++ = "01zz"[valbit | (tribit << 1)];
-    }
-    *m_writep++ = ' ';
-    m_writep = writeCode(m_writep, code);
-    *m_writep++ = '\n';
-    bufferCheck();
-}
-void VerilatedVcd::fullDouble(vluint32_t code, const double newval) {
-    // cppcheck-suppress invalidPointerCast
-    (*(reinterpret_cast<double*>(oldp(code)))) = newval;
-    // Buffer can't overflow before VL_SNPRINTF; we sized during declaration
-    VL_SNPRINTF(m_writep, m_wrChunkSize, "r%.16g", newval);
-    m_writep += std::strlen(m_writep);
-    *m_writep++ = ' ';
-    m_writep = writeCode(m_writep, code);
-    *m_writep++ = '\n';
-    bufferCheck();
-}
-
-#endif  // VL_TRACE_VCD_OLD_API
-
-//======================================================================
-//======================================================================
-//======================================================================
-
-#ifdef VERILATED_VCD_TEST
-#include <iostream>
-
-extern void verilated_trace_imp_selftest();
-
-vluint32_t v1, v2, s1, s2[3];
-vluint32_t tri96[3];
-vluint32_t tri96__tri[3];
-vluint64_t quad96[2];
-vluint64_t tquad;
-vluint64_t tquad__tri;
-vluint8_t ch;
-vluint64_t timestamp = 1;
-double doub = 0.0;
-float flo = 0.0f;
-
-void vcdInit(void*, VerilatedVcd* vcdp, vluint32_t) {
-    vcdp->scopeEscape('.');
-    vcdp->pushNamePrefix("top.");
-    /**/ vcdp->declBus(0x2, "v1", -1, 0, 5, 1);
-    /**/ vcdp->declBus(0x3, "v2", -1, 0, 6, 1);
-    /**/ vcdp->pushNamePrefix("sub1.");
-    /***/ vcdp->declBit(0x4, "s1", -1, 0);
-    /***/ vcdp->declBit(0x5, "ch", -1, 0);
-    /**/ vcdp->popNamePrefix();
-    /**/ vcdp->pushNamePrefix("sub2.");
-    /***/ vcdp->declArray(0x6, "s2", -1, 0, 40, 3);
-    /**/ vcdp->popNamePrefix();
-    vcdp->popNamePrefix();
-    // Note need to add 3 for next code.
-    vcdp->pushNamePrefix("top2.");
-    /**/ vcdp->declBus(0x2, "t2v1", -1, 0, 4, 1);
-    /**/ vcdp->declTriBit(0x10, "io1", -1, 0);
-    /**/ vcdp->declTriBus(0x12, "io5", -1, 0, 4, 0);
-    /**/ vcdp->declTriArray(0x16, "io96", -1, 0, 95, 0);
-    /**/  // Note need to add 6 for next code.
-    /**/ vcdp->declDouble(0x1c, "doub", -1, 0);
-    /**/  // Note need to add 2 for next code.
-    /**/ vcdp->declArray(0x20, "q2", -1, 0, 95, 0);
-    /**/  // Note need to add 4 for next code.
-    /**/ vcdp->declTriQuad(0x24, "tq", -1, 0, 63, 0);
-    /**/  // Note need to add 4 for next code.
-    vcdp->popNamePrefix();
-}
-
-void vcdFull(void*, VerilatedVcd* vcdp) {
-    vcdp->fullBus(0x2, v1, 5);
-    vcdp->fullBus(0x3, v2, 7);
-    vcdp->fullBit(0x4, s1);
-    vcdp->fullBus(0x5, ch, 2);
-    vcdp->fullArray(0x6, &s2[0], 38);
-    vcdp->fullTriBit(0x10, tri96[0] & 1, tri96__tri[0] & 1);
-    vcdp->fullTriBus(0x12, tri96[0] & 0x1f, tri96__tri[0] & 0x1f, 5);
-    vcdp->fullTriArray(0x16, tri96, tri96__tri, 96);
-    vcdp->fullDouble(0x1c, doub);
-    vcdp->fullArray(0x20, &quad96[0], 96);
-    vcdp->fullTriQuad(0x24, tquad, tquad__tri, 64);
-}
-
-void vcdChange(void*, VerilatedVcd* vcdp) {
-    vcdp->chgBus(0x2, v1, 5);
-    vcdp->chgBus(0x3, v2, 7);
-    vcdp->chgBit(0x4, s1);
-    vcdp->chgBus(0x5, ch, 2);
-    vcdp->chgArray(0x6, &s2[0], 38);
-    vcdp->chgTriBit(0x10, tri96[0] & 1, tri96__tri[0] & 1);
-    vcdp->chgTriBus(0x12, tri96[0] & 0x1f, tri96__tri[0] & 0x1f, 5);
-    vcdp->chgTriArray(0x16, tri96, tri96__tri, 96);
-    vcdp->chgDouble(0x1c, doub);
-    vcdp->chgArray(0x20, &quad96[0], 96);
-    vcdp->chgTriQuad(0x24, tquad, tquad__tri, 64);
-}
-
-// clang-format off
-void vcdTestMain(const char* filenamep) {
-    verilated_trace_imp_selftest();
-
-    v1 = v2 = s1 = 0;
-    s2[0] = s2[1] = s2[2] = 0;
-    tri96[2] = tri96[1] = tri96[0] = 0;
-    tri96__tri[2] = tri96__tri[1] = tri96__tri[0] = ~0;
-    quad96[1] = quad96[0] = 0;
-    ch = 0;
-    doub = 0;
-    tquad = tquad__tri = 0;
-    {
-        VerilatedVcdC* vcdp = new VerilatedVcdC;
-        vcdp->evcd(true);
-        vcdp->set_time_unit("1ms");
-        vcdp->set_time_unit(std::string{"1ms"});
-        vcdp->set_time_resolution("1ns");
-        vcdp->set_time_resolution(std::string{"1ns"});
-        vcdp->spTrace()->addInitCb(&vcdInit, 0);
-        vcdp->spTrace()->addFullCb(&vcdFull, 0);
-        vcdp->spTrace()->addChgCb(&vcdChange, 0);
-        vcdp->open(filenamep);
-        // Dumping
-        vcdp->dump(++timestamp);
-        v1 = 0xfff;
-        tri96[2] = 4; tri96[1] = 2; tri96[0] = 1;
-        tri96__tri[2] = tri96__tri[1] = tri96__tri[0] = ~0;  // Still tri
-        quad96[1] = 0xffffffff; quad96[0] = 0;
-        doub = 1.5;
-        flo = 1.4f;
-        vcdp->dump(++timestamp);
-        v2 = 0x1;
-        s2[1] = 2;
-        tri96__tri[2] = tri96__tri[1] = tri96__tri[0] = 0;  // enable w/o data change
-        quad96[1] = 0; quad96[0] = ~0;
-        doub = -1.66e13;
-        flo = 0.123f;
-        tquad = 0x00ff00ff00ff00ffULL;
-        tquad__tri = 0x0000fffff0000ffffULL;
-        vcdp->dump(++timestamp);
-        ch = 2;
-        tri96[2] = ~4; tri96[1] = ~2; tri96[0] = ~1;
-        doub = -3.33e-13;
-        vcdp->dump(++timestamp);
-        vcdp->dump(++timestamp);
-# ifdef VERILATED_VCD_TEST_64BIT
-        const vluint64_t bytesPerDump = 15ULL;
-        for (vluint64_t i = 0; i < ((1ULL << 32) / bytesPerDump); i++) {
-            v1 = i;
-            vcdp->dump(++timestamp);
-        }
-# endif
-        vcdp->close();
-        VL_DO_CLEAR(delete vcdp, vcdp = nullptr);
-    }
-}
-#endif
-// clang-format on
-
-//********************************************************************
-// ;compile-command: "v4make test_regress/t/t_trace_c_api.pl"
-//
-// Local Variables:
-// End:
@@ -28,7 +28,196 @@
 #include <string>
 #include <vector>

-class VerilatedVcd;
+class VerilatedVcdBuffer;
+class VerilatedVcdFile;
+
+//=============================================================================
+// VerilatedVcd
+// Base class to create a Verilator VCD dump
+// This is an internally used class - see VerilatedVcdC for what to call from applications
+
+class VerilatedVcd VL_NOT_FINAL : public VerilatedTrace<VerilatedVcd, VerilatedVcdBuffer> {
+public:
+    using Super = VerilatedTrace<VerilatedVcd, VerilatedVcdBuffer>;
+
+private:
+    friend VerilatedVcdBuffer;  // Give the buffer access to the private bits
+
+    //=========================================================================
+    // VCD specific internals
+
+    VerilatedVcdFile* m_filep;  // File we're writing to
+    bool m_fileNewed;  // m_filep needs destruction
+    bool m_isOpen = false;  // True indicates open file
+    std::string m_filename;  // Filename we're writing to (if open)
+    uint64_t m_rolloverSize = 0;  // File size to rollover at
+    int m_modDepth = 0;  // Depth of module hierarchy
+
+    char* m_wrBufp;  // Output buffer
+    char* m_wrFlushp;  // Output buffer flush trigger location
+    char* m_writep;  // Write pointer into output buffer
+    size_t m_wrChunkSize;  // Output buffer size
+    size_t m_maxSignalBytes = 0;  // Upper bound on number of bytes a single signal can generate
+    uint64_t m_wroteBytes = 0;  // Number of bytes written to this file
+
+    std::vector<char> m_suffixes;  // VCD line end string codes + metadata
+
+    using NameMap = std::map<const std::string, const std::string>;
+    NameMap* m_namemapp = nullptr;  // List of names for the header
+
+#ifdef VL_THREADED
+    // Vector of free trace buffers as (pointer, size) pairs.
+    std::vector<std::pair<char*, size_t>> m_freeBuffers;
+    size_t m_numBuffers = 0;  // Number of trace buffers allocated
+#endif
+
+    void bufferResize(size_t minsize);
+    void bufferFlush() VL_MT_UNSAFE_ONE;
+    void bufferCheck() {
+        // Flush the write buffer if there's not enough space left for new information
+        // We only call this once per vector, so we need enough slop for a very wide "b###" line
+        if (VL_UNLIKELY(m_writep > m_wrFlushp)) bufferFlush();
+    }
+    void openNextImp(bool incFilename);
+    void closePrev();
+    void closeErr();
+    void makeNameMap();
+    void deleteNameMap();
+    void printIndent(int level_change);
+    void printStr(const char* str);
+    void printQuad(uint64_t n);
+    void printTime(uint64_t timeui);
+    void declare(uint32_t code, const char* name, const char* wirep, bool array, int arraynum,
+                 bool tri, bool bussed, int msb, int lsb);
+
+    void dumpHeader();
+
+    static char* writeCode(char* writep, uint32_t code);
+
+    // CONSTRUCTORS
+    VL_UNCOPYABLE(VerilatedVcd);
+
+protected:
+    //=========================================================================
+    // Implementation of VerilatedTrace interface
+
+    // Called when the trace moves forward to a new time point
+    void emitTimeChange(uint64_t timeui) override;
+
+    // Hooks called from VerilatedTrace
+    bool preFullDump() override { return isOpen(); }
+    bool preChangeDump() override;
+
+    // Trace buffer management
+    Buffer* getTraceBuffer() override;
+    void commitTraceBuffer(Buffer*) override;
+
+    // Configure sub-class
+    void configure(const VerilatedTraceConfig&) override{};
+
+public:
+    //=========================================================================
+    // External interface to client code
+
+    // CONSTRUCTOR
+    explicit VerilatedVcd(VerilatedVcdFile* filep = nullptr);
+    ~VerilatedVcd();
+
+    // ACCESSORS
+    // Set size in bytes after which new file should be created.
+    void rolloverSize(uint64_t size) { m_rolloverSize = size; }
+
+    // METHODS - All must be thread safe
+    // Open the file; call isOpen() to see if errors
+    void open(const char* filename) VL_MT_SAFE_EXCLUDES(m_mutex);
+    // Open next data-only file
+    void openNext(bool incFilename) VL_MT_SAFE_EXCLUDES(m_mutex);
+    // Close the file
+    void close() VL_MT_SAFE_EXCLUDES(m_mutex);
+    // Flush any remaining data to this file
+    void flush() VL_MT_SAFE_EXCLUDES(m_mutex);
+    // Return if file is open
+    bool isOpen() const VL_MT_SAFE { return m_isOpen; }
+
+    //=========================================================================
+    // Internal interface to Verilator generated code
+
+    void declBit(uint32_t code, const char* name, bool array, int arraynum);
+    void declBus(uint32_t code, const char* name, bool array, int arraynum, int msb, int lsb);
+    void declQuad(uint32_t code, const char* name, bool array, int arraynum, int msb, int lsb);
+    void declArray(uint32_t code, const char* name, bool array, int arraynum, int msb, int lsb);
+    void declDouble(uint32_t code, const char* name, bool array, int arraynum);
+};
+
+#ifndef DOXYGEN
+// Declare specialization here as it's used in VerilatedFstC just below
+template <>
+void VerilatedVcd::Super::dump(uint64_t time);
+template <>
+void VerilatedVcd::Super::set_time_unit(const char* unitp);
+template <>
+void VerilatedVcd::Super::set_time_unit(const std::string& unit);
+template <>
+void VerilatedVcd::Super::set_time_resolution(const char* unitp);
+template <>
+void VerilatedVcd::Super::set_time_resolution(const std::string& unit);
+template <>
+void VerilatedVcd::Super::dumpvars(int level, const std::string& hier);
+#endif  // DOXYGEN
+
+//=============================================================================
+// VerilatedVcdBuffer
+
+class VerilatedVcdBuffer VL_NOT_FINAL {
+    // Give the trace file ans sub-classes access to the private bits
+    friend VerilatedVcd;
+    friend VerilatedVcd::Super;
+    friend VerilatedVcd::Buffer;
+    friend VerilatedVcd::OffloadBuffer;
+
+    VerilatedVcd& m_owner;  // Trace file owning this buffer. Required by subclasses.
+
+    // Write pointer into output buffer (in parallel mode, this is set up in 'getTraceBuffer')
+    char* m_writep = m_owner.parallel() ? nullptr : m_owner.m_writep;
+    // Output buffer flush trigger location (only used when not parallel)
+    char* const m_wrFlushp = m_owner.parallel() ? nullptr : m_owner.m_wrFlushp;
+
+    // VCD line end string codes + metadata
+    const char* const m_suffixes = m_owner.m_suffixes.data();
+    // The maximum number of bytes a single signal can emit
+    const size_t m_maxSignalBytes = m_owner.m_maxSignalBytes;
+
+#ifdef VL_THREADED
+    // Additional data for parallel tracing only
+    char* m_bufp = nullptr;  // The beginning of the trace buffer
+    size_t m_size = 0;  // The size of the buffer at m_bufp
+    char* m_growp = nullptr;  // Resize limit pointer
+
+    void adjustGrowp() {
+        m_growp = (m_bufp + m_size) - (2 * m_maxSignalBytes);
+        assert(m_growp >= m_bufp + m_maxSignalBytes);
+    }
+#endif
+
+    void finishLine(uint32_t code, char* writep);
+
+    // CONSTRUCTOR
+    explicit VerilatedVcdBuffer(VerilatedVcd& owner)
+        : m_owner{owner} {}
+    virtual ~VerilatedVcdBuffer() = default;
+
+    //=========================================================================
+    // Implementation of VerilatedTraceBuffer interface
+    // Implementations of duck-typed methods for VerilatedTraceBuffer. These are
+    // called from only one place (the full* methods), so always inline them.
+    VL_ATTR_ALWINLINE void emitBit(uint32_t code, CData newval);
+    VL_ATTR_ALWINLINE void emitCData(uint32_t code, CData newval, int bits);
+    VL_ATTR_ALWINLINE void emitSData(uint32_t code, SData newval, int bits);
+    VL_ATTR_ALWINLINE void emitIData(uint32_t code, IData newval, int bits);
+    VL_ATTR_ALWINLINE void emitQData(uint32_t code, QData newval, int bits);
+    VL_ATTR_ALWINLINE void emitWData(uint32_t code, const WData* newvalp, int bits);
+    VL_ATTR_ALWINLINE void emitDouble(uint32_t code, double newval);
+};

 //=============================================================================
 // VerilatedFile
@@ -52,284 +241,6 @@ public:
    virtual ssize_t write(const char* bufp, ssize_t len) VL_MT_UNSAFE;
 };

-//=============================================================================
-// VerilatedVcd
-// Base class to create a Verilator VCD dump
-// This is an internally used class - see VerilatedVcdC for what to call from applications
-
-class VerilatedVcd VL_NOT_FINAL : public VerilatedTrace<VerilatedVcd> {
-private:
-    // Give the superclass access to private bits (to avoid virtual functions)
-    friend class VerilatedTrace<VerilatedVcd>;
-
-    //=========================================================================
-    // VCD specific internals
-
-    VerilatedVcdFile* m_filep;  // File we're writing to
-    bool m_fileNewed;  // m_filep needs destruction
-    bool m_isOpen = false;  // True indicates open file
-    bool m_evcd = false;  // True for evcd format
-    std::string m_filename;  // Filename we're writing to (if open)
-    vluint64_t m_rolloverMB = 0;  // MB of file size to rollover at
-    int m_modDepth = 0;  // Depth of module hierarchy
-
-    char* m_wrBufp;  // Output buffer
-    const char* m_wrFlushp;  // Output buffer flush trigger location
-    char* m_writep;  // Write pointer into output buffer
-    vluint64_t m_wrChunkSize;  // Output buffer size
-    vluint64_t m_wroteBytes = 0;  // Number of bytes written to this file
-
-    std::vector<char> m_suffixes;  // VCD line end string codes + metadata
-
-    using NameMap = std::map<const std::string, const std::string>;
-    NameMap* m_namemapp = nullptr;  // List of names for the header
-
-    void bufferResize(vluint64_t minsize);
-    void bufferFlush() VL_MT_UNSAFE_ONE;
-    inline void bufferCheck() {
-        // Flush the write buffer if there's not enough space left for new information
-        // We only call this once per vector, so we need enough slop for a very wide "b###" line
-        if (VL_UNLIKELY(m_writep > m_wrFlushp)) bufferFlush();
-    }
-    void openNextImp(bool incFilename);
-    void closePrev();
-    void closeErr();
-    void makeNameMap();
-    void deleteNameMap();
-    void printIndent(int level_change);
-    void printStr(const char* str);
-    void printQuad(vluint64_t n);
-    void printTime(vluint64_t timeui);
-    void declare(vluint32_t code, const char* name, const char* wirep, bool array, int arraynum,
-                 bool tri, bool bussed, int msb, int lsb);
-
-    void dumpHeader();
-
-    static char* writeCode(char* writep, vluint32_t code);
-
-    void finishLine(vluint32_t code, char* writep);
-
-    // CONSTRUCTORS
-    VL_UNCOPYABLE(VerilatedVcd);
-
-protected:
-    //=========================================================================
-    // Implementation of VerilatedTrace interface
-
-    // Implementations of protected virtual methods for VerilatedTrace
-    virtual void emitTimeChange(vluint64_t timeui) override;
-
-    // Hooks called from VerilatedTrace
-    virtual bool preFullDump() override { return isOpen(); }
-    virtual bool preChangeDump() override;
-
-    // Implementations of duck-typed methods for VerilatedTrace. These are
-    // called from only one place (namely full*) so always inline them.
-    inline void emitBit(vluint32_t code, CData newval);
-    inline void emitCData(vluint32_t code, CData newval, int bits);
-    inline void emitSData(vluint32_t code, SData newval, int bits);
-    inline void emitIData(vluint32_t code, IData newval, int bits);
-    inline void emitQData(vluint32_t code, QData newval, int bits);
-    inline void emitWData(vluint32_t code, const WData* newvalp, int bits);
-    inline void emitDouble(vluint32_t code, double newval);
-
-public:
-    //=========================================================================
-    // External interface to client code
-
-    explicit VerilatedVcd(VerilatedVcdFile* filep = nullptr);
-    ~VerilatedVcd();
-
-    // ACCESSORS
-    // Set size in megabytes after which new file should be created
-    void rolloverMB(vluint64_t rolloverMB) { m_rolloverMB = rolloverMB; }
-
-    // METHODS
-    // Open the file; call isOpen() to see if errors
-    void open(const char* filename) VL_MT_SAFE_EXCLUDES(m_mutex);
-    // Open next data-only file
-    void openNext(bool incFilename) VL_MT_SAFE_EXCLUDES(m_mutex);
-    // Close the file
-    void close() VL_MT_SAFE_EXCLUDES(m_mutex);
-    // Flush any remaining data to this file
-    void flush() VL_MT_SAFE_EXCLUDES(m_mutex);
-    // Return if file is open
-    bool isOpen() const VL_MT_SAFE { return m_isOpen; }
-
-    //=========================================================================
-    // Internal interface to Verilator generated code
-
-    void declBit(vluint32_t code, const char* name, bool array, int arraynum);
-    void declBus(vluint32_t code, const char* name, bool array, int arraynum, int msb, int lsb);
-    void declQuad(vluint32_t code, const char* name, bool array, int arraynum, int msb, int lsb);
-    void declArray(vluint32_t code, const char* name, bool array, int arraynum, int msb, int lsb);
-    void declDouble(vluint32_t code, const char* name, bool array, int arraynum);
-
-#ifdef VL_TRACE_VCD_OLD_API
-    //=========================================================================
-    // Note: These are only for testing for backward compatibility with foreign
-    // code and is not used by Verilator. Do not use these as there is no
-    // guarantee of functionality.
-
-    void declTriBit(vluint32_t code, const char* name, bool array, int arraynum);
-    void declTriBus(vluint32_t code, const char* name, bool array, int arraynum, int msb, int lsb);
-    void declTriQuad(vluint32_t code, const char* name, bool array, int arraynum, int msb,
-                     int lsb);
-    void declTriArray(vluint32_t code, const char* name, bool array, int arraynum, int msb,
-                      int lsb);
-
-    void fullBit(vluint32_t* oldp, CData newval) { fullBit(oldp - this->oldp(0), newval); }
-    void fullCData(vluint32_t* oldp, CData newval, int bits) {
-        fullBus(oldp - this->oldp(0), newval, bits);
-    }
-    void fullSData(vluint32_t* oldp, SData newval, int bits) {
-        fullBus(oldp - this->oldp(0), newval, bits);
-    }
-    void fullIData(vluint32_t* oldp, IData newval, int bits) {
-        fullBus(oldp - this->oldp(0), newval, bits);
-    }
-    void fullQData(vluint32_t* oldp, QData newval, int bits) {
-        fullQuad(oldp - this->oldp(0), newval, bits);
-    }
-    void fullWData(vluint32_t* oldp, const WData* newvalp, int bits) {
-        fullArray(oldp - this->oldp(0), newvalp, bits);
-    }
-    void fullDouble(vluint32_t* oldp, double newval) { fullDouble(oldp - this->oldp(0), newval); }
-
-    inline void chgBit(vluint32_t* oldp, CData newval) { chgBit(oldp - this->oldp(0), newval); }
-    inline void chgCData(vluint32_t* oldp, CData newval, int bits) {
-        chgBus(oldp - this->oldp(0), newval, bits);
-    }
-    inline void chgSData(vluint32_t* oldp, SData newval, int bits) {
-        chgBus(oldp - this->oldp(0), newval, bits);
-    }
-    inline void chgIData(vluint32_t* oldp, IData newval, int bits) {
-        chgBus(oldp - this->oldp(0), newval, bits);
-    }
-    inline void chgQData(vluint32_t* oldp, QData newval, int bits) {
-        chgQuad(oldp - this->oldp(0), newval, bits);
-    }
-    inline void chgWData(vluint32_t* oldp, const WData* newvalp, int bits) {
-        chgArray(oldp - this->oldp(0), newvalp, bits);
-    }
-    inline void chgDouble(vluint32_t* oldp, double newval) {
-        chgDouble(oldp - this->oldp(0), newval);
-    }
-
-    // Inside dumping routines, dump one signal, faster when not inlined
-    // due to code size reduction.
-    void fullBit(vluint32_t code, const vluint32_t newval);
-    void fullBus(vluint32_t code, const vluint32_t newval, int bits);
-    void fullQuad(vluint32_t code, const vluint64_t newval, int bits);
-    void fullArray(vluint32_t code, const vluint32_t* newvalp, int bits);
-    void fullArray(vluint32_t code, const vluint64_t* newvalp, int bits);
-    void fullTriBit(vluint32_t code, const vluint32_t newval, const vluint32_t newtri);
-    void fullTriBus(vluint32_t code, const vluint32_t newval, const vluint32_t newtri, int bits);
-    void fullTriQuad(vluint32_t code, const vluint64_t newval, const vluint64_t newtri, int bits);
-    void fullTriArray(vluint32_t code, const vluint32_t* newvalp, const vluint32_t* newtrip,
-                      int bits);
-    void fullDouble(vluint32_t code, const double newval);
-
-    // Inside dumping routines, dump one signal if it has changed.
-    // We do want to inline these to avoid calls when the value did not change.
-    inline void chgBit(vluint32_t code, const vluint32_t newval) {
-        const vluint32_t diff = oldp(code)[0] ^ newval;
-        if (VL_UNLIKELY(diff)) fullBit(code, newval);
-    }
-    inline void chgBus(vluint32_t code, const vluint32_t newval, int bits) {
-        const vluint32_t diff = oldp(code)[0] ^ newval;
-        if (VL_UNLIKELY(diff)) {
-            if (VL_UNLIKELY(bits == 32 || (diff & ((1U << bits) - 1)))) {
-                fullBus(code, newval, bits);
-            }
-        }
-    }
-    inline void chgQuad(vluint32_t code, const vluint64_t newval, int bits) {
-        const vluint64_t diff = (*(reinterpret_cast<vluint64_t*>(oldp(code)))) ^ newval;
-        if (VL_UNLIKELY(diff)) {
-            if (VL_UNLIKELY(bits == 64 || (diff & ((1ULL << bits) - 1)))) {
-                fullQuad(code, newval, bits);
-            }
-        }
-    }
-    inline void chgArray(vluint32_t code, const vluint32_t* newvalp, int bits) {
-        for (int word = 0; word < (((bits - 1) / 32) + 1); ++word) {
-            if (VL_UNLIKELY(oldp(code)[word] ^ newvalp[word])) {
-                fullArray(code, newvalp, bits);
-                return;
-            }
-        }
-    }
-    inline void chgArray(vluint32_t code, const vluint64_t* newvalp, int bits) {
-        for (int word = 0; word < (((bits - 1) / 64) + 1); ++word) {
-            if (VL_UNLIKELY(*(reinterpret_cast<vluint64_t*>(oldp(code + 2 * word)))
-                            ^ newvalp[word])) {
-                fullArray(code, newvalp, bits);
-                return;
-            }
-        }
-    }
-    inline void chgTriBit(vluint32_t code, const vluint32_t newval, const vluint32_t newtri) {
-        const vluint32_t diff = ((oldp(code)[0] ^ newval) | (oldp(code)[1] ^ newtri));
-        if (VL_UNLIKELY(diff)) {
-            // Verilator 3.510 and newer provide clean input, so the below
-            // is only for back compatibility
-            if (VL_UNLIKELY(diff & 1)) {  // Change after clean?
-                fullTriBit(code, newval, newtri);
-            }
-        }
-    }
-    inline void chgTriBus(vluint32_t code, const vluint32_t newval, const vluint32_t newtri,
-                          int bits) {
-        const vluint32_t diff = ((oldp(code)[0] ^ newval) | (oldp(code)[1] ^ newtri));
-        if (VL_UNLIKELY(diff)) {
-            if (VL_UNLIKELY(bits == 32 || (diff & ((1U << bits) - 1)))) {
-                fullTriBus(code, newval, newtri, bits);
-            }
-        }
-    }
-    inline void chgTriQuad(vluint32_t code, const vluint64_t newval, const vluint64_t newtri,
-                           int bits) {
-        const vluint64_t diff = (((*(reinterpret_cast<vluint64_t*>(oldp(code)))) ^ newval)
-                                 | ((*(reinterpret_cast<vluint64_t*>(oldp(code + 1)))) ^ newtri));
-        if (VL_UNLIKELY(diff)) {
-            if (VL_UNLIKELY(bits == 64 || (diff & ((1ULL << bits) - 1)))) {
-                fullTriQuad(code, newval, newtri, bits);
-            }
-        }
-    }
-    inline void chgTriArray(vluint32_t code, const vluint32_t* newvalp, const vluint32_t* newtrip,
-                            int bits) {
-        for (int word = 0; word < (((bits - 1) / 32) + 1); ++word) {
-            if (VL_UNLIKELY((oldp(code)[word * 2] ^ newvalp[word])
-                            | (oldp(code)[word * 2 + 1] ^ newtrip[word]))) {
-                fullTriArray(code, newvalp, newtrip, bits);
-                return;
-            }
-        }
-    }
-    inline void chgDouble(vluint32_t code, const double newval) {
-        // cppcheck-suppress invalidPointerCast
-        if (VL_UNLIKELY((*(reinterpret_cast<double*>(oldp(code)))) != newval)) {
-            fullDouble(code, newval);
-        }
-    }
-
-    // METHODS
-    // Old/standalone API only
-    void evcd(bool flag) { m_evcd = flag; }
-#endif  // VL_TRACE_VCD_OLD_API
-};
-
-#ifndef DOXYGEN
-// Declare specializations here they are used in VerilatedVcdC just below
-template <> void VerilatedTrace<VerilatedVcd>::dump(vluint64_t timeui);
-template <> void VerilatedTrace<VerilatedVcd>::set_time_unit(const char* unitp);
-template <> void VerilatedTrace<VerilatedVcd>::set_time_unit(const std::string& unit);
-template <> void VerilatedTrace<VerilatedVcd>::set_time_resolution(const char* unitp);
-template <> void VerilatedTrace<VerilatedVcd>::set_time_resolution(const std::string& unit);
-#endif  // DOXYGEN
-
 //=============================================================================
 // VerilatedVcdC
 /// Class representing a VCD dump file in C standalone (no SystemC)
@@ -348,7 +259,6 @@ public:
    /// Destruct, flush, and close the dump
    virtual ~VerilatedVcdC() { close(); }

