Merge from master for release. (update)

Update CMakeList version
Merge from master for release.
2026-10-02 16:13:34 +02:00 · 2023-09-16 21:44:39 -04:00 · 2023-09-16 20:54:54 -04:00 · 2023-09-16 20:43:53 -04:00 · 2023-09-16 18:36:39 -04:00 · 2023-09-16 17:52:02 -04:00
986 changed files with 102657 additions and 9805 deletions
@@ -36,12 +36,14 @@ jobs:
        m32: [0, 1]
        exclude:
          # Build pull requests only with ubuntu-22.04 and without m32
-          - os:  ${{ github.event_name == 'pull_request' && 'ubuntu-18.04' || 'do-not-exclude' }}
-          - os:  ${{ github.event_name == 'pull_request' && 'ubuntu-20.04' || 'do-not-exclude' }}
-          - m32: ${{ github.event_name == 'pull_request' && 1              || 'do-not-exclude' }}
-          # Build -m32 only on ubuntu-22.04
+          # - os:  ${{ github.event_name == 'pull_request' && 'ubuntu-18.04' || 'do-not-exclude' }}
+          # - os:  ${{ github.event_name == 'pull_request' && 'ubuntu-20.04' || 'do-not-exclude' }}
+          # - m32: ${{ github.event_name == 'pull_request' && 1              || 'do-not-exclude' }}
+          # Build -m32 only on ubuntu-22.04 clang++
          - {os: ubuntu-18.04, m32: 1}
          - {os: ubuntu-20.04, m32: 1}
+          - compiler: { cc: gcc, cxx: g++ }
+            m32: 1
        include:
          # Build GCC 10 on ubuntu-20.04
          - os: ubuntu-20.04
@@ -105,12 +107,14 @@ jobs:
        suite: [dist-vlt-0, dist-vlt-1, dist-vlt-2, vltmt-0, vltmt-1]
        exclude:
          # Build pull requests only with ubuntu-22.04 and without m32
-          - os:  ${{ github.event_name == 'pull_request' && 'ubuntu-18.04' || 'do-not-exclude' }}
-          - os:  ${{ github.event_name == 'pull_request' && 'ubuntu-20.04' || 'do-not-exclude' }}
-          - m32: ${{ github.event_name == 'pull_request' && 1              || 'do-not-exclude' }}
+          # - os:  ${{ github.event_name == 'pull_request' && 'ubuntu-18.04' || 'do-not-exclude' }}
+          # - os:  ${{ github.event_name == 'pull_request' && 'ubuntu-20.04' || 'do-not-exclude' }}
+          # - m32: ${{ github.event_name == 'pull_request' && 1              || 'do-not-exclude' }}
          # Build -m32 only on ubuntu-22.04
          - {os: ubuntu-18.04, m32: 1}
          - {os: ubuntu-20.04, m32: 1}
+          - compiler: { cc: gcc, cxx: g++ }
+            m32: 1
        include:
          # Test with GCC 10 on ubuntu-20.04 without m32
          - {os: ubuntu-20.04, compiler: { cc: gcc-10, cxx: g++-10 }, m32: 0, suite: dist-vlt-0}
@@ -0,0 +1,85 @@
+# Build and push verilator docker image when tags are pushed to the repository.
+# The following variable(s) must be configured in the github repository:
+# DOCKER_HUB_NAMESPACE: docker hub namespace.
+# The following secrets must be configured in the github repository:
+# DOCKER_HUB_USER: user name for logging into docker hub
+# DOCKER_HUB_ACCESS_TOKEN: docker hub access token.
+name: Build Verilator Container
+
+on:
+  push:
+    tags: [ 'v*' ]
+  workflow_dispatch:
+    inputs:
+      manual_tag:
+        description: 'Git tag to use for image build'
+        required: true
+        type: string
+      add_latest_tag:
+        description: 'Tag workflow_dispatch docker image as "latest"'
+        required: true
+        type: boolean
+        default: false
+
+jobs:
+
+  build:
+
+    runs-on: ubuntu-22.04
+
+    strategy:
+      matrix:
+        contexts:
+          - "ci/docker/run:verilator"
+          # - "ci/docker/buildenv:verilator-buildenv"
+
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v3
+
+    - name: Extract context variables
+      run: |
+        echo "${{ matrix.contexts }}" | sed -r 's/(.*):.*/build_context=\1/' >> "$GITHUB_ENV"
+        echo "${{ matrix.contexts }}" | sed -r 's/.*:(.*)/image_name=\1/' >> "$GITHUB_ENV"
+        echo "git_tag=${GITHUB_REF#refs/*/}" >> "$GITHUB_ENV"
+
+    - name: Use manual tag
+      if: ${{ inputs.manual_tag }}
+      run: |
+        echo "git_tag=${{ inputs.manual_tag }}" >> "$GITHUB_ENV"
+
+    - name: Docker meta
+      id: docker_meta
+      uses: docker/metadata-action@v4
+      with:
+        images: |
+          ${{ vars.DOCKER_HUB_NAMESPACE }}/${{ env.image_name }}
+        tags: |
+          type=match,pattern=(v.*),group=1,enable=${{ startsWith(github.ref, 'refs/tags/v') }}
+          type=raw,value=${{ inputs.manual_tag }},enable=${{ inputs.manual_tag != '' }}
+          type=raw,value=latest,enable=${{ inputs.add_latest_tag == true }}
+
+    - name: Set up QEMU
+      uses: docker/setup-qemu-action@v2
+
+    - name: Set up Docker Buildx
+      uses: docker/setup-buildx-action@v2
+      with:
+          buildkitd-flags: --debug
+
+    - name: Login to Docker Hub
+      uses: docker/login-action@v2
+      with:
+        username: ${{ secrets.DOCKER_HUB_USER }}
+        password: ${{ secrets.DOCKER_HUB_ACCESS_TOKEN }}
+
+    - name: Build and Push to Docker
+      uses: docker/build-push-action@v4
+      if: startsWith(github.ref, 'refs/tags/v')
+      with:
+        context: ${{ env.build_context }}
+        build-args: SOURCE_COMMIT=${{ env.git_tag }}
+        platforms: linux/arm64,linux/amd64
+        push: ${{ !env.ACT && startsWith(github.ref, 'refs/tags/v') }}
+        tags: ${{ steps.docker_meta.outputs.tags }}
+        labels: ${{ steps.docker_meta.outputs.labels }}
@@ -41,3 +41,5 @@ verilator-config-version.cmake
 **/_build/*
 **/obj_dir/*
 /.vscode/
+/.idea/
+/cmake-build-*/
@@ -15,7 +15,7 @@
 cmake_minimum_required(VERSION 3.15)
 cmake_policy(SET CMP0091 NEW) # Use MSVC_RUNTIME_LIBRARY to select the runtime
 project(Verilator
-    VERSION 5.008
+    VERSION 5.016
    HOMEPAGE_URL https://verilator.org
    LANGUAGES CXX
 )
@@ -23,7 +23,8 @@ project(Verilator
 option(DEBUG_AND_RELEASE_AND_COVERAGE
    "Builds both the debug and release binaries, overriding CMAKE_BUILD_TYPE. Not supported under MSBuild.")

-set(PYTHON3 python)
+find_package(Python3 COMPONENTS Interpreter)
+set(PYTHON3 Python3::Interpreter)
 set(CMAKE_INSTALL_DATADIR ${CMAKE_INSTALL_PREFIX})
 include(GNUInstallDirs)
 include(CMakePackageConfigHelpers)
@@ -44,15 +45,7 @@ if (MSVC)
    if (NOT WIN_FLEX_BISON)
        message(FATAL_ERROR "Please install https://github.com/lexxmark/winflexbison and set WIN_FLEX_BISON environment variable. Please use install cmake target after a successful build.")
    endif()
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /std:c++20")
-else()
-    if (NOT DEFINED ENV{FLEX_INCLUDE})
-        message(FATAL_ERROR "Please set environment variable FLEX_INCLUDE to the directory containing FlexLexer.h")
-    endif()
-    set(WIN_FLEX_BISON "$ENV{FLEX_INCLUDE}")
-    if (WIN32 AND NOT MINGW)
-        set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++20")
-    endif()
+    set(CMAKE_CXX_STANDARD 20)
 endif()

 find_package(BISON)
@@ -99,6 +92,7 @@ configure_package_config_file(verilator-config-version.cmake.in verilator-config
 install(FILES ${CMAKE_CURRENT_BINARY_DIR}/verilator-config-version.cmake DESTINATION ${CMAKE_INSTALL_PREFIX})

 foreach (program
+    verilator
    verilator_gantt
    verilator_ccache_report
    verilator_difftree
@@ -8,6 +8,236 @@ The changes in each Verilator version are described below.  The
 contributors that suggested a given feature are shown in []. Thanks!


+Verilator 5.016 2023-09-16
+==========================
+
+**Minor:**
+
+* Add prepareClone and atClone APIs for Verilated models (#3503) (#4444). [Yinan Xu]
+* Add check for conflicting options e.g. binary and lint-only (#4409). [Ethan Sifferman]
+* Add --no-trace-top to not trace top signals (#4412) (#4422). [Frans Skarman]
+* Support recursive function calls (#3267).
+* Support assignments of packed values to stream expressions on queues (#4401). [Ryszard Rozak, Antmicro Ltd]
+* Support no-parentheses calls to static methods (#4432). [Krzysztof Boroński]
+* Support block_item_declaration in forks (#4455). [Krzysztof Boroński]
+* Support assignments of stream expressions on queues to packed values (#4458). [Ryszard Rozak, Antmicro Ltd]
+* Support function non-constant default arguments (#4470).
+* Support 'let'.
+* Optimize Verilator executable size by refactoring error reporting routines (#4446). [Anthony Donlon]
+* Optimize Verilation runtime pointers and graphs (#4396) (#4397) (#4398). [Krzysztof Bieganski, Antmicro Ltd]
+* Optimize preparations towards multithreaded Verilation (#4291) (#4463) (#4476) (#4477) (#4479).  [Kamil Rakoczy, Antmicro Ltd]
+* Fix Windows filename format, etc (#3873) (#4421). [Anthony Donlon].
+* Fix t_dist_cppstyle Perl performance issue (#4085). [Srinivasan Venkataramanan]
+* Fix using type in parameterized classes without #() (#4281) (#4440). [Anthony Donlon]
+* Fix false INFINITELOOP on forever..mailbox.get() (#4323). [Srinivasan Venkataramanan]
+* Fix data type of condition operation on class objects (#4345) (#4352). [Ryszard Rozak, Antmicro Ltd]
+* Fix variables mutated under fork..join_none/join_any blocks into anonymous objects (#4356). [Krzysztof Boroński]
+* Fix V3CUse, do not consider implementations (.cpp) at all (#4386). [Krzysztof Boroński]
+* Fix ++/-- under statements (#4399). [Aleksander Kiryk, Antmicro Ltd]
+* Fix detection of mixed blocking and nonblocking assignment in nested assignments (#4404). [Ryszard Rozak, Antmicro Ltd]
+* Fix jumping over object initialization (#4411). [Krzysztof Boroński]
+* Fix multiple issues towards short circuit support (#4413) (#4460). [Ryszard Rozak, Antmicro Ltd]
+* Fix variable lifetimes in extern methods (#4414). [Krzysztof Boroński]
+* Fix multiple function definitions in V3Sched (#4416). [Hennadii Chernyshchyk]
+* Fix false UNUSEDPARAM on generate localparam (#4427). [Bill Pringlemeir]
+* Fix checking for parameter and port connections in the wrong place (#4428). [Anthony Donlon]
+* Fix coroutine handle movement during queue manipulation (#4431). [Aleksander Kiryk, Antmicro Ltd]
+* Fix nested assignments on the LHS (#4435). [Ryszard Rozak, Antmicro Ltd]
+* Fix false MULTITOP on bound interfaces (#4438). [Alex Solomatnikov]
+* Fix internal error on real conversion (#4447). [vdhotre-ventana]
+* Fix lifetime unknown error on enum.name (#4448). [jwoutersymatra]
+* Fix unstable output of VHashSha256 (#4453). [Anthony Donlon]
+* Fix static cast from a stream type (#4469) (#4485). [Ryszard Rozak, Antmicro Ltd]
+* Fix error on enum with VARHIDDEN of cell (#4482). [Michail Rontionov]
+* Fix lint of case statements with enum and wildcard bits (#4464) (#4487). [Anthony Donlon]
+* Fix reference to extended class in parameterized class (#4466).
+* Fix recursive display causing segfault (#4480). [Kuoping Hsu]
+* Fix the error message when the type of ref argument is wrong (#4490). [Ryszard Rozak, Antmicro Ltd]
+* Fix display %x formatting of real.
+* Fix mis-warning on #() in classes' own functions.
+* Fix IGNOREDRETURN to not warn on void-cast static function calls.
+* Fix ZERODLY to not warn on 'wait(0)'.
+
+
+Verilator 5.014 2023-08-06
+==========================
+
+**Minor:**
+
+* Deprecation planned for 32-bit pointer -m32 mode (#4268).
+* Deprecate CMake config below version 3.13 (#4389) (#4390). [Vito Gamberini]
+* Support some stream operations on queues (#4292). [Ryszard Rozak, Antmicro Ltd]
+* Support property declaration with empty parentheses (#4313) (#4317). [Anthony Donlon]
+* Support locator methods with "with" on assoc arrays (#4335). [Ryszard Rozak, Antmicro Ltd]
+* Support string replication with variable (#4341). [Aleksander Kiryk, Antmicro Ltd]
+* Support more types in wait (#4374). [Aleksander Kiryk, Antmicro Ltd]
+* Support static method calls as default values of function arguments (#4378). [Ryszard Rozak, Antmicro Ltd]
+* Add GENUNNAMED lint warning. [Srinivasan Venkataramanan, Deepa Palaniappan]
+* Add MISINDENT lint warning for misleading indentation.
+* Fix 'VlForkSync' redeclaration (#4277). [Krzysztof Bieganski, Antmicro Ltd]
+* Fix processes that can outlive their parents (#4253). [Krzysztof Boronski, Antmicro Ltd]
+* Fix duplicate fork names (#4295). [Ryszard Rozak, Antmicro Ltd]
+* Fix splitting coroutines (#4297) (#4307). [Jiamin Zhu]
+* Fix error when multiple duplicate DPI exports (#4301).
+* Fix class reference assignment checking (#4296). [Ryszard Rozak, Antmicro Ltd]
+* Fix handling of ref types in initial values of type parameters (#4304). [Ryszard Rozak, Antmicro Ltd]
+* Fix comparison of string parameters (#4308). [Ryszard Rozak, Antmicro Ltd]
+* Fix state update for always processes (#4311). [Aleksander Kiryk, Antmicro Ltd]
+* Fix multiple edge timing controls in class methods (#4318) (#4320) (#4344). [Krzysztof Bieganski, Antmicro Ltd]
+* Fix implicit calls of base class constructors with optional arguments (#4319). [Ryszard Rozak, Antmicro Ltd]
+* Fix propagation of process requirement (#4321). [Krzysztof Boroński]
+* Fix unhandled overloads in V3InstrCount (#4324). [Krzysztof Boroński]
+* Fix selects of static members (#4326). [Ryszard Rozak, Antmicro Ltd]
+* Fix references to members of results of static methods (#4327). [Ryszard Rozak, Antmicro Ltd]
+* Fix unique..with method on queues of class objects (#4328). [Ryszard Rozak, Antmicro Ltd]
+* Fix queue slicing (#4329). [Aleksander Kiryk, Antmicro Ltd]
+* Fix wildcard referring types (#4336) (#4342). [Aleksander Kiryk, Antmicro Ltd]
+* Fix comparison of class objects (#4346). [Ryszard Rozak, Antmicro Ltd]
+* Fix unexpected RefDType on assoc arrays (#4337). [Aleksander Kiryk, Antmicro Ltd]
+* Fix cmake astgen for Rocky Linux 8.7 (#4343). [Julian Daube]
+* Fix class timescale in class packages (#4348). [Krzysztof Bieganski, Antmicro Ltd]
+* Fix string concatenations (#4354). [Ryszard Rozak, Antmicro Ltd]
+* Fix unlinked task error from broken context (#4355) (#4402). [Aleksander Kiryk, Antmicro Ltd]
+* Fix selects on unpacked structs (#4359). [Ryszard Rozak, Antmicro Ltd]
+* Fix select operation on assoc array with wide keys (#4360). [Ryszard Rozak, Antmicro Ltd]
+* Fix non-public methods with wide output (#4364). [Ryszard Rozak, Antmicro Ltd]
+* Fix handling of super.new calls (#4366). [Ryszard Rozak, Antmicro Ltd]
+* Fix assign to input var in methods (#4367). [Aleksander Kiryk, Antmicro Ltd]
+* Fix VlProcess not found (#4368). [Aleksander Kiryk, Antmicro Ltd]
+* Fix order of evaluation of function calls in statements (#4375). [Ryszard Rozak, Antmicro Ltd]
+* Fix config_build.h issues (#4380) (#4381). [Andrew Miloradovsky]
+
+
+Verilator 5.012 2023-06-13
+==========================
+
+**Major:**
+
+* With -j or --build-jobs, multithread Verilator's emit phase of Verilation. [Kamil Rakoczy, Antmicro Ltd]
+  Additional Verilator-internal stages will become multithreaded over time.
+
+**Minor:**
+
+* Add --main-top-name option for C main TOP name (#4235) (#4249). [Don Williamson]
+* Add creating __inputs.vpp file with --debug (#4177). [Tudor Timi]
+* Add NEWERSTD warning when using feature in newer language standard (#4168) (#4172). [Ethan Sifferman]
+* Add warning that timing controls in DPI exports are unsupported (#4238). [Krzysztof Bieganski, Antmicro Ltd]
+* Support std::process class (#4212). [Aleksander Kiryk, Antmicro Ltd]
+* Support inside expressions with strings and doubles (#4138) (#4139). [Krzysztof Boroński]
+* Support get_randstate/set_randstate class method functions.
+* Support for condition operator on class objects (#4214). [Ryszard Rozak, Antmicro Ltd]
+* Support array max (#4275). [Aleksander Kiryk, Antmicro Ltd]
+* Optimize VPI callValueCbs (#4155). [Hennadii Chernyshchyk]
+* Configure for faster C++ linking using 'mold', if it is installed.
+* Fix crash on duplicate imported modules (#3231). [Robert Balas]
+* Fix false WIDTHEXPAND on array declarations (#3959). [JOTEGO]
+* Fix marking overridden methods as coroutines (#4120) (#4169). [Krzysztof Bieganski, Antmicro Ltd]
+* Fix SystemC signal copy macro use (#4135). [Josep Sans]
+* Fix duplicate static names in blocks in functions (#4144) (#4160). [Stefan Wallentowitz]
+* Fix initialization order of initial static after function/task (#4159). [Kamil Rakoczy, Antmicro Ltd]
+* Fix linking AstRefDType if it has parameterized class ref (#4164) (#4170). [Ryszard Rozak, Antmicro Ltd]
+* Fix crash caused by $display() optimization (#4165) (#4166). [Tudor Timi]
+* Fix arrays of unpacked structs (#4173). [Risto Pejašinović]
+* Fix $fscanf of decimals overflowing variables (#4174). [Ahmed El-Mahmoudy]
+* Fix super.new missing data type (#4147). [Tudor Timi]
+* Fix missing class forward declarations (#4151). [Krzysztof Boroński]
+* Fix hashes of instances of parameterized classes (#4182). [Ryszard Rozak, Antmicro Ltd]
+* Fix forced assignments that override non-continuous assignments (#4183) (#4192). [Krzysztof Bieganski, Antmicro Ltd]
+* Fix wide structure VL_TOSTRING_W generation (#4188) (#4189). [Aylon Chaim Porat]
+* Fix references to members of parameterized base classes (#4196). [Ryszard Rozak, Antmicro Ltd]
+* Fix tracing undefined alignment (#4201) (#4288) [John Wehle]
+* Fix class specific same methods for AstVarScope, AstVar, and AstScope (#4203) (#4250). [John Wehle]
+* Fix dotted references in parameterized classes (#4206). [Ryszard Rozak, Antmicro Ltd]
+* Fix bit selections under parameterized classes (#4210). [Ryszard Rozak, Antmicro Ltd]
+* Fix duplicate std:: declaration with -I (#4215). [Harald Pretl]
+* Fix deep traversal of class inheritance timing (#4216). [Krzysztof Boroński]
+* Fix class parameters of enum types (#4219). [Ryszard Rozak, Antmicro Ltd]
+* Fix static methods with prototypes (#4220). [Ryszard Rozak, Antmicro Ltd]
+* Fix LATCH warning on function local variables (#4221) (#4284) [Julien Margetts]
+* Fix VCD scope types (#4227) (#4282). [Àlex Torregrosa]
+* Fix incorrect multi-driven lint warning (#4231) (#4248). [Adrien Le Masle]
+* Fix missing assignment for wide unpacked structs (#4233). [Jiamin Zhu]
+* Fix unpacked struct == and != operators (#4234) (#4240). [Risto Pejašinović]
+* Fix AstStructSel clean when data type is structure (#4241) (#4244). [Risto Pejašinović]
+* Fix function calls in with statements (#4245). [Ryszard Rozak, Antmicro Ltd]
+* Fix operator == for unpacked struct, if elements are VlUnpacked arrays (#4247). [Risto Pejašinović]
+* Fix STATIC lifetime for variables created from clocking items (#4262). [Krzysztof Boroński]
+* Fix names of foreach blocks (#4264). [Ryszard Rozak, Antmicro Ltd]
+* Fix iterated variables in foreach loops to have VAUTOM lifetimes (#4265). [Krzysztof Boroński]
+* Fix missing assignment for wide class members (#4267). [Jiamin Zhu]
+* Fix the global uses timing flag when forks exist (#4274). [Krzysztof Bieganski, Antmicro Ltd]
+* Fix struct redefinition (#4276). [Aleksander Kiryk, Antmicro Ltd]
+* Fix detection of wire/reg duplicates.
+* Fix false IMPLICITSTATIC on package functions.
+* Fix method calls on function return values.
+
+
+Verilator 5.010 2023-04-30
+==========================
+
+**Minor:**
+
+* Add --public-depth to force public to a certain instance depth (#3952). [Andrew Nolte]
+* Add --public-params flag (#3990). [Andrew Nolte]
+* Add CONSTRAINTIGN warning when constraint ignored.
+* Add STATICVAR warning and convert to automatic (#4018) (#4027) (#4030). [Ryszard Rozak, Antmicro Ltd]
+* Add error if class types don't match (#4064). [Ryszard Rozak, Antmicro Ltd]
+* Support class extends of package::class.
+* Support class srandom and class random stability.
+* Support class method calls without parenthesis (#3902) (#4082). [Srinivasan Venkataramanan]
+* Support method calls without parenthesis (#4034). [Ryszard Rozak, Antmicro Ltd]
+* Support parameterized return types of methods (#4122). [Ryszard Rozak, Antmicro Ltd]
+* Support parameterized class references in extends statement (#4146). [Ryszard Rozak, Antmicro Ltd]
+* Support complicated IEEE 'for' assignments.
+* Support $fopen as an expression.
+* Support ++/-- on dotted member variables.
+* Optimize static trigger evaluation (#4142). [Geza Lore, X-EPIC]
+* Optimize more xor trees (#4071). [Yutetsu TAKATSUKASA]
+* Change range order warning from LITENDIAN to ASCRANGE (#4010). [Iztok Jeras]
+* Change ZERODLY to a warning.
+* Fix random internal crashes (#666). [Dag Lem]
+* Fix install, standardization in cmake CMakeLists.txt (#3974). [Yu-Sheng Lin]
+* Fix UNDRIVEN warning seg fault (#3989). [Felix Neumärker]
+* Fix symbol entries when inheriting classes (#3995) (#3996). [Krzysztof Boroński]
+* Fix event controls reusing same variable (#4014). Kamil Rakoczy <[email protected]>
+* Fix push to dynamic queue in struct (#4015). [ezchi]
+* Fix names for blocks in do..while loop (#4019). [Ryszard Rozak, Antmicro Ltd]
+* Fix randomize on null field (#4023). [Ryszard Rozak, Antmicro Ltd]
+* Fix rand fields in base classes (#4025). [Ryszard Rozak, Antmicro Ltd]
+* Fix large return blocks with --comp-limit-blocks (#4028). [tenghtt]
+* Fix clocking block scope internal error (#4032). [Srinivasan Venkataramanan]
+* Fix false LATCH warning on --assert 'unique else if' (#4033) ($4054). [Jesse Taube]
+* Fix characters from DEFENV literals for Conda (#4035) (#4044). [Tim Snyder]
+* Fix info message prints under --assert (#4036) (#4053). [Srinivasan Venkataramanan]
+* Fix C++ compile errors when passing class refs as task argument (#4063). [Krzysztof Bieganski, Antmicro Ltd]
+* Fix NBAs inside fork-joins (#4050). [Aleksander Kiryk, Antmicro Ltd]
+* Fix task calls as fork statements (#4055). [Krzysztof Bieganski, Antmicro Ltd]
+* Fix _Vilp used before declaration (#4057) (#4062). [Josep Sans]
+* Fix incorrect optimization of bit op tree (#4059) (#4070). [Yutetsu TAKATSUKASA]
+* Fix parameters in a class body to be localparam (#4061). [Ryszard Rozak, Antmicro Ltd]
+* Fix interface generate begin (#4065). [Srinivasan Venkataramanan]
+* Fix tracing with awaits at end of block (#4075) (#4076). [Krzysztof Bieganski, Antmicro Ltd]
+* Fix sense expression variable naming (#4081). [Kamil Rakoczy]
+* Fix importing symbols from base class (#4084). [Ryszard Rozak, Antmicro Ltd]
+* Fix false error on new const assignment (#4098). [Tudor Timi]
+* Fix unpacked structs under classes (#4102). [Tudor Timi]
+* Fix variables in class methods to be automatic (#4111) (#4137). [Peter Monsson]
+* Fix to use parallel build for projects with a lot of files (#4116). [Krzysztof Boroński]
+* Fix including __Syms header in generated C++ files (#4123). [Krzysztof Boroński]
+* Fix systemc namespace issues (#4126) (#4127). [Eyck Jentzsch]
+* Fix class param extends A=B (#4128). [Ryszard Rozak, Antmicro Ltd]
+* Fix missing begin block hierarchy in --xml-only cells section (#4129) (#4133). [Risto Pejašinović]
+* Fix resolution of class lvalues after parameterization (#4131). [Krzysztof Boroński]
+* Fix DFG error on $countbits (#4101) (#4143). [Paul Donahue]
+* Fix duplicating parameter class types (#4115). [Ryszard Rozak, Antmicro Ltd]
+* Fix class extend param references (#4136).  [Ryszard Rozak, Antmicro Ltd]
+* Fix -CFLAGS to allow overriding optimization levels (#4140). [Peter Monsson]
+* Fix DPI function type alias (#4148) (#4149). [Toru Niina]
+* Fix deleting unused parameterized classes (#4150). [Ryszard Rozak, Antmicro Ltd]
+* Fix false ENUMVALUE on expressions and arrays.
+* Fix unnecessary verilated_std.sv waivers in --waiver-output.
+
+
 Verilator 5.008 2023-03-04
 ==========================

@@ -31,7 +261,6 @@ Verilator 5.008 2023-03-04
 * Support function calls without parenthesis (#3903) (#3902). [Ryszard Rozak, Antmicro Ltd]
 * Support class extending its parameter (#3904). [Ryszard Rozak, Antmicro Ltd]
 * Support static function variables (#3830). [Ryszard Rozak, Antmicro Ltd]
-* Support vpiDefName (#3906) (#3931). [Andrew Nolte]
 * Support recursive methods (#3987). [Ryszard Rozak, Antmicro Ltd]
 * Fix real parameters of infinity and NaN.
 * Fix pattern assignment to unpacked structs (#3510). [Mostafa Garnal]
@@ -41,8 +270,8 @@ Verilator 5.008 2023-03-04
 * Fix namespace fallback resolution (#3863) (#3942). [Aleksander Kiryk, Antmicro Ltd]
 * Fix std:: to be parsed first (#3864) (#3928). [Aleksander Kiryk, Antmicro Ltd]
 * Fix cmake warning if multiple SOURCES w/o PREFIX (#3916) (#3927). [Yoda Lee]
-* Fix paramaterized class function linkage (#3917). [Ryszard Rozak]
-* Fix static members of type aliases of a parametrized class (#3922). [Ryszard Rozak, Antmicro Ltd]
+* Fix parameterized class function linkage (#3917). [Ryszard Rozak]
+* Fix static members of type aliases of a parameterized class (#3922). [Ryszard Rozak, Antmicro Ltd]
 * Fix class extend parameter dot case (#3926). [Ryszard Rozak, Antmicro Ltd]
 * Fix MsWin missing directory exception, and ::std (#3928) (#3933) (#3935). [Kritik Bhimani]
 * Fix very long VPI signal names (#3929). [Marlon James]
@@ -54,13 +283,13 @@ Verilator 5.008 2023-03-04
 * Fix CMake bad C identifiers (#3948) (#3951). [Zixi Li]
 * Fix build on HP PA architecture (#3954). [John David Anglin]
 * Fix date on the front page of verilator.pdf (#3956) (#3957). [Larry Doolittle]
-* Fix dicts declared with ref type (#3960). [Ryszard Rozak, Antmicro Ltd]
+* Fix associative arrays declared with ref type (#3960). [Ryszard Rozak, Antmicro Ltd]
 * Fix missing error on negative replicate (#3963). [Benjamin Menküc]
 * Fix self references to parameterized classes (#3962). [Ryszard Rozak, Antmicro Ltd]
 * Fix LITENDIAN warning is backwards (#3966) (#3967). [Cameron Kirk]
 * Fix subsequent parameter declarations (#3969). [Ryszard Rozak, Antmicro Ltd]
 * Fix timing delays to not truncate below 64 bits (#3973) (#3982). [Felix Neumärker]
-* Fix cmake on macOS to mark weak symbols with -U linker flag (#3978) (#3979). [Peter Debacker]
+* Fix cmake on MacOS to mark weak symbols with -U linker flag (#3978) (#3979). [Peter Debacker]
 * Fix UNDRIVEN warning seg fault (#3989). [Felix Neumärker]
 * Fix coverage of class methods (#3998). [Tim Paine]
 * Fix packed array structure replication.
@@ -80,7 +309,7 @@ Verilator 5.006 2023-01-22
 * Support import/export lists in modport (#3886). [Gökçe Aydos]
 * Support class queue equality (#3895). [Ilya Barkov]
 * Support type case and type equality comparisons.
-* Add IMPLICITSTATIC warning when a ftask/function is implicitly static (#3839). [Ryszard Rozak, Antmicro Ltd]
+* Add IMPLICITSTATIC warning when a task/function is implicitly static (#3839). [Ryszard Rozak, Antmicro Ltd]
 * Add VL_VALUE_STRING_MAX_WORDS override (#3869). [Andrew Nolte]
 * Optimize expansion of extend operators.
 * Internal multithreading tests. [Mariusz Glebocki, et al, Antmicro Ltd]
@@ -94,7 +323,7 @@ Verilator 5.006 2023-01-22
 * Fix self references when param class instantiated (#3833). [Ryszard Rozak, Antmicro Ltd]
 * Fix memory leak in V3Sched, etc. (#3834). [Geza Lore]
 * Fix compatibility with musl libc / Alpine Linux (#3845). [Sören Tempel]
-* Fix empty case items crash (#3851). [rporter]
+* Fix empty case items crash (#3851). [Rich Porter]
 * Fix VL_CPU_RELAX on MIPS/Armel/s390/sparc (#3843) (#3891). [Kamil Rakoczy]
 * Fix module parameter name collision (#3854) (#3855). [James Shi]
 * Fix unpacked array expansion (#3861). [Joey Liu]
@@ -424,17 +424,15 @@ YAPF_FLAGS = -i
 yapf:
 	$(YAPF) $(YAPF_FLAGS) $(PY_FILES)

-FLAKE8 = flake8
-FLAKE8_FLAGS = \
-	--extend-exclude=fastcov.py \
-	--ignore=E123,E129,E251,E402,E501,W503,W504,E701
-
 PYLINT = pylint
 PYLINT_FLAGS = --score=n --disable=R0801

+RUFF = ruff
+RUFF_FLAGS = check --ignore=E402,E501,E701
+
 lint-py:
-	-$(FLAKE8) $(FLAKE8_FLAGS) $(PY_PROGRAMS)
 	-$(PYLINT) $(PYLINT_FLAGS) $(PY_PROGRAMS)
+	-$(RUFF) $(RUFF_FLAGS) $(PY_PROGRAMS)

 format-pl-exec:
 	-chmod a+x test_regress/t/*.pl
@@ -451,8 +449,8 @@ install-msg:

 IN_WILD := ${srcdir}/*.in ${srcdir}/*/*.in

-# autoheader might not change config_build.h.in, so touch it
-${srcdir}/config_build.h: ${srcdir}/config_build.h.in configure
+# autoheader might not change config_package.h.in, so touch it
+${srcdir}/config_package.h: ${srcdir}/config_package.h.in configure
 	cd ${srcdir} && autoheader
 	touch $@
 Makefile: Makefile.in config.status $(IN_WILD)
@@ -1,12 +1,16 @@
 .. Github doesn't render images unless absolute URL
 .. Do not know of a conditional tag, "only: github" nor "github display" works

+.. image:: https://img.shields.io/badge/Website-Verilator.org-181717.svg
+    :target: https://verilator.org
 .. image:: https://img.shields.io/badge/License-LGPL%20v3-blue.svg
-    :target: https://www.gnu.org/licenses/lgpl-3.0]
+    :target: https://www.gnu.org/licenses/lgpl-3.0
 .. image:: https://img.shields.io/badge/License-Artistic%202.0-0298c3.svg
    :target: https://opensource.org/licenses/Artistic-2.0
 .. image:: https://repology.org/badge/tiny-repos/verilator.svg?header=distro%20packages
    :target: https://repology.org/project/verilator/versions
+.. image:: https://img.shields.io/docker/pulls/verilator/verilator
+    :target: https://hub.docker.com/r/verilator/verilator
 .. image:: https://api.codacy.com/project/badge/Grade/fa78caa433c84a4ab9049c43e9debc6f
    :target: https://www.codacy.com/gh/verilator/verilator
 .. image:: https://codecov.io/gh/verilator/verilator/branch/master/graph/badge.svg
@@ -57,17 +61,16 @@ files, the "Verilated" code.

 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.
+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 a closed-source Verilog simulator, needs 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.
+designs, Verilator is the tool for you.


 Performance
@@ -83,11 +86,11 @@ as `Icarus Verilog`_. Another 2-10x speedup might be gained from
 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,
+closed-source Verilog simulators (e.g., Carbon Design Systems Carbonator,
 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.
+simulation cycles/dollar.


 Installation & Documentation
@@ -372,6 +372,7 @@ detailed descriptions of these arguments.
    --make <build-tool>         Generate scripts for specified build tool
     -MAKEFLAGS <flags>         Arguments to pass to make during --build
    --main                      Generate C++ main() file
+    --main-top-name             Specify top name passed to Verilated model in generated C++ main
    --max-num-width <value>     Maximum number width (default: 64K)
    --Mdir <directory>          Name of output object directory
    --MMD                       Create .d dependency files
@@ -404,6 +405,7 @@ detailed descriptions of these arguments.
    --protect-key <key>         Key for symbol protection
    --protect-lib <name>        Create a DPI protected library
    --public                    Debugging; see docs
+    --public-params             Mark all parameters as public_flat
    --public-flat-rw            Mark all variables, etc as public_flat_rw
     -pvalue+<name>=<value>     Overwrite toplevel parameter
    --quiet-exit                Don't print the command on failure
@@ -438,6 +440,7 @@ detailed descriptions of these arguments.
    --trace-params              Enable tracing of parameters
    --trace-structs             Enable tracing structure names
    --trace-threads <threads>   Enable FST waveform creation on separate threads
+    --no-trace-top              Do not emit traces for signals in the top module generated by verilator
    --trace-underscore          Enable tracing of _signals
     -U<var>                    Undefine preprocessor define
    --no-unlimited-stack        Don't disable stack size limit
@@ -61,7 +61,7 @@ if [ "$CI_BUILD_STAGE_NAME" = "build" ]; then
    sudo apt-get update
    sudo apt-get install ccache help2man libfl-dev ||
    sudo apt-get install ccache help2man libfl-dev
-    if [ "$CI_RUNS_ON" != "ubuntu-22.04" ]; then
+    if [ "$CI_RUNS_ON" = "ubuntu-20.04" ]; then
      # Some conflict of libunwind verison on 22.04, can live without it for now
      sudo apt-get install libgoogle-perftools-dev ||
      sudo apt-get install libgoogle-perftools-dev
@@ -70,6 +70,10 @@ if [ "$CI_BUILD_STAGE_NAME" = "build" ]; then
      sudo apt-get install libsystemc libsystemc-dev ||
      sudo apt-get install libsystemc libsystemc-dev
    fi
+    if [ "$CI_RUNS_ON" = "ubuntu-22.04" ]; then
+      sudo apt-get install bear mold ||
+      sudo apt-get install bear mold
+    fi
    if [ "$COVERAGE" = 1 ]; then
      yes yes | sudo cpan -fi Parallel::Forker
    fi
@@ -102,8 +106,8 @@ elif [ "$CI_BUILD_STAGE_NAME" = "test" ]; then
    sudo apt-get install gdb gtkwave lcov libfl-dev ccache
    # Required for test_regress/t/t_dist_attributes.pl
    if [ "$CI_RUNS_ON" = "ubuntu-22.04" ]; then
-      sudo apt-get install libclang-dev ||
-      sudo apt-get install libclang-dev
+      sudo apt-get install libclang-dev mold ||
+      sudo apt-get install libclang-dev mold
      pip3 install clang==14.0
    fi
    if [ "$CI_RUNS_ON" = "ubuntu-20.04" ] || [ "$CI_RUNS_ON" = "ubuntu-22.04" ]; then
@@ -19,10 +19,16 @@ RUN apt-get update \
                        ccache \
                        flex \
                        git \
+                        help2man \
+                        libfl2 \
                        libfl-dev \
                        libgoogle-perftools-dev \
+                        numactl \
                        perl \
+                        perl-doc \
                        python3 \
+                        zlib1g \
+                        zlib1g-dev \
    && apt-get clean \
    && rm -rf /var/lib/apt/lists/*

@@ -39,7 +45,7 @@ RUN git clone "${REPO}" verilator && \
    git checkout "${SOURCE_COMMIT}" && \
    autoconf && \
    ./configure && \
-    make -j "$(nproc)" && \
+    make && \
    make install && \
    cd .. && \
    rm -r verilator
@@ -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

-# When releasing, also update header of Changes file,
+# When releasing, also update header of Changes file, and CmakeLists.txt,
 # 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],[5.008 2023-03-04],
+AC_INIT([Verilator],[5.016 2023-09-16],
        [https://verilator.org],
        [verilator],[https://verilator.org])

-AC_CONFIG_HEADERS(src/config_build.h)
+AC_CONFIG_HEADERS(src/config_package.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
@@ -68,7 +68,7 @@ AC_MSG_CHECKING(whether to use -m32)
 AC_ARG_ENABLE([m32],
              [AS_HELP_STRING([--enable-m32],
                              [Use -m32 for all compilation and link,
-                               including Verialtor and generated models.])],
+                               including Verilator and generated models.])],
              [case "${enableval}" in
                yes) CFG_ENABLE_M32=yes ;;
                no)  CFG_ENABLE_M32=no ;;
@@ -470,6 +470,10 @@ m4_foreach([ldflag], [
 AC_SUBST(CFG_LDLIBS_THREADS)
 AC_SUBST(CFG_LDFLAGS_THREADS_CMAKE)

+# If 'mold' is installed, use it to link for faster buildtimes
+_MY_LDLIBS_CHECK_OPT(CFG_LDFLAGS_SRC, -fuse-ld=mold)
+_MY_LDLIBS_CHECK_OPT(CFG_LDFLAGS_VERILATED, -fuse-ld=mold)
+
 # When linking partially statically
 if test "$CFG_ENABLE_PARTIAL_STATIC" = "yes"; then
  _MY_LDLIBS_CHECK_OPT(CFG_LDFLAGS_SRC, -static-libgcc)
@@ -480,6 +484,7 @@ else
  LTCMALLOC=-ltcmalloc_minimal
 fi
 AC_SUBST(CFG_LDFLAGS_SRC)
+AC_SUBST(CFG_LDFLAGS_VERILATED)

 # The pthread library is required by tcmalloc, so add it if it exists. If it
 # does not, the tcmalloc check below will fail anyway, and linking against
@@ -10,9 +10,12 @@ contributions flow more efficiently.
 Did you find a bug?
 -------------------

- Please **Ensure the bug was not already reported** by searching
+- Please **ensure the bug was not already reported** by searching
  `Verilator Issues <https://verilator.org/issues>`__.

+- Please **download the latest development GitHub version**, build, and see
+  if the issue has been fixed.
+
 - If you're unable to find an open issue addressing the problem, `open a
  new Verilator issue <https://verilator.org/issues/new>`__.

@@ -20,21 +23,28 @@ Did you find a bug?
    demonstrating the bug and expected behavior that is not occurring.

  - The ideal example works against other simulators, and is in the
-    test_regress/t test format, as described in `docs/internals
-    <internals.rst>`__.
+    test_regress/t test format, as described in
+    `Verilator Internals Documentation
+    <https://github.com/verilator/verilator/blob/master/docs/internals.rst>`__.


 Did you write a patch that fixes a bug?
 ---------------------------------------

- Please `Open a new issue <https://verilator.org/issues/new>`__.
+- Please `Open a new Verilator issue <https://verilator.org/issues/new>`__
+  if there is not one already describing the bug.

- You may attach a patch to the issue, or (preferred) may request a
-  GitHub pull request.
+- Please `Open a Verilator pull request
+  <https://github.com/verilator/verilator/pulls>`__.

-  - Verilator uses GitHub Actions to provide continuous integration.  You
-    may want to enable Actions on your GitHub branch to ensure your changes
-    keep the tests passing. See `docs/internals <internals.rst>`__.
+- See the coding conventions, and other developer information in
+  ``docs/internals.rst`` in the distribution, or as rendered at
+  `Verilator Internals Documentation
+  <https://github.com/verilator/verilator/blob/master/docs/internals.rst>`__.
+
+- Verilator uses GitHub Actions to provide continuous integration.  You
+  may want to enable Actions on your GitHub branch to ensure your changes
+  keep the tests passing.

 - Your source-code contributions must be certified as open source,
  under the `Developer Certificate of
@@ -56,13 +66,10 @@ Did you write a patch that fixes a bug?
    contribution.

 - Your test contributions are generally considered released into the
-  Creative Commons Public Domain (CC0), unless you request otherwise or
+  Creative Commons Public Domain (CC0), unless you request otherwise, or
  put a GNU/Artistic license on your file.

- Most important is we get your patch. If you'd like to clean up
-  indentation and related issues ahead of our feedback, that is
-  appreciated; please see the coding conventions in `docs/internals
-  <internals.rst>`__.
+- Most important is we get your patch.


 Do you have questions?
@@ -12,8 +12,12 @@ Alex Chadwick
 Aliaksei Chapyzhenka
 Ameya Vikram Singh
 Andreas Kuster
+Andrei Kostovski
+Andrew Miloradovsky
 Andrew Nolte
+Anthony Donlon
 Arkadiusz Kozdra
+Aylon Chaim Porat
 Cameron Kirk
 Chris Randall
 Chuxuan Wang
@@ -24,14 +28,20 @@ David Horton
 David Metz
 David Stanford
 David Turner
+Don Williamson
 Drew Ranck
 Drew Taussig
 Driss Hafdi
 Edgar E. Iglesias
 Eric Rippey
+Ethan Sifferman
+Eyck Jentzsch
 Fan Shupei
+february cozzocrea
 Felix Neumärker
 Felix Yan
+Frans Skarman
+G-A. Kamendje
 Garrett Smith
 Geza Lore
 Gianfranco Costamagna
@@ -40,16 +50,16 @@ Gökçe Aydos
 Graham Rushton
 Guokai Chen
 Gustav Svensk
-G-A. Kamendje
 Harald Heckmann
+Hennadii Chernyshchyk
 Howard Su
 Huang Rui
 Huanghuang Zhou
 HungMingWu
 HyungKi Jeong
+Ilya Barkov
 Iru Cai
 Ivan Vnučec
-Ilya Barkov
 Iztok Jeras
 Jake Merdich
 James Hanlon
@@ -61,15 +71,21 @@ Jamie Iles
 Jan Van Winkel
 Jean Berniolles
 Jeremy Bennett
+Jesse Taube
 Jevin Sweval
 Jiacheng Qian
+Jiamin Zhu
 Jiuyang Liu
 Joey Liu
 John Coiner
 John Demme
+John Wehle
 Jonathan Drolet
+Jose Loyola
+Josep Sans
 Joseph Nwabueze
 Josh Redford
+Julian Daube
 Julie Schwartz
 Julien Margetts
 Kaleb Barrett
@@ -79,6 +95,7 @@ Keith Colbert
 Kevin Kiningham
 Kritik Bhimani
 Krzysztof Bieganski
+Krzysztof Boronski
 Krzysztof Boroński
 Kuba Ober
 Larry Doolittle
@@ -105,6 +122,7 @@ Mostafa Gamal
 Nandu Raj
 Nathan Kohagen
 Nathan Myers
+Oleh Maksymenko
 Patrick Stewart
 Paul Wright
 Pawel Sagan
@@ -119,23 +137,29 @@ Qingyao Sun
 Rafal Kapuscik
 Raynard Qiao
 Richard Myers
+Risto Pejašinović
+Robert Balas
 Rupert Swarbrick
 Ryszard Rozak
 Samuel Riedel
 Sean Cross
 Sebastien Van Cauwenberghe
 Sergi Granell
+Srinivasan Venkataramanan
 Stefan Wallentowitz
 Stephen Henry
 Steven Hugg
 Sören Tempel
 Teng Huang
+Tim Hutt
 Tim Snyder
 Tobias Rosenkranz
 Tobias Wölfel
 Todd Strader
 Tomasz Gorochowik
 Topa Topino
+Toru Niina
+Tudor Timi
 Tymoteusz Blazejczyk
 Udi Finkelstein
 Unai Martinez-Corral
@@ -143,15 +167,17 @@ Varun Koyyalagunta
 Vassilis Papaefstathiou
 Veripool API Bot
 Victor Besyakov
+Vito Gamberini
 William D. Jones
 Wilson Snyder
 Xi Zhang
 Yinan Xu
 Yoda Lee
 Yossi Nivin
+Yu-Sheng Lin
 Yuri Victorovich
 Yutetsu TAKATSUKASA
-Yu-Sheng Lin
 Yves Mathieu
 Zhanglei Wang
 Zixi Li
+أحمد المحمودي
@@ -18,12 +18,16 @@
 RST2HTML = rst2html
 PYTHON3 = python3
 DOXYGEN = doxygen
-SPHINXOPTS ?= -c guide
 SPHINXBUILD ?= sphinx-build

 SOURCEDIR = guide
 BUILDDIR = _build

+SPHINXOPTS ?= -c guide
+ifneq ($(VERILATOR_ANALYTICS_ID),)
+SPHINXOPTS += -D html_theme_options.analytics_id=$(VERILATOR_ANALYTICS_ID)
+endif
+
 ######################################################################

 .SUFFIXES:
@@ -31,7 +31,7 @@ def get_vlt_version():
            if match:
                try:
                    data = os.popen('git log -n 1 --pretty=%cs').read()
-                except Exception:
+                except Exception:  # pylint: disable=broad-except
                    data = ""  # fallback, and Sphinx will fill in today's date
                return "Devel " + match.group(1), data
    return "unknown", "unknown"
@@ -115,7 +115,6 @@ html_theme = 'sphinx_rtd_theme'
 html_theme_path = [sphinx_rtd_theme.get_html_theme_path()]

 html_theme_options = {
-    'analytics_id': 'G-D27B0C9QEB',
    'logo_only': True,
    'style_nav_header_background': "#45acf8",  # Default is #2980B9
    # 'canonical_url':
@@ -120,6 +120,52 @@ code.  This is a feature, as using the SystemC pin interconnect scheme
 everywhere would reduce performance by an order of magnitude.


+Verilated API
+=============
+
+The API to a Verilated model is the C++ headers in the include/ directory
+in the distribution.  These headers use Doxygen comments, `///` and `//<`,
+to indicate and document those functions that are part of the Verilated
+public API.
+
+Process-Level Clone APIs
+--------------------------
+
+Modern operating systems support process-level clone (a.k.a copying, forking)
+with system call interfaces in C/C++, e.g., :code:`fork()` in Linux.
+
+However, after cloning a parent process, some resources cannot be inherited
+in the child process. For example, in POSIX systems, when you fork a process,
+the child process inherits all the memory of the parent process. However,
+only the thread that called fork is replicated in the child process. Other
+threads are not.
+
+Therefore, to support the process-level clone mechanisms, Verilator supports
+:code:`prepareClone()` and :code:`atClone()` APIs to allow the user to manually
+re-construct the model in the child process. The two APIs handle all necessary
+resources required for releasing and re-initializing before and after cloning.
+
+The two APIs are supported in the verilated models. Here is an example of usage
+with Linux :code:`fork()` and :code:`pthread_atfork` APIs:
+
+.. code-block:: C++
+
+    // static function pointers to fit pthread_atfork
+    static auto prepareClone = [](){ topp->prepareClone(); };
+    static auto atClone = [](){ topp->atClone(); };
+
+    // in main function, register the handlers:
+    pthread_atfork(prepareClone, atClone, atClone);
+
+For better flexibility, you can also manually call the handlers before and
+after :code:`fork()`.
+
+With the process-level clone APIs, users can create process-level snapshots
+for the verilated models. While the Verilator save/restore option provides
+persistent and circuit-dependent snapshots, the process-level clone APIs
+enable in-memory, circuit-transparent, and highly efficient snapshots.
+
+
 Direct Programming Interface (DPI)
 ==================================

@@ -17,10 +17,10 @@ C++11 compiler support
  Verilator will require C++20 or newer compilers for both compiling
  Verilator and compiling all Verilated models no sooner than January 2025.

-Verilated_heavy.h
-  The legacy "verilated_heavy.h" include was replaced with just including
-  "verilated.h". Verilated_heavy.h is planned for removal no sooner than
-  July 2022.
+32-bit compiler support
+  Verilator currently regresses both 64-bit and 32-bit pointer modes (GCC's
+  `-m64` and `-m32`).  Support for 32-bit `-m32` mode will be deprecated no
+  sooner than January 2024.

 Option `-O<letter>`
  The debug `-O<letter>` options have been replaced with
@@ -91,9 +91,29 @@ associated programs.

 .. option:: VERILATOR_ROOT

-   Specifies the directory containing the distribution kit.  This is used
-   to find the executable, Perl library, and include files.  If not
-   specified, it will come from a default optionally specified at configure
-   time (before Verilator was compiled).  It should not be specified if
-   using a pre-compiled Verilator package as the hard-coded value should be
-   correct.  See :ref:`Installation`.
+   The ``VERILATOR_ROOT`` environment variable is used in several places:
+
+   * At ``./configure`` time: If set, it is embedded into the binary, and
+     at runtime if ``VERILATOR_ROOT`` is not set, the embedded value is
+     used for the runtime default.
+
+   * When ``verilator`` is run: If ``VERILATOR_ROOT`` is set it will be
+     used to find the ``verilator_bin`` executable (this is the actual
+     Verilator binary; ``verilator`` is a Perl wrapper). If not set, the
+     ``verilator`` script uses other methods to find ``verilator_bin``
+     (looking in the same directory and falling back to ``$PATH``).
+
+   * When ``make`` is run on the Makefile generated by ``verilator``: The
+     value of ``VERILATOR_ROOT`` (falling back to the value embedded in the
+     binary if not set) is used to find the include files
+     (``include/verilated.mk``).
+
+   If you are using a pre-compiled Verilator package, you should not need
+   to set ``VERILATOR_ROOT`` - the value embedded in the binary should be
+   correct.  In fact this option *does not work* with Verilator packages
+   that have been installed with ``make install``. If a Verilator package
+   has been installed using ``./configure --prefix=/some/path && make
+   install`` and then moved to another location, you cannot use
+   ``VERILATOR_ROOT`` to point to the new version.
+
+   See :ref:`Installation` for more details.
@@ -125,9 +125,12 @@ Summary:

   After generating the SystemC/C++ code, Verilator will invoke the
   toolchain to build the model library (and executable when :vlopt:`--exe`
-   is also used). Verilator manages the build itself, and for this --build
+   is also used).  Verilator manages the build itself, and for this --build
   requires GNU Make to be available on the platform.

+   :vlopt:`--build` cannot be specified when using :vlopt:`-E`,
+   :vlopt:`--dpi-hdr-only`, :vlopt:`--lint-only`, or :vlopt:`--xml-only`.
+
 .. option:: --build-dep-bin <filename>

   Rarely needed.  When a dependency (.d) file is created, this filename
@@ -808,6 +811,13 @@ Summary:

   See also :vlopt:`--binary`.

+.. option:: --main-top-name <string>
+
+   Specify the name passed to the Verilated model being constructed, in the
+   generated C++ main() function.
+
+   If the string ``"-"`` is used, no top level scope is added.
+
 .. option:: --max-num-width <value>

   Set the maximum number literal width (e.g., in 1024'd22 this
@@ -1101,6 +1111,18 @@ Summary:
   marking only those signals that need public_flat_rw is typically
   significantly better performing.

+.. option:: --public-depth <level>
+
+   Enables public as with :vlopt:`--public-flat-rw`, but only to the specified depth of modules.
+   It operates at the module maximum level, so if a module's cells are A.B.X and A.X, the
+   a --public-depth 3 must be used to make module X public, and both A.B.X and A.X will be public.
+
+.. option:: --public-params
+
+   Declares all parameters public as if they had
+   :code:`/*verilator public_flat_rd*/`
+   metacomments.
+
 .. option:: -pvalue+<name>=<value>

   Overwrites the given parameter(s) of the top-level module. See
@@ -1295,6 +1317,7 @@ Summary:
   This is not needed with standard designs with only one top.  See also
   :option:`MULTITOP` warning.

+
 .. option:: --trace

   Adds waveform tracing code to the model using VCD format. This overrides
@@ -1373,6 +1396,17 @@ Summary:
   This option is accepted, but has absolutely no effect with
   :vlopt:`--trace`, which respects :vlopt:`--threads` instead.

+.. option:: --no-trace-top
+
+   Disables tracing for the input and output signals in the top wrapper which
+   Verilator adds to the design. The signals are still traced in the original
+   verilog top modules.
+
+   When combined with :option:`--main-top-name` set to "-" or when the name of
+   the top module is set to "" in its constructor, the generated trace file
+   will have the verilog top module as its root, rather than another module
+   added by Verilator.
+
 .. option:: --trace-underscore

   Enable tracing of signals or modules that start with an
@@ -1455,8 +1489,11 @@ Summary:
   them systematically.

   The generated file is in the Verilator Configuration format, see
-   :ref:`Configuration Files`, and can directly be consumed by
-   Verilator. The standard file extension is ".vlt".
+   :ref:`Configuration Files`. The standard file extension is ".vlt".
+   These files can directly be consumed by Verilator, typically by placing
+   the filename as part of the Verilator command line options. Waiver files
+   need to be listed on the command line before listing the files they are
+   waiving.

 .. option:: -Wall

@@ -1501,13 +1538,15 @@ Summary:

 .. option:: -Wno-lint

-   Disable all lint-related warning messages, and all style warnings.  This is
-   equivalent to ``-Wno-ALWCOMBORDER -Wno-BSSPACE -Wno-CASEINCOMPLETE
-   -Wno-CASEOVERLAP -Wno-CASEX -Wno-CASTCONST -Wno-CASEWITHX -Wno-CMPCONST -Wno-COLONPLUS
-   -Wno-IMPLICIT -Wno-IMPLICITSTATIC -Wno-LITENDIAN -Wno-PINCONNECTEMPTY
-   -Wno-PINMISSING -Wno-SYNCASYNCNET -Wno-UNDRIVEN -Wno-UNSIGNED
-   -Wno-UNUSEDGENVAR -Wno-UNUSEDPARAM -Wno-UNUSEDSIGNAL
-   -Wno-WIDTH`` plus the list shown for Wno-style.
+   Disable all lint-related warning messages, and all style warnings.  This
+   is equivalent to ``-Wno-ALWCOMBORDER`` ``-Wno-ASCRANGE``
+   ``-Wno-BSSPACE`` ``-Wno-CASEINCOMPLETE`` ``-Wno-CASEOVERLAP``
+   ``-Wno-CASEX`` ``-Wno-CASTCONST`` ``-Wno-CASEWITHX`` ``-Wno-CMPCONST``
+   ``-Wno-COLONPLUS`` ``-Wno-IMPLICIT`` ``-Wno-IMPLICITSTATIC``
+   ``-Wno-PINCONNECTEMPTY`` ``-Wno-PINMISSING`` ``-Wno-STATICVAR``
+   ``-Wno-SYNCASYNCNET`` ``-Wno-UNDRIVEN`` ``-Wno-UNSIGNED``
+   ``-Wno-UNUSEDGENVAR`` ``-Wno-UNUSEDPARAM`` ``-Wno-UNUSEDSIGNAL``
+   ``-Wno-WIDTH``, plus the list shown for :vlopt:`-Wno-style`.

   It is strongly recommended that you clean up your code rather than using this
   option; it is only intended to be used when running test-cases of code
@@ -1515,12 +1554,13 @@ Summary:

 .. option:: -Wno-style

-   Disable all code style related warning messages (note that by default, they are
-   already disabled).  This is equivalent to ``-Wno-DECLFILENAME -Wno-DEFPARAM
-   -Wno-EOFNEWLINE -Wno-IMPORTSTAR -Wno-INCABSPATH -Wno-PINCONNECTEMPTY
-   -Wno-PINNOCONNECT -Wno-SYNCASYNCNET -Wno-UNDRIVEN
-   -Wno-UNUSEDGENVAR -Wno-UNUSEDPARAM -Wno-UNUSEDSIGNAL
-   -Wno-VARHIDDEN``.
+   Disable all code style related warning messages (note that by default,
+   they are already disabled).  This is equivalent to ``-Wno-DECLFILENAME``
+   ``-Wno-DEFPARAM`` ``-Wno-EOFNEWLINE`` ``-Wno-GENUNNAMED``
+   ``-Wno-IMPORTSTAR`` ``-Wno-INCABSPATH`` ``-Wno-PINCONNECTEMPTY``
+   ``-Wno-PINNOCONNECT`` ``-Wno-SYNCASYNCNET`` ``-Wno-UNDRIVEN``
+   ``-Wno-UNUSEDGENVAR`` ``-Wno-UNUSEDPARAM`` ``-Wno-UNUSEDSIGNAL``
+   ``-Wno-VARHIDDEN``.

 .. option:: -Wpedantic

@@ -1538,19 +1578,25 @@ Summary:

 .. option:: -Wwarn-lint

-   Enable all lint-related warning messages (note that by default, they are already
-   enabled), but do not affect style messages.  This is equivalent to
-   ``-Wwarn-ALWCOMBORDER -Wwarn-BSSPACE -Wwarn-CASEINCOMPLETE
-   -Wwarn-CASEOVERLAP -Wwarn-CASEX -Wwarn-CASTCONST -Wwarn-CASEWITHX -Wwarn-CMPCONST
-   -Wwarn-COLONPLUS -Wwarn-IMPLICIT -Wwarn-LITENDIAN
-   -Wwarn-PINMISSING -Wwarn-REALCVT -Wwarn-UNSIGNED -Wwarn-WIDTH``.
+   Enable all lint-related warning messages (note that by default, they are
+   already enabled), but do not affect style messages.  This is equivalent
+   to ``-Wwarn-ALWCOMBORDER`` ``-Wwarn-ASCRANGE`` ``-Wwarn-BSSPACE``
+   ``-Wwarn-CASEINCOMPLETE`` ``-Wwarn-CASEOVERLAP`` ``-Wwarn-CASEWITHX``
+   ``-Wwarn-CASEX`` ``-Wwarn-CASTCONST`` ``-Wwarn-CMPCONST``
+   ``-Wwarn-COLONPLUS`` ``-Wwarn-IMPLICIT`` ``-Wwarn-IMPLICITSTATIC``
+   ``-Wwarn-LATCH`` ``-Wwarn-MISINDENT`` ``-Wwarn-NEWERSTD``
+   ``-Wwarn-PINMISSING`` ``-Wwarn-REALCVT`` ``-Wwarn-STATICVAR``
+   ``-Wwarn-UNSIGNED`` ``-Wwarn-WIDTHTRUNC`` ``-Wwarn-WIDTHEXPAND``
+   ``-Wwarn-WIDTHXZEXPAND``.

 .. option:: -Wwarn-style

   Enable all code style-related warning messages.  This is equivalent to
-   ``-Wwarn ASSIGNDLY -Wwarn-DECLFILENAME -Wwarn-DEFPARAM -Wwarn-EOFNEWLINE
-   -Wwarn-INCABSPATH -Wwarn-PINNOCONNECT -Wwarn-SYNCASYNCNET -Wwarn-UNDRIVEN
-   -Wwarn-UNUSEDGENVAR -Wwarn-UNUSEDPARAM -Wwarn-UNUSEDSIGNAL -Wwarn-VARHIDDEN``.
+   ``-Wwarn-ASSIGNDLY`` ``-Wwarn-DECLFILENAME`` ``-Wwarn-DEFPARAM``
+   ``-Wwarn-EOFNEWLINE`` ``-Wwarn-GENUNNAMED`` ``-Wwarn-INCABSPATH``
+   ``-Wwarn-PINNOCONNECT`` ``-Wwarn-SYNCASYNCNET`` ``-Wwarn-UNDRIVEN``
+   ``-Wwarn-UNUSEDGENVAR`` ``-Wwarn-UNUSEDPARAM`` ``-Wwarn-UNUSEDSIGNAL``
+   ``-Wwarn-VARHIDDEN``.

 .. option:: --x-assign 0

@@ -356,8 +356,8 @@ Why do I get "undefined reference to \`VL_RAND_RESET_I' or \`Verilated::...'"?
 You need to link your compiled Verilated code against the
 :code:`verilated.cpp` file found in the include directory of the Verilator
 kit.  This is one target in the ``$(VK_GLOBAL_OBJS)`` make variable, which
-should be part of your Makefile's link rule.  If you use :vlopt:`--exe`,
-this is done for you.
+should be part of your Makefile's link rule.  If you use :vlopt:`--exe` or
+:vlopt:`--binary`, this is done for you.


 Is the PLI supported?
@@ -486,7 +486,7 @@ From the sc_main.cpp file, you'd then:

      #include "Vour.h"
      #include "Vour_our.h"
-      cout << "clock is " << top->our->clk << endl;
+      std::cout << "clock is " << top->our->clk << std::endl;


 In this example, clk is a bool you can read or set as any other variable.
@@ -126,8 +126,10 @@ In specific debug and other modes, it also creates:
     - Debugging graph files (from --debug)
   * - *{prefix}{misc}*\ .tree
     - Debugging files (from --debug)
-   * - {mod_prefix}_{each_verilog_base_filename}*\ .vpp
-     - Pre-processed verilog (from --debug)
+   * - *{prefix}*\ __inputs\ .vpp
+     - Pre-processed verilog for all files (from --debug)
+   * - *{prefix}*\ _ *{each_verilog_base_filename}*\ .vpp
+     - Pre-processed verilog for each file (from --debug)

 After running Make, the C++ compiler may produce the following:

@@ -39,7 +39,7 @@ In brief, to install from git:
 ::

   # Prerequisites:
-   #sudo apt-get install git perl python3 make autoconf g++ flex bison ccache
+   #sudo apt-get install git help2man perl python3 make autoconf g++ flex bison ccache
   #sudo apt-get install libgoogle-perftools-dev numactl perl-doc
   #sudo apt-get install libfl2  # Ubuntu only (ignore if gives error)
   #sudo apt-get install libfl-dev  # Ubuntu only (ignore if gives error)
@@ -104,6 +104,7 @@ for good performance:
 ::

   sudo apt-get install ccache  # If present at build, needed for run
+   sudo apt-get install mold  # If present at build, needed for run
   sudo apt-get install libgoogle-perftools-dev numactl

 The following is optional but is recommended for nicely rendered command line
@@ -124,9 +125,9 @@ Those developing Verilator itself may also want these (see internals.rst):

 ::

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

@@ -201,8 +202,9 @@ These are the installation options:
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

 Our personal favorite is to always run Verilator in-place from its Git
-directory. This allows the easiest experimentation and upgrading, and
-allows many versions of Verilator to co-exist on a system.
+directory (don't run ``make install``). This allows the easiest
+experimentation and upgrading, and allows many versions of Verilator to
+co-exist on a system.

 ::

@@ -211,17 +213,18 @@ allows many versions of Verilator to co-exist on a system.
   ./configure
   # Running will use files from $VERILATOR_ROOT, so no install needed

-Note after installing (below steps), a calling program or shell must set
-the environment variable :option:`VERILATOR_ROOT` to point to this Git
-directory, then execute ``$VERILATOR_ROOT/bin/verilator``, which will find
-the path to all needed files.
+Note after installing (see `Installation`_), a calling program or shell
+must set the environment variable :option:`VERILATOR_ROOT` to point to this
+Git directory, then execute ``$VERILATOR_ROOT/bin/verilator``, which will
+find the path to all needed files.


-2. Install into a specific location
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+2. Install into a Specific Prefix
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

-You may eventually be installing onto a project/company-wide "CAD" tools
-disk that may support multiple versions of every tool. Tell configure the
+You may be an OS package maintainer building a Verilator package, or you
+may eventually be installing onto a project/company-wide "CAD" tools disk
+that may support multiple versions of every tool. Tell configure the
 eventual destination directory name.  We recommend that the destination
 location include the Verilator version name:

@@ -232,7 +235,8 @@ location include the Verilator version name:
   # For the tarball, use the version number instead of git describe
   ./configure --prefix /CAD_DISK/verilator/`git describe | sed "s/verilator_//"`

-Note after installing (below steps), if you use `modulecmd
+Note after installing (see `Installation`_), you need to add the path to
+the ``bin`` directory to your ``PATH``. Or, if you use `modulecmd
 <http://modules.sourceforge.net/>`__, you'll want a module file like the
 following:

@@ -245,23 +249,7 @@ following:
   prepend-path PKG_CONFIG_PATH $install_root/share/pkgconfig


-3. Install into a Specific Path
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-
-You may eventually install Verilator into a specific installation prefix,
-as most GNU tools support:
-
-::
-
-   unset VERILATOR_ROOT      # if your shell is bash
-   unsetenv VERILATOR_ROOT   # if your shell is csh
-   ./configure --prefix /opt/verilator-VERSION
-
-Then after installing (below steps), you will need to add
-``/opt/verilator-VERSION/bin`` to your ``$PATH`` environment variable.
-
-
-4. Install System Globally
+3. Install System Globally
 ^^^^^^^^^^^^^^^^^^^^^^^^^^

 The final option is to eventually install Verilator globally, using
@@ -273,8 +261,8 @@ configure's default system paths:
   unsetenv VERILATOR_ROOT   # if your shell is csh
   ./configure

-Then after installing (below), the binaries should be in a location
-already in your ``$PATH`` environment variable.
+Then after installing (see `Installation`_), the binaries should be in a
+location already in your ``$PATH`` environment variable.


 Configure
@@ -44,7 +44,7 @@ The best place to get started is to try the :ref:`Examples`.
 .. [#] Verilog is defined by the `Institute of Electrical and Electronics
       Engineers (IEEE) Standard for Verilog Hardware Description
       Language`, Std. 1364, released in 1995, 2001, and 2005.  The
-       Verilator documentation uses the shorthand, e.g., "IEEE 1394-2005",
+       Verilator documentation uses the shorthand, e.g., "IEEE 1364-2005",
       to refer to the, e.g., 2005 version of this standard.

 .. [#] SystemVerilog is defined by the `Institute of Electrical and
@@ -143,7 +143,7 @@ Functional Coverage
 -------------------

 With :vlopt:`--coverage` or :vlopt:`--coverage-user`, Verilator will
-translate functional coverage points the user has inserted manually win
+translate functional coverage points the user has inserted manually in
 SystemVerilog code through into the Verilated model.

 Currently, all functional coverage points are specified using SystemVerilog
@@ -498,3 +498,20 @@ Clang.  The process in GCC 10 was as follows:
 Clang and GCC also support -fauto-profile, which uses sample-based
 feedback-directed optimization.  See the appropriate compiler
 documentation.
+
+
+.. _Runtime Debugging:
+
+Runtime Debugging
+=================
+
+To debug a Verilated executable, use the standard GNU debugger ``gdb`` or a
+similar tool. Typically you will want to have debugger symbols inserted by
+the compiler, assertions enabled in the C library, and assertions enabled
+in the Verilated library. (These options slow down the executable, so do
+this only when debugging.) To enable this, Verilate with:
+
+    -CFLAGS -ggdb  -LDFLAGS -ggdb  -CFLAGS -DVL_DEBUG=1  -CFLAGS -D_GLIBCXX_DEBUG
+
+The :vlopt:`-CFLAGS` and/or :vlopt:`-LDFLAGS` options pass arguments
+directly to the compiler or linker.
@@ -165,7 +165,7 @@ compiled on the different target system.

 To support this, none of the files that Verilator produces will reference
 any configure-generated build-system-specific files, such as
-:file:`config.h` (which is renamed in Verilator to :file:`config_build.h`
+:file:`config.h` (which is renamed in Verilator to :file:`config_package.h`
 to reduce confusion.)  The disadvantage of this approach is that
 :file:`include/verilatedos.h` must self-detect the requirements of the
 target system, rather than using configure.
@@ -97,6 +97,24 @@ List Of Warnings
   simulate correctly.


+.. option:: ASCRANGE
+
+   .. TODO better example
+
+   Warns that a packed vector is declared with ascending bit range
+   (i.e. [0:7]).  Descending bit range is now the overwhelming standard,
+   and ascending ranges are now thus often due to simple oversight
+   instead of intent (a notable exception is the OpenPOWER code base).
+
+   It also warns that an instance is declared with ascending range
+   (i.e. [0:7] or [7]) and is connected to an N-wide signal.
+   The bits will likely be in the reversed order from what people may expect
+   (i.e., instance [0] will connect to signal bit [N-1] not bit [0]).
+
+   Ignoring this warning will only suppress the lint check; it will
+   simulate correctly.
+
+
 .. option:: ASSIGNDLY

   .. TODO better example
@@ -378,6 +396,16 @@ List Of Warnings
   simulators.


+.. option:: CONSTRAINTIGN
+
+   Warns that Verilator does not support :code:`constraint`,
+   :code:`constraint_mode`, or :code:`rand_mode`, and the construct was are
+   ignored.
+
+   Ignoring this warning may make Verilator randomize() simulations differ
+   from other simulators.
+
+
 .. option:: CONTASSREG

   .. TODO better example
@@ -642,6 +670,52 @@ List Of Warnings
   used as a clock.


+.. option:: GENUNNAMED
+
+   Warns that a generate block was unnamed and "genblk" will be used per
+   IEEE.
+
+   The potential issue is that adding additional generate blocks will
+   renumber the assigned names, which may cause eventual problems with
+   synthesis constraints or other tools that depend on hierarchical paths
+   remaining consistent.
+
+   Blocks that are empty may not be reported with this warning, as no
+   scopes are created for empty blocks, so there is no harm in having them
+   unnamed.
+
+   Disabled by default as this is a code-style warning; it will simulate
+   correctly.
+
+   .. code-block:: sv
+      :linenos:
+      :emphasize-lines: 2
+
+         generate
+            if (PARAM == 1) begin  //<--- Warning
+            end
+
+   Results in:
+
+   .. code-block::
+
+         %Warning-GENUNNAMED: example.v:2:9: Unnamed generate block (IEEE 1800-2017 27.6)
+
+   To fix this assign a label (often with the naming convention prefix of
+   :code:`gen_` or :code:`g_`), for example:
+
+   .. code-block:: sv
+      :linenos:
+      :emphasize-lines: 2
+
+         generate
+            if (PARAM == 1) begin : gen_param_1  //<--- Repaired
+            end
+
+   Other tools with similar warnings: Verible's generate-label, "All
+   generate block statements must have a label."
+
+
 .. option:: HIERBLOCK

   Warns that the top module is marked as a hierarchy block by the
@@ -738,14 +812,17 @@ List Of Warnings

   This is a warning because the static default differs from C++, differs
   from class member function/tasks.  Static is a more dangerous default
-   then automatic as static prevents the function from being reinterant,
+   then automatic as static prevents the function from being reentrant,
   which may be a source of bugs, and/or performance issues.

-   If the function does not require static behavior, change it to "function
-   automatic".
+   If the function is in a module, and does not require static behavior,
+   change it to "function automatic".

-   If the function requires static behavior, change it to "function
-   static".
+   If the function is in a module, and requires static behavior, change it
+   to "function static".
+
+   If the function is in a package, it defaults to static, and label the
+   function's variables as static.

   Ignoring this warning will only suppress the lint check; it will
   simulate correctly.
@@ -845,23 +922,111 @@ List Of Warnings
   Ignoring this warning will only suppress the lint check; it will
   simulate correctly.

