Version bump

Fix some clang-analyzer warnings
examples: Fix wide signal overflow, and stop on errors.
2026-10-02 16:13:34 +02:00 · 2017-11-25 15:42:11 -05:00 · 2017-11-25 15:41:49 -05:00 · 2017-11-25 15:14:31 -05:00 · 2017-11-23 14:55:32 -05:00 · 2017-11-23 11:38:09 -05:00
779 changed files with 24711 additions and 9350 deletions
@@ -1,3 +1,5 @@
+\#*
+.#*
 *~
 *.old
 *.gz
@@ -20,8 +22,10 @@ configure
 dddrun*
 doxygen-doc
 gdbrun*
+gmon.out
 internals.txt
 verilator.txt
 verilator_bin*
 verilator_coverage_bin*
 verilator.pc
+**/obj_dir/*
@@ -1,7 +1,341 @@
 Revision history for Verilator

-The contributors that suggested a given feature are shown in [].  [by ...]
-indicates the contributor was also the author of the fix; Thanks!
+The contributors that suggested a given feature are shown in []. Thanks!
+
+* Verilator 3.916 2017-11-25
+
+***   Support self-recursive modules, bug659. [Sean Moore, et al]
+
+***   Support $error/$warning in elaboration time blocks.
+
+***   Support $size/$bits/etc on type references.
+
+***   Add error when driving input-only modport, bug1110. [Trevor Elbourne]
+
+***   Add BSSPACE and COLONPLUS lint warnings.
+
+****  Detect MSB overflow when under VL_DEBUG, bug1238. [Junyi Xi]
+
+****  Add data types to --xml. [Rui Terra]
+
+****  Fix partial slicing with pattern assignments, bug991. [Johan Bjork]
+
+****  Fix false unused warning on interfaces, bug1241. [Laurens van Dam]
+
+****  Fix error on "unique case" with no cases.
+
+****  Fix MacOS portability, bug1232. [Jeff Bush]
+
+
+* Verilator 3.914 2017-10-14
+
+**    Added new examples/ directory with appropriate examples. This replaces the
+      old test_c and test_sc directories.
+
+***   Add --getenv option for simplifying Makefiles.
+
+***   Add --x-initial option for specifying initial value assignment behavior.
+
+***   Add --no-relative-cfuncs and related default optimization, bug1224. [John Coiner]
+
+***   Add /*verilator tag*/ for XML extraction applications. [Chris Randall]
+
+****  The internal test_verilated test directory is moved to be part of test_regress.
+
+****  The experimental VL_THREADED setting (only, not normal mode) now requires C++11.
+
+****  Fix over-aggressive inlining, bug1223. [John Coiner]
+
+****  Fix Ubuntu 17.10 issues, bug1223 partial. [John Coiner]
+
+****  Fix compiler warning when WIDTH warning ignored on large compare.
+
+****  Fix memory leak in VerilatedVcd dumps, bug1222 partial. [Shareef Jalloq]
+
+****  Fix unnecessary Vdly variables, bug1224 partial. [John Coiner]
+
+****  Fix conditional slices and add related optimizations.
+
+****  Fix `` expansion of `defines, bug1225, bug1227, bug1228. [Odd Magne Reitan]
+
+****  Fix -E duplicating output, bug1226. [Odd Magne Reitan]
+
+****  Fix float-conversion warning, bug1229. [Robert Henry]
+
+****  Fix MacOS portability, bug1230, bug1231. [Jeff Bush]
+
+
+* Verilator 3.912 2017-09-23
+
+**    Verilated headers no longer "use namespace std;"
+      User's code without "std::" prefixes may need "use namespace std;" to compile.
+
+***   Support or/and/xor array intrinsic methods, bug1210. [Mike Popoloski]
+
+***   Support package export, bug1217. [Usuario Eda]
+
+***   Fix ordering of arrayed cell wide connections, bug1202 partial. [Mike Popoloski]
+
+****  Support module port parameters without defaults, bug 1213. [Mike Popoloski]
+
+****  Add performance information to --stats file.
+
+****  Simplify VL_CONST_W macro generation for faster compiles.
+
+****  Fix LITENDIAN warning on arrayed cells, bug1202. [Mike Popoloski]
+
+****  Fix enum ranges without colons, bug1204. [Mike Popoloski]
+
+****  Fix GCC noreturn compile error, bug1209. [Mike Popoloski]
+
+****  Fix constant function default parameters, bug1211. [Mike Popoloski]
+
+****  Fix non-colon array of interface modports, bug1212. [Mike Popoloski]
+
+****  Fix .name connections on interfaces, bug1214. [Mike Popoloski]
+
+****  Fix wide array indices causing compile error.
+
+****  Better optimize Shift-And, and replication constructs.
+
+
+* Verilator 3.910 2017-09-07
+
+***   SystemPerl mode (-sp-deprecated) has been removed.
+
+****  Update keyword warnings to include C++11 and others.
+
+
+* Verilator 3.908 2017-08-28
+
+****  Support x in $readmem, bug1180. [Arthur Kahlich]
+
+****  Support packed struct DPI imports, bug1190. [Rob Stoddard]
+
+****  Fix GCC 6 warnings.
+
+****  Fix compile error on unused VL_VALUEPLUSARGS_IW, bug1181. [Thomas J Whatson]
+
+****  Fix undefined VL_POW_WWI. [Clifford Wolf]
+
+****  Fix internal error on unconnected inouts, bug1187. [Rob Stoddard]
+
+
+* Verilator 3.906 2017-06-22
+
+***   Support set_time_unit/set_time_precision in C traces, msg2261.
+
+***   Fix extract of packed array with non-zero LSB, bug1172. [James Pallister]
+
+***   Fix shifts by more than 32-bit numbers, bug1174. [Clifford Wolf]
+
+***   Fix power operator on wide constants, bug761. [Clifford Wolf]
+
+***   Fix .* on interface pins, bug1176. [Maciej Piechotka]
+
+
+* Verilator 3.904 2017-05-30
+
+***   Fix non-cutable ordering loops on clock arrays, bug1009. [Todd Strader]
+
+***   Support ports of array of reals, bug1154. [J Briquet]
+
+***   Support arrayed parameter overrides, bug1153. [John Stevenson]
+
+***   Support $value$plusargs with variables, bug1165. [Wesley Terpstra]
+
+****  Support modport access to un-modport objects, bug1161. [Todd Strader]
+
+****  Add stack trace when can't optimize function, bug1158. [Todd Strader]
+
+****  Add warning on mis-sized literal, bug1156. [Todd Strader]
+
+****  Fix interface functions returning wrong parameters, bug996. [Todd Strader]
+
+****  Fix non-arrayed cells with interface arrays, bug1153. [John Stevenson]
+
+****  Fix --assert with complex case statements, bug1164. [Enzo Chi]
+
+
+* Verilator 3.902 2017-04-02
+
+**    Add -FI option to force includes,msg2146. [Amir Gonnen]
+
+**    Add --relative-includes. [Rob Stoddard]
+
+***   Add error on duplicate pattern assignments, bug1145. [Johan Bjork]
+
+****  Fix error on improperly widthed default function, bug984. [Todd Strader]
+
+****  Fix 2009 localparam syntax, msg2139. [Galen Seitz]
+
+****  Fix ugly interface-to-non-interface errors, bug1112. [Johan Bjork]
+
+****  Fix LDFLAGS and CFLAGS not preserving order, bug1130. [Olof Kindgren]
+
+****  Fix internal error on initializing parameter array, bug1131. [Jie Xu]
+
+****  Fix internal error on interface arrays, bug1135. [John Stevenson]
+
+****  Fix calling sformatf to display, and elab $displays, bug1139. [Johan Bjork]
+
+****  Fix realpath compile issue on MSVC++, bug1141. [Miodrag Milanovic]
+
+****  Fix missing error on interface size mismatch, bug1143.  [Johan Bjork]
+
+****  Fix error on parameters with dotted references, bug1146. [Johan Bjork]
+
+****  Fix wreal not handling continuous assign, bug1150. [J Briquet]
+
+****  Fix nested structure parameter selects, bug1150. [J Briquet]
+
+
+* Verilator 3.900 2017-01-15
+
+**    Internal code changes for improved compatibility and performance.
+
+***   Support old-style $display($time), bug467. [John Demme]
+
+****  With --bbox-unsup, suppress desassign and mixed edges, bug1120. [Galen Seitz]
+
+****  Fix parsing sensitivity with &&, bug934. [Luke Yang]
+
+****  Fix internal error on double-for loop unrolling, bug1044. [Jan Egil Ruud]
+
+****  Fix internal error on unique casez with --assert, bug1117. [Enzo Chi]
+
+****  Fix bad code when tracing array of structs, bug1122. [Andrew Bardsley]
+
+
+* Verilator 3.890 2016-11-25
+
+***   Honor --output-split on coverage constructors, bug1098. [Johan Bjork]
+
+****  Fix various issues when making outside of the kit.
+
+****  Fix flex 2.6.2 bug, bug1103. [Sergey Kvachonok]
+
+****  Fix error on bad interface name, bug1097. [Todd Strader]
+
+****  Fix error on referencing variable in parent, bug1099. [Ian Thompson]
+
+****  Fix type parameters with low optimization, bug1101. [Stefan Wallentowitz]
+
+
+* Verilator 3.888 2016-10-14
+
+**    Support foreach, bug1078. [Xuan Guo]
+
+***   Add --no-decoration to remove output comments, msg2015. [Frederic Requin]
+
+***   If VM_PARALLEL_BUILDS=1, use OPT_FAST and OPT_SLOW. [Frederic Requin]
+      Set VM_DEFAULT_RULES=0 for old behavior.
+
+****  Add error on DPI functions > 32 bits, msg1995. [Elliot Mednick]
+
+****  Fix SystemC compiles with VPI, bug1081. [Arthur Kahlich]
+
+****  Fix error on wide numbers that represent shifts, msg1991, bug1088. [Mandy Xu]
+
+****  Improve Verilation performance on internal strings, msg1975. [Johan Bjork]
+
+****  Improve Verilation performance on trace duplicates, bug1090. [Johan Bjork]
+
+
+* Verilator 3.886 2016-07-30
+
+****  Fix enum values of 11-16 bits wide using .next/.prev, bug1062. [Brian Flachs]
+
+****  Fix false warnings on non-power-2 enums using .next/.prev.
+
+****  Fix comparison of unpacked arrays, bug1071. [Andrew Bardsley]
+
+****  Fix compiler warning in GCC 6. [David Horton]
+
+
+* Verilator 3.884 2016-05-18
+
+**    Support parameter type, bug376. [Alan Hunter, et al]
+
+**    Support command-line -G/+pvalue param overrides, bug1045. [Stefan Wallentowitz]
+
+***   The default l2 scope name is now the same as the top-level module, bug1050.
+      Use "--l2-name v" for the historical behavior.
+
+***   Add --l2-name option for controlling "v" naming.
+
+****  Fix --output-split of constructors, bug1035. [Johan Bjork]
+
+****  Fix removal of empty packages, modules and cells, bug1034. [Johan Bjork]
+
+****  Fix core dump on Arch Linux/GCC 6.1.1, bug1058. [Jannis Harder]
+
+****  Fix $value$plusargs to string, msg1890. [Frederic Requin]
+
+
+* Verilator 3.882 2016-03-01
+
+****  Internal Verilation-time performance enhancements, bug1021. [Johan Bjork]
+
+****  Support inlining interfaces, bug1018. [Johan Bjork]
+
+****  Support SV strings to readmemh, bug1040. [Stefan Wallentowitz]
+
+****  Fix unrolling complicated for-loop bounds, bug677. [Johan Bjork]
+
+****  Fix stats file containing multiple unroll entries, bug1020. [Johan Bjork]
+
+****  Fix using short parameter names on negative params, bug1022. [Duraid Madina]
+
+****  Fix read-after-free error, bug1031. [Johan Bjork]
+
+****  Fix elaboration-time display warnings, bug1032. [Johan Bjork]
+
+****  Fix crash on very deep function trees, bug1028. [Jonathan Kimmitt]
+
+****  Fix slicing mix of big and little-endian, bug1033. [Geoff Barrett]
+
+****  Fix pattern assignment width propagation, bug1037. [Johan Bjork]
+
+
+* Verilator 3.880 2015-12-19
+
+***   Support display %u, %v, %p, %z, bug989. [Johan Bjork]
+
+****  Fix real parameters causing bad module names, bug992. [Johan Bjork]
+
+****  Fix size-changing cast on packed struct, bug993. [Johan Bjork]
+
+****  Fix function calls on arrayed interface, bug994. [Johan Bjork]
+
+****  Fix arrayed interfaces, bug879, bug1001. [Todd Strader]
+
+****  Fix constant function assigned to packed structs, bug997. [Johan Bjork]
+
+****  Fix interface inside generate, bug998. [Johan Bjork]
+
+****  Fix $signed casts under generates, bug999. [Clifford Wolf]
+
+****  Fix genvar constant propagation, bug1003. [Johan Bjork]
+
+****  Fix parameter constant propagation from package, bug1004. [Johan Bjork]
+
+****  Fix array slicing of non-const indexes, bug1006. [Johan Bjork]
+
+****  Fix dotted generated array error, bug1005. [Jeff Bush, Johan Bjork]
+
+****  Fix error instead of warning on large concat, msg1768. [Paul Rolfe]
+
+****  Fix $bitstoreal constant propagation, bug1012. [Jonathan Kimmitt]
+
+****  Fix model restore crash, bug1013. [Jason McMullan]
+
+****  Fix arrayed instances to unpacked of same size, bug1015. [Varun Koyyalagunta]
+
+****  Fix slices of unpacked arrays with non-zero LSBs.
+
+****  Fix ternary operation with unpacked array, bug1017. [Varun Koyyalagunta].
+