-public:
    // METHODS - User called

    /// Return if file is open
@@ -361,8 +271,12 @@ public:
    /// The header is only in the first file created, this allows
    /// "cat" to be used to combine the header plus any number of data files.
    void openNext(bool incFilename = true) VL_MT_SAFE { m_sptrace.openNext(incFilename); }
-    /// Set size in megabytes after which new file should be created
-    void rolloverMB(size_t rolloverMB) VL_MT_SAFE { m_sptrace.rolloverMB(rolloverMB); }
+    /// Set size in bytes after which new file should be created
+    /// This will create a header file, followed by each separate file
+    /// which might be larger than the given size (due to chunking and
+    /// alignment to a start of a given time's dump).  Any file but the
+    /// first may be removed.  Cat files together to create viewable vcd.
+    void rolloverSize(size_t size) VL_MT_SAFE { m_sptrace.rolloverSize(size); }
    /// Close dump
    void close() VL_MT_SAFE { m_sptrace.close(); }
    /// Flush dump
@@ -370,12 +284,12 @@ public:
    /// Write one cycle of dump data
    /// Call with the current context's time just after eval'ed,
    /// e.g. ->dump(contextp->time())
-    void dump(vluint64_t timeui) VL_MT_SAFE { m_sptrace.dump(timeui); }
+    void dump(uint64_t timeui) VL_MT_SAFE { m_sptrace.dump(timeui); }
    /// Write one cycle of dump data - backward compatible and to reduce
-    /// conversion warnings.  It's better to use a vluint64_t time instead.
-    void dump(double timestamp) { dump(static_cast<vluint64_t>(timestamp)); }
-    void dump(vluint32_t timestamp) { dump(static_cast<vluint64_t>(timestamp)); }
-    void dump(int timestamp) { dump(static_cast<vluint64_t>(timestamp)); }
+    /// conversion warnings.  It's better to use a uint64_t time instead.
+    void dump(double timestamp) { dump(static_cast<uint64_t>(timestamp)); }
+    void dump(uint32_t timestamp) { dump(static_cast<uint64_t>(timestamp)); }
+    void dump(int timestamp) { dump(static_cast<uint64_t>(timestamp)); }

    // METHODS - Internal/backward compatible
    // \protectedsection
@@ -392,19 +306,14 @@ public:
    void set_time_resolution(const std::string& unit) VL_MT_SAFE {
        m_sptrace.set_time_resolution(unit);
    }
+    // Set variables to dump, using $dumpvars format
+    // If level = 0, dump everything and hier is then ignored
+    void dumpvars(int level, const std::string& hier) VL_MT_SAFE {
+        m_sptrace.dumpvars(level, hier);
+    }

    // Internal class access
-    inline VerilatedVcd* spTrace() { return &m_sptrace; }
-
-#ifdef VL_TRACE_VCD_OLD_API
-    //=========================================================================
-    // Note: These are only for testing for backward compatibility with foreign
-    // code and is not used by Verilator. Do not use these as there is no
-    // guarantee of functionality.
-
-    // Use evcd format
-    void evcd(bool flag) VL_MT_UNSAFE_ONE { m_sptrace.evcd(flag); }
-#endif
+    VerilatedVcd* spTrace() { return &m_sptrace; }
 };

 #endif  // guard
@@ -22,6 +22,7 @@
 //=============================================================================

 #include "verilatedos.h"
+
 #include "verilated_vcd_sc.h"

 //======================================================================
@@ -30,7 +31,7 @@
 void VerilatedVcdSc::open(const char* filename) {
    if (!sc_core::sc_get_curr_simcontext()->elaboration_done()) {
        vl_fatal(__FILE__, __LINE__, "VerilatedVcdSc",
-                 ("%Error: VerilatedVcdSc::open(\"" + std::string(filename)
+                 ("%Error: VerilatedVcdSc::open(\"" + std::string{filename}
                  + "\") is called before sc_core::sc_start(). "
                    "Run sc_core::sc_start(sc_core::SC_ZERO_TIME) before opening a wave file.")
                     .c_str());
@@ -63,9 +64,6 @@ void VerilatedVcdSc::trace(const unsigned int&, const std::string&, const char**
    DECL_TRACE_METHOD_B( unsigned short )
    DECL_TRACE_METHOD_B( unsigned int )
    DECL_TRACE_METHOD_B( unsigned long )
-#ifdef SYSTEMC_64BIT_PATCHES
-    DECL_TRACE_METHOD_B( unsigned long long)
-#endif
    DECL_TRACE_METHOD_B( char )
    DECL_TRACE_METHOD_B( short )
    DECL_TRACE_METHOD_B( int )
@@ -23,6 +23,7 @@
 #define VERILATOR_VERILATED_VCD_SC_H_

 #include "verilatedos.h"
+
 #include "verilated_sc.h"
 #include "verilated_vcd_c.h"

@@ -54,34 +55,34 @@ public:
        spTrace()->set_time_resolution(sc_get_time_resolution().to_string());
    }
    /// Destruct, flush, and close the dump
-    virtual ~VerilatedVcdSc() { close(); }
+    ~VerilatedVcdSc() override { close(); }

    // METHODS - for SC kernel
    // Called by SystemC simulate()
-    virtual void cycle(bool delta_cycle) {
+    void cycle(bool delta_cycle) override {
        if (!delta_cycle) this->dump(sc_time_stamp().to_double());
    }

    // Override VerilatedVcdC. Must be called after starting simulation.
-    virtual void open(const char* filename) /*override*/ VL_MT_SAFE;
+    void open(const char* filename) override VL_MT_SAFE;

 private:
    // METHODS - Fake outs for linker

 #ifdef NC_SYSTEMC
    // Cadence Incisive has these as abstract functions so we must create them
-    virtual void set_time_unit(int exponent10_seconds) {}  // deprecated
+    void set_time_unit(int exponent10_seconds) override {}  // deprecated
 #endif
-    virtual void set_time_unit(double v, sc_time_unit tu) {}  // LCOV_EXCL_LINE
+    void set_time_unit(double v, sc_time_unit tu) override {}  // LCOV_EXCL_LINE

 //--------------------------------------------------
 // SystemC 2.1.v1
-#define DECL_TRACE_METHOD_A(tp) virtual void trace(const tp& object, const std::string& name);
+#define DECL_TRACE_METHOD_A(tp) void trace(const tp& object, const std::string& name) override;
 #define DECL_TRACE_METHOD_B(tp) \
-    virtual void trace(const tp& object, const std::string& name, int width);
+    void trace(const tp& object, const std::string& name, int width) override;

-    virtual void write_comment(const std::string&);
-    virtual void trace(const unsigned int&, const std::string&, const char**);
+    void write_comment(const std::string&) override;
+    void trace(const unsigned int&, const std::string&, const char**) override;

    // clang-format off
    // Formatting matches that of sc_trace.h
@@ -98,9 +99,6 @@ private:
    DECL_TRACE_METHOD_B( unsigned short )
    DECL_TRACE_METHOD_B( unsigned int )
    DECL_TRACE_METHOD_B( unsigned long )
-#ifdef SYSTEMC_64BIT_PATCHES
-    DECL_TRACE_METHOD_B( unsigned long long)
-#endif
    DECL_TRACE_METHOD_B( char )
    DECL_TRACE_METHOD_B( short )
    DECL_TRACE_METHOD_B( int )
@@ -26,8 +26,9 @@

 #define VERILATOR_VERILATED_VPI_CPP_

-#include "verilated.h"
 #include "verilated_vpi.h"
+
+#include "verilated.h"
 #include "verilated_imp.h"

 #include <list>
@@ -66,11 +67,11 @@ class VerilatedVpio VL_NOT_FINAL {
    // CONSTANTS
    // Magic value stored in front of object to detect double free etc
    // Must be odd, as aligned pointer can never be odd
-    static constexpr vluint32_t activeMagic() { return 0xfeed100f; }
+    static constexpr uint32_t activeMagic() { return 0xfeed100f; }

    // MEM MANGLEMENT
    // Internal note: Globals may multi-construct, see verilated.cpp top.
-    static VL_THREAD_LOCAL vluint8_t* t_freeHead;
+    static VL_THREAD_LOCAL uint8_t* t_freeHead;

 public:
    // CONSTRUCTORS
@@ -81,22 +82,23 @@ public:
        // To simplify our free list, we use a size large enough for all derived types
        // We reserve word zero for the next pointer, as that's safer in case a
        // dangling reference to the original remains around.
-        static const size_t chunk = 96;
-        if (VL_UNCOVERABLE(size > chunk)) VL_FATAL_MT(__FILE__, __LINE__, "", "increase chunk");
+        static constexpr size_t CHUNK_SIZE = 96;
+        if (VL_UNCOVERABLE(size > CHUNK_SIZE))
+            VL_FATAL_MT(__FILE__, __LINE__, "", "increase CHUNK_SIZE");
        if (VL_LIKELY(t_freeHead)) {
-            vluint8_t* const newp = t_freeHead;
-            t_freeHead = *(reinterpret_cast<vluint8_t**>(newp));
-            *(reinterpret_cast<vluint32_t*>(newp)) = activeMagic();
+            uint8_t* const newp = t_freeHead;
+            t_freeHead = *(reinterpret_cast<uint8_t**>(newp));
+            *(reinterpret_cast<uint32_t*>(newp)) = activeMagic();
            return newp + 8;
        }
        // +8: 8 bytes for next
-        vluint8_t* newp = reinterpret_cast<vluint8_t*>(::operator new(chunk + 8));
-        *(reinterpret_cast<vluint32_t*>(newp)) = activeMagic();
+        uint8_t* newp = reinterpret_cast<uint8_t*>(::operator new(CHUNK_SIZE + 8));
+        *(reinterpret_cast<uint32_t*>(newp)) = activeMagic();
        return newp + 8;
    }
-    static void operator delete(void* obj, size_t /*size*/)VL_MT_SAFE {
-        vluint8_t* const oldp = (static_cast<vluint8_t*>(obj)) - 8;
-        if (VL_UNLIKELY(*(reinterpret_cast<vluint32_t*>(oldp)) != activeMagic())) {
+    static void operator delete(void* obj, size_t /*size*/) VL_MT_SAFE {
+        uint8_t* const oldp = (static_cast<uint8_t*>(obj)) - 8;
+        if (VL_UNLIKELY(*(reinterpret_cast<uint32_t*>(oldp)) != activeMagic())) {
            VL_FATAL_MT(__FILE__, __LINE__, "",
                        "vpi_release_handle() called on same object twice, or on non-Verilator "
                        "VPI object");
@@ -112,13 +114,13 @@ public:
    static VerilatedVpio* castp(vpiHandle h) {
        return dynamic_cast<VerilatedVpio*>(reinterpret_cast<VerilatedVpio*>(h));
    }
-    inline vpiHandle castVpiHandle() { return reinterpret_cast<vpiHandle>(this); }
+    vpiHandle castVpiHandle() { return reinterpret_cast<vpiHandle>(this); }
    // ACCESSORS
    virtual const char* name() const { return "<null>"; }
    virtual const char* fullname() const { return "<null>"; }
    virtual const char* defname() const { return "<null>"; }
-    virtual vluint32_t type() const { return 0; }
-    virtual vluint32_t size() const { return 0; }
+    virtual uint32_t type() const { return 0; }
+    virtual uint32_t size() const { return 0; }
    virtual const VerilatedRange* rangep() const { return nullptr; }
    virtual vpiHandle dovpi_scan() { return nullptr; }
    virtual PLI_INT32 dovpi_remove_cb() { return 0; }
@@ -127,52 +129,52 @@ public:
 class VerilatedVpioTimedCb final : public VerilatedVpio {
    // A handle to a timed callback created with vpi_register_cb
    // User can call vpi_remove_cb or vpi_release_handle on it
-    const vluint64_t m_id;  // Unique id/sequence number to find schedule's event
+    const uint64_t m_id;  // Unique id/sequence number to find schedule's event
    const QData m_time;

 public:
-    VerilatedVpioTimedCb(vluint64_t id, QData time)
+    VerilatedVpioTimedCb(uint64_t id, QData time)
        : m_id{id}
        , m_time{time} {}
-    virtual ~VerilatedVpioTimedCb() override = default;
+    ~VerilatedVpioTimedCb() override = default;
    static VerilatedVpioTimedCb* castp(vpiHandle h) {
        return dynamic_cast<VerilatedVpioTimedCb*>(reinterpret_cast<VerilatedVpioTimedCb*>(h));
    }
-    virtual vluint32_t type() const override { return vpiCallback; }
-    virtual PLI_INT32 dovpi_remove_cb() override;
+    uint32_t type() const override { return vpiCallback; }
+    PLI_INT32 dovpi_remove_cb() override;
 };

 class VerilatedVpioReasonCb final : public VerilatedVpio {
    // A handle to a non-timed callback created with vpi_register_cb
    // User can call vpi_remove_cb or vpi_release_handle on it
-    const vluint64_t m_id;  // Unique id/sequence number to find schedule's event
+    const uint64_t m_id;  // Unique id/sequence number to find schedule's event
    const PLI_INT32 m_reason;  // VPI callback reason code

 public:
    // cppcheck-suppress uninitVar  // m_value
-    VerilatedVpioReasonCb(vluint64_t id, PLI_INT32 reason)
+    VerilatedVpioReasonCb(uint64_t id, PLI_INT32 reason)
        : m_id{id}
        , m_reason{reason} {}
-    virtual ~VerilatedVpioReasonCb() override = default;
+    ~VerilatedVpioReasonCb() override = default;
    static VerilatedVpioReasonCb* castp(vpiHandle h) {
        return dynamic_cast<VerilatedVpioReasonCb*>(reinterpret_cast<VerilatedVpioReasonCb*>(h));
    }
-    virtual vluint32_t type() const override { return vpiCallback; }
-    virtual PLI_INT32 dovpi_remove_cb() override;
+    uint32_t type() const override { return vpiCallback; }
+    PLI_INT32 dovpi_remove_cb() override;
 };

 class VerilatedVpioConst final : public VerilatedVpio {
-    const vlsint32_t m_num;
+    const int32_t m_num;

 public:
-    explicit VerilatedVpioConst(vlsint32_t num)
+    explicit VerilatedVpioConst(int32_t num)
        : m_num{num} {}
-    virtual ~VerilatedVpioConst() override = default;
+    ~VerilatedVpioConst() override = default;
    static VerilatedVpioConst* castp(vpiHandle h) {
        return dynamic_cast<VerilatedVpioConst*>(reinterpret_cast<VerilatedVpio*>(h));
    }
-    virtual vluint32_t type() const override { return vpiConstant; }
-    vlsint32_t num() const { return m_num; }
+    uint32_t type() const override { return vpiConstant; }
+    int32_t num() const { return m_num; }
 };

 class VerilatedVpioVarBase VL_NOT_FINAL : public VerilatedVpio {
@@ -199,10 +201,10 @@ public:
    }
    const VerilatedVar* varp() const { return m_varp; }
    const VerilatedScope* scopep() const { return m_scopep; }
-    virtual vluint32_t size() const override { return get_range().elements(); }
-    virtual const VerilatedRange* rangep() const override { return &get_range(); }
-    virtual const char* name() const override { return m_varp->name(); }
-    virtual const char* fullname() const override {
+    uint32_t size() const override { return get_range().elements(); }
+    const VerilatedRange* rangep() const override { return &get_range(); }
+    const char* name() const override { return m_varp->name(); }
+    const char* fullname() const override {
        static VL_THREAD_LOCAL std::string t_out;
        t_out = std::string{m_scopep->name()} + "." + name();
        return t_out.c_str();
@@ -213,12 +215,12 @@ class VerilatedVpioParam final : public VerilatedVpioVarBase {
 public:
    VerilatedVpioParam(const VerilatedVar* varp, const VerilatedScope* scopep)
        : VerilatedVpioVarBase{varp, scopep} {}
-    virtual ~VerilatedVpioParam() override = default;
+    ~VerilatedVpioParam() override = default;

    static VerilatedVpioParam* castp(vpiHandle h) {
        return dynamic_cast<VerilatedVpioParam*>(reinterpret_cast<VerilatedVpio*>(h));
    }
-    virtual vluint32_t type() const override { return vpiParameter; }
+    uint32_t type() const override { return vpiParameter; }
    void* varDatap() const { return m_varp->datap(); }
 };