+.. option:: LIFETIME
+
+   Error when a variable is referenced in a process that can outlive the process
+   in which it was declared. This can happen when using 'fork..join_none' or
+   'fork..join_any' blocks, which spawn process that can outlive their parents.
+   This error occurs only when Verilator can't replace the reference with a
+   reference to copy of this variable, local to the forked process. For example:
+
+   .. code-block:: sv
+      :linenos:
+      :emphasize-lines: 3
+
+         task foo(int local_var);
+            fork
+               #10 local_var++;
+               #20 $display("local_var = %d", local_var);
+            join_none
+         endtask
+
+   In the example above 'local_var' exists only within scope of 'foo', once foo
+   finishes, the stack frame containing 'i' gets removed. However, the process
+   forked from foo continues, as it contains a delay. After 10 units of time
+   pass, this process attempts to modify 'local_var'. However, this variable no
+   longer exits. It can't be made local to the forked process upon spawning, because
+   it's modified and can be referenced somewhere else, for example in the other
+   forked process, that was delayed by 20 units of time in this example. Thus,
+   there's no viable stack allocation for it.
+
+   In order to fix it, if the intent is not to share the variable's state outside
+   of the process, then create a local copy of the variable.
+
+   For example:
+
+   .. code-block:: sv
+      :linenos:
+      :emphasize-lines: 4
+
+         task foo(int local_var);
+            fork
+               #10 begin
+                  int forked_var = local_var;
+                  forked_var++;
+               end
+               #20 begin
+                  // Note that we are going to print the original value here,
+                  // as `forked_var`is a local copy that was initialized while
+                  // `foo` was still alive.
+                  int forked_var = local_var;
+                  $display("forked_var = %d", forked_var)
+               end
+            join_none
+         endtask
+
+   If you need to share its state, another strategy is to ensure it's allocated
+   statically:
+
+   .. code-block:: sv
+      :linenos:
+      :emphasize-lines: 1
+
+         int static_var;
+
+         task foo();
+            fork
+               #10 static_var++;
+               #20 $display("static_var = %d", static_var);
+            join_none
+         endtask
+
+   However, if you need to be able to instantiate at runtime, the solution would be to
+   wrap it in an object, since the forked process can hold a reference to that object
+   and ensure that the variable stays alive this way:
+
+   .. code-block:: sv
+      :linenos:
+      :emphasize-lines: 2
+
+         class Wrapper;
+            int m_var;
+
+            // Here we implicitly hold a reference to `this`
+            task foo();
+               fork
+                  #10 m_var++;
+                  #20 $display("this.m_var = %d", m_var);
+               join_none
+            endtask
+         endclass
+
+         // Here we explicitly hold a handle to an object
+         task bar(Wrapper wrapper);
+            fork
+               #10 wrapper.m_var++;
+               #20 $display("wrapper.m_var = %d", wrapper.m_var);
+            join_none
+         endtask

 .. option:: LITENDIAN

   .. TODO better example

-   Warns that a packed vector is declared with big endian bit numbering
-   (i.e. [0:7]).  Little endian bit numbering is now the overwhelming
-   standard, and big numbering is now thus often due to simple oversight
-   instead of intent.
-
-   It also warns that an instance is declared with big endian range
-   (i.e. [0:7] or [7]) and is connected to an N-wide signal.
-   The bits will likely be backward from what people may expect
-   (i.e., instance [0] will connect to signal bit [N-1] not bit [0]).
-
-   Ignoring this warning will only suppress the lint check; it will
-   simulate correctly.
+   The naming of this warning is in contradiction with the common
+   interpretation of little endian. It was therefore renamed to
+   :option:`ASCRANGE`. While :option:`LITENDIAN` remains for
+   backwards compatibility, new projects should use :option:`ASCRANGE`.


 .. option:: MINTYPMAX
@@ -874,6 +1039,51 @@ List Of Warnings
   unsupported. Verilator uses only the typical delay value.


+.. option:: MISINDENT
+
+   Warns that the indentation of a statement is misleading, suggesting the
+   statement is part of a previous :code:`if` or :code:`while` block while
+   it is not.
+
+   Verilator suppresses this check when there is an inconsistent mix of
+   spaces and tabs, as it cannot ensure the width of tabs.  Verilator also
+   ignores blocks with :code:`begin`/:code:`end`, as the :code:`end`
+   visually indicates the earlier statement's end.
+
+   Ignoring this warning will only suppress the lint check; it will
+   simulate correctly.
+
+   For example
+
+   .. code-block:: sv
+      :linenos:
+      :emphasize-lines: 3
+
+         if (something)
+            statement_in_if;
+            statement_not_in_if;  //<--- Warning
+
+   Results in:
+
+   .. code-block::
+
+         %Warning-MISINDENT: example.v:3:9: Misleading indentation
+
+   To fix this repair the indentation to match the correct earlier
+   statement, for example:
+
+   .. code-block:: sv
+      :linenos:
+      :emphasize-lines: 3
+
+         if (something)
+            statement_in_if;
+         statement_not_in_if;  //<--- Repaired
+
+   Other tools with similar warnings: GCC -Wmisleading-indentation,
+   clang-tidy readability-misleading-indentation.
+
+
 .. option:: MODDUP

   .. TODO better example
@@ -952,6 +1162,21 @@ List Of Warnings
   (neither :vlopt:`--timing` nor :vlopt:`--no-timing` option was provided).


+.. option:: NEWERSTD
+
+   Warns that a feature requires a newer standard of Verilog or SystemVerilog
+   than the one specified by the :vlopt:`--language` option. For example, unsized
+   unbased literals (`'0`, `'1`, `'z`, `'x`) require 1800-2005 or later.
+
+   To avoid this warning, use a Verilog or SystemVerilog standard that
+   supports the feature. Alternatively, modify your code to use a different
+   syntax that is supported by the Verilog/SystemVerilog standard specified
+   by the :vlopt:`--language` option.
+
+   Ignoring this warning will only suppress the lint check; it will
+   simulate correctly.
+
+
 .. option:: NOLATCH

   .. TODO better example
@@ -1302,6 +1527,17 @@ List Of Warnings
   * The variable is tristate or bidirectional. (e.g., :code:`inout`).


+.. option:: STATICVAR
+
+   Warns that a static variable declared in a loop with declaration assignment
+   was converted to automatic. Often such variables were intended to
+   instead be declared "automatic".
+
+   Ignoring this warning may make Verilator differ from other simulators,
+   which will treat the variable as static. Verilator may in future versions also
+   treat the variable as static.
+
+
 .. option:: STMTDLY

   Warns that the code has a statement with a delayed time in front of it.
@@ -1754,11 +1990,15 @@ List Of Warnings

   .. code-block:: sv

-         wait(0);  // Blocks forever
+         wait(1);  // Blocks forever

   Warns that a `wait` statement awaits a constant condition, which means it
   either blocks forever or never blocks.

+   As a special case `wait(0)` with the literal constant `0` (as opposed to
+   something that elaborates to zero), does not warn, as it is presumed the
+   code is making the intent clear.
+

 .. option:: WIDTH

@@ -1813,7 +2053,7 @@ List Of Warnings

 .. option:: WIDTHXZEXPAND

-   A more granular WIDTH warning, for when a value is xz expanded
+   A more granular WIDTH warning, for when a value is X/Z expanded

 .. option:: WIDTHCONCAT

@@ -628,21 +628,32 @@ coroutines ``co_await`` its ``join`` function, and forked ones call ``done``
 when they're finished. Once the required number of coroutines (set using
 ``setCounter``) finish execution, the forking coroutine is resumed.

-Awaitable Utilities
-~~~~~~~~~~~~~~~~~~~
+``VlForever``
+~~~~~~~~~~~~~

-There are also two small utility awaitable types:
-
-* ``VlNow`` is an awaitable that suspends and immediately resumes coroutines.
-  It is used for forcing a coroutine to be moved onto the heap. See the `Forks`
-  section for more detail.
-* ``VlForever`` is used for blocking a coroutine forever. See the `Timing pass`
-  section for more detail.
+A small utility awaitable type. It allows for blocking a coroutine forever. It
+is currently only used for ``wait`` statements that await a constant false
+condition. See the `Timing Pass` section for more details.

 Timing Pass
 ~~~~~~~~~~~

-The visitor in ``V3Timing.cpp`` transforms each timing control into a ``co_await``.
+There are two visitors in ``V3Timing.cpp``.
+
+The first one, ``TimingSuspendableVisitor``, does not perform any AST
+transformations. It is responsible for marking processes and C++ functions that
+contain timing controls as suspendable. Processes that call suspendable
+functions are also marked as suspendable. Functions that call, are overridden
+by, or override suspendable functions are marked as suspendable as well.
+
+The visitor keeps a dependency graph of functions and processes to handle such
+cases. A function or process is dependent on a function if it calls it. A
+virtual class method is dependent on another class method if it calls it,
+overrides it, or is overriden by it.
+
+The second visitor in ``V3Timing.cpp``, ``TimingControlVisitor``, uses the
+information provided by ``TimingSuspendableVisitor`` and transforms each timing
+control into a ``co_await``.

 * event controls are turned into ``co_await`` on a trigger scheduler's
  ``trigger`` method. The awaited trigger scheduler is the one corresponding to
@@ -674,14 +685,9 @@ Each sub-statement of a ``fork`` is put in an ``AstBegin`` node for easier
 grouping. In a later step, each of these gets transformed into a new, separate
 function. See the `Forks` section for more detail.

-Processes that use awaits are marked as suspendable. Later, during ``V3Sched``,
-they are transformed into coroutines. Functions that use awaits get the return
-type of ``VlCoroutine``. This immediately makes them coroutines. Note that if a
-process calls a function that is a coroutine, the call gets wrapped in an
-await, which means the process itself will be marked as suspendable. A virtual
-function is a coroutine if any of its overriding or overridden functions are
-coroutines. The visitor keeps a dependency graph of functions and processes to
-handle such cases.
+Suspendable functions get the return type of ``VlCoroutine``, which makes them
+coroutines. Later, during ``V3Sched``, suspendable processes are also
+transformed into coroutines.

 Scheduling with timing
 ~~~~~~~~~~~~~~~~~~~~~~
@@ -749,9 +755,7 @@ doesn't suspend the forking process.

 In forked processes, references to local variables are only allowed in
 ``fork..join``, as this is the only case that ensures the lifetime of these
-locals are at least as long as the execution of the forked processes. This is
-where ``VlNow`` is used, to ensure the locals are moved to the heap before they
-are passed by reference to the forked processes.
+locals are at least as long as the execution of the forked processes.


 Multithreaded Mode
@@ -1509,8 +1513,19 @@ debug level 5, with the V3Width.cpp file at level 9.
 --debug
 -------

-When you run with ``--debug``, there are two primary output file types
-placed into the obj_dir, .tree and .dot files.
+When you run with ``--debug``, there are three primary output file types
+placed into the obj_dir, .vpp, .tree and .dot files.
+
+.vpp Output
+-----------
+
+Verilator creates a *{mod_prefix}*\ __inputs\ .vpp file containing all the
+files that were read, filtered by preprocessing. This file can be fed back
+into Verilator, replacing on the command line all of the previous input
+files, to enable simplification of test cases.
+
+Verilator also creates .vpp files for each individual file passed on the
+command line.


 .dot Output
@@ -1807,8 +1822,6 @@ IEEE 1800-2017 6.12 "shortreal"
    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"
-    Little/no tool support, makes it difficult to implement parsers.
 IEEE 1800-2017 20.16 Stochastic analysis
    Little industry use.
 IEEE 1800-2017 20.17 PLA modeling
@@ -2110,7 +2123,7 @@ Or in a hand-written C++ wrapper:
 ::

   #ifdef TEST_VERBOSE
-      cout << "Read a=" << a << endl;
+      std::cout << "Read a=" << a << std::endl;
   #endif

 A filename that should be used to check the output results is given with
@@ -6,6 +6,7 @@ Alexandre
 Ami
 Amir
 Anastasiadis
+Anglin
 Anikin
 Antmicro
 Antonin
@@ -42,6 +43,8 @@ Chandan
 Chitlesh
 Christophe
 Cochrane
+Conda
+Corteggiani
 Cuan
 Cygwin
 DErrico
@@ -53,6 +56,7 @@ Das
 Dcache
 Deadman
 Debacker
+Deepa
 Defparams
 Denio
 Deprecations
@@ -96,6 +100,7 @@ Fredieu
 GTKWave
 Galbi
 Gantt
+Garnal
 Gartner
 Gelinek
 Geoff
@@ -188,6 +193,7 @@ Laurens
 Lavino
 Leber
 Leendert
+Lem
 Lesik
 Liland
 Liu
@@ -207,6 +213,8 @@ Matveyenko
 Maupin
 Mdir
 Mednick
+Menküc
+Michail
 Michiels
 Microsystems
 Milanovic
@@ -223,8 +231,10 @@ Muhlestein
 Multithreaded
 Multithreading
 NOUNOPTFLAT
+NaN
 Nalbantis
 Narayan
+Nassim
 Nauticus
 Newgard
 Nigam
@@ -238,6 +248,7 @@ Olof
 Olofsson
 Oyvind
 PLI
+Palaniappan
 Patricio
 Petr
 Piechotka
@@ -252,6 +263,8 @@ Prateek
 Pre
 Preprocess
 Pretet
+Pretl
+Pringlemeir
 Priyadharshini
 Pullup
 Pulver
@@ -266,6 +279,7 @@ Renga
 Requin
 Rodionov
 Rolfe
+Rontionov
 Roodselaar
 Runtime
 Ruud
@@ -295,6 +309,7 @@ Solomatnikov
 Solt
 Southwell
 Srini
+Srinivasan
 Stamness
 Stephane
 Stoddard
@@ -319,6 +334,7 @@ Thiede
 Thierry
 Thyer
 Tichelaar
+Timi
 Tomov
 Tood
 Topa
@@ -343,6 +359,7 @@ Vdeeptemp
 Vdly
 Vemumtab
 Vemuri
+Venkataramanan
 Veriable
 Verialted
 Verilate
@@ -353,6 +370,7 @@ Verilator
 Verilog
 Vighnesh
 Viktor
+Vilp
 Vm
 Vukobratovic
 Wai
@@ -363,6 +381,7 @@ Wfuture
 Whatson
 Wildman
 Wim
+Wmisleading
 Wno
 Wojciech
 Wolfel
@@ -376,6 +395,7 @@ Xuan
 Xuanqi
 Yazdanbakhsh
 Yi
+Yike
 Yinan
 Yosys
 Yu
@@ -396,7 +416,9 @@ architected
 args
 arrarys
 assertOn
+astgen
 async
+atClone
 ato
 atoi
 autoconf
@@ -452,12 +474,14 @@ commandArgsPlusMatch
 compilable
 concat
 concats
+conf
 config
 const
 constexpr
 constpool
 coredump
 coroutine
+coroutines
 countbits
 countones
 cout
@@ -512,6 +536,7 @@ dumpportson
 dumpvars
 dut
 dx
+dynarray
 elab
 elike
 elsif
@@ -520,6 +545,7 @@ endcelldefine
 endfunction
 endgenerate
 endian
+endianness
 endif
 endmodule
 endprotect
@@ -541,6 +567,7 @@ exe
 executables
 expr
 extern
+ezchi
 fanin
 fasttrace
 fauto
@@ -585,6 +612,7 @@ genvar
 genvars
 getenv
 getline
+ggdb
 gmake
 gmon
 gotFinish
@@ -629,12 +657,14 @@ ish
 isunbounded
 isunknown
 jobserver
+jwoutersymatra
 killua
 lang
 lcov
 ld
 leavinel
 len
+libc
 libext
 libgoogle
 libsystemc
@@ -653,7 +683,9 @@ logicals
 longint
 lossy
 lsb
+lubc
 lvalue
+lvalues
 lxt
 macromodule
 makefile
@@ -678,12 +710,15 @@ mtasks
 mulithreaded
 mult
 multidim
+multidriven
 multiinterfaces
 multiline
 multipling
+multipoint
 multithread
 multithreaded
 multithreading
+musl
 mutexes
 mux
 myftptoyman
@@ -714,6 +749,7 @@ ortegon
 oversubscription
 parallelized
 param
+parameterization
 parameterized
 params
 parens
@@ -741,6 +777,7 @@ pragmas
 pre
 precisions
 predefines
+prepareClone
 prepend
 prepended
 preprocess
@@ -762,10 +799,12 @@ pulldowns
 pullup
 pvalue
 pwd
+py
 qrq
 radix
 randc
 randcase
+randstate
 rarr
 rdtsc
 reStructuredText
@@ -807,6 +846,7 @@ specparam
 splitme
 spp
 sqrt
+srandom
 src
 srcdir
 srcfile
@@ -838,6 +878,7 @@ svdpi
 swrite
 sys
 systemc
+tenghtt
 testbench
 threadsafe
 threashold
@@ -869,10 +910,12 @@ typedefs
 typename
 uint
 un
+unbased
 undef
 undefineall
 undriven
 ungetc
+unhandled
 uniquified
 unistd
 unlink
@@ -893,7 +936,9 @@ vc
 vcd
 vcddiff
 vcoverage
+vdhotre
 vec
+ventana
 ver
 verFiles
 verible
@@ -909,6 +954,7 @@ vlt
 vltstd
 vluint
 vpi
+vpiDefName
 vpiLeftRange
 vpiModule
 vpiSize
@@ -938,4 +984,3 @@ ypq
 yurivict
 zdave
 Øyvind
-
@@ -7,7 +7,7 @@
 //======================================================================

 // SystemC global header
-#include <systemc.h>
+#include <systemc>

 // Include common routines
 #include <verilated.h>
@@ -15,6 +15,8 @@
 // Include model header, generated from Verilating "top.v"
 #include "Vtop.h"

+using namespace sc_core;
+
 int sc_main(int argc, char* argv[]) {
    // See a similar example walkthrough in the verilator manpage.

@@ -10,7 +10,7 @@
 #include <memory>

 // SystemC global header
-#include <systemc.h>
+#include <systemc>

 // Include common routines
 #include <verilated.h>
@@ -23,6 +23,8 @@
 // Include model header, generated from Verilating "top.v"
 #include "Vtop.h"

+using namespace sc_core;
+
 int sc_main(int argc, char* argv[]) {
    // This is a more complicated example, please also see the simpler examples/make_hello_c.

@@ -58,6 +58,7 @@
 #endif

 #ifdef __MINGW32__
+#define WIN32_LEAN_AND_MEAN
 #include <windows.h>
 #endif

@@ -131,7 +132,7 @@ void **JenkinsIns(void *base_i, const unsigned char *mem, uint32_t length, uint3
 #define FST_GZIO_LEN                    (32768)
 #define FST_HDR_FOURPACK_DUO_SIZE       (4*1024*1024)

-#if defined(__i386__) || defined(__x86_64__) || defined(_AIX)
+#if defined(__i386__) || defined(__x86_64__) || defined(_AIX) || defined(__aarch64__)
 #define FST_DO_MISALIGNED_OPS
 #endif

@@ -334,26 +335,22 @@ return(NULL);
 /*
 * mmap compatibility
 */
-#if defined __CYGWIN__ || defined __MINGW32__
+#if defined __MINGW32__
 #include <limits.h>
 #define fstMmap(__addr,__len,__prot,__flags,__fd,__off) fstMmap2((__len), (__fd), (__off))
-#define fstMunmap(__addr,__len)                         free(__addr)
+#define fstMunmap(__addr,__len)                         UnmapViewOfFile((LPCVOID)__addr)

 static void *fstMmap2(size_t __len, int __fd, fst_off_t __off)
 {
-(void)__off;
+HANDLE handle = CreateFileMapping((HANDLE)_get_osfhandle(__fd), NULL,
+				  PAGE_READWRITE, (DWORD)(__len >> 32),
+				  (DWORD)__len, NULL);
+if (!handle) { return NULL; }

-unsigned char *pnt = (unsigned char *)malloc(__len);
-fst_off_t cur_offs = lseek(__fd, 0, SEEK_CUR);
-size_t i;
-
-lseek(__fd, 0, SEEK_SET);
-for(i=0;i<__len;i+=SSIZE_MAX)
-        {
-        read(__fd, pnt + i, ((__len - i) >= SSIZE_MAX) ? SSIZE_MAX : (__len - i));
-        }
-lseek(__fd, cur_offs, SEEK_SET);
-return(pnt);
+void *ptr = MapViewOfFileEx(handle, FILE_MAP_READ | FILE_MAP_WRITE,
+			    0, (DWORD)__off, (SIZE_T)__len, (LPVOID)NULL);
+CloseHandle(handle);
+return ptr;
 }
 #else
 #include <sys/mman.h>
@@ -984,14 +981,26 @@ fflush(xc->handle);
 */
 static void fstWriterMmapSanity(void *pnt, const char *file, int line, const char *usage)
 {
-#if !defined(__CYGWIN__) && !defined(__MINGW32__)
-if(pnt == MAP_FAILED)
+if(pnt == NULL
+#ifdef MAP_FAILED
+   || pnt == MAP_FAILED
+#endif
+  )
 	{
 	fprintf(stderr, "fstMmap() assigned to %s failed: errno: %d, file %s, line %d.\n", usage, errno, file, line);
+#if !defined(__MINGW32__)
 	perror("Why");
+#else
+	LPSTR mbuf = NULL;
+	FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM
+		      | FORMAT_MESSAGE_IGNORE_INSERTS, NULL, GetLastError(),
+		      MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+		      (LPSTR)&mbuf, 0, NULL);
+	fprintf(stderr, "%s", mbuf);
+	LocalFree(mbuf);
+#endif
 	pnt = NULL;
 	}
-#endif
 }


@@ -1037,34 +1046,11 @@ if(!xc->curval_mem)

 static void fstDestroyMmaps(struct fstWriterContext *xc, int is_closing)
 {
-#if !defined __CYGWIN__ && !defined __MINGW32__
 (void)is_closing;
-#endif

 fstMunmap(xc->valpos_mem, xc->maxhandle * 4 * sizeof(uint32_t));
 xc->valpos_mem = NULL;

-#if defined __CYGWIN__ || defined __MINGW32__
-if(xc->curval_mem)
-        {
-        if(!is_closing) /* need to flush out for next emulated mmap() read */
-                {
-                unsigned char *pnt = xc->curval_mem;
-                int __fd = fileno(xc->curval_handle);
-                fst_off_t cur_offs = lseek(__fd, 0, SEEK_CUR);
-                size_t i;
-                size_t __len = xc->maxvalpos;
-
-                lseek(__fd, 0, SEEK_SET);
-                for(i=0;i<__len;i+=SSIZE_MAX)
-                        {
-                        write(__fd, pnt + i, ((__len - i) >= SSIZE_MAX) ? SSIZE_MAX : (__len - i));
-                        }
-                lseek(__fd, cur_offs, SEEK_SET);
-                }
-        }
-#endif
-
 fstMunmap(xc->curval_mem, xc->maxvalpos);
 xc->curval_mem = NULL;
 }
@@ -2066,7 +2052,8 @@ if(xc && !xc->already_in_close && !xc->already_in_flush)
                int zfd;
                int fourpack_duo = 0;
 #ifndef __MINGW32__
-                char *fnam = (char *)malloc(strlen(xc->filename) + 5 + 1);
+		int fnam_len = strlen(xc->filename) + 5 + 1;
+                char *fnam = (char *)malloc(fnam_len);
 #endif

                fixup_offs = ftello(xc->handle);
@@ -2156,7 +2143,7 @@ if(xc && !xc->already_in_close && !xc->already_in_flush)
                fflush(xc->handle);

 #ifndef __MINGW32__
-                sprintf(fnam, "%s.hier", xc->filename);
+                snprintf(fnam, fnam_len, "%s.hier", xc->filename);
                unlink(fnam);
                free(fnam);
 #endif
@@ -2835,7 +2822,7 @@ if(ctx && name && literal_arr && val_arr && (elem_count != 0))
 	uint32_t i;

 	name_len = strlen(name);
-	elem_count_len = sprintf(elem_count_buf, "%" PRIu32, elem_count);
+	elem_count_len = snprintf(elem_count_buf, 16, "%" PRIu32, elem_count);

 	literal_lens = (unsigned int *)calloc(elem_count, sizeof(unsigned int));
 	val_lens = (unsigned int *)calloc(elem_count, sizeof(unsigned int));
@@ -3412,6 +3399,7 @@ int flat_hier_alloc_len;
 unsigned do_rewind : 1;
 char str_scope_nam[FST_ID_NAM_SIZ+1];
 char str_scope_comp[FST_ID_NAM_SIZ+1];
+char *str_scope_attr;

 unsigned fseek_failed : 1;

@@ -3922,7 +3910,8 @@ int pass_status = 1;
 if(!xc->fh)
        {
        fst_off_t offs_cache = ftello(xc->f);
-        char *fnam = (char *)malloc(strlen(xc->filename) + 6 + 16 + 32 + 1);
+	int fnam_len = strlen(xc->filename) + 6 + 16 + 32 + 1;
+        char *fnam = (char *)malloc(fnam_len);
        unsigned char *mem = (unsigned char *)malloc(FST_GZIO_LEN);
        fst_off_t hl, uclen;
        fst_off_t clen = 0;
@@ -3941,7 +3930,7 @@ if(!xc->fh)
                htyp = xc->contains_hier_section_lz4duo ? FST_BL_HIER_LZ4DUO : FST_BL_HIER_LZ4;
                }

-        sprintf(fnam, "%s.hier_%d_%p", xc->filename, getpid(), (void *)xc);
+        snprintf(fnam, fnam_len, "%s.hier_%d_%p", xc->filename, getpid(), (void *)xc);
        fstReaderFseeko(xc, xc->f, xc->hier_pos, SEEK_SET);
        uclen = fstReaderUint64(xc->f);
 #ifndef __MINGW32__
@@ -4140,7 +4129,7 @@ if(!(isfeof=feof(xc->fh)))
 			cl = 0;
                        while((ch = fgetc(xc->fh)))
                                {
-				if(cl <= FST_ID_NAM_SIZ)
+				if(cl < FST_ID_NAM_SIZ)
 					{
 					pnt[cl++] = ch;
 					}
@@ -4152,7 +4141,7 @@ if(!(isfeof=feof(xc->fh)))
 			cl = 0;
                        while((ch = fgetc(xc->fh)))
                                {
-				if(cl <= FST_ID_NAM_SIZ)
+				if(cl < FST_ID_NAM_SIZ)
 					{
 					pnt[cl++] = ch;
 					}
@@ -4169,15 +4158,19 @@ if(!(isfeof=feof(xc->fh)))
                        xc->hier.htyp = FST_HT_ATTRBEGIN;
                        xc->hier.u.attr.typ = fgetc(xc->fh);
                        xc->hier.u.attr.subtype = fgetc(xc->fh);
-                        xc->hier.u.attr.name = pnt = xc->str_scope_nam;
+			if(!xc->str_scope_attr)
+				{
+				xc->str_scope_attr = (char *)calloc(1, FST_ID_NAM_ATTR_SIZ+1);
+				}
+                        xc->hier.u.attr.name = pnt = xc->str_scope_attr;
 			cl = 0;
                        while((ch = fgetc(xc->fh)))
                                {
-				if(cl <= FST_ID_NAM_SIZ)
+				if(cl < FST_ID_NAM_ATTR_SIZ)
 					{
 					pnt[cl++] = ch;
 					}
-                                }; /* scopename */
+                                }; /* attrname */
 			pnt[cl] = 0;
                        xc->hier.u.attr.name_length = cl;

@@ -4188,7 +4181,7 @@ if(!(isfeof=feof(xc->fh)))
                                if((xc->hier.u.attr.subtype == FST_MT_SOURCESTEM)||(xc->hier.u.attr.subtype == FST_MT_SOURCEISTEM))
                                        {
                                        int sidx_skiplen_dummy = 0;
-                                        xc->hier.u.attr.arg_from_name = fstGetVarint64((unsigned char *)xc->str_scope_nam, &sidx_skiplen_dummy);
+                                        xc->hier.u.attr.arg_from_name = fstGetVarint64((unsigned char *)xc->str_scope_attr, &sidx_skiplen_dummy);
                                        }
                                }
                        break;
@@ -4237,7 +4230,7 @@ if(!(isfeof=feof(xc->fh)))
 			cl = 0;
                        while((ch = fgetc(xc->fh)))
                                {
-				if(cl <= FST_ID_NAM_SIZ)
+				if(cl < FST_ID_NAM_SIZ)
 					{
 					pnt[cl++] = ch;
 					}
@@ -4376,7 +4369,7 @@ while(!feof(xc->fh))
 			cl = 0;
                        while((ch = fgetc(xc->fh)))
                                {
-				if(cl <= FST_ID_NAM_ATTR_SIZ)
+				if(cl < FST_ID_NAM_ATTR_SIZ)
 					{
 					pnt[cl++] = ch;
 					}
@@ -4398,7 +4391,7 @@ while(!feof(xc->fh))
 			cl = 0;
                        while((ch = fgetc(xc->fh)))
                                {
-				if(cl <= FST_ID_NAM_ATTR_SIZ)
+				if(cl < FST_ID_NAM_ATTR_SIZ)
 					{
 					pnt[cl++] = ch;
 					}
@@ -4487,7 +4480,7 @@ while(!feof(xc->fh))
 			cl = 0;
                        while((ch = fgetc(xc->fh)))
                                {
-				if(cl <= FST_ID_NAM_ATTR_SIZ)
+				if(cl < FST_ID_NAM_ATTR_SIZ)
 					{
 					pnt[cl++] = ch;
 					}
@@ -4594,15 +4587,17 @@ if(sectype == FST_BL_ZWRAPPER)
        int zfd;
        int flen = strlen(xc->filename);
        char *hf;
+	int hf_len;

        seclen = fstReaderUint64(xc->f);
        uclen = fstReaderUint64(xc->f);

        if(!seclen) return(0); /* not finished compressing, this is a failed read */

-        hf = (char *)calloc(1, flen + 16 + 32 + 1);
+	hf_len = flen + 16 + 32 + 1;
+        hf = (char *)calloc(1, hf_len);

-        sprintf(hf, "%s.upk_%d_%p", xc->filename, getpid(), (void *)xc);
+        snprintf(hf, hf_len, "%s.upk_%d_%p", xc->filename, getpid(), (void *)xc);
        fcomp = fopen(hf, "w+b");
        if(!fcomp)
                {
@@ -4974,6 +4969,7 @@ if(xc)
        free(xc->signal_typs); xc->signal_typs = NULL;
        free(xc->signal_lens); xc->signal_lens = NULL;
        free(xc->filename); xc->filename = NULL;
+	free(xc->str_scope_attr); xc->str_scope_attr = NULL;

        if(xc->fh)
                {
@@ -5197,16 +5193,16 @@ for(;;)

                                if(beg_tim)
                                        {
-					if(dumpvars_state == 1) { wx_len = sprintf(wx_buf, "$end\n"); fstWritex(xc, wx_buf, wx_len); dumpvars_state = 2; }
-                                        wx_len = sprintf(wx_buf, "#%" PRIu64 "\n", beg_tim);
+					if(dumpvars_state == 1) { wx_len = snprintf(wx_buf, 32, "$end\n"); fstWritex(xc, wx_buf, wx_len); dumpvars_state = 2; }
+                                        wx_len = snprintf(wx_buf, 32, "#%" PRIu64 "\n", beg_tim);
                                        fstWritex(xc, wx_buf, wx_len);
-					if(!dumpvars_state) { wx_len = sprintf(wx_buf, "$dumpvars\n"); fstWritex(xc, wx_buf, wx_len); dumpvars_state = 1; }
+					if(!dumpvars_state) { wx_len = snprintf(wx_buf, 32, "$dumpvars\n"); fstWritex(xc, wx_buf, wx_len); dumpvars_state = 1; }
                                        }
                                if((xc->num_blackouts)&&(cur_blackout != xc->num_blackouts))
                                        {
                                        if(beg_tim == xc->blackout_times[cur_blackout])
                                                {
-                                                wx_len = sprintf(wx_buf, "$dump%s $end\n", (xc->blackout_activity[cur_blackout++]) ? "on" : "off");
+                                                wx_len = snprintf(wx_buf, 32, "$dump%s $end\n", (xc->blackout_activity[cur_blackout++]) ? "on" : "off");
                                                fstWritex(xc, wx_buf, wx_len);
                                                }
                                        }
@@ -5340,7 +5336,7 @@ for(;;)
                                                                                        clone_d[j] = srcdata[7-j];
                                                                                        }
                                                                                }
-                                                                        sprintf((char *)xc->temp_signal_value_buf, "%.16g", d);
+                                                                        snprintf((char *)xc->temp_signal_value_buf, xc->longest_signal_value_len + 1, "%.16g", d);
                                                                        value_change_callback(user_callback_data_pointer, beg_tim, idx+1, xc->temp_signal_value_buf);
                                                                        }
                                                                }
@@ -5368,7 +5364,7 @@ for(;;)
                                                                                }

                                                                        fstVcdID(vcdid_buf, idx+1);
-                                                                        wx_len = sprintf(wx_buf, "r%.16g %s\n", d, vcdid_buf);
+                                                                        wx_len = snprintf(wx_buf, 64, "r%.16g %s\n", d, vcdid_buf);
                                                                        fstWritex(xc, wx_buf, wx_len);
                                                                        }
                                                                }
@@ -5633,16 +5629,16 @@ for(;;)
                                                }
                                        }

-				if(dumpvars_state == 1) { wx_len = sprintf(wx_buf, "$end\n"); fstWritex(xc, wx_buf, wx_len); dumpvars_state = 2; }
-                                wx_len = sprintf(wx_buf, "#%" PRIu64 "\n", time_table[i]);
+				if(dumpvars_state == 1) { wx_len = snprintf(wx_buf, 32, "$end\n"); fstWritex(xc, wx_buf, wx_len); dumpvars_state = 2; }
+                                wx_len = snprintf(wx_buf, 32, "#%" PRIu64 "\n", time_table[i]);
                                fstWritex(xc, wx_buf, wx_len);
-				if(!dumpvars_state) { wx_len = sprintf(wx_buf, "$dumpvars\n"); fstWritex(xc, wx_buf, wx_len); dumpvars_state = 1; }
+				if(!dumpvars_state) { wx_len = snprintf(wx_buf, 32, "$dumpvars\n"); fstWritex(xc, wx_buf, wx_len); dumpvars_state = 1; }

                                if((xc->num_blackouts)&&(cur_blackout != xc->num_blackouts))
                                        {
                                        if(time_table[i] == xc->blackout_times[cur_blackout])
                                                {
-                                                wx_len = sprintf(wx_buf, "$dump%s $end\n", (xc->blackout_activity[cur_blackout++]) ? "on" : "off");
+                                                wx_len = snprintf(wx_buf, 32, "$dump%s $end\n", (xc->blackout_activity[cur_blackout++]) ? "on" : "off");
                                                fstWritex(xc, wx_buf, wx_len);
                                                }
                                        }
@@ -5892,7 +5888,7 @@ for(;;)
                                                                        clone_d[j] = srcdata[7-j];
                                                                        }
                                                                }
-                                                        sprintf((char *)xc->temp_signal_value_buf, "%.16g", d);
+                                                        snprintf((char *)xc->temp_signal_value_buf, xc->longest_signal_value_len + 1, "%.16g", d);
                                                        value_change_callback(user_callback_data_pointer, time_table[i], idx+1, xc->temp_signal_value_buf);
                                                        }
                                                }
@@ -5918,7 +5914,7 @@ for(;;)
                                                                        }
                                                                }

-                                                        wx_len = sprintf(wx_buf, "r%.16g", d);
+                                                        wx_len = snprintf(wx_buf, 32, "r%.16g", d);
                                                        fstWritex(xc, wx_buf, wx_len);
                                                        }
                                                }
@@ -6024,7 +6020,7 @@ if(xc->signal_lens[facidx] == 1)
                                }
                        }

-                sprintf((char *)buf, "%.16g", d);
+                snprintf((char *)buf, 32, "%.16g", d); /* this will write 18 bytes */
                }
        }

@@ -6616,7 +6612,7 @@ if(xc->signal_lens[facidx] == 1)
                                        }
                                }

-                        sprintf(buf, "r%.16g", d);
+                        snprintf(buf, 32, "r%.16g", d); /* this will write 19 bytes */
                        return(buf);
                        }
                }
@@ -232,9 +232,9 @@ std::string _vl_string_vprintf(const char* formatp, va_list ap) VL_MT_SAFE {
    char* const bufp = new char[len + 1];
    VL_VSNPRINTF(bufp, len + 1, formatp, ap);

-    std::string out{bufp, len};  // Not const to allow move optimization
+    std::string result{bufp, len};  // Not const to allow move optimization
    delete[] bufp;
-    return out;
+    return result;
 }

 uint64_t _vl_dbg_sequence_number() VL_MT_SAFE {
@@ -255,30 +255,89 @@ void VL_DBG_MSGF(const char* formatp, ...) VL_MT_SAFE {
    // includes that otherwise would be required in every Verilated module
    va_list ap;
    va_start(ap, formatp);
-    const std::string out = _vl_string_vprintf(formatp, ap);
+    const std::string result = _vl_string_vprintf(formatp, ap);
    va_end(ap);
    // printf("-imm-V{t%d,%" PRId64 "}%s", VL_THREAD_ID(), _vl_dbg_sequence_number(),
-    // out.c_str());
+    // result.c_str());

    // Using VL_PRINTF not VL_PRINTF_MT so that we can call VL_DBG_MSGF
    // from within the guts of the thread execution machinery (and it goes
    // to the screen and not into the queues we're debugging)
-    VL_PRINTF("-V{t%u,%" PRIu64 "}%s", VL_THREAD_ID(), _vl_dbg_sequence_number(), out.c_str());
+    VL_PRINTF("-V{t%u,%" PRIu64 "}%s", VL_THREAD_ID(), _vl_dbg_sequence_number(), result.c_str());
 }

 void VL_PRINTF_MT(const char* formatp, ...) VL_MT_SAFE {
    va_list ap;
    va_start(ap, formatp);
-    const std::string out = _vl_string_vprintf(formatp, ap);
+    const std::string result = _vl_string_vprintf(formatp, ap);
    va_end(ap);
    VerilatedThreadMsgQueue::post(VerilatedMsg{[=]() {  //
-        VL_PRINTF("%s", out.c_str());
+        VL_PRINTF("%s", result.c_str());
    }});
 }

 //===========================================================================
 // Random -- Mostly called at init time, so not inline.

+VlRNG::VlRNG() VL_MT_SAFE {
+    // Starting point for this new class comes from the global RNG
+    VlRNG& fromr = vl_thread_rng();
+    m_state = fromr.m_state;
+    // Advance the *source* so it can later generate a new number
+    // Xoroshiro128+ algorithm
+    fromr.m_state[1] ^= fromr.m_state[0];
+    fromr.m_state[0] = (((fromr.m_state[0] << 55) | (fromr.m_state[0] >> 9)) ^ fromr.m_state[1]
+                        ^ (fromr.m_state[1] << 14));
+    fromr.m_state[1] = (fromr.m_state[1] << 36) | (fromr.m_state[1] >> 28);
+}
+uint64_t VlRNG::rand64() VL_MT_UNSAFE {
+    // Xoroshiro128+ algorithm
+    const uint64_t result = m_state[0] + m_state[1];
+    m_state[1] ^= m_state[0];
+    m_state[0] = (((m_state[0] << 55) | (m_state[0] >> 9)) ^ m_state[1] ^ (m_state[1] << 14));
+    m_state[1] = (m_state[1] << 36) | (m_state[1] >> 28);
+    return result;
+}
+uint64_t VlRNG::vl_thread_rng_rand64() VL_MT_SAFE {
+    VlRNG& fromr = vl_thread_rng();
+    const uint64_t result = fromr.m_state[0] + fromr.m_state[1];
+    fromr.m_state[1] ^= fromr.m_state[0];
+    fromr.m_state[0] = (((fromr.m_state[0] << 55) | (fromr.m_state[0] >> 9)) ^ fromr.m_state[1]
+                        ^ (fromr.m_state[1] << 14));
+    fromr.m_state[1] = (fromr.m_state[1] << 36) | (fromr.m_state[1] >> 28);
+    return result;
+}
+void VlRNG::srandom(uint64_t n) VL_MT_UNSAFE {
+    m_state[0] = n;
+    m_state[1] = m_state[0];
+    // Fix state as algorithm is slow to randomize if many zeros
+    // This causes a loss of ~ 1 bit of seed entropy, no big deal
+    if (VL_COUNTONES_I(m_state[0]) < 10) m_state[0] = ~m_state[0];
+    if (VL_COUNTONES_I(m_state[1]) < 10) m_state[1] = ~m_state[1];
+}
+std::string VlRNG::get_randstate() const VL_MT_UNSAFE {
+    // Though not stated in IEEE, assumption is the string must be printable
+    const char* const stateCharsp = reinterpret_cast<const char*>(&m_state);
+    static_assert(sizeof(m_state) == 16, "");
+    std::string result{"R00112233445566770011223344556677"};
+    for (size_t i = 0; i < sizeof(m_state); ++i) {
+        result[1 + i * 2] = 'a' + ((stateCharsp[i] >> 4) & 15);
+        result[1 + i * 2 + 1] = 'a' + (stateCharsp[i] & 15);
+    }
+    return result;
+}
+void VlRNG::set_randstate(const std::string& state) VL_MT_UNSAFE {
+    if (VL_UNLIKELY((state.length() != 1 + 2 * sizeof(m_state)) || (state[0] != 'R'))) {
+        VL_PRINTF_MT("%%Warning: set_randstate ignored as state string not from get_randstate\n");
+        return;
+    }
+    char* const stateCharsp = reinterpret_cast<char*>(&m_state);
+    for (size_t i = 0; i < sizeof(m_state); ++i) {
+        stateCharsp[i]
+            = (((state[1 + i * 2] - 'a') & 15) << 4) | ((state[1 + i * 2 + 1] - 'a') & 15);
+    }
+}
+
 static uint32_t vl_sys_rand32() VL_MT_SAFE {
    // Return random 32-bits using system library.
    // Used only to construct seed for Verilator's PRNG.
@@ -292,27 +351,23 @@ static uint32_t vl_sys_rand32() VL_MT_SAFE {
 #endif
 }

-uint64_t vl_rand64() VL_MT_SAFE {
-    static thread_local uint64_t t_state[2];
+VlRNG& VlRNG::vl_thread_rng() VL_MT_SAFE {
+    static thread_local VlRNG t_rng{0};
    static 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())) {
        // Set epoch before state, to avoid race case with new seeding
        t_seedEpoch = VerilatedContextImp::randSeedEpoch();
-        t_state[0] = Verilated::threadContextp()->impp()->randSeedDefault64();
-        t_state[1] = t_state[0];
+        // Same as srandom() but here as needs to be VL_MT_SAFE
+        t_rng.m_state[0] = Verilated::threadContextp()->impp()->randSeedDefault64();
+        t_rng.m_state[1] = t_rng.m_state[0];
        // Fix state as algorithm is slow to randomize if many zeros
        // This causes a loss of ~ 1 bit of seed entropy, no big deal
-        if (VL_COUNTONES_I(t_state[0]) < 10) t_state[0] = ~t_state[0];
-        if (VL_COUNTONES_I(t_state[1]) < 10) t_state[1] = ~t_state[1];
+        if (VL_COUNTONES_I(t_rng.m_state[0]) < 10) t_rng.m_state[0] = ~t_rng.m_state[0];
+        if (VL_COUNTONES_I(t_rng.m_state[1]) < 10) t_rng.m_state[1] = ~t_rng.m_state[1];
    }
-    // Xoroshiro128+ algorithm
-    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);
-    return result;
+    return t_rng;
 }

 WDataOutP VL_RANDOM_W(int obits, WDataOutP outwp) VL_MT_SAFE {
@@ -321,6 +376,12 @@ WDataOutP VL_RANDOM_W(int obits, WDataOutP outwp) VL_MT_SAFE {
    return outwp;
 }

+WDataOutP VL_RANDOM_RNG_W(VlRNG& rngr, int obits, WDataOutP outwp) VL_MT_UNSAFE {
+    for (int i = 0; i < VL_WORDS_I(obits); ++i) outwp[i] = rngr.rand64();
+    // Last word is unclean
+    return outwp;
+}
+
 IData VL_RANDOM_SEEDED_II(IData& seedr) VL_MT_SAFE {
    // $random - seed is a new seed to apply, then we return new seed
    Verilated::threadContextp()->randSeed(static_cast<int>(seedr));
@@ -518,12 +579,12 @@ QData VL_POW_QQW(int, int, int rbits, QData lhs, const WDataInP rwp) VL_MT_SAFE
    // Skip check for rhs == 0, as short-circuit doesn't save time
    if (VL_UNLIKELY(lhs == 0)) return 0;
    QData power = lhs;
-    QData out = 1ULL;
+    QData result = 1ULL;
    for (int bit = 0; bit < rbits; ++bit) {
        if (bit > 0) power = power * power;
-        if (VL_BITISSET_W(rwp, bit)) out *= power;
+        if (VL_BITISSET_W(rwp, bit)) result *= power;
    }
-    return out;
+    return result;
 }

 WDataOutP VL_POWSS_WWW(int obits, int, int rbits, WDataOutP owp, const WDataInP lwp,
@@ -645,7 +706,7 @@ std::string VL_DECIMAL_NW(int width, const WDataInP lwp) VL_MT_SAFE {
 }

 template <typename T>
-std::string _vl_vsformat_time(char* tmp, T ld, int timeunit, bool left, size_t width) {
+std::string _vl_vsformat_time(char* tmp, T ld, int timeunit, bool left, size_t width) VL_MT_SAFE {
    const VerilatedContextImp* const ctxImpp = Verilated::threadContextp()->impp();
    const std::string suffix = ctxImpp->timeFormatSuffix();
    const int userUnits = ctxImpp->timeFormatUnits();  // 0..-15
@@ -1312,16 +1373,18 @@ IData _vl_vsscanf(FILE* fp,  // If a fscanf
                    *p = t_tmp;
                } else if (obits <= VL_BYTESIZE) {
                    CData* const p = va_arg(ap, CData*);
-                    *p = owp[0];
+                    *p = VL_CLEAN_II(obits, obits, owp[0]);
                } else if (obits <= VL_SHORTSIZE) {
                    SData* const p = va_arg(ap, SData*);
-                    *p = owp[0];
+                    *p = VL_CLEAN_II(obits, obits, owp[0]);
                } else if (obits <= VL_IDATASIZE) {
                    IData* const p = va_arg(ap, IData*);
-                    *p = owp[0];
+                    *p = VL_CLEAN_II(obits, obits, owp[0]);
                } else if (obits <= VL_QUADSIZE) {
                    QData* const p = va_arg(ap, QData*);
-                    *p = VL_SET_QW(owp);
+                    *p = VL_CLEAN_QQ(obits, obits, VL_SET_QW(owp));
+                } else {
+                    _vl_clean_inplace_w(obits, owp);
                }
            }
            }  // switch
@@ -1651,15 +1714,15 @@ std::string VL_STACKTRACE_N() VL_MT_SAFE {
    // cppcheck-suppress knownConditionTrueFalse
    if (!strings) return "Unable to backtrace\n";

-    std::string out = "Backtrace:\n";
-    for (int j = 0; j < nptrs; j++) out += std::string{strings[j]} + std::string{"\n"};
+    std::string result = "Backtrace:\n";
+    for (int j = 0; j < nptrs; j++) result += std::string{strings[j]} + std::string{"\n"};
    free(strings);
-    return out;
+    return result;
 }

 void VL_STACKTRACE() VL_MT_SAFE {
-    const std::string out = VL_STACKTRACE_N();
-    VL_PRINTF("%s", out.c_str());
+    const std::string result = VL_STACKTRACE_N();
+    VL_PRINTF("%s", result.c_str());
 }

 IData VL_SYSTEM_IQ(QData lhs) VL_MT_SAFE {
@@ -1805,14 +1868,14 @@ std::string VL_TO_STRING_W(int words, const WDataInP obj) {
 }

 std::string VL_TOLOWER_NN(const std::string& ld) VL_PURE {
-    std::string out = ld;
-    for (auto& cr : out) cr = std::tolower(cr);
-    return out;
+    std::string result = ld;
+    for (auto& cr : result) cr = std::tolower(cr);
+    return result;
 }
 std::string VL_TOUPPER_NN(const std::string& ld) VL_PURE {
-    std::string out = ld;
-    for (auto& cr : out) cr = std::toupper(cr);
-    return out;
+    std::string result = ld;
+    for (auto& cr : result) cr = std::toupper(cr);
+    return result;
 }

 std::string VL_CVT_PACK_STR_NW(int lwords, const WDataInP lwp) VL_PURE {
@@ -1833,6 +1896,12 @@ std::string VL_CVT_PACK_STR_NW(int lwords, const WDataInP lwp) VL_PURE {
    return std::string{destout, len};
 }

+std::string VL_CVT_PACK_STR_ND(const VlQueue<std::string>& q) VL_PURE {
+    std::string output;
+    for (const std::string& s : q) output += s;
+    return output;
+}
+
 std::string VL_PUTC_N(const std::string& lhs, IData rhs, CData ths) VL_PURE {
    std::string lstring = lhs;
    const int32_t rhs_s = rhs;  // To signed value
@@ -1871,7 +1940,6 @@ IData VL_ATOI_N(const std::string& str, int base) VL_PURE {
 IData VL_NTOI_I(int obits, const std::string& str) VL_PURE { return VL_NTOI_Q(obits, str); }
 QData VL_NTOI_Q(int obits, const std::string& str) VL_PURE {
    QData out = 0;
-    const size_t procLen = std::min(str.length(), static_cast<size_t>(8));
    const char* const datap = str.data();
    int pos = static_cast<int>(str.length()) - 1;
    int bit = 0;
@@ -2540,6 +2608,14 @@ VerilatedVirtualBase* VerilatedContext::threadPoolp() {
    return m_threadPool.get();
 }

+void VerilatedContext::prepareClone() { delete m_threadPool.release(); }
+
+VerilatedVirtualBase* VerilatedContext::threadPoolpOnClone() {
+    if (VL_UNLIKELY(m_threadPool)) m_threadPool.release();
+    m_threadPool = std::unique_ptr<VlThreadPool>(new VlThreadPool{this, m_threads - 1});
+    return m_threadPool.get();
+}
+
 VerilatedVirtualBase*
 VerilatedContext::enableExecutionProfiler(VerilatedVirtualBase* (*construct)(VerilatedContext&)) {
    if (!m_executionProfiler) m_executionProfiler.reset(construct(*this));
@@ -3166,15 +3242,18 @@ void VerilatedAssertOneThread::fatal_different() VL_MT_SAFE {
 //===========================================================================
 // VlDeleter:: Methods

-void VlDeleter::deleteAll() {
+void VlDeleter::deleteAll() VL_EXCLUDES(m_mutex) VL_EXCLUDES(m_deleteMutex) VL_MT_SAFE {
    while (true) {
-        VerilatedLockGuard lock{m_mutex};
-        if (m_newGarbage.empty()) break;
-        VerilatedLockGuard deleteLock{m_deleteMutex};
-        std::swap(m_newGarbage, m_toDelete);
-        lock.unlock();  // So destructors can enqueue new objects
+        {
+            VerilatedLockGuard lock{m_mutex};
+            if (m_newGarbage.empty()) break;
+            m_deleteMutex.lock();
+            std::swap(m_newGarbage, m_toDelete);
+            // m_mutex is unlocked here, so destructors can enqueue new objects
+        }
        for (VlDeletable* const objp : m_toDelete) delete objp;
        m_toDelete.clear();
+        m_deleteMutex.unlock();
    }
 }

@@ -30,6 +30,13 @@
 #ifndef VERILATOR_VERILATED_H_
 #define VERILATOR_VERILATED_H_
 #define VERILATOR_VERILATED_H_INTERNAL_
+#ifdef VERILATOR_INTERNAL_
+// This file contains definition of VerilationMutex that should
+// only be used by verilated code. Verilator itself should use
+// mutex from V3Mutex.h. Make sure this file isn't included in
+// verilator code.
+#error "verilated.h should only be included in verilated code"
+#endif

 // clang-format off
 #include "verilatedos.h"
@@ -142,6 +149,15 @@ enum VerilatedVarFlags {
    VLVF_DPI_CLAY = (1 << 10)  // DPI compatible C standard layout
 };

+//=============================================================================
+// Utility functions
+
+template <size_t N>
+inline constexpr size_t roundUpToMultipleOf(size_t value) {
+    static_assert((N & (N - 1)) == 0, "'N' must be a power of 2");
+    return (value + N - 1) & ~(N - 1);
+}
+
 //=========================================================================
 // Mutex and threading support

@@ -159,6 +175,7 @@ public:
    /// Construct mutex (without locking it)
    VerilatedMutex() = default;
    ~VerilatedMutex() = default;
+    VL_UNCOPYABLE(VerilatedMutex);
    const VerilatedMutex& operator!() const { return *this; }  // For -fthread_safety
    /// Acquire/lock mutex
    void lock() VL_ACQUIRE() VL_MT_SAFE {
@@ -202,23 +219,10 @@ public:
    /// Construct and hold given mutex lock until destruction or unlock()
    explicit VerilatedLockGuard(VerilatedMutex& mutexr) VL_ACQUIRE(mutexr) VL_MT_SAFE
        : m_mutexr(mutexr) {  // Need () or GCC 4.8 false warning
-        m_mutexr.lock();
+        mutexr.lock();
    }
    /// Destruct and unlock the mutex
    ~VerilatedLockGuard() VL_RELEASE() { m_mutexr.unlock(); }
-    /// Lock the mutex
-    void lock() VL_ACQUIRE() VL_MT_SAFE { m_mutexr.lock(); }
-    /// Unlock the mutex
-    void unlock() VL_RELEASE() VL_MT_SAFE { m_mutexr.unlock(); }
-    /// Acquire/lock mutex and check for stop request.
-    /// It tries to lock the mutex and if it fails, it check if stop request was send.
-    /// It returns after locking mutex.
-    /// This function should be extracted to V3ThreadPool, but due to clang thread-safety
-    /// limitations it needs to be placed here.
-    void lockCheckStopRequest(std::function<void()> checkStopRequestFunction)
-        VL_ACQUIRE() VL_MT_SAFE {
-        m_mutexr.lockCheckStopRequest(checkStopRequestFunction);
-    }
 };

 // Internals: Remember the calling thread at construction time, and make
@@ -564,6 +568,8 @@ public:
    void addModel(VerilatedModel*);

    VerilatedVirtualBase* threadPoolp();
+    void prepareClone();
+    VerilatedVirtualBase* threadPoolpOnClone();
    VerilatedVirtualBase*
    enableExecutionProfiler(VerilatedVirtualBase* (*construct)(VerilatedContext&));

@@ -607,6 +613,7 @@ public:  // But for internal use only
    VerilatedEvalMsgQueue* __Vm_evalMsgQp;
    explicit VerilatedSyms(VerilatedContext* contextp);  // Pass null for default context
    ~VerilatedSyms();
+    VL_UNCOPYABLE(VerilatedSyms);
 };

 //===========================================================================
@@ -945,18 +952,18 @@ void VerilatedContext::timeprecision(int value) VL_MT_SAFE {
        const VerilatedLockGuard lock{m_mutex};
        m_s.m_timeprecision = value;
 #if VM_SC
-        const sc_time sc_res = sc_get_time_resolution();
-        if (sc_res == sc_time(1, SC_SEC)) {
+        const sc_core::sc_time sc_res = sc_core::sc_get_time_resolution();
+        if (sc_res == sc_core::sc_time(1, sc_core::SC_SEC)) {
            sc_prec = 0;
-        } else if (sc_res == sc_time(1, SC_MS)) {
+        } else if (sc_res == sc_core::sc_time(1, sc_core::SC_MS)) {
            sc_prec = 3;
-        } else if (sc_res == sc_time(1, SC_US)) {
+        } else if (sc_res == sc_core::sc_time(1, sc_core::SC_US)) {
            sc_prec = 6;
-        } else if (sc_res == sc_time(1, SC_NS)) {
+        } else if (sc_res == sc_core::sc_time(1, sc_core::SC_NS)) {
            sc_prec = 9;
-        } else if (sc_res == sc_time(1, SC_PS)) {
+        } else if (sc_res == sc_core::sc_time(1, sc_core::SC_PS)) {
            sc_prec = 12;
-        } else if (sc_res == sc_time(1, SC_FS)) {
+        } else if (sc_res == sc_core::sc_time(1, sc_core::SC_FS)) {
            sc_prec = 15;
        }
 #endif
@@ -31,6 +31,8 @@ CFG_CXXFLAGS_NO_UNUSED = @CFG_CXXFLAGS_NO_UNUSED@
 CFG_CXXFLAGS_WEXTRA = @CFG_CXXFLAGS_WEXTRA@
 # Compiler flags that enable coroutine support
 CFG_CXXFLAGS_COROUTINES = @CFG_CXXFLAGS_COROUTINES@
+# Linker flags
+CFG_LDFLAGS_VERILATED = @CFG_LDFLAGS_VERILATED@
 # Linker libraries for multithreading
 CFG_LDLIBS_THREADS = @CFG_LDLIBS_THREADS@

@@ -77,6 +79,8 @@ VPATH += ..
 VPATH += $(VERILATOR_ROOT)/include
 VPATH += $(VERILATOR_ROOT)/include/vltstd

+LDFLAGS  += $(CFG_LDFLAGS_VERILATED)
+
 #OPT = -ggdb -DPRINTINITSTR -DDETECTCHANGE
 #OPT = -ggdb -DPRINTINITSTR
 CPPFLAGS += $(OPT)
@@ -235,14 +239,16 @@ $(VM_PREFIX)__ALL.a: $(VK_OBJS) $(VM_HIER_LIBS)
 ifneq ($(VM_DEFAULT_RULES),0)
 # Anything not in $(VK_SLOW_OBJS) or $(VK_GLOBAL_OBJS), including verilated.o
 # and user files passed on the Verilator command line use this rule.
+# We put OPT_FAST/OPT_SLOW/OPT_GLOBAL before the other flags to
+# allow USER_CPPFLAGS to override them
 %.o: %.cpp
-	$(OBJCACHE) $(CXX) $(CXXFLAGS) $(CPPFLAGS) $(OPT_FAST) -c -o $@ $<
+	$(OBJCACHE) $(CXX) $(OPT_FAST) $(CXXFLAGS) $(CPPFLAGS) -c -o $@ $<

 $(VK_SLOW_OBJS): %.o: %.cpp
-	$(OBJCACHE) $(CXX) $(CXXFLAGS) $(CPPFLAGS) $(OPT_SLOW) -c -o $@ $<
+	$(OBJCACHE) $(CXX) $(OPT_SLOW) $(CXXFLAGS) $(CPPFLAGS) -c -o $@ $<

 $(VK_GLOBAL_OBJS): %.o: %.cpp
-	$(OBJCACHE) $(CXX) $(CXXFLAGS) $(CPPFLAGS) $(OPT_GLOBAL) -c -o $@ $<
+	$(OBJCACHE) $(CXX) $(OPT_GLOBAL) $(CXXFLAGS) $(CPPFLAGS) -c -o $@ $<
 endif

 #Default rule embedded in make:
@@ -208,11 +208,11 @@ private:
        // Forward to . so we have a whole word
        const std::string suffix = *bpost ? std::string{bpost + 1} : "";

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

-        // cout << "\nch pre="<<prefix<<"  s="<<suffix<<"\nch a="<<old<<"\nch b="<<add
-        // <<"\ncho="<<out<<endl;
-        return out;
+        // std::cout << "\nch pre=" << prefix << "  s=" << suffix << "\nch a="
+        // << old << "\nch b=" << add << "\ncho=" << result << std::endl;
+        return result;
    }
    bool itemMatchesString(VerilatedCovImpItem* itemp, const std::string& match)
        VL_REQUIRES(m_mutex) {
@@ -316,7 +316,7 @@ public:
        valps[2] = page_default.c_str();

        // Keys -> strings
-        std::string keys[VerilatedCovConst::MAX_KEYS];
+        std::array<std::string, VerilatedCovConst::MAX_KEYS> keys;
        for (int i = 0; i < VerilatedCovConst::MAX_KEYS; ++i) {
            if (ckeyps[i] && ckeyps[i][0]) keys[i] = ckeyps[i];
        }
@@ -337,7 +337,7 @@ public:
            const std::string key = keys[i];
            if (!keys[i].empty()) {
                const std::string val = valps[i];
-                // cout<<"   "<<__FUNCTION__<<"  "<<key<<" = "<<val<<endl;
+                // std::cout << "   " << __FUNCTION__ << "  " << key << " = " << val << std::endl;
                m_insertp->m_keys[addKeynum] = valueIndex(key);
                m_insertp->m_vals[addKeynum] = valueIndex(val);
                ++addKeynum;
@@ -19,8 +19,8 @@
 ///
 //=============================================================================

-#ifndef VERILATOR_VERILATED_VCD_SC_H_
-#define VERILATOR_VERILATED_VCD_SC_H_
+#ifndef VERILATOR_VERILATED_FST_SC_H_
+#define VERILATOR_VERILATED_FST_SC_H_

 #include "verilatedos.h"

@@ -36,23 +36,23 @@
 /// with the SystemC simulation kernel, just like a SystemC-documented
 /// trace format.

-class VerilatedFstSc final : sc_trace_file, public VerilatedFstC {
+class VerilatedFstSc final : sc_core::sc_trace_file, public VerilatedFstC {
    // CONSTRUCTORS
    VL_UNCOPYABLE(VerilatedFstSc);

 public:
    /// Construct a SC trace object, and register with the SystemC kernel
    VerilatedFstSc() {
-        sc_get_curr_simcontext()->add_trace_file(this);
+        sc_core::sc_get_curr_simcontext()->add_trace_file(this);
        // We want to avoid a depreciated warning, but still be back compatible.
        // Turning off the message just for this still results in an
        // annoying "to turn off" message.
-        const sc_time t1sec{1, SC_SEC};
+        const sc_core::sc_time t1sec{1, sc_core::SC_SEC};
        if (t1sec.to_default_time_units() != 0) {
-            const sc_time tunits{1.0 / t1sec.to_default_time_units(), SC_SEC};
+            const sc_core::sc_time tunits{1.0 / t1sec.to_default_time_units(), sc_core::SC_SEC};
            spTrace()->set_time_unit(tunits.to_string());
        }
-        spTrace()->set_time_resolution(sc_get_time_resolution().to_string());
+        spTrace()->set_time_resolution(sc_core::sc_get_time_resolution().to_string());
    }
    /// Destruct, flush, and close the dump
    ~VerilatedFstSc() override { close(); }
@@ -60,7 +60,7 @@ public:
    // METHODS - for SC kernel
    // Called by SystemC simulate()
    void cycle(bool delta_cycle) override {
-        if (!delta_cycle) this->dump(sc_time_stamp().to_double());
+        if (!delta_cycle) this->dump(sc_core::sc_time_stamp().to_double());
    }

    // Override VerilatedFstC. Must be called after starting simulation.
@@ -79,7 +79,7 @@ private:
    // Cadence Incisive has these as abstract functions so we must create them
    void set_time_unit(int exponent10_seconds) override {}  // deprecated
 #endif
-    void set_time_unit(double v, sc_time_unit tu) override {}  // LCOV_EXCL_LINE
+    void set_time_unit(double v, sc_core::sc_time_unit tu) override {}  // LCOV_EXCL_LINE

    //--------------------------------------------------
    // SystemC 2.1.v1
@@ -96,8 +96,8 @@ private:
    // Formatting matches that of sc_trace.h
    // LCOV_EXCL_START
 #if (SYSTEMC_VERSION >= 20171012)
-    DECL_TRACE_METHOD_A( sc_event )
-    DECL_TRACE_METHOD_A( sc_time )
+    DECL_TRACE_METHOD_A( sc_core::sc_event )
+    DECL_TRACE_METHOD_A( sc_core::sc_time )
 #endif

    DECL_TRACE_METHOD_A( bool )
@@ -152,9 +152,11 @@ extern const char* vl_mc_scan_plusargs(const char* prefixp) VL_MT_SAFE;  // PLIi
 // Base macros

 // Return true if data[bit] set; not 0/1 return, but 0/non-zero return.
+// Arguments must not have side effects
 #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
+// Argument 'bit' must not have side effects
 #define VL_BITRSHIFT_W(data, bit) ((data)[VL_BITWORD_E(bit)] >> VL_BITBIT_E(bit))

 // Create two 32-bit words from quadword
@@ -260,7 +262,7 @@ extern void _vl_debug_print_w(int lbits, WDataInP const iwp) VL_MT_SAFE;
 #if defined(SYSTEMC_VERSION)
 /// Return current simulation time
 // Already defined: extern sc_time sc_time_stamp();
-inline uint64_t vl_time_stamp64() VL_MT_SAFE { return sc_time_stamp().value(); }
+inline uint64_t vl_time_stamp64() VL_MT_SAFE { return sc_core::sc_time_stamp().value(); }
 #else  // Non-SystemC
 # if !defined(VL_TIME_CONTEXT) && !defined(VL_NO_LEGACY)
 #  ifdef VL_TIME_STAMP64
@@ -758,6 +760,7 @@ static inline IData VL_ONEHOT0_W(int words, WDataInP const lwp) VL_PURE {

 static inline IData VL_CLOG2_I(IData lhs) VL_PURE {
    // There are faster algorithms, or fls GCC4 builtins, but rarely used
+    // In C++20 there will be std::bit_width(lhs) - 1
    if (VL_UNLIKELY(!lhs)) return 0;
    --lhs;
    int shifts = 0;
@@ -953,11 +956,19 @@ static inline void VL_NEGATE_INPLACE_W(int words, WDataOutP owp_lwp) VL_MT_SAFE
 // EMIT_RULE: VL_MUL:    oclean=dirty; lclean==clean; rclean==clean;
 // EMIT_RULE: VL_DIV:    oclean=dirty; lclean==clean; rclean==clean;
 // EMIT_RULE: VL_MODDIV: oclean=dirty; lclean==clean; rclean==clean;
-#define VL_DIV_III(lbits, lhs, rhs) (((rhs) == 0) ? 0 : (lhs) / (rhs))
-#define VL_DIV_QQQ(lbits, lhs, rhs) (((rhs) == 0) ? 0 : (lhs) / (rhs))
+static inline IData VL_DIV_III(int lbits, IData lhs, IData rhs) {
+    return (rhs == 0) ? 0 : lhs / rhs;
+}
+static inline QData VL_DIV_QQQ(int lbits, QData lhs, QData rhs) {
+    return (rhs == 0) ? 0 : lhs / rhs;
+}
 #define VL_DIV_WWW(lbits, owp, lwp, rwp) (_vl_moddiv_w(lbits, owp, lwp, rwp, 0))
-#define VL_MODDIV_III(lbits, lhs, rhs) (((rhs) == 0) ? 0 : (lhs) % (rhs))
-#define VL_MODDIV_QQQ(lbits, lhs, rhs) (((rhs) == 0) ? 0 : (lhs) % (rhs))
+static inline IData VL_MODDIV_III(int lbits, IData lhs, IData rhs) {
+    return (rhs == 0) ? 0 : lhs % rhs;
+}
+static inline QData VL_MODDIV_QQQ(int lbits, QData lhs, QData rhs) {
+    return (rhs == 0) ? 0 : lhs % rhs;
+}
 #define VL_MODDIV_WWW(lbits, owp, lwp, rwp) (_vl_moddiv_w(lbits, owp, lwp, rwp, 1))

 static inline WDataOutP VL_ADD_W(int words, WDataOutP owp, WDataInP const lwp,
@@ -1515,6 +1526,28 @@ static inline WDataOutP VL_STREAML_WWI(int lbits, WDataOutP owp, WDataInP const
    return owp;
 }

+template <typename T>
+static inline void VL_ASSIGN_DYN_Q(VlQueue<T>& q, int elem_size, int lbits, QData from) {
+    const int size = (lbits + elem_size - 1) / elem_size;
+    q.renew(size);
+    const QData mask = VL_MASK_Q(elem_size);
+    for (int i = 0; i < size; ++i) q.at(i) = (T)((from >> (i * elem_size)) & mask);
+}
+
+template <typename T>
+static inline IData VL_DYN_TO_I(const VlQueue<T>& q, int elem_size) {
+    IData ret = 0;
+    for (int i = 0; i < q.size(); ++i) ret |= q.at(i) << (i * elem_size);
+    return ret;
+}
+
+template <typename T>
+static inline QData VL_DYN_TO_Q(const VlQueue<T>& q, int elem_size) {
+    QData ret = 0;
+    for (int i = 0; i < q.size(); ++i) ret |= q.at(i) << (i * elem_size);
+    return ret;
+}
+
 // Because concats are common and wide, it's valuable to always have a clean output.
 // Thus we specify inputs must be clean, so we don't need to clean the output.
 // Note the bit shifts are always constants, so the adds in these constify out.
@@ -2185,6 +2218,7 @@ extern IData VL_DIST_UNIFORM(IData& seedr, IData ustart, IData uend) VL_MT_SAFE;
 // Conversion functions

 extern std::string VL_CVT_PACK_STR_NW(int lwords, const WDataInP lwp) VL_PURE;
+extern std::string VL_CVT_PACK_STR_ND(const VlQueue<std::string>& q) VL_PURE;
 inline std::string VL_CVT_PACK_STR_NQ(QData lhs) VL_PURE {
    VlWide<VL_WQ_WORDS_E> lw;
    VL_SET_WQ(lw, lhs);
@@ -2201,10 +2235,10 @@ inline std::string VL_CONCATN_NNN(const std::string& lhs, const std::string& rhs
    return lhs + rhs;
 }
 inline std::string VL_REPLICATEN_NNQ(const std::string& lhs, IData rep) VL_PURE {
-    std::string out;
-    out.reserve(lhs.length() * rep);
-    for (unsigned times = 0; times < rep; ++times) out += lhs;
-    return out;
+    std::string result;
+    result.reserve(lhs.length() * rep);
+    for (unsigned times = 0; times < rep; ++times) result += lhs;
+    return result;
 }
 inline std::string VL_REPLICATEN_NNI(const std::string& lhs, IData rep) VL_PURE {
    return VL_REPLICATEN_NNQ(lhs, rep);
@@ -1,31 +0,0 @@
-// -*- mode: C++; c-file-style: "cc-mode" -*-
-//*************************************************************************
-//
-// Code available from: https://verilator.org
-//
-// Copyright 2010-2023 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 old string and data-type header
-///
-/// This file is deprecated, and provided for backwards compatibility.
-/// Include verilated.h instead.
-///
-//*************************************************************************
-
-#ifndef VERILATOR_VERILATED_HEAVY_H_
-#define VERILATOR_VERILATED_HEAVY_H_
-
-#ifdef VL_NO_LEGACY
-#error "Include <verilated.h> instead of <verilated_heavy.h>"
-#endif
-
-#include "verilated.h"
-
-#endif  // Guard
@@ -148,7 +148,7 @@ public:
 private:
    VL_UNCOPYABLE(VerilatedThreadMsgQueue);
    // METHODS
-    static VerilatedThreadMsgQueue& threadton() {
+    static VerilatedThreadMsgQueue& threadton() VL_MT_SAFE {
        static thread_local VerilatedThreadMsgQueue t_s;
        return t_s;
    }
@@ -29,7 +29,7 @@

 #include "verilatedos.h"

-#include "systemc.h"
+#include <systemc>

 //=============================================================================
 // For \internal use, get a pointer to m_data in the sc_bv_base class,
@@ -37,9 +37,9 @@
 // use cast magic to get at it.  Saves patching get_datap in SystemC.
 #define VL_SC_BV_DATAP(bv) (VlScBvExposer::sp_datap(bv))
 // This class is thread safe (though most of SystemC is not).
-class VlScBvExposer final : public sc_bv_base {
+class VlScBvExposer final : public sc_dt::sc_bv_base {
 public:
-    static const uint32_t* sp_datap(const sc_bv_base& base) VL_MT_SAFE {
+    static const uint32_t* sp_datap(const sc_dt::sc_bv_base& base) VL_MT_SAFE {
        return static_cast<const VlScBvExposer*>(&base)->sp_datatp();
    }
    const uint32_t* sp_datatp() const { return reinterpret_cast<uint32_t*>(m_data); }
@@ -26,93 +26,167 @@
 // verilator lint_off TIMESCALEMOD
 // verilator lint_off UNUSEDSIGNAL
 package std;
-    // The process class is not implemented, but it's predeclared here,
-    // so the linter accepts references to it.
-    typedef class process;
+   class mailbox #(type T);
+      protected int m_bound;
+      protected T m_queue[$];

-    class mailbox #(type T);
-        protected int m_bound;
-        protected T m_queue[$];
+      function new(int bound = 0);
+         m_bound = bound;
+      endfunction

-        function new(int bound = 0);
-            m_bound = bound;
-        endfunction
+      function int num();
+         return m_queue.size();
+      endfunction

-        function int num();
-            return m_queue.size();
-        endfunction
+      task put(T message);
+`ifdef VERILATOR_TIMING
+         if (m_bound != 0)
+            wait (m_queue.size() < m_bound);
+         m_queue.push_back(message);
+`endif
+      endtask

-        task put(T message);
-    `ifdef VERILATOR_TIMING
-            if (m_bound != 0)
-                wait (m_queue.size() < m_bound);
+      function int try_put(T message);
+         if (num() < m_bound) begin
            m_queue.push_back(message);
-    `endif
-        endtask
+            return 1;
+         end
+         return 0;
+      endfunction

-        function int try_put(T message);
-            if (num() < m_bound) begin
-                m_queue.push_back(message);
-                return 1;
-            end
-            return 0;
-        endfunction
+      task get(ref T message);
+`ifdef VERILATOR_TIMING
+         wait (m_queue.size() > 0);
+         message = m_queue.pop_front();
+`endif
+      endtask