 * Verilator 3.878 2015-11-01

@@ -2640,12 +2974,12 @@ of input ports exists for tracing.

 This uses outline mode in Emacs.  See C-h m [M-x describe-mode].

-Copyright 2001-2015 by Wilson Snyder.  This program is free software; you
+Copyright 2001-2017 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.

 Local variables:
 mode: outline
-paragraph-separate: "[ 	\f\n]*$"
+paragraph-separate: "[  \f\n]*$"
 end:
@@ -20,6 +20,8 @@
 /cov_work/
 /logs/
 ^Makefile$
+bin/verilator_bin.*
+bin/verilator_coverage_bin.*
 src/Makefile$
 src/Makefile_obj$
 include/verilated.mk$
@@ -39,5 +41,6 @@ nodist/
 /vc_hdrs.h$
 /csrc/
 doxygen-doc/.*
+obj_dir/.*
 TAGS
 .*~
@@ -7,7 +7,7 @@
 #
 #*****************************************************************************
 #
-# Copyright 2003-2015 by Wilson Snyder. This program is free software; you can
+# Copyright 2003-2017 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.
@@ -42,9 +42,6 @@
 #      reconstructed with this Makefile.  This typically includes
 #      everything deleted by distclean, plus more: C source files
 #      produced by Bison, tags tables, info files, and so on.
-#
-# make extraclean
-#      Still more severe - delete backup and autosave files, too.

 #### Start of system configuration section. ####

@@ -71,7 +68,7 @@ exec_prefix = @exec_prefix@
 # Directory in which to install scripts.
 bindir = @bindir@

-# Directory in which to install scripts.
+# Directory in which to install manpages.
 mandir = @mandir@

 # Directory in which to install library files.
@@ -95,14 +92,19 @@ datarootdir = @datarootdir@
 CFG_WITH_CCWARN = @CFG_WITH_CCWARN@
 CFG_WITH_DEFENV = @CFG_WITH_DEFENV@
 CFG_WITH_LONGTESTS = @CFG_WITH_LONGTESTS@
+CFG_WITH_THREADED = @CFG_WITH_THREADED@
 PACKAGE_VERSION = @PACKAGE_VERSION@

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

+.SUFFIXES:
+
 SHELL = /bin/sh

-SUBDIRS = src test_verilated test_c test_sc test_regress
+SUBDIRS = src test_regress \
+	examples/hello_world_c  examples/hello_world_sc \
+	examples/tracing_c  examples/tracing_sc \

 INFOS = README README.html README.pdf internals.txt internals.html \
        internals.pdf verilator.txt verilator.html verilator.pdf \
@@ -115,7 +117,11 @@ DISTFILES_INC = $(INFOS) .gitignore Artistic COPYING COPYING.LESSER \
 	*.in *.ac \
 	Changes TODO \
 	MANIFEST.SKIP \
-	bin/* \
+	bin/verilator \
+	bin/verilator_coverage \
+	bin/verilator_difftree \
+	bin/verilator_includer \
+	bin/verilator_profcfunc \
 	doxygen-mainpage doxygen.config veripool-logo.png \
 	install-sh configure mkinstalldirs *.pod \
 	include/*.[chv]* \
@@ -128,11 +134,14 @@ DISTFILES_INC = $(INFOS) .gitignore Artistic COPYING COPYING.LESSER \
 	src/vlcovgen \
 	src/.gdbinit \
 	src/*.pl src/*.pod \
+	examples/*/.*ignore examples/*/Makefile* \
+	examples/*/*.[chv]* examples/*/*.pl \
 	test_*/.*ignore test_*/Makefile* test_*/*.cpp \
 	test_*/*.pl test_*/*.v test_*/*.vc test_*/*.vh \
-	test_verilated/vgen*.pl \
 	test_regress/t/t*/*.sv* \
 	test_regress/t/t*/*.v* \
+	test_regress/t/t*/*/*.sv* \
+	test_regress/t/t*/*/*.v* \
 	test_regress/t/*.cpp \
 	test_regress/t/*.h \
 	test_regress/t/*.dat \
@@ -152,9 +161,9 @@ INST_PROJ_FILES = \
 	include/vltstd/*.[chv]* \