@@ -228,13 +230,13 @@ class VerilatedVpioRange final : public VerilatedVpio {
 public:
    explicit VerilatedVpioRange(const VerilatedRange* range)
        : m_range{range} {}
-    virtual ~VerilatedVpioRange() override = default;
+    ~VerilatedVpioRange() override = default;
    static VerilatedVpioRange* castp(vpiHandle h) {
        return dynamic_cast<VerilatedVpioRange*>(reinterpret_cast<VerilatedVpio*>(h));
    }
-    virtual vluint32_t type() const override { return vpiRange; }
-    virtual vluint32_t size() const override { return m_range->elements(); }
-    virtual const VerilatedRange* rangep() const override { return m_range; }
+    uint32_t type() const override { return vpiRange; }
+    uint32_t size() const override { return m_range->elements(); }
+    const VerilatedRange* rangep() const override { return m_range; }
 };

 class VerilatedVpioRangeIter final : public VerilatedVpio {
@@ -245,12 +247,12 @@ class VerilatedVpioRangeIter final : public VerilatedVpio {
 public:
    explicit VerilatedVpioRangeIter(const VerilatedRange* range)
        : m_range{range} {}
-    virtual ~VerilatedVpioRangeIter() override = default;
+    ~VerilatedVpioRangeIter() override = default;
    static VerilatedVpioRangeIter* castp(vpiHandle h) {
        return dynamic_cast<VerilatedVpioRangeIter*>(reinterpret_cast<VerilatedVpio*>(h));
    }
-    virtual vluint32_t type() const override { return vpiIterator; }
-    virtual vpiHandle dovpi_scan() override {
+    uint32_t type() const override { return vpiIterator; }
+    vpiHandle dovpi_scan() override {
        if (VL_UNLIKELY(m_done)) {
            delete this;  // IEEE 37.2.2 vpi_scan at end does a vpi_release_handle
            return nullptr;
@@ -267,26 +269,26 @@ protected:
 public:
    explicit VerilatedVpioScope(const VerilatedScope* scopep)
        : m_scopep{scopep} {}
-    virtual ~VerilatedVpioScope() override = default;
+    ~VerilatedVpioScope() override = default;
    static VerilatedVpioScope* castp(vpiHandle h) {
        return dynamic_cast<VerilatedVpioScope*>(reinterpret_cast<VerilatedVpio*>(h));
    }
-    virtual vluint32_t type() const override { return vpiScope; }
+    uint32_t type() const override { return vpiScope; }
    const VerilatedScope* scopep() const { return m_scopep; }
-    virtual const char* name() const override { return m_scopep->name(); }
-    virtual const char* fullname() const override { return m_scopep->name(); }
+    const char* name() const override { return m_scopep->name(); }
+    const char* fullname() const override { return m_scopep->name(); }
 };

 class VerilatedVpioVar VL_NOT_FINAL : public VerilatedVpioVarBase {
-    vluint8_t* m_prevDatap = nullptr;  // Previous value of data, for cbValueChange
+    uint8_t* m_prevDatap = nullptr;  // Previous value of data, for cbValueChange
    union {
-        vluint8_t u8[4];
-        vluint32_t u32;
+        uint8_t u8[4];
+        uint32_t u32;
    } m_mask;  // memoized variable mask
-    vluint32_t m_entSize = 0;  // memoized variable size
+    uint32_t m_entSize = 0;  // memoized variable size
 protected:
    void* m_varDatap = nullptr;  // varp()->datap() adjusted for array entries
-    vlsint32_t m_index = 0;
+    int32_t m_index = 0;

 public:
    VerilatedVpioVar(const VerilatedVar* varp, const VerilatedScope* scopep)
@@ -307,24 +309,24 @@ public:
            m_mask.u32 = 0;
        }
    }
-    virtual ~VerilatedVpioVar() override {
+    ~VerilatedVpioVar() override {
        if (m_prevDatap) VL_DO_CLEAR(delete[] m_prevDatap, m_prevDatap = nullptr);
    }
    static VerilatedVpioVar* castp(vpiHandle h) {
        return dynamic_cast<VerilatedVpioVar*>(reinterpret_cast<VerilatedVpio*>(h));
    }
-    vluint32_t mask() const { return m_mask.u32; }
-    vluint8_t mask_byte(int idx) const { return m_mask.u8[idx & 3]; }
-    vluint32_t entSize() const { return m_entSize; }
-    vluint32_t index() const { return m_index; }
-    virtual vluint32_t type() const override {
+    uint32_t mask() const { return m_mask.u32; }
+    uint8_t mask_byte(int idx) const { return m_mask.u8[idx & 3]; }
+    uint32_t entSize() const { return m_entSize; }
+    uint32_t index() const { return m_index; }
+    uint32_t type() const override {
        return (varp()->dims() > 1) ? vpiMemory : vpiReg;  // but might be wire, logic
    }
    void* prevDatap() const { return m_prevDatap; }
    void* varDatap() const { return m_varDatap; }
    void createPrevDatap() {
        if (VL_UNLIKELY(!m_prevDatap)) {
-            m_prevDatap = new vluint8_t[entSize()];
+            m_prevDatap = new uint8_t[entSize()];
            std::memcpy(prevDatap(), varp()->datap(), entSize());
        }
    }
@@ -332,20 +334,20 @@ public:

 class VerilatedVpioMemoryWord final : public VerilatedVpioVar {
 public:
-    VerilatedVpioMemoryWord(const VerilatedVar* varp, const VerilatedScope* scopep,
-                            vlsint32_t index, int offset)
+    VerilatedVpioMemoryWord(const VerilatedVar* varp, const VerilatedScope* scopep, int32_t index,
+                            int offset)
        : VerilatedVpioVar{varp, scopep} {
        m_index = index;
-        m_varDatap = (static_cast<vluint8_t*>(varp->datap())) + entSize() * offset;
+        m_varDatap = (static_cast<uint8_t*>(varp->datap())) + entSize() * offset;
    }
-    virtual ~VerilatedVpioMemoryWord() override = default;
+    ~VerilatedVpioMemoryWord() override = default;
    static VerilatedVpioMemoryWord* castp(vpiHandle h) {
        return dynamic_cast<VerilatedVpioMemoryWord*>(reinterpret_cast<VerilatedVpio*>(h));
    }
-    virtual vluint32_t type() const override { return vpiMemoryWord; }
-    virtual vluint32_t size() const override { return varp()->packed().elements(); }
-    virtual const VerilatedRange* rangep() const override { return &(varp()->packed()); }
-    virtual const char* fullname() const override {
+    uint32_t type() const override { return vpiMemoryWord; }
+    uint32_t size() const override { return varp()->packed().elements(); }
+    const VerilatedRange* rangep() const override { return &(varp()->packed()); }
+    const char* fullname() const override {
        static VL_THREAD_LOCAL std::string t_out;
        constexpr size_t LEN_MAX_INDEX = 25;
        char num[LEN_MAX_INDEX];
@@ -363,12 +365,12 @@ class VerilatedVpioVarIter final : public VerilatedVpio {
 public:
    explicit VerilatedVpioVarIter(const VerilatedScope* scopep)
        : m_scopep{scopep} {}
-    virtual ~VerilatedVpioVarIter() override = default;
+    ~VerilatedVpioVarIter() override = default;
    static VerilatedVpioVarIter* castp(vpiHandle h) {
        return dynamic_cast<VerilatedVpioVarIter*>(reinterpret_cast<VerilatedVpio*>(h));
    }
-    virtual vluint32_t type() const override { return vpiIterator; }
-    virtual vpiHandle dovpi_scan() override {
+    uint32_t type() const override { return vpiIterator; }
+    vpiHandle dovpi_scan() override {
        if (VL_LIKELY(m_scopep->varsp())) {
            const VerilatedVarNameMap* const varsp = m_scopep->varsp();
            if (VL_UNLIKELY(!m_started)) {
@@ -394,8 +396,8 @@ public:
 class VerilatedVpioMemoryWordIter final : public VerilatedVpio {
    const vpiHandle m_handle;
    const VerilatedVar* const m_varp;
-    vlsint32_t m_iteration;
-    const vlsint32_t m_direction;
+    int32_t m_iteration;
+    const int32_t m_direction;
    bool m_done = false;

 public:
@@ -404,15 +406,15 @@ public:
        , m_varp{varp}
        , m_iteration{varp->unpacked().right()}
        , m_direction{VL_LIKELY(varp->unpacked().left() > varp->unpacked().right()) ? 1 : -1} {}
-    virtual ~VerilatedVpioMemoryWordIter() override = default;
+    ~VerilatedVpioMemoryWordIter() override = default;
    static VerilatedVpioMemoryWordIter* castp(vpiHandle h) {
        return dynamic_cast<VerilatedVpioMemoryWordIter*>(reinterpret_cast<VerilatedVpio*>(h));
    }
-    virtual vluint32_t type() const override { return vpiIterator; }
+    uint32_t type() const override { return vpiIterator; }
    void iterationInc() {
        if (!(m_done = (m_iteration == m_varp->unpacked().left()))) m_iteration += m_direction;
    }
-    virtual vpiHandle dovpi_scan() override {
+    vpiHandle dovpi_scan() override {
        if (VL_UNLIKELY(m_done)) {
            delete this;  // IEEE 37.2.2 vpi_scan at end does a vpi_release_handle
            return nullptr;
@@ -437,9 +439,9 @@ public:
    static VerilatedVpioModule* castp(vpiHandle h) {
        return dynamic_cast<VerilatedVpioModule*>(reinterpret_cast<VerilatedVpio*>(h));
    }
-    virtual vluint32_t type() const override { return vpiModule; }
-    virtual const char* name() const override { return m_name; }
-    virtual const char* fullname() const override { return m_fullname; }
+    uint32_t type() const override { return vpiModule; }
+    const char* name() const override { return m_name; }
+    const char* fullname() const override { return m_fullname; }
 };

 class VerilatedVpioModuleIter final : public VerilatedVpio {
@@ -451,12 +453,12 @@ public:
        : m_vec{&vec} {
        m_it = m_vec->begin();
    }
-    virtual ~VerilatedVpioModuleIter() override = default;
+    ~VerilatedVpioModuleIter() override = default;
    static VerilatedVpioModuleIter* castp(vpiHandle h) {
        return dynamic_cast<VerilatedVpioModuleIter*>(reinterpret_cast<VerilatedVpio*>(h));
    }
-    virtual vluint32_t type() const override { return vpiIterator; }
-    virtual vpiHandle dovpi_scan() override {
+    uint32_t type() const override { return vpiIterator; }
+    vpiHandle dovpi_scan() override {
        if (m_it == m_vec->end()) {
            delete this;  // IEEE 37.2.2 vpi_scan at end does a vpi_release_handle
            return nullptr;
@@ -472,14 +474,14 @@ using VerilatedPliCb = PLI_INT32 (*)(struct t_cb_data*);

 class VerilatedVpiCbHolder final {
    // Holds information needed to call a callback
-    vluint64_t m_id;
+    uint64_t m_id;
    s_cb_data m_cbData;
    s_vpi_value m_value;
    VerilatedVpioVar m_varo;  // If a cbValueChange callback, the object we will return

 public:
    // cppcheck-suppress uninitVar  // m_value
-    VerilatedVpiCbHolder(vluint64_t id, const s_cb_data* cbDatap, const VerilatedVpioVar* varop)
+    VerilatedVpiCbHolder(uint64_t id, const s_cb_data* cbDatap, const VerilatedVpioVar* varop)
        : m_id{id}
        , m_cbData{*cbDatap}
        , m_varo{varop} {
@@ -495,15 +497,15 @@ public:
    ~VerilatedVpiCbHolder() = default;
    VerilatedPliCb cb_rtnp() const { return m_cbData.cb_rtn; }
    s_cb_data* cb_datap() { return &m_cbData; }
-    vluint64_t id() const { return m_id; }
+    uint64_t id() const { return m_id; }
    bool invalid() const { return !m_id; }
    void invalidate() { m_id = 0; }
 };

 struct VerilatedVpiTimedCbsCmp {
    // Ordering sets keyed by time, then callback unique id
-    bool operator()(const std::pair<QData, vluint64_t>& a,
-                    const std::pair<QData, vluint64_t>& b) const {
+    bool operator()(const std::pair<QData, uint64_t>& a,
+                    const std::pair<QData, uint64_t>& b) const {
        if (a.first < b.first) return true;
        if (a.first > b.first) return false;
        return a.second < b.second;
@@ -515,14 +517,14 @@ class VerilatedVpiError;
 class VerilatedVpiImp final {
    enum { CB_ENUM_MAX_VALUE = cbAtEndOfSimTime + 1 };  // Maxium callback reason
    using VpioCbList = std::list<VerilatedVpiCbHolder>;
-    using VpioTimedCbs = std::map<std::pair<QData, vluint64_t>, VerilatedVpiCbHolder>;
+    using VpioTimedCbs = std::map<std::pair<QData, uint64_t>, VerilatedVpiCbHolder>;

    // All only medium-speed, so use singleton function
    VpioCbList m_cbObjLists[CB_ENUM_MAX_VALUE];  // Callbacks for each supported reason
    VpioTimedCbs m_timedCbs;  // Time based callbacks
    VerilatedVpiError* m_errorInfop = nullptr;  // Container for vpi error info
    VerilatedAssertOneThread m_assertOne;  // Assert only called from single thread
-    vluint64_t m_nextCallbackId = 1;  // Id to identify callback
+    uint64_t m_nextCallbackId = 1;  // Id to identify callback

    static VerilatedVpiImp& s() {  // Singleton
        static VerilatedVpiImp s_s;
@@ -531,9 +533,9 @@ class VerilatedVpiImp final {

 public:
    static void assertOneCheck() { s().m_assertOne.check(); }
-    static vluint64_t nextCallbackId() { return ++s().m_nextCallbackId; }
+    static uint64_t nextCallbackId() { return ++s().m_nextCallbackId; }

-    static void cbReasonAdd(vluint64_t id, const s_cb_data* cb_data_p) {
+    static void cbReasonAdd(uint64_t id, const s_cb_data* cb_data_p) {
        // The passed cb_data_p was property of the user, so need to recreate
        if (VL_UNCOVERABLE(cb_data_p->reason >= CB_ENUM_MAX_VALUE)) {
            VL_FATAL_MT(__FILE__, __LINE__, "", "vpi bb reason too large");
@@ -544,7 +546,7 @@ public:
        if (cb_data_p->reason == cbValueChange) varop = VerilatedVpioVar::castp(cb_data_p->obj);
        s().m_cbObjLists[cb_data_p->reason].emplace_back(id, cb_data_p, varop);
    }
-    static void cbTimedAdd(vluint64_t id, const s_cb_data* cb_data_p, QData time) {
+    static void cbTimedAdd(uint64_t id, const s_cb_data* cb_data_p, QData time) {
        // The passed cb_data_p was property of the user, so need to recreate
        VL_DEBUG_IF_PLI(VL_DBG_MSGF("- vpi: vpi_register_cb reason=%d id=%" PRId64
                                    " delay=%" PRIu64 "\n",
@@ -553,7 +555,7 @@ public:
                               std::forward_as_tuple(std::make_pair(time, id)),
                               std::forward_as_tuple(id, cb_data_p, nullptr));
    }
-    static void cbReasonRemove(vluint64_t id, vluint32_t reason) {
+    static void cbReasonRemove(uint64_t id, uint32_t reason) {
        // Id might no longer exist, if already removed due to call after event, or teardown
        VpioCbList& cbObjList = s().m_cbObjLists[reason];
        // We do not remove it now as we may be iterating the list,
@@ -562,7 +564,7 @@ public:
            if (ir.id() == id) ir.invalidate();
        }
    }
-    static void cbTimedRemove(vluint64_t id, QData time) {
+    static void cbTimedRemove(uint64_t id, QData time) {
        // Id might no longer exist, if already removed due to call after event, or teardown
        const auto it = s().m_timedCbs.find(std::make_pair(time, id));
        if (VL_LIKELY(it != s().m_timedCbs.end())) it->second.invalidate();
@@ -592,7 +594,7 @@ public:
        if (VL_LIKELY(it != s().m_timedCbs.cend())) return it->first.first;
        return ~0ULL;  // maxquad
    }
-    static bool callCbs(const vluint32_t reason) VL_MT_UNSAFE_ONE {
+    static bool callCbs(const uint32_t reason) VL_MT_UNSAFE_ONE {
        VpioCbList& cbObjList = s().m_cbObjLists[reason];
        bool called = false;
        if (cbObjList.empty()) return called;
@@ -664,7 +666,7 @@ public:
 // Statics
 // Internal note: Globals may multi-construct, see verilated.cpp top.

-VL_THREAD_LOCAL vluint8_t* VerilatedVpio::t_freeHead = nullptr;
+VL_THREAD_LOCAL uint8_t* VerilatedVpio::t_freeHead = nullptr;

 //======================================================================
 // VerilatedVpiError
@@ -744,7 +746,7 @@ void VerilatedVpi::callTimedCbs() VL_MT_UNSAFE_ONE { VerilatedVpiImp::callTimedC

 bool VerilatedVpi::callValueCbs() VL_MT_UNSAFE_ONE { return VerilatedVpiImp::callValueCbs(); }

-bool VerilatedVpi::callCbs(vluint32_t reason) VL_MT_UNSAFE_ONE {
+bool VerilatedVpi::callCbs(uint32_t reason) VL_MT_UNSAFE_ONE {
    return VerilatedVpiImp::callCbs(reason);
 }

@@ -1309,7 +1311,7 @@ vpiHandle vpi_register_cb(p_cb_data cb_data_p) {
        QData time = 0;
        if (cb_data_p->time) time = VL_SET_QII(cb_data_p->time->high, cb_data_p->time->low);
        const QData abstime = VL_TIME_Q() + time;
-        const vluint64_t id = VerilatedVpiImp::nextCallbackId();
+        const uint64_t id = VerilatedVpiImp::nextCallbackId();
        VerilatedVpioTimedCb* const vop = new VerilatedVpioTimedCb{id, abstime};
        VerilatedVpiImp::cbTimedAdd(id, cb_data_p, abstime);
        return vop->castVpiHandle();
@@ -1324,7 +1326,7 @@ vpiHandle vpi_register_cb(p_cb_data cb_data_p) {
    case cbEnterInteractive:  // FALLTHRU // NOP, but need to return handle, so make object
    case cbExitInteractive:  // FALLTHRU // NOP, but need to return handle, so make object
    case cbInteractiveScopeChange: {  // FALLTHRU // NOP, but need to return handle, so make object
-        const vluint64_t id = VerilatedVpiImp::nextCallbackId();
+        const uint64_t id = VerilatedVpiImp::nextCallbackId();
        VerilatedVpioReasonCb* const vop = new VerilatedVpioReasonCb{id, cb_data_p->reason};
        VerilatedVpiImp::cbReasonAdd(id, cb_data_p);
        return vop->castVpiHandle();
@@ -1474,7 +1476,7 @@ vpiHandle vpi_handle(PLI_INT32 type, vpiHandle object) {
    case vpiIndex: {
        const VerilatedVpioVar* const vop = VerilatedVpioVar::castp(object);
        if (VL_UNLIKELY(!vop)) return nullptr;
-        const vlsint32_t val = vop->index();
+        const int32_t val = vop->index();
        return (new VerilatedVpioConst{val})->castVpiHandle();
    }
    case vpiScope: {
@@ -1996,7 +1998,7 @@ vpiHandle vpi_put_value(vpiHandle object, p_vpi_value valuep, p_vpi_time /*time_
            for (int i = 0; i < chars; ++i) {
                union {
                    char byte[2];
-                    vluint16_t half;
+                    uint16_t half;
                } val;
                idx = div(i * 3, 8);
                if (i < len) {
@@ -25,6 +25,7 @@
 #define VERILATOR_VERILATED_VPI_H_

 #include "verilatedos.h"
+
 #include "verilated.h"
 #include "verilated_syms.h"

@@ -47,7 +48,7 @@ public:
    static bool callValueCbs() VL_MT_UNSAFE_ONE;
    /// Call callbacks of arbitrary types.
    /// User wrapper code should call this from their main loops.
-    static bool callCbs(const vluint32_t reason) VL_MT_UNSAFE_ONE;
+    static bool callCbs(uint32_t reason) VL_MT_UNSAFE_ONE;
    /// Returns time of the next registered VPI callback, or
    /// ~(0ULL) if none are registered
    static QData cbNextDeadline() VL_MT_UNSAFE_ONE;
@@ -39,7 +39,8 @@

 #ifdef __GNUC__
 # define VL_ATTR_ALIGNED(alignment) __attribute__((aligned(alignment)))
-# define VL_ATTR_ALWINLINE __attribute__((always_inline))
+# define VL_ATTR_ALWINLINE __attribute__((always_inline)) inline
+# define VL_ATTR_NOINLINE __attribute__((noinline))
 # define VL_ATTR_COLD __attribute__((cold))
 # define VL_ATTR_HOT __attribute__((hot))
 # define VL_ATTR_NORETURN __attribute__((noreturn))
@@ -82,6 +83,9 @@
 #ifndef VL_ATTR_ALWINLINE
 # define VL_ATTR_ALWINLINE  ///< Attribute to inline, even when not optimizing
 #endif
+#ifndef VL_ATTR_NOINLINE
+# define VL_ATTR_NOINLINE  ///< Attribute to never inline, even when optimizing
+#endif
 #ifndef VL_ATTR_COLD
 # define VL_ATTR_COLD  ///< Attribute that function is rarely executed
 #endif
@@ -214,22 +218,33 @@
 // C++-2011

 #if __cplusplus >= 201103L || defined(__GXX_EXPERIMENTAL_CXX0X__) || defined(VL_CPPCHECK)
-# ifndef VL_NO_LEGACY
-// These are deprecated historical defines. We leave them in case users referenced them.
-#  define VL_EQ_DELETE = delete
-#  define vl_unique_ptr std::unique_ptr
-#  define vl_unordered_map std::unordered_map
-#  define vl_unordered_set std::unordered_set
-#  define VL_INCLUDE_UNORDERED_MAP <unordered_map>
-#  define VL_INCLUDE_UNORDERED_SET <unordered_set>
-#  define VL_FINAL final
-#  define VL_MUTABLE mutable
-#  define VL_OVERRIDE override
-# endif
 #else
 # error "Verilator requires a C++11 or newer compiler"
 #endif

+#ifndef VL_NO_LEGACY
+// These are deprecated historical defines. We leave them in case users referenced them.
+# define VL_EQ_DELETE = delete
+# define vl_unique_ptr std::unique_ptr
+# define vl_unordered_map std::unordered_map
+# define vl_unordered_set std::unordered_set
+# define VL_INCLUDE_UNORDERED_MAP <unordered_map>
+# define VL_INCLUDE_UNORDERED_SET <unordered_set>
+# define VL_FINAL final
+# define VL_MUTABLE mutable
+# define VL_OVERRIDE override
+#endif
+
+//=========================================================================
+// C++-2017
+
+#if __cplusplus >= 201703L
+# define VL_CONSTEXPR_CXX17 constexpr
+#else
+# define VL_CONSTEXPR_CXX17
+#endif
+
+
 //=========================================================================
 // Optimization

@@ -241,14 +256,11 @@
 // Internal coverage

 #ifdef VL_GCOV
-extern "C" {
-void __gcov_flush();  // gcc sources gcc/gcov-io.h has the prototype
-}
-// Flush internal code coverage data before e.g. std::abort()
-# define VL_GCOV_FLUSH() \
-    __gcov_flush()
+extern "C" void __gcov_dump();
+// Dump internal code coverage data before e.g. std::abort()
+# define VL_GCOV_DUMP() __gcov_dump()
 #else
-# define VL_GCOV_FLUSH()
+# define VL_GCOV_DUMP()
 #endif

 //=========================================================================
@@ -282,6 +294,7 @@ void __gcov_flush();  // gcc sources gcc/gcov-io.h has the prototype
 #include <cstdint>
 #include <cinttypes>

+#ifndef VL_NO_LEGACY
 using vluint8_t = uint8_t;  ///< 8-bit unsigned type (backward compatibility)
 using vluint16_t = uint16_t;  ///< 16-bit unsigned type (backward compatibility)
 using vluint32_t = uint32_t;  ///< 32-bit unsigned type (backward compatibility)
@@ -290,6 +303,7 @@ using vlsint8_t = int8_t;  ///< 8-bit signed type (backward compatibility)
 using vlsint16_t = int16_t;  ///< 16-bit signed type (backward compatibility)
 using vlsint32_t = int32_t;  ///< 32-bit signed type (backward compatibility)
 using vlsint64_t = int64_t;  ///< 64-bit signed type (backward compatibility)
+#endif

 #if defined(__CYGWIN__)