-        task get(ref T message);
-    `ifdef VERILATOR_TIMING
-            wait (m_queue.size() > 0);
+      function int try_get(ref T message);
+         if (num() > 0) begin
            message = m_queue.pop_front();
-    `endif
-        endtask
+            return 1;
+         end
+         return 0;
+      endfunction

-        function int try_get(ref T message);
-            if (num() > 0) begin
-                message = m_queue.pop_front();
-                return 1;
-            end
-            return 0;
-        endfunction
+      task peek(ref T message);
+`ifdef VERILATOR_TIMING
+         wait (m_queue.size() > 0);
+         message = m_queue[0];
+`endif
+      endtask

-        task peek(ref T message);
-    `ifdef VERILATOR_TIMING
-            wait (m_queue.size() > 0);
+      function int try_peek(ref T message);
+         if (num() > 0) begin
            message = m_queue[0];
-    `endif
-        endtask
+            return 1;
+         end
+         return 0;
+      endfunction
+   endclass

-        function int try_peek(ref T message);
-            if (num() > 0) begin
-                message = m_queue[0];
-                return 1;
-            end
-            return 0;
-        endfunction
-    endclass
+   class semaphore;
+      protected int m_keyCount;

-    class semaphore;
-        protected int m_keyCount;
+      function new(int keyCount = 0);
+         m_keyCount = keyCount;
+      endfunction

-        function new(int keyCount = 0);
-            m_keyCount = keyCount;
-        endfunction
+      function void put(int keyCount = 1);
+         m_keyCount += keyCount;
+      endfunction

-        function void put(int keyCount = 1);
-            m_keyCount += keyCount;
-        endfunction
+      task get(int keyCount = 1);
+`ifdef VERILATOR_TIMING
+         wait (m_keyCount >= keyCount);
+         m_keyCount -= keyCount;
+`endif
+      endtask

-        task get(int keyCount = 1);
-    `ifdef VERILATOR_TIMING
-            wait (m_keyCount >= keyCount);
+      function int try_get(int keyCount = 1);
+         if (m_keyCount >= keyCount) begin
            m_keyCount -= keyCount;
-    `endif
-        endtask
+            return 1;
+         end
+         return 0;
+      endfunction
+   endclass

-        function int try_get(int keyCount = 1);
-            if (m_keyCount >= keyCount) begin
-                m_keyCount -= keyCount;
-                return 1;
-            end
-            return 0;
-        endfunction
-    endclass
+   class process;
+      typedef enum {
+         FINISHED  = 0,
+         RUNNING   = 1,
+         WAITING   = 2,
+         SUSPENDED = 3,
+         KILLED    = 4
+      } state;
+
+`ifdef VERILATOR_TIMING
+      // Width visitor changes it to VlProcessRef
+      protected chandle m_process;
+`endif
+
+      static function process self();
+         process p = new;
+`ifdef VERILATOR_TIMING
+         $c(p.m_process, " = vlProcess;");
+`endif
+         return p;
+      endfunction
+
+      protected function void set_status(state s);
+`ifdef VERILATOR_TIMING
+         $c(m_process, "->state(", s, ");");
+`endif
+      endfunction
+
+      function state status();
+`ifdef VERILATOR_TIMING
+         return state'($c(m_process, "->state()"));
+`else
+         return RUNNING;
+`endif
+      endfunction
+
+      function void kill();
+         set_status(KILLED);
+      endfunction
+
+      function void suspend();
+         $error("std::process::suspend() not supported");
+      endfunction
+
+      function void resume();
+         set_status(RUNNING);
+      endfunction
+
+      task await();
+`ifdef VERILATOR_TIMING
+         wait (status() == FINISHED || status() == KILLED);
+`endif
+      endtask
+
+      // When really implemented, srandom must operate on the process, but for
+      // now rely on the srandom() that is automatically generated for all
+      // classes.
+      //
+      // function void srandom(int seed);
+      // endfunction
+
+      // The methods below work only if set_randstate is never applied to
+      // a state string created before another such string. Full support
+      // could use VlRNG class to store the state per process in VlProcess
+      // objects.
+      function string get_randstate();
+         string s;
+
+         s.itoa($random);  // Get a random number
+         set_randstate(s);  // Pretend it's the state of RNG
+         return s;
+      endfunction
+
+      function void set_randstate(string s);
+         $urandom(s.atoi());  // Set the seed using a string
+      endfunction
+   endclass
 endpackage
@@ -173,7 +173,7 @@ public:
        VerilatedLockGuard lock{m_mutex};
        while (m_ready.empty()) {
            m_waiting = true;
-            m_cv.wait(lock);
+            m_cv.wait(m_mutex);
        }
        m_waiting = false;
        // As noted above this is inefficient if our ready list is ever
@@ -30,7 +30,16 @@ void VlCoroutineHandle::resume() {
    // main process
    if (VL_LIKELY(m_coro)) {
        VL_DEBUG_IF(VL_DBG_MSGF("             Resuming: "); dump(););
-        m_coro();
+        if (m_process) {  // If process state is managed with std::process
+            if (m_process->state() == VlProcess::KILLED) {
+                m_coro.destroy();
+            } else {
+                m_process->state(VlProcess::RUNNING);
+                m_coro();
+            }
+        } else {
+            m_coro();
+        }
        m_coro = nullptr;
    }
 }
@@ -95,8 +104,9 @@ void VlTriggerScheduler::resume(const char* eventDescription) {
    VL_DEBUG_IF(dump(eventDescription);
                VL_DBG_MSGF("         Resuming processes waiting for %s\n", eventDescription););
 #endif
-    for (auto& susp : m_ready) susp.resume();
-    m_ready.clear();
+    std::swap(m_ready, m_resumeQueue);
+    for (VlCoroutineHandle& coro : m_resumeQueue) coro.resume();
+    m_resumeQueue.clear();
    commit(eventDescription);
 }

@@ -96,33 +96,52 @@ class VlCoroutineHandle final {

    // MEMBERS
    std::coroutine_handle<> m_coro;  // The wrapped coroutine handle
+    VlProcessRef m_process;  // Data of the suspended process, null if not needed
    VlFileLineDebug m_fileline;

 public:
    // CONSTRUCTORS
    // Construct
-    VlCoroutineHandle()
-        : m_coro{nullptr} {}
-    VlCoroutineHandle(std::coroutine_handle<> coro, VlFileLineDebug fileline)
+    // non-explicit:
+    // cppcheck-suppress noExplicitConstructor
+    VlCoroutineHandle(VlProcessRef process)
+        : m_coro{nullptr}
+        , m_process{process} {
+        if (m_process) m_process->state(VlProcess::WAITING);
+    }
+    VlCoroutineHandle(std::coroutine_handle<> coro, VlProcessRef process, VlFileLineDebug fileline)
        : m_coro{coro}
-        , m_fileline{fileline} {}
+        , m_process{process}
+        , m_fileline{fileline} {
+        if (m_process) m_process->state(VlProcess::WAITING);
+    }
    // Move the handle, leaving a nullptr
+    // non-explicit:
+    // cppcheck-suppress noExplicitConstructor
    VlCoroutineHandle(VlCoroutineHandle&& moved)
        : m_coro{std::exchange(moved.m_coro, nullptr)}
+        , m_process{std::exchange(moved.m_process, nullptr)}
        , m_fileline{moved.m_fileline} {}
    // Destroy if the handle isn't null
    ~VlCoroutineHandle() {
        // Usually these coroutines should get resumed; we only need to clean up if we destroy a
        // model with some coroutines suspended
-        if (VL_UNLIKELY(m_coro)) m_coro.destroy();
+        if (VL_UNLIKELY(m_coro)) {
+            m_coro.destroy();
+            if (m_process && m_process->state() != VlProcess::KILLED) {
+                m_process->state(VlProcess::FINISHED);
+            }
+        }
    }
    // METHODS
    // Move the handle, leaving a null handle
    auto& operator=(VlCoroutineHandle&& moved) {
        m_coro = std::exchange(moved.m_coro, nullptr);
+        m_process = std::exchange(moved.m_process, nullptr);
+        m_fileline = moved.m_fileline;
        return *this;
    }
-    // Resume the coroutine if the handle isn't null
+    // Resume the coroutine if the handle isn't null and the process isn't killed
    void resume();
 #ifdef VL_DEBUG
    void dump() const;
@@ -173,21 +192,24 @@ public:
    void dump() const;
 #endif
    // Used by coroutines for co_awaiting a certain simulation time
-    auto delay(uint64_t delay, const char* filename = VL_UNKNOWN, int lineno = 0) {
+    auto delay(uint64_t delay, VlProcessRef process, const char* filename = VL_UNKNOWN,
+               int lineno = 0) {
        struct Awaitable {
+            VlProcessRef process;  // Data of the suspended process, null if not needed
            VlDelayedCoroutineQueue& queue;
            uint64_t delay;
            VlFileLineDebug fileline;

            bool await_ready() const { return false; }  // Always suspend
            void await_suspend(std::coroutine_handle<> coro) {
-                queue.push_back({delay, VlCoroutineHandle{coro, fileline}});
+                queue.push_back({delay, VlCoroutineHandle{coro, process, fileline}});
                // Move last element to the proper place in the max-heap
                std::push_heap(queue.begin(), queue.end());
            }
            void await_resume() const {}
        };
-        return Awaitable{m_queue, m_context.time() + delay, VlFileLineDebug{filename, lineno}};
+        return Awaitable{process, m_queue, m_context.time() + delay,
+                         VlFileLineDebug{filename, lineno}};
    }
 };

@@ -207,6 +229,10 @@ class VlTriggerScheduler final {
                                   // (not resumable)
    VlCoroutineVec m_ready;  // Coroutines that can be resumed (all coros from m_uncommitted are
                             // moved here in commit())
+    VlCoroutineVec m_resumeQueue;  // Coroutines being resumed by resume(); kept as a field to
+                                   // avoid reallocation. Resumed coroutines are moved to
+                                   // m_resumeQueue to allow adding coroutines to m_ready
+                                   // during resume(). Outside of resume() should always be empty.

 public:
    // METHODS
@@ -220,21 +246,23 @@ public:
    void dump(const char* eventDescription) const;
 #endif
    // Used by coroutines for co_awaiting a certain trigger
-    auto trigger(const char* eventDescription = VL_UNKNOWN, const char* filename = VL_UNKNOWN,
-                 int lineno = 0) {
+    auto trigger(bool commit, VlProcessRef process, const char* eventDescription = VL_UNKNOWN,
+                 const char* filename = VL_UNKNOWN, int lineno = 0) {
        VL_DEBUG_IF(VL_DBG_MSGF("         Suspending process waiting for %s at %s:%d\n",
                                eventDescription, filename, lineno););
        struct Awaitable {
            VlCoroutineVec& suspended;  // Coros waiting on trigger
+            VlProcessRef process;  // Data of the suspended process, null if not needed
            VlFileLineDebug fileline;

            bool await_ready() const { return false; }  // Always suspend
            void await_suspend(std::coroutine_handle<> coro) {
-                suspended.emplace_back(coro, fileline);
+                suspended.emplace_back(coro, process, fileline);
            }
            void await_resume() const {}
        };
-        return Awaitable{m_uncommitted, VlFileLineDebug{filename, lineno}};
+        return Awaitable{commit ? m_ready : m_uncommitted, process,
+                         VlFileLineDebug{filename, lineno}};
    }
 };

@@ -267,18 +295,19 @@ class VlDynamicTriggerScheduler final {
                            // with destructive post updates, e.g. named events)

    // METHODS
-    auto awaitable(VlCoroutineVec& queue, const char* filename, int lineno) {
+    auto awaitable(VlProcessRef process, VlCoroutineVec& queue, const char* filename, int lineno) {
        struct Awaitable {
+            VlProcessRef process;  // Data of the suspended process, null if not needed
            VlCoroutineVec& suspended;  // Coros waiting on trigger
            VlFileLineDebug fileline;

            bool await_ready() const { return false; }  // Always suspend
            void await_suspend(std::coroutine_handle<> coro) {
-                suspended.emplace_back(coro, fileline);
+                suspended.emplace_back(coro, process, fileline);
            }
            void await_resume() const {}
        };
-        return Awaitable{queue, VlFileLineDebug{filename, lineno}};
+        return Awaitable{process, queue, VlFileLineDebug{filename, lineno}};
    }

 public:
@@ -292,36 +321,29 @@ public:
    void dump() const;
 #endif
    // Used by coroutines for co_awaiting trigger evaluation
-    auto evaluation(const char* eventDescription, const char* filename, int lineno) {
+    auto evaluation(VlProcessRef process, const char* eventDescription, const char* filename,
+                    int lineno) {
        VL_DEBUG_IF(VL_DBG_MSGF("         Suspending process waiting for %s at %s:%d\n",
                                eventDescription, filename, lineno););
-        return awaitable(m_suspended, filename, lineno);
+        return awaitable(process, m_suspended, filename, lineno);
    }
    // Used by coroutines for co_awaiting the trigger post update step
-    auto postUpdate(const char* eventDescription, const char* filename, int lineno) {
+    auto postUpdate(VlProcessRef process, const char* eventDescription, const char* filename,
+                    int lineno) {
        VL_DEBUG_IF(
            VL_DBG_MSGF("         Process waiting for %s at %s:%d awaiting the post update step\n",
                        eventDescription, filename, lineno););
-        return awaitable(m_post, filename, lineno);
+        return awaitable(process, m_post, filename, lineno);
    }
    // Used by coroutines for co_awaiting the resumption step (in 'act' eval)
-    auto resumption(const char* eventDescription, const char* filename, int lineno) {
+    auto resumption(VlProcessRef process, const char* eventDescription, const char* filename,
+                    int lineno) {
        VL_DEBUG_IF(VL_DBG_MSGF("         Process waiting for %s at %s:%d awaiting resumption\n",
                                eventDescription, filename, lineno););
-        return awaitable(m_triggered, filename, lineno);
+        return awaitable(process, m_triggered, filename, lineno);
    }
 };

-//=============================================================================
-// VlNow is a helper awaitable type that always suspends, and then immediately resumes a coroutine.
-// Allows forcing the move of coroutine locals to the heap.
-
-struct VlNow {
-    bool await_ready() const { return false; }  // Always suspend
-    bool await_suspend(std::coroutine_handle<>) const { return false; }  // Resume immediately
-    void await_resume() const {}
-};
-
 //=============================================================================
 // VlForever is a helper awaitable type for suspending coroutines forever. Used for constant
 // wait statements.
@@ -348,24 +370,27 @@ class VlForkSync final {

 public:
    // Create the join object and set the counter to the specified number
-    void init(size_t count) { m_join.reset(new VlJoin{count, {}}); }
+    void init(size_t count, VlProcessRef process) { m_join.reset(new VlJoin{count, {process}}); }
    // Called whenever any of the forked processes finishes. If the join counter reaches 0, the
    // main process gets resumed
    void done(const char* filename = VL_UNKNOWN, int lineno = 0);
    // Used by coroutines for co_awaiting a join
-    auto join(const char* filename = VL_UNKNOWN, int lineno = 0) {
+    auto join(VlProcessRef process, const char* filename = VL_UNKNOWN, int lineno = 0) {
        assert(m_join);
        VL_DEBUG_IF(
            VL_DBG_MSGF("             Awaiting join of fork at: %s:%d\n", filename, lineno););
        struct Awaitable {
+            VlProcessRef process;  // Data of the suspended process, null if not needed
            const std::shared_ptr<VlJoin> join;  // Join to await on
            VlFileLineDebug fileline;

            bool await_ready() { return join->m_counter == 0; }  // Suspend if join still exists
-            void await_suspend(std::coroutine_handle<> coro) { join->m_susp = {coro, fileline}; }
+            void await_suspend(std::coroutine_handle<> coro) {
+                join->m_susp = {coro, process, fileline};
+            }
            void await_resume() const {}
        };
-        return Awaitable{m_join, VlFileLineDebug{filename, lineno}};
+        return Awaitable{process, m_join, VlFileLineDebug{filename, lineno}};
    }
 };

@@ -75,7 +75,7 @@ public:
    // Get an element from the front of the queue. Blocks if none available
    T get() VL_MT_SAFE_EXCLUDES(m_mutex) {
        VerilatedLockGuard lock{m_mutex};
-        m_cv.wait(lock, [this]() VL_REQUIRES(m_mutex) { return !m_queue.empty(); });
+        m_cv.wait(m_mutex, [this]() VL_REQUIRES(m_mutex) { return !m_queue.empty(); });
        assert(!m_queue.empty());
        T value = m_queue.front();
        m_queue.pop_front();
@@ -447,7 +447,9 @@ public:
        if (VL_UNLIKELY(diff)) fullIData(oldp, newval, bits);
    }
    VL_ATTR_ALWINLINE void chgQData(uint32_t* oldp, QData newval, int bits) {
-        const uint64_t diff = *reinterpret_cast<QData*>(oldp) ^ newval;
+        QData old;
+        std::memcpy(&old, oldp, sizeof(old));
+        const uint64_t diff = old ^ newval;
        if (VL_UNLIKELY(diff)) fullQData(oldp, newval, bits);
    }
    VL_ATTR_ALWINLINE void chgWData(uint32_t* oldp, const WData* newvalp, int bits) {
@@ -460,8 +462,9 @@ public:
    }
    VL_ATTR_ALWINLINE void chgEvent(uint32_t* oldp, VlEvent newval) { fullEvent(oldp, 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);
+        double old;
+        std::memcpy(&old, oldp, sizeof(old));
+        if (VL_UNLIKELY(old != newval)) fullDouble(oldp, newval);
    }
 };

@@ -482,7 +482,7 @@ VL_ATTR_NOINLINE void VerilatedTrace<VL_SUB_T, VL_BUF_T>::ParallelWorkerData::wa
    // 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_cv.wait(m_mutex, [this] { return m_ready.load(std::memory_order_relaxed); });
    m_waiting = false;
 }

@@ -872,7 +872,7 @@ void VerilatedTraceBuffer<VL_BUF_T>::fullIData(uint32_t* oldp, IData newval, int
 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;
+    std::memcpy(oldp, &newval, sizeof(newval));
    if (VL_UNLIKELY(m_sigs_enabledp && !(VL_BITISSET_W(m_sigs_enabledp, code)))) return;
    emitQData(code, newval, bits);
 }
@@ -888,7 +888,7 @@ void VerilatedTraceBuffer<VL_BUF_T>::fullWData(uint32_t* oldp, const WData* newv
 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;
+    std::memcpy(oldp, &newval, sizeof(newval));
    if (VL_UNLIKELY(m_sigs_enabledp && !(VL_BITISSET_W(m_sigs_enabledp, code)))) return;
    // cppcheck-suppress invalidPointerCast
    emitDouble(code, newval);
@@ -73,15 +73,45 @@ extern std::string VL_TO_STRING_W(int words, const WDataInP obj);
 #define VL_OUT(name, msb, lsb) IData name  ///< Declare output signal, 17-32 bits
 #define VL_OUTW(name, msb, lsb, words) VlWide<words> name  ///< Declare output signal, 65+ bits

+//===================================================================
+// VlProcess stores metadata of running processes
+
+class VlProcess final {
+    // MEMBERS
+    int m_state;  // Current state of the process
+
+public:
+    // TYPES
+    enum : int {  // Type int for compatibility with $c
+        FINISHED = 0,
+        RUNNING = 1,
+        WAITING = 2,
+        SUSPENDED = 3,
+        KILLED = 4,
+    };
+
+    // CONSTRUCTORS
+    VlProcess()
+        : m_state{RUNNING} {}
+
+    // METHODS
+    int state() { return m_state; }
+    void state(int s) { m_state = s; }
+};
+
+using VlProcessRef = std::shared_ptr<VlProcess>;
+
+inline std::string VL_TO_STRING(const VlProcessRef& p) { return std::string("process"); }
+
 //===================================================================
 // Activity trigger vector

 template <std::size_t T_size>  //
 class VlTriggerVec final {
    // TODO: static assert T_size > 0, and don't generate when empty
-private:
+
    // MEMBERS
-    std::array<bool, T_size> m_flags;  // State of the assoc array
+    alignas(16) std::array<uint64_t, roundUpToMultipleOf<64>(T_size) / 64> m_flags;  // The flags

 public:
    // CONSTRUCTOR
@@ -91,10 +121,18 @@ public:
    // METHODS

    // Set all elements to false
-    void clear() { m_flags.fill(false); }
+    void clear() { m_flags.fill(0); }

-    // Reference to element at 'index'
-    bool& at(size_t index) { return m_flags.at(index); }
+    // Word at given 'wordIndex'
+    uint64_t word(size_t wordIndex) const { return m_flags[wordIndex]; }
+
+    // Set specified flag to given value
+    void set(size_t index, bool value) {
+        uint64_t& w = m_flags[index / 64];
+        const size_t bitIndex = index % 64;
+        w &= ~(1ULL << bitIndex);
+        w |= (static_cast<uint64_t>(value) << bitIndex);
+    }

    // Return true iff at least one element is set
    bool any() const {
@@ -104,13 +142,13 @@ public:
    }

    // Set all elements true in 'this' that are set in 'other'
-    void set(const VlTriggerVec<T_size>& other) {
+    void thisOr(const VlTriggerVec<T_size>& other) {
        for (size_t i = 0; i < m_flags.size(); ++i) m_flags[i] |= other.m_flags[i];
    }

    // Set elements of 'this' to 'a & !b' element-wise
    void andNot(const VlTriggerVec<T_size>& a, const VlTriggerVec<T_size>& b) {
-        for (size_t i = 0; i < m_flags.size(); ++i) m_flags[i] = a.m_flags[i] && !b.m_flags[i];
+        for (size_t i = 0; i < m_flags.size(); ++i) m_flags[i] = a.m_flags[i] & ~b.m_flags[i];
    }
 };

@@ -136,14 +174,34 @@ public:
 };

 inline std::string VL_TO_STRING(const VlEvent& e) {
-    return std::string("triggered=") + (e.isTriggered() ? "true" : "false");
+    return std::string{"triggered="} + (e.isTriggered() ? "true" : "false");
 }

 //===================================================================
-// Shuffle RNG
+// Random

-extern uint64_t vl_rand64() VL_MT_SAFE;
+// Random Number Generator with internal state
+class VlRNG final {
+    std::array<uint64_t, 2> m_state;

+public:
+    // The default constructor simply sets state, to avoid vl_rand64()
+    // having to check for construction at each call
+    // Alternative: seed with zero and check on rand64() call
+    VlRNG() VL_MT_SAFE;
+    explicit VlRNG(uint64_t seed0) VL_MT_SAFE : m_state{0x12341234UL, seed0} {}
+    void srandom(uint64_t n) VL_MT_UNSAFE;
+    std::string get_randstate() const VL_MT_UNSAFE;
+    void set_randstate(const std::string& state) VL_MT_UNSAFE;
+    uint64_t rand64() VL_MT_UNSAFE;
+    // Threadsafe, but requires use on vl_thread_rng
+    static uint64_t vl_thread_rng_rand64() VL_MT_SAFE;
+    static VlRNG& vl_thread_rng() VL_MT_SAFE;
+};
+
+inline uint64_t vl_rand64() VL_MT_SAFE { return VlRNG::vl_thread_rng_rand64(); }
+
+// RNG for shuffle()
 class VlURNG final {
 public:
    using result_type = size_t;
@@ -152,6 +210,11 @@ public:
    size_t operator()() { return VL_MASK_I(31) & vl_rand64(); }
 };

+// These require the class object to have the thread safety lock
+inline IData VL_RANDOM_RNG_I(VlRNG& rngr) VL_MT_UNSAFE { return rngr.rand64(); }
+inline QData VL_RANDOM_RNG_Q(VlRNG& rngr) VL_MT_UNSAFE { return rngr.rand64(); }
+extern WDataOutP VL_RANDOM_RNG_W(VlRNG& rngr, int obits, WDataOutP outwp) VL_MT_UNSAFE;
+
 //===================================================================
 // Readmem/Writemem operation classes

@@ -370,18 +433,17 @@ public:
    // 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(int32_t index) {
-        static thread_local T_Value s_throwAway;
+        static thread_local T_Value t_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();
-            return s_throwAway;
+            t_throwAway = atDefault();
+            return t_throwAway;
        } else {
            return m_deque[index];
        }
    }
    // Accessing. Verilog: v = assoc[index]
    const T_Value& at(int32_t index) const {
-        static 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();
@@ -389,6 +451,10 @@ public:
            return m_deque[index];
        }
    }
+    // Access with an index counted from end (e.g. q[$])
+    T_Value& atBack(int32_t index) { return at(m_deque.size() - 1 - index); }
+    const T_Value& atBack(int32_t index) const { return at(m_deque.size() - 1 - index); }
+
    // function void q.insert(index, value);
    void insert(int32_t index, const T_Value& value) {
        if (VL_UNLIKELY(index < 0 || index >= m_deque.size())) return;
@@ -404,6 +470,12 @@ public:
        for (int32_t i = lsb; i <= msb; ++i) out.push_back(m_deque[i]);
        return out;
    }
+    VlQueue sliceFrontBack(int32_t lsb, int32_t msb) const {
+        return slice(lsb, m_deque.size() - 1 - msb);
+    }
+    VlQueue sliceBackBack(int32_t lsb, int32_t msb) const {
+        return slice(m_deque.size() - 1 - lsb, m_deque.size() - 1 - msb);
+    }

    // For save/restore
    const_iterator begin() const { return m_deque.begin(); }
@@ -445,7 +517,7 @@ public:
    template <typename Func>
    VlQueue unique(Func with_func) const {
        VlQueue out;
-        std::set<T_Value> saw;
+        std::set<decltype(with_func(0, m_deque[0]))> saw;
        for (const auto& i : m_deque) {
            const auto i_mapped = with_func(0, i);
            const auto it = saw.find(i_mapped);
@@ -474,7 +546,7 @@ public:
    VlQueue<IData> unique_index(Func with_func) const {
        VlQueue<IData> out;
        IData index = 0;
-        std::unordered_set<T_Value> saw;
+        std::set<decltype(with_func(0, m_deque[0]))> saw;
        for (const auto& i : m_deque) {
            const auto i_mapped = with_func(index, i);
            auto it = saw.find(i_mapped);
@@ -788,6 +860,22 @@ public:
        }
        return out;
    }
+    template <typename Func>
+    VlQueue<T_Value> unique(Func with_func) const {
+        VlQueue<T_Value> out;
+        T_Key default_key;
+        using WithType = decltype(with_func(m_map.begin()->first, m_map.begin()->second));
+        std::set<WithType> saw;
+        for (const auto& i : m_map) {
+            const auto i_mapped = with_func(default_key, i.second);
+            const auto it = saw.find(i_mapped);
+            if (it == saw.end()) {
+                saw.insert(it, i_mapped);
+                out.push_back(i.second);
+            }
+        }
+        return out;
+    }
    VlQueue<T_Key> unique_index() const {
        VlQueue<T_Key> out;
        std::set<T_Key> saw;
@@ -801,6 +889,21 @@ public:
        return out;
    }
    template <typename Func>
+    VlQueue<T_Key> unique_index(Func with_func) const {
+        VlQueue<T_Key> out;
+        using WithType = decltype(with_func(m_map.begin()->first, m_map.begin()->second));
+        std::set<WithType> saw;
+        for (const auto& i : m_map) {
+            const auto i_mapped = with_func(i.first, i.second);
+            auto it = saw.find(i_mapped);
+            if (it == saw.end()) {
+                saw.insert(it, i_mapped);
+                out.push_back(i.first);
+            }
+        }
+        return out;
+    }
+    template <typename Func>
    VlQueue<T_Value> find(Func with_func) const {
        VlQueue<T_Value> out;
        for (const auto& i : m_map)
@@ -861,6 +964,16 @@ public:
            });
        return VlQueue<T_Value>::cons(it->second);
    }
+    template <typename Func>
+    VlQueue<T_Value> min(Func with_func) const {
+        if (m_map.empty()) return VlQueue<T_Value>();
+        const auto it = std::min_element(
+            m_map.begin(), m_map.end(),
+            [&with_func](const std::pair<T_Key, T_Value>& a, const std::pair<T_Key, T_Value>& b) {
+                return with_func(a.first, a.second) < with_func(b.first, b.second);
+            });
+        return VlQueue<T_Value>::cons(it->second);
+    }
    VlQueue<T_Value> max() const {
        if (m_map.empty()) return VlQueue<T_Value>();
        const auto it = std::max_element(
@@ -870,6 +983,16 @@ public:
            });
        return VlQueue<T_Value>::cons(it->second);
    }
+    template <typename Func>
+    VlQueue<T_Value> max(Func with_func) const {
+        if (m_map.empty()) return VlQueue<T_Value>();
+        const auto it = std::max_element(
+            m_map.begin(), m_map.end(),
+            [&with_func](const std::pair<T_Key, T_Value>& a, const std::pair<T_Key, T_Value>& b) {
+                return with_func(a.first, a.second) < with_func(b.first, b.second);
+            });
+        return VlQueue<T_Value>::cons(it->second);
+    }

    T_Value r_sum() const {
        T_Value out(0);  // Type must have assignment operator
@@ -998,9 +1121,15 @@ void VL_WRITEMEM_N(bool hex, int bits, const std::string& filename,

 template <class T_Value, std::size_t T_Depth>
 struct VlUnpacked final {
+private:
+    // TYPES
+    using T_Key = IData;  // Index type, for uniformity with other containers
+    using Unpacked = T_Value[T_Depth];
+
+public:
    // 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
+    Unpacked m_storage;  // Contents of the unpacked array

    // CONSTRUCTORS
    // Default constructors and destructor are used. Note however that C++20 requires that
@@ -1011,6 +1140,7 @@ struct VlUnpacked final {
    // Default copy assignment operators are used.

    // METHODS
+public:
    // Raw access
    WData* data() { return &m_storage[0]; }
    const WData* data() const { return &m_storage[0]; }
@@ -1023,6 +1153,170 @@ struct VlUnpacked final {
    bool neq(const VlUnpacked<T_Value, T_Depth>& that) const { return neq(*this, that); }
    // Similar to 'neq' above, *this = that used for change detection
    void assign(const VlUnpacked<T_Value, T_Depth>& that) { *this = that; }
+    bool operator==(const VlUnpacked<T_Value, T_Depth>& that) const { return !neq(that); }
+    bool operator!=(const VlUnpacked<T_Value, T_Depth>& that) { return neq(that); }
+
+    void sort() { std::sort(std::begin(m_storage), std::end(m_storage)); }
+    template <typename Func>
+    void sort(Func with_func) {
+        // with_func returns arbitrary type to use for the sort comparison
+        std::sort(std::begin(m_storage), std::end(m_storage),
+                  [=](const T_Value& a, const T_Value& b) {
+                      // index number is meaningless with sort, as it changes
+                      return with_func(0, a) < with_func(0, b);
+                  });
+    }
+    // std::rbegin/std::rend not available until C++14
+    void rsort() {
+        std::sort(std::begin(m_storage), std::end(m_storage), std::greater<T_Value>());
+    }
+    template <typename Func>
+    void rsort(Func with_func) {
+        // with_func returns arbitrary type to use for the sort comparison
+        // std::rbegin/std::rend not available until C++14, so using > below
+        std::sort(std::begin(m_storage), std::end(m_storage),
+                  [=](const T_Value& a, const T_Value& b) {
+                      // index number is meaningless with sort, as it changes
+                      return with_func(0, a) > with_func(0, b);
+                  });
+    }
+    void reverse() { std::reverse(std::begin(m_storage), std::end(m_storage)); }
+    void shuffle() { std::shuffle(std::begin(m_storage), std::end(m_storage), VlURNG{}); }
+    VlQueue<T_Value> unique() const {
+        VlQueue<T_Value> out;
+        std::set<T_Value> saw;
+        for (const auto& i : m_storage) {
+            const auto it = saw.find(i);
+            if (it == saw.end()) {
+                saw.insert(it, i);
+                out.push_back(i);
+            }
+        }
+        return out;
+    }
+    template <typename Func>
+    VlQueue<T_Value> unique(Func with_func) const {
+        VlQueue<T_Value> out;
+        std::set<T_Value> saw;
+        for (const auto& i : m_storage) {
+            const auto i_mapped = with_func(0, i);
+            const auto it = saw.find(i_mapped);
+            if (it == saw.end()) {
+                saw.insert(it, i_mapped);
+                out.push_back(i);
+            }
+        }
+        return out;
+    }
+    VlQueue<T_Key> unique_index() const {
+        VlQueue<T_Key> out;
+        IData index = 0;
+        std::set<T_Value> saw;
+        for (const auto& i : m_storage) {
+            const auto it = saw.find(i);
+            if (it == saw.end()) {
+                saw.insert(it, i);
+                out.push_back(index);
+            }
+            ++index;
+        }
+        return out;
+    }
+    template <typename Func>
+    VlQueue<T_Key> unique_index(Func with_func) const {
+        VlQueue<T_Key> out;
+        IData index = 0;
+        std::unordered_set<T_Value> saw;
+        for (const auto& i : m_storage) {
+            const auto i_mapped = with_func(index, i);
+            auto it = saw.find(i_mapped);
+            if (it == saw.end()) {
+                saw.insert(it, i_mapped);
+                out.push_back(index);
+            }
+            ++index;
+        }
+        return out;
+    }
+    template <typename Func>
+    VlQueue<T_Value> find(Func with_func) const {
+        VlQueue<T_Value> out;
+        IData index = 0;
+        for (const auto& i : m_storage) {
+            if (with_func(index, i)) out.push_back(i);
+            ++index;
+        }
+        return out;
+    }
+    template <typename Func>
+    VlQueue<T_Key> find_index(Func with_func) const {
+        VlQueue<T_Key> out;
+        IData index = 0;
+        for (const auto& i : m_storage) {
+            if (with_func(index, i)) out.push_back(index);
+            ++index;
+        }
+        return out;
+    }
+    template <typename Func>
+    VlQueue<T_Value> find_first(Func with_func) const {
+        // Can't use std::find_if as need index number
+        IData index = 0;
+        for (const auto& i : m_storage) {
+            if (with_func(index, i)) return VlQueue<T_Value>::cons(i);
+            ++index;
+        }
+        return VlQueue<T_Value>{};
+    }
+    template <typename Func>
+    VlQueue<T_Key> find_first_index(Func with_func) const {
+        IData index = 0;
+        for (const auto& i : m_storage) {
+            if (with_func(index, i)) return VlQueue<IData>::cons(index);
+            ++index;
+        }
+        return VlQueue<T_Key>{};
+    }
+    template <typename Func>
+    VlQueue<T_Value> find_last(Func with_func) const {
+        for (int i = T_Depth - 1; i >= 0; i--) {
+            if (with_func(i, m_storage[i])) return VlQueue<T_Value>::cons(m_storage[i]);
+        }
+        return VlQueue<T_Value>{};
+    }
+    template <typename Func>
+    VlQueue<T_Key> find_last_index(Func with_func) const {
+        for (int i = T_Depth - 1; i >= 0; i--) {
+            if (with_func(i, m_storage[i])) return VlQueue<IData>::cons(i);
+        }
+        return VlQueue<T_Key>{};
+    }
+
+    // Reduction operators
+    VlQueue<T_Value> min() const {
+        const auto it = std::min_element(std::begin(m_storage), std::end(m_storage));
+        return VlQueue<T_Value>::cons(*it);
+    }
+    template <typename Func>
+    VlQueue<T_Value> min(Func with_func) const {
+        const auto it = std::min_element(std::begin(m_storage), std::end(m_storage),
+                                         [&with_func](const IData& a, const IData& b) {
+                                             return with_func(0, a) < with_func(0, b);
+                                         });
+        return VlQueue<T_Value>::cons(*it);
+    }
+    VlQueue<T_Value> max() const {
+        const auto it = std::max_element(std::begin(m_storage), std::end(m_storage));
+        return VlQueue<T_Value>::cons(*it);
+    }
+    template <typename Func>
+    VlQueue<T_Value> max(Func with_func) const {
+        const auto it = std::max_element(std::begin(m_storage), std::end(m_storage),
+                                         [&with_func](const IData& a, const IData& b) {
+                                             return with_func(0, a) < with_func(0, b);
+                                         });
+        return VlQueue<T_Value>::cons(*it);
+    }

    // Dumping. Verilog: str = $sformatf("%p", assoc)
    std::string to_string() const {
@@ -1096,7 +1390,7 @@ public:
    }

    // Deletes all queued garbage objects.
-    void deleteAll() VL_MT_SAFE;
+    void deleteAll() VL_EXCLUDES(m_mutex) VL_EXCLUDES(m_deleteMutex) VL_MT_SAFE;
 };

 //===================================================================
@@ -1166,7 +1460,8 @@ public:
    // CONSTRUCTORS
    VlClassRef() = default;
    // Init with nullptr
-    explicit VlClassRef(VlNull){};
+    // cppcheck-suppress noExplicitConstructor
+    VlClassRef(VlNull){};
    template <typename... T_Args>
    VlClassRef(VlDeleter& deleter, T_Args&&... args)
        // () required here to avoid narrowing conversion warnings,
@@ -1188,6 +1483,16 @@ public:
    // cppcheck-suppress noExplicitConstructor
    VlClassRef(VlClassRef&& moved)
        : m_objp{vlstd::exchange(moved.m_objp, nullptr)} {}
+    // cppcheck-suppress noExplicitConstructor
+    template <typename T_OtherClass>
+    VlClassRef(const VlClassRef<T_OtherClass>& copied)
+        : m_objp{copied.m_objp} {
+        refCountInc();
+    }
+    // cppcheck-suppress noExplicitConstructor
+    template <typename T_OtherClass>
+    VlClassRef(VlClassRef<T_OtherClass>&& moved)
+        : m_objp{vlstd::exchange(moved.m_objp, nullptr)} {}
    ~VlClassRef() { refCountDec(); }

    // METHODS
@@ -1233,8 +1538,14 @@ public:
    // For 'if (ptr)...'
    operator bool() const { return m_objp; }
    // In SV A == B iff both are handles to the same object (IEEE 1800-2017 8.4)
-    bool operator==(const VlClassRef& rhs) const { return m_objp == rhs.m_objp; };
-    bool operator!=(const VlClassRef& rhs) const { return m_objp != rhs.m_objp; };
+    template <typename T_OtherClass>
+    bool operator==(const VlClassRef<T_OtherClass>& rhs) const {
+        return m_objp == rhs.m_objp;
+    };
+    template <typename T_OtherClass>
+    bool operator!=(const VlClassRef<T_OtherClass>& rhs) const {
+        return m_objp != rhs.m_objp;
+    };
 };

 template <typename T, typename U>
@@ -61,16 +61,6 @@ 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

@@ -420,28 +410,14 @@ void VerilatedVcd::dumpHeader() {
            if (*np == ' ') np++;
            if (*np == '\t') break;  // tab means signal name starts
            printIndent(1);
-            // Find character after name end
-            const char* sp = np;
-            while (*sp && *sp != ' ' && *sp != '\t' && !(*sp & '\x80')) sp++;
-
-            printStr("$scope ");
-            if (*sp & '\x80') {
-                switch (*sp & 0x7f) {
-                case VLT_TRACE_SCOPE_STRUCT: printStr("struct "); break;
-                case VLT_TRACE_SCOPE_INTERFACE: printStr("interface "); break;
-                case VLT_TRACE_SCOPE_UNION: printStr("union "); break;
-                default: printStr("module ");
-                }
-            } else {
-                printStr("module ");
-            }
+            printStr("$scope module ");

            for (; *np && *np != ' ' && *np != '\t'; np++) {
                if (*np == '[') {
                    printStr("[");
                } else if (*np == ']') {
                    printStr("]");
-                } else if (!(*np & '\x80')) {
+                } else {
                    *m_writep++ = *np;
                }
            }
@@ -36,23 +36,23 @@
 /// with the SystemC simulation kernel, just like a SystemC-documented
 /// trace format.

-class VerilatedVcdSc final : sc_trace_file, public VerilatedVcdC {
+class VerilatedVcdSc final : sc_core::sc_trace_file, public VerilatedVcdC {
    // CONSTRUCTORS
    VL_UNCOPYABLE(VerilatedVcdSc);

 public:
    /// Construct a SC trace object, and register with the SystemC kernel
    VerilatedVcdSc() {
-        sc_get_curr_simcontext()->add_trace_file(this);
+        sc_core::sc_get_curr_simcontext()->add_trace_file(this);
        // We want to avoid a depreciated warning, but still be back compatible.
        // Turning off the message just for this still results in an
        // annoying "to turn off" message.
-        const sc_time t1sec{1, SC_SEC};
+        const sc_core::sc_time t1sec{1, sc_core::SC_SEC};
        if (t1sec.to_default_time_units() != 0) {
-            const sc_time tunits{1.0 / t1sec.to_default_time_units(), SC_SEC};
+            const sc_core::sc_time tunits{1.0 / t1sec.to_default_time_units(), sc_core::SC_SEC};
            spTrace()->set_time_unit(tunits.to_string());
        }
-        spTrace()->set_time_resolution(sc_get_time_resolution().to_string());
+        spTrace()->set_time_resolution(sc_core::sc_get_time_resolution().to_string());
    }
    /// Destruct, flush, and close the dump
    ~VerilatedVcdSc() override { close(); }
@@ -60,7 +60,7 @@ public:
    // METHODS - for SC kernel
    // Called by SystemC simulate()
    void cycle(bool delta_cycle) override {
-        if (!delta_cycle) this->dump(sc_time_stamp().to_double());
+        if (!delta_cycle) this->dump(sc_core::sc_time_stamp().to_double());
    }

    // Override VerilatedVcdC. Must be called after starting simulation.
@@ -78,7 +78,7 @@ private:
    // Cadence Incisive has these as abstract functions so we must create them
    void set_time_unit(int exponent10_seconds) override {}  // deprecated
 #endif
-    void set_time_unit(double v, sc_time_unit tu) override {}  // LCOV_EXCL_LINE
+    void set_time_unit(double v, sc_core::sc_time_unit tu) override {}  // LCOV_EXCL_LINE

    //--------------------------------------------------
    // SystemC 2.1.v1
@@ -95,8 +95,8 @@ private:
    // Formatting matches that of sc_trace.h
    // LCOV_EXCL_START
 #if (SYSTEMC_VERSION >= 20171012)
-    DECL_TRACE_METHOD_A( sc_event )
-    DECL_TRACE_METHOD_A( sc_time )
+    DECL_TRACE_METHOD_A( sc_core::sc_event )
+    DECL_TRACE_METHOD_A( sc_core::sc_time )
 #endif

    DECL_TRACE_METHOD_A( bool )
@@ -165,6 +165,7 @@ class VerilatedVpioVarBase VL_NOT_FINAL : public VerilatedVpio {
 protected:
    const VerilatedVar* m_varp = nullptr;
    const VerilatedScope* m_scopep = nullptr;
+    std::string m_fullname;
    const VerilatedRange& get_range() const {
        // Determine number of dimensions and return outermost
        return (m_varp->dims() > 1) ? m_varp->unpacked() : m_varp->packed();
@@ -173,11 +174,13 @@ protected:
 public:
    VerilatedVpioVarBase(const VerilatedVar* varp, const VerilatedScope* scopep)
        : m_varp{varp}
-        , m_scopep{scopep} {}
+        , m_scopep{scopep}
+        , m_fullname{std::string{m_scopep->name()} + '.' + m_varp->name()} {}
    explicit VerilatedVpioVarBase(const VerilatedVpioVarBase* varp) {
        if (varp) {
            m_varp = varp->m_varp;
            m_scopep = varp->m_scopep;
+            m_fullname = varp->m_fullname;
        }
    }
    static VerilatedVpioVarBase* castp(vpiHandle h) {
@@ -188,11 +191,7 @@ public:
    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 thread_local std::string t_out;
-        t_out = std::string{m_scopep->name()} + "." + name();
-        return t_out.c_str();
-    }
+    const char* fullname() const override { return m_fullname.c_str(); }
 };

 class VerilatedVpioParam final : public VerilatedVpioVarBase {
@@ -646,23 +645,21 @@ public:
                continue;
            }
            VerilatedVpiCbHolder& ho = *it++;
-            if (VerilatedVpioVar* const varop = VerilatedVpioVar::castp(ho.cb_datap()->obj)) {
-                void* const newDatap = varop->varDatap();
-                void* const prevDatap
-                    = varop->prevDatap();  // Was malloced when we added the callback
-                VL_DEBUG_IF_PLI(VL_DBG_MSGF("- vpi: value_test %s v[0]=%d/%d %p %p\n",
-                                            varop->fullname(), *(static_cast<CData*>(newDatap)),
-                                            *(static_cast<CData*>(prevDatap)), newDatap,
-                                            prevDatap););
-                if (std::memcmp(prevDatap, newDatap, varop->entSize()) != 0) {
-                    VL_DEBUG_IF_PLI(VL_DBG_MSGF("- vpi: value_callback %" PRId64 " %s v[0]=%d\n",
-                                                ho.id(), varop->fullname(),
-                                                *(static_cast<CData*>(newDatap))););
-                    update.insert(varop);
-                    vpi_get_value(ho.cb_datap()->obj, ho.cb_datap()->value);
-                    (ho.cb_rtnp())(ho.cb_datap());
-                    called = true;
-                }
+            VerilatedVpioVar* const varop
+                = reinterpret_cast<VerilatedVpioVar*>(ho.cb_datap()->obj);
+            void* const newDatap = varop->varDatap();
+            void* const prevDatap = varop->prevDatap();  // Was malloced when we added the callback
+            VL_DEBUG_IF_PLI(VL_DBG_MSGF("- vpi: value_test %s v[0]=%d/%d %p %p\n",
+                                        varop->fullname(), *(static_cast<CData*>(newDatap)),
+                                        *(static_cast<CData*>(prevDatap)), newDatap, prevDatap););
+            if (std::memcmp(prevDatap, newDatap, varop->entSize()) != 0) {
+                VL_DEBUG_IF_PLI(VL_DBG_MSGF("- vpi: value_callback %" PRId64 " %s v[0]=%d\n",
+                                            ho.id(), varop->fullname(),
+                                            *(static_cast<CData*>(newDatap))););
+                update.insert(varop);
+                vpi_get_value(ho.cb_datap()->obj, ho.cb_datap()->value);
+                (ho.cb_rtnp())(ho.cb_datap());
+                called = true;
            }
            if (was_last) break;
        }
@@ -791,7 +788,6 @@ void VerilatedVpiImp::dumpCbs() VL_MT_UNSAFE_ONE {
    }
    for (auto& ifuture : s().m_nextCbs) {
        const QData time = ifuture.first.first;
-        const uint64_t id = ifuture.first.second;
        VerilatedVpiCbHolder& ho = ifuture.second;
        if (VL_UNLIKELY(!ho.invalid())) {
            VL_DBG_MSGF("- vpi:   time=%" PRId64 "(NEXT) reason=%d=%s  id=%" PRId64 "\n", time,
@@ -802,7 +798,6 @@ void VerilatedVpiImp::dumpCbs() VL_MT_UNSAFE_ONE {
    }
    for (auto& ifuture : s().m_futureCbs) {
        const QData time = ifuture.first.first;
-        const uint64_t id = ifuture.first.second;
        VerilatedVpiCbHolder& ho = ifuture.second;
        if (VL_UNLIKELY(!ho.invalid())) {
            VL_DBG_MSGF("- vpi:   time=%" PRId64 " reason=%d=%s  id=%" PRId64 "\n", time,
@@ -2312,7 +2307,7 @@ PLI_INT32 vpi_flush(void) {
    VerilatedVpiImp::assertOneCheck();
    VL_VPI_ERROR_RESET_();
    Verilated::runFlushCallbacks();
-    return 0;
+    return 0;  // Gcc coverage bug // LCOV_EXCL_LINE
 }

 PLI_INT32 vpi_mcd_flush(PLI_UINT32 mcd) {
@@ -37,8 +37,13 @@
 //=========================================================================
 // Compiler pragma abstraction

+#if defined(__clang__)
+# define VL_CLANG_ATTR(attr) __attribute__(( attr ))
+#else
+# define VL_CLANG_ATTR(attr)
+#endif
+
 #ifdef __GNUC__
-# define VL_ATTR_ALIGNED(alignment) __attribute__((aligned(alignment)))
 # define VL_ATTR_ALWINLINE __attribute__((always_inline)) inline
 # define VL_ATTR_NOINLINE __attribute__((noinline))
 # define VL_ATTR_COLD __attribute__((cold))
@@ -57,19 +62,6 @@
 // All VL_ATTR_WEAK symbols must be marked with the macOS -U linker flag in verilated.mk.in
 #  define VL_ATTR_WEAK __attribute__((weak))
 # endif
-# if defined(__clang__)
-#  define VL_ACQUIRE(...) __attribute__((annotate("ACQUIRE"))) __attribute__((acquire_capability(__VA_ARGS__)))
-#  define VL_ACQUIRE_SHARED(...) __attribute__((annotate("ACQUIRE_SHARED"))) __attribute__((acquire_shared_capability(__VA_ARGS__)))
-#  define VL_RELEASE(...) __attribute__((annotate("RELEASE"))) __attribute__((release_capability(__VA_ARGS__)))
-#  define VL_RELEASE_SHARED(...) __attribute__((annotate("RELEASE_SHARED"))) __attribute__((release_shared_capability(__VA_ARGS__)))
-#  define VL_TRY_ACQUIRE(...) __attribute__((try_acquire_capability(__VA_ARGS__)))
-#  define VL_TRY_ACQUIRE_SHARED(...) __attribute__((try_acquire_shared_capability(__VA_ARGS__)))
-#  define VL_CAPABILITY(x) __attribute__((capability(x)))
-#  define VL_REQUIRES(x) __attribute__((annotate("REQUIRES"))) __attribute__((requires_capability(x)))
-#  define VL_GUARDED_BY(x) __attribute__((annotate("GUARDED_BY"))) __attribute__((guarded_by(x)))
-#  define VL_EXCLUDES(x) __attribute__((annotate("EXCLUDES"))) __attribute__((locks_excluded(x)))
-#  define VL_SCOPED_CAPABILITY __attribute__((scoped_lockable))
-# endif
 # define VL_LIKELY(x) __builtin_expect(!!(x), 1)  // Prefer over C++20 [[likely]]
 # define VL_UNLIKELY(x) __builtin_expect(!!(x), 0)  // Prefer over C++20 [[unlikely]]
 # define VL_UNREACHABLE __builtin_unreachable()  // C++23 std::unreachable()
@@ -77,10 +69,74 @@
 # define VL_PREFETCH_RW(p) __builtin_prefetch((p), 1)
 #endif

-// Defaults for unsupported compiler features
-#ifndef VL_ATTR_ALIGNED
-# define VL_ATTR_ALIGNED(alignment)  ///< Attribute to align structure to byte alignment
+// Function acquires a capability/lock (-fthread-safety)
+#define VL_ACQUIRE(...) \
+        VL_CLANG_ATTR(annotate("ACQUIRE")) \
+        VL_CLANG_ATTR(acquire_capability(__VA_ARGS__))
+// Function acquires a shared capability/lock (-fthread-safety)
+#define VL_ACQUIRE_SHARED(...) \
+        VL_CLANG_ATTR(annotate("ACQUIRE_SHARED")) \
+        VL_CLANG_ATTR(acquire_shared_capability(__VA_ARGS__))
+// Function releases a capability/lock (-fthread-safety)
+#define VL_RELEASE(...) \
+        VL_CLANG_ATTR(annotate("RELEASE")) \
+        VL_CLANG_ATTR(release_capability(__VA_ARGS__))
+// Function releases a shared capability/lock (-fthread-safety)
+#define VL_RELEASE_SHARED(...) \
+        VL_CLANG_ATTR(annotate("RELEASE_SHARED")) \
+        VL_CLANG_ATTR(release_shared_capability(__VA_ARGS__))
+// Function returns bool if acquired a capability (-fthread-safety)
+#define VL_TRY_ACQUIRE(...) \
+        VL_CLANG_ATTR(try_acquire_capability(__VA_ARGS__))
+// Function returns bool if acquired shared (-fthread-safety)
+#define VL_TRY_ACQUIRE_SHARED(...) \
+        VL_CLANG_ATTR(try_acquire_shared_capability(__VA_ARGS__))
+// Function requires a capability inbound (-fthread-safety)
+#define VL_CAPABILITY(x) \
+        VL_CLANG_ATTR(capability(x))
+// Name of mutex protecting this variable (-fthread-safety)
+#define VL_EXCLUDES(x) \
+        VL_CLANG_ATTR(annotate("EXCLUDES")) \
+        VL_CLANG_ATTR(locks_excluded(x))
+// Scoped threaded capability/lock (-fthread-safety)
+#define VL_SCOPED_CAPABILITY \
+        VL_CLANG_ATTR(scoped_lockable)
+// Annotated function returns reference to the given capability.
+// Allowed on: function, method. (-fthread-safety)
+#define VL_RETURN_CAPABILITY(x) \
+        VL_CLANG_ATTR(lock_returned(x))
+// Assert that capability is already held.
+// Allowed on: function, method. (-fthread-safety)
+#define VL_ASSERT_CAPABILITY(x) \
+        VL_CLANG_ATTR(assert_capability(x))
+
+// Require mutex locks only in code units which work with enabled multi-threading.
+#if !defined(VL_MT_DISABLED_CODE_UNIT)
+// Function requires not having a capability inbound (-fthread-safety)
+# define VL_REQUIRES(x) \
+        VL_CLANG_ATTR(annotate("REQUIRES")) \
+        VL_CLANG_ATTR(requires_capability(x))
+// Name of capability/lock (-fthread-safety)
+# define VL_GUARDED_BY(x) \
+        VL_CLANG_ATTR(annotate("GUARDED_BY")) \
+        VL_CLANG_ATTR(guarded_by(x))
+// The data that the annotated pointer points to is protected by the given capability.
+// The pointer itself is not protected.
+// Allowed on: pointer data member. (-fthread-safety)
+# define VL_PT_GUARDED_BY(x) \
+        VL_CLANG_ATTR(annotate("PT_GUARDED_BY")) \
+        VL_CLANG_ATTR(pt_guarded_by(x))
+#else
+// Keep annotations for clang_check_attributes
+# define VL_REQUIRES(x) \
+        VL_CLANG_ATTR(annotate("REQUIRES"))
+# define VL_GUARDED_BY(x) \
+        VL_CLANG_ATTR(annotate("GUARDED_BY"))
+# define VL_PT_GUARDED_BY(x) \
+        VL_CLANG_ATTR(annotate("PT_GUARDED_BY"))
 #endif
+
+// Defaults for unsupported compiler features
 #ifndef VL_ATTR_ALWINLINE
 # define VL_ATTR_ALWINLINE  ///< Attribute to inline, even when not optimizing
 #endif
@@ -111,19 +167,6 @@
 #ifndef VL_ATTR_WEAK
 # define VL_ATTR_WEAK  ///< Attribute that function external that is optionally defined
 #endif
-#ifndef VL_CAPABILITY
-# define VL_ACQUIRE(...)  ///< Function acquires a capability/lock (-fthread-safety)
-# define VL_ACQUIRE_SHARED(...)  ///< Function acquires a shared capability/lock (-fthread-safety)
-# define VL_RELEASE(...)  ///< Function releases a capability/lock (-fthread-safety)
-# define VL_RELEASE_SHARED(...)  ///< Function releases a shared capability/lock (-fthread-safety)
-# define VL_TRY_ACQUIRE(...)  ///< Function returns bool if acquired a capability (-fthread-safety)
-# define VL_TRY_ACQUIRE_SHARED(...)  ///< Function returns bool if acquired shared (-fthread-safety)
-# define VL_REQUIRES(x)  ///< Function requires a capability inbound (-fthread-safety)
-# define VL_EXCLUDES(x)  ///< Function requires not having a capability inbound (-fthread-safety)
-# define VL_CAPABILITY(x)  ///< Name of capability/lock (-fthread-safety)
-# define VL_GUARDED_BY(x)  ///< Name of mutex protecting this variable (-fthread-safety)
-# define VL_SCOPED_CAPABILITY  ///< Scoped threaded capability/lock (-fthread-safety)
-#endif
 #ifndef VL_LIKELY
 # define VL_LIKELY(x) (!!(x))  ///< Return boolean expression that is more often true
 # define VL_UNLIKELY(x) (!!(x))  ///< Return boolean expression that is more often false
@@ -142,6 +185,7 @@


 #ifndef VL_NO_LEGACY
+# define VL_ATTR_ALIGNED(alignment)  // Deprecated
 # define VL_FUNC __func__  // Deprecated
 # define VL_THREAD  // Deprecated
 # define VL_THREAD_LOCAL thread_local  // Deprecated
@@ -149,49 +193,24 @@
 #endif

 // Comment tag that Function is pure (and thus also VL_MT_SAFE)
-#if defined(__clang__)
-# define VL_PURE __attribute__((annotate("PURE")))
-#else
-# define VL_PURE
-#endif
+#define VL_PURE VL_CLANG_ATTR(annotate("PURE"))
 // Comment tag that function is threadsafe
-#if defined(__clang__)
-# define VL_MT_SAFE __attribute__((annotate("MT_SAFE")))
-#else
-# define VL_MT_SAFE
-#endif
+#define VL_MT_SAFE VL_CLANG_ATTR(annotate("MT_SAFE"))
+// Comment tag that function is threadsafe, only if
+// other threads doesn't change tree topology
+#define VL_MT_STABLE VL_CLANG_ATTR(annotate("MT_STABLE"))
 // Comment tag that function is threadsafe, only
 // during normal operation (post-init)
-#if defined(__clang__)
-# define VL_MT_SAFE_POSTINIT __attribute__((annotate("MT_SAFE_POSTINIT")))
-#else
-# define VL_MT_SAFE_POSTINIT
-#endif
+#define VL_MT_SAFE_POSTINIT VL_CLANG_ATTR(annotate("MT_SAFE_POSTINIT"))
 // Attribute that function is clang threadsafe and uses given mutex
-#if defined(__clang__)
-# define VL_MT_SAFE_EXCLUDES(mutex) __attribute__((annotate("MT_SAFE_EXCLUDES"))) VL_EXCLUDES(mutex)
-#else
-# define VL_MT_SAFE_EXCLUDES(mutex) VL_EXCLUDES(mutex)
-#endif
+#define VL_MT_SAFE_EXCLUDES(mutex) VL_CLANG_ATTR(annotate("MT_SAFE_EXCLUDES")) VL_EXCLUDES(mutex)
 // Comment tag that function is not threadsafe
-#if defined(__clang__)
-# define VL_MT_UNSAFE __attribute__((annotate("MT_UNSAFE")))
-#else
-# define VL_MT_UNSAFE
-#endif
+#define VL_MT_UNSAFE VL_CLANG_ATTR(annotate("MT_UNSAFE"))
 // Comment tag that function is not threadsafe
 // protected to make sure single-caller
-#if defined(__clang__)
-# define VL_MT_UNSAFE_ONE __attribute__((annotate("MT_UNSAFE_ONE")))
-#else
-# define VL_MT_UNSAFE_ONE
-#endif
+#define VL_MT_UNSAFE_ONE VL_CLANG_ATTR(annotate("MT_UNSAFE_ONE"))
 // Comment tag that function is entry point of parallelization
-#if defined(__clang__)
-# define VL_MT_START __attribute__((annotate("MT_START")))
-#else
-# define VL_MT_START
-#endif
+#define VL_MT_START VL_CLANG_ATTR(annotate("MT_START"))

 #ifndef VL_NO_LEGACY
 # define VL_ULL(c) (c##ULL)  // Add appropriate suffix to 64-bit constant (deprecated)
@@ -317,6 +336,7 @@ extern "C" void __gcov_dump();
 // Now that C++ requires these standard types the vl types are deprecated
 #include <cstdint>
 #include <cinttypes>
+#include <cmath>

 #ifndef VL_NO_LEGACY
 using vluint8_t = uint8_t;  ///< 8-bit unsigned type (backward compatibility)
@@ -422,6 +442,11 @@ using ssize_t = uint32_t;  ///< signed size_t; returned from read()
    Type(const Type& other) = delete; \
    Type& operator=(const Type&) = delete

+// Declare a class as unmovable; put after a private:
+#define VL_UNMOVABLE(Type) \
+    Type(Type&& other) = delete; \
+    Type& operator=(Type&&) = delete
+
 //=========================================================================
 // Verilated function size macros

@@ -441,11 +466,14 @@ using ssize_t = uint32_t;  ///< signed size_t; returned from read()
 #define VL_SIZEBITS_E (VL_EDATASIZE - 1)  ///< Bit mask for bits in a quad

 /// Return mask for words with 1's where relevant bits are (0=all bits)
+/// Arguments must not have side effects
 #define VL_MASK_I(nbits) (((nbits) & VL_SIZEBITS_I) ? ((1U << ((nbits) & VL_SIZEBITS_I)) - 1) : ~0)
 /// Return mask for quads with 1's where relevant bits are (0=all bits)
+/// Arguments must not have side effects
 #define VL_MASK_Q(nbits) \
    (((nbits) & VL_SIZEBITS_Q) ? ((1ULL << ((nbits) & VL_SIZEBITS_Q)) - 1ULL) : ~0ULL)
 /// Return mask for EData with 1's where relevant bits are (0=all bits)
+/// Arguments must not have side effects
 #define VL_MASK_E(nbits) VL_MASK_I(nbits)

 #define VL_EUL(n) VL_UL(n)  // Make constant number EData sized
@@ -467,8 +495,12 @@ using ssize_t = uint32_t;  ///< signed size_t; returned from read()
 // #defines, to avoid requiring math.h on all compile runs

 #ifdef _MSC_VER
-# define VL_TRUNC(n) (((n) < 0) ? std::ceil((n)) : std::floor((n)))
-# define VL_ROUND(n) (((n) < 0) ? std::ceil((n)-0.5) : std::floor((n) + 0.5))
+static inline double VL_TRUNC(double n) {
+    return (n < 0) ? std::ceil(n) : std::floor(n);
+}
+static inline double VL_ROUND(double n) {
+    return (n < 0) ? std::ceil(n-0.5) : std::floor(n + 0.5);
+}
 #else
 # define VL_TRUNC(n) std::trunc(n)
 # define VL_ROUND(n) std::round(n)
@@ -562,8 +594,8 @@ using ssize_t = uint32_t;  ///< signed size_t; returned from read()
 //=========================================================================
 // Stringify macros

-#define VL_STRINGIFY(x) VL_STRINGIFY2(x)
-#define VL_STRINGIFY2(x) #x
+#define VL_STRINGIFY(...) VL_STRINGIFY2(__VA_ARGS__)
+#define VL_STRINGIFY2(...) #__VA_ARGS__

 //=========================================================================
 // Offset of field in type
@@ -596,8 +628,12 @@ reverse_wrapper<T> reverse_view(const T& v) {
 }

 // C++17's std::as_const
+// `VL_MT_SAFE` annotation only applies to this function.
+// Object that is returned by this function is not considered
+// as MT_SAFE and any function call on this object still
+// needs to be `VL_MT_SAFE`.
 template <class T>
-T const& as_const(T& v) {
+T const& as_const(T& v) VL_MT_SAFE {
    return v;
 }

@@ -10,16 +10,36 @@ import argparse
 import os
 import sys
 import shlex
-from typing import Callable, Iterable, Optional, Union
+from typing import Callable, Iterable, Optional, Union, TYPE_CHECKING
 import dataclasses
 from dataclasses import dataclass
 import enum
 from enum import Enum
 import multiprocessing
+import re
 import tempfile

 import clang.cindex
-from clang.cindex import CursorKind, Index, TranslationUnitSaveError, TranslationUnitLoadError
+from clang.cindex import (
+    Index,
+    TranslationUnitSaveError,
+    TranslationUnitLoadError,
+    CompilationDatabase,
+)
+
+if not TYPE_CHECKING:
+    from clang.cindex import CursorKind
+else:
+    # Workaround for missing support for members defined out-of-class in Pylance:
+    # https://github.com/microsoft/pylance-release/issues/2365#issuecomment-1035803067
+
+    class CursorKindMeta(type):
+
+        def __getattr__(cls, name: str) -> clang.cindex.CursorKind:
+            return getattr(clang.cindex.CursorKind, name)
+
+    class CursorKind(clang.cindex.CursorKind, metaclass=CursorKindMeta):
+        pass


 def fully_qualified_name(node):
@@ -33,12 +53,34 @@ def fully_qualified_name(node):
    return [node.displayname] if node.displayname else []


+# Returns True, if `class_node` contains node
+# that matches `member` spelling
+def check_class_member_exists(class_node, member):
+    for child in class_node.get_children():
+        if member.spelling == child.spelling:
+            return True
+    return False
+
+
+# Returns Base class (if found) of `class_node`
+# that is of type `base_type`
+def get_base_class(class_node, base_type):
+    for child in class_node.get_children():
+        if child.kind is CursorKind.CXX_BASE_SPECIFIER:
+            base_class = child.type
+            if base_type.spelling == base_class.spelling:
+                return base_class
+    return None
+
+
@dataclass
 class VlAnnotations:
    mt_start: bool = False
    mt_safe: bool = False
+    stable_tree: bool = False
    mt_safe_postinit: bool = False
    mt_unsafe: bool = False
+    mt_disabled: bool = False
    mt_unsafe_one: bool = False
    pure: bool = False
    guarded: bool = False
@@ -48,14 +90,19 @@ class VlAnnotations:
    release: bool = False

    def is_mt_safe_context(self):
-        return (not (self.mt_unsafe or self.mt_unsafe_one)
-                and (self.mt_safe or self.mt_start))
+        return self.mt_safe and not (self.mt_unsafe or self.mt_unsafe_one)

    def is_pure_context(self):
        return self.pure

+    def is_stabe_tree_context(self):
+        # stable tree context requires calls to be marked
+        # as MT_SAFE or MT_STABLE
+        # Functions in MT_START needs to be MT_SAFE or MT_STABLE
+        return self.stable_tree or self.mt_start
+
    def is_mt_unsafe_call(self):
-        return self.mt_unsafe or self.mt_unsafe_one
+        return self.mt_unsafe or self.mt_unsafe_one or self.mt_disabled

    def is_mt_safe_call(self):
        return (not self.is_mt_unsafe_call()
@@ -66,6 +113,9 @@ class VlAnnotations:
    def is_pure_call(self):
        return self.pure

+    def is_stabe_tree_call(self):
+        return self.stable_tree
+
    def __or__(self, other: "VlAnnotations"):
        result = VlAnnotations()
        for key, value in dataclasses.asdict(self).items():
@@ -94,12 +144,16 @@ class VlAnnotations:
                    result.mt_start = True
                elif node.displayname == "MT_SAFE":
                    result.mt_safe = True
+                elif node.displayname == "MT_STABLE":
+                    result.stable_tree = True
                elif node.displayname == "MT_SAFE_POSTINIT":
                    result.mt_safe_postinit = True
                elif node.displayname == "MT_UNSAFE":
                    result.mt_unsafe = True
                elif node.displayname == "MT_UNSAFE_ONE":
                    result.mt_unsafe_one = True
+                elif node.displayname == "MT_DISABLED":
+                    result.mt_disabled = True
                elif node.displayname == "PURE":
                    result.pure = True
                elif node.displayname in ["ACQUIRE", "ACQUIRE_SHARED"]:
@@ -172,6 +226,19 @@ class FunctionInfo:
    def copy(self, /, **changes):
        return dataclasses.replace(self, **changes)

+    @staticmethod
+    def from_decl_file_line_and_refd_node(file: str, line: int,
+                                          refd: clang.cindex.Cursor,
+                                          annotations: VlAnnotations):
+        file = os.path.abspath(file)
+        refd = refd.canonical
+        assert refd is not None
+        name_parts = fully_qualified_name(refd)
+        usr = refd.get_usr()
+        ftype = FunctionType.from_node(refd)
+
+        return FunctionInfo(name_parts, usr, file, line, annotations, ftype)
+
    @staticmethod
    def from_node(node: clang.cindex.Cursor,
                  refd: Optional[clang.cindex.Cursor] = None,
@@ -196,6 +263,8 @@ class DiagnosticKind(Enum):
    ANNOTATIONS_DEF_DECL_MISMATCH = enum.auto()
    NON_PURE_CALL_IN_PURE_CTX = enum.auto()
    NON_MT_SAFE_CALL_IN_MT_SAFE_CTX = enum.auto()
+    NON_STABLE_TREE_CALL_IN_STABLE_TREE_CTX = enum.auto()
+    MISSING_MT_DISABLED_ANNOTATION = enum.auto()

    def __lt__(self, other):
        return self.value < other.value
@@ -233,13 +302,109 @@ class CallAnnotationsValidator:

        self._index = Index.create()

-        self._processed_headers: set[str] = set()
+        # Map key represents translation unit initial defines
+        # (from command line and source's lines before any include)
+        self._processed_headers: dict[str, set[str]] = {}
+        self._external_decls: dict[str, set[tuple[str, int]]] = {}

        # Current context
+        self._main_source_file: str = ""
+        self._defines: dict[str, str] = {}
        self._call_location: Optional[FunctionInfo] = None
        self._caller: Optional[FunctionInfo] = None
+        self._constructor_context: list[clang.cindex.Cursor] = []
        self._level: int = 0
-        self._constructor_context: int = 0
+
+    def is_mt_disabled_code_unit(self):
+        return "VL_MT_DISABLED_CODE_UNIT" in self._defines
+
+    def is_constructor_context(self):
+        return len(self._constructor_context) > 0
+
+    # Parses all lines in a form: `#define KEY VALUE` located before any `#include` line.
+    # The parsing is very simple, there is no support for line breaks, etc.
+    @staticmethod
+    def parse_initial_defines(source_file: str) -> dict[str, str]:
+        defs: dict[str, str] = {}
+        with open(source_file, "r", encoding="utf-8") as file:
+            for line in file:
+                line = line.strip()
+                match = re.fullmatch(
+                    r"^#\s*(define\s+(\w+)(?:\s+(.*))?|include\s+.*)$", line)
+                if match:
+                    if match.group(1).startswith("define"):
+                        key = match.group(2)
+                        value = match.groups("1")[2]
+                        defs[key] = value
+                    elif match.group(1).startswith("include"):
+                        break
+        return defs
+
+    @staticmethod
+    def filter_out_unsupported_compiler_args(
+            args: list[str]) -> tuple[list[str], dict[str, str]]:
+        filtered_args = []
+        defines = {}
+        args_iter = iter(args)
+        try:
+            while arg := next(args_iter):
+                # Skip positional arguments (input file name).
+                if not arg.startswith("-") and (arg.endswith(".cpp")
+                                                or arg.endswith(".c")
+                                                or arg.endswith(".h")):
+                    continue
+
+                # Skipped options with separate value argument.
+                if arg in ["-o", "-T", "-MT", "-MQ", "-MF"
+                           "-L"]:
+                    next(args_iter)
+                    continue
+
+                # Skipped options without separate value argument.
+                if arg == "-c" or arg.startswith("-W") or arg.startswith("-L"):
+                    continue
+
+                # Preserved options with separate value argument.
+                if arg in [
+                        "-x"
+                        "-Xclang", "-I", "-isystem", "-iquote", "-include",
+                        "-include-pch"
+                ]:
+                    filtered_args += [arg, next(args_iter)]
+                    continue
+
+                kv_str = None
+                d_or_u = None
+                # Preserve define/undefine with separate value argument.
+                if arg in ["-D", "-U"]:
+                    filtered_args.append(arg)
+                    d_or_u = arg[1]
+                    kv_str = next(args_iter)
+                    filtered_args.append(kv_str)
+                # Preserve define/undefine without separate value argument.
+                elif arg[0:2] in ["-D", "-U"]:
+                    filtered_args.append(arg)
+                    kv_str = arg[2:]
+                    d_or_u = arg[1]
+                # Preserve everything else.
+                else:
+                    filtered_args.append(arg)
+                    continue
+
+                # Keep track of defines for class' internal purposes.
+                key_value = kv_str.split("=", 1)
+                key = key_value[0]
+                val = "1" if len(key_value) == 1 else key_value[1]
+
+                if d_or_u == "D":
+                    defines[key] = val
+                elif d_or_u == "U" and key in defines:
+                    del defines[key]
+
+        except StopIteration:
+            pass
+
+        return (filtered_args, defines)

    def compile_and_analyze_file(self, source_file: str,
                                 compiler_args: list[str],
@@ -247,18 +412,32 @@ class CallAnnotationsValidator:
        filename = os.path.abspath(source_file)
        initial_cwd = "."