 INST_PROJ_BIN_FILES = \
-	verilator_bin \
-	verilator_bin_dbg \
-	verilator_coverage_bin_dbg \
+	bin/verilator_bin \
+	bin/verilator_bin_dbg \
+	bin/verilator_coverage_bin_dbg \

 DISTFILES := $(DISTFILES_INC)

@@ -181,33 +190,33 @@ verilator_exe verilator_bin verilator_bin_dbg verilator_coverage_bin_dbg:
 msg_test: all_nomsg
 	@echo "Build complete!"
 	@echo
-	@echo "Type 'make test' to test."
+	@echo "Now type 'make test' to test."
 	@echo

-.PHONY:test
+.PHONY: test
 ifeq ($(CFG_WITH_LONGTESTS),yes)	# Local... Else don't burden users
-test: test_c test_sc test_verilated test_regress
+test: smoke-test examples test_regress
 else
-test: test_c test_sc
+test: smoke-test examples
 endif
 	@echo "Tests passed!"
 	@echo
-	@echo "Type 'make install' to install documentation."
+	@echo "Now type 'make install' to install."
+	@echo "Or type 'make' inside an examples subdirectory."
 	@echo

-test_c: all_nomsg
-	@(cd test_c && $(MAKE))
-test_c_debug: all_nomsg
-	@(cd test_c && $(MAKE) test_debug)
-test_sc: all_nomsg
-	@(cd test_sc && $(MAKE))
-test_sc_debug: all_nomsg
-	@(cd test_sc && $(MAKE) test_debug)
-test_verilated: all_nomsg
-	@(cd test_verilated && $(MAKE))
+smoke-test: all_nomsg
+	test_regress/t/t_a_first_cc.pl
+	test_regress/t/t_a_first_sc.pl
+
 test_regress: all_nomsg
 	@(cd test_regress && $(MAKE))

+examples: all_nomsg
+	for p in examples/* ; do \
+	  $(MAKE) -C $$p VERILATOR_ROOT=`pwd` || exit 10; \
+	done
+
 info: $(INFOS)

 # Use --no-split to avoid creating filenames > 14 chars.
@@ -271,6 +280,7 @@ VL_INST_BIN_FILES = verilator verilator_bin verilator_bin_dbg verilator_coverage
 VL_INST_MAN_FILES = verilator.1 verilator_coverage.1 verilator_profcfunc.1

 VL_INST_INC_BLDDIR_FILES = \
+	include/verilated_config.h \
 	include/verilated.mk \

 # Files under srcdir, instead of build time
@@ -279,18 +289,16 @@ VL_INST_INC_SRCDIR_FILES = \
 	include/vltstd/*.[chv]* \

 VL_INST_DATA_SRCDIR_FILES = \
-	test_v/*.[chv]* \
-	test_c/*.[chv]*   test_c/Makefile  test_c/Makefile_obj  \
-	test_sc/*.[chv]*  test_sc/Makefile test_sc/Makefile_obj \
+	examples/*/*.[chv]*  examples/*/Makefile* \

 installbin:
 	$(SHELL) ${srcdir}/mkinstalldirs $(DESTDIR)$(bindir)
 	( cd ${srcdir}/bin ; $(INSTALL_PROGRAM) verilator $(DESTDIR)$(bindir)/verilator )
 	( cd ${srcdir}/bin ; $(INSTALL_PROGRAM) verilator_coverage $(DESTDIR)$(bindir)/verilator_coverage )
 	( cd ${srcdir}/bin ; $(INSTALL_PROGRAM) verilator_profcfunc $(DESTDIR)$(bindir)/verilator_profcfunc )
-	( $(INSTALL_PROGRAM) verilator_bin $(DESTDIR)$(bindir)/verilator_bin )
-	( $(INSTALL_PROGRAM) verilator_bin_dbg $(DESTDIR)$(bindir)/verilator_bin_dbg )
-	( $(INSTALL_PROGRAM) verilator_coverage_bin_dbg $(DESTDIR)$(bindir)/verilator_coverage_bin_dbg )
+	( cd ${srcdir}/bin ; $(INSTALL_PROGRAM) verilator_bin $(DESTDIR)$(bindir)/verilator_bin )
+	( cd ${srcdir}/bin ; $(INSTALL_PROGRAM) verilator_bin_dbg $(DESTDIR)$(bindir)/verilator_bin_dbg )
+	( cd ${srcdir}/bin ; $(INSTALL_PROGRAM) verilator_coverage_bin_dbg $(DESTDIR)$(bindir)/verilator_coverage_bin_dbg )
 	$(SHELL) ${srcdir}/mkinstalldirs $(DESTDIR)$(pkgdatadir)/bin
 	( cd ${srcdir}/bin ; $(INSTALL_PROGRAM) verilator_includer $(DESTDIR)$(pkgdatadir)/bin/verilator_includer )

@@ -298,7 +306,8 @@ installbin:
 # So important we use $< so VPATH is searched
 installman: $(VL_INST_MAN_FILES)
 	$(SHELL) ${srcdir}/mkinstalldirs $(DESTDIR)$(mandir)/man1
-	for p in $^ ; do \
+	cd $(srcdir) \
+	; for p in $(VL_INST_MAN_FILES) ; do \
 	  $(INSTALL_DATA) $$p $(DESTDIR)$(mandir)/man1/$$p; \
 	done

@@ -311,12 +320,13 @@ installdata:
 	; for p in $(VL_INST_INC_SRCDIR_FILES) ; do \
 	  $(INSTALL_DATA) $$p $(DESTDIR)$(pkgdatadir)/$$p; \
 	done
-	$(SHELL) ${srcdir}/mkinstalldirs $(DESTDIR)$(pkgdatadir)/examples/test_c
-	$(SHELL) ${srcdir}/mkinstalldirs $(DESTDIR)$(pkgdatadir)/examples/test_sc
-	$(SHELL) ${srcdir}/mkinstalldirs $(DESTDIR)$(pkgdatadir)/examples/test_v
+	$(SHELL) ${srcdir}/mkinstalldirs $(DESTDIR)$(pkgdatadir)/examples/hello_world_c
+	$(SHELL) ${srcdir}/mkinstalldirs $(DESTDIR)$(pkgdatadir)/examples/hello_world_sc
+	$(SHELL) ${srcdir}/mkinstalldirs $(DESTDIR)$(pkgdatadir)/examples/tracing_c
+	$(SHELL) ${srcdir}/mkinstalldirs $(DESTDIR)$(pkgdatadir)/examples/tracing_sc
 	cd $(srcdir) \
 	; for p in $(VL_INST_DATA_SRCDIR_FILES) ; do \
-	  $(INSTALL_DATA) $$p $(DESTDIR)$(pkgdatadir)/examples/$$p; \
+	  $(INSTALL_DATA) $$p $(DESTDIR)$(pkgdatadir)/$$p; \
 	done
 	$(SHELL) ${srcdir}/mkinstalldirs $(DESTDIR)$(pkgconfigdir)
 	$(INSTALL_DATA) verilator.pc $(DESTDIR)$(pkgconfigdir)
@@ -328,15 +338,15 @@ uninstall:
 	-cd $(DESTDIR)$(mandir)/man1 && rm -f $(VL_INST_MAN_FILES)
 	-cd $(DESTDIR)$(pkgdatadir) && rm -f $(VL_INST_INC_BLDDIR_FILES)
 	-cd $(DESTDIR)$(pkgdatadir) && rm -f $(VL_INST_INC_SRCDIR_FILES)
-	-cd $(DESTDIR)$(pkgdatadir)/examples && rm -f $(VL_INST_DATA_SRCDIR_FILES)
+	-cd $(DESTDIR)$(pkgdatadir) && rm -f $(VL_INST_DATA_SRCDIR_FILES)
 	-rm $(DESTDIR)$(pkgconfigdir)/verilator.pc
 	-rmdir $(DESTDIR)$(pkgdatadir)/bin
 	-rmdir $(DESTDIR)$(pkgdatadir)/include/vltstd
 	-rmdir $(DESTDIR)$(pkgdatadir)/include
-	-rmdir $(DESTDIR)$(pkgdatadir)/examples/test_c
-	-rmdir $(DESTDIR)$(pkgdatadir)/examples/test_sc
-	-rmdir $(DESTDIR)$(pkgdatadir)/examples/test_sp
-	-rmdir $(DESTDIR)$(pkgdatadir)/examples/test_v
+	-rmdir $(DESTDIR)$(pkgdatadir)/examples/hello_world_c
+	-rmdir $(DESTDIR)$(pkgdatadir)/examples/hello_world_sc
+	-rmdir $(DESTDIR)$(pkgdatadir)/examples/tracing_c
+	-rmdir $(DESTDIR)$(pkgdatadir)/examples/tracing_sc
 	-rmdir $(DESTDIR)$(pkgdatadir)/examples
 	-rmdir $(DESTDIR)$(pkgdatadir)
 	-rmdir $(DESTDIR)$(pkgconfigdir)
@@ -355,8 +365,8 @@ INST_PROJ_CVS = cp_if_cvs_diff