@@ -320,12 +334,12 @@ using ssize_t = uint32_t;  ///< signed size_t; returned from read()
 // Deprecated, favor C++11's PRIx64, etc, instead
 #ifndef VL_NO_LEGACY
 # ifdef _MSC_VER
-#  define VL_PRI64 "I64"  ///< print a vluint64_t (backward compatibility)
+#  define VL_PRI64 "I64"  ///< print a uint64_t (backward compatibility)
 # else  // use standard C99 format specifiers
 #  if defined(__WORDSIZE) && (__WORDSIZE == 64)
-#   define VL_PRI64 "l"  ///< print a vluint64_t (backward compatibility)
+#   define VL_PRI64 "l"  ///< print a uint64_t (backward compatibility)
 #  else
-#   define VL_PRI64 "ll"  ///< print a vluint64_t (backward compatibility)
+#   define VL_PRI64 "ll"  ///< print a uint64_t (backward compatibility)
 #  endif
 # endif
 #endif
@@ -414,6 +428,12 @@ using ssize_t = uint32_t;  ///< signed size_t; returned from read()
 #define VL_BITBIT_Q(bit) ((bit) & VL_SIZEBITS_Q)  ///< Bit number for a bit in a quad
 #define VL_BITBIT_E(bit) ((bit) & VL_SIZEBITS_E)  ///< Bit number for a bit in a EData

+// Return true if data[bit] set; not 0/1 return, but 0/non-zero return.
+#define VL_BITISSET_I(data, bit) ((data) & (VL_UL(1) << VL_BITBIT_I(bit)))
+#define VL_BITISSET_Q(data, bit) ((data) & (1ULL << VL_BITBIT_Q(bit)))
+#define VL_BITISSET_E(data, bit) ((data) & (VL_EUL(1) << VL_BITBIT_E(bit)))
+#define VL_BITISSET_W(data, bit) ((data)[VL_BITWORD_E(bit)] & (VL_EUL(1) << VL_BITBIT_E(bit)))
+
 //=========================================================================
 // Floating point
 // #defines, to avoid requiring math.h on all compile runs
@@ -430,24 +450,25 @@ using ssize_t = uint32_t;  ///< signed size_t; returned from read()
 // Performance counters

 #if defined(__i386__) || defined(__x86_64__)
-// The vluint64_t argument is loaded with a high-performance counter for profiling
+// The uint64_t argument is loaded with a high-performance counter for profiling
 // or 0x0 if not implemented on this platform
-#define VL_RDTSC(val) \
+#define VL_GET_CPU_TICK(val) \
    { \
-        vluint32_t hi, lo; \
+        uint32_t hi; \
+        uint32_t lo; \
        asm volatile("rdtsc" : "=a"(lo), "=d"(hi)); \
-        (val) = ((vluint64_t)lo) | (((vluint64_t)hi) << 32); \
+        (val) = ((uint64_t)lo) | (((uint64_t)hi) << 32); \
    }
 #elif defined(__aarch64__)
 // 1 GHz virtual system timer on SBSA level 5 compliant systems, else often 100 MHz
-# define VL_RDTSC(val) \
+# define VL_GET_CPU_TICK(val) \
    { \
        asm volatile("isb" : : : "memory"); \
        asm volatile("mrs %[rt],CNTVCT_EL0" : [rt] "=r"(val)); \
    }
 #else
 // We just silently ignore unknown OSes, as only leads to missing statistics
-# define VL_RDTSC(val) (val) = 0;
+# define VL_GET_CPU_TICK(val) (val) = 0;
 #endif

 //=========================================================================
@@ -469,6 +490,9 @@ using ssize_t = uint32_t;  ///< signed size_t; returned from read()
 #  define VL_CPU_RELAX() asm volatile("yield" ::: "memory")
 # elif defined(__powerpc64__)
 #  define VL_CPU_RELAX() asm volatile("or 1, 1, 1; or 2, 2, 2;" ::: "memory")
+# elif defined(__loongarch__)
+// LoongArch does not currently have a yield/pause instruction
+#  define VL_CPU_RELAX() asm volatile("nop" ::: "memory")
 # else
 #  error "Missing VL_CPU_RELAX() definition. Or, don't use VL_THREADED"
 # endif
@@ -483,10 +507,8 @@ using ssize_t = uint32_t;  ///< signed size_t; returned from read()
 # define VL_STRCASECMP strcasecmp
 #endif

-#ifdef __MINGW32__
+#if defined(__MINGW32__) || defined(_MSC_VER)
 # define VL_LOCALTIME_R(timep, tmp) localtime_s((tmp), (timep))
-#elif defined(_MSC_VER)
-# define VL_LOCALTIME_R(timep, tmp) localtime_c((tmp), (timep))
 #else
 # define VL_LOCALTIME_R(timep, tmp) localtime_r((timep), (tmp))
 #endif
@@ -508,12 +530,40 @@ using ssize_t = uint32_t;  ///< signed size_t; returned from read()
 #define VL_STRINGIFY(x) VL_STRINGIFY2(x)
 #define VL_STRINGIFY2(x) #x

+//=========================================================================
+// Offset of field in type
+
+// Address zero can cause compiler problems
+#define VL_OFFSETOF(type, field) \
+    (reinterpret_cast<size_t>(&(reinterpret_cast<type*>(0x10000000)->field)) - 0x10000000)
+
 //=========================================================================
 // Conversions

 namespace vlstd {
+
+template <typename T>
+struct reverse_wrapper {
+    const T& m_v;
+
+    explicit reverse_wrapper(const T& a_v)
+        : m_v(a_v) {}
+    auto begin() -> decltype(m_v.rbegin()) { return m_v.rbegin(); }
+    auto end() -> decltype(m_v.rend()) { return m_v.rend(); }
+};
+
+// C++20's std::ranges::reverse_view
+template <typename T>
+reverse_wrapper<T> reverse_view(const T& v) {
+    return reverse_wrapper<T>(v);
+}
+
 // C++17's std::as_const
-template <class T> T const& as_const(T& v) { return v; }
+template <class T>
+T const& as_const(T& v) {
+    return v;
+}
+
 };  // namespace vlstd

 //=========================================================================
@@ -48,6 +48,7 @@ exclude_line_regexp(r'\bNUM_ASSERT')
 exclude_line_regexp(r'\bERROR_RSVD_WORD')
 exclude_line_regexp(r'\bV3ERROR_NA')
 exclude_line_regexp(r'\bUINFO\b')
+exclude_line_regexp(r'\bVL_DEFINE_DEBUG_FUNCTIONS\b')

 # Exclude for branch coverage only
 exclude_branch_regexp(r'\bdebug\(\)')
@@ -610,7 +610,7 @@ def getGcovCoverage(args):
        coverage_files = getFilteredCoverageFiles(coverage_files, args.excludepre)
        logging.info("Found {} coverage files after filtering".format(len(coverage_files)))

-    # We "zero" the "counters" by simply deleting all gcda files
+    # We "zero" the "counters" by deleting all gcda files
    if args.zerocounters:
        removeFiles(coverage_files)
        logging.info("Removed {} .gcda files".format(len(coverage_files)))
@@ -79,7 +79,7 @@ ifeq ($(VL_NOOPT),1)
 CPPFLAGS += -O0
 else ifeq ($(VL_DEBUG),)
 # Optimize
-CPPFLAGS += -O2
+CPPFLAGS += -O3
 else
 # Debug
 CPPFLAGS += @CFG_CXXFLAGS_DEBUG@ -DVL_DEBUG -D_GLIBCXX_DEBUG
@@ -276,9 +276,16 @@ VLCOV_OBJS = \

 NON_STANDALONE_HEADERS = \
 	V3AstInlines.h  \
-	V3AstNodes.h  \
+	V3AstNodeDType.h  \
+	V3AstNodeMath.h  \
+	V3AstNodeOther.h  \
 	V3WidthCommit.h  \

+AST_DEFS := \
+  V3AstNodeDType.h \
+  V3AstNodeMath.h \
+  V3AstNodeOther.h \
+
 #### Linking

 ifeq ($(VL_VLCOV),)
@@ -301,8 +308,8 @@ V3Number_test: V3Number_test.o

 #### Modules

-%__gen.cpp:	%.cpp $(ASTGEN) V3Ast.h V3AstNodes.h
-	$(PYTHON3) $(ASTGEN) -I $(srcdir) $*.cpp
+%__gen.cpp:	%.cpp $(ASTGEN) $(AST_DEFS)
+	$(PYTHON3) $(ASTGEN) -I $(srcdir) $(foreach f,$(AST_DEFS),--astdef $f) $*.cpp

 %.o:	%.cpp
 	$(OBJCACHE) ${CXX} ${CXXFLAGS} ${CPPFLAGSWALL} -c $< -o $@
@@ -332,8 +339,8 @@ vlcovgen.d: $(VLCOVGEN) $(srcdir)/../include/verilated_cov_key.h
 	$(PYTHON3) $(VLCOVGEN) --srcdir $(srcdir)
 	touch $@

-V3Ast__gen_classes.h : $(ASTGEN) V3Ast.h V3AstNodes.h
-	$(PYTHON3) $(ASTGEN) -I $(srcdir)  --classes
+V3Ast__gen_classes.h : $(ASTGEN) $(AST_DEFS)
+	$(PYTHON3) $(ASTGEN) -I $(srcdir) $(foreach f,$(AST_DEFS),--astdef $f) --classes

 V3ParseBison.h: V3ParseBison.c

@@ -29,16 +29,17 @@
 #include "config_build.h"
 #include "verilatedos.h"

-#include "V3Global.h"
 #include "V3Active.h"
+
 #include "V3Ast.h"
-#include "V3EmitCBase.h"
 #include "V3Const.h"
-#include "V3SenTree.h"  // for SenTreeSet
+#include "V3Global.h"
 #include "V3Graph.h"

 #include <unordered_map>

+VL_DEFINE_DEBUG_FUNCTIONS;
+
 //***** See below for main transformation engine

 //######################################################################
@@ -67,8 +68,8 @@ public:
        : V3GraphVertex{graphp}
        , m_name{name}
        , m_type{type} {}
-    virtual string name() const override { return m_name + " " + typestr(); }
-    virtual string dotColor() const override { return user() ? "green" : "black"; }
+    string name() const override { return m_name + " " + typestr(); }
+    string dotColor() const override { return user() ? "green" : "black"; }
    virtual int type() const { return m_type; }
 };

@@ -77,11 +78,9 @@ public:

 class LatchDetectGraph final : public V3Graph {
 protected:
-    LatchDetectGraphVertex* m_curVertexp;  // Current latch detection graph vertex
+    LatchDetectGraphVertex* m_curVertexp = nullptr;  // Current latch detection graph vertex
    std::vector<AstVarRef*> m_outputs;  // Vector of lvalues encountered on this pass

-    VL_DEBUG_FUNC;  // Declare debug()
-
    static LatchDetectGraphVertex* castVertexp(void* vertexp) {
        return reinterpret_cast<LatchDetectGraphVertex*>(vertexp);
    }
@@ -121,7 +120,7 @@ protected:

 public:
    LatchDetectGraph() { clear(); }
-    virtual ~LatchDetectGraph() override { clear(); }
+    ~LatchDetectGraph() override { clear(); }
    // ACCESSORS
    LatchDetectGraphVertex* currentp() { return m_curVertexp; }
    void currentp(LatchDetectGraphVertex* vertex) { m_curVertexp = vertex; }
@@ -184,7 +183,7 @@ public:
                        << " (not all control paths of combinational always assign a value)\n"
                        << nodep->warnMore()
                        << "... Suggest use of always_latch for intentional latches");
-                if (debug() >= 9) dumpDotFilePrefixed("latch_" + vrp->name());
+                if (dumpGraph() >= 9) dumpDotFilePrefixed("latch_" + vrp->name());
            }
            vertp->user(false);  // Clear again (see above)
            vrp->varp()->isLatched(latch_detected);
@@ -199,44 +198,37 @@ public:
 //######################################################################
 // Collect existing active names

-class ActiveBaseVisitor VL_NOT_FINAL : public VNVisitor {
-protected:
-    VL_DEBUG_FUNC;  // Declare debug()
-};
-
-class ActiveNamer final : public ActiveBaseVisitor {
+class ActiveNamer final : public VNVisitor {
 private:
    // STATE
    AstScope* m_scopep = nullptr;  // Current scope to add statement to
    AstActive* m_iActivep = nullptr;  // For current scope, the IActive we're building
    AstActive* m_cActivep = nullptr;  // For current scope, the SActive(combo) we're building

-    SenTreeSet m_activeSens;  // Sen lists for each active we've made
-    using ActiveMap = std::unordered_map<AstSenTree*, AstActive*>;
-    ActiveMap m_activeMap;  // Map sentree to active, for folding.
+    // Map from AstSenTree (equivalence) to the corresponding AstActive created.
+    std::unordered_map<VNRef<AstSenTree>, AstActive*> m_activeMap;

    // METHODS
    void addActive(AstActive* nodep) {
        UASSERT_OBJ(m_scopep, nodep, "nullptr scope");
-        m_scopep->addActivep(nodep);
+        m_scopep->addBlocksp(nodep);
    }
    // VISITORS
-    virtual void visit(AstScope* nodep) override {
+    void visit(AstScope* nodep) override {
        m_scopep = nodep;
        m_iActivep = nullptr;
        m_cActivep = nullptr;
-        m_activeSens.clear();
        m_activeMap.clear();
        iterateChildren(nodep);
        // Don't clear scopep, the namer persists beyond this visit
    }
-    virtual void visit(AstSenTree* nodep) override {
+    void visit(AstSenTree* nodep) override {
        // Simplify sensitivity list
        VL_DO_DANGLING(V3Const::constifyExpensiveEdit(nodep), nodep);
    }
    //--------------------
-    virtual void visit(AstNodeStmt*) override {}  // Accelerate
-    virtual void visit(AstNode* nodep) override { iterateChildren(nodep); }
+    void visit(AstNodeStmt*) override {}  // Accelerate
+    void visit(AstNode* nodep) override { iterateChildren(nodep); }

 public:
    // METHODS
@@ -259,42 +251,33 @@ public:
        }
        return m_iActivep;
    }
+
+    // Return an AstActive that is sensitive to a SenTree equivalent to the given sentreep.
    AstActive* getActive(FileLine* fl, AstSenTree* sensesp) {
-        // Return a sentree in this scope that matches given sense list.

-        AstActive* activep = nullptr;
-        AstSenTree* const activeSenp = m_activeSens.find(sensesp);
-        if (activeSenp) {
-            const auto it = m_activeMap.find(activeSenp);
-            UASSERT(it != m_activeMap.end(), "Corrupt active map");
-            activep = it->second;
-        }
+        auto it = m_activeMap.find(*sensesp);
+        // If found matching AstActive, return it
+        if (it != m_activeMap.end()) return it->second;

-        // Not found, form a new one
-        if (!activep) {
-            AstSenTree* const newsenp = sensesp->cloneTree(false);
-            activep = new AstActive(fl, "sequent", newsenp);
-            activep->sensesStorep(activep->sensesp());
-            UINFO(8, "    New ACTIVE " << activep << endl);
-            // Form the sensitivity list
-            addActive(activep);
-            m_activeMap[newsenp] = activep;
-            m_activeSens.add(newsenp);
-            // Note actives may have also been added above in the Active visitor
-        }
+        // No such AstActive yet, creat it, and add to map.
+        AstSenTree* const newsenp = sensesp->cloneTree(false);
+        AstActive* const activep = new AstActive(fl, "sequent", newsenp);
+        activep->sensesStorep(activep->sensesp());
+        addActive(activep);
+        m_activeMap.emplace(*newsenp, activep);
        return activep;
    }

    // CONSTRUCTORS
    ActiveNamer() = default;
-    virtual ~ActiveNamer() override = default;
+    ~ActiveNamer() override = default;
    void main(AstScope* nodep) { iterate(nodep); }
 };

 //######################################################################
 // Latch checking visitor

-class ActiveLatchCheckVisitor final : public ActiveBaseVisitor {
+class ActiveLatchCheckVisitor final : public VNVisitor {
 private:
    // NODE STATE
    // Input:
@@ -303,25 +286,25 @@ private:
    // STATE
    LatchDetectGraph m_graph;  // Graph used to detect latches in combo always
    // VISITORS
-    virtual void visit(AstVarRef* nodep) {
+    void visit(AstVarRef* nodep) override {
        const AstVar* const varp = nodep->varp();
        if (nodep->access().isWriteOrRW() && varp->isSignal() && !varp->isUsedLoopIdx()) {
            m_graph.addAssignment(nodep);
        }
    }
-    virtual void visit(AstNodeIf* nodep) {
+    void visit(AstNodeIf* nodep) override {
        if (!nodep->isBoundsCheck()) {
            LatchDetectGraphVertex* const parentp = m_graph.currentp();
            LatchDetectGraphVertex* const branchp = m_graph.addPathVertex(parentp, "BRANCH", true);
            m_graph.addPathVertex(branchp, "IF");
-            iterateAndNextNull(nodep->ifsp());
+            iterateAndNextNull(nodep->thensp());
            m_graph.addPathVertex(branchp, "ELSE");
            iterateAndNextNull(nodep->elsesp());
            m_graph.currentp(parentp);
        }
    }
    //--------------------
-    virtual void visit(AstNode* nodep) { iterateChildren(nodep); }
+    void visit(AstNode* nodep) override { iterateChildren(nodep); }

 public:
    // CONSTRUCTORS
@@ -330,88 +313,83 @@ public:
        iterate(nodep);
        m_graph.latchCheck(nodep, kwd == VAlwaysKwd::ALWAYS_LATCH);
    }
-    virtual ~ActiveLatchCheckVisitor() {}
+    ~ActiveLatchCheckVisitor() override = default;
 };

 //######################################################################
-// Active AssignDly replacement functions
+// Replace unsupported non-blocking assignments with blocking assignments

-class ActiveDlyVisitor final : public ActiveBaseVisitor {
+class ActiveDlyVisitor final : public VNVisitor {
 public:
-    enum CheckType : uint8_t { CT_SEQ, CT_COMBO, CT_INITIAL, CT_LATCH };
+    enum CheckType : uint8_t { CT_SEQ, CT_COMB, CT_INITIAL };

 private:
-    const CheckType m_check;  // Combo logic or other
-    const AstNode* const m_alwaysp;  // Always we're under
-    const AstNode* m_assignp = nullptr;  // In assign
+    // MEMBERS
+    const CheckType m_check;  // Process type we are checking
+
    // VISITORS
-    virtual void visit(AstAssignDly* nodep) override {
-        if (m_check != CT_SEQ) {
-            // Convert to a non-delayed assignment
-            UINFO(5, "    ASSIGNDLY " << nodep << endl);
-            if (m_check == CT_INITIAL) {
-                nodep->v3warn(INITIALDLY, "Delayed assignments (<=) in initial or final block\n"
-                                              << nodep->warnMore()
-                                              << "... Suggest blocking assignments (=)");
-            } else if (m_check == CT_LATCH) {
-                // Suppress. Shouldn't matter that the interior of the latch races
-            } else if (!(VN_IS(nodep->lhsp(), VarRef)
-                         && VN_AS(nodep->lhsp(), VarRef)->varp()->isLatched())) {
-                nodep->v3warn(COMBDLY, "Delayed assignments (<=) in non-clocked"
-                                       " (non flop or latch) block\n"
-                                           << nodep->warnMore()
-                                           << "... Suggest blocking assignments (=)");
-                // Conversely, we could also suggest latches use delayed assignments, as
-                // recommended by Cliff Cummings?
-            }
-            AstNode* const newp = new AstAssign(nodep->fileline(), nodep->lhsp()->unlinkFrBack(),
-                                                nodep->rhsp()->unlinkFrBack());
-            nodep->replaceWith(newp);
-            VL_DO_DANGLING(nodep->deleteTree(), nodep);
+    void visit(AstAssignDly* nodep) override {
+        // Non-blocking assignments are OK in sequential processes
+        if (m_check == CT_SEQ) return;
+
+        // Issue appropriate warning
+        if (m_check == CT_INITIAL) {
+            nodep->v3warn(INITIALDLY,
+                          "Non-blocking assignment '<=' in initial/final block\n"
+                              << nodep->warnMore()
+                              << "... This will be executed as a blocking assignment '='!");
+        } else {
+            nodep->v3warn(COMBDLY,
+                          "Non-blocking assignment '<=' in combinational logic process\n"
+                              << nodep->warnMore()
+                              << "... This will be executed as a blocking assignment '='!");
        }
+
+        // Convert to blocking assignment
+        nodep->replaceWith(new AstAssign{nodep->fileline(),  //
+                                         nodep->lhsp()->unlinkFrBack(),  //
+                                         nodep->rhsp()->unlinkFrBack()});
+        VL_DO_DANGLING(nodep->deleteTree(), nodep);
    }
-    virtual void visit(AstAssign* nodep) override {
-        if (m_check == CT_SEQ) {
-            VL_RESTORER(m_assignp);
-            m_assignp = nodep;
-            iterateAndNextNull(nodep->lhsp());
-        }
-    }
-    virtual void visit(AstVarRef* nodep) override {
-        const AstVar* const varp = nodep->varp();
-        if (m_check == CT_SEQ && m_assignp && !varp->isUsedLoopIdx()  // Ignore loop indices
-            && !varp->isTemp()) {
-            // Allow turning off warnings on the always, or the variable also
-            if (!m_alwaysp->fileline()->warnIsOff(V3ErrorCode::BLKSEQ)
-                && !m_assignp->fileline()->warnIsOff(V3ErrorCode::BLKSEQ)
-                && !varp->fileline()->warnIsOff(V3ErrorCode::BLKSEQ)) {
-                m_assignp->v3warn(BLKSEQ,
-                                  "Blocking assignments (=) in sequential (flop or latch) block\n"
-                                      << m_assignp->warnMore()
-                                      << "... Suggest delayed assignments (<=)");
-                m_alwaysp->fileline()->modifyWarnOff(
-                    V3ErrorCode::BLKSEQ, true);  // Complain just once for the entire always
-                varp->fileline()->modifyWarnOff(V3ErrorCode::BLKSEQ, true);
-            }
-        }
+
+    void visit(AstAssign* nodep) override {
+        // Blocking assignments are always OK in combinational (and initial/final) processes
+        if (m_check != CT_SEQ) return;
+
+        const bool ignore = nodep->lhsp()->forall<AstVarRef>([&](const AstVarRef* refp) {
+            // Ignore reads (e.g.: index expressions)
+            if (refp->access().isReadOnly()) return true;
+            const AstVar* const varp = refp->varp();
+            // Ignore ...
+            return varp->isUsedLoopIdx()  // ... loop indices
+                   || varp->isTemp()  // ... temporaries
+                   || varp->fileline()->warnIsOff(V3ErrorCode::BLKSEQ);  // ... user said so
+        });
+
+        if (ignore) return;
+
+        nodep->v3warn(BLKSEQ,
+                      "Blocking assignment '=' in sequential logic process\n"
+                          << nodep->warnMore()  //
+                          << "... Suggest using delayed assignment '<='");
    }
+
    //--------------------
-    virtual void visit(AstNode* nodep) override { iterateChildren(nodep); }
+    void visit(AstNode* nodep) override { iterateChildren(nodep); }

 public:
    // CONSTRUCTORS
    ActiveDlyVisitor(AstNode* nodep, CheckType check)
-        : m_check{check}
-        , m_alwaysp{nodep} {
+        : m_check{check} {
        iterate(nodep);
    }
-    virtual ~ActiveDlyVisitor() override = default;
+    ~ActiveDlyVisitor() override = default;
 };

 //######################################################################
 // Active class functions

-class ActiveVisitor final : public ActiveBaseVisitor {
+class ActiveVisitor final : public VNVisitor {
 private:
    // NODE STATE
    //  Each call to V3Const::constify
@@ -424,7 +402,7 @@ private:
    bool m_itemSequent = false;  // Found a SenItem sequential