+        filtered_args, defines = self.filter_out_unsupported_compiler_args(
+            compiler_args)
+        defines.update(self.parse_initial_defines(source_file))
+
        if build_dir:
            initial_cwd = os.getcwd()
            os.chdir(build_dir)
-        translation_unit = self._index.parse(filename, compiler_args)
-        has_errors = False
-        for diag in translation_unit.diagnostics:
-            if diag.severity > clang.cindex.Diagnostic.Error:
-                has_errors = True
-        if translation_unit and not has_errors:
+        try:
+            translation_unit = self._index.parse(filename, filtered_args)
+        except TranslationUnitLoadError:
+            translation_unit = None
+        errors = []
+        if translation_unit:
+            for diag in translation_unit.diagnostics:
+                if diag.severity >= clang.cindex.Diagnostic.Error:
+                    errors.append(str(diag))
+        if translation_unit and len(errors) == 0:
+            self._defines = defines
+            self._main_source_file = filename
            self.process_translation_unit(translation_unit)
+            self._main_source_file = ""
+            self._defines = {}
        else:
            print(f"%Error: parsing failed: {filename}", file=sys.stderr)
+            for error in errors:
+                print(f"        {error}", file=sys.stderr)
        if build_dir:
            os.chdir(initial_cwd)

@@ -329,7 +508,7 @@ class CallAnnotationsValidator:
                    return None

            refn = find_object_ref(node)
-            if self._constructor_context and not refn:
+            if self.is_constructor_context() and not refn:
                # we are in constructor and no object reference means
                # we are calling local method. It is MT safe
                # only if this method is also only calling local methods or
@@ -341,20 +520,44 @@ class CallAnnotationsValidator:
            elif refn and refn.kind == CursorKind.MEMBER_REF_EXPR and refn.referenced:
                refn = refn.referenced
                refna = VlAnnotations.from_nodes_list(refn.get_children())
-                if refna.guarded or self._constructor_context:
+                if refna.guarded:
                    is_mt_safe = True
+                if self.is_constructor_context() and refn.semantic_parent:
+                    # we are in constructor, so calling local members is MT_SAFE,
+                    # make sure object that we are calling is local to the constructor
+                    constructor_class = self._constructor_context[
+                        -1].semantic_parent
+                    if refn.semantic_parent.spelling == constructor_class.spelling:
+                        if check_class_member_exists(constructor_class, refn):
+                            is_mt_safe = True
+                    else:
+                        # check if this class inherits from some base class
+                        base_class = get_base_class(constructor_class,
+                                                    refn.semantic_parent)
+                        if base_class:
+                            if check_class_member_exists(
+                                    base_class.get_declaration(), refn):
+                                is_mt_safe = True
            # variable
            elif refn and refn.kind == CursorKind.DECL_REF_EXPR and refn.referenced:
-                # This is probably a local or an argument.
-                # Calling methods on local pointers or references is MT-safe,
-                # but on argument pointers or references is not.
-                if "*" not in refn.type.spelling and "&" not in refn.type.spelling:
-                    is_mt_safe = True
-                # local variable
-                if refn.referenced.kind == CursorKind.VAR_DECL:
-                    is_mt_safe = True
+                if refn.get_definition():
+                    if refn.referenced.semantic_parent:
+                        if refn.referenced.semantic_parent.kind in [
+                                CursorKind.FUNCTION_DECL, CursorKind.CXX_METHOD
+                        ]:
+                            # This is a local or an argument.
+                            # Calling methods on local pointers or references is MT-safe,
+                            # but on argument pointers or references is not.
+                            if "*" not in refn.type.spelling and "&" not in refn.type.spelling:
+                                is_mt_safe = True
+                            # local variable
+                            if refn.referenced.kind == CursorKind.VAR_DECL:
+                                is_mt_safe = True
+                else:
+                    # Global variable in different translation unit, unsafe
+                    pass
            elif refn and refn.kind == CursorKind.CALL_EXPR:
-                if self._constructor_context:
+                if self.is_constructor_context():
                    # call to local function from constructor context
                    # safe if this function also calling local methods or
                    # MT-safe methods
@@ -377,6 +580,17 @@ class CallAnnotationsValidator:
                    FunctionInfo.from_node(refd, refd, annotations),
                    DiagnosticKind.NON_MT_SAFE_CALL_IN_MT_SAFE_CTX)

+        # stable tree context
+        if ctx.is_stabe_tree_context():
+            if annotations.is_mt_unsafe_call() or not (
+                    annotations.is_stabe_tree_call()
+                    or annotations.is_pure_call()
+                    or self.check_mt_safe_call(node, refd, annotations)):
+                self.emit_diagnostic(
+                    FunctionInfo.from_node(refd, refd, annotations),
+                    DiagnosticKind.NON_STABLE_TREE_CALL_IN_STABLE_TREE_CTX)
+
+        # pure context
        if ctx.is_pure_context():
            if not annotations.is_pure_call():
                self.emit_diagnostic(
@@ -394,6 +608,17 @@ class CallAnnotationsValidator:
                self.emit_diagnostic(
                    FunctionInfo.from_node(refd, refd, annotations),
                    DiagnosticKind.NON_MT_SAFE_CALL_IN_MT_SAFE_CTX)
+
+        # stable tree context
+        if ctx.is_stabe_tree_context():
+            if annotations.is_mt_unsafe_call() or not (
+                    annotations.is_pure_call()
+                    or annotations.is_mt_safe_call()
+                    or annotations.is_stabe_tree_call()):
+                self.emit_diagnostic(
+                    FunctionInfo.from_node(refd, refd, annotations),
+                    DiagnosticKind.NON_STABLE_TREE_CALL_IN_STABLE_TREE_CTX)
+
        # pure context
        if ctx.is_pure_context():
            if not annotations.is_pure_call():
@@ -408,11 +633,18 @@ class CallAnnotationsValidator:

        # Constructors are OK in MT-safe context
        # only if they call local methods or MT-safe functions.
-        if ctx.is_mt_safe_context() or self._constructor_context:
-            self._constructor_context += 1
+        if ctx.is_mt_safe_context() or self.is_constructor_context():
+            self._constructor_context.append(refd)
            self.iterate_children(refd.get_children(),
                                  self.dispatch_node_inside_definition)
-            self._constructor_context -= 1
+            self._constructor_context.pop()
+
+        # stable tree context
+        if ctx.is_stabe_tree_context():
+            self._constructor_context.append(refd)
+            self.iterate_children(refd.get_children(),
+                                  self.dispatch_node_inside_definition)
+            self._constructor_context.pop()

        # pure context
        if ctx.is_pure_context():
@@ -428,11 +660,19 @@ class CallAnnotationsValidator:
        if not supported:
            self.iterate_children(node.get_children(),
                                  self.dispatch_node_inside_definition)
-            return
+            return True

        assert refd is not None
        if self._is_ignored_call(refd):
-            return
+            return True
+
+        if "std::function" in refd.displayname:
+            # Workaroud for missing support for lambda annotations
+            # in c++11.
+            # If function takes std::function as argument,
+            # assume, that this std::function will be called inside it.
+            self.process_function_definition(node)
+            return False

        assert self._call_location is not None
        node_file = os.path.abspath(node.location.file.name)
@@ -444,47 +684,52 @@ class CallAnnotationsValidator:
                or refd.kind == CursorKind.CXX_METHOD
                and refd.is_static_method()):
            self.process_function_call(refd, annotations)
-            self.iterate_children(node.get_children(),
-                                  self.dispatch_node_inside_definition)
-            return
        # Function pointer
-        if refd.kind in [
+        elif refd.kind in [
                CursorKind.VAR_DECL, CursorKind.FIELD_DECL,
                CursorKind.PARM_DECL
        ]:
            self.process_function_call(refd, annotations)
-            self.iterate_children(node.get_children(),
-                                  self.dispatch_node_inside_definition)
-            return
        # Non-static class methods
-        if refd.kind == CursorKind.CXX_METHOD:
+        elif refd.kind == CursorKind.CXX_METHOD:
            self.process_method_call(node, refd, annotations)
-            self.iterate_children(node.get_children(),
-                                  self.dispatch_node_inside_definition)
-            return
        # Conversion method (e.g. `operator int()`)
-        if refd.kind == CursorKind.CONVERSION_FUNCTION:
+        elif refd.kind == CursorKind.CONVERSION_FUNCTION:
            self.process_method_call(node, refd, annotations)
-            self.iterate_children(node.get_children(),
-                                  self.dispatch_node_inside_definition)
-            return
        # Constructors
-        if refd.kind == CursorKind.CONSTRUCTOR:
+        elif refd.kind == CursorKind.CONSTRUCTOR:
            self.process_constructor_call(refd, annotations)
-            self.iterate_children(node.get_children(),
-                                  self.dispatch_node_inside_definition)
-            return
+        else:
+            # Ignore other callables, but report them
+            print("Unknown callable: "
+                  f"{refd.location.file.name}:{refd.location.line}: "
+                  f"{refd.displayname}    {refd.kind}\n"
+                  f"    from: {node.location.file.name}:{node.location.line}")
+        return True

-        # Ignore other callables
-        print(f"{refd.location.file.name}:{refd.location.line}: "
-              f"{refd.displayname}    {refd.kind}\n"
-              f"    from: {node.location.file.name}:{node.location.line}")
+    def process_function_declaration(self, node: clang.cindex.Cursor):
+        # Ignore declarations in main .cpp file
+        if node.location.file.name != self._main_source_file:
+            children = list(node.get_children())
+            annotations = VlAnnotations.from_nodes_list(children)
+            if not annotations.mt_disabled:
+                self._external_decls.setdefault(node.get_usr(), set()).add(
+                    (str(node.location.file.name), int(node.location.line)))
+            return self.iterate_children(children, self.dispatch_node)
+
+        return self.iterate_children(node.get_children(), self.dispatch_node)

    # Definition handling

    def dispatch_node_inside_definition(self, node: clang.cindex.Cursor):
        if node.kind == CursorKind.CALL_EXPR:
-            self.dispatch_call_node(node)
+            if self.dispatch_call_node(node) is False:
+                return None
+        elif node.is_definition() and node.kind in [
+                CursorKind.CXX_METHOD, CursorKind.FUNCTION_DECL,
+                CursorKind.CONSTRUCTOR, CursorKind.CONVERSION_FUNCTION
+        ]:
+            self.process_function_definition(node)
            return None

        return self.iterate_children(node.get_children(),
@@ -504,6 +749,18 @@ class CallAnnotationsValidator:
        assert refd is not None

        def_annotations = VlAnnotations.from_nodes_list(node_children)
+        # Implicitly mark definitions in VL_MT_DISABLED_CODE_UNIT .cpp files as
+        # VL_MT_DISABLED. Existence of the annotation on declarations in .h
+        # files is verified below.
+        # Also sets VL_REQUIRES, as this annotation is added together with
+        # explicit VL_MT_DISABLED.
+        if self.is_mt_disabled_code_unit():
+            if node.location.file.name == self._main_source_file:
+                annotations.mt_disabled = True
+                annotations.requires = True
+            if refd.location.file.name == self._main_source_file:
+                def_annotations.mt_disabled = True
+                def_annotations.requires = True

        if not (def_annotations.is_empty() or def_annotations == annotations):
            # Use definition's annotations for the diagnostic
@@ -516,49 +773,67 @@ class CallAnnotationsValidator:
                DiagnosticKind.ANNOTATIONS_DEF_DECL_MISMATCH)

        # Use concatenation of definition and declaration annotations
-        # for callees validation.
+        # for calls validation.
        self._caller = FunctionInfo.from_node(node, refd,
                                              def_annotations | annotations)
+        prev_call_location = self._call_location
        self._call_location = self._caller

+        if self.is_mt_disabled_code_unit():
+            # Report declarations of this functions that don't have MT_DISABLED annotation
+            # and are located in headers.
+            if node.location.file.name == self._main_source_file:
+                usr = node.get_usr()
+                declarations = self._external_decls.get(usr, set())
+                for file, line in declarations:
+                    self.emit_diagnostic(
+                        FunctionInfo.from_decl_file_line_and_refd_node(
+                            file, line, refd, def_annotations),
+                        DiagnosticKind.MISSING_MT_DISABLED_ANNOTATION)
+                if declarations:
+                    del self._external_decls[usr]
+
        self.iterate_children(node_children,
                              self.dispatch_node_inside_definition)

-        self._call_location = None
+        self._call_location = prev_call_location
+        self._caller = prev_call_location

        return None

    # Nodes not located inside definition

    def dispatch_node(self, node: clang.cindex.Cursor):
-        if node.is_definition() and node.kind in [
+        if node.kind in [
                CursorKind.CXX_METHOD, CursorKind.FUNCTION_DECL,
                CursorKind.CONSTRUCTOR, CursorKind.CONVERSION_FUNCTION
        ]:
-            return self.process_function_definition(node)
-        if node.is_definition() and node.kind in [
-                CursorKind.NAMESPACE, CursorKind.STRUCT_DECL,
-                CursorKind.UNION_DECL, CursorKind.CLASS_DECL
-        ]:
-            return self.iterate_children(node.get_children(),
-                                         self.dispatch_node)
+            if node.is_definition():
+                return self.process_function_definition(node)
+            # else:
+            return self.process_function_declaration(node)

        return self.iterate_children(node.get_children(), self.dispatch_node)

    def process_translation_unit(
            self, translation_unit: clang.cindex.TranslationUnit):
        self._level += 1
+        kv_defines = sorted([f"{k}={v}" for k, v in self._defines.items()])
+        concat_defines = '\n'.join(kv_defines)
+        # List of headers already processed in a TU with specified set of defines.
+        tu_processed_headers = self._processed_headers.setdefault(
+            concat_defines, set())
        for child in translation_unit.cursor.get_children():
            if self._is_ignored_top_level(child):
                continue
-            if self._processed_headers:
+            if tu_processed_headers:
                filename = os.path.abspath(child.location.file.name)
-                if filename in self._processed_headers:
+                if filename in tu_processed_headers:
                    continue
            self.dispatch_node(child)
        self._level -= 1

-        self._processed_headers.update([
+        tu_processed_headers.update([
            os.path.abspath(str(hdr.source))
            for hdr in translation_unit.get_includes()
        ])
@@ -620,34 +895,40 @@ def get_filter_funcs(verilator_root: str):


 def precompile_header(compile_command: CompileCommand, tmp_dir: str) -> str:
+    initial_cwd = os.getcwd()
+    errors = []
    try:
-        initial_cwd = os.getcwd()
        os.chdir(compile_command.directory)

        index = Index.create()
        translation_unit = index.parse(compile_command.filename,
                                       compile_command.args)
        for diag in translation_unit.diagnostics:
-            if diag.severity > clang.cindex.Diagnostic.Error:
-                pch_file = None
-                break
-        else:
+            if diag.severity >= clang.cindex.Diagnostic.Error:
+                errors.append(str(diag))
+
+        if len(errors) == 0:
            pch_file = os.path.join(
                tmp_dir,
                f"{compile_command.refid:02}_{os.path.basename(compile_command.filename)}.pch"
            )
            translation_unit.save(pch_file)

+            if pch_file:
+                return pch_file
+
+    except (TranslationUnitSaveError, TranslationUnitLoadError,
+            OSError) as exception:
+        print(f"%Warning: {exception}", file=sys.stderr)
+
+    finally:
        os.chdir(initial_cwd)

-        if pch_file:
-            return pch_file
-
-    except (TranslationUnitSaveError, TranslationUnitLoadError, OSError):
-        pass
-
    print(
-        f"%Warning: Precompiling failed, skipping: {compile_command.filename}")
+        f"%Warning: Precompilation failed, skipping: {compile_command.filename}",
+        file=sys.stderr)
+    for error in errors:
+        print(f"          {error}", file=sys.stderr)
    return ""


@@ -670,7 +951,7 @@ def run_analysis(ccl: Iterable[CompileCommand], pccl: Iterable[CompileCommand],
                                       is_ignored_def, is_ignored_call)
        for compile_command in ccl:
            cav.compile_and_analyze_file(compile_command.filename,
-                                         compile_command.args + extra_args,
+                                         extra_args + compile_command.args,
                                         compile_command.directory)


@@ -788,6 +1069,12 @@ class TopDownSummaryPrinter():
                name += "is mtsafe but calls non-mtsafe function(s)"
            elif func.reason == DiagnosticKind.NON_PURE_CALL_IN_PURE_CTX:
                name += "is pure but calls non-pure function(s)"
+            elif func.reason == DiagnosticKind.NON_STABLE_TREE_CALL_IN_STABLE_TREE_CTX:
+                name += "is stable_tree but calls non-stable_tree or non-mtsafe"
+            elif func.reason == DiagnosticKind.MISSING_MT_DISABLED_ANNOTATION:
+                name += ("defined in a file marked as " +
+                         "VL_MT_DISABLED_CODE_UNIT has declaration(s) " +
+                         "without VL_MT_DISABLED annotation")
            else:
                name += "for unknown reason (please add description)"

@@ -854,10 +1141,15 @@ def main():
                        type=int,
                        default=0,
                        help="Number of parallel jobs to use.")
+    parser.add_argument(
+        "--compile-commands-dir",
+        type=str,
+        default=None,
+        help="Path to directory containing compile_commands.json.")
    parser.add_argument("--cxxflags",
                        type=str,
                        default=None,
-                        help="Flags passed to clang++.")
+                        help="Extra flags passed to clang++.")
    parser.add_argument(
        "--compilation-root",
        type=str,
@@ -882,34 +1174,52 @@ def main():
        cmdline.compilation_root = cmdline.verilator_root

    verilator_root = os.path.abspath(cmdline.verilator_root)
-    compilation_root = os.path.abspath(cmdline.compilation_root)
+    default_compilation_root = os.path.abspath(cmdline.compilation_root)
+
+    compdb: Optional[CompilationDatabase] = None
+    if cmdline.compile_commands_dir:
+        compdb = CompilationDatabase.fromDirectory(
+            cmdline.compile_commands_dir)

-    default_cxx_flags = [
-        f"-I{verilator_root}/src",
-        f"-I{verilator_root}/include",
-        f"-I{verilator_root}/src/obj_opt",
-        "-fcoroutines-ts",
-    ]
    if cmdline.cxxflags is not None:
-        cxxflags = shlex.split(cmdline.cxxflags)
+        common_cxxflags = shlex.split(cmdline.cxxflags)
    else:
-        cxxflags = default_cxx_flags
+        common_cxxflags = []

    precompile_commands_list = []

    if cmdline.precompile:
-        hdr_cxxflags = ['-xc++-header'] + cxxflags
+        hdr_cxxflags = ['-xc++-header'] + common_cxxflags
        for refid, file in enumerate(cmdline.precompile):
            filename = os.path.abspath(file)
            compile_command = CompileCommand(refid, filename, hdr_cxxflags,
-                                             compilation_root)
+                                             default_compilation_root)
            precompile_commands_list.append(compile_command)

    compile_commands_list = []
    for refid, file in enumerate(cmdline.file):
        filename = os.path.abspath(file)
-        compile_command = CompileCommand(refid, filename, cxxflags,
-                                         compilation_root)
+        root = default_compilation_root
+        cxxflags = []
+        if compdb:
+            entry = compdb.getCompileCommands(filename)
+            entry_list = list(entry)
+            # Compilation database can contain multiple entries for single file,
+            # e.g. when it has been updated by appending new entries.
+            # Use last entry for the file, if it exists, as it is the newest one.
+            if len(entry_list) > 0:
+                last_entry = entry_list[-1]
+                root = last_entry.directory
+                entry_args = list(last_entry.arguments)
+                # First argument in compile_commands.json arguments list is
+                # compiler executable name/path. CIndex (libclang) always
+                # implicitly prepends executable name, so it shouldn't be passed
+                # here.
+                cxxflags = common_cxxflags + entry_args[1:]
+        else:
+            cxxflags = common_cxxflags[:]
+
+        compile_command = CompileCommand(refid, filename, cxxflags, root)
        compile_commands_list.append(compile_command)

    summary_printer = TopDownSummaryPrinter()
@@ -1,6 +1,6 @@
 *~
 *.old
-config_build.h
+config_package.h
 Makefile
 Makefile_obj
 .objcache*
@@ -82,6 +82,7 @@ set(HEADERS
    V3File.h
    V3FileLine.h
    V3Force.h
+    V3Fork.h
    V3FunctionTraits.h
    V3Gate.h
    V3Global.h
@@ -150,6 +151,7 @@ set(HEADERS
    V3Table.h
    V3Task.h
    V3ThreadPool.h
+    V3ThreadSafety.h
    V3Timing.h
    V3Trace.h
    V3TraceDecl.h
@@ -227,6 +229,7 @@ set(COMMON_SOURCES
    V3File.cpp
    V3FileLine.cpp
    V3Force.cpp
+    V3Fork.cpp
    V3Gate.cpp
    V3Global.cpp
    V3Graph.cpp
@@ -322,7 +325,7 @@ file(TO_NATIVE_PATH ${srcdir}/../bin/verilator_includer VERILATOR_INCLUDER)
 file(TO_NATIVE_PATH ${srcdir}/vlcovgen VLCOVGEN)
 file(TO_NATIVE_PATH ${srcdir}/config_rev CONFIG_REV)

-configure_file(config_build.h.in config_build.h @ONLY)
+configure_file(config_package.h.in config_package.h @ONLY)

 add_custom_command(
    OUTPUT V3Ast__gen_forward_class_decls.h V3Dfg__gen_forward_class_decls.h
@@ -414,7 +417,7 @@ foreach(astgen_name ${ASTGENERATED_NAMES})
        MAIN_DEPENDENCY ${astgen_name}.cpp
        DEPENDS ${ASTGEN} V3Ast.h
        COMMAND ${PYTHON3} ARGS
-            ${ASTGEN} -I"${srcdir}" --astdef V3AstNodeDType.h --astdef V3AstNodeExpr.h --astdef V3AstNodeOther.h --dfgdef V3DfgVertices.h ${astgen_name}.cpp
+            ${ASTGEN} -I "${srcdir}" --astdef V3AstNodeDType.h --astdef V3AstNodeExpr.h --astdef V3AstNodeOther.h --dfgdef V3DfgVertices.h ${astgen_name}.cpp
    )
    list(APPEND GENERATED_FILES ${astgen_name}__gen.cpp)
 endforeach()
@@ -488,11 +491,13 @@ target_include_directories(${verilator}
 )

 if (WIN32)
+    target_compile_options(${verilator} PRIVATE /bigobj)
    target_compile_definitions(${verilator} PRIVATE
        YY_NO_UNISTD_H
    )
    target_include_directories(${verilator} PRIVATE ../platform/win32)
    target_link_libraries(${verilator} PRIVATE bcrypt psapi)
+    target_link_options(${verilator} PRIVATE /STACK:10000000)
 endif()

 install(TARGETS ${verilator})
@@ -18,14 +18,13 @@
 #### Start of system configuration section. ####

 srcdir = @srcdir@
-PYTHON3 = @PYTHON3@
 EXEEXT = @EXEEXT@
+PYTHON3 = @PYTHON3@
 # VPATH only does sources; fix install_test's not creating ../bin
 vpath %.h @srcdir@

 #### End of system configuration section. ####

-
 default: dbg opt
 debug: dbg
 optimize: opt
@@ -36,6 +35,26 @@ endif

 UNDER_GIT = $(wildcard ${srcdir}/../.git/logs/HEAD)

+ifeq (,$(wildcard obj_dbg/bear.o))
+  ifneq (, $(shell which bear 2>/dev/null))
+    BEAR := $(shell which bear)
+    ifeq (, $(shell $(BEAR) --output obj_dbg/comptest.json -- true))
+      $(shell which bear 2>/dev/null >obj_dbg/bear.o)
+    else
+      # unsupported version
+      BEAR :=
+    endif
+  endif
+else
+  BEAR := $(shell cat obj_dbg/bear.o)
+endif
+
+ifneq ($(BEAR),)
+BEAR_OBJ_OPT := $(BEAR) --append --output obj_dbg/compile_commands.json --
+else
+BEAR_OBJ_OPT :=
+endif
+
 #*********************************************************************

 obj_opt:
@@ -62,8 +81,8 @@ endif

 dbg: ../bin/verilator_bin_dbg$(EXEEXT) ../bin/verilator_coverage_bin_dbg$(EXEEXT)
 ../bin/verilator_bin_dbg$(EXEEXT): obj_dbg ../bin prefiles
-	$(MAKE) -C obj_dbg -j 1  TGT=../$@ VL_DEBUG=1 -f ../Makefile_obj serial
-	$(MAKE) -C obj_dbg       TGT=../$@ VL_DEBUG=1 -f ../Makefile_obj
+	$(BEAR_OBJ_OPT) $(MAKE) -C obj_dbg -j 1  TGT=../$@ VL_DEBUG=1 -f ../Makefile_obj serial
+	$(BEAR_OBJ_OPT) $(MAKE) -C obj_dbg       TGT=../$@ VL_DEBUG=1 -f ../Makefile_obj

 ../bin/verilator_coverage_bin_dbg$(EXEEXT): obj_dbg ../bin prefiles
 	$(MAKE) -C obj_dbg       TGT=../$@ VL_DEBUG=1 VL_VLCOV=1 -f ../Makefile_obj serial_vlcov
@@ -95,7 +114,7 @@ clean mostlyclean distclean maintainer-clean::
 	-rm -f .objcache*

 distclean maintainer-clean::
-	-rm -f Makefile Makefile_obj config_build.h
+	-rm -f Makefile Makefile_obj config_package.h

 maintainer-clean::
 	-rm -f config_rev.h
@@ -92,6 +92,7 @@ endif
 # -lfl not needed as Flex invoked with %nowrap option
 LIBS = $(CFG_LIBS) -lm

+CPPFLAGS += -DVERILATOR_INTERNAL_
 CPPFLAGS += -MMD
 CPPFLAGS += -I. -I$(bldsrc) -I$(srcdir) -I$(incdir) -I../../include
 #CPPFLAGS += -DVL_LEAK_CHECKS  # If running valgrind or other hunting tool
@@ -204,6 +205,7 @@ RAW_OBJS = \
 	V3File.o \
 	V3FileLine.o \
 	V3Force.o \
+	V3Fork.o \
 	V3Gate.o \
 	V3Global.o \
 	V3Graph.o \
@@ -287,6 +289,7 @@ NON_STANDALONE_HEADERS = \
 	V3AstNodeExpr.h  \
 	V3AstNodeOther.h  \
 	V3DfgVertices.h  \
+	V3ThreadPool.h \
 	V3WidthCommit.h  \

 AST_DEFS := \
@@ -47,6 +47,7 @@ VL_DEFINE_DEBUG_FUNCTIONS;
 // Extend V3GraphVertex class for use in latch detection graph

 class LatchDetectGraphVertex final : public V3GraphVertex {
+    VL_RTTI_IMPL(LatchDetectGraphVertex, V3GraphVertex)
 public:
    enum VertexType : uint8_t { VT_BLOCK, VT_BRANCH, VT_OUTPUT };

@@ -54,7 +55,7 @@ private:
    const string m_name;  // Only used for .dot file generation
    const VertexType m_type;  // Vertex type (BLOCK/BRANCH/OUTPUT)

-    string typestr() const {  //   "
+    string typestr() const VL_MT_SAFE {  //   "
        switch (m_type) {
        case VT_BLOCK: return "(||)";  // basic block node
        case VT_BRANCH: return "(&&)";  // if/else branch mode
@@ -68,7 +69,7 @@ public:
        : V3GraphVertex{graphp}
        , m_name{name}
        , m_type{type} {}
-    string name() const override { return m_name + " " + typestr(); }
+    string name() const override VL_MT_STABLE { return m_name + " " + typestr(); }
    string dotColor() const override { return user() ? "green" : "black"; }
    virtual int type() const { return m_type; }
 };
@@ -183,7 +184,7 @@ public:
                        << " (not all control paths of combinational always assign a value)\n"
                        << nodep->warnMore()
                        << "... Suggest use of always_latch for intentional latches");
-                if (dumpGraph() >= 9) dumpDotFilePrefixed("latch_" + vrp->name());
+                if (dumpGraphLevel() >= 9) dumpDotFilePrefixed("latch_" + vrp->name());
            }
            vertp->user(false);  // Clear again (see above)
            vrp->varp()->isLatched(latch_detected);
@@ -309,7 +310,7 @@ AstActive*& ActiveNamer::getSpecialActive<AstSenItem::Combo>() {
 //######################################################################
 // Latch checking visitor

-class ActiveLatchCheckVisitor final : public VNVisitor {
+class ActiveLatchCheckVisitor final : public VNVisitorConst {
 private:
    // NODE STATE
    // Input:
@@ -320,7 +321,8 @@ private:
    // VISITORS
    void visit(AstVarRef* nodep) override {
        const AstVar* const varp = nodep->varp();
-        if (nodep->access().isWriteOrRW() && varp->isSignal() && !varp->isUsedLoopIdx()) {
+        if (nodep->access().isWriteOrRW() && varp->isSignal() && !varp->isUsedLoopIdx()
+            && !varp->isFuncLocalSticky()) {
            m_graph.addAssignment(nodep);
        }
    }
@@ -329,20 +331,22 @@ private:
            LatchDetectGraphVertex* const parentp = m_graph.currentp();
            LatchDetectGraphVertex* const branchp = m_graph.addPathVertex(parentp, "BRANCH", true);
            m_graph.addPathVertex(branchp, "IF");
-            iterateAndNextNull(nodep->thensp());
+            iterateAndNextConstNull(nodep->thensp());
            m_graph.addPathVertex(branchp, "ELSE");
-            iterateAndNextNull(nodep->elsesp());
+            iterateAndNextConstNull(nodep->elsesp());
            m_graph.currentp(parentp);
+        } else {
+            iterateChildrenConst(nodep);
        }
    }
    //--------------------
-    void visit(AstNode* nodep) override { iterateChildren(nodep); }
+    void visit(AstNode* nodep) override { iterateChildrenConst(nodep); }

 public:
    // CONSTRUCTORS
    ActiveLatchCheckVisitor(AstNode* nodep, bool expectLatch) {
        m_graph.begin();
-        iterate(nodep);
+        iterateConst(nodep);
        m_graph.latchCheck(nodep, expectLatch);
    }
    ~ActiveLatchCheckVisitor() override = default;
@@ -652,5 +656,5 @@ public:
 void V3Active::activeAll(AstNetlist* nodep) {
    UINFO(2, __FUNCTION__ << ": " << endl);
    { ActiveVisitor{nodep}; }  // Destruct before checking
-    V3Global::dumpCheckGlobalTree("active", 0, dumpTree() >= 3);
+    V3Global::dumpCheckGlobalTree("active", 0, dumpTreeLevel() >= 3);
 }
@@ -145,5 +145,5 @@ public:
 void V3ActiveTop::activeTopAll(AstNetlist* nodep) {
    UINFO(2, __FUNCTION__ << ": " << endl);
    { ActiveTopVisitor{nodep}; }  // Destruct before checking
-    V3Global::dumpCheckGlobalTree("activetop", 0, dumpTree() >= 3);
+    V3Global::dumpCheckGlobalTree("activetop", 0, dumpTreeLevel() >= 3);
 }
@@ -20,6 +20,7 @@
 #include "V3Assert.h"

 #include "V3Ast.h"
+#include "V3Error.h"
 #include "V3Global.h"
 #include "V3Stats.h"

@@ -51,14 +52,22 @@ private:
    bool m_inSampled = false;  // True inside a sampled expression

    // METHODS
-    string assertDisplayMessage(AstNode* nodep, const string& prefix, const string& message) {
-        return (string("[%0t] " + prefix + ": ") + nodep->fileline()->filebasename() + ":"
-                + cvtToStr(nodep->fileline()->lineno()) + ": Assertion failed in %m"
-                + ((message != "") ? ": " : "") + message + "\n");
+    string assertDisplayMessage(AstNode* nodep, const string& prefix, const string& message,
+                                VDisplayType severity) {
+        if (severity == VDisplayType::DT_ERROR || severity == VDisplayType::DT_FATAL) {
+            return (string{"[%0t] " + prefix + ": "} + nodep->fileline()->filebasename() + ":"
+                    + cvtToStr(nodep->fileline()->lineno()) + ": Assertion failed in %m"
+                    + ((message != "") ? ": " : "") + message + "\n");
+        } else {
+            return (string{"[%0t] " + prefix + ": "} + nodep->fileline()->filebasename() + ":"
+                    + cvtToStr(nodep->fileline()->lineno()) + ": %m"
+                    + ((message != "") ? ": " : "") + message + "\n");
+        }
    }
    void replaceDisplay(AstDisplay* nodep, const string& prefix) {
+        nodep->fmtp()->text(
+            assertDisplayMessage(nodep, prefix, nodep->fmtp()->text(), nodep->displayType()));
        nodep->displayType(VDisplayType::DT_WRITE);
-        nodep->fmtp()->text(assertDisplayMessage(nodep, prefix, nodep->fmtp()->text()));
        // cppcheck-suppress nullPointer
        AstNodeExpr* const timenewp = new AstTime{nodep->fileline(), m_modp->timeunit()};
        if (AstNodeExpr* const timesp = nodep->fmtp()->exprsp()) {
@@ -148,7 +157,7 @@ private:
            sentreep->unlinkFrBack();
            if (m_procedurep) {
                // To support this need queue of asserts to activate
-                nodep->v3error("Unsupported: Procedural concurent assertion with"
+                nodep->v3error("Unsupported: Procedural concurrent assertion with"
                               " clocking event inside always (IEEE 1800-2917 16.14.6)");
            }
        }
@@ -182,7 +191,7 @@ private:
            const bool force = VN_IS(nodep, AssertIntrinsic);
            if (passsp) passsp = newIfAssertOn(passsp, force);
            if (failsp) failsp = newIfAssertOn(failsp, force);
-            if (!failsp) failsp = newFireAssertUnchecked(nodep, "'assert' failed.");
+            if (!passsp && !failsp) failsp = newFireAssertUnchecked(nodep, "'assert' failed.");
            ifp = new AstIf{nodep->fileline(), propp, passsp, failsp};
            ifp->isBoundsCheck(true);  // To avoid LATCH warning
            // It's more LIKELY that we'll take the nullptr if clause
@@ -247,7 +256,7 @@ private:
                ifp = nextifp;
            } while (ifp);

-            AstNode* const newifp = nodep->cloneTree(false);
+            AstIf* const newifp = nodep->cloneTree(false);
            const bool allow_none = nodep->unique0Pragma();

            // Empty case means no property
@@ -419,9 +428,10 @@ private:
            replaceDisplay(nodep, "-Info");
        } else if (nodep->displayType() == VDisplayType::DT_WARNING) {
            replaceDisplay(nodep, "%%Warning");
-        } else if (nodep->displayType() == VDisplayType::DT_ERROR
-                   || nodep->displayType() == VDisplayType::DT_FATAL) {
+        } else if (nodep->displayType() == VDisplayType::DT_ERROR) {
            replaceDisplay(nodep, "%%Error");
+        } else if (nodep->displayType() == VDisplayType::DT_FATAL) {
+            replaceDisplay(nodep, "%%Fatal");
        } else if (nodep->displayType() == VDisplayType::DT_MONITOR) {
            nodep->displayType(VDisplayType::DT_DISPLAY);
            const auto fl = nodep->fileline();
@@ -535,5 +545,5 @@ public:
 void V3Assert::assertAll(AstNetlist* nodep) {
    UINFO(2, __FUNCTION__ << ": " << endl);
    { AssertVisitor{nodep}; }  // Destruct before checking
-    V3Global::dumpCheckGlobalTree("assert", 0, dumpTree() >= 3);
+    V3Global::dumpCheckGlobalTree("assert", 0, dumpTreeLevel() >= 3);
 }
@@ -21,7 +21,6 @@
 #include "verilatedos.h"

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

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

@@ -229,7 +229,7 @@ private:
                //     always queue.push(<sampled var>);
                AstCMethodHard* const pushp = new AstCMethodHard{
                    flp, new AstVarRef{flp, queueVarp, VAccess::WRITE}, "push",
-                    new AstTime(nodep->fileline(), m_modp->timeunit())};
+                    new AstTime{nodep->fileline(), m_modp->timeunit()}};
                pushp->addPinsp(exprp->cloneTree(false));
                pushp->dtypeSetVoid();
                m_clockingp->addNextHere(
@@ -238,7 +238,7 @@ private:
                //     always @<clocking event> queue.pop(<skew>, /*out*/<skewed var>});
                AstCMethodHard* const popp = new AstCMethodHard{
                    flp, new AstVarRef{flp, queueVarp, VAccess::READWRITE}, "pop",
-                    new AstTime(nodep->fileline(), m_modp->timeunit())};
+                    new AstTime{nodep->fileline(), m_modp->timeunit()}};
                popp->addPinsp(skewp->unlinkFrBack());
                popp->addPinsp(refp);
                popp->dtypeSetVoid();
@@ -496,5 +496,5 @@ public:
 void V3AssertPre::assertPreAll(AstNetlist* nodep) {
    UINFO(2, __FUNCTION__ << ": " << endl);
    { AssertPreVisitor{nodep}; }  // Destruct before checking
-    V3Global::dumpCheckGlobalTree("assertpre", 0, dumpTree() >= 3);
+    V3Global::dumpCheckGlobalTree("assertpre", 0, dumpTreeLevel() >= 3);
 }
@@ -55,12 +55,28 @@ bool VNUser5InUse::s_userBusy = false;
 int AstNodeDType::s_uniqueNum = 0;

 //######################################################################
-// V3AstType
+// VNType
+
+const VNTypeInfo VNType::typeInfoTable[] = {
+#include "V3Ast__gen_type_info.h"  // From ./astgen
+};

 std::ostream& operator<<(std::ostream& os, VNType rhs);

 //######################################################################
-// Creators
+// VSelfPointerText
+
+const std::shared_ptr<const string> VSelfPointerText::s_emptyp = std::make_shared<string>("");
+const std::shared_ptr<const string> VSelfPointerText::s_thisp = std::make_shared<string>("this");
+
+string VSelfPointerText::protect(bool useSelfForThis, bool protect) const {
+    const string& sp
+        = useSelfForThis ? VString::replaceWord(asString(), "this", "vlSelf") : asString();
+    return VIdProtect::protectWordsIf(sp, protect);
+}
+
+//######################################################################
+// AstNode

 AstNode::AstNode(VNType t, FileLine* fl)
    : m_type{t}
@@ -155,7 +171,7 @@ string AstNode::vcdName(const string& namein) {
    return prettyName(pretty);
 }

-string AstNode::prettyName(const string& namein) {
+string AstNode::prettyName(const string& namein) VL_PURE {
    // This function is somewhat hot, so we short-circuit some compares
    string pretty;
    pretty.reserve(namein.length());
@@ -296,17 +312,19 @@ void AstNode::debugTreeChange(const AstNode* nodep, const char* prefix, int line
 // Called on all major tree changers.
 // Only for use for those really nasty bugs relating to internals
 // Note this may be null.
-// if (debug()) cout<<"-treeChange: V3Ast.cpp:"<<lineno<<" Tree Change for "
-//                 <<prefix<<": "<<cvtToHex(this)<<" <e"<<AstNode::s_editCntGbl<<">"<<endl;
+// if (debug() && nodep) cout << "-treeChange: V3Ast.cpp:" << lineno
+//          << " Tree Change for " << prefix << ": "
+//          << cvtToHex(nodep) << " <e" << AstNode::s_editCntGbl << ">"
+//          << "m_iterpp=" << (void*)nodep->m_iterpp << endl;
 // if (debug()) {
 //  cout<<"-treeChange: V3Ast.cpp:"<<lineno<<" Tree Change for "<<prefix<<endl;
 //  // Commenting out the section below may crash, as the tree state
 //  // between edits is not always consistent for printing
 //  cout<<"-treeChange: V3Ast.cpp:"<<lineno<<" Tree Change for "<<prefix<<endl;
 //  v3Global.rootp()->dumpTree("-  treeChange: ");
-//  if (next||1) this->dumpTreeAndNext(cout, prefix);
-//  else this->dumpTree(prefix);
-//  this->checkTree();
+//  if (next||1) nodep->dumpTreeAndNext(cout, prefix);
+//  else nodep->dumpTree(prefix);
+//  nodep->checkTree();
 //  v3Global.rootp()->checkTree();
 //}
 #endif
@@ -345,7 +363,8 @@ AstNode* AstNode::addNext<AstNode, AstNode>(AstNode* nodep, AstNode* newp) {
        newtailp->m_headtailp = headp;
        headp->m_headtailp = newtailp;
        newp->editCountInc();
-        if (oldtailp->m_iterpp) *(oldtailp->m_iterpp) = newp;  // Iterate on new item
+        // No change of m_iterpp, as only changing m_nextp of current node;
+        // the current node is still the one at the iteration point
    }
    debugTreeChange(nodep, "-addNextOut:", __LINE__, true);
    return nodep;
@@ -395,7 +414,8 @@ void AstNode::addNextHere(AstNode* newp) {
        }  // else is head, and we're inserting into the middle, so no other change
    }

-    if (this->m_iterpp) *(this->m_iterpp) = newp;  // Iterate on new item
+    // No change of m_iterpp, as adding after current node;
+    // the current node is still the one at the iteration point
    debugTreeChange(this, "-addHereOut: ", __LINE__, true);
 }

@@ -563,8 +583,10 @@ AstNode* AstNode::unlinkFrBackWithNext(VNRelinker* linkerp) {
    // Relink
    oldp->m_backp = nullptr;
    // Iterator fixup
-    if (oldp->m_iterpp) *(oldp->m_iterpp) = nullptr;
-    oldp->m_iterpp = nullptr;
+    if (oldp->m_iterpp) {
+        *(oldp->m_iterpp) = nullptr;
+        oldp->m_iterpp = nullptr;
+    }
    debugTreeChange(oldp, "-unlinkWNextOut: ", __LINE__, true);
    return oldp;
 }
@@ -578,7 +600,11 @@ AstNode* AstNode::unlinkFrBack(VNRelinker* linkerp) {
    if (linkerp) {
        linkerp->m_oldp = oldp;
        linkerp->m_backp = backp;
-        linkerp->m_iterpp = oldp->m_iterpp;
+        if (oldp->m_iterpp) {  // Assumes we will always relink() if want to keep iterating
+            linkerp->m_iterpp = oldp->m_iterpp;
+            *(oldp->m_iterpp) = nullptr;
+            oldp->m_iterpp = nullptr;
+        }
        if (backp->m_nextp == oldp) {
            linkerp->m_chg = VNRelinker::RELINK_NEXT;
        } else if (backp->m_op1p == oldp) {
@@ -623,12 +649,15 @@ AstNode* AstNode::unlinkFrBack(VNRelinker* linkerp) {
        }
    }
    // Iterator fixup
-    if (oldp->m_iterpp) *(oldp->m_iterpp) = oldp->m_nextp;
+    if (oldp->m_iterpp) {  // Only if no linker, point to next in list
+        if (oldp->m_nextp) oldp->m_nextp->m_iterpp = oldp->m_iterpp;
+        *(oldp->m_iterpp) = oldp->m_nextp;
+        oldp->m_iterpp = nullptr;
+    }
    // Relink
    oldp->m_nextp = nullptr;
    oldp->m_backp = nullptr;
-    oldp->m_headtailp = this;
-    oldp->m_iterpp = nullptr;
+    oldp->m_headtailp = oldp;
    debugTreeChange(oldp, "-unlinkFrBkOut: ", __LINE__, true);
    return oldp;
 }
@@ -666,12 +695,12 @@ void AstNode::relink(VNRelinker* linkerp) {
    // Iterator fixup
    if (linkerp->m_iterpp) {
        // If we're iterating over a next() link, we need to follow links off the
-        // NEW node.  Thus we pass iteration information via a pointer in the node.
+        // NEW node, which is always assumed to be what we are relinking to.
        // This adds a unfortunate hot 8 bytes to every AstNode, but is faster than passing
        // across every function.
        // If anyone has a cleaner way, I'd be grateful.
-        *(linkerp->m_iterpp) = newp;
        newp->m_iterpp = linkerp->m_iterpp;
+        *(newp->m_iterpp) = newp;
    }
    // Empty the linker so not used twice accidentally
    linkerp->m_backp = nullptr;
@@ -833,6 +862,7 @@ void AstNode::deleteNode() {
    this->m_op2p = reinterpret_cast<AstNode*>(0x1);
    this->m_op3p = reinterpret_cast<AstNode*>(0x1);
    this->m_op4p = reinterpret_cast<AstNode*>(0x1);
+    this->m_iterpp = reinterpret_cast<AstNode**>(0x1);
    if (
 #if !defined(VL_DEBUG) || defined(VL_LEAK_CHECKS)
        true
@@ -907,7 +937,7 @@ void AstNode::iterateChildren(VNVisitor& v) {
    if (m_op4p) m_op4p->iterateAndNext(v);
 }

-void AstNode::iterateChildrenConst(VNVisitor& v) {
+void AstNode::iterateChildrenConst(VNVisitorConst& v) {
    // This is a very hot function
    ASTNODE_PREFETCH(m_op1p);
    ASTNODE_PREFETCH(m_op2p);
@@ -948,13 +978,13 @@ void AstNode::iterateAndNext(VNVisitor& v) {
        niterp->m_iterpp = nullptr;
        if (VL_UNLIKELY(niterp != nodep)) {  // Edited node inside accept
            nodep = niterp;
-        } else {  // Unchanged node, just continue loop
+        } else {  // Unchanged node (though maybe updated m_next), just continue loop
            nodep = niterp->m_nextp;
        }
    }
 }

-void AstNode::iterateListBackwards(VNVisitor& v) {
+void AstNode::iterateListBackwardsConst(VNVisitorConst& v) {
    AstNode* nodep = this;
    while (nodep->m_nextp) nodep = nodep->m_nextp;
    while (nodep) {
@@ -968,14 +998,14 @@ void AstNode::iterateListBackwards(VNVisitor& v) {
    }
 }

-void AstNode::iterateChildrenBackwards(VNVisitor& v) {
-    if (m_op1p) m_op1p->iterateListBackwards(v);
-    if (m_op2p) m_op2p->iterateListBackwards(v);
-    if (m_op3p) m_op3p->iterateListBackwards(v);
-    if (m_op4p) m_op4p->iterateListBackwards(v);
+void AstNode::iterateChildrenBackwardsConst(VNVisitorConst& v) {
+    if (m_op1p) m_op1p->iterateListBackwardsConst(v);
+    if (m_op2p) m_op2p->iterateListBackwardsConst(v);
+    if (m_op3p) m_op3p->iterateListBackwardsConst(v);
+    if (m_op4p) m_op4p->iterateListBackwardsConst(v);
 }

-void AstNode::iterateAndNextConst(VNVisitor& v) {
+void AstNode::iterateAndNextConst(VNVisitorConst& v) {
    // Keep following the current list even if edits change it
    AstNode* nodep = this;
    do {
@@ -1065,10 +1095,12 @@ bool AstNode::sameTreeIter(const AstNode* node1p, const AstNode* node2p, bool ig
    // private: Return true if the two trees are identical
    if (!node1p && !node2p) return true;
    if (!node1p || !node2p) return false;
-    if (node1p->type() != node2p->type() || node1p->dtypep() != node2p->dtypep()
-        || !node1p->same(node2p) || (gateOnly && !node1p->isGateOptimizable())) {
-        return false;
-    }
+    if (node1p->type() != node2p->type()) return false;
+    UASSERT_OBJ(
+        (!node1p->dtypep() && !node2p->dtypep()) || (node1p->dtypep() && node2p->dtypep()), node1p,
+        "Comparison of a node with dtypep() with a node without dtypep()\n-node2=" << node2p);
+    if (node1p->dtypep() && !node1p->dtypep()->similarDType(node2p->dtypep())) return false;
+    if (!node1p->same(node2p) || (gateOnly && !node1p->isGateOptimizable())) return false;
    return (sameTreeIter(node1p->m_op1p, node2p->m_op1p, false, gateOnly)
            && sameTreeIter(node1p->m_op2p, node2p->m_op2p, false, gateOnly)
            && sameTreeIter(node1p->m_op3p, node2p->m_op3p, false, gateOnly)
@@ -1079,12 +1111,60 @@ bool AstNode::sameTreeIter(const AstNode* node1p, const AstNode* node2p, bool ig
 //======================================================================
 // Debugging

-void AstNode::checkTreeIter(const AstNode* prevBackp) const {
+void AstNode::checkTreeIter(const AstNode* prevBackp) const VL_MT_STABLE {
    // private: Check a tree and children
    UASSERT_OBJ(prevBackp == this->backp(), this, "Back node inconsistent");
-    switch (this->type()) {
-#include "V3Ast__gen_op_checks.h"
-    default: VL_UNREACHABLE;  // LCOV_EXCL_LINE
+    const VNTypeInfo& typeInfo = *type().typeInfo();
+    for (int i = 1; i <= 4; i++) {
+        AstNode* nodep = nullptr;
+        switch (i) {
+        case 1: nodep = op1p(); break;
+        case 2: nodep = op2p(); break;
+        case 3: nodep = op3p(); break;
+        case 4: nodep = op4p(); break;
+        default: this->v3fatalSrc("Bad case"); break;
+        }
+        const char* opName = typeInfo.m_opNamep[i - 1];
+        switch (typeInfo.m_opType[i - 1]) {
+        case VNTypeInfo::OP_UNUSED:
+            UASSERT_OBJ(!nodep, this, typeInfo.m_namep << " must not use " << opName << "()");
+            break;
+        case VNTypeInfo::OP_USED:
+            UASSERT_OBJ(nodep, this,
+                        typeInfo.m_namep << " must have non nullptr " << opName << "()");
+            UASSERT_OBJ(!nodep->nextp(), this,
+                        typeInfo.m_namep << "::" << opName
+                                         << "() cannot have a non nullptr nextp()");
+            nodep->checkTreeIter(this);
+            break;
+        case VNTypeInfo::OP_LIST:
+            if (const AstNode* const headp = nodep) {
+                const AstNode* backp = this;
+                const AstNode* tailp = headp;
+                const AstNode* opp = headp;
+                do {
+                    opp->checkTreeIter(backp);
+                    UASSERT_OBJ(opp == headp || !opp->nextp() || !opp->m_headtailp, opp,
+                                "Headtailp should be null in middle of lists");
+                    backp = tailp = opp;
+                    opp = opp->nextp();
+                } while (opp);
+                UASSERT_OBJ(headp->m_headtailp == tailp, headp,
+                            "Tail in headtailp is inconsistent");
+                UASSERT_OBJ(tailp->m_headtailp == headp, tailp,
+                            "Head in headtailp is inconsistent");
+            }
+            break;
+        case VNTypeInfo::OP_OPTIONAL:
+            if (nodep) {
+                UASSERT_OBJ(!nodep->nextp(), this,
+                            typeInfo.m_namep << "::" << opName
+                                             << "() cannot have a non-nullptr nextp()");
+                nodep->checkTreeIter(this);
+            }
+            break;
+        default: this->v3fatalSrc("Bad case"); break;
+        }
    }
 }

@@ -1129,7 +1209,7 @@ void AstNode::checkIter() const {
    if (m_iterpp) {
        dumpPtrs(cout);
        // Perhaps something forgot to clear m_iterpp?
-        this->v3fatalSrc("Iteration link should be nullptr");
+        this->v3fatalSrc("Iteration link m_iterpp should be nullptr");
    }
 }

@@ -1201,7 +1281,7 @@ 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() && ::dumpTree() < 9) {
+            if (editCountGbl() == editCountLast() && ::dumpTreeLevel() < 9) {
                *logsp << '\n';
                *logsp << "No changes since last dump!\n";
            } else {
@@ -1211,7 +1291,7 @@ 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() || ::dumpTree())) {
+    if (doCheck && (v3Global.opt.debugCheck() || ::dumpTreeLevel())) {
        // Error check
        checkTree();
        // Broken isn't part of check tree because it can munge iterp's
@@ -1273,12 +1353,6 @@ bool AstNode::isTreePureRecurse() const {
    return true;
 }

-void AstNode::v3errorEndFatal(std::ostringstream& str) const VL_REQUIRES(V3Error::s().m_mutex) {
-    v3errorEnd(str);
-    assert(0);  // LCOV_EXCL_LINE
-    VL_UNREACHABLE;
-}
-
 string AstNode::instanceStr() const {
    // Max iterations before giving up on location search,
    // in case we have some circular reference bug.
@@ -1303,9 +1377,9 @@ string AstNode::instanceStr() const {

    return "";
 }
-void AstNode::v3errorEnd(std::ostringstream& str) const VL_REQUIRES(V3Error::s().m_mutex) {
+void AstNode::v3errorEnd(std::ostringstream& str) const VL_RELEASE(V3Error::s().m_mutex) {
    if (!m_fileline) {
-        V3Error::s().v3errorEnd(str, instanceStr());
+        V3Error::v3errorEnd(str, instanceStr());
    } else {
        std::ostringstream nsstr;
        nsstr << str.str();
@@ -1322,6 +1396,11 @@ void AstNode::v3errorEnd(std::ostringstream& str) const VL_REQUIRES(V3Error::s()
            nsstr, m_fileline->warnIsOff(V3Error::s().errorCode()) ? "" : instanceStr());
    }
 }
+void AstNode::v3errorEndFatal(std::ostringstream& str) const VL_RELEASE(V3Error::s().m_mutex) {
+    v3errorEnd(str);
+    assert(0);  // LCOV_EXCL_LINE
+    VL_UNREACHABLE;
+}

 //======================================================================
 // Data type conversion
@@ -1342,7 +1421,9 @@ void AstNode::dtypeChgWidthSigned(int width, int widthMin, VSigning numeric) {
        dtypeSetLogicUnsized(width, widthMin, numeric);
    } else {
        if (width == dtypep()->width() && widthMin == dtypep()->widthMin()
-            && numeric == dtypep()->numeric())
+            && numeric == dtypep()->numeric()
+            // Enums need to become direct sizes to avoid later ENUMVALUE errors
+            && !VN_IS(dtypep()->skipRefToEnump(), EnumDType))
            return;  // Correct already
        // FUTURE: We may be pointing at a two state data type, and this may
        // convert it to logic.  Since the AstVar remains correct, we
@@ -1388,6 +1469,9 @@ AstNodeDType* AstNode::findQueueIndexDType() const {
 AstNodeDType* AstNode::findVoidDType() const {
    return v3Global.rootp()->typeTablep()->findVoidDType(fileline());
 }
+AstNodeDType* AstNode::findStreamDType() const {
+    return v3Global.rootp()->typeTablep()->findStreamDType(fileline());
+}

 //######################################################################
 // VNDeleter
@@ -82,12 +82,36 @@ using MTaskIdSet = std::set<int>;  // Set of mtaskIds for Var sorting
 // Ast<nodetypename>*' is returned.
 #define VN_AS(nodep, nodetypename) (AstNode::privateAs<Ast##nodetypename, decltype(nodep)>(nodep))

+// Same as VN_AS, but only checks the type in debug builds. Type checking is less critical in node
+// child getters (the strongly-typed functions that wrap op*p pointers). This is because the op*p
+// pointers are usually populated by code that already asserts the correct type. Having fewer type
+// assertions yields better performance in release builds.
+#ifdef VL_DEBUG
+#define VN_DBG_AS(nodep, nodetypename) VN_AS(nodep, nodetypename)
+#else
+#define VN_DBG_AS(nodep, nodetypename) \
+    (AstNode::unsafePrivateAs<Ast##nodetypename, decltype(nodep)>(nodep))
+#endif
+
 // (V)erilator (N)ode deleted: Pointer to deleted AstNode (for assertions only)
 #define VN_DELETED(nodep) VL_UNLIKELY((uint64_t)(nodep) == 0x1)

 //######################################################################

+struct VNTypeInfo {
+    const char* m_namep;
+    enum uint8_t {
+        OP_UNUSED,
+        OP_USED,
+        OP_LIST,
+        OP_OPTIONAL,
+    } m_opType[4];
+    const char* m_opNamep[4];
+};
+
 class VNType final {
+    static const VNTypeInfo typeInfoTable[];
+
 public:
 #include "V3Ast__gen_type_enum.h"  // From ./astgen
    // Above include has:
@@ -100,13 +124,14 @@ public:
    constexpr VNType(en _e) VL_MT_SAFE : m_e{_e} {}
    explicit VNType(int _e)
        : m_e(static_cast<en>(_e)) {}  // Need () or GCC 4.8 false warning
+    const VNTypeInfo* typeInfo() const VL_MT_SAFE { return &typeInfoTable[m_e]; }
    constexpr operator en() const VL_MT_SAFE { return m_e; }
 };
-constexpr bool operator==(const VNType& lhs, const VNType& rhs) VL_MT_SAFE {
+constexpr bool operator==(const VNType& lhs, const VNType& rhs) VL_PURE {
    return lhs.m_e == rhs.m_e;
 }
-constexpr bool operator==(const VNType& lhs, VNType::en rhs) { return lhs.m_e == rhs; }
-constexpr bool operator==(VNType::en lhs, const VNType& rhs) { return lhs == rhs.m_e; }
+constexpr bool operator==(const VNType& lhs, VNType::en rhs) VL_PURE { return lhs.m_e == rhs; }
+constexpr bool operator==(VNType::en lhs, const VNType& rhs) VL_PURE { return lhs == rhs.m_e; }
 inline std::ostream& operator<<(std::ostream& os, const VNType& rhs) { return os << rhs.ascii(); }

 // ######################################################################
@@ -461,6 +486,7 @@ public:
        TRIGGER_SCHEDULER,
        DYNAMIC_TRIGGER_SCHEDULER,
        FORK_SYNC,
+        PROCESS_REFERENCE,
        // Unsigned and two state; fundamental types
        UINT32,
        UINT64,
@@ -470,7 +496,7 @@ public:
        _ENUM_MAX
    };
    enum en m_e;
-    const char* ascii() const {
+    const char* ascii() const VL_MT_SAFE {
        static const char* const names[] = {"%E-unk",
                                            "bit",
                                            "byte",
@@ -493,6 +519,7 @@ public:
                                            "VlTriggerScheduler",
                                            "VlDynamicTriggerScheduler",
                                            "VlFork",
+                                            "VlProcessRef",
                                            "IData",
                                            "QData",
                                            "LOGIC_IMPLICIT",
@@ -500,13 +527,20 @@ public:
        return names[m_e];
    }
    const char* dpiType() const {
-        static const char* const names[]
-            = {"%E-unk",       "svBit",         "char",          "void*",        "char",
-               "int",          "%E-integer",    "svLogic",       "long long",    "double",
-               "short",        "%E-time",       "const char*",   "%E-untyped",   "dpiScope",
-               "const char*",  "%E-mtaskstate", "%E-triggervec", "%E-dly-sched", "%E-trig-sched",
-               "%E-dyn-sched", "%E-fork",       "IData",         "QData",        "%E-logic-implct",
-               " MAX"};
+        static const char* const names[] = {"%E-unk",        "svBit",
+                                            "char",          "void*",
+                                            "char",          "int",
+                                            "%E-integer",    "svLogic",
+                                            "long long",     "double",
+                                            "short",         "%E-time",
+                                            "const char*",   "%E-untyped",
+                                            "dpiScope",      "const char*",
+                                            "%E-mtaskstate", "%E-triggervec",
+                                            "%E-dly-sched",  "%E-trig-sched",
+                                            "%E-dyn-sched",  "%E-fork",
+                                            "%E-proc-ref",   "IData",
+                                            "QData",         "%E-logic-implct",
+                                            " MAX"};
        return names[m_e];
    }
    static void selfTest() {
@@ -545,6 +579,7 @@ public:
        case TRIGGER_SCHEDULER: return 0;  // opaque
        case DYNAMIC_TRIGGER_SCHEDULER: return 0;  // opaque
        case FORK_SYNC: return 0;  // opaque
+        case PROCESS_REFERENCE: return 0;  // opaque
        case UINT32: return 32;
        case UINT64: return 64;
        default: return 0;
@@ -584,7 +619,7 @@ public:
        return (m_e == EVENT || m_e == STRING || m_e == SCOPEPTR || m_e == CHARPTR
                || m_e == MTASKSTATE || m_e == TRIGGERVEC || m_e == DELAY_SCHEDULER
                || m_e == TRIGGER_SCHEDULER || m_e == DYNAMIC_TRIGGER_SCHEDULER || m_e == FORK_SYNC
-                || m_e == DOUBLE || m_e == UNTYPED);
+                || m_e == PROCESS_REFERENCE || m_e == DOUBLE || m_e == UNTYPED);
    }
    bool isDouble() const VL_MT_SAFE { return m_e == DOUBLE; }
    bool isEvent() const { return m_e == EVENT; }
@@ -781,6 +816,7 @@ public:
            "BLOCKTEMP", "MODULETEMP", "STMTTEMP",     "XTEMP",   "IFACEREF", "MEMBER"};
        return names[m_e];
    }
+    bool isParam() const { return m_e == GPARAM || m_e == LPARAM; }
    bool isSignal() const {
        return (m_e == WIRE || m_e == WREAL || m_e == IMPLICITWIRE || m_e == TRIWIRE || m_e == TRI0
                || m_e == TRI1 || m_e == PORT || m_e == SUPPLY0 || m_e == SUPPLY1 || m_e == VAR);
@@ -1097,21 +1133,21 @@ public:
    }
    //
    VNumRange() = default;
-    VNumRange(int hi, int lo, bool littleEndian) { init(hi, lo, littleEndian); }
+    VNumRange(int hi, int lo, bool ascending) { init(hi, lo, ascending); }
    VNumRange(int left, int right)
        : m_left{left}
        , m_right{right}
        , m_ranged{true} {}
    ~VNumRange() = default;
    // MEMBERS
-    void init(int hi, int lo, bool littleEndian) {
+    void init(int hi, int lo, bool ascending) {
        if (lo > hi) {
            const int t = hi;
            hi = lo;
            lo = t;
        }
-        m_left = littleEndian ? lo : hi;
-        m_right = littleEndian ? hi : lo;
+        m_left = ascending ? lo : hi;
+        m_right = ascending ? hi : lo;
        m_ranged = true;
    }
    int left() const { return m_left; }
@@ -1122,10 +1158,10 @@ public:
    int lo() const VL_MT_SAFE {
        return m_left > m_right ? m_right : m_left;
    }  // How to show a declaration
-    int leftToRightInc() const { return littleEndian() ? 1 : -1; }
+    int leftToRightInc() const { return ascending() ? 1 : -1; }
    int elements() const VL_MT_SAFE { return hi() - lo() + 1; }
    bool ranged() const { return m_ranged; }
-    bool littleEndian() const { return m_left < m_right; }
+    bool ascending() const { return m_left < m_right; }
    int hiMaxSelect() const {
        return (lo() < 0 ? hi() - lo() : hi());
    }  // Maximum value a [] select may index
@@ -1147,30 +1183,34 @@ inline std::ostream& operator<<(std::ostream& os, const VNumRange& rhs) {
 class VUseType final {
 public:
    enum en : uint8_t {
-        IMP_INCLUDE,  // Implementation (.cpp) needs an include
-        INT_INCLUDE,  // Interface (.h) needs an include
-        IMP_FWD_CLASS,  // Implementation (.cpp) needs a forward class declaration
-        INT_FWD_CLASS,  // Interface (.h) needs a forward class declaration
+        // Enum values are compared with <, so order matters
+        INT_FWD_CLASS = 1 << 0,  // Interface (.h) needs a forward class declaration
+        INT_INCLUDE = 1 << 1,  // Interface (.h) needs an include
    };
    enum en m_e;
    VUseType()
-        : m_e{IMP_FWD_CLASS} {}
+        : m_e{INT_FWD_CLASS} {}
    // cppcheck-suppress noExplicitConstructor
    constexpr VUseType(en _e)
        : m_e{_e} {}
    explicit VUseType(int _e)
        : m_e(static_cast<en>(_e)) {}  // Need () or GCC 4.8 false warning
-    bool isInclude() const { return m_e == IMP_INCLUDE || m_e == INT_INCLUDE; }
-    bool isFwdClass() const { return m_e == IMP_FWD_CLASS || m_e == INT_FWD_CLASS; }
    constexpr operator en() const { return m_e; }
+    bool containsAny(VUseType other) { return m_e & other.m_e; }
    const char* ascii() const {
-        static const char* const names[] = {"IMP_INC", "INT_INC", "IMP_FWD", "INT_FWD"};
-        return names[m_e];
+        static const char* const names[] = {"INT_FWD", "INT_INC", "INT_FWD_INC"};
+        return names[m_e - 1];
    }
 };
 constexpr bool operator==(const VUseType& lhs, const VUseType& rhs) { return lhs.m_e == rhs.m_e; }
 constexpr bool operator==(const VUseType& lhs, VUseType::en rhs) { return lhs.m_e == rhs; }
 constexpr bool operator==(VUseType::en lhs, const VUseType& rhs) { return lhs == rhs.m_e; }
+constexpr VUseType::en operator|(VUseType::en lhs, VUseType::en rhs) {
+    return VUseType::en((uint8_t)lhs | (uint8_t)rhs);
+}
+constexpr VUseType::en operator&(VUseType::en lhs, VUseType::en rhs) {
+    return VUseType::en((uint8_t)lhs & (uint8_t)rhs);
+}
 inline std::ostream& operator<<(std::ostream& os, const VUseType& rhs) {
    return os << rhs.ascii();
 }
@@ -1211,6 +1251,44 @@ public:
    ~VBasicTypeKey() = default;
 };

+// ######################################################################
+//  VSelfPointerText - Represents text to be emitted before a given var reference, call, etc. to
+//  serve as a pointer to a 'self' object. For example, it could be empty (no self pointer), or the
+//  string 'this', or 'vlSymsp->...'
+
+class VSelfPointerText final {
+private:
+    // STATIC MEMBERS
+    // Keep these in shared pointers to avoid branching for special cases
+    static const std::shared_ptr<const string> s_emptyp;  // Holds ""
+    static const std::shared_ptr<const string> s_thisp;  // Holds "this"
+
+    // MEMBERS
+    std::shared_ptr<const string> m_strp;
+
+public:
+    // CONSTRUCTORS
+    class Empty {};  // for creator type-overload selection
+    VSelfPointerText(Empty)
+        : m_strp{s_emptyp} {}
+    class This {};  // for creator type-overload selection
+    VSelfPointerText(This)
+        : m_strp{s_thisp} {}
+    VSelfPointerText(This, const string& field)
+        : m_strp{std::make_shared<const string>("this->" + field)} {}
+    class VlSyms {};  // for creator type-overload selection
+    VSelfPointerText(VlSyms, const string& field)
+        : m_strp{std::make_shared<const string>("(&vlSymsp->" + field + ')')} {}
+
+    // METHODS
+    bool isEmpty() const { return m_strp == s_emptyp; }
+    bool isVlSym() const { return m_strp->find("vlSymsp") != string::npos; }
+    bool hasThis() const { return m_strp == s_thisp || VString::startsWith(*m_strp, "this"); }
+    string protect(bool useSelfForThis, bool protect) const;
+    const std::string& asString() const { return *m_strp; }
+    bool operator==(const VSelfPointerText& other) const { return *m_strp == *other.m_strp; }
+};
+
 //######################################################################
 // AstNUser - Generic base class for AST User nodes.
 //          - Also used to allow parameter passing up/down iterate calls
@@ -1293,55 +1371,55 @@ protected:
 class VNUser1InUse final : VNUserInUseBase {
 protected:
    friend class AstNode;
-    static uint32_t     s_userCntGbl;   // Count of which usage of userp() this is
-    static bool         s_userBusy;     // Count is in use
+    static uint32_t s_userCntGbl;  // Count of which usage of userp() this is
+    static bool s_userBusy;  // Count is in use
 public:
-    VNUser1InUse()     { allocate(1, s_userCntGbl/*ref*/, s_userBusy/*ref*/); }
-    ~VNUser1InUse()    { free    (1, s_userCntGbl/*ref*/, s_userBusy/*ref*/); }
+    VNUser1InUse()      { allocate(1, s_userCntGbl/*ref*/, s_userBusy/*ref*/); }
+    ~VNUser1InUse()     { free    (1, s_userCntGbl/*ref*/, s_userBusy/*ref*/); }
    static void clear() { clearcnt(1, s_userCntGbl/*ref*/, s_userBusy/*ref*/); }
    static void check() { checkcnt(1, s_userCntGbl/*ref*/, s_userBusy/*ref*/); }
 };
 class VNUser2InUse final : VNUserInUseBase {
 protected:
    friend class AstNode;
-    static uint32_t     s_userCntGbl;   // Count of which usage of userp() this is
-    static bool         s_userBusy;     // Count is in use
+    static uint32_t s_userCntGbl;  // Count of which usage of userp() this is
+    static bool s_userBusy;  // Count is in use
 public:
-    VNUser2InUse()     { allocate(2, s_userCntGbl/*ref*/, s_userBusy/*ref*/); }
-    ~VNUser2InUse()    { free    (2, s_userCntGbl/*ref*/, s_userBusy/*ref*/); }
+    VNUser2InUse()      { allocate(2, s_userCntGbl/*ref*/, s_userBusy/*ref*/); }
+    ~VNUser2InUse()     { free    (2, s_userCntGbl/*ref*/, s_userBusy/*ref*/); }
    static void clear() { clearcnt(2, s_userCntGbl/*ref*/, s_userBusy/*ref*/); }
    static void check() { checkcnt(2, s_userCntGbl/*ref*/, s_userBusy/*ref*/); }
 };
 class VNUser3InUse final : VNUserInUseBase {
 protected:
    friend class AstNode;
-    static uint32_t     s_userCntGbl;   // Count of which usage of userp() this is
-    static bool         s_userBusy;     // Count is in use
+    static uint32_t s_userCntGbl;  // Count of which usage of userp() this is
+    static bool s_userBusy;  // Count is in use
 public:
-    VNUser3InUse()     { allocate(3, s_userCntGbl/*ref*/, s_userBusy/*ref*/); }
-    ~VNUser3InUse()    { free    (3, s_userCntGbl/*ref*/, s_userBusy/*ref*/); }
+    VNUser3InUse()      { allocate(3, s_userCntGbl/*ref*/, s_userBusy/*ref*/); }
+    ~VNUser3InUse()     { free    (3, s_userCntGbl/*ref*/, s_userBusy/*ref*/); }
    static void clear() { clearcnt(3, s_userCntGbl/*ref*/, s_userBusy/*ref*/); }
    static void check() { checkcnt(3, s_userCntGbl/*ref*/, s_userBusy/*ref*/); }
 };
 class VNUser4InUse final : VNUserInUseBase {
 protected:
    friend class AstNode;
-    static uint32_t     s_userCntGbl;   // Count of which usage of userp() this is
-    static bool         s_userBusy;     // Count is in use
+    static uint32_t s_userCntGbl;  // Count of which usage of userp() this is
+    static bool s_userBusy;  // Count is in use
 public:
-    VNUser4InUse()     { allocate(4, s_userCntGbl/*ref*/, s_userBusy/*ref*/); }
-    ~VNUser4InUse()    { free    (4, s_userCntGbl/*ref*/, s_userBusy/*ref*/); }
+    VNUser4InUse()      { allocate(4, s_userCntGbl/*ref*/, s_userBusy/*ref*/); }
+    ~VNUser4InUse()     { free    (4, s_userCntGbl/*ref*/, s_userBusy/*ref*/); }
    static void clear() { clearcnt(4, s_userCntGbl/*ref*/, s_userBusy/*ref*/); }
    static void check() { checkcnt(4, s_userCntGbl/*ref*/, s_userBusy/*ref*/); }
 };
 class VNUser5InUse final : VNUserInUseBase {
 protected:
    friend class AstNode;
-    static uint32_t     s_userCntGbl;   // Count of which usage of userp() this is
-    static bool         s_userBusy;     // Count is in use
+    static uint32_t s_userCntGbl;  // Count of which usage of userp() this is
+    static bool s_userBusy;  // Count is in use
 public:
-    VNUser5InUse()     { allocate(5, s_userCntGbl/*ref*/, s_userBusy/*ref*/); }
-    ~VNUser5InUse()    { free    (5, s_userCntGbl/*ref*/, s_userBusy/*ref*/); }
+    VNUser5InUse()      { allocate(5, s_userCntGbl/*ref*/, s_userBusy/*ref*/); }
+    ~VNUser5InUse()     { free    (5, s_userCntGbl/*ref*/, s_userBusy/*ref*/); }
    static void clear() { clearcnt(5, s_userCntGbl/*ref*/, s_userBusy/*ref*/); }
    static void check() { checkcnt(5, s_userCntGbl/*ref*/, s_userBusy/*ref*/); }
 };
@@ -1373,13 +1451,38 @@ public:
    virtual ~VNDeleter() { doDeletes(); }
 };

+//######################################################################
+// VNVisitorConst -- Allows new functions to be called on each node
+// type without changing the base classes.  See "Modern C++ Design".
+// This only has the constant fuctions for non-modifying visitors.
+// For more typical usage see VNVisitor
+
+class VNVisitorConst VL_NOT_FINAL : public VNDeleter {
+    friend class AstNode;
+
+public:
+    /// Call visit()s on nodep
+    inline void iterateConst(AstNode* nodep);
+    /// Call visit()s on nodep
+    inline void iterateConstNull(AstNode* nodep);
+    /// Call visit()s on const nodep's children
+    inline void iterateChildrenConst(AstNode* nodep);
+    /// Call visit()s on nodep's children in backp() order
+    inline void iterateChildrenBackwardsConst(AstNode* nodep);
+    /// Call visit()s on const nodep (maybe nullptr) and nodep's nextp() list
+    inline void iterateAndNextConstNull(AstNode* nodep);
+    /// Call visit()s on const nodep (maybe nullptr) and nodep's nextp() list, in reverse order
+    inline void iterateAndNextConstNullBackwards(AstNode* nodep);
+
+    virtual void visit(AstNode* nodep) = 0;
+#include "V3Ast__gen_visitor_decls.h"  // From ./astgen
+};
+
 //######################################################################
 // VNVisitor -- Allows new functions to be called on each node
 // type without changing the base classes.  See "Modern C++ Design".