 install-project: dist
 	@echo "Install-project to $(DIRPROJECT)"
-	strip verilator_bin*
-	strip verilator_coverage_bin*
+	strip bin/verilator_bin*
+	strip bin/verilator_coverage_bin*
 	$(MAKE) install-project-quick
 	for p in $(VL_INST_MAN_FILES) ; do \
 	  $(INSTALL_DATA) $$p $(DIRPROJECT_PREFIX)/man/man1/$$p; \
@@ -379,8 +389,8 @@ endif

 install-cadtools: dist
 	@echo "Install-project to $(CAD_DIR)"
-	strip verilator_bin*
-	strip verilator_coverage_bin*
+	strip bin/verilator_bin*
+	strip bin/verilator_coverage_bin*
 	$(MAKE) install-cadtools-quick
 	$(SHELL) ${srcdir}/mkinstalldirs $(VERILATOR_CAD_DIR)/man/man1
 	for p in $(VL_INST_MAN_FILES) ; do \
@@ -418,12 +428,23 @@ CPPCHECK_INC = -I$(srcdir)/include -I$(srcdir)/src/obj_dbg -I$(srcdir)/src

 cppcheck: $(CPPCHECK_DEP)
 %.cppcheck: %.cpp
-	$(CPPCHECK) $(CPPCHECK_FLAGS) -DVL_DEBUG=1 $(CPPCHECK_INC) $<
+	$(CPPCHECK) $(CPPCHECK_FLAGS) -DVL_DEBUG=1 -DVL_CPPCHECK=1 $(CPPCHECK_INC) $<
+
+analyzer-src:
+	-rm -rf src/obj_dbg
+	scan-build $(MAKE) -k verilator_coverage_bin_dbg verilator_bin_dbg
+
+analyzer-include:
+	-rm -rf examples/*/obj*
+	scan-build $(MAKE) -k examples

 ftp: info

 install-msg:
-	@echo "Installed!"
+	@echo
+	@echo "Installed binaries to $(DESTDIR)$(bindir)/verilator"
+	@echo "Installed man to $(DESTDIR)$(mandir)/man1"
+	@echo "Installed examples to $(DESTDIR)$(pkgdatadir)/examples"
 	@echo
 	@echo "For documentation see 'man verilator' or 'verilator --help'"
 	@echo "For forums and to report bugs see http://www.veripool.org/verilator"
@@ -451,7 +472,7 @@ endif
 maintainer-clean::
 	@echo "This command is intended for maintainers to use;"
 	@echo "rebuilding the deleted files requires makeinfo."
-	rm -f *.info* $(INFOS) configure
+	rm -f *.info* *.1 $(INFOS) configure

 clean mostlyclean distclean maintainer-clean maintainer-copy::
 	for dir in $(SUBDIRS); do \
@@ -465,10 +486,13 @@ clean mostlyclean distclean maintainer-clean::
 	rm -f *.pg *.pgs *.toc *.tp *.tps *.vr *.vrs *.idx
 	rm -f *.ev *.evs *.ov *.ovs *.cv *.cvs *.ma *.mas
 	rm -f *.tex
+	rm -rf test_*/obj_dir
+	rm -rf examples/*/obj_dir examples/*/logs

 distclean maintainer-clean::
 	rm -f Makefile config.status config.cache config.log TAGS
 	rm -f verilator_bin* verilator_coverage_bin*
+	rm -f bin/verilator_bin* bin/verilator_coverage_bin*
 	rm -f include/verilated.mk include/verilated_config.h

 TAGFILES=${srcdir}/*/*.cpp ${srcdir}/*/*.h ${srcdir}/*/*.in \
@@ -490,6 +514,9 @@ dist-file-list:
 	@echo $(wildcard $(DISTFILES))
 	@echo "end-dist-file-list:";  # Scripts look for this

+print-cfg-with-threaded:
+	@echo $(CFG_WITH_THREADED)
+
 ######################################################################
 # Distributions

@@ -11,7 +11,7 @@ This is the Verilator package README file.

 http://www.veripool.org/verilator

-This package is Copyright 2003-2015 by Wilson Snyder.  (Report bugs to
+This package is Copyright 2003-2017 by Wilson Snyder.  (Report bugs to
 L<http://www.veripool.org/>.)

 Verilator is free software; you can redistribute it and/or modify it under
@@ -51,7 +51,7 @@ output (not Verilator itself) compiles under MSVC++ 2008 and newer.

 =head1 INSTALLATION

-For more details see 
+For more details see
 L<http://www.veripool.org/projects/verilator/wiki/Installing>.

 If you will be modifying Verilator, you should use the "git" method as it
@@ -169,6 +169,9 @@ have the verilator binary directory in your PATH (this should already be
 true if using the default configure), and make sure VERILATOR_ROOT is not
 set.

+You may now wish to consult the examples directory. Type C<make> inside any
+example directory to run the example.
+
 =back

 =head1 USAGE DOCUMENTATION
@@ -190,10 +193,10 @@ The directories in the kit after de-taring are as follows:
    include/verilated.v         => Stub defines for linting
    include/verilated.mk        => Common makefile
    src/                        => Translator source code
-    test_v                      => Example Verilog code for other test dirs
-    test_c                      => Example Verilog->C++ conversion
-    test_sc                     => Example Verilog->SystemC conversion
-    test_verilated              => Internal tests
+    examples/hello_world_c      => Example simple Verilog->C++ conversion
+    examples/hello_world_sc     => Example simple Verilog->SystemC conversion
+    examples/tracing_c          => Example Verilog->C++ with tracing
+    examples/tracing_sc         => Example Verilog->SystemC with tracing
    test_regress                => Internal tests

 =head1 LIMITATIONS
@@ -1,6 +1,6 @@
 // DESCRIPTION: Verilator: List of To Do issues.
 //
-// Copyright 2004-2015 by Wilson Snyder. This program is free software; you can
+// Copyright 2004-2017 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.
@@ -41,7 +41,7 @@ Testing:
 	* // verilator debug in code so can see only tree affecting those nodes

 Usability:
-	* Detect and pre-remove most UNOPTFLATs (4.000) 
+	* Detect and pre-remove most UNOPTFLATs (4.000)
 	* Better reporting of unopt problems, including what lines of code
 	* Report more errors (all of them?) before exiting [Eugene Weber]
 	* Auto-create scons config files
@@ -3,7 +3,7 @@ eval 'exec perl -wS $0 ${1+"$@"}'
  if 0;
 ######################################################################
 #
-# Copyright 2003-2015 by Wilson Snyder. This program is free software; you
+# Copyright 2003-2017 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.
@@ -173,7 +173,7 @@ additional points.
 Additional Verilog-standard arguments specify the search paths necessary to
 find the source code that the coverage analysis was performed on.

-To get correct coverage percentages, you may wish to read logs/coverage.pl
+To get correct coverage percentages, you may wish to read logs/coverage.dat
 into Emacs and do a M-x keep-lines to include only those statistics of
 interest.

@@ -271,7 +271,7 @@ Specifies a module search directory.

 The latest version is available from L<http://www.veripool.org/>.

-Copyright 2003-2015 by Wilson Snyder.  Verilator is free software; you can
+Copyright 2003-2017 by Wilson Snyder.  Verilator is free software; you can
 redistribute it and/or modify the Verilator internals under the terms of
 either the GNU Lesser General Public License Version 3 or the Perl Artistic
 License Version 2.0.
@@ -235,7 +235,7 @@ Do not show differences in line numbering.

 The latest version is available from L<http://www.veripool.org/verilator>.

-Copyright 2005-2015 by Wilson Snyder.  This package is free software; you can
+Copyright 2005-2017 by Wilson Snyder.  This package 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.

@@ -3,7 +3,7 @@ eval 'exec perl -wS $0 ${1+"$@"}'
  if 0;
 # DESCRIPTION: Print include statements for each ARGV
 #
-# Copyright 2003-2015 by Wilson Snyder. This package is free software; you can
+# Copyright 2003-2017 by Wilson Snyder. This package 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.
 ######################################################################
@@ -13,8 +13,8 @@ use warnings;
 print "// DESCR"."IPTION: Generated by verilator_includer via makefile\n";
 foreach my $param (@ARGV) {
    if ($param =~ /^-D([^=]+)=(.*)/) {
-	print "#define $1 $2\n"
+        print "#define $1 $2\n"
    } else {
-	print "#include \"$param\"\n"
+        print "#include \"$param\"\n"
    }
 }
@@ -222,7 +222,7 @@ Displays this message and program version and exits.