    // VISITORS
-    virtual void visit(AstScope* nodep) override {
+    void visit(AstScope* nodep) override {
        // Create required actives and add to scope
        UINFO(4, " SCOPE   " << nodep << endl);
        // Clear last scope's names, and collect this scope's existing names
@@ -432,10 +410,10 @@ private:
        m_scopeFinalp = nullptr;
        iterateChildren(nodep);
    }
-    virtual void visit(AstActive* nodep) override {
+    void visit(AstActive* nodep) override {
        // Actives are being formed, so we can ignore any already made
    }
-    virtual void visit(AstInitial* nodep) override {
+    void visit(AstInitialStatic* nodep) override {
        // Relink to IACTIVE, unless already under it
        UINFO(4, "    INITIAL " << nodep << endl);
        const ActiveDlyVisitor dlyvisitor{nodep, ActiveDlyVisitor::CT_INITIAL};
@@ -443,31 +421,39 @@ private:
        nodep->unlinkFrBack();
        wantactivep->addStmtsp(nodep);
    }
-    virtual void visit(AstAssignAlias* nodep) override {
+    void visit(AstInitial* nodep) override {
+        // Relink to IACTIVE, unless already under it
+        UINFO(4, "    INITIAL " << nodep << endl);
+        const ActiveDlyVisitor dlyvisitor{nodep, ActiveDlyVisitor::CT_INITIAL};
+        AstActive* const wantactivep = m_namer.getIActive(nodep->fileline());
+        nodep->unlinkFrBack();
+        wantactivep->addStmtsp(nodep);
+    }
+    void visit(AstAssignAlias* nodep) override {
        // Relink to CACTIVE, unless already under it
        UINFO(4, "    ASSIGNW " << nodep << endl);
        AstActive* const wantactivep = m_namer.getCActive(nodep->fileline());
        nodep->unlinkFrBack();
        wantactivep->addStmtsp(nodep);
    }
-    virtual void visit(AstAssignW* nodep) override {
+    void visit(AstAssignW* nodep) override {
        // Relink to CACTIVE, unless already under it
        UINFO(4, "    ASSIGNW " << nodep << endl);
        AstActive* const wantactivep = m_namer.getCActive(nodep->fileline());
        nodep->unlinkFrBack();
        wantactivep->addStmtsp(nodep);
    }
-    virtual void visit(AstCoverToggle* nodep) override {
+    void visit(AstCoverToggle* nodep) override {
        // Relink to CACTIVE, unless already under it
        UINFO(4, "    COVERTOGGLE " << nodep << endl);
        AstActive* const wantactivep = m_namer.getCActive(nodep->fileline());
        nodep->unlinkFrBack();
        wantactivep->addStmtsp(nodep);
    }
-    virtual void visit(AstFinal* nodep) override {
+    void visit(AstFinal* nodep) override {
        // Relink to CFUNC for the final
        UINFO(4, "    FINAL " << nodep << endl);
-        if (!nodep->bodysp()) {  // Empty, Kill it.
+        if (!nodep->stmtsp()) {  // Empty, Kill it.
            VL_DO_DANGLING(nodep->unlinkFrBack()->deleteTree(), nodep);
            return;
        }
@@ -476,14 +462,14 @@ private:
            m_scopeFinalp = new AstCFunc(
                nodep->fileline(), "_final_" + m_namer.scopep()->nameDotless(), m_namer.scopep());
            m_scopeFinalp->dontCombine(true);
-            m_scopeFinalp->formCallTree(true);
+            m_scopeFinalp->isFinal(true);
            m_scopeFinalp->isStatic(false);
            m_scopeFinalp->isLoose(true);
            m_scopeFinalp->slow(true);
-            m_namer.scopep()->addActivep(m_scopeFinalp);
+            m_namer.scopep()->addBlocksp(m_scopeFinalp);
        }
        nodep->unlinkFrBack();
-        m_scopeFinalp->addStmtsp(nodep->bodysp()->unlinkFrBackWithNext());
+        m_scopeFinalp->addStmtsp(nodep->stmtsp()->unlinkFrBackWithNext());
        VL_DO_DANGLING(nodep->deleteTree(), nodep);
    }

@@ -540,43 +526,39 @@ private:

        // Warn and/or convert any delayed assignments
        if (combo && !sequent) {
+            { ActiveDlyVisitor{nodep, ActiveDlyVisitor::CT_COMB}; }
            const ActiveLatchCheckVisitor latchvisitor{nodep, kwd};
-            if (kwd == VAlwaysKwd::ALWAYS_LATCH) {
-                ActiveDlyVisitor{nodep, ActiveDlyVisitor::CT_LATCH};
-            } else {
-                ActiveDlyVisitor{nodep, ActiveDlyVisitor::CT_COMBO};
-            }
        } else if (!combo && sequent) {
            ActiveDlyVisitor{nodep, ActiveDlyVisitor::CT_SEQ};
        }
    }
-    virtual void visit(AstAlways* nodep) override {
+    void visit(AstAlways* nodep) override {
        // Move always to appropriate ACTIVE based on its sense list
        UINFO(4, "    ALW   " << nodep << endl);
        // if (debug() >= 9) nodep->dumpTree(cout, "  Alw: ");

-        if (!nodep->bodysp()) {
+        if (!nodep->stmtsp()) {
            // Empty always.  Kill it.
            VL_DO_DANGLING(nodep->unlinkFrBack()->deleteTree(), nodep);
            return;
        }
        visitAlways(nodep, nodep->sensesp(), nodep->keyword());
    }
-    virtual void visit(AstAlwaysPostponed* nodep) override {
+    void visit(AstAlwaysPostponed* nodep) override {
        UINFO(4, "    ALW   " << nodep << endl);
-        if (!nodep->bodysp()) {
+        if (!nodep->stmtsp()) {
            VL_DO_DANGLING(nodep->unlinkFrBack()->deleteTree(), nodep);
            return;
        }
        visitAlways(nodep, nullptr, VAlwaysKwd::ALWAYS);
    }
-    virtual void visit(AstAlwaysPublic* nodep) override {
+    void visit(AstAlwaysPublic* nodep) override {
        // Move always to appropriate ACTIVE based on its sense list
        UINFO(4, "    ALWPub   " << nodep << endl);
        // if (debug() >= 9) nodep->dumpTree(cout, "  Alw: ");
        visitAlways(nodep, nodep->sensesp(), VAlwaysKwd::ALWAYS);
    }
-    virtual void visit(AstSenItem* nodep) override {
+    void visit(AstSenItem* nodep) override {
        if (nodep->varrefp()) {
            if (const AstBasicDType* const basicp = nodep->varrefp()->dtypep()->basicp()) {
                if (basicp->isEventValue()) {
@@ -605,14 +587,14 @@ private:
    }

    //--------------------
-    virtual void visit(AstNodeMath*) override {}  // Accelerate
-    virtual void visit(AstVarScope*) override {}  // Accelerate
-    virtual void visit(AstNode* nodep) override { iterateChildren(nodep); }
+    void visit(AstNodeMath*) override {}  // Accelerate
+    void visit(AstVarScope*) override {}  // Accelerate
+    void visit(AstNode* nodep) override { iterateChildren(nodep); }

 public:
    // CONSTRUCTORS
    explicit ActiveVisitor(AstNetlist* nodep) { iterate(nodep); }
-    virtual ~ActiveVisitor() override = default;
+    ~ActiveVisitor() override = default;
 };

 //######################################################################
@@ -621,5 +603,5 @@ public:
 void V3Active::activeAll(AstNetlist* nodep) {
    UINFO(2, __FUNCTION__ << ": " << endl);
    { ActiveVisitor{nodep}; }  // Destruct before checking
-    V3Global::dumpCheckGlobalTree("active", 0, v3Global.opt.dumpTreeLevel(__FILE__) >= 3);
+    V3Global::dumpCheckGlobalTree("active", 0, dumpTree() >= 3);
 }
@@ -26,11 +26,14 @@
 #include "config_build.h"
 #include "verilatedos.h"

-#include "V3Global.h"
 #include "V3ActiveTop.h"
+
 #include "V3Ast.h"
-#include "V3SenTree.h"
 #include "V3Const.h"
+#include "V3Global.h"
+#include "V3SenTree.h"
+
+VL_DEFINE_DEBUG_FUNCTIONS;

 //######################################################################
 // Active class functions
@@ -48,16 +51,15 @@ private:
    SenTreeFinder m_finder;  // Find global sentree's / add them under the AstTopScope

    // METHODS
-    VL_DEBUG_FUNC;  // Declare debug()

    // VISITORS
-    virtual void visit(AstNodeModule* nodep) override {
+    void visit(AstNodeModule* nodep) override {
        // Create required actives and add to module
        // We can start ordering at a module, or a scope
        UINFO(4, " MOD   " << nodep << endl);
        iterateChildren(nodep);
    }
-    virtual void visit(AstActive* nodep) override {
+    void visit(AstActive* nodep) override {
        UINFO(4, "   ACTIVE " << nodep << endl);
        // Remove duplicate clocks and such; sensesp() may change!
        V3Const::constifyExpensiveEdit(nodep);
@@ -100,27 +102,27 @@ private:
        // No need to do statements under it, they're already moved.
        // iterateChildren(nodep);
    }
-    virtual void visit(AstNodeProcedure* nodep) override {  // LCOV_EXCL_LINE
+    void visit(AstNodeProcedure* nodep) override {  // LCOV_EXCL_LINE
        nodep->v3fatalSrc("Node should have been under ACTIVE");
    }
-    virtual void visit(AstAssignAlias* nodep) override {  // LCOV_EXCL_LINE
+    void visit(AstAssignAlias* nodep) override {  // LCOV_EXCL_LINE
        nodep->v3fatalSrc("Node should have been under ACTIVE");
    }
-    virtual void visit(AstAssignW* nodep) override {  // LCOV_EXCL_LINE
+    void visit(AstAssignW* nodep) override {  // LCOV_EXCL_LINE
        nodep->v3fatalSrc("Node should have been under ACTIVE");
    }
-    virtual void visit(AstAlwaysPublic* nodep) override {  // LCOV_EXCL_LINE
+    void visit(AstAlwaysPublic* nodep) override {  // LCOV_EXCL_LINE
        nodep->v3fatalSrc("Node should have been under ACTIVE");
    }
    //--------------------
-    virtual void visit(AstNodeMath*) override {}  // Accelerate
-    virtual void visit(AstVarScope*) override {}  // Accelerate
-    virtual void visit(AstNode* nodep) override { iterateChildren(nodep); }
+    void visit(AstNodeMath*) override {}  // Accelerate
+    void visit(AstVarScope*) override {}  // Accelerate
+    void visit(AstNode* nodep) override { iterateChildren(nodep); }

 public:
    // CONSTRUCTORS
    explicit ActiveTopVisitor(AstNetlist* nodep) { iterate(nodep); }
-    virtual ~ActiveTopVisitor() override = default;
+    ~ActiveTopVisitor() override = default;
 };

 //######################################################################
@@ -129,5 +131,5 @@ public:
 void V3ActiveTop::activeTopAll(AstNetlist* nodep) {
    UINFO(2, __FUNCTION__ << ": " << endl);
    { ActiveTopVisitor{nodep}; }  // Destruct before checking
-    V3Global::dumpCheckGlobalTree("activetop", 0, v3Global.opt.dumpTreeLevel(__FILE__) >= 3);
+    V3Global::dumpCheckGlobalTree("activetop", 0, dumpTree() >= 3);
 }
@@ -17,11 +17,14 @@
 #include "config_build.h"
 #include "verilatedos.h"

-#include "V3Global.h"
 #include "V3Assert.h"
+
 #include "V3Ast.h"
+#include "V3Global.h"
 #include "V3Stats.h"

+VL_DEFINE_DEBUG_FUNCTIONS;
+
 //######################################################################
 // Assert class functions

@@ -69,7 +72,7 @@ private:
        if (!m_monitorNumVarp) {
            m_monitorNumVarp = new AstVar{nodep->fileline(), VVarType::MODULETEMP, "__VmonitorNum",
                                          nodep->findUInt64DType()};
-            v3Global.rootp()->dollarUnitPkgAddp()->addStmtp(m_monitorNumVarp);
+            v3Global.rootp()->dollarUnitPkgAddp()->addStmtsp(m_monitorNumVarp);
        }
        const auto varrefp = new AstVarRef(nodep->fileline(), m_monitorNumVarp, access);
        varrefp->classOrPackagep(v3Global.rootp()->dollarUnitPkgAddp());
@@ -79,7 +82,7 @@ private:
        if (!m_monitorOffVarp) {
            m_monitorOffVarp = new AstVar{nodep->fileline(), VVarType::MODULETEMP, "__VmonitorOff",
                                          nodep->findBitDType()};
-            v3Global.rootp()->dollarUnitPkgAddp()->addStmtp(m_monitorOffVarp);
+            v3Global.rootp()->dollarUnitPkgAddp()->addStmtsp(m_monitorOffVarp);
        }
        const auto varrefp = new AstVarRef(nodep->fileline(), m_monitorOffVarp, access);
        varrefp->classOrPackagep(v3Global.rootp()->dollarUnitPkgAddp());
@@ -98,7 +101,7 @@ private:
                      ? static_cast<AstNode*>(
                          new AstCMath(fl, "vlSymsp->_vm_contextp__->assertOn()", 1))
                      : static_cast<AstNode*>(new AstConst(fl, AstConst::BitFalse())))),
-            nodep, nullptr);
+            nodep);
        newp->user1(true);  // Don't assert/cover this if
        return newp;
    }
@@ -146,7 +149,7 @@ private:
                selfDestruct = true;
            } else {
                // V3Coverage assigned us a bucket to increment.
-                AstCoverInc* const covincp = VN_AS(snodep->coverincp(), CoverInc);
+                AstCoverInc* const covincp = VN_AS(snodep->coverincsp(), CoverInc);
                UASSERT_OBJ(covincp, snodep, "Missing AstCoverInc under assertion");
                covincp->unlinkFrBackWithNext();  // next() might have  AstAssign for trace
                if (message != "") covincp->declp()->comment(message);
@@ -154,7 +157,7 @@ private:
            }

            if (bodysp && passsp) bodysp = bodysp->addNext(passsp);
-            ifp = new AstIf(nodep->fileline(), propp, bodysp, nullptr);
+            ifp = new AstIf(nodep->fileline(), propp, bodysp);
            bodysp = ifp;
        } else if (VN_IS(nodep, Assert) || VN_IS(nodep, AssertIntrinsic)) {
            if (nodep->immediate()) {
@@ -195,7 +198,7 @@ private:
    }

    // VISITORS
-    virtual void visit(AstIf* nodep) override {
+    void visit(AstIf* nodep) override {
        if (nodep->user1SetOnce()) return;
        if (nodep->uniquePragma() || nodep->unique0Pragma()) {
            const AstNodeIf* ifp = nodep;
@@ -208,7 +211,7 @@ private:
                iterateAndNextNull(ifp->condp());

                // Recurse into the true case.
-                iterateAndNextNull(ifp->ifsp());
+                iterateAndNextNull(ifp->thensp());

                // If the last else is not an else if, recurse into that too.
                if (ifp->elsesp() && !nextifp) {  //
@@ -253,7 +256,7 @@ private:
    }

    //========== Case assertions
-    virtual void visit(AstCase* nodep) override {
+    void visit(AstCase* nodep) override {
        iterateChildren(nodep);
        if (!nodep->user1SetOnce()) {
            bool has_default = false;
@@ -262,7 +265,7 @@ private:
                if (itemp->isDefault()) has_default = true;
            }
            if (nodep->fullPragma() || nodep->priorityPragma()) {
-                // Simply need to add a default if there isn't one already
+                // Need to add a default if there isn't one already
                ++m_statAsFull;
                if (!has_default) {
                    nodep->addItemsp(new AstCaseItem(
@@ -313,8 +316,7 @@ private:
                    AstIf* const ifp = new AstIf(
                        nodep->fileline(), new AstLogNot(nodep->fileline(), ohot),
                        newFireAssert(nodep,
-                                      "synthesis parallel_case, but multiple matches found"),
-                        nullptr);
+                                      "synthesis parallel_case, but multiple matches found"));
                    ifp->branchPred(VBranchPred::BP_UNLIKELY);
                    nodep->addNotParallelp(ifp);
                }
@@ -323,7 +325,7 @@ private:
    }

    //========== Past
-    virtual void visit(AstPast* nodep) override {
+    void visit(AstPast* nodep) override {
        iterateChildren(nodep);
        uint32_t ticks = 1;
        if (nodep->ticksp()) {
@@ -338,28 +340,28 @@ private:
        sentreep->unlinkFrBack();
        AstAlways* const alwaysp
            = new AstAlways(nodep->fileline(), VAlwaysKwd::ALWAYS, sentreep, nullptr);
-        m_modp->addStmtp(alwaysp);
+        m_modp->addStmtsp(alwaysp);
        for (uint32_t i = 0; i < ticks; ++i) {
            AstVar* const outvarp = new AstVar(
                nodep->fileline(), VVarType::MODULETEMP,
                "_Vpast_" + cvtToStr(m_modPastNum++) + "_" + cvtToStr(i), inp->dtypep());
-            m_modp->addStmtp(outvarp);
+            m_modp->addStmtsp(outvarp);
            AstNode* const assp = new AstAssignDly(
                nodep->fileline(), new AstVarRef(nodep->fileline(), outvarp, VAccess::WRITE), inp);
-            alwaysp->addStmtp(assp);
+            alwaysp->addStmtsp(assp);
            // if (debug() >= 9) assp->dumpTree(cout, "-ass: ");
            invarp = outvarp;
            inp = new AstVarRef(nodep->fileline(), invarp, VAccess::READ);
        }
        nodep->replaceWith(inp);
    }
-    virtual void visit(AstSampled* nodep) override {
+    void visit(AstSampled* nodep) override {
        nodep->replaceWith(nodep->exprp()->unlinkFrBack());
        VL_DO_DANGLING(pushDeletep(nodep), nodep);
    }

    //========== Statements
-    virtual void visit(AstDisplay* nodep) override {
+    void visit(AstDisplay* nodep) override {
        iterateChildren(nodep);
        // Replace the special types with standard text
        if (nodep->displayType() == VDisplayType::DT_INFO) {
@@ -384,10 +386,10 @@ private:
                new AstLogAnd{fl, new AstLogNot{fl, newMonitorOffVarRefp(nodep, VAccess::READ)},
                              new AstEq{fl, new AstConst{fl, monNum},
                                        newMonitorNumVarRefp(nodep, VAccess::READ)}},
-                stmtsp, nullptr};
+                stmtsp};
            ifp->branchPred(VBranchPred::BP_UNLIKELY);
            AstNode* const newp = new AstAlwaysPostponed{fl, ifp};
-            m_modp->addStmtp(newp);
+            m_modp->addStmtsp(newp);
        } else if (nodep->displayType() == VDisplayType::DT_STROBE) {
            nodep->displayType(VDisplayType::DT_DISPLAY);
            // Need one-shot
@@ -395,48 +397,47 @@ private:
            const auto varp
                = new AstVar{fl, VVarType::MODULETEMP, "__Vstrobe" + cvtToStr(m_modStrobeNum++),
                             nodep->findBitDType()};
-            m_modp->addStmtp(varp);
+            m_modp->addStmtsp(varp);
            // Where $strobe was we do "__Vstrobe = '1;"
            const auto newsetp = new AstAssign{fl, new AstVarRef{fl, varp, VAccess::WRITE},
                                               new AstConst{fl, AstConst::BitTrue{}}};
            nodep->replaceWith(newsetp);
            // Add "always_comb if (__Vstrobe) begin $display(...); __Vstrobe = '0; end"
            AstNode* const stmtsp = nodep;
-            AstIf* const ifp
-                = new AstIf{fl, new AstVarRef{fl, varp, VAccess::READ}, stmtsp, nullptr};
+            AstIf* const ifp = new AstIf{fl, new AstVarRef{fl, varp, VAccess::READ}, stmtsp};
            ifp->branchPred(VBranchPred::BP_UNLIKELY);
            AstNode* const newp = new AstAlwaysPostponed{fl, ifp};
            stmtsp->addNext(new AstAssign{fl, new AstVarRef{fl, varp, VAccess::WRITE},
                                          new AstConst{fl, AstConst::BitFalse{}}});
-            m_modp->addStmtp(newp);
+            m_modp->addStmtsp(newp);
        }
    }
-    virtual void visit(AstMonitorOff* nodep) override {
+    void visit(AstMonitorOff* nodep) override {
        const auto newp
            = new AstAssign(nodep->fileline(), newMonitorOffVarRefp(nodep, VAccess::WRITE),
                            new AstConst(nodep->fileline(), AstConst::BitTrue{}, nodep->off()));
        nodep->replaceWith(newp);
        VL_DO_DANGLING(pushDeletep(nodep), nodep);
    }
-    virtual void visit(AstAssert* nodep) override {
+    void visit(AstAssert* nodep) override {
        iterateChildren(nodep);
        newPslAssertion(nodep, nodep->failsp());
    }
-    virtual void visit(AstAssertIntrinsic* nodep) override {
+    void visit(AstAssertIntrinsic* nodep) override {
        iterateChildren(nodep);
        newPslAssertion(nodep, nodep->failsp());
    }
-    virtual void visit(AstCover* nodep) override {
+    void visit(AstCover* nodep) override {
        iterateChildren(nodep);
        newPslAssertion(nodep, nullptr);
    }
-    virtual void visit(AstRestrict* nodep) override {
+    void visit(AstRestrict* nodep) override {
        iterateChildren(nodep);
        // IEEE says simulator ignores these
        VL_DO_DANGLING(pushDeletep(nodep->unlinkFrBack()), nodep);
    }

-    virtual void visit(AstNodeModule* nodep) override {
+    void visit(AstNodeModule* nodep) override {
        VL_RESTORER(m_modp);
        VL_RESTORER(m_modPastNum);
        VL_RESTORER(m_modStrobeNum);
@@ -447,7 +448,7 @@ private:
            iterateChildren(nodep);
        }
    }
-    virtual void visit(AstBegin* nodep) override {
+    void visit(AstBegin* nodep) override {
        // This code is needed rather than a visitor in V3Begin,
        // because V3Assert is called before V3Begin
        VL_RESTORER(m_beginp);
@@ -457,12 +458,12 @@ private:
        }
    }

-    virtual void visit(AstNode* nodep) override { iterateChildren(nodep); }
+    void visit(AstNode* nodep) override { iterateChildren(nodep); }

 public:
    // CONSTRUCTORS
    explicit AssertVisitor(AstNetlist* nodep) { iterate(nodep); }
-    virtual ~AssertVisitor() override {
+    ~AssertVisitor() override {
        V3Stats::addStat("Assertions, assert non-immediate statements", m_statAsNotImm);
        V3Stats::addStat("Assertions, assert immediate statements", m_statAsImm);
        V3Stats::addStat("Assertions, cover statements", m_statCover);
@@ -476,5 +477,5 @@ public:
 void V3Assert::assertAll(AstNetlist* nodep) {
    UINFO(2, __FUNCTION__ << ": " << endl);
    { AssertVisitor{nodep}; }  // Destruct before checking
-    V3Global::dumpCheckGlobalTree("assert", 0, v3Global.opt.dumpTreeLevel(__FILE__) >= 3);
+    V3Global::dumpCheckGlobalTree("assert", 0, dumpTree() >= 3);
 }
@@ -20,8 +20,8 @@
 #include "config_build.h"
 #include "verilatedos.h"

-#include "V3Error.h"
 #include "V3Ast.h"
+#include "V3Error.h"

 //============================================================================

@@ -20,9 +20,12 @@
 #include "config_build.h"
 #include "verilatedos.h"

-#include "V3Global.h"
 #include "V3AssertPre.h"
+
 #include "V3Ast.h"
+#include "V3Global.h"
+
+VL_DEFINE_DEBUG_FUNCTIONS;