-class VNVisitor VL_NOT_FINAL : public VNDeleter {
-    friend class AstNode;
-
+class VNVisitor VL_NOT_FINAL : public VNVisitorConst {
 public:
    /// Call visit()s on nodep
    inline void iterate(AstNode* nodep);
@@ -1387,21 +1490,10 @@ public:
    inline void iterateNull(AstNode* nodep);
    /// Call visit()s on nodep's children
    inline void iterateChildren(AstNode* nodep);
-    /// Call visit()s on nodep's children in backp() order
-    inline void iterateChildrenBackwards(AstNode* nodep);
-    /// Call visit()s on const nodep's children
-    inline void iterateChildrenConst(AstNode* nodep);
    /// Call visit()s on nodep (maybe nullptr) and nodep's nextp() list
    inline void iterateAndNextNull(AstNode* nodep);
-    /// Call visit()s on const nodep (maybe nullptr) and nodep's nextp() list
-    inline void iterateAndNextConstNull(AstNode* nodep);
-    /// Call visit()s on const nodep (maybe nullptr) and nodep's nextp() list, in reverse order
-    inline void iterateAndNextConstNullBackwards(AstNode* nodep);
    /// Return edited nodep; see comments in V3Ast.cpp
    inline AstNode* iterateSubtreeReturnEdits(AstNode* nodep);
-
-    virtual void visit(AstNode* nodep) = 0;
-#include "V3Ast__gen_visitor_decls.h"  // From ./astgen
 };

 //######################################################################
@@ -1426,6 +1518,13 @@ protected:

 public:
    VNRelinker() = default;
+    ~VNRelinker() {
+        // Relink is needed so m_iterpp's get restored, e.g. can't have:
+        // ->unlinkFrBack(relinker);
+        // if (only_sometimes) relinker.relink(newp);
+        UDEBUGONLY(
+            UASSERT_STATIC(!m_backp, "Active linker must be relink()ed before destruction"););
+    }
    inline void relink(AstNode* newp);
    AstNode* oldp() const { return m_oldp; }
    void dump(std::ostream& str = std::cout) const;
@@ -1545,7 +1644,7 @@ class AstNode VL_NOT_FINAL {
 private:
    AstNode* cloneTreeIter();
    AstNode* cloneTreeIterList();
-    void checkTreeIter(const AstNode* prevBackp) const VL_MT_SAFE;
+    void checkTreeIter(const AstNode* prevBackp) const VL_MT_STABLE;
    bool gateTreeIter() const;
    static bool sameTreeIter(const AstNode* node1p, const AstNode* node2p, bool ignNext,
                             bool gateOnly);
@@ -1601,14 +1700,14 @@ public:
    // ACCESSORS
    VNType type() const VL_MT_SAFE { return m_type; }
    const char* typeName() const VL_MT_SAFE { return type().ascii(); }  // See also prettyTypeName
-    AstNode* nextp() const VL_MT_SAFE { return m_nextp; }
-    AstNode* backp() const VL_MT_SAFE { return m_backp; }
-    AstNode* abovep() const;  // Parent node above, only when no nextp() as otherwise slow
-    AstNode* op1p() const VL_MT_SAFE { return m_op1p; }
-    AstNode* op2p() const VL_MT_SAFE { return m_op2p; }
-    AstNode* op3p() const VL_MT_SAFE { return m_op3p; }
-    AstNode* op4p() const VL_MT_SAFE { return m_op4p; }
-    AstNodeDType* dtypep() const VL_MT_SAFE { return m_dtypep; }
+    AstNode* nextp() const VL_MT_STABLE { return m_nextp; }
+    AstNode* backp() const VL_MT_STABLE { return m_backp; }
+    AstNode* abovep() const;  // Get parent node above, only for list head and tail
+    AstNode* op1p() const VL_MT_STABLE { return m_op1p; }
+    AstNode* op2p() const VL_MT_STABLE { return m_op2p; }
+    AstNode* op3p() const VL_MT_STABLE { return m_op3p; }
+    AstNode* op4p() const VL_MT_STABLE { return m_op4p; }
+    AstNodeDType* dtypep() const VL_MT_STABLE { return m_dtypep; }
    AstNode* clonep() const { return ((m_cloneCnt == s_cloneCntGbl) ? m_clonep : nullptr); }
    AstNode* firstAbovep() const {  // Returns nullptr when second or later in list
        return ((backp() && backp()->nextp() != this) ? backp() : nullptr);
@@ -1655,7 +1754,7 @@ public:
    static constexpr int INSTR_COUNT_PLI = 20;  // PLI routines

    // ACCESSORS
-    virtual string name() const VL_MT_SAFE { return ""; }
+    virtual string name() const { return ""; }
    virtual string origName() const { return ""; }
    virtual void name(const string& name) {
        this->v3fatalSrc("name() called on object without name() method");
@@ -1663,22 +1762,23 @@ public:
    virtual void tag(const string& text) {}
    virtual string tag() const { return ""; }
    virtual string verilogKwd() const { return ""; }
-    string nameProtect() const VL_MT_SAFE;  // Name with --protect-id applied
+    string nameProtect() const;  // Name with --protect-id applied
    string origNameProtect() const;  // origName with --protect-id applied
    string shortName() const;  // Name with __PVT__ removed for concatenating scopes
    static string dedotName(const string& namein);  // Name with dots removed
-    static string prettyName(const string& namein);  // Name for printing out to the user
+    static string prettyName(const string& namein) VL_PURE;  // Name for printing out to the user
    static string vpiName(const string& namein);  // Name for vpi access
    static string prettyNameQ(const string& namein) {  // Quoted pretty name (for errors)
        return std::string{"'"} + prettyName(namein) + "'";
    }
-    static string
-    encodeName(const string& namein);  // Encode user name into internal C representation
+    // Encode user name into internal C representation
+    static string encodeName(const string& namein);
    static string encodeNumber(int64_t num);  // Encode number into internal C representation
    static string vcdName(const string& namein);  // Name for printing out to vcd files
-    string prettyName() const VL_MT_SAFE { return prettyName(name()); }
+    string prettyName() const { return prettyName(name()); }
    string prettyNameQ() const { return prettyNameQ(name()); }
-    string prettyTypeName() const;  // "VARREF" for error messages (NOT dtype's pretty name)
+    // "VARREF" for error messages (NOT dtype's pretty name)
+    string prettyTypeName() const;
    virtual string prettyOperatorName() const { return "operator " + prettyTypeName(); }
    FileLine* fileline() const VL_MT_SAFE { return m_fileline; }
    void fileline(FileLine* fl) { m_fileline = fl; }
@@ -1697,87 +1797,87 @@ public:
    void protect(bool flag) { m_flags.protect = flag; }

    // TODO stomp these width functions out, and call via dtypep() instead
-    inline int width() const VL_MT_SAFE;
+    inline int width() const VL_MT_STABLE;
    inline int widthMin() const;
    int widthMinV() const {
        return v3Global.widthMinUsage() == VWidthMinUsage::VERILOG_WIDTH ? widthMin() : width();
    }
    int widthWords() const { return VL_WORDS_I(width()); }
-    bool isQuad() const VL_MT_SAFE { return (width() > VL_IDATASIZE && width() <= VL_QUADSIZE); }
-    bool isWide() const VL_MT_SAFE { return (width() > VL_QUADSIZE); }
-    inline bool isDouble() const;
-    inline bool isSigned() const;
-    inline bool isString() const;
+    bool isQuad() const VL_MT_STABLE { return (width() > VL_IDATASIZE && width() <= VL_QUADSIZE); }
+    bool isWide() const VL_MT_STABLE { return (width() > VL_QUADSIZE); }
+    inline bool isDouble() const VL_MT_STABLE;
+    inline bool isSigned() const VL_MT_STABLE;
+    inline bool isString() const VL_MT_STABLE;

    // clang-format off
-    VNUser      user1u() const VL_MT_SAFE {
+    VNUser user1u() const VL_MT_STABLE {
        // Slows things down measurably, so disabled by default
-        //UASSERT_STATIC(VNUser1InUse::s_userBusy, "userp set w/o busy");
-        return ((m_user1Cnt==VNUser1InUse::s_userCntGbl) ? m_user1u : VNUser{0});
+        //UASSERT_STATIC(VNUser1InUse::s_userBusy, "user1p used without AstUserInUse");
+        return ((m_user1Cnt == VNUser1InUse::s_userCntGbl) ? m_user1u : VNUser{0});
    }
-    AstNode*    user1p() const VL_MT_SAFE { return user1u().toNodep(); }
-    void        user1u(const VNUser& user) { m_user1u=user; m_user1Cnt=VNUser1InUse::s_userCntGbl; }
-    void        user1p(void* userp) { user1u(VNUser{userp}); }
-    int         user1() const { return user1u().toInt(); }
-    void        user1(int val) { user1u(VNUser{val}); }
-    int         user1Inc(int val=1) { int v=user1(); user1(v+val); return v; }
-    int         user1SetOnce() { int v=user1(); if (!v) user1(1); return v; }  // Better for cache than user1Inc()
+    AstNode* user1p() const VL_MT_STABLE { return user1u().toNodep(); }
+    void user1u(const VNUser& user) { m_user1u = user; m_user1Cnt = VNUser1InUse::s_userCntGbl; }
+    void user1p(void* userp) { user1u(VNUser{userp}); }
+    void user1(int val) { user1u(VNUser{val}); }
+    int user1() const { return user1u().toInt(); }
+    int user1Inc(int val = 1) { int v = user1(); user1(v + val); return v; }
+    int user1SetOnce() { int v = user1(); if (!v) user1(1); return v; }  // Better for cache than user1Inc()
    static void user1ClearTree() { VNUser1InUse::clear(); }  // Clear userp()'s across the entire tree

-    VNUser      user2u() const VL_MT_SAFE {
+    VNUser user2u() const VL_MT_STABLE {
        // Slows things down measurably, so disabled by default
-        //UASSERT_STATIC(VNUser2InUse::s_userBusy, "userp set w/o busy");
-        return ((m_user2Cnt==VNUser2InUse::s_userCntGbl) ? m_user2u : VNUser{0});
+        //UASSERT_STATIC(VNUser2InUse::s_userBusy, "user2p used without AstUserInUse");
+        return ((m_user2Cnt == VNUser2InUse::s_userCntGbl) ? m_user2u : VNUser{0});
    }
-    AstNode*    user2p() const VL_MT_SAFE { return user2u().toNodep(); }
-    void        user2u(const VNUser& user) { m_user2u=user; m_user2Cnt=VNUser2InUse::s_userCntGbl; }
-    void        user2p(void* userp) { user2u(VNUser{userp}); }
-    int         user2() const { return user2u().toInt(); }
-    void        user2(int val) { user2u(VNUser{val}); }
-    int         user2Inc(int val=1) { int v=user2(); user2(v+val); return v; }
-    int         user2SetOnce() { int v=user2(); if (!v) user2(1); return v; }  // Better for cache than user2Inc()
+    AstNode* user2p() const VL_MT_STABLE { return user2u().toNodep(); }
+    void user2u(const VNUser& user) { m_user2u = user; m_user2Cnt = VNUser2InUse::s_userCntGbl; }
+    void user2p(void* userp) { user2u(VNUser{userp}); }
+    void user2(int val) { user2u(VNUser{val}); }
+    int user2() const { return user2u().toInt(); }
+    int user2Inc(int val = 1) { int v = user2(); user2(v + val); return v; }
+    int user2SetOnce() { int v = user2(); if (!v) user2(1); return v; }  // Better for cache than user2Inc()
    static void user2ClearTree() { VNUser2InUse::clear(); }  // Clear userp()'s across the entire tree

-    VNUser      user3u() const VL_MT_SAFE {
+    VNUser user3u() const VL_MT_STABLE {
        // Slows things down measurably, so disabled by default
-        //UASSERT_STATIC(VNUser3InUse::s_userBusy, "userp set w/o busy");
-        return ((m_user3Cnt==VNUser3InUse::s_userCntGbl) ? m_user3u : VNUser{0});
+        //UASSERT_STATIC(VNUser3InUse::s_userBusy, "user3p used without AstUserInUse");
+        return ((m_user3Cnt == VNUser3InUse::s_userCntGbl) ? m_user3u : VNUser{0});
    }
-    AstNode*    user3p() const VL_MT_SAFE { return user3u().toNodep(); }
-    void        user3u(const VNUser& user) { m_user3u=user; m_user3Cnt=VNUser3InUse::s_userCntGbl; }
-    void        user3p(void* userp) { user3u(VNUser{userp}); }
-    int         user3() const { return user3u().toInt(); }
-    void        user3(int val) { user3u(VNUser{val}); }
-    int         user3Inc(int val=1) { int v=user3(); user3(v+val); return v; }
-    int         user3SetOnce() { int v=user3(); if (!v) user3(1); return v; }  // Better for cache than user3Inc()
+    AstNode* user3p() const VL_MT_STABLE { return user3u().toNodep(); }
+    void user3u(const VNUser& user) { m_user3u = user; m_user3Cnt = VNUser3InUse::s_userCntGbl; }
+    void user3p(void* userp) { user3u(VNUser{userp}); }
+    void user3(int val) { user3u(VNUser{val}); }
+    int user3() const { return user3u().toInt(); }
+    int user3Inc(int val = 1) { int v = user3(); user3(v + val); return v; }
+    int user3SetOnce() { int v = user3(); if (!v) user3(1); return v; }  // Better for cache than user3Inc()
    static void user3ClearTree() { VNUser3InUse::clear(); }  // Clear userp()'s across the entire tree

-    VNUser      user4u() const VL_MT_SAFE {
+    VNUser user4u() const VL_MT_STABLE {
        // Slows things down measurably, so disabled by default
-        //UASSERT_STATIC(VNUser4InUse::s_userBusy, "userp set w/o busy");
-        return ((m_user4Cnt==VNUser4InUse::s_userCntGbl) ? m_user4u : VNUser{0});
+        //UASSERT_STATIC(VNUser4InUse::s_userBusy, "user4p used without AstUserInUse");
+        return ((m_user4Cnt == VNUser4InUse::s_userCntGbl) ? m_user4u : VNUser{0});
    }
-    AstNode*    user4p() const VL_MT_SAFE { return user4u().toNodep(); }
-    void        user4u(const VNUser& user) { m_user4u=user; m_user4Cnt=VNUser4InUse::s_userCntGbl; }
-    void        user4p(void* userp) { user4u(VNUser{userp}); }
-    int         user4() const { return user4u().toInt(); }
-    void        user4(int val) { user4u(VNUser{val}); }
-    int         user4Inc(int val=1) { int v=user4(); user4(v+val); return v; }
-    int         user4SetOnce() { int v=user4(); if (!v) user4(1); return v; }  // Better for cache than user4Inc()
+    AstNode* user4p() const VL_MT_STABLE { return user4u().toNodep(); }
+    void user4u(const VNUser& user) { m_user4u = user; m_user4Cnt = VNUser4InUse::s_userCntGbl; }
+    void user4p(void* userp) { user4u(VNUser{userp}); }
+    void user4(int val) { user4u(VNUser{val}); }
+    int user4() const { return user4u().toInt(); }
+    int user4Inc(int val = 1) { int v = user4(); user4(v + val); return v; }
+    int user4SetOnce() { int v = user4(); if (!v) user4(1); return v; }  // Better for cache than user4Inc()
    static void user4ClearTree() { VNUser4InUse::clear(); }  // Clear userp()'s across the entire tree

-    VNUser      user5u() const VL_MT_SAFE {
+    VNUser user5u() const VL_MT_STABLE {
        // Slows things down measurably, so disabled by default
-        //UASSERT_STATIC(VNUser5InUse::s_userBusy, "userp set w/o busy");
-        return ((m_user5Cnt==VNUser5InUse::s_userCntGbl) ? m_user5u : VNUser{0});
+        //UASSERT_STATIC(VNUser5InUse::s_userBusy, "user5p used without AstUserInUse");
+        return ((m_user5Cnt == VNUser5InUse::s_userCntGbl) ? m_user5u : VNUser{0});
    }
-    AstNode*    user5p() const VL_MT_SAFE { return user5u().toNodep(); }
-    void        user5u(const VNUser& user) { m_user5u=user; m_user5Cnt=VNUser5InUse::s_userCntGbl; }
-    void        user5p(void* userp) { user5u(VNUser{userp}); }
-    int         user5() const { return user5u().toInt(); }
-    void        user5(int val) { user5u(VNUser{val}); }
-    int         user5Inc(int val=1) { int v=user5(); user5(v+val); return v; }
-    int         user5SetOnce() { int v=user5(); if (!v) user5(1); return v; }  // Better for cache than user5Inc()
+    AstNode* user5p() const VL_MT_STABLE { return user5u().toNodep(); }
+    void user5u(const VNUser& user) { m_user5u = user; m_user5Cnt = VNUser5InUse::s_userCntGbl; }
+    void user5p(void* userp) { user5u(VNUser{userp}); }
+    void user5(int val) { user5u(VNUser{val}); }
+    int user5() const { return user5u().toInt(); }
+    int user5Inc(int val = 1) { int v = user5(); user5(v + val); return v; }
+    int user5SetOnce() { int v = user5(); if (!v) user5(1); return v; }  // Better for cache than user5Inc()
    static void user5ClearTree() { VNUser5InUse::clear(); }  // Clear userp()'s across the entire tree
    // clang-format on

@@ -1795,6 +1895,7 @@ public:

    // ACCESSORS for specific types
    // Alas these can't be virtual or they break when passed a nullptr
+    inline bool isClassHandleValue() const;
    inline bool isZero() const;
    inline bool isOne() const;
    inline bool isNeqZero() const;
@@ -1834,6 +1935,7 @@ public:
    void dtypeSetUInt64() { dtypep(findUInt64DType()); }  // Twostate
    void dtypeSetEmptyQueue() { dtypep(findEmptyQueueDType()); }
    void dtypeSetVoid() { dtypep(findVoidDType()); }
+    void dtypeSetStream() { dtypep(findStreamDType()); }

    // Data type locators
    AstNodeDType* findBitDType() const { return findBasicDType(VBasicDTypeKwd::LOGIC); }
@@ -1845,6 +1947,7 @@ public:
    AstNodeDType* findCHandleDType() const { return findBasicDType(VBasicDTypeKwd::CHANDLE); }
    AstNodeDType* findEmptyQueueDType() const;
    AstNodeDType* findVoidDType() const;
+    AstNodeDType* findStreamDType() const;
    AstNodeDType* findQueueIndexDType() const;
    AstNodeDType* findBitDType(int width, int widthMin, VSigning numeric) const;
    AstNodeDType* findLogicDType(int width, int widthMin, VSigning numeric) const;
@@ -1855,9 +1958,9 @@ public:
    static AstBasicDType* findInsertSameDType(AstBasicDType* nodep);

    // METHODS - dump and error
-    void v3errorEnd(std::ostringstream& str) const VL_REQUIRES(V3Error::s().m_mutex);
+    void v3errorEnd(std::ostringstream& str) const VL_RELEASE(V3Error::s().m_mutex);
    void v3errorEndFatal(std::ostringstream& str) const VL_ATTR_NORETURN
-        VL_REQUIRES(V3Error::s().m_mutex);
+        VL_RELEASE(V3Error::s().m_mutex);
    string warnContextPrimary() const VL_REQUIRES(V3Error::s().m_mutex) {
        return fileline()->warnContextPrimary();
    }
@@ -1893,21 +1996,15 @@ public:
    // Iterate and insert - assumes tree format
    virtual void addNextStmt(AstNode* newp,
                             AstNode* belowp);  // When calling, "this" is second argument
-    virtual void addBeforeStmt(AstNode* newp,
-                               AstNode* belowp);  // When calling, "this" is second argument

    // METHODS - Iterate on a tree
-    // Clone or return nullptr if nullptr
-    static AstNode* cloneTreeNull(AstNode* nodep, bool cloneNextLink) {
-        return nodep ? nodep->cloneTree(cloneNextLink) : nullptr;
-    }
    AstNode* cloneTree(bool cloneNextLink);  // Not const, as sets clonep() on original nodep
    bool gateTree() { return gateTreeIter(); }  // Is tree isGateOptimizable?
    inline bool sameTree(const AstNode* node2p) const;  // Does tree of this == node2p?
    // Does tree of this == node2p?, not allowing non-isGateOptimizable
    inline bool sameGateTree(const AstNode* node2p) const;
    void deleteTree();  // Always deletes the next link
-    void checkTree() const VL_MT_SAFE {
+    void checkTree() const VL_MT_STABLE {
        if (v3Global.opt.debugCheck()) checkTreeIter(backp());
    }
    void checkIter() const;
@@ -1964,26 +2061,27 @@ public:
    virtual const char* broken() const { return nullptr; }

    // INVOKERS
-    virtual void accept(VNVisitor& v) = 0;
+    virtual void accept(VNVisitorConst& v) = 0;

 protected:
    // All VNVisitor related functions are called as methods off the visitor
    friend class VNVisitor;
+    friend class VNVisitorConst;
    // Use instead VNVisitor::iterateChildren
    void iterateChildren(VNVisitor& v);
-    // Use instead VNVisitor::iterateChildrenBackwards
-    void iterateChildrenBackwards(VNVisitor& v);
+    // Use instead VNVisitor::iterateChildrenBackwardsConst
+    void iterateChildrenBackwardsConst(VNVisitorConst& v);
    // Use instead VNVisitor::iterateChildrenConst
-    void iterateChildrenConst(VNVisitor& v);
+    void iterateChildrenConst(VNVisitorConst& v);
    // Use instead VNVisitor::iterateAndNextNull
    void iterateAndNext(VNVisitor& v);
    // Use instead VNVisitor::iterateAndNextConstNull
-    void iterateAndNextConst(VNVisitor& v);
+    void iterateAndNextConst(VNVisitorConst& v);
    // Use instead VNVisitor::iterateSubtreeReturnEdits
    AstNode* iterateSubtreeReturnEdits(VNVisitor& v);

 private:
-    void iterateListBackwards(VNVisitor& v);
+    void iterateListBackwardsConst(VNVisitorConst& v);

    // For internal use only.
    // Note: specializations for particular node types are provided by 'astgen'
@@ -1992,7 +2090,7 @@ private:

    // For internal use only.
    template <typename TargetType, typename DeclType>
-    constexpr static bool uselessCast() {
+    constexpr static bool uselessCast() VL_PURE {
        using NonRef = typename std::remove_reference<DeclType>::type;
        using NonPtr = typename std::remove_pointer<NonRef>::type;
        using NonCV = typename std::remove_cv<NonPtr>::type;
@@ -2001,7 +2099,7 @@ private:

    // For internal use only.
    template <typename TargetType, typename DeclType>
-    constexpr static bool impossibleCast() {
+    constexpr static bool impossibleCast() VL_PURE {
        using NonRef = typename std::remove_reference<DeclType>::type;
        using NonPtr = typename std::remove_pointer<NonRef>::type;
        using NonCV = typename std::remove_cv<NonPtr>::type;
@@ -2033,24 +2131,34 @@ public:
        return nodep && privateTypeTest<T>(nodep) ? reinterpret_cast<const T*>(nodep) : nullptr;
    }

-    // For use via the VN_AS macro only
+    // For use via privateAs or the VN_DBG_AS macro only
    template <typename T, typename E>
-    static T* privateAs(AstNode* nodep) VL_MT_SAFE {
+    static T* unsafePrivateAs(AstNode* nodep) VL_PURE {
        static_assert(!uselessCast<T, E>(), "Unnecessary VN_AS, node known to have target type.");
        static_assert(!impossibleCast<T, E>(), "Unnecessary VN_AS, node cannot be this type.");
-        UASSERT_OBJ(!nodep || privateTypeTest<T>(nodep), nodep,
-                    "AstNode is not of expected type, but instead has type '" << nodep->typeName()
-                                                                              << "'");
        return reinterpret_cast<T*>(nodep);
    }
    template <typename T, typename E>
-    static const T* privateAs(const AstNode* nodep) VL_MT_SAFE {
+    static const T* unsafePrivateAs(const AstNode* nodep) VL_PURE {
        static_assert(!uselessCast<T, E>(), "Unnecessary VN_AS, node known to have target type.");
        static_assert(!impossibleCast<T, E>(), "Unnecessary VN_AS, node cannot be this type.");
+        return reinterpret_cast<const T*>(nodep);
+    }
+
+    // For use via the VN_AS macro only
+    template <typename T, typename E>
+    static T* privateAs(AstNode* nodep) VL_PURE {
        UASSERT_OBJ(!nodep || privateTypeTest<T>(nodep), nodep,
                    "AstNode is not of expected type, but instead has type '" << nodep->typeName()
                                                                              << "'");
-        return reinterpret_cast<const T*>(nodep);
+        return unsafePrivateAs<T, E>(nodep);
+    }
+    template <typename T, typename E>
+    static const T* privateAs(const AstNode* nodep) VL_PURE {
+        UASSERT_OBJ(!nodep || privateTypeTest<T>(nodep), nodep,
+                    "AstNode is not of expected type, but instead has type '" << nodep->typeName()
+                                                                              << "'");
+        return unsafePrivateAs<T, E>(nodep);
    }

    // Predicate that returns true if the given 'nodep' might have a descendant of type 'T_Node'.
@@ -2483,24 +2591,29 @@ struct std::equal_to<VNRef<T_Node>> final {
 //######################################################################
 // Inline VNVisitor METHODS

+void VNVisitorConst::iterateConst(AstNode* nodep) { nodep->accept(*this); }
+void VNVisitorConst::iterateConstNull(AstNode* nodep) {
+    if (VL_LIKELY(nodep)) nodep->accept(*this);
+}
+void VNVisitorConst::iterateChildrenConst(AstNode* nodep) { nodep->iterateChildrenConst(*this); }
+void VNVisitorConst::iterateChildrenBackwardsConst(AstNode* nodep) {
+    nodep->iterateChildrenBackwardsConst(*this);
+}
+void VNVisitorConst::iterateAndNextConstNullBackwards(AstNode* nodep) {
+    if (VL_LIKELY(nodep)) nodep->iterateListBackwardsConst(*this);
+}
+void VNVisitorConst::iterateAndNextConstNull(AstNode* nodep) {
+    if (VL_LIKELY(nodep)) nodep->iterateAndNextConst(*this);
+}
+
 void VNVisitor::iterate(AstNode* nodep) { nodep->accept(*this); }
 void VNVisitor::iterateNull(AstNode* nodep) {
    if (VL_LIKELY(nodep)) nodep->accept(*this);
 }
 void VNVisitor::iterateChildren(AstNode* nodep) { nodep->iterateChildren(*this); }
-void VNVisitor::iterateChildrenBackwards(AstNode* nodep) {
-    nodep->iterateChildrenBackwards(*this);
-}
-void VNVisitor::iterateChildrenConst(AstNode* nodep) { nodep->iterateChildrenConst(*this); }
 void VNVisitor::iterateAndNextNull(AstNode* nodep) {
    if (VL_LIKELY(nodep)) nodep->iterateAndNext(*this);
 }
-void VNVisitor::iterateAndNextConstNullBackwards(AstNode* nodep) {
-    if (VL_LIKELY(nodep)) nodep->iterateListBackwards(*this);
-}
-void VNVisitor::iterateAndNextConstNull(AstNode* nodep) {
-    if (VL_LIKELY(nodep)) nodep->iterateAndNextConst(*this);
-}
 AstNode* VNVisitor::iterateSubtreeReturnEdits(AstNode* nodep) {
    return nodep->iterateSubtreeReturnEdits(*this);
 }
@@ -25,7 +25,7 @@
 //######################################################################
 // Inline METHODS

-int AstNode::width() const { return dtypep() ? dtypep()->width() : 0; }
+int AstNode::width() const VL_MT_STABLE { 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;
@@ -33,14 +33,18 @@ bool AstNode::width1() const {  // V3Const uses to know it can optimize
 int AstNode::widthInstrs() const {
    return (!dtypep() ? 1 : (dtypep()->isWide() ? dtypep()->widthWords() : 1));
 }
-bool AstNode::isDouble() const VL_MT_SAFE {
+bool AstNode::isDouble() const VL_MT_STABLE {
    return dtypep() && VN_IS(dtypep(), BasicDType) && VN_AS(dtypep(), BasicDType)->isDouble();
 }
-bool AstNode::isString() const VL_MT_SAFE {
+bool AstNode::isString() const VL_MT_STABLE {
    return dtypep() && dtypep()->basicp() && dtypep()->basicp()->isString();
 }
-bool AstNode::isSigned() const { return dtypep() && dtypep()->isSigned(); }
+bool AstNode::isSigned() const VL_MT_STABLE { return dtypep() && dtypep()->isSigned(); }

+bool AstNode::isClassHandleValue() const {
+    return (VN_IS(this, Const) && VN_AS(this, Const)->num().isNull())
+           || VN_IS(dtypep(), ClassRefDType);
+}
 bool AstNode::isZero() const {
    return (VN_IS(this, Const) && VN_AS(this, Const)->num().isEqZero());
 }
@@ -61,12 +65,12 @@ bool AstNode::sameGateTree(const AstNode* node2p) const {
    return sameTreeIter(this, node2p, true, true);
 }

-int AstNodeArrayDType::left() const VL_MT_SAFE { return rangep()->leftConst(); }
-int AstNodeArrayDType::right() const VL_MT_SAFE { return rangep()->rightConst(); }
-int AstNodeArrayDType::hi() const VL_MT_SAFE { return rangep()->hiConst(); }
-int AstNodeArrayDType::lo() const VL_MT_SAFE { return rangep()->loConst(); }
-int AstNodeArrayDType::elementsConst() const VL_MT_SAFE { return rangep()->elementsConst(); }
-VNumRange AstNodeArrayDType::declRange() const VL_MT_SAFE { return VNumRange{left(), right()}; }
+int AstNodeArrayDType::left() const VL_MT_STABLE { return rangep()->leftConst(); }
+int AstNodeArrayDType::right() const VL_MT_STABLE { return rangep()->rightConst(); }
+int AstNodeArrayDType::hi() const VL_MT_STABLE { return rangep()->hiConst(); }
+int AstNodeArrayDType::lo() const VL_MT_STABLE { return rangep()->loConst(); }
+int AstNodeArrayDType::elementsConst() const VL_MT_STABLE { return rangep()->elementsConst(); }
+VNumRange AstNodeArrayDType::declRange() const VL_MT_STABLE { return VNumRange{left(), right()}; }

 AstRange::AstRange(FileLine* fl, int left, int right)
    : ASTGEN_SUPER_Range(fl) {
@@ -78,16 +82,16 @@ AstRange::AstRange(FileLine* fl, const VNumRange& range)
    leftp(new AstConst{fl, static_cast<uint32_t>(range.left())});
    rightp(new AstConst{fl, static_cast<uint32_t>(range.right())});
 }
-int AstRange::leftConst() const {
+int AstRange::leftConst() const VL_MT_STABLE {
    AstConst* const constp = VN_CAST(leftp(), Const);
    return (constp ? constp->toSInt() : 0);
 }
-int AstRange::rightConst() const {
+int AstRange::rightConst() const VL_MT_STABLE {
    AstConst* const constp = VN_CAST(rightp(), Const);
    return (constp ? constp->toSInt() : 0);
 }

-int AstQueueDType::boundConst() const VL_MT_SAFE {
+int AstQueueDType::boundConst() const VL_MT_STABLE {
    AstConst* const constp = VN_CAST(boundp(), Const);
    return (constp ? constp->toSInt() : 0);
 }
@@ -123,8 +127,8 @@ int AstBasicDType::lo() const { return (rangep() ? rangep()->loConst() : m.m_nra
 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 AstBasicDType::ascending() const {
+    return (rangep() ? rangep()->ascending() : m.m_nrange.ascending());
 }

 bool AstActive::hasClocked() const { return m_sensesp->hasClocked(); }
@@ -150,12 +154,15 @@ AstCExpr::AstCExpr(FileLine* fl, const string& textStmt, int setwidth, bool clea
 }

 AstVarRef::AstVarRef(FileLine* fl, AstVar* varp, const VAccess& access)
-    : ASTGEN_SUPER_VarRef(fl, varp->name(), varp, access) {}
+    : ASTGEN_SUPER_VarRef(fl, 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) {
+    : ASTGEN_SUPER_VarRef(fl, varscp->varp(), access) {
    varScopep(varscp);
 }
+
+string AstVarRef::name() const { return varp() ? varp()->name() : "<null>"; }
+
 bool AstVarRef::same(const AstVarRef* samep) const {
    if (varScopep()) {
        return (varScopep() == samep->varScopep() && access() == samep->access());
@@ -169,13 +176,14 @@ bool AstVarRef::sameNoLvalue(AstVarRef* samep) const {
        return (varScopep() == samep->varScopep());
    } else {
        return (selfPointer() == samep->selfPointer()
-                && (!selfPointer().empty() || !samep->selfPointer().empty())
+                && (!selfPointer().isEmpty() || !samep->selfPointer().isEmpty())
                && 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)
+    : ASTGEN_SUPER_VarXRef(fl, varp, access)
+    , m_name{varp->name()}
    , m_dotted{dotted} {
    dtypeFrom(varp);
 }
@@ -63,9 +63,9 @@ public:
    // Integral or packed, allowed inside an unpacked union/struct
    virtual bool isIntegralOrPacked() const { return !isCompound(); }
    // (Slow) recurse down to find basic data type
-    virtual AstBasicDType* basicp() const = 0;
+    virtual AstBasicDType* basicp() const VL_MT_STABLE = 0;
    // recurses over typedefs/const/enum to next non-typeref type
-    virtual AstNodeDType* skipRefp() const = 0;
+    virtual AstNodeDType* skipRefp() const VL_MT_STABLE = 0;
    // recurses over typedefs to next non-typeref-or-const type
    virtual AstNodeDType* skipRefToConstp() const = 0;
    // recurses over typedefs/const to next non-typeref-or-enum/struct type
@@ -86,7 +86,7 @@ public:
    // Assignable equivalence.  Call skipRefp() on this and samep before calling
    virtual bool similarDType(const AstNodeDType* samep) const = 0;
    // Iff has a non-null subDTypep(), as generic node function
-    virtual AstNodeDType* subDTypep() const { return nullptr; }
+    virtual AstNodeDType* subDTypep() const VL_MT_SAFE { return nullptr; }
    virtual bool isFourstate() const;
    // Ideally an IEEE $typename
    virtual string prettyDTypeName() const { return prettyTypeName(); }
@@ -126,12 +126,13 @@ public:
    const char* charIQWN() const {
        return (isString() ? "N" : isWide() ? "W" : isQuad() ? "Q" : "I");
    }
-    string cType(const string& name, bool forFunc, bool isRef) const VL_MT_SAFE;
-    bool isLiteralType() const VL_MT_SAFE;  // Represents a C++ LiteralType? (can be constexpr)
+    string cType(const string& name, bool forFunc, bool isRef) const;
+    // Represents a C++ LiteralType? (can be constexpr)
+    bool isLiteralType() const VL_MT_STABLE;

 private:
    class CTypeRecursed;
-    CTypeRecursed cTypeRecurse(bool compound) const VL_MT_SAFE;
+    CTypeRecursed cTypeRecurse(bool compound) const;
 };
 class AstNodeArrayDType VL_NOT_FINAL : public AstNodeDType {
    // Array data type, ie "some_dtype var_name [2:0]"
@@ -170,40 +171,37 @@ public:
                && subDTypep()->skipRefp()->similarDType(asamep->subDTypep()->skipRefp()));
    }
    AstNodeDType* getChildDTypep() const override { return childDTypep(); }
-    AstNodeDType* subDTypep() const override VL_MT_SAFE {
+    AstNodeDType* subDTypep() const override VL_MT_STABLE {
        return m_refDTypep ? m_refDTypep : childDTypep();
    }
    void refDTypep(AstNodeDType* nodep) { m_refDTypep = nodep; }
    AstNodeDType* virtRefDTypep() const override { return m_refDTypep; }
    void virtRefDTypep(AstNodeDType* nodep) override { refDTypep(nodep); }
    // METHODS
-    AstBasicDType* basicp() const override VL_MT_SAFE {
+    AstBasicDType* basicp() const override VL_MT_STABLE {
        return subDTypep()->basicp();
    }  // (Slow) recurse down to find basic data type
-    AstNodeDType* skipRefp() const override VL_MT_SAFE { return (AstNodeDType*)this; }
+    AstNodeDType* skipRefp() const override VL_MT_STABLE { return (AstNodeDType*)this; }
    AstNodeDType* skipRefToConstp() const override { return (AstNodeDType*)this; }
    AstNodeDType* skipRefToEnump() const override { return (AstNodeDType*)this; }
    int widthAlignBytes() const override { return subDTypep()->widthAlignBytes(); }
    int widthTotalBytes() const override {
        return elementsConst() * subDTypep()->widthTotalBytes();
    }
-    inline int left() const;
-    inline int right() const;
-    inline int hi() const;
-    inline int lo() const;
-    inline int elementsConst() const;
-    inline VNumRange declRange() const;
+    inline int left() const VL_MT_STABLE;
+    inline int right() const VL_MT_STABLE;
+    inline int hi() const VL_MT_STABLE;
+    inline int lo() const VL_MT_STABLE;
+    inline int elementsConst() const VL_MT_STABLE;
+    inline VNumRange declRange() const VL_MT_STABLE;
 };
 class AstNodeUOrStructDType VL_NOT_FINAL : public AstNodeDType {
    // A struct or union; common handling
    // @astgen op1 := membersp : List[AstMemberDType]
 private:
-    // TYPES
-    using MemberNameMap = std::map<const std::string, AstMemberDType*>;
    // MEMBERS
    string m_name;  // Name from upper typedef, if any
-    AstNodeModule* m_classOrPackagep = nullptr;  // Package hierarchy
-    MemberNameMap m_members;
+    AstNodeModule* m_classOrPackagep = nullptr;  // Package it will be emitted with
    const int m_uniqueNum;
    bool m_packed;
    bool m_isFourstate = false;  // V3Width computes
@@ -231,7 +229,7 @@ public:
                    : VN_AS(findBitRangeDType(VNumRange{width() - 1, 0}, width(), numeric()),
                            BasicDType));
    }
-    AstNodeDType* skipRefp() const override VL_MT_SAFE { return (AstNodeDType*)this; }
+    AstNodeDType* skipRefp() const override VL_MT_STABLE { return (AstNodeDType*)this; }
    AstNodeDType* skipRefToConstp() const override { return (AstNodeDType*)this; }
    AstNodeDType* skipRefToEnump() const override { return (AstNodeDType*)this; }
    // (Slow) recurses - Structure alignment 1,2,4 or 8 bytes (arrays affect this)
@@ -241,20 +239,14 @@ public:
    bool similarDType(const AstNodeDType* samep) const override {
        return this == samep;  // We don't compare members, require exact equivalence
    }
-    string name() const override { return m_name; }
+    string name() const override VL_MT_STABLE { return m_name; }
    void name(const string& flag) override { m_name = flag; }
    bool packed() const VL_MT_SAFE { return m_packed; }
    void packed(bool flag) { m_packed = flag; }
    // packed() but as don't support unpacked, presently all structs
    static bool packedUnsup() { return true; }
    void isFourstate(bool flag) { m_isFourstate = flag; }
-    bool isFourstate() const override { return m_isFourstate; }
-    void clearCache() { m_members.clear(); }
-    void repairMemberCache();
-    AstMemberDType* findMember(const string& name) const {
-        const auto it = m_members.find(name);
-        return (it == m_members.end()) ? nullptr : it->second;
-    }
+    bool isFourstate() const override VL_MT_SAFE { return m_isFourstate; }
    static int lo() { return 0; }
    int hi() const { return dtypep()->width() - 1; }  // Packed classes look like arrays
    VNumRange declRange() const { return VNumRange{hi(), lo()}; }
@@ -280,7 +272,7 @@ public:
        this->valuep(valuep);
    }
    ASTGEN_MEMBERS_AstEnumItem;
-    string name() const override { return m_name; }
+    string name() const override VL_MT_STABLE { return m_name; }
    bool maybePointedTo() const override { return true; }
    bool hasDType() const override { return true; }
    void name(const string& flag) override { m_name = flag; }
@@ -336,7 +328,7 @@ public:
    void dumpSmall(std::ostream& str) const override;
    AstNodeDType* getChildDTypep() const override { return childDTypep(); }
    AstNodeDType* getChild2DTypep() const override { return keyChildDTypep(); }
-    AstNodeDType* subDTypep() const override VL_MT_SAFE {
+    AstNodeDType* subDTypep() const override VL_MT_STABLE {
        return m_refDTypep ? m_refDTypep : childDTypep();
    }
    void refDTypep(AstNodeDType* nodep) { m_refDTypep = nodep; }
@@ -345,13 +337,13 @@ public:
    AstNodeDType* virtRefDType2p() const override { return m_keyDTypep; }
    void virtRefDType2p(AstNodeDType* nodep) override { keyDTypep(nodep); }
    //
-    AstNodeDType* keyDTypep() const VL_MT_SAFE {
+    AstNodeDType* keyDTypep() const VL_MT_STABLE {
        return m_keyDTypep ? m_keyDTypep : keyChildDTypep();
    }
    void keyDTypep(AstNodeDType* nodep) { m_keyDTypep = nodep; }
    // METHODS
-    AstBasicDType* basicp() const override VL_MT_SAFE { return nullptr; }
-    AstNodeDType* skipRefp() const override VL_MT_SAFE { return (AstNodeDType*)this; }
+    AstBasicDType* basicp() const override VL_MT_STABLE { return nullptr; }
+    AstNodeDType* skipRefp() const override VL_MT_STABLE { return (AstNodeDType*)this; }
    AstNodeDType* skipRefToConstp() const override { return (AstNodeDType*)this; }
    AstNodeDType* skipRefToEnump() const override { return (AstNodeDType*)this; }
    int widthAlignBytes() const override { return subDTypep()->widthAlignBytes(); }
@@ -401,14 +393,11 @@ public:
    ASTGEN_MEMBERS_AstBasicDType;
    void dump(std::ostream& str) const override;
    // width/widthMin/numeric compared elsewhere
-    bool same(const AstNode* samep) const override {
-        const AstBasicDType* const sp = static_cast<const AstBasicDType*>(samep);
-        return m == sp->m;
-    }
+    bool same(const AstNode* samep) const override;
    bool similarDType(const AstNodeDType* samep) const override {
        return type() == samep->type() && same(samep);
    }
-    string name() const override { return m.m_keyword.ascii(); }
+    string name() const override VL_MT_STABLE { return m.m_keyword.ascii(); }
    string prettyDTypeName() const override;
    const char* broken() const override {
        BROKEN_RTN(dtypep() != this);
@@ -423,8 +412,8 @@ public:
        }
    }
    // METHODS
-    AstBasicDType* basicp() const override VL_MT_SAFE { return (AstBasicDType*)this; }
-    AstNodeDType* skipRefp() const override VL_MT_SAFE { return (AstNodeDType*)this; }
+    AstBasicDType* basicp() const override VL_MT_STABLE { return (AstBasicDType*)this; }
+    AstNodeDType* skipRefp() const override VL_MT_STABLE { return (AstNodeDType*)this; }
    AstNodeDType* skipRefToConstp() const override { return (AstNodeDType*)this; }
    AstNodeDType* skipRefToEnump() const override { return (AstNodeDType*)this; }
    // (Slow) recurses - Structure alignment 1,2,4 or 8 bytes (arrays affect this)
@@ -440,6 +429,7 @@ public:
    bool isEvent() const VL_MT_SAFE { return keyword() == VBasicDTypeKwd::EVENT; }
    bool isTriggerVec() const VL_MT_SAFE { return keyword() == VBasicDTypeKwd::TRIGGERVEC; }
    bool isForkSync() const VL_MT_SAFE { return keyword() == VBasicDTypeKwd::FORK_SYNC; }
+    bool isProcessRef() const VL_MT_SAFE { return keyword() == VBasicDTypeKwd::PROCESS_REFERENCE; }
    bool isDelayScheduler() const VL_MT_SAFE {
        return keyword() == VBasicDTypeKwd::DELAY_SCHEDULER;
    }
@@ -467,9 +457,9 @@ public:
    inline int hi() const;
    inline int lo() const;
    inline int elements() const;
-    int left() const { return littleEndian() ? lo() : hi(); }  // How to show a declaration
-    int right() const { return littleEndian() ? hi() : lo(); }
-    inline bool littleEndian() const;
+    int left() const { return ascending() ? lo() : hi(); }  // How to show a declaration
+    int right() const { return ascending() ? hi() : lo(); }
+    inline bool ascending() const;
    bool implicit() const { return keyword() == VBasicDTypeKwd::LOGIC_IMPLICIT; }
    bool untyped() const { return keyword() == VBasicDTypeKwd::UNTYPED; }
    VNumRange declRange() const { return isRanged() ? VNumRange{left(), right()} : VNumRange{}; }
@@ -491,13 +481,13 @@ public:
    }
    ASTGEN_MEMBERS_AstBracketArrayDType;
    bool similarDType(const AstNodeDType* samep) const override { V3ERROR_NA_RETURN(false); }
-    AstNodeDType* subDTypep() const override { return childDTypep(); }
+    AstNodeDType* subDTypep() const override VL_MT_STABLE { return childDTypep(); }
    // METHODS
    // Will be removed in V3Width, which relies on this
    // being a child not a dtype pointed node
    bool maybePointedTo() const override { return false; }
-    AstBasicDType* basicp() const override VL_MT_SAFE { return nullptr; }
-    AstNodeDType* skipRefp() const override VL_MT_SAFE { return (AstNodeDType*)this; }
+    AstBasicDType* basicp() const override VL_MT_STABLE { return nullptr; }
+    AstNodeDType* skipRefp() const override VL_MT_STABLE { return (AstNodeDType*)this; }
    AstNodeDType* skipRefToConstp() const override { return (AstNodeDType*)this; }
    AstNodeDType* skipRefToEnump() const override { return (AstNodeDType*)this; }
    int widthAlignBytes() const override { V3ERROR_NA_RETURN(0); }
@@ -530,19 +520,19 @@ public:
    }
    void dump(std::ostream& str = std::cout) const override;
    void dumpSmall(std::ostream& str) const override;
-    string name() const override;
-    AstBasicDType* basicp() const override VL_MT_SAFE { return nullptr; }
-    AstNodeDType* skipRefp() const override VL_MT_SAFE { return (AstNodeDType*)this; }
+    string name() const override VL_MT_STABLE;
+    AstBasicDType* basicp() const override VL_MT_STABLE { return nullptr; }
+    AstNodeDType* skipRefp() const override VL_MT_STABLE { return (AstNodeDType*)this; }
    AstNodeDType* skipRefToConstp() const override { return (AstNodeDType*)this; }
    AstNodeDType* skipRefToEnump() const override { return (AstNodeDType*)this; }
    int widthAlignBytes() const override { return 0; }
    int widthTotalBytes() const override { return 0; }
    AstNodeDType* virtRefDTypep() const override { return nullptr; }
    void virtRefDTypep(AstNodeDType* nodep) override {}
-    AstNodeDType* subDTypep() const override { return nullptr; }
+    AstNodeDType* subDTypep() const override VL_MT_SAFE { return nullptr; }
    AstNodeModule* classOrPackagep() const { return m_classOrPackagep; }
    void classOrPackagep(AstNodeModule* nodep) { m_classOrPackagep = nodep; }
-    AstClass* classp() const { return m_classp; }
+    AstClass* classp() const VL_MT_STABLE { return m_classp; }
    void classp(AstClass* nodep) { m_classp = nodep; }
    bool isCompound() const override { return true; }
 };
@@ -578,13 +568,15 @@ public:
        return skipRefp()->similarDType(samep->skipRefp());
    }
    AstNodeDType* getChildDTypep() const override { return childDTypep(); }
-    AstNodeDType* subDTypep() const override { return m_refDTypep ? m_refDTypep : childDTypep(); }
+    AstNodeDType* subDTypep() const override VL_MT_STABLE {
+        return m_refDTypep ? m_refDTypep : childDTypep();
+    }
    void refDTypep(AstNodeDType* nodep) { m_refDTypep = nodep; }
    AstNodeDType* virtRefDTypep() const override { return m_refDTypep; }
    void virtRefDTypep(AstNodeDType* nodep) override { refDTypep(nodep); }
    // METHODS
-    AstBasicDType* basicp() const override VL_MT_SAFE { return subDTypep()->basicp(); }
-    AstNodeDType* skipRefp() const override VL_MT_SAFE { return subDTypep()->skipRefp(); }
+    AstBasicDType* basicp() const override VL_MT_STABLE { return subDTypep()->basicp(); }
+    AstNodeDType* skipRefp() const override VL_MT_STABLE { return subDTypep()->skipRefp(); }
    AstNodeDType* skipRefToConstp() const override { return (AstNodeDType*)this; }
    AstNodeDType* skipRefToEnump() const override { return subDTypep()->skipRefToEnump(); }
    int widthAlignBytes() const override { return subDTypep()->widthAlignBytes(); }
@@ -625,18 +617,20 @@ public:
        return type() == samep->type() && same(samep);
    }
    AstNodeDType* getChildDTypep() const override { return childDTypep(); }
-    AstNodeDType* subDTypep() const override { return dtypep() ? dtypep() : childDTypep(); }
+    AstNodeDType* subDTypep() const override VL_MT_STABLE {
+        return dtypep() ? dtypep() : childDTypep();
+    }
    void* containerp() const { return m_containerp; }
    // METHODS
    // op1 = Range of variable
    AstNodeDType* dtypeSkipRefp() const { return dtypep()->skipRefp(); }
-    AstBasicDType* basicp() const override VL_MT_SAFE { return subDTypep()->basicp(); }
-    AstNodeDType* skipRefp() const override VL_MT_SAFE { return (AstNodeDType*)this; }
+    AstBasicDType* basicp() const override VL_MT_STABLE { return subDTypep()->basicp(); }
+    AstNodeDType* skipRefp() const override VL_MT_STABLE { return (AstNodeDType*)this; }
    AstNodeDType* skipRefToConstp() const override { return (AstNodeDType*)this; }
    AstNodeDType* skipRefToEnump() const override { return (AstNodeDType*)this; }
    int widthAlignBytes() const override { return dtypep()->widthAlignBytes(); }
    int widthTotalBytes() const override { return dtypep()->widthTotalBytes(); }
-    string name() const override { return m_name; }
+    string name() const override VL_MT_STABLE { return m_name; }
    void name(const string& flag) override { m_name = flag; }
    bool isCompound() const override { return false; }
 };
@@ -679,15 +673,15 @@ public:
    string prettyDTypeName() const override;
    void dumpSmall(std::ostream& str) const override;
    AstNodeDType* getChildDTypep() const override { return childDTypep(); }
-    AstNodeDType* subDTypep() const override VL_MT_SAFE {
+    AstNodeDType* subDTypep() const override VL_MT_STABLE {
        return m_refDTypep ? m_refDTypep : childDTypep();
    }
    void refDTypep(AstNodeDType* nodep) { m_refDTypep = nodep; }
    AstNodeDType* virtRefDTypep() const override { return m_refDTypep; }
    void virtRefDTypep(AstNodeDType* nodep) override { refDTypep(nodep); }
    // METHODS
-    AstBasicDType* basicp() const override VL_MT_SAFE { return nullptr; }
-    AstNodeDType* skipRefp() const override VL_MT_SAFE { return (AstNodeDType*)this; }
+    AstBasicDType* basicp() const override VL_MT_STABLE { return nullptr; }
+    AstNodeDType* skipRefp() const override VL_MT_STABLE { return (AstNodeDType*)this; }
    AstNodeDType* skipRefToConstp() const override { return (AstNodeDType*)this; }
    AstNodeDType* skipRefToEnump() const override { return (AstNodeDType*)this; }
    int widthAlignBytes() const override { return subDTypep()->widthAlignBytes(); }
@@ -706,13 +700,13 @@ public:
    bool hasDType() const override { return true; }
    bool maybePointedTo() const override { return true; }
    bool undead() const override { return true; }
-    AstNodeDType* subDTypep() const override { return nullptr; }
+    AstNodeDType* subDTypep() const override VL_MT_SAFE { return nullptr; }
    AstNodeDType* virtRefDTypep() const override { return nullptr; }
    void virtRefDTypep(AstNodeDType* nodep) override {}
    bool similarDType(const AstNodeDType* samep) const override { return this == samep; }
-    AstBasicDType* basicp() const override VL_MT_SAFE { return nullptr; }
+    AstBasicDType* basicp() const override VL_MT_STABLE { return nullptr; }
    // cppcheck-suppress csyleCast
-    AstNodeDType* skipRefp() const override VL_MT_SAFE { return (AstNodeDType*)this; }
+    AstNodeDType* skipRefp() const override VL_MT_STABLE { return (AstNodeDType*)this; }
    // cppcheck-suppress csyleCast
    AstNodeDType* skipRefToConstp() const override { return (AstNodeDType*)this; }
    // cppcheck-suppress csyleCast
@@ -756,17 +750,19 @@ public:
    }
    bool similarDType(const AstNodeDType* samep) const override { return this == samep; }
    AstNodeDType* getChildDTypep() const override { return childDTypep(); }
-    AstNodeDType* subDTypep() const override { return m_refDTypep ? m_refDTypep : childDTypep(); }
+    AstNodeDType* subDTypep() const override VL_MT_STABLE {
+        return m_refDTypep ? m_refDTypep : childDTypep();
+    }
    void refDTypep(AstNodeDType* nodep) { m_refDTypep = nodep; }
    AstNodeDType* virtRefDTypep() const override { return m_refDTypep; }
    void virtRefDTypep(AstNodeDType* nodep) override { refDTypep(nodep); }
-    string name() const override { return m_name; }
+    string name() const override VL_MT_STABLE { return m_name; }
    void name(const string& flag) override { m_name = flag; }
    void dump(std::ostream& str = std::cout) const override;
    void dumpSmall(std::ostream& str) const override;
    // METHODS
-    AstBasicDType* basicp() const override VL_MT_SAFE { return subDTypep()->basicp(); }
-    AstNodeDType* skipRefp() const override VL_MT_SAFE { return subDTypep()->skipRefp(); }
+    AstBasicDType* basicp() const override VL_MT_STABLE { return subDTypep()->basicp(); }
+    AstNodeDType* skipRefp() const override VL_MT_STABLE { return subDTypep()->skipRefp(); }
    AstNodeDType* skipRefToConstp() const override { return subDTypep()->skipRefToConstp(); }
    // cppcheck-suppress csyleCast
    AstNodeDType* skipRefToEnump() const override { return (AstNodeDType*)this; }
@@ -818,8 +814,8 @@ public:
    void dump(std::ostream& str = std::cout) const override;
    void dumpSmall(std::ostream& str) const override;
    void cloneRelink() override;
-    AstBasicDType* basicp() const override VL_MT_SAFE { return nullptr; }
-    AstNodeDType* skipRefp() const override VL_MT_SAFE { return (AstNodeDType*)this; }
+    AstBasicDType* basicp() const override VL_MT_STABLE { return nullptr; }
+    AstNodeDType* skipRefp() const override VL_MT_STABLE { return (AstNodeDType*)this; }
    AstNodeDType* skipRefToConstp() const override { return (AstNodeDType*)this; }
    AstNodeDType* skipRefToEnump() const override { return (AstNodeDType*)this; }
    bool similarDType(const AstNodeDType* samep) const override { return this == samep; }
@@ -872,7 +868,7 @@ public:
    }
    ASTGEN_MEMBERS_AstMemberDType;
    void dumpSmall(std::ostream& str) const override;
-    string name() const override { return m_name; }  // * = Var name
+    string name() const override VL_MT_STABLE { return m_name; }  // * = Var name
    bool hasDType() const override { return true; }
    bool maybePointedTo() const override { return true; }
    const char* broken() const override {
@@ -883,7 +879,10 @@ public:
        if (m_refDTypep && m_refDTypep->clonep()) m_refDTypep = m_refDTypep->clonep();
    }
    AstNodeDType* getChildDTypep() const override { return childDTypep(); }
-    AstNodeDType* subDTypep() const override { return m_refDTypep ? m_refDTypep : childDTypep(); }
+    AstNodeUOrStructDType* getChildStructp() const;
+    AstNodeDType* subDTypep() const override VL_MT_STABLE {
+        return m_refDTypep ? m_refDTypep : childDTypep();
+    }
    void refDTypep(AstNodeDType* nodep) { m_refDTypep = nodep; }
    AstNodeDType* virtRefDTypep() const override { return m_refDTypep; }
    void virtRefDTypep(AstNodeDType* nodep) override { refDTypep(nodep); }
@@ -891,10 +890,10 @@ public:
    //
    // (Slow) recurse down to find basic data type (Note don't need virtual -
    // AstVar isn't a NodeDType)
-    AstBasicDType* basicp() const override VL_MT_SAFE { return subDTypep()->basicp(); }
+    AstBasicDType* basicp() const override VL_MT_STABLE { return subDTypep()->basicp(); }
    // op1 = Range of variable (Note don't need virtual - AstVar isn't a NodeDType)
    AstNodeDType* dtypeSkipRefp() const { return subDTypep()->skipRefp(); }
-    AstNodeDType* skipRefp() const override VL_MT_SAFE { return subDTypep()->skipRefp(); }
+    AstNodeDType* skipRefp() const override VL_MT_STABLE { return subDTypep()->skipRefp(); }
    AstNodeDType* skipRefToConstp() const override { return subDTypep()->skipRefToConstp(); }
    AstNodeDType* skipRefToEnump() const override { return subDTypep()->skipRefToEnump(); }
    // (Slow) recurses - Structure alignment 1,2,4 or 8 bytes (arrays affect this)
@@ -931,9 +930,11 @@ public:
    ASTGEN_MEMBERS_AstParamTypeDType;
    void dump(std::ostream& str = std::cout) const override;
    AstNodeDType* getChildDTypep() const override { return childDTypep(); }
-    AstNodeDType* subDTypep() const override { return dtypep() ? dtypep() : childDTypep(); }
-    AstBasicDType* basicp() const override VL_MT_SAFE { return subDTypep()->basicp(); }
-    AstNodeDType* skipRefp() const override VL_MT_SAFE { return subDTypep()->skipRefp(); }
+    AstNodeDType* subDTypep() const override VL_MT_STABLE {
+        return dtypep() ? dtypep() : childDTypep();
+    }
+    AstBasicDType* basicp() const override VL_MT_STABLE { return subDTypep()->basicp(); }
+    AstNodeDType* skipRefp() const override VL_MT_STABLE { return subDTypep()->skipRefp(); }
    AstNodeDType* skipRefToConstp() const override { return subDTypep()->skipRefToConstp(); }
    AstNodeDType* skipRefToEnump() const override { return subDTypep()->skipRefToEnump(); }
    bool similarDType(const AstNodeDType* samep) const override {
@@ -944,7 +945,7 @@ public:
    int widthAlignBytes() const override { return dtypep()->widthAlignBytes(); }
    int widthTotalBytes() const override { return dtypep()->widthTotalBytes(); }
    // METHODS
-    string name() const override { return m_name; }
+    string name() const override VL_MT_STABLE { return m_name; }
    bool maybePointedTo() const override { return true; }
    bool hasDType() const override { return true; }
    void name(const string& flag) override { m_name = flag; }
@@ -967,8 +968,8 @@ public:
    AstNodeDType* dtypep() const { return nullptr; }
    // METHODS
    bool similarDType(const AstNodeDType* samep) const override { return this == samep; }
-    AstBasicDType* basicp() const override VL_MT_SAFE { return nullptr; }
-    AstNodeDType* skipRefp() const override VL_MT_SAFE { return nullptr; }
+    AstBasicDType* basicp() const override VL_MT_STABLE { return nullptr; }
+    AstNodeDType* skipRefp() const override VL_MT_STABLE { return nullptr; }
    // cppcheck-suppress csyleCast
    AstNodeDType* skipRefToConstp() const override { return (AstNodeDType*)this; }
    // cppcheck-suppress csyleCast
@@ -1022,17 +1023,17 @@ public:
    void dumpSmall(std::ostream& str) const override;
    string prettyDTypeName() const override;
    AstNodeDType* getChildDTypep() const override { return childDTypep(); }
-    AstNodeDType* subDTypep() const override VL_MT_SAFE {
+    AstNodeDType* subDTypep() const override VL_MT_STABLE {
        return m_refDTypep ? m_refDTypep : childDTypep();
    }
    void refDTypep(AstNodeDType* nodep) { m_refDTypep = nodep; }
-    inline int boundConst() const;
+    inline int boundConst() const VL_MT_STABLE;
    AstNodeDType* virtRefDTypep() const override { return m_refDTypep; }
    void virtRefDTypep(AstNodeDType* nodep) override { refDTypep(nodep); }
    // METHODS
-    AstBasicDType* basicp() const override VL_MT_SAFE { return nullptr; }
+    AstBasicDType* basicp() const override VL_MT_STABLE { return nullptr; }
    // cppcheck-suppress csyleCast
-    AstNodeDType* skipRefp() const override VL_MT_SAFE { return (AstNodeDType*)this; }
+    AstNodeDType* skipRefp() const override VL_MT_STABLE { return (AstNodeDType*)this; }
    // cppcheck-suppress csyleCast
    AstNodeDType* skipRefToConstp() const override { return (AstNodeDType*)this; }
    // cppcheck-suppress csyleCast
@@ -1052,7 +1053,7 @@ private:
    // Post-width typedefs are removed and point to type directly
    AstNodeDType* m_refDTypep = nullptr;  // data type pointed to, BELOW the AstTypedef
    string m_name;  // Name of an AstTypedef
-    AstNodeModule* m_classOrPackagep = nullptr;  // Package hierarchy
+    AstNodeModule* m_classOrPackagep = nullptr;  // Class/package in which it was defined
 public:
    AstRefDType(FileLine* fl, const string& name)
        : ASTGEN_SUPER_RefDType(fl)
@@ -1067,6 +1068,7 @@ public:
    AstRefDType(FileLine* fl, FlagTypeOfExpr, AstNode* typeofp)
        : ASTGEN_SUPER_RefDType(fl) {
        this->typeofp(typeofp);
+        if (AstNodeDType* const dtp = VN_CAST(typeofp, NodeDType)) refDTypep(dtp);
    }
    ASTGEN_MEMBERS_AstRefDType;
    // METHODS
@@ -1082,15 +1084,15 @@ public:
    }
    void dump(std::ostream& str = std::cout) const override;
    void dumpSmall(std::ostream& str) const override;
-    string name() const override { return m_name; }
+    string name() const override VL_MT_STABLE { return m_name; }
    string prettyDTypeName() const override {
        return subDTypep() ? prettyName(subDTypep()->name()) : prettyName();
    }
-    AstBasicDType* basicp() const override VL_MT_SAFE {
+    AstBasicDType* basicp() const override VL_MT_STABLE {
        return subDTypep() ? subDTypep()->basicp() : nullptr;
    }
-    AstNodeDType* subDTypep() const override;
-    AstNodeDType* skipRefp() const override VL_MT_SAFE {
+    AstNodeDType* subDTypep() const override VL_MT_STABLE;
+    AstNodeDType* skipRefp() const override VL_MT_STABLE {
        // Skip past both the Ref and the Typedef
        if (subDTypep()) {
            return subDTypep()->skipRefp();
@@ -1119,9 +1121,9 @@ public:
    int widthTotalBytes() const override { return dtypeSkipRefp()->widthTotalBytes(); }
    void name(const string& flag) override { m_name = flag; }
    AstNodeDType* dtypeSkipRefp() const { return subDTypep()->skipRefp(); }
-    AstTypedef* typedefp() const { return m_typedefp; }
+    AstTypedef* typedefp() const VL_MT_SAFE { return m_typedefp; }
    void typedefp(AstTypedef* nodep) { m_typedefp = nodep; }
-    AstNodeDType* refDTypep() const { return m_refDTypep; }
+    AstNodeDType* refDTypep() const VL_MT_SAFE { return m_refDTypep; }
    void refDTypep(AstNodeDType* nodep) { m_refDTypep = nodep; }
    AstNodeDType* virtRefDTypep() const override { return refDTypep(); }
    void virtRefDTypep(AstNodeDType* nodep) override { refDTypep(nodep); }
@@ -1163,19 +1165,49 @@ public:
    void dumpSmall(std::ostream& str) const override;
    AstNodeDType* getChildDTypep() const override { return childDTypep(); }
    // op1 = Range of variable
-    AstNodeDType* subDTypep() const override { return m_refDTypep ? m_refDTypep : childDTypep(); }
+    AstNodeDType* subDTypep() const override VL_MT_STABLE {
+        return m_refDTypep ? m_refDTypep : childDTypep();
+    }
    void refDTypep(AstNodeDType* nodep) { m_refDTypep = nodep; }
    AstNodeDType* virtRefDTypep() const override { return m_refDTypep; }
    void virtRefDTypep(AstNodeDType* nodep) override { refDTypep(nodep); }
    // METHODS
-    AstBasicDType* basicp() const override { return subDTypep()->basicp(); }
-    AstNodeDType* skipRefp() const override { return (AstNodeDType*)this; }
+    AstBasicDType* basicp() const override VL_MT_STABLE { return subDTypep()->basicp(); }
+    AstNodeDType* skipRefp() const override VL_MT_STABLE { return (AstNodeDType*)this; }
    AstNodeDType* skipRefToConstp() const override { return (AstNodeDType*)this; }
    AstNodeDType* skipRefToEnump() const override { return (AstNodeDType*)this; }
    int widthAlignBytes() const override { return sizeof(std::map<std::string, std::string>); }
    int widthTotalBytes() const override { return sizeof(std::map<std::string, std::string>); }
    bool isCompound() const override { return true; }
 };
+class AstStreamDType final : public AstNodeDType {
+    // Stream data type, used only as data type of stream operations
+    // Should behave like AstPackArrayDType, but it doesn't have a size
+public:
+    explicit AstStreamDType(FileLine* fl)
+        : ASTGEN_SUPER_StreamDType(fl) {
+        dtypep(this);
+    }
+    ASTGEN_MEMBERS_AstStreamDType;
+    void dumpSmall(std::ostream& str) const override;
+    bool hasDType() const override { return true; }
+    bool maybePointedTo() const override { return true; }
+    bool undead() const override { return true; }
+    AstNodeDType* subDTypep() const override VL_MT_SAFE { return nullptr; }
+    AstNodeDType* virtRefDTypep() const override { return nullptr; }
+    void virtRefDTypep(AstNodeDType* nodep) override {}
+    bool similarDType(const AstNodeDType* samep) const override { return this == samep; }
+    AstBasicDType* basicp() const override VL_MT_STABLE { return nullptr; }
+    // cppcheck-suppress csyleCast
+    AstNodeDType* skipRefp() const override VL_MT_STABLE { return (AstNodeDType*)this; }
+    // cppcheck-suppress csyleCast
+    AstNodeDType* skipRefToConstp() const override { return (AstNodeDType*)this; }
+    // cppcheck-suppress csyleCast
+    AstNodeDType* skipRefToEnump() const override { return (AstNodeDType*)this; }
+    int widthAlignBytes() const override { return 1; }
+    int widthTotalBytes() const override { return 1; }
+    bool isCompound() const override { return false; }
+};
 class AstUnsizedArrayDType final : public AstNodeDType {
    // Unsized/open-range Array data type, ie "some_dtype var_name []"
    // @astgen op1 := childDTypep : Optional[AstNodeDType] // moved to refDTypep() in V3Width
@@ -1201,13 +1233,15 @@ public:
    bool similarDType(const AstNodeDType* samep) const override;
    void dumpSmall(std::ostream& str) const override;
    AstNodeDType* getChildDTypep() const override { return childDTypep(); }
-    AstNodeDType* subDTypep() const override { return m_refDTypep ? m_refDTypep : childDTypep(); }
+    AstNodeDType* subDTypep() const override VL_MT_STABLE {
+        return m_refDTypep ? m_refDTypep : childDTypep();
+    }
    void refDTypep(AstNodeDType* nodep) { m_refDTypep = nodep; }
    AstNodeDType* virtRefDTypep() const override { return m_refDTypep; }
    void virtRefDTypep(AstNodeDType* nodep) override { refDTypep(nodep); }
    // METHODS
-    AstBasicDType* basicp() const override VL_MT_SAFE { return subDTypep()->basicp(); }
-    AstNodeDType* skipRefp() const override VL_MT_SAFE { return (AstNodeDType*)this; }
+    AstBasicDType* basicp() const override VL_MT_STABLE { return subDTypep()->basicp(); }
+    AstNodeDType* skipRefp() const override VL_MT_STABLE { return (AstNodeDType*)this; }
    AstNodeDType* skipRefToConstp() const override { return (AstNodeDType*)this; }
    AstNodeDType* skipRefToEnump() const override { return (AstNodeDType*)this; }
    int widthAlignBytes() const override { return subDTypep()->widthAlignBytes(); }
@@ -1226,13 +1260,13 @@ public:
    bool hasDType() const override { return true; }
    bool maybePointedTo() const override { return true; }
    bool undead() const override { return true; }
-    AstNodeDType* subDTypep() const override { return nullptr; }
+    AstNodeDType* subDTypep() const override VL_MT_SAFE { return nullptr; }
    AstNodeDType* virtRefDTypep() const override { return nullptr; }
    void virtRefDTypep(AstNodeDType* nodep) override {}
    bool similarDType(const AstNodeDType* samep) const override { return this == samep; }
-    AstBasicDType* basicp() const override VL_MT_SAFE { return nullptr; }
+    AstBasicDType* basicp() const override VL_MT_STABLE { return nullptr; }
    // cppcheck-suppress csyleCast
-    AstNodeDType* skipRefp() const override VL_MT_SAFE { return (AstNodeDType*)this; }
+    AstNodeDType* skipRefp() const override VL_MT_STABLE { return (AstNodeDType*)this; }
    // cppcheck-suppress csyleCast
    AstNodeDType* skipRefToConstp() const override { return (AstNodeDType*)this; }
    // cppcheck-suppress csyleCast
@@ -1266,15 +1300,15 @@ public:
    bool similarDType(const AstNodeDType* samep) const override;
    void dumpSmall(std::ostream& str) const override;
    AstNodeDType* getChildDTypep() const override { return childDTypep(); }
-    AstNodeDType* subDTypep() const override VL_MT_SAFE {
+    AstNodeDType* subDTypep() const override VL_MT_STABLE {
        return m_refDTypep ? m_refDTypep : childDTypep();
    }
    void refDTypep(AstNodeDType* nodep) { m_refDTypep = nodep; }
    AstNodeDType* virtRefDTypep() const override { return m_refDTypep; }
    void virtRefDTypep(AstNodeDType* nodep) override { refDTypep(nodep); }
    // METHODS
-    AstBasicDType* basicp() const override VL_MT_SAFE { return subDTypep()->basicp(); }
-    AstNodeDType* skipRefp() const override VL_MT_SAFE { return (AstNodeDType*)this; }
+    AstBasicDType* basicp() const override VL_MT_STABLE { return subDTypep()->basicp(); }
+    AstNodeDType* skipRefp() const override VL_MT_STABLE { return (AstNodeDType*)this; }
    AstNodeDType* skipRefToConstp() const override { return (AstNodeDType*)this; }
    AstNodeDType* skipRefToEnump() const override { return (AstNodeDType*)this; }
    int widthAlignBytes() const override { return sizeof(std::map<std::string, std::string>); }
@@ -214,7 +214,7 @@ class AstNodeFTaskRef VL_NOT_FINAL : public AstNodeExpr {
    // @astgen op3 := pinsp : List[AstNodeExpr]
    // @astgen op4 := scopeNamep : Optional[AstScopeName]
    AstNodeFTask* m_taskp = nullptr;  // [AfterLink] Pointer to task referenced
-    AstNodeModule* m_classOrPackagep = nullptr;  // Package hierarchy
+    AstNodeModule* m_classOrPackagep = nullptr;  // Class/package of the task
    string m_name;  // Name of variable
    string m_dotted;  // Dotted part of scope the name()ed task/func is under or ""
    string m_inlinedDots;  // Dotted hierarchy flattened out
@@ -236,7 +236,7 @@ public:
    const char* broken() const override;
    void cloneRelink() override;
    void dump(std::ostream& str = std::cout) const override;
-    string name() const override { return m_name; }  // * = Var name
+    string name() const override VL_MT_STABLE { return m_name; }  // * = Var name
    bool isGateOptimizable() const override;
    string dotted() const { return m_dotted; }  // * = Scope name or ""
    string inlinedDots() const { return m_inlinedDots; }
@@ -322,7 +322,7 @@ public:
    ASTGEN_MEMBERS_AstNodeTermop;
    // Know no children, and hot function, so skip iterator for speed
    // cppcheck-suppress functionConst
-    void iterateChildren(VNVisitor& v) {}
+    void iterateChildren(VNVisitorConst& v) {}
    void dump(std::ostream& str) const override;
 };
 class AstNodeTriop VL_NOT_FINAL : public AstNodeExpr {
@@ -360,14 +360,8 @@ class AstNodeCond VL_NOT_FINAL : public AstNodeTriop {
    // @astgen alias op2 := thenp
    // @astgen alias op3 := elsep
 protected:
-    AstNodeCond(VNType t, FileLine* fl, AstNodeExpr* condp, AstNodeExpr* thenp, AstNodeExpr* elsep)
-        : AstNodeTriop{t, fl, condp, thenp, elsep} {
-        if (thenp) {
-            dtypeFrom(thenp);
-        } else if (elsep) {
-            dtypeFrom(elsep);
-        }
-    }
+    AstNodeCond(VNType t, FileLine* fl, AstNodeExpr* condp, AstNodeExpr* thenp,
+                AstNodeExpr* elsep);

 public:
    ASTGEN_MEMBERS_AstNodeCond;
@@ -449,21 +443,19 @@ class AstNodeVarRef VL_NOT_FINAL : public AstNodeExpr {
    VAccess m_access;  // Left hand side assignment
    AstVar* m_varp;  // [AfterLink] Pointer to variable itself
    AstVarScope* m_varScopep = nullptr;  // Varscope for hierarchy
-    AstNodeModule* m_classOrPackagep = nullptr;  // Package hierarchy
-    string m_name;  // Name of variable
-    string m_selfPointer;  // Output code object pointer (e.g.: 'this')
-
+    AstNodeModule* m_classOrPackagep = nullptr;  // Class/package of the variable
+    VSelfPointerText m_selfPointer
+        = VSelfPointerText{VSelfPointerText::Empty()};  // Output code object
+                                                        // pointer (e.g.: 'this')
 protected:
-    AstNodeVarRef(VNType t, FileLine* fl, const string& name, const VAccess& access)
+    AstNodeVarRef(VNType t, FileLine* fl, const VAccess& access)
        : AstNodeExpr{t, fl}
-        , m_access{access}
-        , m_name{name} {
+        , m_access{access} {
        varp(nullptr);
    }
-    AstNodeVarRef(VNType t, FileLine* fl, const string& name, AstVar* varp, const VAccess& access)
+    AstNodeVarRef(VNType t, FileLine* fl, AstVar* varp, const VAccess& access)
        : AstNodeExpr{t, fl}
-        , m_access{access}
-        , m_name{name} {
+        , m_access{access} {
        // May have varp==nullptr
        this->varp(varp);
    }
@@ -474,8 +466,6 @@ public:
    const char* broken() const override;
    int instrCount() const override { return widthInstrs(); }
    void cloneRelink() override;
-    string name() const override { return m_name; }  // * = Var name
-    void name(const string& name) override { m_name = name; }
    VAccess access() const { return m_access; }
    void access(const VAccess& flag) { m_access = flag; }  // Avoid using this; Set in constructor
    AstVar* varp() const { return m_varp; }  // [After Link] Pointer to variable
@@ -485,14 +475,16 @@ public:
    }
    AstVarScope* varScopep() const { return m_varScopep; }
    void varScopep(AstVarScope* varscp) { m_varScopep = varscp; }
-    string selfPointer() const { return m_selfPointer; }
-    void selfPointer(const string& value) { m_selfPointer = value; }
-    string selfPointerProtect(bool useSelfForThis) const;
+    const VSelfPointerText& selfPointer() const { return m_selfPointer; }
+    void selfPointer(const VSelfPointerText& selfPointer) { m_selfPointer = selfPointer; }
+    string selfPointerProtect(bool useSelfForThis) const {
+        return selfPointer().protect(useSelfForThis, protect());
+    }
    AstNodeModule* classOrPackagep() const { return m_classOrPackagep; }
    void classOrPackagep(AstNodeModule* nodep) { m_classOrPackagep = nodep; }
    // Know no children, and hot function, so skip iterator for speed
    // cppcheck-suppress functionConst
-    void iterateChildren(VNVisitor& v) {}
+    void iterateChildren(VNVisitorConst& v) {}
 };