 The latest version is available from L<http://www.veripool.org/>.

-Copyright 2007-2015 by Wilson Snyder.  Verilator is free software; you can
+Copyright 2007-2017 by Wilson Snyder.  Verilator 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.

@@ -1,13 +1,14 @@
 # DESCRIPTION: Process this file with autoconf to produce a configure script.
 #
-# Copyright 2003-2015 by Wilson Snyder. Verilator is free software; you can
+# Copyright 2003-2017 by Wilson Snyder. Verilator 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.

 #AC_INIT([Verilator],[#.### YYYY-MM-DD])
 #AC_INIT([Verilator],[#.### devel])
-AC_INIT([Verilator],[3.878 2015-11-01])
+AC_INIT([Verilator],[3.916 2017-11-25])
 # When releasing, also update header of Changes file
+# and commit using "devel release" or "Version bump" message

 AC_CONFIG_HEADER(src/config_build.h)
 AC_CONFIG_FILES(Makefile src/Makefile src/Makefile_obj include/verilated.mk include/verilated_config.h verilator.pc)
@@ -15,7 +16,7 @@ AC_CONFIG_FILES(Makefile src/Makefile src/Makefile_obj include/verilated.mk incl
 AC_MSG_RESULT([configuring for $PACKAGE_STRING])

 # Special Substitutions - CFG_WITH_DEFENV
-AC_MSG_CHECKING(whether to disable hardcoded paths)
+AC_MSG_CHECKING(whether to use hardcoded paths)
 AC_ARG_ENABLE([defenv],
              [AS_HELP_STRING([--disable-defenv],
                              [disable using some hardcoded data paths extracted from some default environment variables (the default is to use hardcoded paths)])],
@@ -42,7 +43,7 @@ AC_ARG_ENABLE([ccwarn],
                x)   CFG_WITH_CCWARN=no ;;
                *)   CFG_WITH_CCWARN=yes ;;
               esac]
-	      )
+              )
 AC_SUBST(CFG_WITH_CCWARN)
 AC_MSG_RESULT($CFG_WITH_CCWARN)

@@ -60,7 +61,7 @@ AC_ARG_ENABLE([longtests],
                x)   CFG_WITH_LONGTESTS=no ;;
                *)   CFG_WITH_LONGTESTS=yes ;;
               esac]
-	      )
+              )
 AC_SUBST(CFG_WITH_LONGTESTS)
 AC_MSG_RESULT($CFG_WITH_LONGTESTS)

@@ -78,10 +79,10 @@ AC_PROG_INSTALL
 AC_LANG_PUSH(C++)
 AC_MSG_CHECKING([that C++ compiler can compile simple program])
 AC_RUN_IFELSE(
-           [AC_LANG_SOURCE([int main() { return 0; }])],
-           AC_MSG_RESULT(yes),
-           AC_MSG_RESULT(no);AC_MSG_ERROR([a working C++ compiler is required]),
-	   AC_MSG_RESULT(yes))
+   [AC_LANG_SOURCE([int main() { return 0; }])],
+    AC_MSG_RESULT(yes),
+    AC_MSG_RESULT(no);AC_MSG_ERROR([a working C++ compiler is required]),
+    AC_MSG_RESULT(yes))

 AC_PATH_PROG(PERL,perl)
 if test "x$PERL" = "x" ; then
@@ -105,58 +106,148 @@ AC_TYPE_SIZE_T
 # Checks for compiler characteristics.
 AC_C_INLINE

-AC_DEFUN([_MY_CXX_CHECK_OPT],
-   [# _MY_CXX_CHECK_OPT(flag) -- Check if compiler supports specific options
+AC_LINK_IFELSE(
+     [AC_LANG_PROGRAM([#include <new>], [[int* a=new int; delete a; ]])],
+     [], [AC_MSG_ERROR([$CXX does not seem to successfully compile a simple C++ program])])
+
+AC_DEFUN([_MY_CXX_CHECK_FLAG],
+   [# _MY_CXX_CHECK_FLAG(flag) -- Check if compiler supports specific options
+    # Set $_my_result appropriately
    ACO_SAVE_CXXFLAGS="$CXXFLAGS"
    # -Werror needed otherwise unknown -Wno-div-by-zero won't report problems
-    CXXFLAGS="$CXXFLAGS $2 -Werror"
-    AC_MSG_CHECKING([whether $CXX accepts $2])
+    # new/delete is needed to find -faligned-new link problem on Darwin
+    CXXFLAGS="$CXXFLAGS $1 -Werror"
+    AC_MSG_CHECKING([whether $CXX accepts $1])
+    AC_LINK_IFELSE(
+         [AC_LANG_PROGRAM([#include <new>], [[int* a=new int; delete a; ]])],
+         [_my_result=yes
+          if test -s conftest.err; then
+            if grep -e "$1" conftest.err >/dev/null; then
+              _my_result=no
+            fi
+          fi],
+         [_my_result=no])
+    # GCC is annoying, trying to be helpful, it postpones unknown -Wno-
+    # options if there's no error We want to see them regardless, so try
+    # forcing an error and see if we get a gcc warning
    AC_COMPILE_IFELSE(
-         [AC_LANG_PROGRAM([],[])],
-	 [_my_result=yes
-	  if test -s conftest.err; then
-	    if grep -e "$2" conftest.err >/dev/null; then
-	      _my_result=no
-	    fi
-	  fi],
-	 [_my_result=no])
+         [AC_LANG_PROGRAM([[an_error "intentional-error-for-test.h"
+                          ]],[])],
+         [], # Ignore ok exit
+         [if test -s conftest.err; then
+            if grep -e "$1" conftest.err >/dev/null; then
+              _my_result=no
+            fi
+          fi])
    AC_MSG_RESULT($_my_result)
+    CXXFLAGS="$ACO_SAVE_CXXFLAGS"
+   ])
+
+AC_DEFUN([_MY_CXX_CHECK_SET],
+   [# _MY_CXX_CHECK_SET(variable,flag) -- Check if compiler supports specific options
+    # If it does, set variable to flag, only if not previously set
+    if test "$$1" = ""; then
+       _MY_CXX_CHECK_FLAG($2)
+       if test "$_my_result" = "yes" ; then
+          $1="$2"
+       fi
+    fi
+   ])
+
+AC_DEFUN([_MY_CXX_CHECK_OPT],
+   [# _MY_CXX_CHECK_OPT(flag) -- Check if compiler supports specific options
+    # If it does, append flag to variable
+    _MY_CXX_CHECK_FLAG($2)
    if test "$_my_result" = "yes" ; then
       $1="$$1 $2"
    fi
-    CXXFLAGS="$ACO_SAVE_CXXFLAGS"
-   ])# _MY_CXX_CHECK_OPT
+   ])

-# Flags for compiling Verilator internals including parser
-_MY_CXX_CHECK_OPT(CFG_CXXFLAGS_SRC,-Wno-unused-parameter)
-_MY_CXX_CHECK_OPT(CFG_CXXFLAGS_SRC,-Wno-char-subscripts)
+# Flag to select newest language standard supported
+# Macros work such that first option that passes is the one we take
+# gnu++14 is the newest that Verilator supports
+# std++03 is the oldest that Verilator supports
+_MY_CXX_CHECK_SET(CFG_CXXFLAGS_STD_NEWEST,-std=gnu++14)
+_MY_CXX_CHECK_SET(CFG_CXXFLAGS_STD_NEWEST,-std=gnu++11)
+_MY_CXX_CHECK_SET(CFG_CXXFLAGS_STD_NEWEST,-std=gnu++03)
+_MY_CXX_CHECK_SET(CFG_CXXFLAGS_STD_NEWEST,-std=c++14)
+_MY_CXX_CHECK_SET(CFG_CXXFLAGS_STD_NEWEST,-std=c++11)
+_MY_CXX_CHECK_SET(CFG_CXXFLAGS_STD_NEWEST,-std=c++03)
+AC_SUBST(CFG_CXXFLAGS_STD_NEWEST)
+# And likewise oldest standard (same list above, backwards)
+# This is used for internal testing
+_MY_CXX_CHECK_SET(CFG_CXXFLAGS_STD_OLDEST,-std=std++03)
+_MY_CXX_CHECK_SET(CFG_CXXFLAGS_STD_OLDEST,-std=std++11)
+_MY_CXX_CHECK_SET(CFG_CXXFLAGS_STD_OLDEST,-std=std++14)
+_MY_CXX_CHECK_SET(CFG_CXXFLAGS_STD_OLDEST,-std=gnu++03)
+_MY_CXX_CHECK_SET(CFG_CXXFLAGS_STD_OLDEST,-std=gnu++11)
+_MY_CXX_CHECK_SET(CFG_CXXFLAGS_STD_OLDEST,-std=gnu++14)
+_MY_CXX_CHECK_SET(CFG_CXXFLAGS_STD_OLDEST,-std=gnu++17)
+AC_SUBST(CFG_CXXFLAGS_STD_OLDEST)
+
+# Flags for compiling Verilator internals including parser, and Verilated files
+# These turn on extra warnings and are only used with 'configure --enable-ccwarn'
+_MY_CXX_CHECK_OPT(CFG_CXXFLAGS_WEXTRA,-Wextra)
+_MY_CXX_CHECK_OPT(CFG_CXXFLAGS_WEXTRA,-Wfloat-conversion)
+_MY_CXX_CHECK_OPT(CFG_CXXFLAGS_WEXTRA,-Wlogical-op)
+_MY_CXX_CHECK_OPT(CFG_CXXFLAGS_WEXTRA,-Wthread-safety)
+AC_SUBST(CFG_CXXFLAGS_WEXTRA)
+
+# Flags for compiling Verilator internals including parser always
 _MY_CXX_CHECK_OPT(CFG_CXXFLAGS_SRC,-Qunused-arguments)
+_MY_CXX_CHECK_OPT(CFG_CXXFLAGS_SRC,-faligned-new)
+_MY_CXX_CHECK_OPT(CFG_CXXFLAGS_SRC,-fno-delete-null-pointer-checks)
+_MY_CXX_CHECK_OPT(CFG_CXXFLAGS_SRC,-Wno-unused-parameter)
+_MY_CXX_CHECK_OPT(CFG_CXXFLAGS_SRC,-Wno-undefined-bool-conversion)
+_MY_CXX_CHECK_OPT(CFG_CXXFLAGS_SRC,-Wno-shadow)
 AC_SUBST(CFG_CXXFLAGS_SRC)