 //######################################################################
 // Assert class functions
@@ -44,7 +47,6 @@ private:
    AstNode* m_disablep = nullptr;  // Last disable

    // METHODS
-    VL_DEBUG_FUNC;  // Declare debug()

    AstSenTree* newSenTree(AstNode* nodep) {
        // Create sentree based on clocked or default clock
@@ -68,7 +70,7 @@ private:

    // VISITORS
    //========== Statements
-    virtual void visit(AstClocking* nodep) override {
+    void visit(AstClocking* nodep) override {
        UINFO(8, "   CLOCKING" << nodep << endl);
        // Store the new default clock, reset on new module
        m_seniDefaultp = nodep->sensesp();
@@ -80,14 +82,14 @@ private:
        }
        VL_DO_DANGLING(pushDeletep(nodep), nodep);
    }
-    virtual void visit(AstAlways* nodep) override {
+    void visit(AstAlways* nodep) override {
        iterateAndNextNull(nodep->sensesp());
        if (nodep->sensesp()) m_seniAlwaysp = nodep->sensesp()->sensesp();
-        iterateAndNextNull(nodep->bodysp());
+        iterateAndNextNull(nodep->stmtsp());
        m_seniAlwaysp = nullptr;
    }

-    virtual void visit(AstNodeCoverOrAssert* nodep) override {
+    void visit(AstNodeCoverOrAssert* nodep) override {
        if (nodep->sentreep()) return;  // Already processed
        clearAssertInfo();
        // Find Clocking's buried under nodep->exprsp
@@ -95,7 +97,7 @@ private:
        if (!nodep->immediate()) nodep->sentreep(newSenTree(nodep));
        clearAssertInfo();
    }
-    virtual void visit(AstFell* nodep) override {
+    void visit(AstFell* nodep) override {
        if (nodep->sentreep()) return;  // Already processed
        iterateChildren(nodep);
        FileLine* const fl = nodep->fileline();
@@ -109,12 +111,12 @@ private:
        nodep->sentreep(newSenTree(nodep));
        VL_DO_DANGLING(pushDeletep(nodep), nodep);
    }
-    virtual void visit(AstPast* nodep) override {
+    void visit(AstPast* nodep) override {
        if (nodep->sentreep()) return;  // Already processed
        iterateChildren(nodep);
        nodep->sentreep(newSenTree(nodep));
    }
-    virtual void visit(AstRose* nodep) override {
+    void visit(AstRose* nodep) override {
        if (nodep->sentreep()) return;  // Already processed
        iterateChildren(nodep);
        FileLine* const fl = nodep->fileline();
@@ -128,7 +130,7 @@ private:
        nodep->sentreep(newSenTree(nodep));
        VL_DO_DANGLING(pushDeletep(nodep), nodep);
    }
-    virtual void visit(AstStable* nodep) override {
+    void visit(AstStable* nodep) override {
        if (nodep->sentreep()) return;  // Already processed
        iterateChildren(nodep);
        FileLine* const fl = nodep->fileline();
@@ -142,7 +144,7 @@ private:
        VL_DO_DANGLING(pushDeletep(nodep), nodep);
    }

-    virtual void visit(AstImplication* nodep) override {
+    void visit(AstImplication* nodep) override {
        if (nodep->sentreep()) return;  // Already processed

        FileLine* const fl = nodep->fileline();
@@ -160,23 +162,21 @@ private:
        VL_DO_DANGLING(pushDeletep(nodep), nodep);
    }

-    virtual void visit(AstPropClocked* nodep) override {
+    void visit(AstPropClocked* nodep) override {
        // No need to iterate the body, once replace will get iterated
        iterateAndNextNull(nodep->sensesp());
        if (m_senip)
            nodep->v3warn(E_UNSUPPORTED, "Unsupported: Only one PSL clock allowed per assertion");
        // Block is the new expression to evaluate
        AstNode* blockp = nodep->propp()->unlinkFrBack();
-        if (nodep->disablep()) {
-            m_disablep = nodep->disablep()->cloneTree(false);
+        if (AstNode* const disablep = nodep->disablep()) {
+            m_disablep = disablep->cloneTree(false);
            if (VN_IS(nodep->backp(), Cover)) {
-                blockp = new AstAnd(
-                    nodep->disablep()->fileline(),
-                    new AstNot(nodep->disablep()->fileline(), nodep->disablep()->unlinkFrBack()),
-                    blockp);
+                blockp = new AstAnd(disablep->fileline(),
+                                    new AstNot(disablep->fileline(), disablep->unlinkFrBack()),
+                                    blockp);
            } else {
-                blockp = new AstOr(nodep->disablep()->fileline(),
-                                   nodep->disablep()->unlinkFrBack(), blockp);
+                blockp = new AstOr(disablep->fileline(), disablep->unlinkFrBack(), blockp);
            }
        }
        // Unlink and just keep a pointer to it, convert to sentree as needed
@@ -184,12 +184,12 @@ private:
        nodep->replaceWith(blockp);
        VL_DO_DANGLING(pushDeletep(nodep), nodep);
    }
-    virtual void visit(AstNodeModule* nodep) override {
+    void visit(AstNodeModule* nodep) override {
        iterateChildren(nodep);
        // Reset defaults
        m_seniDefaultp = nullptr;
    }
-    virtual void visit(AstNode* nodep) override { iterateChildren(nodep); }
+    void visit(AstNode* nodep) override { iterateChildren(nodep); }

 public:
    // CONSTRUCTORS
@@ -198,7 +198,7 @@ public:
        // Process
        iterate(nodep);
    }
-    virtual ~AssertPreVisitor() override = default;
+    ~AssertPreVisitor() override = default;
 };

 //######################################################################
@@ -207,5 +207,5 @@ public:
 void V3AssertPre::assertPreAll(AstNetlist* nodep) {
    UINFO(2, __FUNCTION__ << ": " << endl);
    { AssertPreVisitor{nodep}; }  // Destruct before checking
-    V3Global::dumpCheckGlobalTree("assertpre", 0, v3Global.opt.dumpTreeLevel(__FILE__) >= 3);
+    V3Global::dumpCheckGlobalTree("assertpre", 0, dumpTree() >= 3);
 }
@@ -18,20 +18,23 @@
 #include "verilatedos.h"

 #include "V3Ast.h"
-#include "V3File.h"
-#include "V3Global.h"
+
 #include "V3Broken.h"
 #include "V3EmitV.h"
+#include "V3File.h"
+#include "V3Global.h"
 #include "V3String.h"

 #include <iomanip>
 #include <memory>

+VL_DEFINE_DEBUG_FUNCTIONS;
+
 //======================================================================
 // Statics

-vluint64_t AstNode::s_editCntLast = 0;
-vluint64_t AstNode::s_editCntGbl = 0;  // Hot cache line
+uint64_t AstNode::s_editCntLast = 0;
+uint64_t AstNode::s_editCntGbl = 0;  // Hot cache line

 // To allow for fast clearing of all user pointers, we keep a "timestamp"
 // along with each userp, and thus by bumping this count we can make it look
@@ -114,7 +117,7 @@ string AstNode::encodeName(const string& namein) {
    return vname.hashedName();
 }

-string AstNode::encodeNumber(vlsint64_t num) {
+string AstNode::encodeNumber(int64_t num) {
    if (num < 0) {
        return "__02D" + cvtToStr(-num);  // 2D=-
    } else {
@@ -164,22 +167,22 @@ string AstNode::prettyName(const string& namein) {
            continue;
        }
        if (pos[0] == '_' && pos[1] == '_') {  // Short-circuit
-            if (0 == strncmp(pos, "__BRA__", 7)) {
+            if (0 == std::strncmp(pos, "__BRA__", 7)) {
                pretty += "[";
                pos += 7;
                continue;
            }
-            if (0 == strncmp(pos, "__KET__", 7)) {
+            if (0 == std::strncmp(pos, "__KET__", 7)) {
                pretty += "]";
                pos += 7;
                continue;
            }
-            if (0 == strncmp(pos, "__DOT__", 7)) {
+            if (0 == std::strncmp(pos, "__DOT__", 7)) {
                pretty += ".";
                pos += 7;
                continue;
            }
-            if (0 == strncmp(pos, "__PVT__", 7)) {
+            if (0 == std::strncmp(pos, "__PVT__", 7)) {
                pretty += "";
                pos += 7;
                continue;
@@ -205,14 +208,13 @@ string AstNode::prettyName(const string& namein) {

 string AstNode::prettyTypeName() const {
    if (name() == "") return typeName();
-    return string(typeName()) + " '" + prettyName() + "'";
+    return std::string{typeName()} + " '" + prettyName() + "'";
 }

 //######################################################################
 // Insertion

-inline void AstNode::debugTreeChange(const AstNode* nodep, const char* prefix, int lineno,
-                                     bool next){
+void AstNode::debugTreeChange(const AstNode* nodep, const char* prefix, int lineno, bool next) {
 #ifdef VL_DEBUG
 // Called on all major tree changers.
 // Only for use for those really nasty bugs relating to internals
@@ -233,7 +235,8 @@ inline void AstNode::debugTreeChange(const AstNode* nodep, const char* prefix, i
 #endif
 }

-AstNode* AstNode::addNext(AstNode* nodep, AstNode* newp) {
+template <>
+AstNode* AstNode::addNext<AstNode, AstNode>(AstNode* nodep, AstNode* newp) {
    // Add to m_nextp, returns this
    UDEBUGONLY(UASSERT_OBJ(newp, nodep, "Null item passed to addNext"););
    debugTreeChange(nodep, "-addNextThs: ", __LINE__, false);
@@ -271,23 +274,18 @@ AstNode* AstNode::addNext(AstNode* nodep, AstNode* newp) {
    return nodep;
 }

-AstNode* AstNode::addNextNull(AstNode* nodep, AstNode* newp) {
-    if (!newp) return nodep;
-    return addNext(nodep, newp);
-}
-
 void AstNode::addNextHere(AstNode* newp) {
    // Add to m_nextp on exact node passed, not at the end.
    //  This could be at head, tail, or both (single)
    //  New  could be head of single node, or list
    UASSERT(newp, "Null item passed to addNext");
-    UASSERT(!newp->backp(), "New node (back) already assigned?");
+    UASSERT_OBJ(!newp->backp(), newp, "New node (back) already assigned?");
    debugTreeChange(this, "-addHereThs: ", __LINE__, false);
    debugTreeChange(newp, "-addHereNew: ", __LINE__, true);
    newp->editCountInc();

    AstNode* const addlastp = newp->m_headtailp;  // Last node in list to be added
-    UASSERT(!addlastp->m_nextp, "Headtailp tail isn't at the tail");
+    UASSERT_OBJ(!addlastp->m_nextp, addlastp, "Headtailp tail isn't at the tail");

    // Forward links
    AstNode* const oldnextp = this->m_nextp;
@@ -437,7 +435,7 @@ void VNRelinker::dump(std::ostream& str) const {
 AstNode* AstNode::unlinkFrBackWithNext(VNRelinker* linkerp) {
    debugTreeChange(this, "-unlinkWNextThs: ", __LINE__, true);
    AstNode* const oldp = this;
-    UASSERT(oldp->m_backp, "Node has no back, already unlinked?");
+    UASSERT_OBJ(oldp->m_backp, oldp, "Node has no back, already unlinked?");
    oldp->editCountInc();
    AstNode* const backp = oldp->m_backp;
    if (linkerp) {
@@ -497,7 +495,7 @@ AstNode* AstNode::unlinkFrBackWithNext(VNRelinker* linkerp) {
 AstNode* AstNode::unlinkFrBack(VNRelinker* linkerp) {
    debugTreeChange(this, "-unlinkFrBkThs: ", __LINE__, true);
    AstNode* const oldp = this;
-    UASSERT(oldp->m_backp, "Node has no back, already unlinked?");
+    UASSERT_OBJ(oldp->m_backp, oldp, "Node has no back, already unlinked?");
    oldp->editCountInc();
    AstNode* const backp = oldp->m_backp;
    if (linkerp) {
@@ -565,7 +563,7 @@ void AstNode::relink(VNRelinker* linkerp) {
    }
    AstNode* const newp = this;
    UASSERT(linkerp && linkerp->m_backp, "Need non-empty linker");
-    UASSERT(!newp->backp(), "New node already linked?");
+    UASSERT_OBJ(!newp->m_backp, newp, "New node already linked?");
    newp->editCountInc();

    if (debug() > 8) {
@@ -631,11 +629,56 @@ void AstNode::relinkOneLink(AstNode*& pointpr,  // Ref to pointer that gets set
 }

 void AstNode::addHereThisAsNext(AstNode* newp) {
-    // {old}->this->{next} becomes {old}->new->this->{next}
-    VNRelinker handle;
-    this->unlinkFrBackWithNext(&handle);
-    newp->addNext(this);
-    handle.relink(newp);
+    // {back}->this->{next} becomes {back}->new->this->{next}
+    UASSERT_OBJ(!newp->backp(), newp, "New node already linked?");
+    UASSERT_OBJ(this->m_backp, this, "'this' node has no back, already unlinked?");
+    UASSERT_OBJ(newp->m_headtailp, newp, "m_headtailp not set on new node");
+    //
+    AstNode* const backp = this->m_backp;
+    AstNode* const newLastp = newp->m_headtailp;
+    //
+    this->editCountInc();
+    // Common linkage
+    newLastp->m_nextp = this;
+    this->m_backp = newLastp;
+    newp->m_backp = backp;
+    // newLastp will not be the last node in the list as 'this' will follow it.
+    // If newLastp == newp, then below handles newp becoming head
+    newLastp->m_headtailp = nullptr;
+    // Linkage dependent on position
+    if (backp && backp->m_nextp == this) {
+        // If 'this' is not at the head of a list, then the new node will also not be at the head
+        // of a list, so we can just link in the new node in the middle.
+        backp->m_nextp = newp;
+        newp->m_headtailp = nullptr;
+    } else {
+        // If 'this' is at the head of a list, then the new node becomes the head of that list.
+        if (backp) {
+            if (backp->m_op1p == this) {
+                backp->m_op1p = newp;
+            } else if (backp->m_op2p == this) {
+                backp->m_op2p = newp;
+            } else if (backp->m_op3p == this) {
+                backp->m_op3p = newp;
+            } else {
+                UASSERT_OBJ(backp->m_op4p == this, this, "Don't know where newp should go");
+                backp->m_op4p = newp;
+            }
+        }
+        // We also need to update m_headtailp.
+        AstNode* const tailp = this->m_headtailp;
+        this->m_headtailp = nullptr;
+        newp->m_headtailp = tailp;
+        tailp->m_headtailp = newp;
+    }
+    // Iterator fixup
+    if (newLastp->m_iterpp) *(newLastp->m_iterpp) = this;
+    if (this->m_iterpp) {
+        *(this->m_iterpp) = newp;
+        this->m_iterpp = nullptr;
+    }
+    //
+    debugTreeChange(this, "-addHereThisAsNext: ", __LINE__, true);
 }

 void AstNode::swapWith(AstNode* bp) {
@@ -758,7 +801,7 @@ void AstNode::deleteTree() {
 #ifdef VL_LEAK_CHECKS
 void* AstNode::operator new(size_t size) {
    // Optimization note: Aligning to cache line is a loss, due to lost packing
-    const AstNode* const objp = static_cast<AstNode*>(::operator new(size));
+    AstNode* const objp = static_cast<AstNode*>(::operator new(size));
    V3Broken::addNewed(objp);
    return objp;
 }
@@ -879,7 +922,7 @@ AstNode* AstNode::iterateSubtreeReturnEdits(VNVisitor& v) {
    } else if (!nodep->backp()) {
        // Calling on standalone tree; insert a shim node so we can keep
        // track, then delete it on completion
-        AstBegin* const tempp = new AstBegin(nodep->fileline(), "[EditWrapper]", nodep);
+        AstBegin* const tempp = new AstBegin{nodep->fileline(), "[EditWrapper]", nodep};
        {
            VL_DO_DANGLING(tempp->stmtsp()->accept(v),
                           nodep);  // nodep to null as may be replaced
@@ -958,43 +1001,12 @@ bool AstNode::sameTreeIter(const AstNode* node1p, const AstNode* node2p, bool ig
 //======================================================================
 // Debugging

-void AstNode::checkTreeIter(AstNode* backp) {
+void AstNode::checkTreeIter(const AstNode* backp) const {
    // private: Check a tree and children
    UASSERT_OBJ(backp == this->backp(), this, "Back node inconsistent");
-    if (VN_IS(this, NodeTermop) || VN_IS(this, NodeVarRef)) {
-        // Termops have a short-circuited iterateChildren, so check usage
-        UASSERT_OBJ(!(op1p() || op2p() || op3p() || op4p()), this,
-                    "Terminal operation with non-terminals");
-    }
-    if (m_op1p) m_op1p->checkTreeIterList(this);
-    if (m_op2p) m_op2p->checkTreeIterList(this);
-    if (m_op3p) m_op3p->checkTreeIterList(this);
-    if (m_op4p) m_op4p->checkTreeIterList(this);
-}
-
-void AstNode::checkTreeIterList(AstNode* backp) {
-    // private: Check a (possible) list of nodes, this is always the head of the list
-    // Audited to make sure this is never nullptr
-    AstNode* const headp = this;
-    const AstNode* tailp = this;
-    for (AstNode* nodep = headp; nodep; nodep = nodep->nextp()) {
-        nodep->checkTreeIter(backp);
-        UASSERT_OBJ(headp == this || !nextp(), this,
-                    "Headtailp should be null in middle of lists");
-        tailp = nodep;
-        backp = nodep;
-    }
-    UASSERT_OBJ(headp->m_headtailp == tailp, headp, "Tail in headtailp is inconsistent");
-    UASSERT_OBJ(tailp->m_headtailp == headp, tailp, "Head in headtailp is inconsistent");
-}
-
-void AstNode::checkTree() {
-    if (!debug()) return;
-    if (this->backp()) {
-        // Linked tree- check only the passed node
-        this->checkTreeIter(this->backp());
-    } else {
-        this->checkTreeIterList(this->backp());
+    switch (this->type()) {
+#include "V3Ast__gen_op_checks.h"
+    default: VL_UNREACHABLE;  // LCOV_EXCL_LINE
    }
 }

@@ -1110,7 +1122,7 @@ void AstNode::dumpTreeFile(const string& filename, bool append, bool doDump, boo
            if (logsp->fail()) v3fatal("Can't write " << filename);
            *logsp << "Verilator Tree Dump (format 0x3900) from <e" << std::dec << editCountLast();
            *logsp << "> to <e" << std::dec << editCountGbl() << ">\n";
-            if (editCountGbl() == editCountLast() && !(v3Global.opt.dumpTree() >= 9)) {
+            if (editCountGbl() == editCountLast() && ::dumpTree() < 9) {
                *logsp << '\n';
                *logsp << "No changes since last dump!\n";
            } else {
@@ -1120,7 +1132,7 @@ void AstNode::dumpTreeFile(const string& filename, bool append, bool doDump, boo
        }
    }
    if (doDump && v3Global.opt.debugEmitV()) V3EmitV::debugEmitV(filename + ".v");
-    if (doCheck && (v3Global.opt.debugCheck() || v3Global.opt.dumpTree())) {
+    if (doCheck && (v3Global.opt.debugCheck() || ::dumpTree())) {
        // Error check
        checkTree();
        // Broken isn't part of check tree because it can munge iterp's
@@ -1135,49 +1147,33 @@ void AstNode::v3errorEndFatal(std::ostringstream& str) const {
    VL_UNREACHABLE
 }

-string AstNode::locationStr() const {
-    string str = "... In instance ";
-    const AstNode* backp = this;
-    int itmax = 10000;  // Max iterations before giving up on location search
-    while (backp) {
-        if (VL_UNCOVERABLE(--itmax < 0)) {
-            // Likely some circular back link, and V3Ast is trying to report a low-level error
-            UINFO(1, "Ran out of iterations finding locationStr on " << backp << endl);
-            return "";  // LCOV_EXCL_LINE
-        }
-        const AstScope* scopep;
-        if ((scopep = VN_CAST(backp, Scope))) {
-            // The design is flattened and there are no useful scopes
-            // This is probably because of inlining
-            if (scopep->isTop()) break;
+string AstNode::instanceStr() const {
+    // Max iterations before giving up on location search,
+    // in case we have some circular reference bug.
+    constexpr unsigned maxIterations = 10000;
+    unsigned iterCount = 0;

-            str += scopep->prettyName();
-            return str;
+    for (const AstNode* backp = this; backp; backp = backp->backp(), ++iterCount) {
+        if (VL_UNCOVERABLE(iterCount >= maxIterations)) return "";  // LCOV_EXCL_LINE
+
+        // Prefer the enclosing scope, if there is one. This is always under the enclosing module,
+        // so just pick it up when encountered
+        if (const AstScope* const scopep = VN_CAST(backp, Scope)) {
+            return scopep->isTop() ? "" : "... In instance " + scopep->prettyName();
        }
-        backp = backp->backp();
-    }
-    backp = this;
-    while (backp) {
-        const AstModule* modp;
-        const AstNodeVarRef* nvrp;
-        if ((modp = VN_CAST(backp, Module)) && !modp->hierName().empty()) {
-            str += modp->hierName();
-            return str;
-        } else if ((nvrp = VN_CAST(backp, NodeVarRef))) {
-            const string prettyName = nvrp->prettyName();
-            // VarRefs have not been flattened yet and do not contain location information
-            if (prettyName != nvrp->name()) {
-                str += prettyName;
-                return str;
-            }
+
+        // If scopes don't exist, report an example instance of the enclosing module
+        if (const AstModule* const modp = VN_CAST(backp, Module)) {
+            const string instanceName = modp->someInstanceName();
+            return instanceName.empty() ? "" : "... In instance " + instanceName;
        }
-        backp = backp->backp();
    }
+
    return "";
 }
 void AstNode::v3errorEnd(std::ostringstream& str) const {
    if (!m_fileline) {
-        V3Error::v3errorEnd(str, locationStr());
+        V3Error::v3errorEnd(str, instanceStr());
    } else {
        std::ostringstream nsstr;
        nsstr << str.str();
@@ -1187,7 +1183,11 @@ void AstNode::v3errorEnd(std::ostringstream& str) const {
            const_cast<AstNode*>(this)->dump(nsstr);
            nsstr << endl;
        }
-        m_fileline->v3errorEnd(nsstr, locationStr());
+        // Don't look for instance name when warning is disabled.
+        // In case of large number of warnings, this can
+        // take significant amount of time
+        m_fileline->v3errorEnd(nsstr,
+                               m_fileline->warnIsOff(V3Error::errorCode()) ? "" : instanceStr());
    }
 }

@@ -1264,3 +1264,8 @@ void VNDeleter::doDeletes() {
    for (AstNode* const nodep : m_deleteps) nodep->deleteTree();
    m_deleteps.clear();
 }
+
+//######################################################################
+// VNVisitor
+
+#include "V3Ast__gen_visitor_defns.h"  // From ./astgen
@@ -17,71 +17,175 @@
 #ifndef VERILATOR_V3ASTINLINES_H_
 #define VERILATOR_V3ASTINLINES_H_

-#ifndef VERILATOR_V3ASTNODES_H_
+#ifndef VERILATOR_V3AST_H_
 #error "Use V3Ast.h as the include"
-#include "V3AstNodes.h"  // This helps code analysis tools pick up symbols in V3Ast.h and V3AstNodes.h
+#include "V3Ast.h"  // This helps code analysis tools pick up symbols in V3Ast.h and relaed
 #endif

 //######################################################################
-// Inline ACCESSORS
+// Inline METHODS