 // === Concrete node types =====================================================
@@ -532,7 +524,7 @@ public:
    }
    ASTGEN_MEMBERS_AstArg;
    bool hasDType() const override { return false; }
-    string name() const override { return m_name; }  // * = Pin name, ""=go by number
+    string name() const override VL_MT_STABLE { return m_name; }  // * = Pin name, ""=go by number
    void name(const string& name) override { m_name = name; }
    bool emptyConnectNoNext() const { return !exprp() && name() == "" && !nextp(); }

@@ -593,35 +585,29 @@ class AstCMethodHard final : public AstNodeExpr {
    string m_name;  // Name of method
    bool m_pure = false;  // Pure optimizable
 public:
-    AstCMethodHard(FileLine* fl, AstNodeExpr* fromp, VFlagChildDType, const string& name,
-                   AstNodeExpr* pinsp = nullptr)
-        : ASTGEN_SUPER_CMethodHard(fl)
-        , m_name{name} {
-        // TODO: this constructor is exactly the same as the other, bar the ignored tag argument
-        this->fromp(fromp);
-        this->addPinsp(pinsp);
-        dtypep(nullptr);  // V3Width will resolve
-    }
    AstCMethodHard(FileLine* fl, AstNodeExpr* fromp, const string& name,
                   AstNodeExpr* pinsp = nullptr)
        : ASTGEN_SUPER_CMethodHard(fl)
        , m_name{name} {
        this->fromp(fromp);
        this->addPinsp(pinsp);
+        setPurity();
    }
    ASTGEN_MEMBERS_AstCMethodHard;
-    string name() const override { return m_name; }  // * = Var name
+    string name() const override VL_MT_STABLE { return m_name; }  // * = Var name
    void name(const string& name) override { m_name = name; }
    bool same(const AstNode* samep) const override {
        const AstCMethodHard* asamep = static_cast<const AstCMethodHard*>(samep);
        return (m_name == asamep->m_name);
    }
    bool isPure() const override { return m_pure; }
-    void pure(bool flag) { m_pure = flag; }
    int instrCount() const override;
    string emitVerilog() override { V3ERROR_NA_RETURN(""); }
    string emitC() override { V3ERROR_NA_RETURN(""); }
    bool cleanOut() const override { return true; }
+
+private:
+    void setPurity();
 };
 class AstCast final : public AstNodeExpr {
    // Cast to appropriate data type
@@ -644,7 +630,7 @@ public:
    string emitC() override { V3ERROR_NA_RETURN(""); }
    bool cleanOut() const override { V3ERROR_NA_RETURN(true); }
    AstNodeDType* getChildDTypep() const override { return childDTypep(); }
-    AstNodeDType* subDTypep() const { return dtypep() ? dtypep() : childDTypep(); }
+    AstNodeDType* subDTypep() const VL_MT_STABLE { return dtypep() ? dtypep() : childDTypep(); }
 };
 class AstCastParse final : public AstNodeExpr {
    // Cast to appropriate type, where we haven't determined yet what the data type is
@@ -689,7 +675,7 @@ public:
    }
    ASTGEN_MEMBERS_AstCellArrayRef;
    // ACCESSORS
-    string name() const override { return m_name; }  // * = Array name
+    string name() const override VL_MT_STABLE { return m_name; }  // * = Array name

    string emitVerilog() override { V3ERROR_NA_RETURN(""); }
    string emitC() override { V3ERROR_NA_RETURN(""); }
@@ -710,7 +696,7 @@ public:
    }
    ASTGEN_MEMBERS_AstCellRef;
    // ACCESSORS
-    string name() const override { return m_name; }  // * = Array name
+    string name() const override VL_MT_STABLE { return m_name; }  // * = Array name

    string emitVerilog() override { V3ERROR_NA_RETURN(""); }
    string emitC() override { V3ERROR_NA_RETURN(""); }
@@ -721,7 +707,7 @@ class AstClassOrPackageRef final : public AstNodeExpr {
 private:
    string m_name;
    // Node not NodeModule to appease some early parser usage
-    AstNode* m_classOrPackageNodep;  // Package hierarchy
+    AstNode* m_classOrPackageNodep;  // Pointer to class/package referenced
 public:
    AstClassOrPackageRef(FileLine* fl, const string& name, AstNode* classOrPackageNodep,
                         AstPin* paramsp)
@@ -746,7 +732,7 @@ public:
                == static_cast<const AstClassOrPackageRef*>(samep)->m_classOrPackageNodep);
    }
    void dump(std::ostream& str = std::cout) const override;
-    string name() const override { return m_name; }  // * = Var name
+    string name() const override VL_MT_STABLE { return m_name; }  // * = Var name
    AstNode* classOrPackageNodep() const { return m_classOrPackageNodep; }
    void classOrPackageNodep(AstNode* nodep) { m_classOrPackageNodep = nodep; }
    AstNodeModule* classOrPackagep() const;
@@ -975,6 +961,20 @@ public:
        , m_num(this, 1, on) {
        dtypeSetBit();
    }
+    class All0 {};
+    AstConst(FileLine* fl, All0)
+        : ASTGEN_SUPER_Const(fl)
+        , m_num(this, "'0") {
+        initWithNumber();
+        fl->warnOff(V3ErrorCode::NEWERSTD, true);
+    }
+    class All1 {};
+    AstConst(FileLine* fl, All1)
+        : ASTGEN_SUPER_Const(fl)
+        , m_num(this, "'1") {
+        initWithNumber();
+        fl->warnOff(V3ErrorCode::NEWERSTD, true);
+    }
    class Null {};
    AstConst(FileLine* fl, Null)
        : ASTGEN_SUPER_Const(fl)
@@ -990,7 +990,7 @@ public:
        initWithNumber();
    }
    ASTGEN_MEMBERS_AstConst;
-    string name() const override { return num().ascii(); }  // * = Value
+    string name() const override VL_MT_STABLE { return num().ascii(); }  // * = Value
    const V3Number& num() const VL_MT_SAFE { return m_num; }  // * = Value
    V3Number& num() { return m_num; }  // * = Value
    uint32_t toUInt() const { return num().toUInt(); }
@@ -1010,6 +1010,34 @@ public:
    // May return nullptr on parse failure.
    static AstConst* parseParamLiteral(FileLine* fl, const string& literal);
 };
+class AstCvtDynArrayToPacked final : public AstNodeExpr {
+    // Cast from dynamic queue data type to packed array
+    // @astgen op1 := fromp : AstNodeExpr
+public:
+    AstCvtDynArrayToPacked(FileLine* fl, AstNodeExpr* fromp, AstNodeDType* dtp)
+        : ASTGEN_SUPER_CvtDynArrayToPacked(fl) {
+        this->fromp(fromp);
+        dtypeFrom(dtp);
+    }
+    ASTGEN_MEMBERS_AstCvtDynArrayToPacked;
+    string emitVerilog() override { V3ERROR_NA_RETURN(""); }
+    string emitC() override { V3ERROR_NA_RETURN(""); }
+    bool cleanOut() const override { return true; }
+};
+class AstCvtPackedToDynArray final : public AstNodeExpr {
+    // Cast from packed array to dynamic queue data type
+    // @astgen op1 := fromp : AstNodeExpr
+public:
+    AstCvtPackedToDynArray(FileLine* fl, AstNodeExpr* fromp, AstNodeDType* dtp)
+        : ASTGEN_SUPER_CvtPackedToDynArray(fl) {
+        this->fromp(fromp);
+        dtypeFrom(dtp);
+    }
+    ASTGEN_MEMBERS_AstCvtPackedToDynArray;
+    string emitVerilog() override { V3ERROR_NA_RETURN(""); }
+    string emitC() override { V3ERROR_NA_RETURN(""); }
+    bool cleanOut() const override { return true; }
+};
 class AstDot final : public AstNodeExpr {
    // A dot separating paths in an AstVarXRef, AstFuncRef or AstTaskRef
    // These are eliminated in the link stage
@@ -1048,7 +1076,7 @@ public:
 };
 class AstEnumItemRef final : public AstNodeExpr {
    AstEnumItem* m_itemp;  // [AfterLink] Pointer to item
-    AstNodeModule* m_classOrPackagep;  // Package hierarchy
+    AstNodeModule* m_classOrPackagep;  // Class/package in which it was defined
 public:
    AstEnumItemRef(FileLine* fl, AstEnumItem* itemp, AstNodeModule* classOrPackagep)
        : ASTGEN_SUPER_EnumItemRef(fl)
@@ -1058,7 +1086,7 @@ public:
    }
    ASTGEN_MEMBERS_AstEnumItemRef;
    void dump(std::ostream& str) const override;
-    string name() const override { return itemp()->name(); }
+    string name() const override VL_MT_STABLE { return itemp()->name(); }
    int instrCount() const override { return 0; }
    const char* broken() const override;
    void cloneRelink() override {
@@ -1068,7 +1096,7 @@ public:
        const AstEnumItemRef* const sp = static_cast<const AstEnumItemRef*>(samep);
        return itemp() == sp->itemp();
    }
-    AstEnumItem* itemp() const { return m_itemp; }
+    AstEnumItem* itemp() const VL_MT_STABLE { return m_itemp; }
    string emitVerilog() override { V3ERROR_NA_RETURN(""); }
    string emitC() override { V3ERROR_NA_RETURN(""); }
    bool cleanOut() const override { return true; }
@@ -1092,7 +1120,8 @@ public:
    // METHODS
    string emitVerilog() override { V3ERROR_NA_RETURN(""); }
    string emitC() override { V3ERROR_NA_RETURN(""); }
-    bool cleanOut() const override { return false; }
+    bool cleanOut() const override { return true; }
+    bool isPure() const override { return false; }
    bool same(const AstNode*) const override { return true; }
 };
 class AstFError final : public AstNodeExpr {
@@ -1109,9 +1138,50 @@ public:
    string emitC() override { V3ERROR_NA_RETURN(""); }
    bool cleanOut() const override { return true; }
    int instrCount() const override { return widthInstrs() * 64; }
+    bool isPredictOptimizable() const override { return false; }
    bool isPure() const override { return false; }  // SPECIAL: $display has 'visual' ordering
    bool same(const AstNode* /*samep*/) const override { return true; }
 };
+class AstFOpen final : public AstNodeExpr {
+    // @astgen op2 := filenamep : AstNodeExpr
+    // @astgen op3 := modep : AstNodeExpr
+public:
+    AstFOpen(FileLine* fl, AstNodeExpr* filenamep, AstNodeExpr* modep)
+        : ASTGEN_SUPER_FOpen(fl) {
+        this->filenamep(filenamep);
+        this->modep(modep);
+    }
+    ASTGEN_MEMBERS_AstFOpen;
+    string emitVerilog() override { V3ERROR_NA_RETURN(""); }
+    string emitC() override { V3ERROR_NA_RETURN(""); }
+    bool cleanOut() const override { return true; }
+    string verilogKwd() const override { return "$fopen"; }
+    bool isGateOptimizable() const override { return false; }
+    bool isPredictOptimizable() const override { return false; }
+    bool isPure() const override { return false; }
+    bool isOutputter() const override { return true; }
+    bool isUnlikely() const override { return true; }
+    bool same(const AstNode* /*samep*/) const override { return true; }
+};
+class AstFOpenMcd final : public AstNodeExpr {
+    // @astgen op2 := filenamep : AstNodeExpr
+public:
+    AstFOpenMcd(FileLine* fl, AstNodeExpr* filenamep)
+        : ASTGEN_SUPER_FOpenMcd(fl) {
+        this->filenamep(filenamep);
+    }
+    ASTGEN_MEMBERS_AstFOpenMcd;
+    string emitVerilog() override { V3ERROR_NA_RETURN(""); }
+    string emitC() override { V3ERROR_NA_RETURN(""); }
+    bool cleanOut() const override { return true; }
+    string verilogKwd() const override { return "$fopen"; }
+    bool isGateOptimizable() const override { return false; }
+    bool isPredictOptimizable() const override { return false; }
+    bool isPure() const override { return false; }
+    bool isOutputter() const override { return true; }
+    bool isUnlikely() const override { return true; }
+    bool same(const AstNode* /*samep*/) const override { return true; }
+};
 class AstFRead final : public AstNodeExpr {
    // @astgen op1 := memp : AstNode // VarRef for result
    // @astgen op2 := filep : AstNode // file (must be a VarRef)
@@ -1168,7 +1238,7 @@ public:
        this->filep(filep);
    }
    ASTGEN_MEMBERS_AstFScanF;
-    string name() const override { return m_text; }
+    string name() const override VL_MT_STABLE { return m_text; }
    string verilogKwd() const override { return "$fscanf"; }
    string emitVerilog() override { V3ERROR_NA_RETURN(""); }
    string emitC() override { V3ERROR_NA_RETURN(""); }
@@ -1258,7 +1328,9 @@ public:
    bool cleanOut() const override { return true; }
 };
 class AstImplication final : public AstNodeExpr {
-    // Verilog |-> |=>
+    // Verilog Implication Operator
+    // Nonoverlapping "|=>"
+    // Overlapping "|->" (doesn't currently use this - might make new Ast type)
    // @astgen op1 := lhsp : AstNodeExpr
    // @astgen op2 := rhsp : AstNodeExpr
    // @astgen op3 := sentreep : Optional[AstSenTree]
@@ -1365,7 +1437,7 @@ public:
    string emitC() override { V3ERROR_NA_RETURN(""); }
    bool cleanOut() const override { return true; }
    int instrCount() const override { return widthInstrs(); }
-    string name() const override { return m_name; }  // * = Var name
+    string name() const override VL_MT_STABLE { return m_name; }  // * = Var name
    void name(const string& name) override { m_name = name; }
    bool index() const { return m_index; }
 };
@@ -1373,6 +1445,7 @@ class AstMemberSel final : public AstNodeExpr {
    // @astgen op1 := fromp : AstNodeExpr
    // Don't need the class we are extracting from, as the "fromp()"'s datatype can get us to it
    string m_name;
+    VAccess m_access;  // Read or write, as in AstNodeVarRef
    AstVar* m_varp = nullptr;  // Post link, variable within class that is target of selection
 public:
    AstMemberSel(FileLine* fl, AstNodeExpr* fromp, VFlagChildDType, const string& name)
@@ -1391,12 +1464,14 @@ public:
    void cloneRelink() override;
    const char* broken() const override;
    void dump(std::ostream& str) const override;
-    string name() const override { return m_name; }
+    string name() const override VL_MT_STABLE { return m_name; }
    void name(const string& name) override { m_name = name; }
+    VAccess access() const { return m_access; }
+    void access(const VAccess& flag) { m_access = flag; }
    string emitVerilog() override { V3ERROR_NA_RETURN(""); }
    string emitC() override { V3ERROR_NA_RETURN(""); }
-    bool cleanOut() const override { return false; }
-    bool same(const AstNode* samep) const override { return true; }  // dtype comparison does it
+    bool cleanOut() const override { return true; }
+    bool same(const AstNode* samep) const override;
    int instrCount() const override { return widthInstrs(); }
    AstVar* varp() const { return m_varp; }
    void varp(AstVar* nodep) { m_varp = nodep; }
@@ -1456,7 +1531,7 @@ public:
    }
    ASTGEN_MEMBERS_AstParseRef;
    void dump(std::ostream& str) const override;
-    string name() const override { return m_name; }  // * = Var name
+    string name() const override VL_MT_STABLE { return m_name; }  // * = Var name
    bool same(const AstNode* samep) const override {
        const AstParseRef* const asamep = static_cast<const AstParseRef*>(samep);
        return (expect() == asamep->expect() && m_name == asamep->m_name);
@@ -1533,7 +1608,7 @@ public:
    bool cleanOut() const override { V3ERROR_NA_RETURN(""); }
    int instrCount() const override { return widthInstrs(); }
    AstNodeDType* getChildDTypep() const override { return childDTypep(); }
-    AstNodeDType* subDTypep() const { return dtypep() ? dtypep() : childDTypep(); }
+    AstNodeDType* subDTypep() const VL_MT_STABLE { return dtypep() ? dtypep() : childDTypep(); }
 };
 class AstRand final : public AstNodeExpr {
    // $random/$random(seed) or $urandom/$urandom(seed)
@@ -1579,6 +1654,26 @@ public:
    bool reset() const { return m_reset; }
    bool urandom() const { return m_urandom; }
 };
+class AstRandRNG final : public AstNodeExpr {
+    // Random used in a class using VlRNG
+    // Return a random number, based upon width()
+public:
+    AstRandRNG(FileLine* fl, AstNodeDType* dtp)
+        : ASTGEN_SUPER_RandRNG(fl) {
+        dtypep(dtp);
+    }
+    ASTGEN_MEMBERS_AstRandRNG;
+    string emitVerilog() override { return "%f$rngrandom()"; }
+    string emitC() override {
+        return isWide() ? "VL_RANDOM_RNG_%nq(__Vm_rng, %nw, %P)"  //
+                        : "VL_RANDOM_RNG_%nq(__Vm_rng)";
+    }
+    bool cleanOut() const override { return false; }
+    bool isGateOptimizable() const override { return false; }
+    bool isPredictOptimizable() const override { return false; }
+    int instrCount() const override { return INSTR_COUNT_PLI; }
+    bool same(const AstNode* /*samep*/) const override { return true; }
+};
 class AstRose final : public AstNodeExpr {
    // Verilog $rose
    // @astgen op1 := exprp : AstNodeExpr
@@ -1630,7 +1725,7 @@ public:
        addExprsp(exprsp);
    }
    ASTGEN_MEMBERS_AstSFormatF;
-    string name() const override { return m_text; }
+    string name() const override VL_MT_STABLE { return m_text; }
    int instrCount() const override { return INSTR_COUNT_PLI; }
    bool same(const AstNode* samep) const override {
        return text() == static_cast<const AstSFormatF*>(samep)->text();
@@ -1665,7 +1760,7 @@ public:
        this->fromp(fromp);
    }
    ASTGEN_MEMBERS_AstSScanF;
-    string name() const override { return m_text; }
+    string name() const override VL_MT_STABLE { return m_text; }
    string verilogKwd() const override { return "$sscanf"; }
    string emitVerilog() override { V3ERROR_NA_RETURN(""); }
    string emitC() override { V3ERROR_NA_RETURN(""); }
@@ -1836,7 +1931,7 @@ public:
    bool same(const AstNode* /*samep*/) const override { return true; }
 };
 class AstStructSel final : public AstNodeExpr {
-    // Unpacked struct member access
+    // Unpacked struct/union member access
    // Parents: math|stmt
    // Children: varref, math
    // @astgen op1 := fromp : AstNodeExpr
@@ -1850,11 +1945,14 @@ public:
        dtypep(nullptr);  // V3Width will resolve
    }
    ASTGEN_MEMBERS_AstStructSel;
-    string name() const override { return m_name; }
+    string name() const override VL_MT_STABLE { return m_name; }
    void name(const string& name) override { m_name = name; }
    string emitVerilog() override { V3ERROR_NA_RETURN(""); }
    string emitC() override { V3ERROR_NA_RETURN(""); }
-    bool cleanOut() const override { return false; }
+    bool cleanOut() const override {
+        // Not a union
+        return VN_IS(fromp()->dtypep()->skipRefp(), StructDType);
+    }
    bool same(const AstNode* samep) const override {
        const AstStructSel* const sp = static_cast<const AstStructSel*>(samep);
        return m_name == sp->m_name;
@@ -1931,7 +2029,7 @@ public:
    bool same(const AstNode* /*samep*/) const override { return true; }
    bool cleanOut() const override { return true; }
    AstNodeDType* getChildDTypep() const override { return childDTypep(); }
-    AstNodeDType* subDTypep() const { return dtypep() ? dtypep() : childDTypep(); }
+    AstNodeDType* subDTypep() const VL_MT_STABLE { return dtypep() ? dtypep() : childDTypep(); }
 };
 class AstTimePrecision final : public AstNodeExpr {
    // Verilog $timeprecision
@@ -2047,14 +2145,14 @@ class AstWith final : public AstNodeExpr {
    // Children: expression (equation establishing the with)
    // @astgen op1 := indexArgRefp : AstLambdaArgRef
    // @astgen op2 := valueArgRefp : AstLambdaArgRef
-    // @astgen op3 := exprp : AstNodeExpr
+    // @astgen op3 := exprp : List[AstNode]
 public:
    AstWith(FileLine* fl, AstLambdaArgRef* indexArgRefp, AstLambdaArgRef* valueArgRefp,
            AstNodeExpr* exprp)
        : ASTGEN_SUPER_With(fl) {
        this->indexArgRefp(indexArgRefp);
        this->valueArgRefp(valueArgRefp);
-        this->exprp(exprp);
+        this->addExprp(exprp);
    }
    ASTGEN_MEMBERS_AstWith;
    bool same(const AstNode* /*samep*/) const override { return true; }
@@ -2159,7 +2257,7 @@ public:
    void numberOperate(V3Number& out, const V3Number& lhs, const V3Number& rhs) override {
        out.opCompareNN(lhs, rhs, m_ignoreCase);
    }
-    string name() const override { return m_ignoreCase ? "icompare" : "compare"; }
+    string name() const override VL_MT_STABLE { return m_ignoreCase ? "icompare" : "compare"; }
    string emitVerilog() override {
        return m_ignoreCase ? "%k(%l.icompare(%r))" : "%k(%l.compare(%r))";
    }
@@ -2364,6 +2462,7 @@ public:
    bool sizeMattersLhs() const override { return false; }
    bool sizeMattersRhs() const override { return false; }
    int instrCount() const override { return widthInstrs() * 64; }
+    bool isPredictOptimizable() const override { return false; }
    bool isPure() const override { return false; }  // SPECIAL: $display has 'visual' ordering
    AstNode* filep() const { return lhsp(); }
    AstNode* charp() const { return rhsp(); }
@@ -2382,7 +2481,7 @@ public:
    void numberOperate(V3Number& out, const V3Number& lhs, const V3Number& rhs) override {
        out.opGetcN(lhs, rhs);
    }
-    string name() const override { return "getc"; }
+    string name() const override VL_MT_STABLE { return "getc"; }
    string emitVerilog() override { return "%k(%l.getc(%r))"; }
    string emitC() override { return "VL_GETC_N(%li,%ri)"; }
    string emitSimpleOperator() override { return ""; }
@@ -3946,16 +4045,19 @@ public:
 // === AstNodeCCall ===
 class AstCCall final : public AstNodeCCall {
    // C++ function call
-    string m_selfPointer;  // Output code object pointer (e.g.: 'this')
-
+    VSelfPointerText m_selfPointer
+        = VSelfPointerText{VSelfPointerText::Empty()};  // Output code object
+                                                        // pointer (e.g.: 'this')
 public:
    AstCCall(FileLine* fl, AstCFunc* funcp, AstNodeExpr* argsp = nullptr)
        : ASTGEN_SUPER_CCall(fl, funcp, argsp) {}
    ASTGEN_MEMBERS_AstCCall;

-    string selfPointer() const { return m_selfPointer; }
-    void selfPointer(const string& value) { m_selfPointer = value; }
-    string selfPointerProtect(bool useSelfForThis) const;
+    const VSelfPointerText& selfPointer() const { return m_selfPointer; }
+    void selfPointer(const VSelfPointerText& selfPointer) { m_selfPointer = selfPointer; }
+    string selfPointerProtect(bool useSelfForThis) const {
+        return selfPointer().protect(useSelfForThis, protect());
+    }
 };
 class AstCMethodCall final : public AstNodeCCall {
    // C++ method call
@@ -4012,7 +4114,6 @@ public:
        BROKEN_RTN(!fromp());
        return nullptr;
    }
-    void dump(std::ostream& str) const override;
 };
 class AstNew final : public AstNodeFTaskRef {
    // New as constructor
@@ -4263,7 +4364,7 @@ public:
                       const V3Number& ths) override {
        out.opPutcN(lhs, rhs, ths);
    }
-    string name() const override { return "putc"; }
+    string name() const override VL_MT_STABLE { return "putc"; }
    string emitVerilog() override { return "%k(%l.putc(%r,%t))"; }
    string emitC() override { return "VL_PUTC_N(%li,%ri,%ti)"; }
    string emitSimpleOperator() override { return ""; }
@@ -4370,7 +4471,7 @@ public:
                       const V3Number& ths) override {
        out.opSubstrN(lhs, rhs, ths);
    }
-    string name() const override { return "substr"; }
+    string name() const override VL_MT_STABLE { return "substr"; }
    string emitVerilog() override { return "%k(%l.substr(%r,%t))"; }
    string emitC() override { return "VL_SUBSTR_N(%li,%ri,%ti)"; }
    string emitSimpleOperator() override { return ""; }
@@ -4447,7 +4548,7 @@ public:
    }
    ASTGEN_MEMBERS_AstAtoN;
    void numberOperate(V3Number& out, const V3Number& lhs) override { out.opAtoN(lhs, m_fmt); }
-    string name() const override {
+    string name() const override VL_MT_STABLE {
        switch (m_fmt) {
        case ATOI: return "atoi";
        case ATOHEX: return "atohex";
@@ -4596,7 +4697,7 @@ public:
    ASTGEN_MEMBERS_AstCvtPackString;
    void numberOperate(V3Number& out, const V3Number& lhs) override { out.opAssign(lhs); }
    string emitVerilog() override { return "%f$_CAST(%l)"; }
-    string emitC() override { return "VL_CVT_PACK_STR_N%lq(%lW, %li)"; }
+    string emitC() override { V3ERROR_NA_RETURN(""); }
    bool cleanOut() const override { return true; }
    bool cleanLhs() const override { return true; }
    bool sizeMattersLhs() const override { return false; }
@@ -5274,15 +5375,15 @@ public:
 class AstVarRef final : public AstNodeVarRef {
    // A reference to a variable (lvalue or rvalue)
 public:
-    AstVarRef(FileLine* fl, const string& name, const VAccess& access)
-        : ASTGEN_SUPER_VarRef(fl, name, nullptr, access) {}
    // This form only allowed post-link because output/wire compression may
    // lead to deletion of AstVar's
    inline AstVarRef(FileLine* fl, AstVar* varp, const VAccess& access);
    // This form only allowed post-link (see above)
    inline AstVarRef(FileLine* fl, AstVarScope* varscp, const VAccess& access);
    ASTGEN_MEMBERS_AstVarRef;
+    inline string name() const override;  // * = Var name
    void dump(std::ostream& str) const override;
+    const char* broken() const override;
    bool same(const AstNode* samep) const override;
    inline bool same(const AstVarRef* samep) const;
    inline bool sameNoLvalue(AstVarRef* samep) const;
@@ -5294,14 +5395,17 @@ public:
 class AstVarXRef final : public AstNodeVarRef {
    // A VarRef to something in another module before AstScope.
    // Includes pin on a cell, as part of a ASSIGN statement to connect I/Os until AstScope
+    string m_name;
    string m_dotted;  // Dotted part of scope the name()'ed reference is under or ""
    string m_inlinedDots;  // Dotted hierarchy flattened out
 public:
    AstVarXRef(FileLine* fl, const string& name, const string& dotted, const VAccess& access)
-        : ASTGEN_SUPER_VarXRef(fl, name, nullptr, access)
+        : ASTGEN_SUPER_VarXRef(fl, nullptr, access)
+        , m_name{name}
        , m_dotted{dotted} {}
    inline AstVarXRef(FileLine* fl, AstVar* varp, const string& dotted, const VAccess& access);
    ASTGEN_MEMBERS_AstVarXRef;
+    string name() const override VL_MT_STABLE { return m_name; }  // * = Var name
    void dump(std::ostream& str) const override;
    string dotted() const { return m_dotted; }
    void dotted(const string& dotted) { m_dotted = dotted; }
@@ -32,7 +32,7 @@

 class AstNodeBlock VL_NOT_FINAL : public AstNode {
    // A Begin/fork block
-    // @astgen op1 := stmtsp : List[AstNode]
+    // @astgen op2 := stmtsp : List[AstNode]
    // Parents: statement
 private:
    string m_name;  // Name of block
@@ -48,7 +48,7 @@ protected:
 public:
    ASTGEN_MEMBERS_AstNodeBlock;
    void dump(std::ostream& str) const override;
-    string name() const override { return m_name; }  // * = Block name
+    string name() const override VL_MT_STABLE { return m_name; }  // * = Block name
    void name(const string& name) override { m_name = name; }
    bool unnamed() const { return m_unnamed; }
    bool isFirstInMyListOfStatements(AstNode* nodep) const override { return nodep == stmtsp(); }
@@ -81,11 +81,12 @@ private:
    bool m_isConstructor : 1;  // Class constructor
    bool m_isHideLocal : 1;  // Verilog local
    bool m_isHideProtected : 1;  // Verilog protected
-    bool m_pure : 1;  // DPI import pure (vs. virtual pure)
+    bool m_dpiPure : 1;  // DPI import pure (vs. virtual pure)
    bool m_pureVirtual : 1;  // Pure virtual
    bool m_recursive : 1;  // Recursive or part of recursion
    bool m_underGenerate : 1;  // Under generate (for warning)
    bool m_virtual : 1;  // Virtual method in class
+    bool m_needProcess : 1;  // Implements part of a process that allocates std::process
    VLifetime m_lifetime;  // Lifetime
 protected:
    AstNodeFTask(VNType t, FileLine* fl, const string& name, AstNode* stmtsp)
@@ -106,21 +107,25 @@ protected:
        , m_isConstructor{false}
        , m_isHideLocal{false}
        , m_isHideProtected{false}
-        , m_pure{false}
+        , m_dpiPure{false}
        , m_pureVirtual{false}
        , m_recursive{false}
        , m_underGenerate{false}
-        , m_virtual{false} {
+        , m_virtual{false}
+        , m_needProcess{false} {
        addStmtsp(stmtsp);
        cname(name);  // Might be overridden by dpi import/export
    }

 public:
    ASTGEN_MEMBERS_AstNodeFTask;
+    virtual AstNodeFTask* cloneType(const string& name) = 0;
    void dump(std::ostream& str = std::cout) const override;
-    string name() const override { return m_name; }  // * = Var name
+    string name() const override VL_MT_STABLE { return m_name; }  // * = Var name
    bool maybePointedTo() const override { return true; }
-    bool isGateOptimizable() const override { return !((m_dpiExport || m_dpiImport) && !m_pure); }
+    bool isGateOptimizable() const override {
+        return !((m_dpiExport || m_dpiImport) && !m_dpiPure);
+    }
    // {AstFunc only} op1 = Range output variable
    void name(const string& name) override { m_name = name; }
    string cname() const { return m_cname; }
@@ -160,8 +165,8 @@ public:
    void isHideLocal(bool flag) { m_isHideLocal = flag; }
    bool isHideProtected() const { return m_isHideProtected; }
    void isHideProtected(bool flag) { m_isHideProtected = flag; }
-    void pure(bool flag) { m_pure = flag; }
-    bool pure() const { return m_pure; }
+    void dpiPure(bool flag) { m_dpiPure = flag; }
+    bool dpiPure() const { return m_dpiPure; }
    void pureVirtual(bool flag) { m_pureVirtual = flag; }
    bool pureVirtual() const { return m_pureVirtual; }
    void recursive(bool flag) { m_recursive = flag; }
@@ -170,9 +175,20 @@ public:
    bool underGenerate() const { return m_underGenerate; }
    void isVirtual(bool flag) { m_virtual = flag; }
    bool isVirtual() const { return m_virtual; }
+    void setNeedProcess() { m_needProcess = true; }
+    bool needProcess() const { return m_needProcess; }
    void lifetime(const VLifetime& flag) { m_lifetime = flag; }
    VLifetime lifetime() const { return m_lifetime; }
    bool isFirstInMyListOfStatements(AstNode* n) const override { return n == stmtsp(); }
+    void propagateAttrFrom(const AstNodeFTask* fromp) {
+        // Creating a wrapper with e.g. cloneType(); preserve some attributes
+        classMethod(fromp->classMethod());
+        isHideLocal(fromp->isHideLocal());
+        isHideProtected(fromp->isHideProtected());
+        isVirtual(fromp->isVirtual());
+        lifetime(fromp->lifetime());
+        underGenerate(fromp->underGenerate());
+    }
 };
 class AstNodeFile VL_NOT_FINAL : public AstNode {
    // Emitted Output file
@@ -186,7 +202,7 @@ public:
        , m_name{name} {}
    ASTGEN_MEMBERS_AstNodeFile;
    void dump(std::ostream& str) const override;
-    string name() const override { return m_name; }
+    string name() const override VL_MT_STABLE { return m_name; }
    bool same(const AstNode* /*samep*/) const override { return true; }
 };
 class AstNodeModule VL_NOT_FINAL : public AstNode {
@@ -234,7 +250,7 @@ public:
    ASTGEN_MEMBERS_AstNodeModule;
    void dump(std::ostream& str) const override;
    bool maybePointedTo() const override { return true; }
-    string name() const override { return m_name; }
+    string name() const override VL_MT_STABLE { return m_name; }
    virtual bool timescaleMatters() const = 0;
    // ACCESSORS
    void name(const string& name) override { m_name = name; }
@@ -272,10 +288,13 @@ public:
 class AstNodeProcedure VL_NOT_FINAL : public AstNode {
    // IEEE procedure: initial, final, always
    // @astgen op2 := stmtsp : List[AstNode] // Note: op1 is used in some sub-types only
-    bool m_suspendable = false;  // Is suspendable by a Delay, EventControl, etc.
+    bool m_suspendable : 1;  // Is suspendable by a Delay, EventControl, etc.
+    bool m_needProcess : 1;  // Implements part of a process that allocates std::process
 protected:
    AstNodeProcedure(VNType t, FileLine* fl, AstNode* stmtsp)
        : AstNode{t, fl} {
+        m_needProcess = false;
+        m_suspendable = false;
        addStmtsp(stmtsp);
    }

@@ -286,6 +305,8 @@ public:
    bool isJustOneBodyStmt() const { return stmtsp() && !stmtsp()->nextp(); }
    bool isSuspendable() const { return m_suspendable; }
    void setSuspendable() { m_suspendable = true; }
+    bool needProcess() const { return m_needProcess; }
+    void setNeedProcess() { m_needProcess = true; }
 };
 class AstNodeRange VL_NOT_FINAL : public AstNode {
    // A range, sized or unsized
@@ -308,8 +329,6 @@ public:
    // METHODS
    void addNextStmt(AstNode* newp,
                     AstNode* belowp) override;  // Stop statement searchback here
-    void addBeforeStmt(AstNode* newp,
-                       AstNode* belowp) override;  // Stop statement searchback here
    void dump(std::ostream& str = std::cout) const override;
 };
 class AstNodeAssign VL_NOT_FINAL : public AstNodeStmt {
@@ -373,7 +392,7 @@ public:
        this->addPasssp(passsp);
    }
    ASTGEN_MEMBERS_AstNodeCoverOrAssert;
-    string name() const override { return m_name; }  // * = Var name
+    string name() const override VL_MT_STABLE { return m_name; }  // * = Var name
    bool same(const AstNode* samep) const override { return samep->name() == name(); }
    void name(const string& name) override { m_name = name; }
    void dump(std::ostream& str = std::cout) const override;
@@ -512,7 +531,7 @@ public:
    }
    ASTGEN_MEMBERS_AstActive;
    void dump(std::ostream& str = std::cout) const override;
-    string name() const override { return m_name; }
+    string name() const override VL_MT_STABLE { return m_name; }
    const char* broken() const override;
    void cloneRelink() override;
    // Statements are broken into pieces, as some must come before others.
@@ -537,7 +556,7 @@ public:
    }
    ASTGEN_MEMBERS_AstBind;
    // ACCESSORS
-    string name() const override { return m_name; }  // * = Bind Target name
+    string name() const override VL_MT_STABLE { return m_name; }  // * = Bind Target name
    void name(const string& name) override { m_name = name; }
 };
 class AstCFunc final : public AstNode {
@@ -571,13 +590,14 @@ private:
    bool m_isInline : 1;  // Inline function
    bool m_isVirtual : 1;  // Virtual function
    bool m_entryPoint : 1;  // User may call into this top level function
-    bool m_pure : 1;  // Pure function
+    bool m_dpiPure : 1;  // Pure DPI function
    bool m_dpiContext : 1;  // Declared as 'context' DPI import/export function
    bool m_dpiExportDispatcher : 1;  // This is the DPI export entry point (i.e.: called by user)
    bool m_dpiExportImpl : 1;  // DPI export implementation (called from DPI dispatcher via lookup)
    bool m_dpiImportPrototype : 1;  // This is the DPI import prototype (i.e.: provided by user)
    bool m_dpiImportWrapper : 1;  // Wrapper for invoking DPI import prototype from generated code
    bool m_dpiTraceInit : 1;  // DPI trace_init
+    bool m_needProcess : 1;  // Implements part of a process that allocates std::process
 public:
    AstCFunc(FileLine* fl, const string& name, AstScope* scopep, const string& rtnType = "")
        : ASTGEN_SUPER_CFunc(fl) {
@@ -597,8 +617,9 @@ public:
        m_isLoose = false;
        m_isInline = false;
        m_isVirtual = false;
+        m_needProcess = false;
        m_entryPoint = false;
-        m_pure = false;
+        m_dpiPure = false;
        m_dpiContext = false;
        m_dpiExportDispatcher = false;
        m_dpiExportImpl = false;
@@ -607,7 +628,7 @@ public:
        m_dpiTraceInit = false;
    }
    ASTGEN_MEMBERS_AstCFunc;
-    string name() const override { return m_name; }
+    string name() const override VL_MT_STABLE { return m_name; }
    const char* broken() const override;
    void cloneRelink() override;
    bool maybePointedTo() const override { return true; }
@@ -665,10 +686,12 @@ public:
    void isInline(bool flag) { m_isInline = flag; }
    bool isVirtual() const { return m_isVirtual; }
    void isVirtual(bool flag) { m_isVirtual = flag; }
+    bool needProcess() const { return m_needProcess; }
+    void setNeedProcess() { m_needProcess = true; }
    bool entryPoint() const { return m_entryPoint; }
    void entryPoint(bool flag) { m_entryPoint = flag; }
-    bool pure() const { return m_pure; }
-    void pure(bool flag) { m_pure = flag; }
+    bool dpiPure() const { return m_dpiPure; }
+    void dpiPure(bool flag) { m_dpiPure = flag; }
    bool dpiContext() const { return m_dpiContext; }
    void dpiContext(bool flag) { m_dpiContext = flag; }
    bool dpiExportDispatcher() const VL_MT_SAFE { return m_dpiExportDispatcher; }
@@ -688,6 +711,16 @@ public:
               && finalsp() == nullptr;
    }
 };
+class AstCLocalScope final : public AstNode {
+    // Pack statements into an unnamed scope when generating C++
+    // @astgen op1 := stmtsp : List[AstNode]
+public:
+    AstCLocalScope(FileLine* fl, AstNode* stmtsp)
+        : ASTGEN_SUPER_CLocalScope(fl) {
+        this->addStmtsp(stmtsp);
+    }
+    ASTGEN_MEMBERS_AstCLocalScope;
+};
 class AstCUse final : public AstNode {
    // C++ use of a class or #include; indicates need of forward declaration
    // Parents:  NODEMODULE
@@ -702,7 +735,7 @@ public:
        , m_useType{useType} {}
    ASTGEN_MEMBERS_AstCUse;
    void dump(std::ostream& str = std::cout) const override;
-    string name() const override { return m_name; }
+    string name() const override VL_MT_STABLE { return m_name; }
    VUseType useType() const { return m_useType; }
 };
 class AstCaseItem final : public AstNode {
@@ -755,7 +788,7 @@ public:
    const char* broken() const override;
    bool maybePointedTo() const override { return true; }
    // ACCESSORS
-    string name() const override { return m_name; }  // * = Cell name
+    string name() const override VL_MT_STABLE { return m_name; }  // * = Cell name
    void name(const string& name) override { m_name = name; }
    string origName() const override { return m_origName; }  // * = Original name
    void origName(const string& name) { m_origName = name; }
@@ -794,7 +827,7 @@ public:
    void dump(std::ostream& str) const override;
    const char* broken() const override;
    // ACCESSORS
-    string name() const override { return m_name; }  // * = Cell name
+    string name() const override VL_MT_STABLE { return m_name; }  // * = Cell name
    string origModName() const { return m_origModName; }  // * = modp()->origName() before inlining
    void name(const string& name) override { m_name = name; }
    void scopep(AstScope* scp) { m_scopep = scp; }
@@ -809,6 +842,8 @@ class AstClassExtends final : public AstNode {
    // @astgen op1 := childDTypep : Optional[AstNodeDType]
    // @astgen op2 := classOrPkgsp : Optional[AstNode]
    const bool m_isImplements = false;  // class implements
+    bool m_parameterized = false;  // has parameters in its statement
+
 public:
    AstClassExtends(FileLine* fl, AstNode* classOrPkgsp, bool isImplements)
        : ASTGEN_SUPER_ClassExtends(fl)
@@ -819,8 +854,12 @@ public:
    void dump(std::ostream& str) const override;
    bool hasDType() const override { return true; }
    string verilogKwd() const override { return isImplements() ? "implements" : "extends"; }
-    AstClass* classp() const;  // Class being extended (after link)
+    // Class being extended (after link and instantiation if needed)
+    AstClass* classOrNullp() const;
+    AstClass* classp() const;  // Like above, but throws error if nulll
    bool isImplements() const { return m_isImplements; }
+    void parameterized(bool flag) { m_parameterized = flag; }
+    bool parameterized() const { return m_parameterized; }
 };
 class AstClocking final : public AstNode {
    // Parents:  MODULE
@@ -845,7 +884,7 @@ public:
    }
    ASTGEN_MEMBERS_AstClocking;
    void dump(std::ostream& str) const override;
-    std::string name() const override { return m_name; }
+    std::string name() const override VL_MT_STABLE { return m_name; }
    bool isDefault() const { return m_isDefault; }
    bool isGlobal() const { return m_isGlobal; }
 };
@@ -863,8 +902,8 @@ public:
        : ASTGEN_SUPER_ClockingItem(fl) {
        m_direction = direction;
        this->skewp(skewp);
-        if (AstAssign* const assignp = VN_CAST(clockingDeclp, Assign)) {
-            this->assignp(assignp);
+        if (AstAssign* const clkAssignp = VN_CAST(clockingDeclp, Assign)) {
+            this->assignp(clkAssignp);
        } else {
            exprp(VN_AS(clockingDeclp, NodeExpr));
        }
@@ -916,7 +955,7 @@ public:
        , m_path{path} {
        this->rhsp(rhsp);
    }
-    string name() const override { return m_name; }  // * = Scope name
+    string name() const override VL_MT_STABLE { return m_name; }  // * = Scope name
    ASTGEN_MEMBERS_AstDefParam;
    bool same(const AstNode*) const override { return true; }
    string path() const { return m_path; }
@@ -934,7 +973,7 @@ public:
        , m_name{vname}
        , m_cname{cname} {}
    ASTGEN_MEMBERS_AstDpiExport;
-    string name() const override { return m_name; }
+    string name() const override VL_MT_STABLE { return m_name; }
    void name(const string& name) override { m_name = name; }
    string cname() const { return m_cname; }
    void cname(const string& cname) { m_cname = cname; }
@@ -952,7 +991,7 @@ public:
        BROKEN_RTN(!fmtp());
        return nullptr;
    }
-    string verilogKwd() const override { return (string("$") + string(displayType().ascii())); }
+    string verilogKwd() const override { return string{"$"} + string{displayType().ascii()}; }
    bool isGateOptimizable() const override { return false; }
    bool isPredictOptimizable() const override { return false; }
    bool isPure() const override { return false; }  // SPECIAL: $display has 'visual' ordering
@@ -995,7 +1034,7 @@ public:
        BROKEN_RTN(!m_depGraphp);
        return nullptr;
    }
-    string name() const override { return m_name; }
+    string name() const override VL_MT_STABLE { return m_name; }
    V3Graph* depGraphp() { return m_depGraphp; }
    const V3Graph* depGraphp() const { return m_depGraphp; }
 };
@@ -1033,7 +1072,7 @@ public:
    AstIntfRef(FileLine* fl, const string& name)
        : ASTGEN_SUPER_IntfRef(fl)
        , m_name{name} {}
-    string name() const override { return m_name; }
+    string name() const override VL_MT_STABLE { return m_name; }
    ASTGEN_MEMBERS_AstIntfRef;
 };
 class AstMTaskBody final : public AstNode {
@@ -1070,7 +1109,7 @@ public:
        , m_name{name} {
        this->addVarsp(varsp);
    }
-    string name() const override { return m_name; }
+    string name() const override VL_MT_STABLE { return m_name; }
    bool maybePointedTo() const override { return true; }
    ASTGEN_MEMBERS_AstModport;
 };
@@ -1092,7 +1131,7 @@ public:
    const char* broken() const override;
    void cloneRelink() override;
    void dump(std::ostream& str) const override;
-    string name() const override { return m_name; }
+    string name() const override VL_MT_STABLE { return m_name; }
    bool isImport() const { return !m_export; }
    bool isExport() const { return m_export; }
    AstNodeFTask* ftaskp() const { return m_ftaskp; }  // [After Link] Pointer to variable
@@ -1115,7 +1154,7 @@ public:
    const char* broken() const override;
    void cloneRelink() override;
    void dump(std::ostream& str) const override;
-    string name() const override { return m_name; }
+    string name() const override VL_MT_STABLE { return m_name; }
    void direction(const VDirection& flag) { m_direction = flag; }
    VDirection direction() const { return m_direction; }
    AstVar* varp() const { return m_varp; }  // [After Link] Pointer to variable
@@ -1149,9 +1188,9 @@ public:
    ASTGEN_MEMBERS_AstNetlist;
    const char* broken() const override;
    void cloneRelink() override { V3ERROR_NA; }
-    string name() const override { return "$root"; }
+    string name() const override VL_MT_STABLE { return "$root"; }
    void dump(std::ostream& str) const override;
-    AstNodeModule* topModulep() const {  // Top module in hierarchy
+    AstNodeModule* topModulep() const VL_MT_STABLE {  // Top module in hierarchy
        return modulesp();  // First one in the list, for now
    }
    AstTypeTable* typeTablep() { return m_typeTablep; }
@@ -1198,7 +1237,7 @@ public:
    const char* broken() const override;
    void cloneRelink() override;
    void dump(std::ostream& str) const override;
-    string name() const override { return m_name; }
+    string name() const override VL_MT_STABLE { return m_name; }
    AstPackage* packagep() const { return m_packagep; }
    void packagep(AstPackage* nodep) { m_packagep = nodep; }
 };
@@ -1224,7 +1263,7 @@ public:
    const char* broken() const override;
    void cloneRelink() override;
    void dump(std::ostream& str) const override;
-    string name() const override { return m_name; }
+    string name() const override VL_MT_STABLE { return m_name; }
    AstPackage* packagep() const { return m_packagep; }
    void packagep(AstPackage* nodep) { m_packagep = nodep; }
 };
@@ -1250,7 +1289,7 @@ public:
    ASTGEN_MEMBERS_AstPin;
    void dump(std::ostream& str) const override;
    const char* broken() const override;
-    string name() const override { return m_name; }  // * = Pin name, ""=go by number
+    string name() const override VL_MT_STABLE { return m_name; }  // * = Pin name, ""=go by number
    void name(const string& name) override { m_name = name; }
    string prettyOperatorName() const override;
    bool dotStar() const { return name() == ".*"; }  // Fake name for .* connections until linked
@@ -1278,7 +1317,7 @@ public:
        , m_pinNum{pinnum}
        , m_name{name} {}
    ASTGEN_MEMBERS_AstPort;
-    string name() const override { return m_name; }  // * = Port name
+    string name() const override VL_MT_STABLE { return m_name; }  // * = Port name
    int pinNum() const { return m_pinNum; }  // * = Pin number, for order based instantiation
 };
 class AstPragma final : public AstNode {
@@ -1356,11 +1395,11 @@ public:
    void cloneRelink() override;
    const char* broken() const override;
    bool maybePointedTo() const override { return true; }
-    string name() const override { return m_name; }  // * = Scope name
+    string name() const override VL_MT_STABLE { return m_name; }  // * = Scope name
    void name(const string& name) override { m_name = name; }
    void dump(std::ostream& str) const override;
+    bool same(const AstNode* samep) const override;
    string nameDotless() const;
-    string nameVlSym() const { return ((string("vlSymsp->")) + nameDotless()); }
    AstNodeModule* modp() const { return m_modp; }
    //
    AstScope* aboveScopep() const VL_MT_SAFE { return m_aboveScopep; }
@@ -1495,6 +1534,7 @@ class AstTypeTable final : public AstNode {
    AstEmptyQueueDType* m_emptyQueuep = nullptr;
    AstQueueDType* m_queueIndexp = nullptr;
    AstVoidDType* m_voidp = nullptr;
+    AstStreamDType* m_streamp = nullptr;
    AstBasicDType* m_basicps[VBasicDTypeKwd::_ENUM_MAX]{};
    //
    using DetailedMap = std::map<VBasicTypeKey, AstBasicDType*>;
@@ -1520,6 +1560,7 @@ public:
    AstEmptyQueueDType* findEmptyQueueDType(FileLine* fl);
    AstQueueDType* findQueueIndexDType(FileLine* fl);
    AstVoidDType* findVoidDType(FileLine* fl);
+    AstStreamDType* findStreamDType(FileLine* fl);
    void clearCache();
    void repairCache();
    void dump(std::ostream& str = std::cout) const override;
@@ -1544,9 +1585,11 @@ public:
    ASTGEN_MEMBERS_AstTypedef;
    void dump(std::ostream& str) const override;
    AstNodeDType* getChildDTypep() const override { return childDTypep(); }
-    virtual AstNodeDType* subDTypep() const { return dtypep() ? dtypep() : childDTypep(); }
+    virtual AstNodeDType* subDTypep() const VL_MT_STABLE {
+        return dtypep() ? dtypep() : childDTypep();
+    }
    // METHODS
-    string name() const override { return m_name; }
+    string name() const override VL_MT_STABLE { return m_name; }
    bool maybePointedTo() const override { return true; }
    bool hasDType() const override { return true; }
    void name(const string& flag) override { m_name = flag; }
@@ -1566,7 +1609,7 @@ public:
        , m_name{name} {}
    ASTGEN_MEMBERS_AstTypedefFwd;
    // METHODS
-    string name() const override { return m_name; }
+    string name() const override VL_MT_STABLE { return m_name; }
    bool maybePointedTo() const override { return true; }
 };
 class AstUdpTable final : public AstNode {
@@ -1586,7 +1629,7 @@ public:
        : ASTGEN_SUPER_UdpTableLine(fl)
        , m_text{text} {}
    ASTGEN_MEMBERS_AstUdpTableLine;
-    string name() const override { return m_text; }
+    string name() const override VL_MT_STABLE { return m_text; }
    string text() const { return m_text; }
 };
 class AstVar final : public AstNode {
@@ -1626,6 +1669,7 @@ class AstVar final : public AstNode {
    bool m_usedLoopIdx : 1;  // Variable subject of for unrolling
    bool m_usedVirtIface : 1;  // Signal used through a virtual interface
    bool m_funcLocal : 1;  // Local variable for a function
+    bool m_funcLocalSticky : 1;  // As m_funcLocal but remains set if var is moved to a static
    bool m_funcReturn : 1;  // Return variable for a function
    bool m_attrScBv : 1;  // User force bit vector attribute
    bool m_attrIsolateAssign : 1;  // User isolate_assignments attribute
@@ -1669,6 +1713,7 @@ class AstVar final : public AstNode {
        m_sigUserRdPublic = false;
        m_sigUserRWPublic = false;
        m_funcLocal = false;
+        m_funcLocalSticky = false;
        m_funcReturn = false;
        m_attrScBv = false;
        m_attrIsolateAssign = false;
@@ -1756,7 +1801,8 @@ public:
    }
    ASTGEN_MEMBERS_AstVar;
    void dump(std::ostream& str) const override;
-    string name() const override VL_MT_SAFE { return m_name; }  // * = Var name
+    bool same(const AstNode* samep) const override;
+    string name() const override VL_MT_STABLE VL_MT_SAFE { return m_name; }  // * = Var name
    bool hasDType() const override { return true; }
    bool maybePointedTo() const override { return true; }
    string origName() const override { return m_origName; }  // * = Original name
@@ -1787,17 +1833,17 @@ public:
    string dpiTmpVarType(const string& varName) const;
    // Return Verilator internal type for argument: CData, SData, IData, WData
    string vlArgType(bool named, bool forReturn, bool forFunc, const string& namespc = "",
-                     bool asRef = false) const VL_MT_SAFE;
+                     bool asRef = false) const;
    string vlEnumType() const;  // Return VerilatorVarType: VLVT_UINT32, etc
    string vlEnumDir() const;  // Return VerilatorVarDir: VLVD_INOUT, etc
    string vlPropDecl(const string& propName) const;  // Return VerilatorVarProps declaration
    void combineType(VVarType type);
    AstNodeDType* getChildDTypep() const override { return childDTypep(); }
-    AstNodeDType* dtypeSkipRefp() const VL_MT_SAFE { return subDTypep()->skipRefp(); }
+    AstNodeDType* dtypeSkipRefp() const VL_MT_STABLE { return subDTypep()->skipRefp(); }
    // (Slow) recurse down to find basic data type (Note don't need virtual -
    // AstVar isn't a NodeDType)
-    AstBasicDType* basicp() const VL_MT_SAFE { return subDTypep()->basicp(); }
-    virtual AstNodeDType* subDTypep() const VL_MT_SAFE {
+    AstBasicDType* basicp() const VL_MT_STABLE { return subDTypep()->basicp(); }
+    virtual AstNodeDType* subDTypep() const VL_MT_STABLE {
        return dtypep() ? dtypep() : childDTypep();
    }
    void ansi(bool flag) { m_ansi = flag; }
@@ -1831,7 +1877,10 @@ public:
    void isContinuously(bool flag) { m_isContinuously = flag; }
    void isStatic(bool flag) { m_isStatic = flag; }
    void isIfaceParent(bool flag) { m_isIfaceParent = flag; }
-    void funcLocal(bool flag) { m_funcLocal = flag; }
+    void funcLocal(bool flag) {
+        m_funcLocal = flag;
+        if (flag) m_funcLocalSticky = true;
+    }
    void funcReturn(bool flag) { m_funcReturn = flag; }
    void hasStrengthAssignment(bool flag) { m_hasStrengthAssignment = flag; }
    bool hasStrengthAssignment() { return m_hasStrengthAssignment; }
@@ -1884,9 +1933,7 @@ public:
    bool isClassMember() const { return varType() == VVarType::MEMBER; }
    bool isStatementTemp() const { return (varType() == VVarType::STMTTEMP); }
    bool isXTemp() const { return (varType() == VVarType::XTEMP); }
-    bool isParam() const VL_MT_SAFE {
-        return (varType() == VVarType::LPARAM || varType() == VVarType::GPARAM);
-    }
+    bool isParam() const { return varType().isParam(); }
    bool isGParam() const { return (varType() == VVarType::GPARAM); }
    bool isGenVar() const { return (varType() == VVarType::GENVAR); }
    bool isBitLogic() const {
@@ -1913,6 +1960,7 @@ public:
    bool isStatic() const VL_MT_SAFE { return m_isStatic; }
    bool isLatched() const { return m_isLatched; }
    bool isFuncLocal() const { return m_funcLocal; }
+    bool isFuncLocalSticky() const { return m_funcLocalSticky; }
    bool isFuncReturn() const { return m_funcReturn; }
    bool isPullup() const { return m_isPullup; }
    bool isPulldown() const { return m_isPulldown; }
@@ -1926,18 +1974,25 @@ public:
    string verilogKwd() const override;
    void lifetime(const VLifetime& flag) { m_lifetime = flag; }
    VLifetime lifetime() const { return m_lifetime; }
-    void propagateAttrFrom(AstVar* fromp) {
+    void propagateAttrFrom(const AstVar* fromp) {
        // This is getting connected to fromp; keep attributes
        // Note the method below too
        if (fromp->attrFileDescr()) attrFileDescr(true);
        if (fromp->attrIsolateAssign()) attrIsolateAssign(true);
        if (fromp->isContinuously()) isContinuously(true);
    }
+    void propagateWrapAttrFrom(const AstVar* fromp) {
+        // Creating a function wrapper; keep attributes
+        propagateAttrFrom(fromp);
+        direction(fromp->direction());
+        declDirection(fromp->declDirection());
+        lifetime(fromp->lifetime());
+    }
    bool gateMultiInputOptimizable() const {
        // Ok to gate optimize; must return false if propagateAttrFrom would do anything
        return !isUsedClock();
    }
-    void combineType(AstVar* typevarp) {
+    void combineType(const AstVar* typevarp) {
        // This is same as typevarp (for combining input & reg decls)
        // "this" is the input var. typevarp is the reg var.
        propagateAttrFrom(typevarp);
@@ -1996,11 +2051,12 @@ public:
        return nullptr;
    }
    bool maybePointedTo() const override { return true; }
-    string name() const override { return scopep()->name() + "->" + varp()->name(); }
+    string name() const override VL_MT_STABLE { return scopep()->name() + "->" + varp()->name(); }
    void dump(std::ostream& str) const override;
+    bool same(const AstNode* samep) const override;
    bool hasDType() const override { return true; }
-    AstVar* varp() const { return m_varp; }  // [After Link] Pointer to variable
-    AstScope* scopep() const { return m_scopep; }  // Pointer to scope it's under
+    AstVar* varp() const VL_MT_STABLE { return m_varp; }  // [After Link] Pointer to variable
+    AstScope* scopep() const VL_MT_STABLE { return m_scopep; }  // Pointer to scope it's under
    void scopep(AstScope* nodep) { m_scopep = nodep; }
    bool isTrace() const { return m_trace; }
    void trace(bool flag) { m_trace = flag; }
@@ -2010,7 +2066,7 @@ public:
 class AstBegin final : public AstNodeBlock {
    // A Begin/end named block, only exists shortly after parsing until linking
    // Parents: statement
-    // @astgen op2 := genforp : Optional[AstNode]
+    // @astgen op1 := genforp : Optional[AstNode]

    bool m_generate;  // Underneath a generate
    const bool m_implied;  // Not inserted by user
@@ -2029,6 +2085,7 @@ public:
 };
 class AstFork final : public AstNodeBlock {
    // A fork named block
+    // @astgen op1 := initsp : List[AstNode]
    // Parents: statement
    // Children: statements
 private:
@@ -2054,6 +2111,24 @@ public:
    }
    ASTGEN_MEMBERS_AstFunc;
    bool hasDType() const override { return true; }
+    AstNodeFTask* cloneType(const string& name) override {
+        return new AstFunc{fileline(), name, nullptr, nullptr};
+    }
+};
+class AstLet final : public AstNodeFTask {
+    // Verilog "let" statement
+    // Parents: MODULE
+    // stmtp is always a StmtExpr as Let always returns AstNodeExpr
+public:
+    AstLet(FileLine* fl, const string& name)
+        : ASTGEN_SUPER_Let(fl, name, nullptr) {}
+    ASTGEN_MEMBERS_AstLet;
+    bool hasDType() const override { return true; }
+    const char* broken() const override {
+        BROKEN_RTN(!VN_IS(stmtsp(), StmtExpr));
+        return nullptr;
+    }
+    AstNodeFTask* cloneType(const string& name) override { return new AstLet{fileline(), name}; }
 };
 class AstProperty final : public AstNodeFTask {
    // A property inside a module
@@ -2062,6 +2137,9 @@ public:
        : ASTGEN_SUPER_Property(fl, name, stmtp) {}
    ASTGEN_MEMBERS_AstProperty;
    bool hasDType() const override { return true; }
+    AstNodeFTask* cloneType(const string& name) override {
+        return new AstProperty{fileline(), name, nullptr};
+    }
 };
 class AstTask final : public AstNodeFTask {
    // A task inside a module
@@ -2069,6 +2147,9 @@ public:
    AstTask(FileLine* fl, const string& name, AstNode* stmtp)
        : ASTGEN_SUPER_Task(fl, name, stmtp) {}
    ASTGEN_MEMBERS_AstTask;
+    AstNodeFTask* cloneType(const string& name) override {
+        return new AstTask{fileline(), name, nullptr};
+    }
 };

 // === AstNodeFile ===
@@ -2107,15 +2188,13 @@ public:
 // === AstNodeModule ===
 class AstClass final : public AstNodeModule {
    // @astgen op4 := extendsp : List[AstClassExtends]
-    // TYPES
-    using MemberNameMap = std::map<const std::string, AstNode*>;
    // MEMBERS
-    MemberNameMap m_members;  // Members or method children
-    AstClassPackage* m_classOrPackagep = nullptr;  // Class package this is under
+    AstClassPackage* m_classOrPackagep = nullptr;  // Package it will be emitted with
    bool m_extended = false;  // Is extension or extended by other classes
    bool m_interfaceClass = false;  // Interface class
+    bool m_needRNG = false;  // Need RNG, uses srandom/randomize
    bool m_virtual = false;  // Virtual class
-    void insertCache(AstNode* nodep);
+    bool m_parameterized = false;  // Parameterized class

 public:
    AstClass(FileLine* fl, const string& name)
@@ -2130,25 +2209,23 @@ public:
    AstClassPackage* classOrPackagep() const VL_MT_SAFE { return m_classOrPackagep; }
    void classOrPackagep(AstClassPackage* classpackagep) { m_classOrPackagep = classpackagep; }
    AstNode* membersp() const { return stmtsp(); }
-    void addMembersp(AstNode* nodep) {
-        insertCache(nodep);
-        addStmtsp(nodep);
-    }
-    void clearCache() { m_members.clear(); }
-    void repairCache();
-    AstNode* findMember(const string& name) const {
-        const auto it = m_members.find(name);
-        return (it == m_members.end()) ? nullptr : it->second;
-    }
+    void addMembersp(AstNode* nodep) { addStmtsp(nodep); }
    bool isExtended() const { return m_extended; }
    void isExtended(bool flag) { m_extended = flag; }
    bool isInterfaceClass() const { return m_interfaceClass; }
    void isInterfaceClass(bool flag) { m_interfaceClass = flag; }
    bool isVirtual() const { return m_virtual; }
    void isVirtual(bool flag) { m_virtual = flag; }
+    bool needRNG() const { return m_needRNG; }
+    void needRNG(bool flag) { m_needRNG = flag; }
+    bool isParameterized() const { return m_parameterized; }
+    void isParameterized(bool flag) { m_parameterized = flag; }
    // Return true if this class is an extension of base class (SLOW)
    // Accepts nullptrs
    static bool isClassExtendedFrom(const AstClass* refClassp, const AstClass* baseClassp);
+    // Return the lowest class extended from, or this class
+    AstClass* baseMostClassp();
+    static bool isCacheableChild(const AstNode* nodep);
 };
 class AstClassPackage final : public AstNodeModule {
    // The static information portion of a class (treated similarly to a package)
@@ -2334,20 +2411,20 @@ public:
    inline AstRange(FileLine* fl, int left, int right);
    inline AstRange(FileLine* fl, const VNumRange& range);
    ASTGEN_MEMBERS_AstRange;
-    inline int leftConst() const VL_MT_SAFE;
-    inline int rightConst() const VL_MT_SAFE;
-    int hiConst() const VL_MT_SAFE {
+    inline int leftConst() const VL_MT_STABLE;
+    inline int rightConst() const VL_MT_STABLE;
+    int hiConst() const VL_MT_STABLE {
        const int l = leftConst();
        const int r = rightConst();
        return l > r ? l : r;
    }
-    int loConst() const VL_MT_SAFE {
+    int loConst() const VL_MT_STABLE {
        const int l = leftConst();
        const int r = rightConst();
        return l > r ? r : l;
    }
-    int elementsConst() const VL_MT_SAFE { return hiConst() - loConst() + 1; }
-    bool littleEndian() const { return leftConst() < rightConst(); }
+    int elementsConst() const VL_MT_STABLE { return hiConst() - loConst() + 1; }
+    bool ascending() const { return leftConst() < rightConst(); }
    void dump(std::ostream& str) const override;
    virtual string emitC() { V3ERROR_NA_RETURN(""); }
    bool same(const AstNode* /*samep*/) const override { return true; }
@@ -2450,7 +2527,7 @@ public:
        , m_name{name}
        , m_showAt{showAt} {}
    ASTGEN_MEMBERS_AstComment;
-    string name() const override { return m_name; }  // * = Text
+    string name() const override VL_MT_STABLE { return m_name; }  // * = Text
    bool same(const AstNode* samep) const override { return true; }  // Ignore name in comments
    virtual bool showAt() const { return m_showAt; }
 };
@@ -2591,7 +2668,7 @@ public:
        : ASTGEN_SUPER_Disable(fl)
        , m_name{name} {}
    ASTGEN_MEMBERS_AstDisable;
-    string name() const override { return m_name; }  // * = Block name
+    string name() const override VL_MT_STABLE { return m_name; }  // * = Block name
    void name(const string& flag) override { m_name = flag; }
    bool isBrancher() const override {
        return true;  // SPECIAL: We don't process code after breaks
@@ -2633,8 +2710,8 @@ public:
        return nullptr;
    }
    string verilogKwd() const override {
-        return (filep() ? string("$f") + string(displayType().ascii())
-                        : string("$") + string(displayType().ascii()));
+        return (filep() ? string{"$f"} + string{displayType().ascii()}
+                        : string{"$"} + string{displayType().ascii()});
    }
    bool isGateOptimizable() const override { return false; }
    bool isPredictOptimizable() const override { return false; }
@@ -2651,17 +2728,13 @@ public:
    bool addNewline() const { return displayType().addNewline(); }
 };
 class AstDoWhile final : public AstNodeStmt {
-    // @astgen op1 := precondsp : List[AstNode]
-    // @astgen op2 := condp : AstNodeExpr
-    // @astgen op3 := stmtsp : List[AstNode]
-    // @astgen op4 := incsp : List[AstNode]
+    // @astgen op1 := condp : AstNodeExpr
+    // @astgen op2 := stmtsp : List[AstNode]
 public:
-    AstDoWhile(FileLine* fl, AstNodeExpr* conditionp, AstNode* stmtsp = nullptr,
-               AstNode* incsp = nullptr)
+    AstDoWhile(FileLine* fl, AstNodeExpr* conditionp, AstNode* stmtsp = nullptr)
        : ASTGEN_SUPER_DoWhile(fl) {
        condp(conditionp);
        addStmtsp(stmtsp);
-        addIncsp(incsp);
    }
    ASTGEN_MEMBERS_AstDoWhile;
    bool isGateOptimizable() const override { return false; }
@@ -2739,46 +2812,6 @@ public:
    bool isUnlikely() const override { return true; }
    bool same(const AstNode* /*samep*/) const override { return true; }
 };
-class AstFOpen final : public AstNodeStmt {
-    // Although a system function in IEEE, here a statement which sets the file pointer (MCD)
-    // @astgen op1 := filep : AstNodeExpr
-    // @astgen op2 := filenamep : AstNodeExpr
-    // @astgen op3 := modep : AstNodeExpr
-public:
-    AstFOpen(FileLine* fl, AstNodeExpr* filep, AstNodeExpr* filenamep, AstNodeExpr* modep)
-        : ASTGEN_SUPER_FOpen(fl) {
-        this->filep(filep);
-        this->filenamep(filenamep);
-        this->modep(modep);
-    }
-    ASTGEN_MEMBERS_AstFOpen;
-    string verilogKwd() const override { return "$fopen"; }
-    bool isGateOptimizable() const override { return false; }
-    bool isPredictOptimizable() const override { return false; }
-    bool isPure() const override { return false; }
-    bool isOutputter() const override { return true; }
-    bool isUnlikely() const override { return true; }
-    bool same(const AstNode* /*samep*/) const override { return true; }
-};
-class AstFOpenMcd final : public AstNodeStmt {
-    // Although a system function in IEEE, here a statement which sets the file pointer (MCD)
-    // @astgen op1 := filep : AstNodeExpr
-    // @astgen op2 := filenamep : AstNodeExpr
-public:
-    AstFOpenMcd(FileLine* fl, AstNodeExpr* filep, AstNodeExpr* filenamep)
-        : ASTGEN_SUPER_FOpenMcd(fl) {
-        this->filep(filep);
-        this->filenamep(filenamep);
-    }
-    ASTGEN_MEMBERS_AstFOpenMcd;
-    string verilogKwd() const override { return "$fopen"; }
-    bool isGateOptimizable() const override { return false; }
-    bool isPredictOptimizable() const override { return false; }
-    bool isPure() const override { return false; }
-    bool isOutputter() const override { return true; }
-    bool isUnlikely() const override { return true; }
-    bool same(const AstNode* /*samep*/) const override { return true; }
-};
 class AstFinish final : public AstNodeStmt {
 public:
    explicit AstFinish(FileLine* fl)
@@ -2821,7 +2854,7 @@ public:
    bool isFirstInMyListOfStatements(AstNode* n) const override { return n == stmtsp(); }
 };
 class AstJumpBlock final : public AstNodeStmt {
-    // Block of code including a JumpGo and JumpLabel
+    // Block of code including a single JumpLabel, and 0+ JumpGo's to that label
    // Parents:  {statement list}
    // Children: {statement list, with JumpGo and JumpLabel below}
    // @astgen op1 := stmtsp : List[AstNode]
@@ -2926,7 +2959,7 @@ public:
        : ASTGEN_SUPER_PrintTimeScale(fl) {}
    ASTGEN_MEMBERS_AstPrintTimeScale;
    void name(const string& name) override { m_name = name; }
-    string name() const override { return m_name; }  // * = Var name
+    string name() const override VL_MT_STABLE { return m_name; }  // * = Var name
    void dump(std::ostream& str) const override;
    string verilogKwd() const override { return "$printtimescale"; }
    bool isGateOptimizable() const override { return false; }
@@ -3145,7 +3178,7 @@ public:
    void dump(std::ostream& str) const override;
    int instrCount() const override { return 100; }  // Large...
    ASTGEN_MEMBERS_AstTraceDecl;
-    string name() const override { return m_showname; }
+    string name() const override VL_MT_STABLE { return m_showname; }
    bool maybePointedTo() const override { return true; }
    bool hasDType() const override { return true; }
    bool same(const AstNode* samep) const override { return false; }
@@ -3274,8 +3307,6 @@ public:
    int instrCount() const override { return INSTR_COUNT_BRANCH; }
    bool same(const AstNode* /*samep*/) const override { return true; }
    // Stop statement searchback here
-    void addBeforeStmt(AstNode* newp, AstNode* belowp) override;
-    // Stop statement searchback here
    void addNextStmt(AstNode* newp, AstNode* belowp) override;
    bool isFirstInMyListOfStatements(AstNode* n) const override { return n == stmtsp(); }
 };
@@ -25,6 +25,7 @@
 #include "V3Hasher.h"
 #include "V3PartitionGraph.h"  // Just for mtask dumping
 #include "V3String.h"
+#include "V3Width.h"

 #include "V3Ast__gen_macros.h"  // Generated by 'astgen'

@@ -63,7 +64,7 @@ void AstNodeFTaskRef::cloneRelink() {
 bool AstNodeFTaskRef::isPure() const {
    // TODO: For non-DPI functions we could traverse the AST of function's body to determine
    // pureness.
-    return this->taskp() && this->taskp()->dpiImport() && this->taskp()->pure();
+    return this->taskp() && this->taskp()->dpiImport() && this->taskp()->dpiPure();
 }

 bool AstNodeFTaskRef::isGateOptimizable() const { return m_taskp && m_taskp->isGateOptimizable(); }
@@ -83,12 +84,6 @@ void AstNodeVarRef::cloneRelink() {
    }
 }