-# Flags for compiling Verilator parser
-_MY_CXX_CHECK_OPT(CFG_CXXFLAGS_PARSER,-Wno-unused)
-_MY_CXX_CHECK_OPT(CFG_CXXFLAGS_PARSER,-Wno-parentheses-equality)
+# Flags for compiling Verilator parser always (in addition to above CFG_CXXFLAGS_SRC)
+_MY_CXX_CHECK_OPT(CFG_CXXFLAGS_PARSER,-Wno-char-subscripts)
 _MY_CXX_CHECK_OPT(CFG_CXXFLAGS_PARSER,-Wno-null-conversion)
+_MY_CXX_CHECK_OPT(CFG_CXXFLAGS_PARSER,-Wno-parentheses-equality)
+_MY_CXX_CHECK_OPT(CFG_CXXFLAGS_PARSER,-Wno-unused)
 AC_SUBST(CFG_CXXFLAGS_PARSER)

 # Flags for Verilated makefile
 # For example, -Wno-div-by-zero isn't in 4.1.2
-_MY_CXX_CHECK_OPT(CFG_CXXFLAGS_NO_UNUSED,-Wno-char-subscripts)
-_MY_CXX_CHECK_OPT(CFG_CXXFLAGS_NO_UNUSED,-Wno-parentheses-equality)
 # Random code often does / 0.  Unfortunately VL_DIV_I(0,0) will warn
 # without this flag, even though there's a conditional to prevent the divide.
 # We still don't add no-div-by-zero as it throws message to stdout, though doesn't die.
 #_MY_CXX_CHECK_OPT(-Wno-div-by-zero)
+_MY_CXX_CHECK_OPT(CFG_CXXFLAGS_NO_UNUSED,-faligned-new)
+_MY_CXX_CHECK_OPT(CFG_CXXFLAGS_NO_UNUSED,-fbracket-depth=4096)
+_MY_CXX_CHECK_OPT(CFG_CXXFLAGS_NO_UNUSED,-Qunused-arguments)
+_MY_CXX_CHECK_OPT(CFG_CXXFLAGS_NO_UNUSED,-Wno-parentheses-equality)
 _MY_CXX_CHECK_OPT(CFG_CXXFLAGS_NO_UNUSED,-Wno-sign-compare)
 _MY_CXX_CHECK_OPT(CFG_CXXFLAGS_NO_UNUSED,-Wno-uninitialized)
 _MY_CXX_CHECK_OPT(CFG_CXXFLAGS_NO_UNUSED,-Wno-unused-but-set-variable)
 _MY_CXX_CHECK_OPT(CFG_CXXFLAGS_NO_UNUSED,-Wno-unused-parameter)
 _MY_CXX_CHECK_OPT(CFG_CXXFLAGS_NO_UNUSED,-Wno-unused-variable)
-_MY_CXX_CHECK_OPT(CFG_CXXFLAGS_NO_UNUSED,-fbracket-depth=4096)
-_MY_CXX_CHECK_OPT(CFG_CXXFLAGS_NO_UNUSED,-Qunused-arguments)
+_MY_CXX_CHECK_OPT(CFG_CXXFLAGS_NO_UNUSED,-Wno-shadow)
 AC_SUBST(CFG_CXXFLAGS_NO_UNUSED)

+# Set CFG_WITH_THREADED if can support threading
+AC_MSG_CHECKING(whether $CXX supports Verilated threads)
+ACO_SAVE_CXXFLAGS="$CXXFLAGS"
+CXXFLAGS="$CXXFLAGS $CFG_CXXFLAGS_STD_NEWEST $CFG_CXXFLAGS_NO_UNUSED"
+AC_LINK_IFELSE(
+     [AC_LANG_PROGRAM([#include <thread>], [[ ]])],
+     [_my_result=yes
+      if test -s conftest.err; then
+        if grep -e "$1" conftest.err >/dev/null; then
+          _my_result=no
+        fi
+      fi],
+     [_my_result=no])
+CFG_WITH_THREADED=$_my_result
+AC_SUBST(CFG_WITH_THREADED)
+AC_MSG_RESULT($CFG_WITH_THREADED)
+
 # Checks for library functions.
+AC_CHECK_MEMBER([struct stat.st_mtim.tv_nsec],
+    [AC_DEFINE([HAVE_STAT_NSEC],[1],[Defined if struct stat has st_mtim.tv_nsec])],
+    [], [#include <sys/stat.h>])

 # Checks for system services

@@ -635,8 +635,7 @@ INPUT                  = doxygen-mainpage \
                         test_c \
                         test_regress \
                         test_sc \
-                         test_v \
-                         test_verilated
+                         test_v