-inline int AstNode::width() const { return dtypep() ? dtypep()->width() : 0; }
-inline int AstNode::widthMin() const { return dtypep() ? dtypep()->widthMin() : 0; }
-inline bool AstNode::width1() const {  // V3Const uses to know it can optimize
+int AstNode::width() const { return dtypep() ? dtypep()->width() : 0; }
+int AstNode::widthMin() const { return dtypep() ? dtypep()->widthMin() : 0; }
+bool AstNode::width1() const {  // V3Const uses to know it can optimize
    return dtypep() && dtypep()->width() == 1;
 }
-inline int AstNode::widthInstrs() const {
+int AstNode::widthInstrs() const {
    return (!dtypep() ? 1 : (dtypep()->isWide() ? dtypep()->widthWords() : 1));
 }
-inline bool AstNode::isDouble() const {
+bool AstNode::isDouble() const {
    return dtypep() && VN_IS(dtypep(), BasicDType) && VN_AS(dtypep(), BasicDType)->isDouble();
 }
-inline bool AstNode::isString() const {
+bool AstNode::isString() const {
    return dtypep() && dtypep()->basicp() && dtypep()->basicp()->isString();
 }
-inline bool AstNode::isSigned() const { return dtypep() && dtypep()->isSigned(); }
+bool AstNode::isSigned() const { return dtypep() && dtypep()->isSigned(); }

-inline bool AstNode::isZero() const {
+bool AstNode::isZero() const {
    return (VN_IS(this, Const) && VN_AS(this, Const)->num().isEqZero());
 }
-inline bool AstNode::isNeqZero() const {
+bool AstNode::isNeqZero() const {
    return (VN_IS(this, Const) && VN_AS(this, Const)->num().isNeqZero());
 }
-inline bool AstNode::isOne() const {
-    return (VN_IS(this, Const) && VN_AS(this, Const)->num().isEqOne());
-}
-inline bool AstNode::isAllOnes() const {
+bool AstNode::isOne() const { return (VN_IS(this, Const) && VN_AS(this, Const)->num().isEqOne()); }
+bool AstNode::isAllOnes() const {
    return (VN_IS(this, Const) && VN_AS(this, Const)->isEqAllOnes());
 }
-inline bool AstNode::isAllOnesV() const {
+bool AstNode::isAllOnesV() const {
    return (VN_IS(this, Const) && VN_AS(this, Const)->isEqAllOnesV());
 }
-inline bool AstNode::sameTree(const AstNode* node2p) const {
+bool AstNode::sameTree(const AstNode* node2p) const {
    return sameTreeIter(this, node2p, true, false);
 }
-inline bool AstNode::sameGateTree(const AstNode* node2p) const {
+bool AstNode::sameGateTree(const AstNode* node2p) const {
    return sameTreeIter(this, node2p, true, true);
 }

-inline void AstNodeVarRef::varp(AstVar* varp) {
-    m_varp = varp;
+int AstNodeArrayDType::left() const { return rangep()->leftConst(); }
+int AstNodeArrayDType::right() const { return rangep()->rightConst(); }
+int AstNodeArrayDType::hi() const { return rangep()->hiConst(); }
+int AstNodeArrayDType::lo() const { return rangep()->loConst(); }
+int AstNodeArrayDType::elementsConst() const { return rangep()->elementsConst(); }
+VNumRange AstNodeArrayDType::declRange() const { return VNumRange{left(), right()}; }
+
+AstRange::AstRange(FileLine* fl, int left, int right)
+    : ASTGEN_SUPER_Range(fl) {
+    leftp(new AstConst{fl, static_cast<uint32_t>(left)});
+    rightp(new AstConst{fl, static_cast<uint32_t>(right)});
+}
+AstRange::AstRange(FileLine* fl, const VNumRange& range)
+    : ASTGEN_SUPER_Range(fl) {
+    leftp(new AstConst{fl, static_cast<uint32_t>(range.left())});
+    rightp(new AstConst{fl, static_cast<uint32_t>(range.right())});
+}
+int AstRange::leftConst() const {
+    AstConst* const constp = VN_CAST(leftp(), Const);
+    return (constp ? constp->toSInt() : 0);
+}
+int AstRange::rightConst() const {
+    AstConst* const constp = VN_CAST(rightp(), Const);
+    return (constp ? constp->toSInt() : 0);
+}
+
+int AstQueueDType::boundConst() const {
+    AstConst* const constp = VN_CAST(boundp(), Const);
+    return (constp ? constp->toSInt() : 0);
+}
+
+AstPin::AstPin(FileLine* fl, int pinNum, AstVarRef* varname, AstNode* exprp)
+    : ASTGEN_SUPER_Pin(fl)
+    , m_pinNum{pinNum}
+    , m_name{varname->name()} {
+    this->exprp(exprp);
+}
+
+AstDpiExportUpdated::AstDpiExportUpdated(FileLine* fl, AstVarScope* varScopep)
+    : ASTGEN_SUPER_DpiExportUpdated(fl) {
+    this->varRefp(new AstVarRef{fl, varScopep, VAccess::WRITE});
+}
+
+AstVarScope* AstDpiExportUpdated::varScopep() const { return varRefp()->varScopep(); }
+
+AstPackArrayDType::AstPackArrayDType(FileLine* fl, VFlagChildDType, AstNodeDType* dtp,
+                                     AstRange* rangep)
+    : ASTGEN_SUPER_PackArrayDType(fl) {
+    childDTypep(dtp);  // Only for parser
+    refDTypep(nullptr);
+    this->rangep(rangep);
+    dtypep(nullptr);  // V3Width will resolve
+    const int width = subDTypep()->width() * rangep->elementsConst();
+    widthForce(width, width);
+}
+AstPackArrayDType::AstPackArrayDType(FileLine* fl, AstNodeDType* dtp, AstRange* rangep)
+    : ASTGEN_SUPER_PackArrayDType(fl) {
+    refDTypep(dtp);
+    this->rangep(rangep);
+    dtypep(this);
+    const int width = subDTypep()->width() * rangep->elementsConst();
+    widthForce(width, width);
+}
+
+int AstBasicDType::hi() const { return (rangep() ? rangep()->hiConst() : m.m_nrange.hi()); }
+int AstBasicDType::lo() const { return (rangep() ? rangep()->loConst() : m.m_nrange.lo()); }
+int AstBasicDType::elements() const {
+    return (rangep() ? rangep()->elementsConst() : m.m_nrange.elements());
+}
+bool AstBasicDType::littleEndian() const {
+    return (rangep() ? rangep()->littleEndian() : m.m_nrange.littleEndian());
+}
+
+bool AstActive::hasInitial() const { return m_sensesp->hasInitial(); }
+bool AstActive::hasSettle() const { return m_sensesp->hasSettle(); }
+bool AstActive::hasClocked() const { return m_sensesp->hasClocked(); }
+
+AstElabDisplay::AstElabDisplay(FileLine* fl, VDisplayType dispType, AstNode* exprsp)
+    : ASTGEN_SUPER_ElabDisplay(fl) {
+    addFmtp(new AstSFormatF{fl, AstSFormatF::NoFormat(), exprsp});
+    m_displayType = dispType;
+}
+
+AstCStmt::AstCStmt(FileLine* fl, const string& textStmt)
+    : ASTGEN_SUPER_CStmt(fl) {
+    addExprsp(new AstText{fl, textStmt, true});
+}
+
+AstCMath::AstCMath(FileLine* fl, const string& textStmt, int setwidth, bool cleanOut)
+    : ASTGEN_SUPER_CMath(fl)
+    , m_cleanOut{cleanOut}
+    , m_pure{true} {
+    addExprsp(new AstText{fl, textStmt, true});
+    if (setwidth) dtypeSetLogicSized(setwidth, VSigning::UNSIGNED);
+}
+
+AstVarRef::AstVarRef(FileLine* fl, AstVar* varp, const VAccess& access)
+    : ASTGEN_SUPER_VarRef(fl, varp->name(), varp, access) {}
+// This form only allowed post-link (see above)
+AstVarRef::AstVarRef(FileLine* fl, AstVarScope* varscp, const VAccess& access)
+    : ASTGEN_SUPER_VarRef(fl, varscp->varp()->name(), varscp->varp(), access) {
+    varScopep(varscp);
+}
+bool AstVarRef::same(const AstVarRef* samep) const {
+    if (varScopep()) {
+        return (varScopep() == samep->varScopep() && access() == samep->access());
+    } else {
+        return (selfPointer() == samep->selfPointer() && varp()->name() == samep->varp()->name()
+                && access() == samep->access());
+    }
+}
+bool AstVarRef::sameNoLvalue(AstVarRef* samep) const {
+    if (varScopep()) {
+        return (varScopep() == samep->varScopep());
+    } else {
+        return (selfPointer() == samep->selfPointer()
+                && (!selfPointer().empty() || !samep->selfPointer().empty())
+                && varp()->name() == samep->varp()->name());
+    }
+}
+
+AstVarXRef::AstVarXRef(FileLine* fl, AstVar* varp, const string& dotted, const VAccess& access)
+    : ASTGEN_SUPER_VarXRef(fl, varp->name(), varp, access)
+    , m_dotted{dotted} {
    dtypeFrom(varp);
 }

-inline bool AstNodeDType::isFourstate() const { return basicp()->isFourstate(); }
-
-inline void AstNodeArrayDType::rangep(AstRange* nodep) { setOp2p(nodep); }
-inline int AstNodeArrayDType::left() const { return rangep()->leftConst(); }
-inline int AstNodeArrayDType::right() const { return rangep()->rightConst(); }
-inline int AstNodeArrayDType::hi() const { return rangep()->hiConst(); }
-inline int AstNodeArrayDType::lo() const { return rangep()->loConst(); }
-inline int AstNodeArrayDType::elementsConst() const { return rangep()->elementsConst(); }
-inline VNumRange AstNodeArrayDType::declRange() const { return VNumRange{left(), right()}; }
-
-inline void AstIfaceRefDType::cloneRelink() {
-    if (m_cellp && m_cellp->clonep()) m_cellp = m_cellp->clonep();
-    if (m_ifacep && m_ifacep->clonep()) m_ifacep = m_ifacep->clonep();
-    if (m_modportp && m_modportp->clonep()) m_modportp = m_modportp->clonep();
-}
-
 #endif  // Guard
@@ -26,7 +26,7 @@
 #include "V3PartitionGraph.h"  // Just for mtask dumping
 #include "V3String.h"

-#include "V3AstNodes__gen_macros.h"  // Generated by 'astgen'
+#include "V3Ast__gen_macros.h"  // Generated by 'astgen'

 #include <iomanip>
 #include <iterator>
@@ -155,6 +155,51 @@ void AstNodeCond::numberOperate(V3Number& out, const V3Number& lhs, const V3Numb
    }
 }

+void AstBasicDType::init(VBasicDTypeKwd kwd, VSigning numer, int wantwidth, int wantwidthmin,
+                         AstRange* rangep) {
+    // wantwidth=0 means figure it out, but if a widthmin is >=0
+    //    we allow width 0 so that {{0{x}},y} works properly
+    // wantwidthmin=-1:  default, use wantwidth if it is non zero
+    m.m_keyword = kwd;
+    // Implicitness: // "parameter X" is implicit and sized from initial
+    // value, "parameter reg x" not
+    if (keyword() == VBasicDTypeKwd::LOGIC_IMPLICIT) {
+        if (rangep || wantwidth) m.m_keyword = VBasicDTypeKwd::LOGIC;
+    }
+    if (numer == VSigning::NOSIGN) {
+        if (keyword().isSigned()) {
+            numer = VSigning::SIGNED;
+        } else if (keyword().isUnsigned()) {
+            numer = VSigning::UNSIGNED;
+        }
+    }
+    numeric(numer);
+    if (!rangep && (wantwidth || wantwidthmin >= 0)) {  // Constant width
+        if (wantwidth > 1) m.m_nrange.init(wantwidth - 1, 0, false);
+        const int wmin = wantwidthmin >= 0 ? wantwidthmin : wantwidth;
+        widthForce(wantwidth, wmin);
+    } else if (!rangep) {  // Set based on keyword properties
+        // V3Width will pull from this width
+        if (keyword().width() > 1 && !isOpaque()) {
+            m.m_nrange.init(keyword().width() - 1, 0, false);
+        }
+        widthForce(keyword().width(), keyword().width());
+    } else {
+        widthForce(rangep->elementsConst(),
+                   rangep->elementsConst());  // Maybe unknown if parameters underneath it
+    }
+    this->rangep(rangep);
+    this->dtypep(this);
+}
+
+void AstBasicDType::cvtRangeConst() {
+    if (rangep() && VN_IS(rangep()->leftp(), Const) && VN_IS(rangep()->rightp(), Const)) {
+        m.m_nrange = VNumRange{rangep()->leftConst(), rangep()->rightConst()};
+        rangep()->unlinkFrBackWithNext()->deleteTree();
+        rangep(nullptr);
+    }
+}
+
 int AstBasicDType::widthAlignBytes() const {
    if (width() <= 8) {
        return 1;
@@ -225,9 +270,10 @@ AstNodeBiop* AstEqWild::newTyped(FileLine* fl, AstNode* lhsp, AstNode* rhsp) {
    }
 }

-AstExecGraph::AstExecGraph(FileLine* fileline)
+AstExecGraph::AstExecGraph(FileLine* fileline, const string& name)
    : ASTGEN_SUPER_ExecGraph(fileline)
-    , m_depGraphp{new V3Graph} {}
+    , m_depGraphp{new V3Graph}
+    , m_name{name} {}

 AstExecGraph::~AstExecGraph() { VL_DO_DANGLING(delete m_depGraphp, m_depGraphp); }

@@ -454,25 +500,33 @@ string AstVar::cPubArgType(bool named, bool forReturn) const {
    if (forReturn) named = false;
    string arg;
    if (isWide() && isReadOnly()) arg += "const ";
-    if (widthMin() == 1) {
-        arg += "bool";
-    } else if (widthMin() <= VL_IDATASIZE) {
-        arg += "uint32_t";
-    } else if (widthMin() <= VL_QUADSIZE) {
-        arg += "vluint64_t";
-    } else {
-        arg += "uint32_t";  // []'s added later
-    }
-    if (isWide()) {
-        if (forReturn) {
-            v3warn(E_UNSUPPORTED, "Unsupported: Public functions with >64 bit outputs; "
-                                  "make an output of a public task instead");
+    const bool isRef = !forReturn && (isWritable() || direction().isRefOrConstRef());
+    if (VN_IS(dtypeSkipRefp(), BasicDType) && !dtypeSkipRefp()->isDouble()
+        && !dtypeSkipRefp()->isString()) {
+        // Backward compatible type declaration
+        if (widthMin() == 1) {
+            arg += "bool";
+        } else if (widthMin() <= VL_IDATASIZE) {
+            arg += "uint32_t";
+        } else if (widthMin() <= VL_QUADSIZE) {
+            arg += "uint64_t";
+        } else {
+            arg += "uint32_t";  // []'s added later
+        }
+        if (isWide()) {
+            if (forReturn) {
+                v3warn(E_UNSUPPORTED, "Unsupported: Public functions with >64 bit outputs; "
+                                      "make an output of a public task instead");
+            }
+            arg += " (& " + name();
+            arg += ")[" + cvtToStr(widthWords()) + "]";
+        } else {
+            if (isRef) arg += "&";
+            if (named) arg += " " + name();
        }
-        arg += " (& " + name();
-        arg += ")[" + cvtToStr(widthWords()) + "]";
    } else {
-        if (!forReturn && (isWritable() || direction().isRefOrConstRef())) arg += "&";
-        if (named) arg += " " + name();
+        // Newer internal-compatible types
+        arg += dtypep()->cType((named ? name() : std::string{}), true, isRef);
    }
    return arg;
 }
@@ -480,7 +534,7 @@ string AstVar::cPubArgType(bool named, bool forReturn) const {
 class dpiTypesToStringConverter VL_NOT_FINAL {
 public:
    virtual string openArray(const AstVar*) const { return "const svOpenArrayHandle"; }
-    virtual string bitLogicVector(const AstVar* varp, bool isBit) const {
+    virtual string bitLogicVector(const AstVar* /*varp*/, bool isBit) const {
        return isBit ? "svBitVecVal" : "svLogicVecVal";
    }
    virtual string primitive(const AstVar* varp) const {
@@ -510,11 +564,11 @@ string AstVar::dpiArgType(bool named, bool forReturn) const {
        return dpiTypesToStringConverter{}.convert(this);
    } else {
        class converter final : public dpiTypesToStringConverter {
-            virtual string bitLogicVector(const AstVar* varp, bool isBit) const override {
+            string bitLogicVector(const AstVar* varp, bool isBit) const override {
                return string(varp->isReadOnly() ? "const " : "")
                       + dpiTypesToStringConverter::bitLogicVector(varp, isBit) + '*';
            }
-            virtual string primitive(const AstVar* varp) const override {
+            string primitive(const AstVar* varp) const override {
                string type = dpiTypesToStringConverter::primitive(varp);
                if (varp->isWritable() || VN_IS(varp->dtypep()->skipRefp(), UnpackArrayDType)) {
                    if (!varp->isWritable() && varp->basicp()->keyword() != VBasicDTypeKwd::STRING)
@@ -546,16 +600,16 @@ string AstVar::dpiTmpVarType(const string& varName) const {
                return "";
            }
        }
-        virtual string openArray(const AstVar* varp) const override {
+        string openArray(const AstVar* varp) const override {
            return dpiTypesToStringConverter::openArray(varp) + ' ' + m_name
                   + arraySuffix(varp, 0);
        }
-        virtual string bitLogicVector(const AstVar* varp, bool isBit) const override {
+        string bitLogicVector(const AstVar* varp, bool isBit) const override {
            string type = dpiTypesToStringConverter::bitLogicVector(varp, isBit);
            type += ' ' + m_name + arraySuffix(varp, varp->widthWords());
            return type;
        }
-        virtual string primitive(const AstVar* varp) const override {
+        string primitive(const AstVar* varp) const override {
            string type = dpiTypesToStringConverter::primitive(varp);
            if (varp->isWritable() || VN_IS(varp->dtypep()->skipRefp(), UnpackArrayDType)) {
                if (!varp->isWritable() && varp->basicp()->keyword() == VBasicDTypeKwd::CHANDLE)
@@ -592,7 +646,7 @@ string AstVar::scType() const {
            return "uint32_t";
        }
    } else {
-        return "vluint64_t";
+        return "uint64_t";
    }
 }

@@ -606,29 +660,21 @@ AstVar* AstVar::scVarRecurse(AstNode* nodep) {
        } else {
            return nullptr;
        }
-    } else if (VN_IS(nodep, VarRef)) {
-        if (VN_AS(nodep, VarRef)->varp()->isSc()) {
-            return VN_AS(nodep, VarRef)->varp();
+    } else if (AstVarRef* const vrefp = VN_CAST(nodep, VarRef)) {
+        if (vrefp->varp()->isSc()) {
+            return vrefp->varp();
        } else {
            return nullptr;
        }
-    } else if (VN_IS(nodep, ArraySel)) {
-        if (nodep->op1p()) {
-            if (AstVar* p = scVarRecurse(nodep->op1p())) return p;
-        }
-        if (nodep->op2p()) {
-            if (AstVar* p = scVarRecurse(nodep->op2p())) return p;
-        }
-        if (nodep->op3p()) {
-            if (AstVar* p = scVarRecurse(nodep->op3p())) return p;
-        }
-        if (nodep->op4p()) {
-            if (AstVar* p = scVarRecurse(nodep->op4p())) return p;
-        }
+    } else if (AstArraySel* const arraySelp = VN_CAST(nodep, ArraySel)) {
+        if (AstVar* const p = scVarRecurse(arraySelp->fromp())) return p;
+        if (AstVar* const p = scVarRecurse(arraySelp->bitp())) return p;
    }
    return nullptr;
 }

+bool AstNodeDType::isFourstate() const { return basicp()->isFourstate(); }
+
 class AstNodeDType::CTypeRecursed final {
 public:
    string m_type;  // The base type, e.g.: "Foo_t"s
@@ -650,7 +696,7 @@ public:
    }
 };

-string AstNodeDType::cType(const string& name, bool forFunc, bool isRef) const {
+string AstNodeDType::cType(const string& name, bool /*forFunc*/, bool isRef) const {
    const CTypeRecursed info = cTypeRecurse(false);
    return info.render(name, isRef);
 }
@@ -664,6 +710,9 @@ AstNodeDType::CTypeRecursed AstNodeDType::cTypeRecurse(bool compound) const {
        const CTypeRecursed key = adtypep->keyDTypep()->cTypeRecurse(true);
        const CTypeRecursed val = adtypep->subDTypep()->cTypeRecurse(true);
        info.m_type = "VlAssocArray<" + key.m_type + ", " + val.m_type + ">";
+    } else if (const auto* const adtypep = VN_CAST(dtypep, WildcardArrayDType)) {
+        const CTypeRecursed sub = adtypep->subDTypep()->cTypeRecurse(true);
+        info.m_type = "VlAssocArray<std::string, " + sub.m_type + ">";
    } else if (const auto* const adtypep = VN_CAST(dtypep, DynArrayDType)) {
        const CTypeRecursed sub = adtypep->subDTypep()->cTypeRecurse(true);
        info.m_type = "VlQueue<" + sub.m_type + ">";
@@ -1011,8 +1060,13 @@ AstConstPool::AstConstPool(FileLine* fl)
    : ASTGEN_SUPER_ConstPool(fl)
    , m_modp{new AstModule(fl, "@CONST-POOL@")}
    , m_scopep{new AstScope(fl, m_modp, "@CONST-POOL@", nullptr, nullptr)} {
-    addOp1p(m_modp);
-    m_modp->addStmtp(m_scopep);
+    this->modulep(m_modp);
+    m_modp->addStmtsp(m_scopep);
+}
+const char* AstConstPool::broken() const {
+    BROKEN_RTN(m_modp && !m_modp->brokeExists());
+    BROKEN_RTN(m_scopep && !m_scopep->brokeExists());
+    return nullptr;
 }

 AstVarScope* AstConstPool::createNewEntry(const string& name, AstNode* initp) {
@@ -1021,9 +1075,9 @@ AstVarScope* AstConstPool::createNewEntry(const string& name, AstNode* initp) {
    varp->isConst(true);
    varp->isStatic(true);
    varp->valuep(initp->cloneTree(false));
-    m_modp->addStmtp(varp);
+    m_modp->addStmtsp(varp);
    AstVarScope* const varScopep = new AstVarScope(fl, m_scopep, varp);
-    m_scopep->addVarp(varScopep);
+    m_scopep->addVarsp(varScopep);
    return varScopep;
 }