-string AstNodeVarRef::selfPointerProtect(bool useSelfForThis) const {
-    const string& sp
-        = useSelfForThis ? VString::replaceWord(selfPointer(), "this", "vlSelf") : selfPointer();
-    return VIdProtect::protectWordsIf(sp, protect());
-}
-
 void AstAddrOfCFunc::cloneRelink() {
    if (m_funcp && m_funcp->clonep()) m_funcp = m_funcp->clonep();
 }
@@ -103,28 +98,8 @@ int AstNodeSel::bitConst() const {
    return (constp ? constp->toSInt() : 0);
 }

-void AstNodeUOrStructDType::repairMemberCache() {
-    clearCache();
-    for (AstMemberDType* itemp = membersp(); itemp; itemp = VN_AS(itemp->nextp(), MemberDType)) {
-        if (m_members.find(itemp->name()) != m_members.end()) {
-            itemp->v3error("Duplicate declaration of member name: " << itemp->prettyNameQ());
-        } else {
-            m_members.emplace(itemp->name(), itemp);
-        }
-    }
-}
-
 const char* AstNodeUOrStructDType::broken() const {
-    std::unordered_set<AstMemberDType*> exists;
-    for (AstMemberDType* itemp = membersp(); itemp; itemp = VN_AS(itemp->nextp(), MemberDType)) {
-        exists.insert(itemp);
-    }
-    for (MemberNameMap::const_iterator it = m_members.begin(); it != m_members.end(); ++it) {
-        if (VL_UNCOVERABLE(exists.find(it->second) == exists.end())) {
-            this->v3error("Internal: Structure member broken: " << it->first);
-            return "member broken";
-        }
-    }
+    BROKEN_RTN(m_classOrPackagep && !m_classOrPackagep->brokeExists());
    return nullptr;
 }

@@ -146,14 +121,22 @@ const char* AstNodeCCall::broken() const {
    BROKEN_RTN(m_funcp && !m_funcp->brokeExists());
    return nullptr;
 }
-bool AstNodeCCall::isPure() const { return funcp()->pure(); }
+bool AstNodeCCall::isPure() const { return funcp()->dpiPure(); }

-string AstCCall::selfPointerProtect(bool useSelfForThis) const {
-    const string& sp
-        = useSelfForThis ? VString::replaceWord(selfPointer(), "this", "vlSelf") : selfPointer();
-    return VIdProtect::protectWordsIf(sp, protect());
+AstNodeCond::AstNodeCond(VNType t, FileLine* fl, AstNodeExpr* condp, AstNodeExpr* thenp,
+                         AstNodeExpr* elsep)
+    : AstNodeTriop{t, fl, condp, thenp, elsep} {
+    UASSERT_OBJ(thenp, this, "No thenp expression");
+    UASSERT_OBJ(elsep, this, "No elsep expression");
+    if (thenp->isClassHandleValue() && elsep->isClassHandleValue()) {
+        // Get the most-deriving class type that both arguments can be casted to.
+        AstNodeDType* const commonClassTypep = V3Width::getCommonClassTypep(thenp, elsep);
+        UASSERT_OBJ(commonClassTypep, this, "No common base class exists");
+        dtypep(commonClassTypep);
+    } else {
+        dtypeFrom(thenp);
+    }
 }
-
 void AstNodeCond::numberOperate(V3Number& out, const V3Number& lhs, const V3Number& rhs,
                                const V3Number& ths) {
    if (lhs.isNeqZero()) {
@@ -232,6 +215,15 @@ int AstBasicDType::widthTotalBytes() const {
    }
 }

+bool AstBasicDType::same(const AstNode* samep) const {
+    const AstBasicDType* const sp = static_cast<const AstBasicDType*>(samep);
+    if (!rangep() && !sp->rangep() && m == sp->m) {
+        return true;
+    } else {
+        return m == sp->m && rangep() && rangep()->sameTree(sp->rangep());
+    }
+}
+
 int AstNodeUOrStructDType::widthTotalBytes() const {
    if (width() <= 8) {
        return 1;
@@ -381,13 +373,15 @@ string AstVar::verilogKwd() const {
        return "wreal";
    } else if (varType() == VVarType::IFACEREF) {
        return "ifaceref";
-    } else {
+    } else if (dtypep()) {
        return dtypep()->name();
+    } else {
+        return "UNKNOWN";
    }
 }

 string AstVar::vlArgType(bool named, bool forReturn, bool forFunc, const string& namespc,
-                         bool asRef) const VL_MT_SAFE {
+                         bool asRef) const {
    UASSERT_OBJ(!forReturn, this,
                "Internal data is never passed as return, but as first argument");
    string ostatic;
@@ -573,7 +567,7 @@ string AstVar::dpiArgType(bool named, bool forReturn) const {
    } else {
        class converter final : public dpiTypesToStringConverter {
            string bitLogicVector(const AstVar* varp, bool isBit) const override {
-                return string(varp->isReadOnly() ? "const " : "")
+                return string{varp->isReadOnly() ? "const " : ""}
                       + dpiTypesToStringConverter::bitLogicVector(varp, isBit) + '*';
            }
            string primitive(const AstVar* varp) const override {
@@ -636,13 +630,13 @@ string AstVar::dpiTmpVarType(const string& varName) const {

 string AstVar::scType() const {
    if (isScBigUint()) {
-        return (string("sc_biguint<") + cvtToStr(widthMin())
+        return (string{"sc_biguint<"} + cvtToStr(widthMin())
                + "> ");  // Keep the space so don't get >>
    } else if (isScUint()) {
-        return (string("sc_uint<") + cvtToStr(widthMin())
+        return (string{"sc_uint<"} + cvtToStr(widthMin())
                + "> ");  // Keep the space so don't get >>
    } else if (isScBv()) {
-        return (string("sc_bv<") + cvtToStr(widthMin()) + "> ");  // Keep the space so don't get >>
+        return (string{"sc_bv<"} + cvtToStr(widthMin()) + "> ");  // Keep the space so don't get >>
    } else if (widthMin() == 1) {
        return "bool";
    } else if (widthMin() <= VL_IDATASIZE) {
@@ -704,7 +698,7 @@ public:
    }
 };

-string AstNodeDType::cType(const string& name, bool /*forFunc*/, bool isRef) const VL_MT_SAFE {
+string AstNodeDType::cType(const string& name, bool /*forFunc*/, bool isRef) const {
    const CTypeRecursed info = cTypeRecurse(false);
    return info.render(name, isRef);
 }
@@ -734,9 +728,9 @@ AstNodeDType::CTypeRecursed AstNodeDType::cTypeRecurse(bool compound) const {
        const CTypeRecursed sub = adtypep->subDTypep()->cTypeRecurse(true);
        info.m_type = "VlSampleQueue<" + sub.m_type + ">";
    } else if (const auto* const adtypep = VN_CAST(dtypep, ClassRefDType)) {
-        info.m_type = "VlClassRef<" + EmitCBaseVisitor::prefixNameProtect(adtypep) + ">";
+        info.m_type = "VlClassRef<" + EmitCBase::prefixNameProtect(adtypep) + ">";
    } else if (const auto* const adtypep = VN_CAST(dtypep, IfaceRefDType)) {
-        info.m_type = EmitCBaseVisitor::prefixNameProtect(adtypep->ifaceViaCellp()) + "*";
+        info.m_type = EmitCBase::prefixNameProtect(adtypep->ifaceViaCellp()) + "*";
    } else if (const auto* const adtypep = VN_CAST(dtypep, UnpackArrayDType)) {
        if (adtypep->isCompound()) compound = true;
        const CTypeRecursed sub = adtypep->subDTypep()->cTypeRecurse(compound);
@@ -745,7 +739,7 @@ AstNodeDType::CTypeRecursed AstNodeDType::cTypeRecurse(bool compound) const {
        info.m_type += ">";
    } else if (VN_IS(dtypep, NodeUOrStructDType) && !VN_AS(dtypep, NodeUOrStructDType)->packed()) {
        const auto* const sdtypep = VN_AS(dtypep, NodeUOrStructDType);
-        info.m_type = EmitCBaseVisitor::prefixNameProtect(sdtypep);
+        info.m_type = EmitCBase::prefixNameProtect(sdtypep);
    } else if (const AstBasicDType* const bdtypep = dtypep->basicp()) {
        // We don't print msb()/lsb() as multidim packed would require recursion,
        // and may confuse users as C++ data is stored always with bit 0 used
@@ -772,6 +766,8 @@ AstNodeDType::CTypeRecursed AstNodeDType::cTypeRecurse(bool compound) const {
            info.m_type = "VlDynamicTriggerScheduler";
        } else if (bdtypep->isForkSync()) {
            info.m_type = "VlForkSync";
+        } else if (bdtypep->isProcessRef()) {
+            info.m_type = "VlProcessRef";
        } else if (bdtypep->isEvent()) {
            info.m_type = "VlEvent";
        } else if (dtypep->widthMin() <= 8) {  // Handle unpacked arrays; not bdtypep->width
@@ -846,7 +842,7 @@ int AstNodeDType::widthPow2() const {
    return 1;
 }

-bool AstNodeDType::isLiteralType() const VL_MT_SAFE {
+bool AstNodeDType::isLiteralType() const VL_MT_STABLE {
    if (const auto* const dtypep = VN_CAST(skipRefp(), BasicDType)) {
        return dtypep->keyword().isLiteralType();
    } else if (const auto* const dtypep = VN_CAST(skipRefp(), UnpackArrayDType)) {
@@ -916,10 +912,10 @@ void AstScope::cloneRelink() {
    }
 }
 string AstScope::nameDotless() const {
-    string out = shortName();
+    string result = shortName();
    string::size_type pos;
-    while ((pos = out.find('.')) != string::npos) out.replace(pos, 1, "__");
-    return out;
+    while ((pos = result.find('.')) != string::npos) result.replace(pos, 1, "__");
+    return result;
 }

 AstVarScope* AstScope::createTemp(const string& name, unsigned width) {
@@ -1057,6 +1053,15 @@ AstVoidDType* AstTypeTable::findVoidDType(FileLine* fl) {
    return m_voidp;
 }

+AstStreamDType* AstTypeTable::findStreamDType(FileLine* fl) {
+    if (VL_UNLIKELY(!m_streamp)) {
+        AstStreamDType* const newp = new AstStreamDType{fl};
+        addTypesp(newp);
+        m_streamp = newp;
+    }
+    return m_streamp;
+}
+
 AstQueueDType* AstTypeTable::findQueueIndexDType(FileLine* fl) {
    if (VL_UNLIKELY(!m_queueIndexp)) {
        AstQueueDType* const newp = new AstQueueDType{fl, AstNode::findUInt32DType(), nullptr};
@@ -1259,44 +1264,17 @@ AstVarScope* AstConstPool::findConst(AstConst* initp, bool mergeDType) {
 //======================================================================
 // Special walking tree inserters

-void AstNode::addBeforeStmt(AstNode* newp, AstNode*) {
-    UASSERT_OBJ(backp(), newp, "Can't find current statement to addBeforeStmt");
-    // Look up; virtual call will find where to put it
-    this->backp()->addBeforeStmt(newp, this);
-}
 void AstNode::addNextStmt(AstNode* newp, AstNode*) {
    UASSERT_OBJ(backp(), newp, "Can't find current statement to addNextStmt");
    // Look up; virtual call will find where to put it
    this->backp()->addNextStmt(newp, this);
 }

-void AstNodeStmt::addBeforeStmt(AstNode* newp, AstNode*) {
-    // Insert newp before current node
-    this->addHereThisAsNext(newp);
-}
 void AstNodeStmt::addNextStmt(AstNode* newp, AstNode*) {
    // Insert newp after current node
    this->addNextHere(newp);
 }

-void AstWhile::addBeforeStmt(AstNode* newp, AstNode* belowp) {
-    // Special, as statements need to be put in different places
-    // Belowp is how we came to recurse up to this point
-    // Preconditions insert first just before themselves (the normal rule
-    // for other statement types)
-    if (belowp == precondsp()) {
-        // Must have been first statement in precondsp list, so newp is new first statement
-        belowp->addHereThisAsNext(newp);
-    } else if (belowp == condp()) {
-        // Goes before condition, IE in preconditions
-        addPrecondsp(newp);
-    } else if (belowp == stmtsp()) {
-        // Was first statement in body, so new front
-        belowp->addHereThisAsNext(newp);
-    } else {
-        belowp->v3fatalSrc("Doesn't look like this was really under the while");
-    }
-}
 void AstWhile::addNextStmt(AstNode* newp, AstNode* belowp) {
    // Special, as statements need to be put in different places
    // Belowp is how we came to recurse up to this point
@@ -1367,6 +1345,7 @@ void AstNode::dump(std::ostream& str) const {
 void AstNodeProcedure::dump(std::ostream& str) const {
    this->AstNode::dump(str);
    if (isSuspendable()) str << " [SUSP]";
+    if (needProcess()) str << " [NPRC]";
 }

 void AstAlways::dump(std::ostream& str) const {
@@ -1430,29 +1409,17 @@ const char* AstClassPackage::broken() const {
 void AstClassPackage::cloneRelink() {
    if (m_classp && m_classp->clonep()) m_classp = m_classp->clonep();
 }
-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, CFunc));
-    if (doit) {
-        if (m_members.find(nodep->name()) != m_members.end()) {
-            nodep->v3error("Duplicate declaration of member name: " << nodep->prettyNameQ());
-        } else {
-            m_members.emplace(nodep->name(), nodep);
-        }
-    }
+bool AstClass::isCacheableChild(const AstNode* nodep) {
+    return (VN_IS(nodep, Var) || VN_IS(nodep, EnumItemRef)
+            || (VN_IS(nodep, NodeFTask) && !VN_AS(nodep, NodeFTask)->isExternProto())
+            || VN_IS(nodep, CFunc));
 }
-void AstClass::repairCache() {
-    clearCache();
-    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);
-        }
+AstClass* AstClass::baseMostClassp() {
+    AstClass* basep = this;
+    while (basep->extendsp() && basep->extendsp()->classp()) {
+        basep = basep->extendsp()->classp();
    }
+    return basep;
 }
 bool AstClass::isClassExtendedFrom(const AstClass* refClassp, const AstClass* baseClassp) {
    // TAIL RECURSIVE
@@ -1482,13 +1449,20 @@ void AstClassExtends::dump(std::ostream& str) const {
    this->AstNode::dump(str);
    if (isImplements()) str << " [IMPLEMENTS]";
 }
-AstClass* AstClassExtends::classp() const {
-    const AstClassRefDType* refp = VN_CAST(dtypep(), ClassRefDType);
-    if (VL_UNLIKELY(!refp)) {  // LinkDot uses this for 'super.'
-        refp = VN_AS(childDTypep(), ClassRefDType);
+AstClass* AstClassExtends::classOrNullp() const {
+    const AstNodeDType* const dtp = dtypep() ? dtypep() : childDTypep();
+    const AstClassRefDType* const refp = VN_CAST(dtp, ClassRefDType);
+    if (refp && !refp->paramsp()) {
+        // Class already resolved
+        return refp->classp();
+    } else {
+        return nullptr;
    }
-    UASSERT_OBJ(refp, this, "class extends non-ref");
-    return refp->classp();
+}
+AstClass* AstClassExtends::classp() const {
+    AstClass* const clsp = classOrNullp();
+    UASSERT_OBJ(clsp, this, "Extended class is unresolved");
+    return clsp;
 }
 void AstClassRefDType::dump(std::ostream& str) const {
    this->AstNodeDType::dump(str);
@@ -1652,10 +1626,25 @@ void AstLogOr::dump(std::ostream& str) const {
    this->AstNodeExpr::dump(str);
    if (sideEffect()) str << " [SIDE]";
 }
+
 void AstMemberDType::dumpSmall(std::ostream& str) const {
    this->AstNodeDType::dumpSmall(str);
    str << "member";
 }
+AstNodeUOrStructDType* AstMemberDType::getChildStructp() const {
+    AstNodeDType* subdtp = skipRefp();
+    while (AstNodeArrayDType* const asubdtp = VN_CAST(subdtp, NodeArrayDType)) {
+        subdtp = asubdtp->subDTypep();
+    }
+    return VN_CAST(subdtp, NodeUOrStructDType);  // Maybe nullptr
+}
+
+bool AstMemberSel::same(const AstNode* samep) const {
+    const AstMemberSel* const sp = static_cast<const AstMemberSel*>(samep);
+    return sp != nullptr && access() == sp->access() && fromp()->same(sp->fromp())
+           && name() == sp->name() && varp()->same(sp->varp());
+}
+
 void AstMemberSel::dump(std::ostream& str) const {
    this->AstNodeExpr::dump(str);
    str << " -> ";
@@ -1672,15 +1661,6 @@ const char* AstMemberSel::broken() const {
    BROKEN_RTN(m_varp && !m_varp->brokeExists());
    return nullptr;
 }
-void AstMethodCall::dump(std::ostream& str) const {
-    this->AstNodeFTaskRef::dump(str);
-    str << " -> ";
-    if (taskp()) {
-        taskp()->dump(str);
-    } else {
-        str << " -> UNLINKED";
-    }
-}
 void AstModportFTaskRef::dump(std::ostream& str) const {
    this->AstNode::dump(str);
    if (isExport()) str << " EXPORT";
@@ -1767,7 +1747,7 @@ void AstTypedef::dump(std::ostream& str) const {
 void AstNodeRange::dump(std::ostream& str) const { this->AstNode::dump(str); }
 void AstRange::dump(std::ostream& str) const {
    this->AstNodeRange::dump(str);
-    if (littleEndian()) str << " [LITTLE]";
+    if (ascending()) str << " [ASCENDING]";
 }
 void AstParamTypeDType::dump(std::ostream& str) const {
    this->AstNodeDType::dump(str);
@@ -1813,7 +1793,7 @@ void AstRefDType::cloneRelink() {
        m_classOrPackagep = m_classOrPackagep->clonep();
    }
 }
-AstNodeDType* AstRefDType::subDTypep() const {
+AstNodeDType* AstRefDType::subDTypep() const VL_MT_STABLE {
    if (typedefp()) return typedefp()->subDTypep();
    return refDTypep();  // Maybe nullptr
 }
@@ -1821,6 +1801,7 @@ void AstNodeUOrStructDType::dump(std::ostream& str) const {
    this->AstNodeDType::dump(str);
    if (packed()) str << " [PACKED]";
    if (isFourstate()) str << " [4STATE]";
+    if (classOrPackagep()) str << " pkg=" << nodeAddr(classOrPackagep());
 }
 void AstNodeDType::dump(std::ostream& str) const {
    this->AstNode::dump(str);
@@ -2052,6 +2033,10 @@ void AstVoidDType::dumpSmall(std::ostream& str) const {
    this->AstNodeDType::dumpSmall(str);
    str << "void";
 }
+void AstStreamDType::dumpSmall(std::ostream& str) const {
+    this->AstNodeDType::dumpSmall(str);
+    str << "stream";
+}
 void AstVarScope::dump(std::ostream& str) const {
    this->AstNode::dump(str);
    if (isTrace()) str << " [T]";
@@ -2063,6 +2048,10 @@ void AstVarScope::dump(std::ostream& str) const {
        str << " ->UNLINKED";
    }
 }
+bool AstVarScope::same(const AstNode* samep) const {
+    const AstVarScope* const asamep = static_cast<const AstVarScope*>(samep);
+    return varp()->same(asamep->varp()) && scopep()->same(asamep->scopep());
+}
 void AstNodeVarRef::dump(std::ostream& str) const {
    this->AstNodeExpr::dump(str);
    if (classOrPackagep()) str << " pkg=" << nodeAddr(classOrPackagep());
@@ -2090,6 +2079,10 @@ void AstVarRef::dump(std::ostream& str) const {
        str << "UNLINKED";
    }
 }
+const char* AstVarRef::broken() const {
+    BROKEN_RTN(!varp());
+    return AstNodeVarRef::broken();
+}
 bool AstVarRef::same(const AstNode* samep) const {
    return same(static_cast<const AstVarRef*>(samep));
 }
@@ -2126,12 +2119,23 @@ void AstVar::dump(std::ostream& str) const {
    if (!lifetime().isNone()) str << " [" << lifetime().ascii() << "] ";
    str << " " << varType();
 }
+bool AstVar::same(const AstNode* samep) const {
+    const AstVar* const asamep = static_cast<const AstVar*>(samep);
+    return name() == asamep->name() && varType() == asamep->varType();
+}
 void AstScope::dump(std::ostream& str) const {
    this->AstNode::dump(str);
    str << " [abovep=" << reinterpret_cast<const void*>(aboveScopep()) << "]";
    str << " [cellp=" << reinterpret_cast<const void*>(aboveCellp()) << "]";
    str << " [modp=" << reinterpret_cast<const void*>(modp()) << "]";
 }
+bool AstScope::same(const AstNode* samep) const {
+    const AstScope* const asamep = static_cast<const AstScope*>(samep);
+    return name() == asamep->name()
+           && ((!aboveScopep() && !asamep->aboveScopep())
+               || (aboveScopep() && asamep->aboveScopep()
+                   && aboveScopep()->name() == asamep->aboveScopep()->name()));
+}
 void AstScopeName::dump(std::ostream& str) const {
    this->AstNodeExpr::dump(str);
    if (dpiExport()) str << " [DPIEX]";
@@ -2283,7 +2287,7 @@ void AstCFile::dump(std::ostream& str) const {
 void AstCFunc::dump(std::ostream& str) const {
    this->AstNode::dump(str);
    if (slow()) str << " [SLOW]";
-    if (pure()) str << " [PURE]";
+    if (dpiPure()) str << " [DPIPURE]";
    if (isStatic()) str << " [STATIC]";
    if (dpiExportDispatcher()) str << " [DPIED]";
    if (dpiExportImpl()) str << " [DPIEI]";
@@ -2294,6 +2298,7 @@ void AstCFunc::dump(std::ostream& str) const {
    if (isDestructor()) str << " [DTOR]";
    if (isVirtual()) str << " [VIRT]";
    if (isCoroutine()) str << " [CORO]";
+    if (needProcess()) str << " [NPRC]";
 }
 const char* AstCAwait::broken() const {
    BROKEN_RTN(m_sensesp && !m_sensesp->brokeExists());
@@ -2312,8 +2317,8 @@ void AstCAwait::dump(std::ostream& str) const {
 int AstCMethodHard::instrCount() const {
    if (AstBasicDType* const basicp = fromp()->dtypep()->basicp()) {
        // TODO: add a more structured description of library methods, rather than using string
-        //       matching. See #3715.
-        if (basicp->isTriggerVec() && m_name == "at") {
+        //       matching. See issue #3715.
+        if (basicp->isTriggerVec() && m_name == "word") {
            // This is an important special case for scheduling so we compute it precisely,
            // it is simply a load.
            return INSTR_COUNT_LD;
@@ -2321,6 +2326,74 @@ int AstCMethodHard::instrCount() const {
    }
    return 0;
 }
+void AstCMethodHard::setPurity() {
+    static const std::map<std::string, bool> isPureMethod{{"andNot", false},
+                                                          {"any", true},
+                                                          {"assign", false},
+                                                          {"at", true},
+                                                          {"atBack", true},
+                                                          {"awaitingCurrentTime", true},
+                                                          {"clear", false},
+                                                          {"clearFired", false},
+                                                          {"commit", false},
+                                                          {"delay", false},
+                                                          {"done", false},
+                                                          {"erase", false},
+                                                          {"evaluate", false},
+                                                          {"evaluation", false},
+                                                          {"exists", true},
+                                                          {"find", true},
+                                                          {"find_first", true},
+                                                          {"find_first_index", true},
+                                                          {"find_index", true},
+                                                          {"find_last", true},
+                                                          {"find_last_index", true},
+                                                          {"fire", false},
+                                                          {"first", false},
+                                                          {"init", false},
+                                                          {"insert", false},
+                                                          {"isFired", true},
+                                                          {"isTriggered", true},
+                                                          {"join", false},
+                                                          {"last", false},
+                                                          {"max", true},
+                                                          {"min", true},
+                                                          {"neq", true},
+                                                          {"next", false},
+                                                          {"pop", false},
+                                                          {"pop_back", false},
+                                                          {"pop_front", false},
+                                                          {"prev", false},
+                                                          {"push", false},
+                                                          {"push_back", false},
+                                                          {"push_front", false},
+                                                          {"r_and", true},
+                                                          {"r_or", true},
+                                                          {"r_product", true},
+                                                          {"r_sum", true},
+                                                          {"r_xor", true},
+                                                          {"renew", false},
+                                                          {"renew_copy", false},
+                                                          {"resume", false},
+                                                          {"reverse", false},
+                                                          {"rsort", false},
+                                                          {"set", false},
+                                                          {"shuffle", false},
+                                                          {"size", true},
+                                                          {"slice", true},
+                                                          {"sliceBackBack", true},
+                                                          {"sliceFrontBack", true},
+                                                          {"sort", false},
+                                                          {"thisOr", false},
+                                                          {"trigger", false},
+                                                          {"unique", true},
+                                                          {"unique_index", true},
+                                                          {"word", true}};
+
+    auto isPureIt = isPureMethod.find(name());
+    UASSERT_OBJ(isPureIt != isPureMethod.end(), this, "Unknown purity of method " + name());
+    m_pure = isPureIt->second;
+}
 const char* AstCFunc::broken() const {
    BROKEN_RTN((m_scopep && !m_scopep->brokeExists()));
    return nullptr;
@@ -72,12 +72,12 @@ private:
    string m_unnamedScope;  // Name of begin blocks, including unnamed blocks
    int m_ifDepth = 0;  // Current if depth
    bool m_keepBegins = false;  // True if begins should not be inlined
-    std::set<AstVar*> m_staticFuncVars;  // Static variables from m_ftaskp

    // METHODS

    string dot(const string& a, const string& b) {
        if (a == "") return b;
+        if (b == "") return a;
        return a + "__DOT__" + b;
    }

@@ -123,30 +123,22 @@ private:
        }
    }

-    void renameAndStaticsRecurse(AstNode* const nodep) {
-        // Rename references and move InitialStatic items
-        if (AstVarRef* const varrefp = VN_CAST(nodep, VarRef)) {
-            const auto it = m_staticFuncVars.find(varrefp->varp());
-            if (it != m_staticFuncVars.end()) varrefp->name((*it)->name());
-        }
-
-        if (nodep->op1p()) renameAndStaticsRecurse(nodep->op1p());
-        if (nodep->op2p()) renameAndStaticsRecurse(nodep->op2p());
-        if (nodep->op3p()) renameAndStaticsRecurse(nodep->op3p());
-        if (nodep->op4p()) renameAndStaticsRecurse(nodep->op4p());
-        if (nodep->nextp()) renameAndStaticsRecurse(nodep->nextp());
-
-        if (VN_IS(nodep, InitialStatic)) {
-            nodep->unlinkFrBack();
-            m_ftaskp->addHereThisAsNext(nodep);
-        }
-    }
-
    // VISITORS
    void visit(AstFork* nodep) override {
-        // Keep this begin to group its statements together
+        // Keep begins in forks to group their statements together
        VL_RESTORER(m_keepBegins);
        m_keepBegins = true;
+        // If a statement is not a begin, wrap it in a begin. This fixes an issue when the
+        // statement is a task call that gets inlined later (or any other statement that gets
+        // replaced with multiple statements)
+        for (AstNode* stmtp = nodep->stmtsp(); stmtp; stmtp = stmtp->nextp()) {
+            if (!VN_IS(stmtp, Begin)) {
+                AstBegin* const beginp = new AstBegin{stmtp->fileline(), "", nullptr};
+                stmtp->replaceWith(beginp);
+                beginp->addStmtsp(stmtp);
+                stmtp = beginp;
+            }
+        }
        dotNames(nodep, "__FORK__");
        nodep->name("");
    }
@@ -186,7 +178,10 @@ private:
            m_ftaskp = nodep;
            m_liftedp = nullptr;
            iterateChildren(nodep);
-            renameAndStaticsRecurse(nodep);
+            nodep->foreach([&](AstInitialStatic* const initp) {
+                initp->unlinkFrBack();
+                m_ftaskp->addHereThisAsNext(initp);
+            });
            if (m_liftedp) {
                // Place lifted nodes at beginning of stmtsp, so Var nodes appear before referenced
                if (AstNode* const stmtsp = nodep->stmtsp()) {
@@ -196,7 +191,6 @@ private:
                nodep->addStmtsp(m_liftedp);
                m_liftedp = nullptr;
            }
-            m_staticFuncVars.clear();
            m_ftaskp = nullptr;
        }
    }
@@ -235,11 +229,11 @@ private:
    void visit(AstVar* nodep) override {
        // If static variable, move it outside a function.
        if (nodep->lifetime().isStatic() && m_ftaskp) {
-            const std::string newName = m_ftaskp->name() + "__Vstatic__" + nodep->name();
+            const std::string newName
+                = m_ftaskp->name() + "__Vstatic__" + dot(m_unnamedScope, nodep->name());
            nodep->name(newName);
            nodep->unlinkFrBack();
            m_ftaskp->addHereThisAsNext(nodep);
-            m_staticFuncVars.insert(nodep);
            nodep->funcLocal(false);
        } else if (m_unnamedScope != "") {
            // Rename it
@@ -288,7 +282,7 @@ private:
            // To keep correct visual order, must add before other Text's
            AstText* const afterp = nodep->scopeAttrp();
            if (afterp) afterp->unlinkFrBackWithNext();
-            nodep->addScopeAttrp(new AstText{nodep->fileline(), string("__DOT__") + scname});
+            nodep->addScopeAttrp(new AstText{nodep->fileline(), string{"__DOT__"} + scname});
            if (afterp) nodep->addScopeAttrp(afterp);
        }
        iterateChildren(nodep);
@@ -350,7 +344,6 @@ private:
    void visit(AstVarRef* nodep) override {
        if (nodep->varp()->user1()) {  // It was converted
            UINFO(9, "    relinVarRef " << nodep << endl);
-            nodep->name(nodep->varp()->name());
        }
        iterateChildren(nodep);
    }
@@ -381,5 +374,5 @@ void V3Begin::debeginAll(AstNetlist* nodep) {
        { BeginVisitor{nodep, &state}; }
        if (state.anyFuncInBegin()) { BeginRelinkVisitor{nodep, &state}; }
    }  // Destruct before checking
-    V3Global::dumpCheckGlobalTree("begin", 0, dumpTree() >= 3);
+    V3Global::dumpCheckGlobalTree("begin", 0, dumpTreeLevel() >= 3);
 }
@@ -38,17 +38,19 @@ VL_DEFINE_DEBUG_FUNCTIONS;
 //######################################################################
 // Branch state, as a visitor of each AstNode

-class BranchVisitor final : public VNVisitor {
+class BranchVisitor final : public VNVisitorConst {
 private:
    // NODE STATE
    // Entire netlist:
    //  AstFTask::user1()       -> int.  Number of references
    const VNUser1InUse m_inuser1;

-    // STATE
+    // STATE - across all visitors
+    std::vector<AstCFunc*> m_cfuncsp;  // List of all tasks
+
+    // STATE - for current visit position (use VL_RESTORER)
    int m_likely = false;  // Excuses for branch likely taken
    int m_unlikely = false;  // Excuses for branch likely not taken
-    std::vector<AstCFunc*> m_cfuncsp;  // List of all tasks

    // METHODS

@@ -71,12 +73,12 @@ private:
        {
            // Do if
            reset();
-            iterateAndNextNull(nodep->thensp());
+            iterateAndNextConstNull(nodep->thensp());
            const int ifLikely = m_likely;
            const int ifUnlikely = m_unlikely;
            // Do else
            reset();
-            iterateAndNextNull(nodep->elsesp());
+            iterateAndNextConstNull(nodep->elsesp());
            const int elseLikely = m_likely;
            const int elseUnlikely = m_unlikely;
            // Compute
@@ -91,16 +93,16 @@ private:
    void visit(AstNodeCCall* nodep) override {
        checkUnlikely(nodep);
        nodep->funcp()->user1Inc();
-        iterateChildren(nodep);
+        iterateChildrenConst(nodep);
    }
    void visit(AstCFunc* nodep) override {
        checkUnlikely(nodep);
        m_cfuncsp.push_back(nodep);
-        iterateChildren(nodep);
+        iterateChildrenConst(nodep);
    }
    void visit(AstNode* nodep) override {
        checkUnlikely(nodep);
-        iterateChildren(nodep);
+        iterateChildrenConst(nodep);
    }

    // METHODS
@@ -114,7 +116,7 @@ public:
    // CONSTRUCTORS
    explicit BranchVisitor(AstNetlist* nodep) {
        reset();
-        iterateChildren(nodep);
+        iterateChildrenConst(nodep);
        calc_tasks();
    }
    ~BranchVisitor() override = default;
@@ -62,6 +62,8 @@ public:
    }
 } s_brokenCntGlobal;

+static bool s_brokenAllowMidvisitorCheck = false;
+
 //######################################################################
 // Table of allocated AstNode pointers

@@ -144,23 +146,26 @@ bool V3Broken::isLinkable(const AstNode* nodep) { return s_linkableTable.isLinka
 //######################################################################
 // Check every node in tree

-class BrokenCheckVisitor final : public VNVisitor {
-    bool m_inScope = false;  // Under AstScope
-
+class BrokenCheckVisitor final : public VNVisitorConst {
    // Constants for marking we are under/not under a node
    const uint8_t m_brokenCntCurrentNotUnder = s_brokenCntGlobal.get();  // Top bit is clear
    const uint8_t m_brokenCntCurrentUnder = m_brokenCntCurrentNotUnder | 0x80;  // Top bit is set

-    // Current CFunc, if any
-    const AstCFunc* m_cfuncp = nullptr;
+    // STATE - across all visitors
    // All local variables declared in current function
-    std::unordered_set<const AstVar*> m_localVars;
+    std::set<const AstVar*> m_localVars;
    // Variable references in current function that do not reference an in-scope local
-    std::unordered_map<const AstVar*, const AstNodeVarRef*> m_suspectRefs;
+    std::map<const AstVar*, const AstNodeVarRef*> m_suspectRefs;
    // Local variables declared in the scope of the current statement
    std::vector<std::unordered_set<const AstVar*>> m_localsStack;

+    // STATE - for current visit position (use VL_RESTORER)
+    const AstCFunc* m_cfuncp = nullptr;  // Current CFunc, if any
+    bool m_inScope = false;  // Under AstScope
+    std::set<std::string> m_cFuncNames;  // CFunc by name in current class/module
+
 private:
+    // METHODS
    static void checkWidthMin(const AstNode* nodep) {
        UASSERT_OBJ(nodep->width() == nodep->widthMin()
                        || v3Global.widthMinUsage() != VWidthMinUsage::MATCHES_WIDTH,
@@ -172,6 +177,7 @@ private:
        const char* const whyp = nodep->broken();
        UASSERT_OBJ(!whyp, nodep,
                    "Broken link in node (or something without maybePointedTo): " << whyp);
+        if (!s_brokenAllowMidvisitorCheck) nodep->checkIter();
        if (nodep->dtypep()) {
            UASSERT_OBJ(nodep->dtypep()->brokeExists(), nodep,
                        "Broken link in node->dtypep() to " << cvtToHex(nodep->dtypep()));
@@ -217,6 +223,7 @@ private:
        }
        return false;
    }
+    // VISITORS
    void visit(AstNodeAssign* nodep) override {
        processAndIterate(nodep);
        UASSERT_OBJ(!(v3Global.assertDTypesResolved() && nodep->brokeLhsMustBeLvalue()
@@ -232,10 +239,20 @@ private:
    }
    void visit(AstScope* nodep) override {
        VL_RESTORER(m_inScope);
-        {
-            m_inScope = true;
-            processAndIterate(nodep);
-        }
+        m_inScope = true;
+        VL_RESTORER(m_cFuncNames);
+        m_cFuncNames.clear();
+        processAndIterate(nodep);
+    }
+    void visit(AstNodeModule* nodep) override {
+        VL_RESTORER(m_cFuncNames);
+        m_cFuncNames.clear();
+        processAndIterate(nodep);
+    }
+    void visit(AstNodeUOrStructDType* nodep) override {
+        VL_RESTORER(m_cFuncNames);
+        m_cFuncNames.clear();
+        processAndIterate(nodep);
    }
    void visit(AstNodeVarRef* nodep) override {
        processAndIterate(nodep);
@@ -257,12 +274,19 @@ private:
    }
    void visit(AstCFunc* nodep) override {
        UASSERT_OBJ(!m_cfuncp, nodep, "Nested AstCFunc");
+        VL_RESTORER(m_cfuncp);
        m_cfuncp = nodep;
        m_localVars.clear();
        m_suspectRefs.clear();
        m_localsStack.clear();
        pushLocalScope();

+        // Check for duplicate names, otherwise linker might just ignore them
+        string nameArgs = nodep->name();
+        if (!nodep->argTypes().empty()) nameArgs += "(" + nodep->argTypes() + ")";
+        UASSERT_OBJ(m_cFuncNames.emplace(nameArgs).second, nodep,
+                    "Duplicate cfunc name: '" << nameArgs << "'");
+
        processAndIterate(nodep);

        // Check suspect references are all to non-locals
@@ -270,8 +294,6 @@ private:
            UASSERT_OBJ(m_localVars.count(pair.first) == 0, pair.second,
                        "Local variable not in scope where referenced: " << pair.first);
        }
-
-        m_cfuncp = nullptr;
    }
    void visit(AstNodeIf* nodep) override {
        // Each branch is a separate local variable scope
@@ -312,7 +334,7 @@ private:

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

@@ -351,6 +373,8 @@ void V3Broken::brokenAll(AstNetlist* nodep) {
    }
 }

+void V3Broken::allowMidvisitorCheck(bool flag) { s_brokenAllowMidvisitorCheck = flag; }
+
 //######################################################################
 // Self test

@@ -32,6 +32,9 @@ public:
    static bool isLinkable(const AstNode* nodep);
    static void addNewed(const AstNode* nodep);
    static void deleted(const AstNode* nodep);
+    // Called on error to say may be inside visitor,
+    // Disables checks that may misfire if not called at stable point between visitors
+    static void allowMidvisitorCheck(bool flag);
    static void selfTest();
 };

@@ -70,7 +70,7 @@ private:
        funcp->slow(!m_type.isClass());  // Only classes construct on fast path
        string preventUnusedStmt;
        if (m_type.isClass()) {
-            funcp->argTypes(EmitCBaseVisitor::symClassVar());
+            funcp->argTypes(EmitCBase::symClassVar());
            preventUnusedStmt = "if (false && vlSymsp) {}  // Prevent unused\n";
        } else if (m_type.isCoverage()) {
            funcp->argTypes("bool first");
@@ -117,7 +117,7 @@ public:
                    callp->argTypes("vlSymsp");
                } else {
                    if (m_type.isCoverage()) callp->argTypes("first");
-                    callp->selfPointer("this");
+                    callp->selfPointer(VSelfPointerText{VSelfPointerText::This()});
                }
                rootFuncp->addStmtsp(callp->makeStmt());
            }
@@ -148,6 +148,7 @@ private:
        m_modp = nodep;
        V3CCtorsBuilder var_reset{nodep, "_ctor_var_reset",
                                  VN_IS(nodep, Class) ? VCtorType::CLASS : VCtorType::MODULE};
+        // cppcheck-suppress danglingLifetime
        m_varResetp = &var_reset;
        iterateChildren(nodep);

@@ -201,7 +202,7 @@ private:

 public:
    // CONSTRUCTORS
-    CCtorsVisitor(AstNode* nodep) { iterate(nodep); }
+    explicit CCtorsVisitor(AstNode* nodep) { iterate(nodep); }
    ~CCtorsVisitor() override = default;
 };

@@ -228,7 +229,7 @@ void V3CCtors::evalAsserts() {
                        // if (signal & CONST(upper_non_clean_mask)) { fail; }
                        AstVarRef* const vrefp
                            = new AstVarRef{varp->fileline(), varp, VAccess::READ};
-                        vrefp->selfPointer("this");
+                        vrefp->selfPointer(VSelfPointerText{VSelfPointerText::This()});
                        AstNodeExpr* newp = vrefp;
                        if (varp->isWide()) {
                            newp = new AstWordSel{
@@ -256,5 +257,5 @@ void V3CCtors::cctorsAll() {
    UINFO(2, __FUNCTION__ << ": " << endl);
    evalAsserts();
    { CCtorsVisitor{v3Global.rootp()}; }
-    V3Global::dumpCheckGlobalTree("cctors", 0, dumpTree() >= 3);
+    V3Global::dumpCheckGlobalTree("cctors", 0, dumpTreeLevel() >= 3);
 }
@@ -28,9 +28,11 @@
 #include "V3CUse.h"

 #include "V3Ast.h"
+#include "V3FileLine.h"
 #include "V3Global.h"

-#include <set>
+#include <map>
+#include <utility>

 VL_DEFINE_DEBUG_FUNCTIONS;

@@ -45,32 +47,32 @@ class CUseVisitor final : public VNVisitor {
    const VNUser1InUse m_inuser1;

    // MEMBERS
-    bool m_impOnly = false;  // In details needed only for implementation
    AstNodeModule* const m_modp;  // Current module
-    std::set<std::pair<VUseType, std::string>> m_didUse;  // What we already used
+    std::map<std::string, std::pair<FileLine*, VUseType>> m_didUse;  // What we already used

    // METHODS
    void addNewUse(AstNode* nodep, VUseType useType, const string& name) {
-        if (m_didUse.emplace(useType, name).second) {
-            AstCUse* const newp = new AstCUse{nodep->fileline(), useType, name};
-            m_modp->addStmtsp(newp);
-            UINFO(8, "Insert " << newp << endl);
+        auto e = m_didUse.emplace(name, std::make_pair(nodep->fileline(), useType));
+        if (e.second || ((e.first->second.second & useType) != useType)) {
+            e.first->second.second = e.first->second.second | useType;
        }
    }

    // VISITORS
    void visit(AstClassRefDType* nodep) override {
-        if (nodep->user1SetOnce()) return;  // Process once
-        if (!m_impOnly) addNewUse(nodep, VUseType::INT_FWD_CLASS, nodep->classp()->name());
-        // Need to include extends() when we implement, but no need for pointers to know
-        VL_RESTORER(m_impOnly);
-        {
-            m_impOnly = true;
-            iterateChildren(nodep->classp());  // This also gets all extend classes
-        }
+        addNewUse(nodep, VUseType::INT_FWD_CLASS, nodep->classp()->name());
+    }
+    void visit(AstCFunc* nodep) override {
+        if (nodep->user1SetOnce()) return;
+        iterateAndNextNull(nodep->argsp());
+        iterateAndNextNull(nodep->stmtsp());
+    }
+    void visit(AstCCall* nodep) override { return; }
+    void visit(AstCReturn* nodep) override {
+        UASSERT(!nodep->user1SetOnce(), "Visited same return twice.");
+        iterate(nodep->lhsp()->dtypep());
    }
    void visit(AstNodeDType* nodep) override {
-        if (nodep->user1SetOnce()) return;  // Process once
        if (nodep->virtRefDTypep()) iterate(nodep->virtRefDTypep());
        if (nodep->virtRefDType2p()) iterate(nodep->virtRefDType2p());

@@ -79,11 +81,13 @@ class CUseVisitor final : public VNVisitor {
        if (stypep && stypep->classOrPackagep()) {
            addNewUse(nodep, VUseType::INT_INCLUDE, stypep->classOrPackagep()->name());
            iterateChildren(stypep);
+        } else if (AstClassRefDType* const classp = VN_CAST(nodep->skipRefp(), ClassRefDType)) {
+            addNewUse(nodep, VUseType::INT_FWD_CLASS, classp->name());
        }
    }
    void visit(AstNode* nodep) override {
        if (nodep->user1SetOnce()) return;  // Process once
-        if (nodep->dtypep() && !nodep->dtypep()->user1()) iterate(nodep->dtypep());
+        if (nodep->dtypep()) iterate(nodep->dtypep());
        iterateChildren(nodep);
    }
    void visit(AstCell* nodep) override {
@@ -98,6 +102,12 @@ public:
    explicit CUseVisitor(AstNodeModule* modp)
        : m_modp(modp) {
        iterate(modp);
+
+        for (auto& used : m_didUse) {
+            AstCUse* const newp = new AstCUse{used.second.first, used.second.second, used.first};
+            m_modp->addStmtsp(newp);
+            UINFO(8, "Insert " << newp << endl);
+        }
    }
    ~CUseVisitor() override = default;
    VL_UNCOPYABLE(CUseVisitor);
@@ -115,5 +125,5 @@ void V3CUse::cUseAll() {
        // for each output file and put under that
        CUseVisitor{modp};
    }
-    V3Global::dumpCheckGlobalTree("cuse", 0, dumpTree() >= 3);
+    V3Global::dumpCheckGlobalTree("cuse", 0, dumpTreeLevel() >= 3);
 }
@@ -53,7 +53,7 @@ VL_DEFINE_DEBUG_FUNCTIONS;

 //######################################################################

-class CaseLintVisitor final : public VNVisitor {
+class CaseLintVisitor final : public VNVisitorConst {
 private:
    const AstNodeCase* m_caseExprp
        = nullptr;  // Under a CASE value node, if so the relevant case statement
@@ -79,10 +79,10 @@ private:
        // Check for X/Z in non-casex statements
        {
            m_caseExprp = nodep;
-            iterate(nodep->exprp());
+            iterateConst(nodep->exprp());
            for (AstCaseItem* itemp = nodep->itemsp(); itemp;
                 itemp = VN_AS(itemp->nextp(), CaseItem)) {
-                iterateAndNextNull(itemp->condsp());
+                iterateAndNextConstNull(itemp->condsp());
            }
            m_caseExprp = nullptr;
        }
@@ -108,11 +108,11 @@ private:
            }
        }
    }
-    void visit(AstNode* nodep) override { iterateChildren(nodep); }
+    void visit(AstNode* nodep) override { iterateChildrenConst(nodep); }

 public:
    // CONSTRUCTORS
-    explicit CaseLintVisitor(AstNodeCase* nodep) { iterate(nodep); }
+    explicit CaseLintVisitor(AstNodeCase* nodep) { iterateConst(nodep); }
    ~CaseLintVisitor() override = default;
 };

@@ -139,32 +139,42 @@ private:
    std::array<AstNode*, 1 << CASE_OVERLAP_WIDTH> m_valueItem;

    // METHODS
-    bool caseIsEnumComplete(AstCase* nodep, uint32_t numCases) {
-        // Return true if case is across an enum, and every value in the case
-        // statement corresponds to one of the enum values
-        if (!nodep->uniquePragma() && !nodep->unique0Pragma()) return false;
-        AstEnumDType* const enumDtp
+    //! Determine whether we should check case items are complete
+    //! @return  Enum's dtype if should check, nullptr if shouldn't
+    const AstEnumDType* getEnumCompletionCheckDType(const AstCase* const nodep) {
+        if (!nodep->uniquePragma() && !nodep->unique0Pragma()) return nullptr;
+        const AstEnumDType* const enumDtp
            = VN_CAST(nodep->exprp()->dtypep()->skipRefToEnump(), EnumDType);
-        if (!enumDtp) return false;  // Case isn't enum
-        AstBasicDType* const basicp = enumDtp->subDTypep()->basicp();
-        if (!basicp) return false;  // Not simple type (perhaps IEEE illegal)
-        if (basicp->width() > 32) return false;
-        // Find all case values into a set
-        std::set<uint32_t> caseSet;
-        for (uint32_t i = 0; i < numCases; ++i) {  // All case items
-            if (m_valueItem[i]) caseSet.emplace(i);
-        }
-        // Find all enum values into a set
-        std::set<uint32_t> enumSet;
-        for (AstEnumItem* itemp = enumDtp->itemsp(); itemp;
+        if (!enumDtp) return nullptr;  // Case isn't enum
+        const AstBasicDType* const basicp = enumDtp->subDTypep()->basicp();
+        if (!basicp) return nullptr;  // Not simple type (perhaps IEEE illegal)
+        if (basicp->width() > 32) return nullptr;
+        return enumDtp;
+    }
+    //! @return  True if case items are complete, false if there are uncovered enums
+    bool checkCaseEnumComplete(const AstCase* const nodep, const AstEnumDType* const dtype) {
+        const uint32_t numCases = 1UL << m_caseWidth;
+        for (AstEnumItem* itemp = dtype->itemsp(); itemp;
             itemp = VN_AS(itemp->nextp(), EnumItem)) {
            AstConst* const econstp = VN_AS(itemp->valuep(), Const);
-            const uint32_t val = econstp->toUInt();
-            // UINFO(9, "Complete enum item " << val << ": " << itemp << endl);
-            enumSet.emplace(val);
+            V3Number nummask{itemp, econstp->width()};
+            nummask.opBitsNonX(econstp->num());
+            const uint32_t mask = nummask.toUInt();
+            V3Number numval{itemp, econstp->width()};
+            numval.opBitsOne(econstp->num());
+            const uint32_t val = numval.toUInt();
+
+            for (uint32_t i = 0; i < numCases; ++i) {
+                if ((i & mask) == val) {
+                    if (!m_valueItem[i]) {
+                        nodep->v3warn(CASEINCOMPLETE, "Enum item " << itemp->prettyNameQ()
+                                                                   << " not covered by case\n");
+                        return false;  // enum has uncovered value by case items
+                    }
+                }
+            }
        }
-        // If sets match, all covered
-        return (caseSet == enumSet);
+        return true;  // enum is fully covered
    }
    bool isCaseTreeFast(AstCase* nodep) {
        int width = 0;
@@ -193,6 +203,8 @@ private:
        // We can cheat and use uint32_t's because we only support narrow case's
        bool reportedOverlap = false;
        bool reportedSubcase = false;
+        bool hasDefaultCase = false;
+        std::map<AstNode*, AstCaseItem*> caseItemMap;  // case condition -> case item
        for (AstCaseItem* itemp = nodep->itemsp(); itemp;
             itemp = VN_AS(itemp->nextp(), CaseItem)) {
            for (AstNode* icondp = itemp->condsp(); icondp; icondp = icondp->nextp()) {
@@ -202,6 +214,7 @@ private:
                if (neverItem(nodep, iconstp)) {
                    // X in casez can't ever be executed
                } else {
+                    const bool isCondWildcard = iconstp->num().isAnyXZ();
                    V3Number nummask{itemp, iconstp->width()};
                    nummask.opBitsNonX(iconstp->num());
                    const uint32_t mask = nummask.toUInt();
@@ -210,16 +223,17 @@ private:
                    const uint32_t val = numval.toUInt();

                    uint32_t firstOverlap = 0;
-                    bool foundOverlap = false;
+                    AstNode* overlappedCondp = nullptr;
                    bool foundHit = false;
                    for (uint32_t i = 0; i < numCases; ++i) {
                        if ((i & mask) == val) {
                            if (!m_valueItem[i]) {
-                                m_valueItem[i] = itemp;
+                                m_valueItem[i] = icondp;
+                                caseItemMap[icondp] = itemp;
                                foundHit = true;
-                            } else if (!foundOverlap) {
+                            } else if (!overlappedCondp) {
                                firstOverlap = i;
-                                foundOverlap = true;
+                                overlappedCondp = m_valueItem[i];
                                m_caseNoOverlapsAllCovered = false;
                            }
                        }
@@ -227,9 +241,19 @@ private:
                    if (!nodep->priorityPragma()) {
                        // If this case statement doesn't have the priority
                        // keyword, we want to warn on any overlap.
-                        if (!reportedOverlap && foundOverlap) {
-                            icondp->v3warn(CASEOVERLAP, "Case values overlap (example pattern 0x"
-                                                            << std::hex << firstOverlap << ")");
+                        if (!reportedOverlap && overlappedCondp) {
+                            std::ostringstream examplePattern;
+                            if (isCondWildcard) {
+                                examplePattern << " (example pattern 0x" << std::hex
+                                               << firstOverlap << ")";
+                            }
+                            icondp->v3warn(CASEOVERLAP,
+                                           "Case conditions overlap"
+                                               << examplePattern.str() << "\n"
+                                               << icondp->warnContextPrimary() << '\n'
+                                               << overlappedCondp->warnOther()
+                                               << "... Location of overlapping condition\n"
+                                               << overlappedCondp->warnContextSecondary());
                            reportedOverlap = true;
                        }
                    } else {
@@ -240,7 +264,11 @@ private:
                        if (!reportedSubcase && !foundHit) {
                            icondp->v3warn(CASEOVERLAP,
                                           "Case item ignored: every matching value is covered "
-                                           "by an earlier item");
+                                           "by an earlier condition\n"
+                                               << icondp->warnContextPrimary() << '\n'
+                                               << overlappedCondp->warnOther()
+                                               << "... Location of previous condition\n"
+                                               << overlappedCondp->warnContextPrimary());
                            reportedSubcase = true;
                        }
                    }
@@ -251,17 +279,28 @@ private:
                for (uint32_t i = 0; i < numCases; ++i) {
                    if (!m_valueItem[i]) m_valueItem[i] = itemp;
                }
+                caseItemMap[itemp] = itemp;
+                hasDefaultCase = true;
            }
        }
-        if (!caseIsEnumComplete(nodep, numCases)) {
-            for (uint32_t i = 0; i < numCases; ++i) {
-                if (!m_valueItem[i]) {
-                    nodep->v3warn(CASEINCOMPLETE, "Case values incompletely covered "
-                                                  "(example pattern 0x"
-                                                      << std::hex << i << ")");
+        if (!hasDefaultCase) {
+            const AstEnumDType* const dtype = getEnumCompletionCheckDType(nodep);
+            if (dtype) {
+                if (!checkCaseEnumComplete(nodep, dtype)) {
+                    // checkCaseEnumComplete has already warned of incompletion
                    m_caseNoOverlapsAllCovered = false;
                    return false;
                }
+            } else {
+                for (uint32_t i = 0; i < numCases; ++i) {
+                    if (!m_valueItem[i]) {  // has uncovered case
+                        nodep->v3warn(CASEINCOMPLETE, "Case values incompletely covered "
+                                                      "(example pattern 0x"
+                                                          << std::hex << i << ")");
+                        m_caseNoOverlapsAllCovered = false;
+                        return false;
+                    }
+                }
            }
        }

@@ -274,8 +313,10 @@ private:
        // Convert valueItem from AstCaseItem* to the expression
        // Not done earlier, as we may now have a nullptr because it's just a ";" NOP branch
        for (uint32_t i = 0; i < numCases; ++i) {
-            if (AstCaseItem* const itemp = VN_AS(m_valueItem[i], CaseItem)) {
-                m_valueItem[i] = itemp->stmtsp();
+            if (AstNode* const condp = m_valueItem[i]) {
+                AstCaseItem* caseItemp = caseItemMap[condp];
+                UASSERT(caseItemp, "caseItemp should exist");
+                m_valueItem[i] = caseItemp->stmtsp();
            }
        }
        return true;  // All is fine
@@ -543,10 +584,12 @@ private:
        }
    }
    //--------------------
-    void visit(AstNode* nodep) override {
-        if (VN_IS(nodep, Always)) m_alwaysp = nodep;
+    void visit(AstAlways* nodep) override {
+        VL_RESTORER(m_alwaysp)
+        m_alwaysp = nodep;
        iterateChildren(nodep);
    }
+    void visit(AstNode* nodep) override { iterateChildren(nodep); }

 public:
    // CONSTRUCTORS
@@ -566,7 +609,7 @@ public:
 void V3Case::caseAll(AstNetlist* nodep) {
    UINFO(2, __FUNCTION__ << ": " << endl);
    { CaseVisitor{nodep}; }  // Destruct before checking
-    V3Global::dumpCheckGlobalTree("case", 0, dumpTree() >= 3);
+    V3Global::dumpCheckGlobalTree("case", 0, dumpTreeLevel() >= 3);
 }
 void V3Case::caseLint(AstNodeCase* nodep) {
    UINFO(4, __FUNCTION__ << ": " << endl);
@@ -122,6 +122,31 @@ private:
        if (nodep->sizeMattersLhs()) ensureCast(nodep->lhsp());
        if (nodep->sizeMattersRhs()) ensureCast(nodep->rhsp());
    }
+    void visit(AstNodeCond* nodep) override {
+        // All class types are castable to each other. If they are of different types,
+        // a compilation error will be thrown, so an explicit cast is required. Types were
+        // already checked by V3Width and dtypep of a condition operator is a type of their
+        // common base class, so both classes can be safetly casted.
+        const AstClassRefDType* const thenClassDtypep
+            = VN_CAST(nodep->thenp()->dtypep(), ClassRefDType);
+        const AstClassRefDType* const elseClassDtypep
+            = VN_CAST(nodep->elsep()->dtypep(), ClassRefDType);
+        const bool castRequired = thenClassDtypep && elseClassDtypep
+                                  && (thenClassDtypep->classp() != elseClassDtypep->classp());
+        if (castRequired) {
+            const AstClass* const commonBaseClassp
+                = VN_AS(nodep->dtypep(), ClassRefDType)->classp();
+            if (thenClassDtypep->classp() != commonBaseClassp) {
+                AstNodeExpr* thenp = nodep->thenp()->unlinkFrBack();
+                nodep->thenp(new AstCCast{thenp->fileline(), thenp, nodep});
+            }
+            if (elseClassDtypep->classp() != commonBaseClassp) {
+                AstNodeExpr* elsep = nodep->elsep()->unlinkFrBack();
+                nodep->elsep(new AstCCast{elsep->fileline(), elsep, nodep});
+            }
+        }
+        visit(static_cast<AstNodeTriop*>(nodep));
+    }
    void visit(AstNodeTriop* nodep) override {
        iterateChildren(nodep);
        nodep->user1(nodep->lhsp()->user1() | nodep->rhsp()->user1() | nodep->thsp()->user1());
@@ -161,7 +186,8 @@ private:
            && !VN_IS(backp, NodeCCall) && !VN_IS(backp, CMethodHard) && !VN_IS(backp, SFormatF)
            && !VN_IS(backp, ArraySel) && !VN_IS(backp, StructSel) && !VN_IS(backp, RedXor)
            && (nodep->varp()->basicp() && !nodep->varp()->basicp()->isTriggerVec()
-                && !nodep->varp()->basicp()->isForkSync())
+                && !nodep->varp()->basicp()->isForkSync()
+                && !nodep->varp()->basicp()->isProcessRef())
            && backp->width() && castSize(nodep) != castSize(nodep->varp())) {
            // Cast vars to IData first, else below has upper bits wrongly set
            //  CData x=3; out = (QData)(x<<30);
@@ -208,5 +234,5 @@ public:
 void V3Cast::castAll(AstNetlist* nodep) {
    UINFO(2, __FUNCTION__ << ": " << endl);
    { CastVisitor{nodep}; }  // Destruct before checking
-    V3Global::dumpCheckGlobalTree("cast", 0, dumpTree() >= 3);
+    V3Global::dumpCheckGlobalTree("cast", 0, dumpTreeLevel() >= 3);
 }
@@ -27,6 +27,7 @@

 #include "V3Ast.h"
 #include "V3Global.h"
+#include "V3UniqueNames.h"

 VL_DEFINE_DEBUG_FUNCTIONS;

@@ -41,6 +42,7 @@ private:

    // MEMBERS
    string m_prefix;  // String prefix to add to name based on hier
+    V3UniqueNames m_names;  // For unique naming of structs and unions
    AstNodeModule* m_modp = nullptr;  // Current module
    AstNodeModule* m_classPackagep = nullptr;  // Package moving into
    const AstScope* m_classScopep = nullptr;  // Package moving scopes into
@@ -62,8 +64,10 @@ private:
        AstClassPackage* const packagep
            = new AstClassPackage{nodep->fileline(), nodep->origName()};
        packagep->name(nodep->name() + "__Vclpkg");
+        nodep->editCountInc();
        nodep->classOrPackagep(packagep);
        packagep->classp(nodep);
+        packagep->timeunit(nodep->timeunit());
        v3Global.rootp()->addModulesp(packagep);
        // Add package to hierarchy
        AstCell* const cellp = new AstCell{packagep->fileline(),
@@ -102,7 +106,6 @@ private:
            m_prefix = nodep->name() + "__02e";  // .
            iterateChildren(nodep);
        }
-        nodep->repairCache();
    }
    void visit(AstNodeModule* nodep) override {
        // Visit for NodeModules that are not AstClass (AstClass is-a AstNodeModule)
@@ -177,14 +180,15 @@ private:
    }

    void setStructModulep(AstNodeUOrStructDType* const dtypep) {
-        // Give it a pointer to its package and a final name
-        dtypep->classOrPackagep(m_modp);
-        dtypep->name(dtypep->name() + (VN_IS(dtypep, UnionDType) ? "__union" : "__struct")
-                     + cvtToStr(dtypep->uniqueNum()));
+        // Give struct a pointer to its package and a final name
+        dtypep->editCountInc();
+        dtypep->classOrPackagep(m_classPackagep ? m_classPackagep : m_modp);
+        dtypep->name(
+            m_names.get(dtypep->name() + (VN_IS(dtypep, UnionDType) ? "__union" : "__struct")));

        for (const AstMemberDType* itemp = dtypep->membersp(); itemp;
             itemp = VN_AS(itemp->nextp(), MemberDType)) {
-            AstNodeUOrStructDType* const subp = VN_CAST(itemp->skipRefp(), NodeUOrStructDType);
+            AstNodeUOrStructDType* const subp = itemp->getChildStructp();
            // Recurse only into anonymous unpacked structs inside this definition,
            // other unpacked structs will be reached from another typedefs
            if (subp && !subp->packed() && subp->name().empty()) setStructModulep(subp);
@@ -193,6 +197,7 @@ private:
    void visit(AstTypedef* nodep) override {
        if (nodep->user1SetOnce()) return;
        iterateChildren(nodep);
+        if (m_classPackagep) m_classPackagep->addStmtsp(nodep->unlinkFrBack());

        AstNodeUOrStructDType* const dtypep = VN_CAST(nodep->dtypep(), NodeUOrStructDType);
        if (dtypep && !dtypep->packed()) {
@@ -243,5 +248,5 @@ public:
 void V3Class::classAll(AstNetlist* nodep) {
    UINFO(2, __FUNCTION__ << ": " << endl);
    { ClassVisitor{nodep}; }  // Destruct before checking
-    V3Global::dumpCheckGlobalTree("class", 0, dumpTree() >= 3);
+    V3Global::dumpCheckGlobalTree("class", 0, dumpTreeLevel() >= 3);
 }
@@ -95,6 +95,7 @@ private:
                || VN_IS(nodep->dtypep()->skipRefp(), DynArrayDType)
                || VN_IS(nodep->dtypep()->skipRefp(), ClassRefDType)
                || VN_IS(nodep->dtypep()->skipRefp(), QueueDType)
+                || VN_IS(nodep->dtypep()->skipRefp(), StreamDType)
                || VN_IS(nodep->dtypep()->skipRefp(), UnpackArrayDType)
                || VN_IS(nodep->dtypep()->skipRefp(), VoidDType)) {
            } else {
@@ -298,7 +299,11 @@ private:
    }
    void visit(AstWith* nodep) override {
        iterateChildren(nodep);
-        ensureCleanAndNext(nodep->exprp());
+        setClean(nodep, true);
+    }
+    void visit(AstCReturn* nodep) override {
+        iterateChildren(nodep);
+        ensureClean(nodep->lhsp());
        setClean(nodep, true);
    }
    void visit(AstIntfRef* nodep) override {
@@ -325,5 +330,5 @@ public:
 void V3Clean::cleanAll(AstNetlist* nodep) {
    UINFO(2, __FUNCTION__ << ": " << endl);
    { CleanVisitor{nodep}; }  // Destruct before checking
-    V3Global::dumpCheckGlobalTree("clean", 0, dumpTree() >= 3);
+    V3Global::dumpCheckGlobalTree("clean", 0, dumpTreeLevel() >= 3);
 }
@@ -95,7 +95,7 @@ private:
        if (vscp->user1p()) return VN_AS(vscp->user1p(), VarScope);
        const AstVar* const varp = vscp->varp();
        const string newvarname
-            = string("__Vsampled__") + vscp->scopep()->nameDotless() + "__" + varp->name();
+            = string{"__Vsampled__"} + vscp->scopep()->nameDotless() + "__" + varp->name();
        FileLine* const flp = vscp->fileline();
        AstVar* const newvarp = new AstVar{flp, VVarType::MODULETEMP, newvarname, varp->dtypep()};
        newvarp->noReset(true);  // Reset by below assign
@@ -146,17 +146,19 @@ private:
        UASSERT_OBJ(nodep->hasClocked(), nodep, "Should have been converted by V3Sched");
        UASSERT_OBJ(nodep->stmtsp(), nodep, "Should not have been created if empty");

-        VNRelinker relinker;
-        nodep->unlinkFrBack(&relinker);
        AstNode* const stmtsp = nodep->stmtsp()->unlinkFrBackWithNext();

        // Create 'if' statement, if needed
        if (!m_lastSenp || !nodep->sensesp()->sameTree(m_lastSenp)) {
+            VNRelinker relinker;
+            nodep->unlinkFrBack(&relinker);
            clearLastSen();
            m_lastSenp = nodep->sensesp();
            // Make a new if statement
            m_lastIfp = makeActiveIf(m_lastSenp);
            relinker.relink(m_lastIfp);
+        } else {
+            nodep->unlinkFrBack();
        }

        // Move statements to if
@@ -222,5 +224,5 @@ public:
 void V3Clock::clockAll(AstNetlist* nodep) {
    UINFO(2, __FUNCTION__ << ": " << endl);
    { ClockVisitor{nodep}; }  // Destruct before checking
-    V3Global::dumpCheckGlobalTree("clock", 0, dumpTree() >= 3);
+    V3Global::dumpCheckGlobalTree("clock", 0, dumpTreeLevel() >= 3);
 }
@@ -238,5 +238,5 @@ public:
 void V3Combine::combineAll(AstNetlist* nodep) {
    UINFO(2, __FUNCTION__ << ": " << endl);
    CombineVisitor::apply(nodep);
-    V3Global::dumpCheckGlobalTree("combine", 0, dumpTree() >= 3);
+    V3Global::dumpCheckGlobalTree("combine", 0, dumpTreeLevel() >= 3);
 }
@@ -37,7 +37,7 @@ VL_DEFINE_DEBUG_FUNCTIONS;
 static void makeVlToString(AstClass* nodep) {
    AstCFunc* const funcp
        = new AstCFunc{nodep->fileline(), "VL_TO_STRING", nullptr, "std::string"};
-    funcp->argTypes("const VlClassRef<" + EmitCBaseVisitor::prefixNameProtect(nodep) + ">& obj");
+    funcp->argTypes("const VlClassRef<" + EmitCBase::prefixNameProtect(nodep) + ">& obj");
    funcp->isMethod(false);
    funcp->isConst(false);
    funcp->isStatic(false);
@@ -51,7 +51,7 @@ static void makeVlToString(AstClass* nodep) {
 static void makeVlToString(AstIface* nodep) {
    AstCFunc* const funcp
        = new AstCFunc{nodep->fileline(), "VL_TO_STRING", nullptr, "std::string"};
-    funcp->argTypes("const " + EmitCBaseVisitor::prefixNameProtect(nodep) + "* obj");
+    funcp->argTypes("const " + EmitCBase::prefixNameProtect(nodep) + "* obj");
    funcp->isMethod(false);
    funcp->isConst(false);
    funcp->isStatic(false);
@@ -63,9 +63,10 @@ static void makeVlToString(AstIface* nodep) {
 }
 static void makeVlToString(AstNodeUOrStructDType* nodep) {
    AstNodeModule* const modp = nodep->classOrPackagep();
+    UASSERT_OBJ(modp, nodep, "Unlinked struct package");
    AstCFunc* const funcp
        = new AstCFunc{nodep->fileline(), "VL_TO_STRING", nullptr, "std::string"};
-    funcp->argTypes("const " + EmitCBaseVisitor::prefixNameProtect(nodep) + "& obj");
+    funcp->argTypes("const " + EmitCBase::prefixNameProtect(nodep) + "& obj");
    funcp->isMethod(false);
    funcp->isConst(false);
    funcp->isStatic(false);
@@ -81,11 +82,13 @@ static void makeVlToString(AstNodeUOrStructDType* nodep) {
        }
        stmt += VIdProtect::protect(itemp->prettyName()) + ":\" + ";
        if (VN_IS(itemp->dtypep()->skipRefp(), BasicDType) && itemp->isWide()) {
-            stmt += "VL_TO_STRING_W";
+            stmt += "VL_TO_STRING_W(";
+            stmt += cvtToStr(itemp->widthWords());
+            stmt += ", ";
        } else {
-            stmt += "VL_TO_STRING";
+            stmt += "VL_TO_STRING(";
        }
-        stmt += "(obj." + itemp->nameProtect() + ");\n";
+        stmt += "obj." + itemp->nameProtect() + ");\n";
        funcp->addStmtsp(new AstCStmt{nodep->fileline(), stmt});
    }
    funcp->addStmtsp(new AstCStmt{nodep->fileline(), "out += \"}\";\n"});
@@ -137,7 +140,7 @@ static void makeToStringMiddle(AstClass* nodep) {
        string stmt = "out += ";
        if (!comma.empty()) stmt += "\", \"+ ";
        // comma = ", ";  // Nothing further so not needed
-        stmt += EmitCBaseVisitor::prefixNameProtect(nodep->extendsp()->dtypep());
+        stmt += EmitCBase::prefixNameProtect(nodep->extendsp()->dtypep());
        stmt += "::to_string_middle();\n";
        nodep->user1(true);  // So what we extend dumps this
        funcp->addStmtsp(new AstCStmt{nodep->fileline(), stmt});
@@ -172,5 +175,5 @@ void V3Common::commonAll() {
            if (!dtypep->packed()) makeVlToString(dtypep);
        }
    }
-    V3Global::dumpCheckGlobalTree("common", 0, dumpTree() >= 3);
+    V3Global::dumpCheckGlobalTree("common", 0, dumpTreeLevel() >= 3);
 }
@@ -40,25 +40,31 @@ template <typename T>
 class V3ConfigWildcardResolver final {
    using Map = std::map<const std::string, T>;

-    Map m_mapWildcard;  // Wildcard strings to entities
-    Map m_mapResolved;  // Resolved strings to converged entities
+    mutable V3Mutex m_mutex;  // protects members
+    Map m_mapWildcard VL_GUARDED_BY(m_mutex);  // Wildcard strings to entities
+    Map m_mapResolved VL_GUARDED_BY(m_mutex);  // Resolved strings to converged entities
 public:
    V3ConfigWildcardResolver() = default;
    ~V3ConfigWildcardResolver() = default;

    /// Update into maps from other
-    void update(const V3ConfigWildcardResolver& other) {
+    void update(const V3ConfigWildcardResolver& other) VL_MT_SAFE_EXCLUDES(m_mutex)
+        VL_EXCLUDES(other.m_mutex) {
+        V3LockGuard lock{m_mutex};
+        V3LockGuard otherLock{other.m_mutex};
        for (const auto& itr : other.m_mapResolved) m_mapResolved[itr.first].update(itr.second);
        for (const auto& itr : other.m_mapWildcard) m_mapWildcard[itr.first].update(itr.second);
    }

    // Access and create a (wildcard) entity
-    T& at(const string& name) {
+    T& at(const string& name) VL_MT_SAFE_EXCLUDES(m_mutex) {
+        V3LockGuard lock{m_mutex};
        // Don't store into wildcards if the name is not a wildcard string
        return m_mapWildcard[name];
    }
    // Access an entity and resolve wildcards that match it
-    T* resolve(const string& name) {
+    T* resolve(const string& name) VL_MT_SAFE_EXCLUDES(m_mutex) {
+        V3LockGuard lock{m_mutex};
        // Lookup if it was resolved before, typically not
        auto it = m_mapResolved.find(name);
        if (VL_UNLIKELY(it != m_mapResolved.end())) return &it->second;
@@ -78,7 +84,10 @@ public:
        return newp;
    }
    // Flush on update
-    void flush() { m_mapResolved.clear(); }
+    void flush() VL_MT_SAFE_EXCLUDES(m_mutex) {
+        V3LockGuard lock{m_mutex};
+        m_mapResolved.clear();
+    }
 };

 // Only public_flat_rw has the sensitity tree
@@ -23,6 +23,7 @@
 #include "V3Ast.h"
 #include "V3Error.h"
 #include "V3FileLine.h"
+#include "V3Mutex.h"