 # This tag can be used to specify the character encoding of the source files
 # that doxygen parses. Internally doxygen uses the UTF-8 encoding, which is
@@ -3,4 +3,4 @@
 *.csrc
 *.vcd
 obj_*
-project
+logs
@@ -0,0 +1,52 @@
+######################################################################
+#
+# DESCRIPTION: Verilator Example: Small Makefile
+#
+# This calls the object directory makefile.  That allows the objects to
+# be placed in the "current directory" which simplifies the Makefile.
+#
+# Copyright 2003-2017 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.
+#
+######################################################################
+# Check for sanity to avoid later confusion
+
+ifneq ($(words $(CURDIR)),1)
+ $(error Unsupported: GNU Make cannot build in directories containing spaces, build elsewhere: '$(CURDIR)')
+endif
+
+######################################################################
+
+# This is intended to be a minimal example.  Before copying this to start a
+# real project, it is better to start with a more complete example,
+# e.g. examples/tracing_c.
+
+# If $VERILATOR_ROOT isn't in the enviornment, we assume it is part of a
+# package inatall, and verilator is in your path. Otherwise find the
+# binary relative to $VERILATOR_ROOT (such as when inside the git sources).
+ifeq ($(VERILATOR_ROOT),)
+VERILATOR = verilator
+else
+export VERILATOR_ROOT
+VERILATOR = $(VERILATOR_ROOT)/bin/verilator
+endif
+
+default:
+	@echo "-- Verilator hello-world simple example"
+	@echo "-- VERILATE ----------------"
+	$(VERILATOR) -cc --exe top.v sim_main.cpp
+	@echo "-- COMPILE -----------------"
+	$(MAKE) -j 4 -C obj_dir -f Vtop.mk
+	@echo "-- RUN ---------------------"
+	obj_dir/Vtop
+	@echo "-- DONE --------------------"
+	@echo "Note: Once this example is understood, see examples/tracing_c."
+	@echo "Note: Also see the EXAMPLE section in the verilator manpage/document."
+
+######################################################################
+
+maintainer-copy::
+clean mostlyclean distclean maintainer-clean::
+	-rm -rf obj_dir *.log *.dmp *.vpd core
@@ -0,0 +1,41 @@
+// DESCRIPTION: Verilator: Verilog example module
+//
+// This file ONLY is placed into the Public Domain, for any use,
+// without warranty, 2017 by Wilson Snyder.
+//======================================================================
+
+// Include common routines
+#include <verilated.h>
+
+// Include model header, generated from Verilating "top.v"
+#include "Vtop.h"
+
+int main(int argc, char** argv, char** env) {
+    // See a similar example walkthrough in the verilator manpage.
+
+    // This is intended to be a minimal example.  Before copying this to start a
+    // real project, it is better to start with a more complete example,
+    // e.g. examples/c_tracing.
+
+    // Prevent unused variable warnings
+    if (0 && argc && argv && env) {}
+
+    // Construct the Verilated model, from Vtop.h generated from Verilating "top.v"
+    Vtop* top = new Vtop;
+
+    // Simulate until $finish
+    while (!Verilated::gotFinish()) {
+
+        // Evaluate model
+        top->eval();
+    }
+
+    // Final model cleanup
+    top->final();
+
+    // Destroy model
+    delete top;
+
+    // Fin
+    exit(0);
+}
@@ -0,0 +1,12 @@
+// DESCRIPTION: Verilator: Verilog example module
+//
+// This file ONLY is placed into the Public Domain, for any use,
+// without warranty, 2017 by Wilson Snyder.
+
+// See also the EXAMPLE section in the verilator manpage/document.
+module top;
+   initial begin
+      $display("Hello World!");
+      $finish;
+   end
+endmodule
@@ -1,8 +1,6 @@
-*.old
 *.dmp
 *.log
 *.csrc
 *.vcd
 obj_*
 logs
-project
@@ -0,0 +1,67 @@
+######################################################################
+#
+# DESCRIPTION: Verilator Example: Small Makefile
+#
+# This calls the object directory makefile.  That allows the objects to
+# be placed in the "current directory" which simplifies the Makefile.
+#
+# Copyright 2003-2017 by Wilson Snyder. This program is free software; you can
+# redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+#
+######################################################################
+# Check for sanity to avoid later confusion
+
+ifneq ($(words $(CURDIR)),1)
+ $(error Unsupported: GNU Make cannot build in directories containing spaces, build elsewhere: '$(CURDIR)')
+endif
+
+######################################################################
+
+# This is intended to be a minimal example.  Before copying this to start a
+# real project, it is better to start with a more complete example,
+# e.g. examples/tracing_sc.
+
+# If $VERILATOR_ROOT isn't in the enviornment, we assume it is part of a
+# package inatall, and verilator is in your path. Otherwise find the
+# binary relative to $VERILATOR_ROOT (such as when inside the git sources).
+ifeq ($(VERILATOR_ROOT),)
+VERILATOR = verilator
+else
+export VERILATOR_ROOT
+VERILATOR = $(VERILATOR_ROOT)/bin/verilator
+endif
+
+# Check if SC exists via a verilator call (empty if not)
+SYSTEMC_EXISTS := $(shell $(VERILATOR) --getenv SYSTEMC_INCLUDE)
+
+ifneq ($(SYSTEMC_EXISTS),)
+default: run
+else
+default: nosc
+endif
+
+run:
+	@echo "-- Verilator hello-world simple example"
+	@echo "-- VERILATE ----------------"
+	$(VERILATOR) -sc --exe top.v sc_main.cpp
+	@echo "-- COMPILE -----------------"
+	$(MAKE) -j 4 -C obj_dir -f Vtop.mk
+	@echo "-- RUN ---------------------"
+	obj_dir/Vtop
+	@echo "-- DONE --------------------"
+	@echo "Note: Once this example is understood, see examples/tracing_sc."
+	@echo "Note: Also see the EXAMPLE section in the verilator manpage/document."
+
+######################################################################
+
+nosc:
+	@echo
+	@echo "%Skip: SYSTEMC_INCLUDE not in environment"
+	@echo "(If you have SystemC see the README, and rebuild Verilator)"
+	@echo
+
+maintainer-copy::
+clean mostlyclean distclean maintainer-clean::
+	-rm -rf obj_dir *.log *.dmp *.vpd core
@@ -0,0 +1,51 @@
+// -*- SystemC -*-
+// DESCRIPTION: Verilator Example: Top level main for invoking SystemC model
+//
+// This file ONLY is placed into the Public Domain, for any use,
+// without warranty, 2017 by Wilson Snyder.
+//======================================================================
+
+// SystemC global header
+#include <systemc.h>
+
+// Include common routines
+#include <verilated.h>
+
+// Include model header, generated from Verilating "top.v"
+#include "Vtop.h"
+
+int sc_main(int argc, char* argv[]) {
+    // See a similar example walkthrough in the verilator manpage.
+
+    // This is intended to be a minimal example.  Before copying this to start a
+    // real project, it is better to start with a more complete example,
+    // e.g. examples/c_tracing.
+
+    // Prevent unused variable warnings
+    if (0 && argc && argv) {}
+
+    // Construct the Verilated model, from Vtop.h generated from Verilating "top.v"
+    Vtop* top = new Vtop("top");
+
+    // Initialize SC model
+#if (SYSTEMC_VERSION>=20070314)
+    sc_start(1,SC_NS);
+#else
+    sc_start(1);
+#endif
+
+    // Simulate until $finish
+    while (!Verilated::gotFinish()) {
+#if (SYSTEMC_VERSION>=20070314)
+        sc_start(1,SC_NS);
+#else
+        sc_start(1);
+#endif
+    }
+
+    // Final model cleanup
+    top->final();
+
+    // Fin
+    return 0;
+}
@@ -0,0 +1,12 @@
+// DESCRIPTION: Verilator: Verilog example module
+//
+// This file ONLY is placed into the Public Domain, for any use,
+// without warranty, 2017 by Wilson Snyder.
+
+// See also the EXAMPLE section in the verilator manpage/document.
+module top;
+   initial begin
+      $display("Hello World!");
+      $finish;
+   end
+endmodule
@@ -0,0 +1,6 @@
+*.dmp
+*.log
+*.csrc
+*.vcd
+obj_*
+logs
@@ -0,0 +1,96 @@
+######################################################################
+#
+# DESCRIPTION: Verilator Example: Small Makefile
+#
+# This calls the object directory makefile.  That allows the objects to
+# be placed in the "current directory" which simplifies the Makefile.
+#
+# Copyright 2003-2017 by Wilson Snyder. This program is free software; you can
+# redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+#
+######################################################################
+# Check for sanity to avoid later confusion
+
+ifneq ($(words $(CURDIR)),1)
+ $(error Unsupported: GNU Make cannot build in directories containing spaces, build elsewhere: '$(CURDIR)')
+endif
+
+######################################################################
+# Set up variables
+
+# If $VERILATOR_ROOT isn't in the enviornment, we assume it is part of a
+# package inatall, and verilator is in your path. Otherwise find the
+# binary relative to $VERILATOR_ROOT (such as when inside the git sources).
+ifeq ($(VERILATOR_ROOT),)
+VERILATOR = verilator
+VERILATOR_COVERAGE = verilator_coverage
+else
+export VERILATOR_ROOT
+VERILATOR = $(VERILATOR_ROOT)/bin/verilator
+VERILATOR_COVERAGE = $(VERILATOR_ROOT)/bin/verilator_coverage
+endif
+
+VERILATOR_FLAGS =
+# Generate C++ in executable form
+VERILATOR_FLAGS += -cc --exe
+# Generate makefile dependencies (not shown as complicates the Makefile)
+#VERILATOR_FLAGS += -MMD
+# Optimize
+VERILATOR_FLAGS += -O2 -x-assign 0
+# Warn abount lint issues; may not want this on less solid designs
+VERILATOR_FLAGS += -Wall
+# Make waveforms
+VERILATOR_FLAGS += --trace
+# Check SystemVerilog assertions
+VERILATOR_FLAGS += --assert