@@ -1063,8 +1117,8 @@ static bool sameInit(const AstInitArray* ap, const AstInitArray* bp) {
        if (!aDTypep->rangep()->sameTree(bDTypep->rangep())) return false;
        // Compare initializer arrays by value. Note this is only called when they hash the same,
        // so they likely run at most once per call to 'AstConstPool::findTable'.
-        const vluint64_t size = aDTypep->elementsConst();
-        for (vluint64_t n = 0; n < size; ++n) {
+        const uint64_t size = aDTypep->elementsConst();
+        for (uint64_t n = 0; n < size; ++n) {
            const AstNode* const valAp = ap->getIndexDefaultedValuep(n);
            const AstNode* const valBp = bp->getIndexDefaultedValuep(n);
            if (!valAp->sameTree(valBp)) return false;
@@ -1169,7 +1223,7 @@ void AstWhile::addBeforeStmt(AstNode* newp, AstNode* belowp) {
    } else if (belowp == condp()) {
        // Goes before condition, IE in preconditions
        addPrecondsp(newp);
-    } else if (belowp == bodysp()) {
+    } else if (belowp == stmtsp()) {
        // Was first statement in body, so new front
        belowp->addHereThisAsNext(newp);
    } else {
@@ -1186,12 +1240,12 @@ void AstWhile::addNextStmt(AstNode* newp, AstNode* belowp) {
        belowp->addNextHere(newp);
    } else if (belowp == condp()) {
        // Becomes first statement in body, body may have been empty
-        if (bodysp()) {
-            bodysp()->addHereThisAsNext(newp);
+        if (stmtsp()) {
+            stmtsp()->addHereThisAsNext(newp);
        } else {
-            addBodysp(newp);
+            addStmtsp(newp);
        }
-    } else if (belowp == bodysp()) {
+    } else if (belowp == stmtsp()) {
        // Next statement in body
        belowp->addNextHere(newp);
    } else {
@@ -1212,10 +1266,10 @@ static std::string nodeAddr(const AstNode* nodep) {
 }

 void AstNode::dump(std::ostream& str) const {
-    str << typeName() << " "
-        << nodeAddr(this)
-        //<< " " << nodeAddr(m_backp)
+    str << typeName() << " " << nodeAddr(this)
+#ifdef VL_DEBUG
        << " <e" << std::dec << editCount() << ((editCount() >= editCountLast()) ? "#>" : ">")
+#endif
        << " {" << fileline()->filenameLetters() << std::dec << fileline()->lastLineno()
        << fileline()->firstColumnLetters() << "}";
    if (user1p()) str << " u1=" << nodeAddr(user1p());
@@ -1285,11 +1339,19 @@ void AstCell::dump(std::ostream& str) const {
        str << " ->UNLINKED:" << modName();
    }
 }
+const char* AstCell::broken() const {
+    BROKEN_RTN(m_modp && !m_modp->brokeExists());
+    return nullptr;
+}
 void AstCellInline::dump(std::ostream& str) const {
    this->AstNode::dump(str);
    str << " -> " << origModName();
    str << " [scopep=" << reinterpret_cast<const void*>(scopep()) << "]";
 }
+const char* AstCellInline::broken() const {
+    BROKEN_RTN(m_scopep && !m_scopep->brokeExists());
+    return nullptr;
+}
 const char* AstClassPackage::broken() const {
    BROKEN_BASE_RTN(AstNodeModule::broken());
    BROKEN_RTN(m_classp && !m_classp->brokeExists());
@@ -1300,7 +1362,8 @@ void AstClassPackage::cloneRelink() {
 }
 void AstClass::insertCache(AstNode* nodep) {
    const bool doit = (VN_IS(nodep, Var) || VN_IS(nodep, EnumItemRef)
-                       || (VN_IS(nodep, NodeFTask) && !VN_AS(nodep, NodeFTask)->isExternProto()));
+                       || (VN_IS(nodep, NodeFTask) && !VN_AS(nodep, NodeFTask)->isExternProto())
+                       || VN_IS(nodep, CFunc));
    if (doit) {
        if (m_members.find(nodep->name()) != m_members.end()) {
            nodep->v3error("Duplicate declaration of member name: " << nodep->prettyNameQ());
@@ -1311,7 +1374,15 @@ void AstClass::insertCache(AstNode* nodep) {
 }
 void AstClass::repairCache() {
    clearCache();
-    for (AstNode* itemp = membersp(); itemp; itemp = itemp->nextp()) { insertCache(itemp); }
+    for (auto* itemp = membersp(); itemp; itemp = itemp->nextp()) {
+        if (const auto* const scopep = VN_CAST(itemp, Scope)) {
+            for (auto* blockp = scopep->blocksp(); blockp; blockp = blockp->nextp()) {
+                insertCache(blockp);
+            }
+        } else {
+            insertCache(itemp);
+        }
+    }
 }
 bool AstClass::isClassExtendedFrom(const AstClass* refClassp, const AstClass* baseClassp) {
    // TAIL RECURSIVE
@@ -1325,6 +1396,17 @@ void AstClass::dump(std::ostream& str) const {
    if (isExtended()) str << " [EXT]";
    if (isVirtual()) str << " [VIRT]";
 }
+const char* AstClass::broken() const {
+    BROKEN_BASE_RTN(AstNodeModule::broken());
+    BROKEN_RTN(m_classOrPackagep && !m_classOrPackagep->brokeExists());
+    return nullptr;
+}
+void AstClass::cloneRelink() {
+    AstNodeModule::cloneRelink();
+    if (m_classOrPackagep && m_classOrPackagep->clonep()) {
+        m_classOrPackagep = m_classOrPackagep->clonep();
+    }
+}
 AstClass* AstClassExtends::classp() const {
    const AstClassRefDType* refp = VN_CAST(dtypep(), ClassRefDType);
    if (VL_UNLIKELY(!refp)) {  // LinkDot uses this for 'super.'
@@ -1334,7 +1416,7 @@ AstClass* AstClassExtends::classp() const {
    return refp->classp();
 }
 void AstClassRefDType::dump(std::ostream& str) const {
-    this->AstNode::dump(str);
+    this->AstNodeDType::dump(str);
    if (classOrPackagep()) str << " cpkg=" << nodeAddr(classOrPackagep());
    if (classp()) {
        str << " -> ";
@@ -1347,6 +1429,18 @@ void AstClassRefDType::dumpSmall(std::ostream& str) const {
    this->AstNodeDType::dumpSmall(str);
    str << "class:" << name();
 }
+const char* AstClassRefDType::broken() const {
+    BROKEN_RTN(m_classp && !m_classp->brokeExists());
+    BROKEN_RTN(m_classOrPackagep && !m_classOrPackagep->brokeExists());
+    return nullptr;
+}
+void AstClassRefDType::cloneRelink() {
+    if (m_classp && m_classp->clonep()) m_classp = m_classp->clonep();
+    if (m_classOrPackagep && m_classOrPackagep->clonep()) {
+        m_classOrPackagep = m_classOrPackagep->clonep();
+    }
+}
+string AstClassRefDType::name() const { return classp() ? classp()->name() : "<unlinked>"; }
 void AstNodeCoverOrAssert::dump(std::ostream& str) const {
    this->AstNodeStmt::dump(str);
    if (immediate()) str << " [IMMEDIATE]";
@@ -1364,8 +1458,13 @@ void AstEnumItemRef::dump(std::ostream& str) const {
        str << "UNLINKED";
    }
 }
+const char* AstEnumItemRef::broken() const {
+    BROKEN_RTN(m_itemp && !m_itemp->brokeExists());
+    BROKEN_RTN(m_classOrPackagep && !m_classOrPackagep->brokeExists());
+    return nullptr;
+}
 void AstIfaceRefDType::dump(std::ostream& str) const {
-    this->AstNode::dump(str);
+    this->AstNodeDType::dump(str);
    if (cellName() != "") str << " cell=" << cellName();
    if (ifaceName() != "") str << " if=" << ifaceName();
    if (modportName() != "") str << " mp=" << modportName();
@@ -1383,6 +1482,11 @@ void AstIfaceRefDType::dumpSmall(std::ostream& str) const {
    this->AstNodeDType::dumpSmall(str);
    str << "iface";
 }
+void AstIfaceRefDType::cloneRelink() {
+    if (m_cellp && m_cellp->clonep()) m_cellp = m_cellp->clonep();
+    if (m_ifacep && m_ifacep->clonep()) m_ifacep = m_ifacep->clonep();
+    if (m_modportp && m_modportp->clonep()) m_modportp = m_modportp->clonep();
+}
 void AstInitArray::dump(std::ostream& str) const {
    this->AstNode::dump(str);
    int n = 0;
@@ -1395,6 +1499,42 @@ void AstInitArray::dump(std::ostream& str) const {
        str << " [" << itr.first << "]=" << reinterpret_cast<const void*>(itr.second);
    }
 }
+const char* AstInitArray::broken() const {
+    for (KeyItemMap::const_iterator it = m_map.begin(); it != m_map.end(); ++it) {
+        BROKEN_RTN(!it->second);
+        BROKEN_RTN(!it->second->brokeExists());
+    }
+    return nullptr;
+}
+void AstInitArray::cloneRelink() {
+    for (KeyItemMap::iterator it = m_map.begin(); it != m_map.end(); ++it) {
+        if (it->second->clonep()) it->second = it->second->clonep();
+    }
+}
+void AstInitArray::addIndexValuep(uint64_t index, AstNode* newp) {
+    const auto it = m_map.find(index);
+    if (it != m_map.end()) {
+        it->second->valuep(newp);
+    } else {
+        AstInitItem* const itemp = new AstInitItem(fileline(), newp);
+        m_map.emplace(index, itemp);
+        addInitsp(itemp);
+    }
+}
+AstNode* AstInitArray::getIndexValuep(uint64_t index) const {
+    const auto it = m_map.find(index);
+    if (it == m_map.end()) {
+        return nullptr;
+    } else {
+        return it->second->valuep();
+    }
+}
+AstNode* AstInitArray::getIndexDefaultedValuep(uint64_t index) const {
+    AstNode* valuep = getIndexValuep(index);
+    if (!valuep) valuep = defaultp();
+    return valuep;
+}
+
 void AstJumpGo::dump(std::ostream& str) const {
    this->AstNodeStmt::dump(str);
    str << " -> ";
@@ -1404,6 +1544,13 @@ void AstJumpGo::dump(std::ostream& str) const {
        str << "%Error:UNLINKED";
    }
 }
+const char* AstJumpGo::broken() const {
+    BROKEN_RTN(!labelp()->brokeExistsBelow());
+    return nullptr;
+}
+void AstJumpGo::cloneRelink() {
+    if (m_labelp->clonep()) m_labelp = m_labelp->clonep();
+}
 void AstJumpLabel::dump(std::ostream& str) const {
    this->AstNodeStmt::dump(str);
    str << " -> ";
@@ -1414,7 +1561,7 @@ void AstJumpLabel::dump(std::ostream& str) const {
    }
 }
 void AstLogOr::dump(std::ostream& str) const {
-    this->AstNode::dump(str);
+    this->AstNodeMath::dump(str);
    if (sideEffect()) str << " [SIDE]";
 }
 void AstMemberSel::dump(std::ostream& str) const {
@@ -1426,8 +1573,15 @@ void AstMemberSel::dump(std::ostream& str) const {
        str << "%Error:UNLINKED";
    }
 }
+void AstMemberSel::cloneRelink() {
+    if (m_varp && m_varp->clonep()) m_varp = m_varp->clonep();
+}
+const char* AstMemberSel::broken() const {
+    BROKEN_RTN(m_varp && !m_varp->brokeExists());
+    return nullptr;
+}
 void AstMethodCall::dump(std::ostream& str) const {
-    this->AstNodeStmt::dump(str);
+    this->AstNodeFTaskRef::dump(str);
    if (isStatement()) str << " [STMT]";
    str << " -> ";
    if (taskp()) {
@@ -1447,6 +1601,13 @@ void AstModportFTaskRef::dump(std::ostream& str) const {
        str << " -> UNLINKED";
    }
 }
+const char* AstModportFTaskRef::broken() const {
+    BROKEN_RTN(m_ftaskp && !m_ftaskp->brokeExists());
+    return nullptr;
+}
+void AstModportFTaskRef::cloneRelink() {
+    if (m_ftaskp && m_ftaskp->clonep()) m_ftaskp = m_ftaskp->clonep();
+}
 void AstModportVarRef::dump(std::ostream& str) const {
    this->AstNode::dump(str);
    if (direction().isAny()) str << " " << direction();
@@ -1457,6 +1618,13 @@ void AstModportVarRef::dump(std::ostream& str) const {
        str << " -> UNLINKED";
    }
 }
+const char* AstModportVarRef::broken() const {
+    BROKEN_RTN(m_varp && !m_varp->brokeExists());
+    return nullptr;
+}
+void AstModportVarRef::cloneRelink() {
+    if (m_varp && m_varp->clonep()) m_varp = m_varp->clonep();
+}
 void AstPin::dump(std::ostream& str) const {
    this->AstNode::dump(str);
    if (modVarp()) {
@@ -1467,6 +1635,17 @@ void AstPin::dump(std::ostream& str) const {
    }
    if (svImplicit()) str << " [.SV]";
 }
+const char* AstPin::broken() const {
+    BROKEN_RTN(m_modVarp && !m_modVarp->brokeExists());
+    BROKEN_RTN(m_modPTypep && !m_modPTypep->brokeExists());
+    return nullptr;
+}
+string AstPin::prettyOperatorName() const {
+    return modVarp()
+               ? ((modVarp()->direction().isAny() ? modVarp()->direction().prettyName() + " " : "")
+                  + "port connection " + modVarp()->prettyNameQ())
+               : "port connection";
+}
 void AstPrintTimeScale::dump(std::ostream& str) const {
    this->AstNodeStmt::dump(str);
    str << " " << timeunit();
@@ -1512,8 +1691,25 @@ void AstRefDType::dump(std::ostream& str) const {
        str << " -> UNLINKED";
    }
 }
+const char* AstRefDType::broken() const {
+    BROKEN_RTN(m_typedefp && !m_typedefp->brokeExists());
+    BROKEN_RTN(m_refDTypep && !m_refDTypep->brokeExists());
+    BROKEN_RTN(m_classOrPackagep && !m_classOrPackagep->brokeExists());
+    return nullptr;
+}
+void AstRefDType::cloneRelink() {
+    if (m_typedefp && m_typedefp->clonep()) m_typedefp = m_typedefp->clonep();
+    if (m_refDTypep && m_refDTypep->clonep()) m_refDTypep = m_refDTypep->clonep();
+    if (m_classOrPackagep && m_classOrPackagep->clonep()) {
+        m_classOrPackagep = m_classOrPackagep->clonep();
+    }
+}
+AstNodeDType* AstRefDType::subDTypep() const {
+    if (typedefp()) return typedefp()->subDTypep();
+    return refDTypep();  // Maybe nullptr
+}
 void AstNodeUOrStructDType::dump(std::ostream& str) const {
-    this->AstNode::dump(str);
+    this->AstNodeDType::dump(str);
    if (packed()) str << " [PACKED]";
    if (isFourstate()) str << " [4STATE]";
 }
@@ -1582,6 +1778,32 @@ void AstNetlist::dump(std::ostream& str) const {
    this->AstNode::dump(str);
    str << " [" << timeunit() << "/" << timeprecision() << "]";
 }
+const char* AstNetlist::broken() const {
+    BROKEN_RTN(m_typeTablep && !m_typeTablep->brokeExists());
+    BROKEN_RTN(m_constPoolp && !m_constPoolp->brokeExists());
+    BROKEN_RTN(m_dollarUnitPkgp && !m_dollarUnitPkgp->brokeExists());
+    BROKEN_RTN(m_evalp && !m_evalp->brokeExists());
+    BROKEN_RTN(m_dpiExportTriggerp && !m_dpiExportTriggerp->brokeExists());
+    BROKEN_RTN(m_topScopep && !m_topScopep->brokeExists());
+    return nullptr;
+}
+AstPackage* AstNetlist::dollarUnitPkgAddp() {
+    if (!m_dollarUnitPkgp) {
+        m_dollarUnitPkgp = new AstPackage(fileline(), AstPackage::dollarUnitName());
+        // packages are always libraries; don't want to make them a "top"
+        m_dollarUnitPkgp->inLibrary(true);
+        m_dollarUnitPkgp->modTrace(false);  // may reconsider later
+        m_dollarUnitPkgp->internal(true);
+        addModulesp(m_dollarUnitPkgp);
+    }
+    return m_dollarUnitPkgp;
+}
+void AstNetlist::createTopScope(AstScope* scopep) {
+    UASSERT(scopep, "Must not be nullptr");
+    UASSERT_OBJ(!m_topScopep, scopep, "TopScope already exits");
+    m_topScopep = new AstTopScope{scopep->modp()->fileline(), scopep};
+    scopep->modp()->addStmtsp(v3Global.rootp()->topScopep());
+}
 void AstNodeModule::dump(std::ostream& str) const {
    this->AstNode::dump(str);
    str << "  L" << level();
@@ -1599,12 +1821,26 @@ void AstPackageExport::dump(std::ostream& str) const {
    this->AstNode::dump(str);
    str << " -> " << packagep();
 }
+const char* AstPackageExport ::broken() const {
+    BROKEN_RTN(!m_packagep || !m_packagep->brokeExists());
+    return nullptr;
+}
+void AstPackageExport::cloneRelink() {
+    if (m_packagep && m_packagep->clonep()) m_packagep = m_packagep->clonep();
+}
 void AstPackageImport::dump(std::ostream& str) const {
    this->AstNode::dump(str);
    str << " -> " << packagep();
 }
+const char* AstPackageImport::broken() const {
+    BROKEN_RTN(!m_packagep || !m_packagep->brokeExists());
+    return nullptr;
+}
+void AstPackageImport::cloneRelink() {
+    if (m_packagep && m_packagep->clonep()) m_packagep = m_packagep->clonep();
+}
 void AstPatMember::dump(std::ostream& str) const {
-    this->AstNode::dump(str);
+    this->AstNodeMath::dump(str);
    if (isDefault()) str << " [DEFAULT]";
 }
 void AstNodeTriop::dump(std::ostream& str) const { this->AstNodeMath::dump(str); }
@@ -1629,7 +1865,7 @@ void AstTypeTable::dump(std::ostream& str) const {
    for (int i = 0; i < static_cast<int>(VBasicDTypeKwd::_ENUM_MAX); ++i) {
        if (AstBasicDType* const subnodep = m_basicps[i]) {
            str << '\n';  // Newline from caller, so newline first
-            str << "\t\t" << std::setw(8) << VBasicDTypeKwd(i).ascii();
+            str << "\t\t" << std::setw(8) << VBasicDTypeKwd{i}.ascii();
            str << "  -> ";
            subnodep->dump(str);
        }
@@ -1666,10 +1902,34 @@ string AstQueueDType::prettyDTypeName() const {
    if (boundConst()) str += ":" + cvtToStr(boundConst());
    return str + "]";
 }
+void AstWildcardArrayDType::dumpSmall(std::ostream& str) const {
+    this->AstNodeDType::dumpSmall(str);
+    str << "[*]";
+}
+bool AstWildcardArrayDType::same(const AstNode* samep) const {
+    const AstNodeArrayDType* const asamep = static_cast<const AstNodeArrayDType*>(samep);
+    if (!asamep->subDTypep()) return false;
+    return (subDTypep() == asamep->subDTypep());
+}
+bool AstWildcardArrayDType::similarDType(AstNodeDType* samep) const {
+    const AstNodeArrayDType* const asamep = static_cast<const AstNodeArrayDType*>(samep);
+    return type() == samep->type() && asamep->subDTypep()
+           && subDTypep()->skipRefp()->similarDType(asamep->subDTypep()->skipRefp());
+}
 void AstUnsizedArrayDType::dumpSmall(std::ostream& str) const {
    this->AstNodeDType::dumpSmall(str);
    str << "[]";
 }
+bool AstUnsizedArrayDType::same(const AstNode* samep) const {
+    const AstNodeArrayDType* const asamep = static_cast<const AstNodeArrayDType*>(samep);
+    if (!asamep->subDTypep()) return false;
+    return (subDTypep() == asamep->subDTypep());
+}
+bool AstUnsizedArrayDType::similarDType(AstNodeDType* samep) const {
+    const AstNodeArrayDType* const asamep = static_cast<const AstNodeArrayDType*>(samep);
+    return type() == samep->type() && asamep->subDTypep()
+           && subDTypep()->skipRefp()->similarDType(asamep->subDTypep()->skipRefp());
+}
 void AstEmptyQueueDType::dumpSmall(std::ostream& str) const {
    this->AstNodeDType::dumpSmall(str);
    str << "emptyq";
@@ -1717,6 +1977,9 @@ void AstVarRef::dump(std::ostream& str) const {
        str << "UNLINKED";
    }
 }
+bool AstVarRef::same(const AstNode* samep) const {
+    return same(static_cast<const AstVarRef*>(samep));
+}
 void AstVar::dump(std::ostream& str) const {
    this->AstNode::dump(str);
    if (isSc()) str << " [SC]";
@@ -1749,7 +2012,7 @@ void AstScope::dump(std::ostream& str) const {
    str << " [modp=" << reinterpret_cast<const void*>(modp()) << "]";
 }
 void AstScopeName::dump(std::ostream& str) const {
-    this->AstNode::dump(str);
+    this->AstNodeMath::dump(str);
    if (dpiExport()) str << " [DPIEX]";
    if (forFormat()) str << " [FMT]";
 }
@@ -1761,6 +2024,10 @@ void AstSenItem::dump(std::ostream& str) const {
    this->AstNode::dump(str);
    str << " [" << edgeType().ascii() << "]";
 }
+void AstStrengthSpec::dump(std::ostream& str) const {
+    this->AstNode::dump(str);
+    str << " (" << m_s0.ascii() << ", " << m_s1.ascii() << ")";
+}
 void AstParseRef::dump(std::ostream& str) const {
    this->AstNode::dump(str);
    str << " [" << expect().ascii() << "]";
@@ -1775,6 +2042,13 @@ void AstClassOrPackageRef::dump(std::ostream& str) const {
        str << "UNLINKED";
    }
 }
+AstNodeModule* AstClassOrPackageRef::classOrPackagep() const {
+    AstNode* foundp = m_classOrPackageNodep;
+    while (auto* const anodep = VN_CAST(foundp, Typedef)) foundp = anodep->subDTypep();
+    if (auto* const anodep = VN_CAST(foundp, ClassRefDType)) foundp = anodep->classp();
+    return VN_CAST(foundp, NodeModule);
+}
+
 void AstDot::dump(std::ostream& str) const {
    this->AstNode::dump(str);
    if (colon()) str << " [::]";
@@ -1788,6 +2062,16 @@ void AstActive::dump(std::ostream& str) const {
        str << "UNLINKED";
    }
 }
+const char* AstActive::broken() const {
+    BROKEN_RTN(m_sensesp && !m_sensesp->brokeExists());
+    return nullptr;
+}
+void AstActive::cloneRelink() {
+    if (m_sensesp->clonep()) {
+        m_sensesp = m_sensesp->clonep();
+        UASSERT(m_sensesp, "Bad clone cross link: " << this);
+    }
+}
 void AstNodeFTaskRef::dump(std::ostream& str) const {
    this->AstNodeStmt::dump(str);
    if (classOrPackagep()) str << " pkg=" << nodeAddr(classOrPackagep());
@@ -1816,7 +2100,7 @@ void AstNodeBlock::dump(std::ostream& str) const {
    if (unnamed()) str << " [UNNAMED]";
 }
 void AstBegin::dump(std::ostream& str) const {
-    this->AstNode::dump(str);
+    this->AstNodeBlock::dump(str);
    if (generate()) str << " [GEN]";
    if (genforp()) str << " [GENFOR]";
    if (implied()) str << " [IMPLIED]";
@@ -1842,9 +2126,13 @@ void AstCoverInc::dump(std::ostream& str) const {
    }
 }
 void AstFork::dump(std::ostream& str) const {
-    this->AstNode::dump(str);
+    this->AstNodeBlock::dump(str);
    if (!joinType().join()) str << " [" << joinType() << "]";
 }
+void AstTraceDecl::dump(std::ostream& str) const {
+    this->AstNodeStmt::dump(str);
+    if (code()) str << " [code=" << code() << "]";
+}
 void AstTraceInc::dump(std::ostream& str) const {
    this->AstNodeStmt::dump(str);
    str << " -> ";
@@ -1887,6 +2175,14 @@ void AstCFunc::dump(std::ostream& str) const {
    if (isDestructor()) str << " [DTOR]";
    if (isVirtual()) str << " [VIRT]";
 }
+const char* AstCFunc::broken() const {
+    BROKEN_RTN((m_scopep && !m_scopep->brokeExists()));
+    return nullptr;
+}
+void AstCFunc::cloneRelink() {
+    if (m_scopep && m_scopep->clonep()) m_scopep = m_scopep->clonep();
+}
+
 void AstCUse::dump(std::ostream& str) const {
    this->AstNode::dump(str);
    str << " [" << useType() << "]";
--- a/Show More
+++ b/Show More