 //######################################################################

@@ -70,7 +70,7 @@ static int countTrailingZeroes(uint64_t val) {
 // This visitor can be used in the post-expanded Ast from V3Expand, where the Ast satisfies:
 // - Constants are 64 bit at most (because words are accessed via AstWordSel)
 // - Variables are scoped.
-class ConstBitOpTreeVisitor final : public VNVisitor {
+class ConstBitOpTreeVisitor final : public VNVisitorConst {
    // NODE STATE
    // AstVarRef::user4u      -> Base index of m_varInfos that points VarInfo
    // AstVarScope::user4u    -> Same as AstVarRef::user4
@@ -416,7 +416,7 @@ class ConstBitOpTreeVisitor final : public VNVisitor {
        {
            VL_RESTORER(m_leafp);
            m_leafp = &info;
-            iterate(nodep);
+            iterateConst(nodep);
        }

        bool ok = !m_failed;
@@ -431,7 +431,7 @@ class ConstBitOpTreeVisitor final : public VNVisitor {
    // VISITORS
    void visit(AstNode* nodep) override { CONST_BITOP_SET_FAILED("Hit unexpected op", nodep); }
    void visit(AstCCast* nodep) override {
-        iterateChildren(nodep);
+        iterateChildrenConst(nodep);
        if (m_leafp) m_leafp->updateBitRange(nodep);
    }
    void visit(AstShiftR* nodep) override {
@@ -440,7 +440,7 @@ class ConstBitOpTreeVisitor final : public VNVisitor {
        CONST_BITOP_RETURN_IF(!constp, nodep->rhsp());
        m_lsb += constp->toUInt();
        incrOps(nodep, __LINE__);
-        iterate(nodep->lhsp());
+        iterateConst(nodep->lhsp());
        m_leafp->updateBitRange(nodep);
        m_lsb -= constp->toUInt();
    }
@@ -449,12 +449,10 @@ class ConstBitOpTreeVisitor final : public VNVisitor {
        AstNode* lhsp = nodep->lhsp();
        AstCCast* const castp = VN_CAST(lhsp, CCast);
        if (castp) lhsp = castp->lhsp();
-        CONST_BITOP_RETURN_IF(!VN_IS(lhsp, VarRef) && !VN_IS(lhsp, Xor) && !VN_IS(lhsp, RedXor)
-                                  && !VN_IS(lhsp, ShiftR),
-                              lhsp);
+        CONST_BITOP_RETURN_IF(!isXorTree() && !VN_IS(lhsp, VarRef) && !VN_IS(lhsp, ShiftR), lhsp);
        incrOps(nodep, __LINE__);
        m_polarity = !m_polarity;
-        iterateChildren(nodep);
+        iterateChildrenConst(nodep);
        // Don't restore m_polarity for Xor as it counts parity of the entire tree
        if (!isXorTree()) m_polarity = !m_polarity;
        if (m_leafp && castp) m_leafp->updateBitRange(castp);
@@ -465,7 +463,7 @@ class ConstBitOpTreeVisitor final : public VNVisitor {
        CONST_BITOP_RETURN_IF(!constp, nodep->rhsp());
        UASSERT_OBJ(m_leafp->wordIdx() == -1, nodep, "Unexpected nested WordSel");
        m_leafp->wordIdx(constp->toSInt());
-        iterate(nodep->fromp());
+        iterateConst(nodep->fromp());
    }
    void visit(AstVarRef* nodep) override {
        CONST_BITOP_RETURN_IF(!m_leafp, nodep);
@@ -529,7 +527,7 @@ class ConstBitOpTreeVisitor final : public VNVisitor {
            // Always reach past a plain making AND
            Restorer restorer{*this};
            incrOps(nodep, __LINE__);
-            iterate(nodep->rhsp());
+            iterateConst(nodep->rhsp());
            CONST_BITOP_RETURN_IF(m_failed, nodep->rhsp());
            restorer.disableRestore();  // Now all checks passed
        } else if (nodep->type() == m_rootp->type()) {  // And, Or, Xor
@@ -542,13 +540,14 @@ class ConstBitOpTreeVisitor final : public VNVisitor {
                m_leafp = &leafInfo;
                AstNodeExpr* opp = right ? nodep->rhsp() : nodep->lhsp();
                const bool origFailed = m_failed;
-                iterate(opp);
+                iterateConst(opp);
                if (leafInfo.constp() || m_failed) {
                    // Revert changes in leaf
                    restorer.restoreNow();
                    // Reach past a cast then add to frozen nodes to be added to final reduction
                    if (const AstCCast* const castp = VN_CAST(opp, CCast)) opp = castp->lhsp();
-                    m_frozenNodes.emplace_back(opp, FrozenNodeInfo{m_polarity, m_lsb});
+                    const bool pol = isXorTree() || m_polarity;  // Only AND/OR tree needs polarity
+                    m_frozenNodes.emplace_back(opp, FrozenNodeInfo{pol, m_lsb});
                    m_failed = origFailed;
                    continue;
                }
@@ -647,11 +646,11 @@ class ConstBitOpTreeVisitor final : public VNVisitor {
        m_varInfos.push_back(nullptr);
        CONST_BITOP_RETURN_IF(!isAndTree() && !isOrTree() && !isXorTree(), nodep);
        if (AstNodeBiop* const biopp = VN_CAST(nodep, NodeBiop)) {
-            iterate(biopp);
+            iterateConst(biopp);
        } else {
            UASSERT_OBJ(VN_IS(nodep, RedXor), nodep, "Must be RedXor");
            incrOps(nodep, __LINE__);
-            iterateChildren(nodep);
+            iterateChildrenConst(nodep);
        }
        for (auto&& entry : m_bitPolarities) {
            getVarInfo(entry.m_info).setPolarity(entry.m_polarity, entry.m_bit);
@@ -1800,7 +1799,7 @@ private:
        UASSERT_OBJ((rstart + rwidth) == lstart, nodep,
                    "tried to merge two selects which are not adjacent");
        AstSel* const newselp = new AstSel{
-            lselp->fromp()->fileline(), rselp->fromp()->cloneTree(false), rstart, lwidth + rwidth};
+            lselp->fromp()->fileline(), rselp->fromp()->unlinkFrBack(), rstart, lwidth + rwidth};
        UINFO(5, "merged two adjacent sel " << lselp << " and " << rselp << " to one " << newselp
                                            << endl);

@@ -1810,6 +1809,7 @@ private:
        VL_DO_DANGLING(nodep->deleteTree(), nodep);
    }
    void replaceConcatMerge(AstConcat* nodep) {
+        // {llp OP lrp, rlp OP rrp} => {llp, rlp} OP {lrp, rrp}, where OP = AND/OR/XOR
        AstNodeBiop* const lp = VN_AS(nodep->lhsp(), NodeBiop);
        AstNodeBiop* const rp = VN_AS(nodep->rhsp(), NodeBiop);
        AstNodeExpr* const llp = lp->lhsp()->cloneTree(false);
@@ -2053,7 +2053,7 @@ private:
                VL_DO_DANGLING(nodep->unlinkFrBack()->deleteTree(), nodep);
                return true;
            }
-        } else if (m_doV && VN_IS(nodep->lhsp(), Concat)) {
+        } else if (m_doV && VN_IS(nodep->lhsp(), Concat) && nodep->isTreePureRecurse()) {
            bool need_temp = false;
            if (m_warn && !VN_IS(nodep, AssignDly)) {  // Is same var on LHS and RHS?
                // Note only do this (need user4) when m_warn, which is
@@ -2146,33 +2146,42 @@ private:
            return true;
        } else if (m_doV && VN_IS(nodep->rhsp(), StreamR)) {
            // The right-streaming operator on rhs of assignment does not
-            // change the order of bits. Eliminate stream but keep its lhsp
-            // Unlink the stuff
-            AstNodeExpr* const srcp = VN_AS(nodep->rhsp(), StreamR)->lhsp()->unlinkFrBack();
-            AstNode* const sizep = VN_AS(nodep->rhsp(), StreamR)->rhsp()->unlinkFrBack();
-            AstNodeExpr* const streamp = VN_AS(nodep->rhsp(), StreamR)->unlinkFrBack();
+            // change the order of bits. Eliminate stream but keep its lhsp.
+            // Add a cast if needed.
+            AstStreamR* const streamp = VN_AS(nodep->rhsp(), StreamR)->unlinkFrBack();
+            AstNodeExpr* srcp = streamp->lhsp()->unlinkFrBack();
+            AstNodeDType* const srcDTypep = srcp->dtypep();
+            if (VN_IS(srcDTypep, QueueDType) || VN_IS(srcDTypep, DynArrayDType)) {
+                if (nodep->lhsp()->widthMin() > 64) {
+                    nodep->v3warn(E_UNSUPPORTED, "Unsupported: Assignment of stream of dynamic "
+                                                 "array to a variable of size greater than 64");
+                }
+                srcp = new AstCvtDynArrayToPacked{srcp->fileline(), srcp, srcDTypep};
+            }
            nodep->rhsp(srcp);
-            // Cleanup
-            VL_DO_DANGLING(sizep->deleteTree(), sizep);
            VL_DO_DANGLING(streamp->deleteTree(), streamp);
            // Further reduce, any of the nodes may have more reductions.
            return true;
        } else if (m_doV && VN_IS(nodep->lhsp(), StreamL)) {
            // Push the stream operator to the rhs of the assignment statement
-            const int dWidth = VN_AS(nodep->lhsp(), StreamL)->lhsp()->width();
-            const int sWidth = nodep->rhsp()->width();
-            // Unlink the stuff
-            AstNodeExpr* const dstp = VN_AS(nodep->lhsp(), StreamL)->lhsp()->unlinkFrBack();
-            AstNodeExpr* streamp = VN_AS(nodep->lhsp(), StreamL)->unlinkFrBack();
+            AstNodeExpr* streamp = nodep->lhsp()->unlinkFrBack();
+            AstNodeExpr* const dstp = VN_AS(streamp, StreamL)->lhsp()->unlinkFrBack();
            AstNodeExpr* const srcp = nodep->rhsp()->unlinkFrBack();
+            const int sWidth = srcp->width();
+            const int dWidth = dstp->width();
            // Connect the rhs to the stream operator and update its width
            VN_AS(streamp, StreamL)->lhsp(srcp);
-            streamp->dtypeSetLogicUnsized(srcp->width(), srcp->widthMin(), VSigning::UNSIGNED);
-            // Shrink the RHS if necessary
-            if (sWidth > dWidth) {
+            if (VN_IS(srcp->dtypep(), DynArrayDType) || VN_IS(srcp->dtypep(), QueueDType)
+                || VN_IS(srcp->dtypep(), UnpackArrayDType)) {
+                streamp->dtypeSetStream();
+            } else {
+                streamp->dtypeSetLogicUnsized(srcp->width(), srcp->widthMin(), VSigning::UNSIGNED);
+            }
+            if (dWidth == 0) {
+                streamp = new AstCvtPackedToDynArray{nodep->fileline(), streamp, dstp->dtypep()};
+            } else if (sWidth > dWidth) {
                streamp = new AstSel{streamp->fileline(), streamp, sWidth - dWidth, dWidth};
            }
-            // Link the nodes back in
            nodep->lhsp(dstp);
            nodep->rhsp(streamp);
            return true;
@@ -2180,23 +2189,35 @@ private:
            // The right stream operator on lhs of assignment statement does
            // not reorder bits. However, if the rhs is wider than the lhs,
            // then we select bits from the left-most, not the right-most.
-            const int dWidth = VN_AS(nodep->lhsp(), StreamR)->lhsp()->width();
-            const int sWidth = nodep->rhsp()->width();
-            // Unlink the stuff
-            AstNodeExpr* const dstp = VN_AS(nodep->lhsp(), StreamR)->lhsp()->unlinkFrBack();
-            AstNode* const sizep = VN_AS(nodep->lhsp(), StreamR)->rhsp()->unlinkFrBack();
-            AstNodeExpr* const streamp = VN_AS(nodep->lhsp(), StreamR)->unlinkFrBack();
+            AstNodeExpr* const streamp = nodep->lhsp()->unlinkFrBack();
+            AstNodeExpr* const dstp = VN_AS(streamp, StreamR)->lhsp()->unlinkFrBack();
            AstNodeExpr* srcp = nodep->rhsp()->unlinkFrBack();
-            if (sWidth > dWidth) {
+            const int sWidth = srcp->width();
+            const int dWidth = dstp->width();
+            if (dWidth == 0) {
+                srcp = new AstCvtPackedToDynArray{nodep->fileline(), srcp, dstp->dtypep()};
+            } else if (sWidth > dWidth) {
                srcp = new AstSel{streamp->fileline(), srcp, sWidth - dWidth, dWidth};
            }
            nodep->lhsp(dstp);
            nodep->rhsp(srcp);
-            // Cleanup
-            VL_DO_DANGLING(sizep->deleteTree(), sizep);
            VL_DO_DANGLING(streamp->deleteTree(), streamp);
            // Further reduce, any of the nodes may have more reductions.
            return true;
+        } else if (m_doV && VN_IS(nodep->rhsp(), StreamL)) {
+            AstNodeDType* const lhsDtypep = nodep->lhsp()->dtypep();
+            AstStreamL* streamp = VN_AS(nodep->rhsp(), StreamL);
+            AstNodeExpr* const srcp = streamp->lhsp();
+            const AstNodeDType* const srcDTypep = srcp->dtypep();
+            if (VN_IS(srcDTypep, QueueDType) || VN_IS(srcDTypep, DynArrayDType)) {
+                if (lhsDtypep->widthMin() > 64) {
+                    nodep->v3warn(E_UNSUPPORTED, "Unsupported: Assignment of stream of dynamic "
+                                                 "array to a variable of size greater than 64");
+                }
+                srcp->unlinkFrBack();
+                streamp->lhsp(new AstCvtDynArrayToPacked{srcp->fileline(), srcp, lhsDtypep});
+                streamp->dtypeFrom(lhsDtypep);
+            }
        } else if (m_doV && replaceAssignMultiSel(nodep)) {
            return true;
        }
@@ -2265,7 +2286,7 @@ private:
    // VISITORS
    void visit(AstNetlist* nodep) override {
        // Iterate modules backwards, in bottom-up order.  That's faster
-        iterateChildrenBackwards(nodep);
+        iterateChildrenBackwardsConst(nodep);
    }
    void visit(AstNodeModule* nodep) override {
        VL_RESTORER(m_modp);
@@ -2284,6 +2305,13 @@ private:
            iterateChildren(nodep);
        }
    }
+    void visit(AstCLocalScope* nodep) override {
+        iterateChildren(nodep);
+        if (!nodep->stmtsp()) {
+            nodep->unlinkFrBack();
+            VL_DO_DANGLING(nodep->deleteTree(), nodep);
+        }
+    }
    void visit(AstScope* nodep) override {
        // No ASSIGNW removals under scope, we've long eliminated INITIALs
        VL_RESTORER(m_wremove);
@@ -2747,52 +2775,74 @@ private:
        }
    }

-    struct SenItemCmp {
-        bool operator()(const AstSenItem* lhsp, const AstSenItem* rhsp) const {
-            if (lhsp->type() < rhsp->type()) return true;
-            if (lhsp->type() > rhsp->type()) return false;
-            // Looks visually better if we keep sorted by name
-            if (!lhsp->sensp() && rhsp->sensp()) return true;
-            if (lhsp->sensp() && !rhsp->sensp()) return false;
-            if (lhsp->varrefp() && !rhsp->varrefp()) return true;
-            if (!lhsp->varrefp() && rhsp->varrefp()) return false;
-            if (lhsp->varrefp() && rhsp->varrefp()) {
-                if (lhsp->varrefp()->name() < rhsp->varrefp()->name()) return true;
-                if (lhsp->varrefp()->name() > rhsp->varrefp()->name()) return false;
+    class SenItemCmp final {
+        static int cmp(const AstNodeExpr* ap, const AstNodeExpr* bp) {
+            const VNType aType = ap->type();
+            const VNType bType = bp->type();
+            if (aType != bType) return static_cast<int>(bType) - static_cast<int>(aType);
+
+            if (const AstVarRef* const aRefp = VN_CAST(ap, VarRef)) {
+                const AstVarRef* const bRefp = VN_AS(bp, VarRef);
+                // Looks visually better if we keep sorted by name
+                if (aRefp->name() < bRefp->name()) return -1;
+                if (aRefp->name() > bRefp->name()) return 1;
                // But might be same name with different scopes
-                if (lhsp->varrefp()->varScopep() < rhsp->varrefp()->varScopep()) return true;
-                if (lhsp->varrefp()->varScopep() > rhsp->varrefp()->varScopep()) return false;
+                if (aRefp->varScopep() < bRefp->varScopep()) return -1;
+                if (aRefp->varScopep() > bRefp->varScopep()) return 1;
                // Or rarely, different data types
-                if (lhsp->varrefp()->dtypep() < rhsp->varrefp()->dtypep()) return true;
-                if (lhsp->varrefp()->dtypep() > rhsp->varrefp()->dtypep()) return false;
-            } else if (AstCMethodHard* const lp = VN_CAST(lhsp->sensp(), CMethodHard)) {
-                if (AstCMethodHard* const rp = VN_CAST(rhsp->sensp(), CMethodHard)) {
-                    if (AstVarRef* const lRefp = VN_CAST(lp->fromp(), VarRef)) {
-                        if (AstVarRef* const rRefp = VN_CAST(rp->fromp(), VarRef)) {
-                            if (lRefp->name() < rRefp->name()) return true;
-                            if (lRefp->name() > rRefp->name()) return false;
-                            // But might be same name with different scopes
-                            if (lRefp->varScopep() < rRefp->varScopep()) return true;
-                            if (lRefp->varScopep() > rRefp->varScopep()) return false;
-                            // Or rarely, different data types
-                            if (lRefp->dtypep() < rRefp->dtypep()) return true;
-                            if (lRefp->dtypep() > rRefp->dtypep()) return false;
-                        }
-                    }
-                    if (AstConst* lConstp = VN_CAST(lp->pinsp(), Const)) {
-                        if (AstConst* rConstp = VN_CAST(rp->pinsp(), Const)) {
-                            if (lConstp->toUInt() < rConstp->toUInt()) return true;
-                            if (lConstp->toUInt() > rConstp->toUInt()) return false;
-                        }
-                    }
-                }
+                if (aRefp->dtypep() < bRefp->dtypep()) return -1;
+                if (aRefp->dtypep() > bRefp->dtypep()) return 1;
+                return 0;
            }
-            // Sort by edge, AFTER variable, as we want multiple edges for same var adjacent.
-            // note the SenTree optimizer requires this order (more
-            // general first, less general last)
-            if (lhsp->edgeType() < rhsp->edgeType()) return true;
-            if (lhsp->edgeType() > rhsp->edgeType()) return false;
-            return false;
+
+            if (const AstConst* const aConstp = VN_CAST(ap, Const)) {
+                const AstConst* const bConstp = VN_AS(bp, Const);
+                if (aConstp->toUQuad() < bConstp->toUQuad()) return -1;
+                if (aConstp->toUQuad() > bConstp->toUQuad()) return 1;
+                return 0;
+            }
+
+            if (const AstNodeBiop* const aBiOpp = VN_CAST(ap, NodeBiop)) {
+                const AstNodeBiop* const bBiOpp = VN_AS(bp, NodeBiop);
+                // Compare RHSs first as LHS might be const, but the variable term should become
+                // adjacent for optimization if identical.
+                if (const int c = cmp(aBiOpp->rhsp(), bBiOpp->rhsp())) return c;
+                return cmp(aBiOpp->lhsp(), bBiOpp->lhsp());
+            }
+
+            if (const AstCMethodHard* const aCallp = VN_CAST(ap, CMethodHard)) {
+                const AstCMethodHard* const bCallp = VN_AS(bp, CMethodHard);
+                if (aCallp->name() < bCallp->name()) return -1;
+                if (aCallp->name() > bCallp->name()) return 1;
+                if (const int c = cmp(aCallp->fromp(), bCallp->fromp())) return c;
+                AstNodeExpr* aPinsp = aCallp->pinsp();
+                AstNodeExpr* bPinsp = bCallp->pinsp();
+                while (aPinsp && bPinsp) {
+                    if (const int c = cmp(aPinsp, bPinsp)) return c;
+                    aPinsp = VN_AS(aPinsp->nextp(), NodeExpr);
+                    bPinsp = VN_AS(bPinsp->nextp(), NodeExpr);
+                }
+                return aPinsp ? -1 : bPinsp ? 1 : 0;
+            }
+
+            return 0;
+        }
+
+    public:
+        bool operator()(const AstSenItem* lhsp, const AstSenItem* rhsp) const {
+            AstNodeExpr* const lSensp = lhsp->sensp();
+            AstNodeExpr* const rSensp = rhsp->sensp();
+            if (lSensp && rSensp) {
+                // If both terms have sensitivity expressions, recursively compare them
+                if (const int c = cmp(lSensp, rSensp)) return c < 0;
+            } else if (lSensp || rSensp) {
+                // Terms with sensitivity expressions come after those without
+                return rSensp;
+            }
+            // Finally sort by edge, AFTER variable, as we want multiple edges for same var
+            // adjacent. note the SenTree optimizer requires this order (more general first,
+            // less general last)
+            return lhsp->edgeType() < rhsp->edgeType();
        }
    };

@@ -2817,9 +2867,8 @@ private:
                }
            }

-            // Sort the sensitivity names so "posedge a or b" and "posedge b or a" end up together.
-            // Also, remove duplicate assignments, and fold POS&NEGs into ANYEDGEs
-            // Make things a little faster; check first if we need a sort
+            // Pass 1: Sort the sensitivity items so "posedge a or b" and "posedge b or a" and
+            // similar, optimizable expressions end up next to each other.
            for (AstSenItem *nextp, *senp = nodep->sensesp(); senp; senp = nextp) {
                nextp = VN_AS(senp->nextp(), SenItem);
                // cppcheck-suppress unassignedVariable  // cppcheck bug
@@ -2839,35 +2888,53 @@ private:
                }
            }

-            // Pass2, remove dup edges
-            for (AstSenItem *nextp, *senp = nodep->sensesp(); senp; senp = nextp) {
+            // Pass 2, remove duplicates and simplify adjacent terms if possible
+            for (AstSenItem *senp = nodep->sensesp(), *nextp; senp; senp = nextp) {
                nextp = VN_AS(senp->nextp(), SenItem);
-                AstSenItem* const litemp = senp;
-                AstSenItem* const ritemp = nextp;
-                if (ritemp) {
-                    if ((litemp->sensp() && ritemp->sensp()
-                         && litemp->sensp()->sameGateTree(ritemp->sensp()))
-                        || (!litemp->sensp() && !ritemp->sensp())) {
-                        // We've sorted in the order ANY, BOTH, POS, NEG,
-                        // so we don't need to try opposite orders
-                        if ((litemp->edgeType() == VEdgeType::ET_POSEDGE  // POS or NEG -> BOTH
-                             && ritemp->edgeType() == VEdgeType::ET_NEGEDGE)
-                            || (litemp->edgeType() == ritemp->edgeType())  // Identical edges
-                        ) {
-                            // Fix edge of old node
-                            if (litemp->edgeType() == VEdgeType::ET_POSEDGE
-                                && ritemp->edgeType() == VEdgeType::ET_NEGEDGE)
-                                litemp->edgeType(VEdgeType::ET_BOTHEDGE);
-                            // Remove redundant node
-                            VL_DO_DANGLING(ritemp->unlinkFrBack()->deleteTree(), ritemp);
-                            VL_DANGLING(ritemp);
-                            // Try to collapse again
-                            nextp = litemp;
+                if (!nextp) break;
+                AstSenItem* const lItemp = senp;
+                AstSenItem* const rItemp = nextp;
+                AstNodeExpr* const lSenp = lItemp->sensp();
+                AstNodeExpr* const rSenp = rItemp->sensp();
+                if (!lSenp || !rSenp) continue;
+
+                if (lSenp->sameGateTree(rSenp)) {
+                    // POSEDGE or NEGEDGE -> BOTHEDGE. (We've sorted POSEDGE, before NEGEDGE, so we
+                    // do not need to test for the opposite orders.)
+                    if (lItemp->edgeType() == VEdgeType::ET_POSEDGE
+                        && rItemp->edgeType() == VEdgeType::ET_NEGEDGE) {
+                        // Make both terms BOTHEDGE, the second will be removed below
+                        lItemp->edgeType(VEdgeType::ET_BOTHEDGE);
+                        rItemp->edgeType(VEdgeType::ET_BOTHEDGE);
+                    }
+
+                    // Remove identical expressions
+                    if (lItemp->edgeType() == rItemp->edgeType()) {
+                        VL_DO_DANGLING(rItemp->unlinkFrBack()->deleteTree(), rItemp);
+                        nextp = lItemp;
+                    }
+
+                    continue;
+                }
+
+                // Not identical terms, check if they can be combined
+                if (lSenp->width() != rSenp->width()) continue;
+                if (AstAnd* const lAndp = VN_CAST(lSenp, And)) {
+                    if (AstAnd* const rAndp = VN_CAST(rSenp, And)) {
+                        if (AstConst* const lConstp = VN_CAST(lAndp->lhsp(), Const)) {
+                            if (AstConst* const rConstp = VN_CAST(rAndp->lhsp(), Const)) {
+                                if (lAndp->rhsp()->sameTree(rAndp->rhsp())) {
+                                    const V3Number lNum{lConstp->num()};
+                                    lConstp->num().opOr(lNum, rConstp->num());
+                                    // Remove redundant term
+                                    VL_DO_DANGLING(rItemp->unlinkFrBack()->deleteTree(), rItemp);
+                                    nextp = lItemp;
+                                }
+                            }
                        }
                    }
                }
            }
-            // nodep->dumpTree("-  ssou: ");
        }
    }

@@ -2975,6 +3042,7 @@ private:
                AstNode* const thensp = nodep->thensp()->unlinkFrBackWithNext();
                AstNode* const elsesp = nodep->elsesp()->unlinkFrBackWithNext();
                AstIf* const ifp = new AstIf{nodep->fileline(), condp, elsesp, thensp};
+                ifp->isBoundsCheck(nodep->isBoundsCheck());  // Copy bounds check info
                ifp->branchPred(nodep->branchPred().invert());
                nodep->replaceWith(ifp);
                VL_DO_DANGLING(nodep->deleteTree(), nodep);
@@ -3025,7 +3093,7 @@ private:
                  && nodep->displayType() == VDisplayType::DT_WRITE)))
            return false;
        if ((prevp->filep() && !nodep->filep()) || (!prevp->filep() && nodep->filep())
-            || !prevp->filep()->sameTree(nodep->filep()))
+            || (prevp->filep() && nodep->filep() && !prevp->filep()->sameTree(nodep->filep())))
            return false;
        if (!prevp->fmtp() || prevp->fmtp()->nextp() || !nodep->fmtp() || nodep->fmtp()->nextp())
            return false;
@@ -3136,8 +3204,17 @@ private:
        iterateChildren(nodep);
    }

-    void visit(AstFuncRef* nodep) override {
+    void visit(AstNodeCCall* nodep) override {
        iterateChildren(nodep);
+        m_hasJumpDelay = true;  // As don't analyze inside tasks for timing controls
+    }
+    void visit(AstNodeFTaskRef* nodep) override {
+        // Note excludes AstFuncRef as other visitor below
+        iterateChildren(nodep);
+        m_hasJumpDelay = true;  // As don't analyze inside tasks for timing controls
+    }
+    void visit(AstFuncRef* nodep) override {
+        visit(static_cast<AstNodeFTaskRef*>(nodep));
        if (m_params) {  // Only parameters force us to do constant function call propagation
            replaceWithSimulation(nodep);
        }
@@ -3188,7 +3265,7 @@ private:

    void visit(AstStmtExpr* nodep) override {
        iterateChildren(nodep);
-        if (!nodep->exprp()) {
+        if (!nodep->exprp() || VN_IS(nodep->exprp(), Const)) {
            VL_DO_DANGLING(nodep->unlinkFrBack()->deleteTree(), nodep);
            return;
        }
@@ -3207,7 +3284,7 @@ private:

    void visit(AstJumpGo* nodep) override {
        iterateChildren(nodep);
-        // Jump to label where label immediately follows label is not useful
+        // Jump to label where label immediately follows this go is not useful
        if (nodep->labelp() == VN_CAST(nodep->nextp(), JumpLabel)) {
            VL_DO_DANGLING(nodep->unlinkFrBack()->deleteTree(), nodep);
            // Keep the label, might be other jumps pointing to it, gets cleaned later
@@ -3366,9 +3443,9 @@ private:
    TREEOPS("AstCond {$lhsp.isNeqZero}",        "replaceWIteratedRhs(nodep)");
    TREEOP ("AstCond{$condp.castNot,       $thenp, $elsep}", "AstCond{$condp->castNot()->lhsp(), $elsep, $thenp}");
    TREEOP ("AstNodeCond{$condp.width1, $thenp.width1,   $thenp.isAllOnes, $elsep}", "AstLogOr {$condp, $elsep}");  // a?1:b == a||b
-    TREEOP ("AstNodeCond{$condp.width1, $thenp.width1,   $thenp,    $elsep.isZero}", "AstLogAnd{$condp, $thenp}");  // a?b:0 == a&&b
+    TREEOP ("AstNodeCond{$condp.width1, $thenp.width1,   $thenp,    $elsep.isZero, !$elsep.isClassHandleValue}", "AstLogAnd{$condp, $thenp}");  // a?b:0 == a&&b
    TREEOP ("AstNodeCond{$condp.width1, $thenp.width1,   $thenp, $elsep.isAllOnes}", "AstLogOr {AstNot{$condp}, $thenp}");  // a?b:1 == ~a||b
-    TREEOP ("AstNodeCond{$condp.width1, $thenp.width1,   $thenp.isZero,    $elsep}", "AstLogAnd{AstNot{$condp}, $elsep}");  // a?0:b == ~a&&b
+    TREEOP ("AstNodeCond{$condp.width1, $thenp.width1,   $thenp.isZero, !$thenp.isClassHandleValue,   $elsep}", "AstLogAnd{AstNot{$condp}, $elsep}");  // a?0:b == ~a&&b
    TREEOP ("AstNodeCond{!$condp.width1, operandBoolShift(nodep->condp())}", "replaceBoolShift(nodep->condp())");
    // Prefer constants on left, since that often needs a shift, it lets
    // constant red remove the shift
@@ -3611,6 +3688,7 @@ private:
 public:
    // Processing Mode Enum
    enum ProcMode : uint8_t {
+        PROC_PARAMS_NOWARN,
        PROC_PARAMS,
        PROC_GENERATE,
        PROC_LIVE,
@@ -3626,16 +3704,18 @@ public:
        , m_concswapNames{globalPass ? ("__Vconcswap_" + cvtToStr(s_globalPassNum++)) : ""} {
        // clang-format off
        switch (pmode) {
-        case PROC_PARAMS:       m_doV = true;  m_doNConst = true; m_params = true;
-                                m_required = true; break;
-        case PROC_GENERATE:     m_doV = true;  m_doNConst = true; m_params = true;
-                                m_required = true; m_doGenerate = true; break;
-        case PROC_LIVE:         break;
-        case PROC_V_WARN:       m_doV = true;  m_doNConst = true; m_warn = true; break;
-        case PROC_V_NOWARN:     m_doV = true;  m_doNConst = true; break;
-        case PROC_V_EXPENSIVE:  m_doV = true;  m_doNConst = true; m_doExpensive = true; break;
-        case PROC_CPP:          m_doV = false; m_doNConst = true; m_doCpp = true; break;
-        default:                v3fatalSrc("Bad case"); break;
+        case PROC_PARAMS_NOWARN:  m_doV = true;  m_doNConst = true; m_params = true;
+                                  m_required = false; break;
+        case PROC_PARAMS:         m_doV = true;  m_doNConst = true; m_params = true;
+                                  m_required = true; break;
+        case PROC_GENERATE:       m_doV = true;  m_doNConst = true; m_params = true;
+                                  m_required = true; m_doGenerate = true; break;
+        case PROC_LIVE:           break;
+        case PROC_V_WARN:         m_doV = true;  m_doNConst = true; m_warn = true; break;
+        case PROC_V_NOWARN:       m_doV = true;  m_doNConst = true; break;
+        case PROC_V_EXPENSIVE:    m_doV = true;  m_doNConst = true; m_doExpensive = true; break;
+        case PROC_CPP:            m_doV = false; m_doNConst = true; m_doCpp = true; break;
+        default:                  v3fatalSrc("Bad case"); break;
        }
        // clang-format on
    }
@@ -3683,6 +3763,29 @@ AstNode* V3Const::constifyParamsEdit(AstNode* nodep) {
    return nodep;
 }

+//! Constify this cell node's parameter list if possible
+//! @return  Pointer to the edited node.
+AstNode* V3Const::constifyParamsNoWarnEdit(AstNode* nodep) {
+    // if (debug() > 0) nodep->dumpTree("-  forceConPRE : ");
+    // Resize even if the node already has a width, because buried in the tree
+    // we may have a node we just created with signing, etc, that isn't sized yet.
+
+    // Make sure we've sized everything first
+    nodep = V3Width::widthParamsEdit(nodep);
+    ConstVisitor visitor{ConstVisitor::PROC_PARAMS_NOWARN, /* globalPass: */ false};
+    if (AstVar* const varp = VN_CAST(nodep, Var)) {
+        // If a var wants to be constified, it's really a param, and
+        // we want the value to be constant.  We aren't passed just the
+        // init value because we need widthing above to handle the var's type.
+        if (varp->valuep()) visitor.mainAcceptEdit(varp->valuep());
+    } else {
+        nodep = visitor.mainAcceptEdit(nodep);
+    }
+    // Because we do edits, nodep links may get trashed and core dump this.
+    // if (debug() > 0) nodep->dumpTree("-  forceConDONE: ");
+    return nodep;
+}
+
 //! Force this cell node's parameter list to become a constant inside generate.
 //! If we are inside a generated "if", "case" or "for", we don't want to
 //! trigger warnings when we deal with the width. It is possible that these
@@ -3720,7 +3823,7 @@ void V3Const::constifyAllLint(AstNetlist* nodep) {
        ConstVisitor visitor{ConstVisitor::PROC_V_WARN, /* globalPass: */ true};
        (void)visitor.mainAcceptEdit(nodep);
    }  // Destruct before checking
-    V3Global::dumpCheckGlobalTree("const", 0, dumpTree() >= 3);
+    V3Global::dumpCheckGlobalTree("const", 0, dumpTreeLevel() >= 3);
 }

 void V3Const::constifyCpp(AstNetlist* nodep) {
@@ -3729,7 +3832,7 @@ void V3Const::constifyCpp(AstNetlist* nodep) {
        ConstVisitor visitor{ConstVisitor::PROC_CPP, /* globalPass: */ true};
        (void)visitor.mainAcceptEdit(nodep);
    }  // Destruct before checking
-    V3Global::dumpCheckGlobalTree("const_cpp", 0, dumpTree() >= 3);
+    V3Global::dumpCheckGlobalTree("const_cpp", 0, dumpTreeLevel() >= 3);
 }

 AstNode* V3Const::constifyEdit(AstNode* nodep) {
@@ -3753,7 +3856,7 @@ void V3Const::constifyAllLive(AstNetlist* nodep) {
        ConstVisitor visitor{ConstVisitor::PROC_LIVE, /* globalPass: */ true};
        (void)visitor.mainAcceptEdit(nodep);
    }  // Destruct before checking
-    V3Global::dumpCheckGlobalTree("const", 0, dumpTree() >= 3);
+    V3Global::dumpCheckGlobalTree("const", 0, dumpTreeLevel() >= 3);
 }

 void V3Const::constifyAll(AstNetlist* nodep) {
@@ -3763,7 +3866,7 @@ void V3Const::constifyAll(AstNetlist* nodep) {
        ConstVisitor visitor{ConstVisitor::PROC_V_EXPENSIVE, /* globalPass: */ true};
        (void)visitor.mainAcceptEdit(nodep);
    }  // Destruct before checking
-    V3Global::dumpCheckGlobalTree("const", 0, dumpTree() >= 3);
+    V3Global::dumpCheckGlobalTree("const", 0, dumpTreeLevel() >= 3);
 }

 AstNode* V3Const::constifyExpensiveEdit(AstNode* nodep) {
@@ -30,6 +30,10 @@ public:
    static AstNodeExpr* constifyParamsEdit(AstNodeExpr* exprp) {
        return VN_AS(constifyParamsEdit(static_cast<AstNode*>(exprp)), NodeExpr);
    }
+    static AstNode* constifyParamsNoWarnEdit(AstNode* nodep);
+    static AstNodeExpr* constifyParamsNoWarnEdit(AstNodeExpr* exprp) {
+        return VN_AS(constifyParamsNoWarnEdit(static_cast<AstNode*>(exprp)), NodeExpr);
+    }
    static AstNode* constifyGenerateParamsEdit(AstNode* nodep);
    // Only do constant pushing, without removing dead logic
    static void constifyAllLive(AstNetlist* nodep);
@@ -567,5 +567,5 @@ public:
 void V3Coverage::coverage(AstNetlist* rootp) {
    UINFO(2, __FUNCTION__ << ": " << endl);
    { CoverageVisitor{rootp}; }  // Destruct before checking
-    V3Global::dumpCheckGlobalTree("coverage", 0, dumpTree() >= 3);
+    V3Global::dumpCheckGlobalTree("coverage", 0, dumpTreeLevel() >= 3);
 }
@@ -117,5 +117,5 @@ public:
 void V3CoverageJoin::coverageJoin(AstNetlist* rootp) {
    UINFO(2, __FUNCTION__ << ": " << endl);
    { CoverageJoinVisitor{rootp}; }  // Destruct before checking
-    V3Global::dumpCheckGlobalTree("coveragejoin", 0, dumpTree() >= 3);
+    V3Global::dumpCheckGlobalTree("coveragejoin", 0, dumpTreeLevel() >= 3);
 }
@@ -62,9 +62,10 @@ private:
    // TYPES
    using AssignMap = std::multimap<AstVarScope*, AstNodeAssign*>;

-    // STATE
-    AstNodeModule* m_modp = nullptr;  // Current module
-    AstSelLoopVars* m_selloopvarsp = nullptr;  // Current loop vars
+    // STATE - across all visitors
+    const bool m_elimUserVars;  // Allow removal of user's vars
+    const bool m_elimDTypes;  // Allow removal of DTypes
+    const bool m_elimCells;  // Allow removal of Cells
    // List of all encountered to avoid another loop through tree
    std::vector<AstVar*> m_varsp;
    std::vector<AstNode*> m_dtypesp;
@@ -73,13 +74,14 @@ private:
    std::vector<AstCell*> m_cellsp;
    std::vector<AstClass*> m_classesp;
    std::vector<AstTypedef*> m_typedefsp;
-
    AssignMap m_assignMap;  // List of all simple assignments for each variable
-    const bool m_elimUserVars;  // Allow removal of user's vars
-    const bool m_elimDTypes;  // Allow removal of DTypes
-    const bool m_elimCells;  // Allow removal of Cells
    bool m_sideEffect = false;  // Side effects discovered in assign RHS

+    // STATE - for current visit position (use VL_RESTORER)
+    bool m_inAssign = false;  // Currently in an assign
+    AstNodeModule* m_modp = nullptr;  // Current module
+    AstSelLoopVars* m_selloopvarsp = nullptr;  // Current loop vars
+
    // METHODS

    void checkAll(AstNode* nodep) {
@@ -107,18 +109,16 @@ private:
    void visit(AstNodeModule* nodep) override {
        if (m_modp) m_modp->user1Inc();  // e.g. Class under Package
        VL_RESTORER(m_modp);
-        {
-            m_modp = nodep;
-            if (!nodep->dead()) {
-                iterateChildren(nodep);
-                checkAll(nodep);
-                if (AstClass* const classp = VN_CAST(nodep, Class)) {
-                    if (classp->extendsp()) classp->extendsp()->user1Inc();
-                    if (classp->classOrPackagep()) classp->classOrPackagep()->user1Inc();
-                    m_classesp.push_back(classp);
-                    // TODO we don't reclaim dead classes yet - graph implementation instead?
-                    classp->user1Inc();
-                }
+        m_modp = nodep;
+        if (!nodep->dead()) {
+            iterateChildren(nodep);
+            checkAll(nodep);
+            if (AstClass* const classp = VN_CAST(nodep, Class)) {
+                if (classp->extendsp()) classp->extendsp()->user1Inc();
+                if (classp->classOrPackagep()) classp->classOrPackagep()->user1Inc();
+                m_classesp.push_back(classp);
+                // TODO we don't reclaim dead classes yet - graph implementation instead?
+                classp->user1Inc();
            }
        }
    }
@@ -282,8 +282,11 @@ private:
        // See if simple assignments to variables may be eliminated because
        // that variable is never used.
        // Similar code in V3Life
-        VL_RESTORER(m_sideEffect);
+        const bool assignInAssign = m_inAssign;  // Might be Assign(..., ExprStmt(Assign), ...)
        {
+            VL_RESTORER(m_inAssign);
+            VL_RESTORER(m_sideEffect);
+            m_inAssign = true;
            m_sideEffect = false;
            iterateAndNextNull(nodep->rhsp());
            checkAll(nodep);
@@ -299,6 +302,7 @@ private:
            }
            iterateNull(nodep->timingControlp());
        }
+        if (assignInAssign) m_sideEffect = true;  // Parent assign shouldn't optimize
    }

    //-----
@@ -539,29 +543,29 @@ void V3Dead::deadifyModules(AstNetlist* nodep) {
    {
        DeadVisitor{nodep, false, false, false, false, !v3Global.opt.topIfacesSupported()};
    }  // Destruct before checking
-    V3Global::dumpCheckGlobalTree("deadModules", 0, dumpTree() >= 6);
+    V3Global::dumpCheckGlobalTree("deadModules", 0, dumpTreeLevel() >= 6);
 }

 void V3Dead::deadifyDTypes(AstNetlist* nodep) {
    UINFO(2, __FUNCTION__ << ": " << endl);
    { DeadVisitor{nodep, false, true, false, false, false}; }  // Destruct before checking
-    V3Global::dumpCheckGlobalTree("deadDtypes", 0, dumpTree() >= 3);
+    V3Global::dumpCheckGlobalTree("deadDtypes", 0, dumpTreeLevel() >= 3);
 }

 void V3Dead::deadifyDTypesScoped(AstNetlist* nodep) {
    UINFO(2, __FUNCTION__ << ": " << endl);
    { DeadVisitor{nodep, false, true, true, false, false}; }  // Destruct before checking
-    V3Global::dumpCheckGlobalTree("deadDtypesScoped", 0, dumpTree() >= 3);
+    V3Global::dumpCheckGlobalTree("deadDtypesScoped", 0, dumpTreeLevel() >= 3);
 }

 void V3Dead::deadifyAll(AstNetlist* nodep) {
    UINFO(2, __FUNCTION__ << ": " << endl);
    { DeadVisitor{nodep, true, true, false, true, false}; }  // Destruct before checking
-    V3Global::dumpCheckGlobalTree("deadAll", 0, dumpTree() >= 3);
+    V3Global::dumpCheckGlobalTree("deadAll", 0, dumpTreeLevel() >= 3);
 }

 void V3Dead::deadifyAllScoped(AstNetlist* nodep) {
    UINFO(2, __FUNCTION__ << ": " << endl);
    { DeadVisitor{nodep, true, true, true, true, false}; }  // Destruct before checking
-    V3Global::dumpCheckGlobalTree("deadAllScoped", 0, dumpTree() >= 3);
+    V3Global::dumpCheckGlobalTree("deadAllScoped", 0, dumpTreeLevel() >= 3);
 }
@@ -92,21 +92,23 @@ private:
    const VNUser4InUse m_inuser4;
    const VNUser5InUse m_inuser5;

-    // STATE
+    // STATE - across all visitors
+    std::unordered_map<const AstVarScope*, int> m_scopeVecMap;  // Next var number for each scope
+    std::set<AstSenTree*> m_timingDomains;  // Timing resume domains
+    using VarMap = std::map<const std::pair<AstNodeModule*, std::string>, AstVar*>;
+    VarMap m_modVarMap;  // Table of new var names created under module
+    VDouble0 m_statSharedSet;  // Statistic tracking
+
+    // STATE - for current visit position (use VL_RESTORER)
    AstActive* m_activep = nullptr;  // Current activate
    const AstCFunc* m_cfuncp = nullptr;  // Current public C Function
    AstAssignDly* m_nextDlyp = nullptr;  // Next delayed assignment in a list of assignments
    AstNodeProcedure* m_procp = nullptr;  // Current process
-    std::set<AstSenTree*> m_timingDomains;  // Timing resume domains
    bool m_inDly = false;  // True in delayed assignments
    bool m_inLoop = false;  // True in for loops
    bool m_inInitial = false;  // True in static initializers and initial blocks
    bool m_inSuspendableOrFork = false;  // True in suspendable processes and forks
    bool m_ignoreBlkAndNBlk = false;  // Suppress delayed assignment BLKANDNBLK
-    using VarMap = std::map<const std::pair<AstNodeModule*, std::string>, AstVar*>;
-    VarMap m_modVarMap;  // Table of new var names created under module
-    VDouble0 m_statSharedSet;  // Statistic tracking
-    std::unordered_map<const AstVarScope*, int> m_scopeVecMap;  // Next var number for each scope

    // METHODS

@@ -262,8 +264,8 @@ private:
            if (VN_IS(dimp, Const)) {  // bit = const, can just use it
                dimreadps.push_front(dimp);
            } else {
-                const string bitvarname = (string("__Vdlyvdim") + cvtToStr(dimension) + "__"
-                                           + oldvarp->shortName() + "__v" + cvtToStr(modVecNum));
+                const string bitvarname = string{"__Vdlyvdim"} + cvtToStr(dimension) + "__"
+                                          + oldvarp->shortName() + "__v" + cvtToStr(modVecNum);
                AstVarScope* const bitvscp
                    = createVarSc(varrefp->varScopep(), bitvarname, dimp->width(), nullptr);
                AstAssign* const bitassignp = new AstAssign{
@@ -282,8 +284,8 @@ private:
                // vlsb = constant, can just push constant into where we use it
                bitreadp = lsbvaluep;
            } else {
-                const string bitvarname = (string("__Vdlyvlsb__") + oldvarp->shortName() + "__v"
-                                           + cvtToStr(modVecNum));
+                const string bitvarname
+                    = string{"__Vdlyvlsb__"} + oldvarp->shortName() + "__v" + cvtToStr(modVecNum);
                AstVarScope* const bitvscp
                    = createVarSc(varrefp->varScopep(), bitvarname, lsbvaluep->width(), nullptr);
                AstAssign* const bitassignp = new AstAssign{
@@ -301,7 +303,7 @@ private:
            valreadp = nodep->rhsp()->unlinkFrBack();
        } else {
            const string valvarname
-                = (string("__Vdlyvval__") + oldvarp->shortName() + "__v" + cvtToStr(modVecNum));
+                = string{"__Vdlyvval__"} + oldvarp->shortName() + "__v" + cvtToStr(modVecNum);
            AstVarScope* const valvscp
                = createVarSc(varrefp->varScopep(), valvarname, 0, nodep->rhsp()->dtypep());
            newlhsp = new AstVarRef{nodep->fileline(), valvscp, VAccess::WRITE};
@@ -321,7 +323,7 @@ private:
            ++m_statSharedSet;
        } else {  // Create new one
            const string setvarname
-                = (string("__Vdlyvset__") + oldvarp->shortName() + "__v" + cvtToStr(modVecNum));
+                = string{"__Vdlyvset__"} + oldvarp->shortName() + "__v" + cvtToStr(modVecNum);
            setvscp = createVarSc(varrefp->varScopep(), setvarname, 1, nullptr);
            if (!m_inSuspendableOrFork) {
                // Suspendables reset __Vdlyvset__ in the AstAlwaysPost
@@ -424,10 +426,8 @@ private:
    }
    void visit(AstCFunc* nodep) override {
        VL_RESTORER(m_cfuncp);
-        {
-            m_cfuncp = nodep;
-            iterateChildren(nodep);
-        }
+        m_cfuncp = nodep;
+        iterateChildren(nodep);
    }
    void visit(AstActive* nodep) override {
        m_activep = nodep;
@@ -443,10 +443,12 @@ private:
    void visit(AstNodeProcedure* nodep) override {
        VL_RESTORER(m_inSuspendableOrFork);
        m_inSuspendableOrFork = nodep->isSuspendable();
-        m_procp = nodep;
-        m_timingDomains.clear();
-        iterateChildren(nodep);
-        m_procp = nullptr;
+        {
+            VL_RESTORER(m_procp);
+            m_procp = nodep;
+            m_timingDomains.clear();
+            iterateChildren(nodep);
+        }
        if (m_timingDomains.empty()) return;
        if (auto* const actp = VN_AS(nodep->user3p(), Active)) {
            // Merge all timing domains (and possibly the active's domain) to create a sentree for
@@ -474,14 +476,16 @@ private:
        m_inSuspendableOrFork = true;
        iterateChildren(nodep);
    }
-    void visit(AstCAwait* nodep) override { m_timingDomains.insert(nodep->sensesp()); }
+    void visit(AstCAwait* nodep) override {
+        if (nodep->sensesp()) m_timingDomains.insert(nodep->sensesp());
+    }
    void visit(AstFireEvent* nodep) override {
        UASSERT_OBJ(v3Global.hasEvents(), nodep, "Inconsistent");
        FileLine* const flp = nodep->fileline();
        if (nodep->isDelayed()) {
            AstVarRef* const vrefp = VN_AS(nodep->operandp(), VarRef);
            vrefp->unlinkFrBack();
-            const string newvarname = (string("__Vdly__") + vrefp->varp()->shortName());
+            const string newvarname = string{"__Vdly__"} + vrefp->varp()->shortName();
            AstVarScope* const dlyvscp = createVarSc(vrefp->varScopep(), newvarname, 1, nullptr);

            const auto dlyRef = [=](VAccess access) {
@@ -547,7 +551,9 @@ private:
            }
            if (!lhsp->backp()) VL_DO_DANGLING(pushDeletep(lhsp), lhsp);
        } else {
-            iterateChildren(nodep);
+            iterate(nodep->lhsp());
+            m_inDly = false;
+            iterate(nodep->rhsp());
        }
    }

@@ -570,7 +576,7 @@ private:
                    checkActivePost(nodep, oldactivep);
                }
                if (!dlyvscp) {  // First use of this delayed variable
-                    const string newvarname = (string("__Vdly__") + nodep->varp()->shortName());
+                    const string newvarname = string{"__Vdly__"} + nodep->varp()->shortName();
                    dlyvscp = createVarSc(oldvscp, newvarname, 0, nullptr);
                    AstNodeAssign* const prep = new AstAssignPre{
                        nodep->fileline(),
@@ -616,10 +622,14 @@ private:
    }
    void visit(AstWhile* nodep) override {
        VL_RESTORER(m_inLoop);
-        {
-            m_inLoop = true;
-            iterateChildren(nodep);
-        }
+        m_inLoop = true;
+        iterateChildren(nodep);
+    }
+    void visit(AstExprStmt* nodep) override {
+        VL_RESTORER(m_inDly);
+        // Restoring is needed, because AstExprStmt may contain assignments
+        m_inDly = false;
+        iterateChildren(nodep);
    }

    //--------------------
@@ -639,5 +649,5 @@ public:
 void V3Delayed::delayedAll(AstNetlist* nodep) {
    UINFO(2, __FUNCTION__ << ": " << endl);
    { DelayedVisitor{nodep}; }  // Destruct before checking
-    V3Global::dumpCheckGlobalTree("delayed", 0, dumpTree() >= 3);
+    V3Global::dumpCheckGlobalTree("delayed", 0, dumpTreeLevel() >= 3);
 }
@@ -166,5 +166,5 @@ public:
 void V3Depth::depthAll(AstNetlist* nodep) {
    UINFO(2, __FUNCTION__ << ": " << endl);
    { DepthVisitor{nodep}; }  // Destruct before checking
-    V3Global::dumpCheckGlobalTree("depth", 0, dumpTree() >= 6);
+    V3Global::dumpCheckGlobalTree("depth", 0, dumpTreeLevel() >= 6);
 }
@@ -63,7 +63,7 @@ private:
        AstCCall* const callp = new AstCCall{nodep->fileline(), funcp};
        callp->dtypeSetVoid();
        if (VN_IS(m_modp, Class)) {
-            funcp->argTypes(EmitCBaseVisitor::symClassVar());
+            funcp->argTypes(EmitCBase::symClassVar());
            callp->argTypes("vlSymsp");
        }
        UINFO(6, "      New " << callp << endl);
@@ -93,6 +93,7 @@ private:
        }
    }
    void visit(AstStmtExpr* nodep) override {}  // Stop recursion after introducing new function
+    void visit(AstJumpBlock*) override {}  // Stop recursion as can't break up across a jump
    void visit(AstNodeStmt* nodep) override {
        m_depth++;
        if (m_depth > v3Global.opt.compLimitBlocks()) {  // Already done
@@ -126,5 +127,5 @@ public:
 void V3DepthBlock::depthBlockAll(AstNetlist* nodep) {
    UINFO(2, __FUNCTION__ << ": " << endl);
    { DepthBlockVisitor{nodep}; }  // Destruct before checking
-    V3Global::dumpCheckGlobalTree("deepblock", 0, dumpTree() >= 3);
+    V3Global::dumpCheckGlobalTree("deepblock", 0, dumpTreeLevel() >= 3);
 }
@@ -46,6 +46,10 @@ private:

    // TYPES
    using FuncMmap = std::multimap<std::string, AstCFunc*>;
+    struct ScopeSelfPtr final {
+        VSelfPointerText thisPtr = VSelfPointerText{VSelfPointerText::Empty()};
+        VSelfPointerText vlSymsPtr = VSelfPointerText{VSelfPointerText::Empty()};
+    };

    // STATE
    AstNodeModule* m_modp = nullptr;  // Current module
@@ -53,6 +57,7 @@ private:
    const AstCFunc* m_funcp = nullptr;  // Current function
    bool m_modSingleton = false;  // m_modp is only instantiated once
    FuncMmap m_modFuncs;  // Name of public functions added
+    std::map<const AstScope*, ScopeSelfPtr> m_scopeToSelf;  // Scope to self pointers

    // METHODS

@@ -68,12 +73,32 @@ private:
        return (instances == 1);
    }

+    // Construct a 'this' self pointer for the given scope
+    VSelfPointerText scopeThis(const AstScope* scopep) {
+        auto& ret = m_scopeToSelf[scopep];
+        if (ret.thisPtr.isEmpty()) {
+            string name = scopep->name();
+            string::size_type pos;
+            if ((pos = name.rfind('.')) != string::npos) name.erase(0, pos + 1);
+            ret.thisPtr = VSelfPointerText{VSelfPointerText::This(), name};
+        }
+        return ret.thisPtr;
+    }
+    // Construct a 'vlSyms' self pointer for the given scope
+    VSelfPointerText scopeVlSyms(const AstScope* scopep) {
+        auto& ret = m_scopeToSelf[scopep];
+        if (ret.vlSymsPtr.isEmpty()) {
+            ret.vlSymsPtr = VSelfPointerText{VSelfPointerText::VlSyms(), scopep->nameDotless()};
+        }
+        return ret.vlSymsPtr;
+    }
+
    // Construct the best self pointer to reference an object in 'scopep'  from a CFunc in
    // 'm_scopep'. Result may be relative ("this->[...]") or absolute ("vlSyms->[...]").
    //
    // Using relative references allows V3Combine'ing code across multiple instances of the same
    // module.
-    string descopedSelfPointer(const AstScope* scopep) {
+    VSelfPointerText descopedSelfPointer(const AstScope* scopep) {
        UASSERT(scopep, "Var/Func not scoped");
        // Static functions can't use relative references via 'this->'
        const bool relativeRefOk = !m_funcp->isStatic();
@@ -85,23 +110,20 @@ private:
        if (VN_IS(scopep->modp(), Class)) {
            // Direct reference to class members are from within the class itself, references from
            // outside the class must go via AstMemberSel
-            return "this";
+            return VSelfPointerText{VSelfPointerText::This()};
        } else if (relativeRefOk && scopep == m_scopep) {
-            return "this";
+            return VSelfPointerText{VSelfPointerText::This()};
        } else if (relativeRefOk && !m_modSingleton && scopep->aboveScopep() == m_scopep
                   && VN_IS(scopep->modp(), Module)) {
            // Reference to scope of instance directly under this module, can just "this->cell",
            // which can potentially be V3Combined, but note this requires one extra pointer
            // dereference which is slower, so we only use it if the source scope is not a
            // singleton.
-            string name = scopep->name();
-            string::size_type pos;
-            if ((pos = name.rfind('.')) != string::npos) name.erase(0, pos + 1);
-            return "this->" + name;
+            return scopeThis(scopep);
        } else {
            // Reference to something elsewhere, or relative references are disabled. Use global
            // variable
-            return "(&" + scopep->nameVlSym() + ")";
+            return scopeVlSyms(scopep);
        }
    }

@@ -163,11 +185,10 @@ private:
                    if (moreOfSame) {
                        AstIf* const ifp = new AstIf{
                            funcp->fileline(),
-                            new AstEq{
-                                funcp->fileline(), new AstCExpr{funcp->fileline(), "this", 64},
-                                new AstCExpr{funcp->fileline(),
-                                             string("&(") + funcp->scopep()->nameVlSym() + ")",
-                                             64}},
+                            new AstEq{funcp->fileline(),
+                                      new AstCExpr{funcp->fileline(), "this", 64},
+                                      new AstCExpr{funcp->fileline(),
+                                                   scopeVlSyms(funcp->scopep()).asString(), 64}},
                            returnp};
                        newfuncp->addStmtsp(ifp);
                    } else {
@@ -178,7 +199,7 @@ private:
                // to come up with some return value
                // newfuncp->addStmtsp(new AstDisplay(newfuncp->fileline(),
                //                                   VDisplayType::DT_WARNING,
-                //                                   string("%%Error: ")+name+"() called with bad
+                //                                   string{"%%Error: "}+name+"() called with bad
                //                                   scope", nullptr));
                // newfuncp->addStmtsp(new AstStop(newfuncp->fileline()));
                if (debug() >= 9) newfuncp->dumpTree("-  newfunc: ");
@@ -225,15 +246,15 @@ private:
        const AstScope* const scopep = nodep->varScopep()->scopep();
        if (varp->isFuncLocal()) {
            // Reference to function locals need no self pointer
-            nodep->selfPointer("");
+            nodep->selfPointer(VSelfPointerText{VSelfPointerText::Empty()});
        } else if (scopep->modp() == v3Global.rootp()->constPoolp()->modp()) {
            // Reference to constant pool value need no self pointer
-            nodep->selfPointer("");
+            nodep->selfPointer(VSelfPointerText{VSelfPointerText::Empty()});
        } else {
            nodep->selfPointer(descopedSelfPointer(scopep));
        }
        nodep->varScopep(nullptr);
-        UINFO(9, "  refout " << nodep << " selfPtr=" << nodep->selfPointer() << endl);
+        UINFO(9, "  refout " << nodep << " selfPtr=" << nodep->selfPointer().asString() << endl);
    }
    void visit(AstCCall* nodep) override {
        // UINFO(9, "       " << nodep << endl);
@@ -285,5 +306,5 @@ public:
 void V3Descope::descopeAll(AstNetlist* nodep) {
    UINFO(2, __FUNCTION__ << ": " << endl);
    { DescopeVisitor{nodep}; }  // Destruct before checking
-    V3Global::dumpCheckGlobalTree("descope", 0, dumpTree() >= 3);
+    V3Global::dumpCheckGlobalTree("descope", 0, dumpTreeLevel() >= 3);
 }
@@ -503,11 +503,11 @@ public:
    inline bool inlined() const;

    // Methods that allow DfgVertex to participate in error reporting/messaging
-    void v3errorEnd(std::ostringstream& str) const VL_REQUIRES(V3Error::s().m_mutex) {
+    void v3errorEnd(std::ostringstream& str) const VL_RELEASE(V3Error::s().m_mutex) {
        m_filelinep->v3errorEnd(str);
    }
    void v3errorEndFatal(std::ostringstream& str) const VL_ATTR_NORETURN
-        VL_REQUIRES(V3Error::s().m_mutex) {
+        VL_RELEASE(V3Error::s().m_mutex) {
        m_filelinep->v3errorEndFatal(str);
    }
    string warnContextPrimary() const VL_REQUIRES(V3Error::s().m_mutex) {
@@ -334,17 +334,20 @@ class AstToDfgVisitor final : public VNVisitor {
                    const uint32_t bEnd = b.m_lsb + bWidth;
                    const uint32_t overlapEnd = std::min(aEnd, bEnd) - 1;

-                    varp->varp()->v3warn(  //
-                        MULTIDRIVEN,
-                        "Bits ["  //
-                            << overlapEnd << ":" << b.m_lsb << "] of signal "
-                            << varp->varp()->prettyNameQ()
-                            << " have multiple combinational drivers\n"
-                            << a.m_fileline->warnOther() << "... Location of first driver\n"
-                            << a.m_fileline->warnContextPrimary() << '\n'
-                            << b.m_fileline->warnOther() << "... Location of other driver\n"
-                            << b.m_fileline->warnContextSecondary() << varp->varp()->warnOther()
-                            << "... Only the first driver will be respected");
+                    if (a.m_fileline->operatorCompare(*b.m_fileline) != 0) {
+                        varp->varp()->v3warn(  //
+                            MULTIDRIVEN,
+                            "Bits ["  //
+                                << overlapEnd << ":" << b.m_lsb << "] of signal "
+                                << varp->varp()->prettyNameQ()
+                                << " have multiple combinational drivers\n"
+                                << a.m_fileline->warnOther() << "... Location of first driver\n"
+                                << a.m_fileline->warnContextPrimary() << '\n'
+                                << b.m_fileline->warnOther() << "... Location of other driver\n"
+                                << b.m_fileline->warnContextSecondary()
+                                << varp->varp()->warnOther()
+                                << "... Only the first driver will be respected");
+                    }

                    // If the first driver completely covers the range of the second driver,
                    // we can just delete the second driver completely, otherwise adjust the
@@ -437,6 +440,7 @@ class AstToDfgVisitor final : public VNVisitor {
    void visit(AstCell* nodep) override { markReferenced(nodep); }
    void visit(AstNodeProcedure* nodep) override { markReferenced(nodep); }
    void visit(AstVar* nodep) override {
+        if (nodep->isSc()) return;
        // No need to (and in fact cannot) handle variables with unsupported dtypes
        if (!DfgVertex::isSupportedDType(nodep->dtypep())) return;
        // Mark ports as having external references
@@ -59,8 +59,7 @@ AstCountOnes* makeNode<AstCountOnes, DfgCountOnes, AstNodeExpr*>(  //
    const DfgCountOnes* vtxp, AstNodeExpr* op1) {
    AstCountOnes* const nodep = new AstCountOnes{vtxp->fileline(), op1};
    // Set dtype same as V3Width
-    const int selwidth = V3Number::log2b(nodep->lhsp()->width()) + 1;
-    nodep->dtypeSetLogicSized(selwidth, VSigning::UNSIGNED);
+    nodep->dtypeSetLogicSized(32, VSigning::UNSIGNED);
    return nodep;
 }

@@ -237,7 +237,7 @@ void V3DfgOptimizer::extract(AstNetlist* netlistp) {
    UINFO(2, __FUNCTION__ << ": " << endl);
    // Extract more optimization candidates
    DataflowExtractVisitor::apply(netlistp);
-    V3Global::dumpCheckGlobalTree("dfg-extract", 0, dumpTree() >= 3);
+    V3Global::dumpCheckGlobalTree("dfg-extract", 0, dumpTreeLevel() >= 3);
 }

 void V3DfgOptimizer::optimize(AstNetlist* netlistp, const string& label) {
@@ -267,7 +267,7 @@ void V3DfgOptimizer::optimize(AstNetlist* netlistp, const string& label) {

        // Build the DFG of this module
        const std::unique_ptr<DfgGraph> dfg{V3DfgPasses::astToDfg(*modp, ctx)};
-        if (dumpDfg() >= 8) dfg->dumpDotFilePrefixed(ctx.prefix() + "whole-input");
+        if (dumpDfgLevel() >= 8) dfg->dumpDotFilePrefixed(ctx.prefix() + "whole-input");

        // Extract the cyclic sub-graphs. We do this because a lot of the optimizations assume a
        // DAG, and large, mostly acyclic graphs could not be optimized due to the presence of
@@ -284,7 +284,7 @@ void V3DfgOptimizer::optimize(AstNetlist* netlistp, const string& label) {

        // For each cyclic component
        for (auto& component : cyclicComponents) {
-            if (dumpDfg() >= 7) component->dumpDotFilePrefixed(ctx.prefix() + "source");
+            if (dumpDfgLevel() >= 7) component->dumpDotFilePrefixed(ctx.prefix() + "source");
            // TODO: Apply optimizations safe for cyclic graphs
            // Add back under the main DFG (we will convert everything back in one go)
            dfg->addGraph(*component);
@@ -292,7 +292,7 @@ void V3DfgOptimizer::optimize(AstNetlist* netlistp, const string& label) {

        // For each acyclic component
        for (auto& component : acyclicComponents) {
-            if (dumpDfg() >= 7) component->dumpDotFilePrefixed(ctx.prefix() + "source");
+            if (dumpDfgLevel() >= 7) component->dumpDotFilePrefixed(ctx.prefix() + "source");
            // Optimize the component
            V3DfgPasses::optimize(*component, ctx);
            // Add back under the main DFG (we will convert everything back in one go)
@@ -300,9 +300,9 @@ void V3DfgOptimizer::optimize(AstNetlist* netlistp, const string& label) {
        }

        // Convert back to Ast
-        if (dumpDfg() >= 8) dfg->dumpDotFilePrefixed(ctx.prefix() + "whole-optimized");
+        if (dumpDfgLevel() >= 8) dfg->dumpDotFilePrefixed(ctx.prefix() + "whole-optimized");
        AstModule* const resultModp = V3DfgPasses::dfgToAst(*dfg, ctx);
        UASSERT_OBJ(resultModp == modp, modp, "Should be the same module");
    }
-    V3Global::dumpCheckGlobalTree("dfg-optimize", 0, dumpTree() >= 3);
+    V3Global::dumpCheckGlobalTree("dfg-optimize", 0, dumpTreeLevel() >= 3);
 }
@@ -285,7 +285,7 @@ void V3DfgPasses::optimize(DfgGraph& dfg, V3DfgOptimizationContext& ctx) {

    const auto apply = [&](int dumpLevel, const string& name, std::function<void()> pass) {
        pass();
-        if (dumpDfg() >= dumpLevel) {
+        if (dumpDfgLevel() >= dumpLevel) {
            const string strippedName = VString::removeWhitespace(name);
            const string label
                = ctx.prefix() + "pass-" + cvtToStr(passNumber) + "-" + strippedName;
@@ -294,7 +294,7 @@ void V3DfgPasses::optimize(DfgGraph& dfg, V3DfgOptimizationContext& ctx) {
        ++passNumber;
    };

-    if (dumpDfg() >= 8) dfg.dumpDotAllVarConesPrefixed(ctx.prefix() + "input");
+    if (dumpDfgLevel() >= 8) dfg.dumpDotAllVarConesPrefixed(ctx.prefix() + "input");
    apply(3, "input           ", [&]() {});
    apply(4, "inlineVars      ", [&]() { inlineVars(dfg); });
    apply(4, "cse0            ", [&]() { cse(dfg, ctx.m_cseContext0); });
@@ -304,5 +304,5 @@ void V3DfgPasses::optimize(DfgGraph& dfg, V3DfgOptimizationContext& ctx) {
        apply(4, "cse1            ", [&]() { cse(dfg, ctx.m_cseContext1); });
    }
    apply(4, "removeVars      ", [&]() { removeVars(dfg, ctx.m_removeVarsContext); });
-    if (dumpDfg() >= 8) dfg.dumpDotAllVarConesPrefixed(ctx.prefix() + "optimized");
+    if (dumpDfgLevel() >= 8) dfg.dumpDotAllVarConesPrefixed(ctx.prefix() + "optimized");
 }
@@ -123,9 +123,9 @@ struct V3DfgPeepholeContext final {
    const std::string m_label;  // Label to apply to stats

    // Enable flags for each optimization
-    bool m_enabled[VDfgPeepholePattern::_ENUM_END];
+    std::array<bool, VDfgPeepholePattern::_ENUM_END> m_enabled;
    // Count of applications for each optimization (for statistics)
-    VDouble0 m_count[VDfgPeepholePattern::_ENUM_END];
+    std::array<VDouble0, VDfgPeepholePattern::_ENUM_END> m_count;

    explicit V3DfgPeepholeContext(const std::string& label);
    ~V3DfgPeepholeContext();
@@ -100,5 +100,5 @@ void V3DupFinder::dumpFile(const string& filename, bool tree) {
 }

 void V3DupFinder::dumpFilePrefixed(const string& nameComment, bool tree) {
-    if (dump()) dumpFile(v3Global.debugFilename(nameComment) + ".hash", tree);
+    if (dumpLevel()) dumpFile(v3Global.debugFilename(nameComment) + ".hash", tree);
 }
@@ -39,7 +39,7 @@ EmitCParentModule::EmitCParentModule() {
 //######################################################################
 // EmitCBaseVisitor implementation

-string EmitCBaseVisitor::funcNameProtect(const AstCFunc* nodep, const AstNodeModule* modp) {
+string EmitCBaseVisitorConst::funcNameProtect(const AstCFunc* nodep, const AstNodeModule* modp) {
    modp = modp ? modp : EmitCParentModule::get(nodep);
    string name;
    if (nodep->isConstructor()) {
@@ -57,15 +57,21 @@ string EmitCBaseVisitor::funcNameProtect(const AstCFunc* nodep, const AstNodeMod
    return name;
 }

-AstCFile* EmitCBaseVisitor::newCFile(const string& filename, bool slow, bool source, bool add) {
-    AstCFile* const cfilep = new AstCFile{v3Global.rootp()->fileline(), filename};
-    cfilep->slow(slow);
-    cfilep->source(source);
-    if (add) v3Global.rootp()->addFilesp(cfilep);
+AstCFile* EmitCBaseVisitorConst::newCFile(const string& filename, bool slow, bool source) {
+    AstCFile* const cfilep = createCFile(filename, slow, source);
+    v3Global.rootp()->addFilesp(cfilep);
    return cfilep;
 }

-string EmitCBaseVisitor::cFuncArgs(const AstCFunc* nodep) {
+AstCFile* EmitCBaseVisitorConst::createCFile(const string& filename, bool slow,
+                                             bool source) VL_MT_SAFE {
+    AstCFile* const cfilep = new AstCFile{v3Global.rootp()->fileline(), filename};
+    cfilep->slow(slow);
+    cfilep->source(source);
+    return cfilep;
+}
+
+string EmitCBaseVisitorConst::cFuncArgs(const AstCFunc* nodep) {
    // Return argument list for given C function
    string args;
    if (nodep->isLoose() && !nodep->isStatic()) {
@@ -73,6 +79,10 @@ string EmitCBaseVisitor::cFuncArgs(const AstCFunc* nodep) {
        args += prefixNameProtect(EmitCParentModule::get(nodep));
        args += "* vlSelf";
    }
+    if (nodep->needProcess()) {
+        if (!args.empty()) args += ", ";
+        args += "VlProcessRef vlProcess";
+    }
    if (!nodep->argTypes().empty()) {
        if (!args.empty()) args += ", ";
        args += nodep->argTypes();
@@ -95,8 +105,8 @@ string EmitCBaseVisitor::cFuncArgs(const AstCFunc* nodep) {
    return args;
 }

-void EmitCBaseVisitor::emitCFuncHeader(const AstCFunc* funcp, const AstNodeModule* modp,
-                                       bool withScope) {
+void EmitCBaseVisitorConst::emitCFuncHeader(const AstCFunc* funcp, const AstNodeModule* modp,
+                                            bool withScope) {
    if (funcp->slow()) puts("VL_ATTR_COLD ");
    if (!funcp->isConstructor() && !funcp->isDestructor()) {
        puts(funcp->rtnTypeVoid());
@@ -114,8 +124,8 @@ void EmitCBaseVisitor::emitCFuncHeader(const AstCFunc* funcp, const AstNodeModul
    if (funcp->isConst().trueKnown() && funcp->isProperMethod()) puts(" const");
 }

-void EmitCBaseVisitor::emitCFuncDecl(const AstCFunc* funcp, const AstNodeModule* modp,
-                                     bool cLinkage) {
+void EmitCBaseVisitorConst::emitCFuncDecl(const AstCFunc* funcp, const AstNodeModule* modp,
+                                          bool cLinkage) {
    ensureNewLine();
    if (!funcp->ifdef().empty()) puts("#ifdef " + funcp->ifdef() + "\n");
    if (cLinkage) puts("extern \"C\" ");
@@ -129,7 +139,7 @@ void EmitCBaseVisitor::emitCFuncDecl(const AstCFunc* funcp, const AstNodeModule*
    if (!funcp->ifdef().empty()) puts("#endif  // " + funcp->ifdef() + "\n");
 }

-void EmitCBaseVisitor::emitVarDecl(const AstVar* nodep, bool asRef) {
+void EmitCBaseVisitorConst::emitVarDecl(const AstVar* nodep, bool asRef) {
    const AstBasicDType* const basicp = nodep->basicp();
    bool refNeedParens = VN_IS(nodep->dtypeSkipRefp(), UnpackArrayDType);

@@ -217,25 +227,16 @@ void EmitCBaseVisitor::emitVarDecl(const AstVar* nodep, bool asRef) {
    }
 }

-void EmitCBaseVisitor::emitModCUse(const AstNodeModule* modp, VUseType useType) {
-    string nl;
-    for (AstNode* itemp = modp->stmtsp(); itemp; itemp = itemp->nextp()) {
-        if (AstCUse* const usep = VN_CAST(itemp, CUse)) {
-            if (usep->useType() == useType) {
-                if (usep->useType().isInclude()) {
-                    puts("#include \"" + prefixNameProtect(usep) + ".h\"\n");
-                }
-                if (usep->useType().isFwdClass()) {
-                    puts("class " + prefixNameProtect(usep) + ";\n");
-                }
-                nl = "\n";
-            }
-        }
-    }
-    puts(nl);
+void EmitCBaseVisitorConst::emitModCUse(const AstNodeModule* modp, VUseType useType) {
+    bool nl = false;
+    forModCUse(modp, useType, [&](string entry) {
+        puts(entry);
+        nl = true;
+    });
+    if (nl) puts("\n");
 }

-void EmitCBaseVisitor::emitTextSection(const AstNodeModule* modp, VNType type) {
+void EmitCBaseVisitorConst::emitTextSection(const AstNodeModule* modp, VNType type) {
    // Short circuit if nothing to do. This can save a lot of time on large designs as this
    // function needs to traverse the entire module linearly.
    if (!v3Global.hasSCTextSections()) return;
--- a/Show More
+++ b/Show More