+# Generate coverage analysis
+VERILATOR_FLAGS += --coverage
+# Run Verilator in debug mode
+#VERILATOR_FLAGS += --debug
+# Add this trace to get a backtrace in gdb
+#VERILATOR_FLAGS += --gdbbt
+
+######################################################################
+default: run
+
+run:
+	@echo
+	@echo "-- Verilator tracing example"
+
+	@echo
+	@echo "-- VERILATE ----------------"
+	$(VERILATOR) $(VERILATOR_FLAGS) -f input.vc top.v sim_main.cpp
+
+	@echo
+	@echo "-- COMPILE -----------------"
+# To compile, we can either just do what Verilator asks,
+# or call a submakefile where we can override the rules ourselves
+#	$(MAKE) -j 4 -C obj_dir -f Vtop.mk
+	$(MAKE) -j 4 -C obj_dir -f ../Makefile_obj
+
+	@echo
+	@echo "-- RUN ---------------------"
+	@mkdir -p logs
+	obj_dir/Vtop +trace
+
+	@echo
+	@echo "-- COVERAGE ----------------"
+	$(VERILATOR_COVERAGE) --annotate logs/annotated logs/coverage.dat
+
+	@echo
+	@echo "-- DONE --------------------"
+	@echo "To see waveforms, open vlt_dump.vcd in a waveform viewer"
+	@echo
+
+
+######################################################################
+# Other targets
+
+show-config:
+	$(VERILATOR) -V
+
+maintainer-copy::
+clean mostlyclean distclean maintainer-clean::
+	-rm -rf obj_dir logs *.log *.dmp *.vpd coverage.dat core
@@ -0,0 +1,55 @@
+# -*- Makefile -*-
+#######################################################################
+#
+# DESCRIPTION: Verilator Example: Makefile for inside object directory
+#
+# This is executed in the object directory, and called by ../Makefile
+#
+# Copyright 2003-2017 by Wilson Snyder. This program is free software; you can
+# redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+#
+#######################################################################
+
+default: Vtop
+
+# Include the rules made by Verilator
+include Vtop.mk
+
+#######################################################################
+# Compile flags
+
+# Override some default compile flags
+CPPFLAGS += -MMD -MP
+CPPFLAGS += -DVL_DEBUG=1
+# Turn on some more flags (when configured appropriately)
+# For testing inside Verilator, "configure --enable-ccwarn" will do this
+# automatically; otherwise you may want this unconditionally enabled
+ifeq ($(CFG_WITH_CCWARN),yes)	# Local... Else don't burden users
+USER_CPPFLAGS_WALL += -W -Werror -Wall
+endif
+
+# See the benchmarking section of bin/verilator.
+# Support class optimizations.  This includes the tracing and symbol table.
+# SystemC takes minutes to optimize, thus it is off by default.
+OPT_SLOW =
+# Fast path optimizations.  Most time is spent in these classes.
+OPT_FAST = -O2 -fstrict-aliasing
+#OPT_FAST = -O
+#OPT_FAST =
+
+#######################################################################
+# Linking final exe -- presumes have a sim_main.cpp
+
+# Special compile rule
+sim_main.o: sim_main.cpp $(VM_PREFIX).h
+
+######################################################################
+######################################################################
+# Automatically understand dependencies
+
+DEPS := $(wildcard *.d)
+ifneq ($(DEPS),)
+include $(DEPS)
+endif
@@ -0,0 +1,2 @@
+// This file typically lists flags required by a large project, e.g. include directories
+librescan +libext+.v+.sv+.vh+.svh -y .
@@ -0,0 +1,119 @@
+// DESCRIPTION: Verilator: Verilog example module
+//
+// This file ONLY is placed into the Public Domain, for any use,
+// without warranty, 2017 by Wilson Snyder.
+//======================================================================
+
+// Include common routines
+#include <verilated.h>
+
+#include <sys/stat.h>  // mkdir
+
+// Include model header, generated from Verilating "top.v"
+#include "Vtop.h"
+
+// If "verilator --trace" is used, include the tracing class
+#if VM_TRACE
+# include <verilated_vcd_c.h>
+#endif
+
+// Current simulation time (64-bit unsigned)
+vluint64_t main_time = 0;
+// Called by $time in Verilog
+double sc_time_stamp () {
+    return main_time; // Note does conversion to real, to match SystemC
+}
+
+int main(int argc, char** argv, char** env) {
+    // This is a more complicated example, please also see the simpler examples/hello_world_c.
+
+    // Prevent unused variable warnings
+    if (0 && argc && argv && env) {}
+    // Pass arguments so Verilated code can see them, e.g. $value$plusargs
+    Verilated::commandArgs(argc, argv);
+
+    // Set debug level, 0 is off, 9 is highest presently used
+    Verilated::debug(0);
+
+    // Randomization reset policy
+    Verilated::randReset(2);
+
+    // Construct the Verilated model, from Vtop.h generated from Verilating "top.v"
+    Vtop* top = new Vtop; // Or use a const unique_ptr, or the VL_UNIQUE_PTR wrapper
+
+#if VM_TRACE
+    // If verilator was invoked with --trace argument,
+    // and if at run time passed the +trace argument, turn on tracing
+    VerilatedVcdC* tfp = NULL;
+    const char* flag = Verilated::commandArgsPlusMatch("trace");
+    if (flag && 0==strcmp(flag, "+trace")) {
+        Verilated::traceEverOn(true);  // Verilator must compute traced signals
+        VL_PRINTF("Enabling waves into logs/vlt_dump.vcd...\n");
+        tfp = new VerilatedVcdC;
+        top->trace(tfp, 99);  // Trace 99 levels of hierarchy
+        mkdir("logs", 0777);
+        tfp->open("logs/vlt_dump.vcd");  // Open the dump file
+    }
+#endif
+
+    // Set some inputs
+    top->reset_l = !0;
+    top->fastclk = 0;
+    top->clk = 0;
+    top->in_small = 1;
+    top->in_quad = 0x1234;
+    top->in_wide[0] = 0x11111111;
+    top->in_wide[1] = 0x22222222;
+    top->in_wide[2] = 0x3;
+
+    // Simulate until $finish
+    while (!Verilated::gotFinish()) {
+        main_time++;  // Time passes...
+
+        // Toggle clocks and such
+        top->fastclk = !top->fastclk;
+        if ((main_time % 10) == 3) {
+            top->clk = 1;
+        }
+        if ((main_time % 10) == 8) {
+            top->clk = 0;
+        }
+        if (main_time > 1 && main_time < 10) {
+            top->reset_l = !1;  // Assert reset
+        } else {
+            top->reset_l = !0;  // Deassert reset
+        }
+
+        // Assign some other inputs
+        top->in_quad += 0x12;
+
+        // Evaluate model
+        top->eval();
+
+        // Read outputs
+        VL_PRINTF ("[%" VL_PRI64 "d] clk=%x rstl=%x iquad=%" VL_PRI64 "x"
+                   " -> oquad=%" VL_PRI64"x owide=%x_%08x_%08x\n",
+                   main_time, top->clk, top->reset_l, top->in_quad,
+                   top->out_quad, top->out_wide[2], top->out_wide[1], top->out_wide[0]);
+    }
+
+    // Final model cleanup
+    top->final();
+
+    // Close trace if opened
+#if VM_TRACE
+    if (tfp) { tfp->close(); }
+#endif
+
+    //  Coverage analysis (since test passed)
+#if VM_COVERAGE
+    mkdir("logs", 0777);
+    VerilatedCov::write("logs/coverage.dat");
+#endif
+
+    // Destroy model
+    delete top; top = NULL;
+
+    // Fin
+    exit(0);
+}
@@ -0,0 +1,58 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed into the Public Domain, for any use,
+// without warranty, 2003 by Wilson Snyder.
+// ======================================================================
+
+module sub
+  (
+   input clk,
+   input fastclk,
+   input reset_l
+   );
+
+   // Example counter/flop
+   reg [31:0] count_f;
+   always_ff @ (posedge fastclk) begin
+      if (!reset_l) begin
+         /*AUTORESET*/
+         // Beginning of autoreset for uninitialized flops
+         count_f <= 32'h0;
+         // End of automatics
+      end
+      else begin
+         count_f <= count_f + 1;
+      end
+   end
+
+   // Another example flop
+   reg [31:0] count_c;
+   always_ff @ (posedge clk) begin
+      if (!reset_l) begin
+         /*AUTORESET*/
+         // Beginning of autoreset for uninitialized flops
+         count_c <= 32'h0;
+         // End of automatics
+      end
+      else begin
+         count_c <= count_c + 1;
+         if (count_c >= 3) begin
+            $display("[%0t] fastclk is %0d times faster than clk\n",
+                     $time, count_f/count_c);
+            // This write is a magic value the Makefile uses to make sure the
+            // test completes successfully.
+            $write("*-* All Finished *-*\n");
+            $finish;
+         end
+      end
+   end
+
+   // An example assertion
+   always_ff @ (posedge clk) begin
+      AssertionExample: assert (!reset_l || count_c<100);
+   end
+
+   // And example coverage analysis
+   cover property (@(posedge clk) count_c==3);
+
+endmodule
@@ -0,0 +1,42 @@
+// DESCRIPTION: Verilator: Verilog example module
+//
+// This file ONLY is placed into the Public Domain, for any use,
+// without warranty, 2003 by Wilson Snyder.
+// ======================================================================
+
+// This is intended to be a complex example of several features, please also
+// see the simpler examples/hello_world_c.
+
+module top
+  (
+   // Declare some signals so we can see how I/O works
+   input         clk,
+   input         fastclk,
+   input         reset_l,
+
+   output [1:0]  out_small,
+   output [39:0] out_quad,
+   output [69:0] out_wide,
+   input [1:0]   in_small,
+   input [39:0]  in_quad,
+   input [69:0]  in_wide
+   );
+
+   // Connect up the outputs, using some trivial logic
+   wire [1:0]    out_small = ~reset_l ? '0 : (in_small + 2'b1);
+   wire [39:0]   out_quad  = ~reset_l ? '0 : (in_quad + 40'b1);
+   wire [69:0]   out_wide  = ~reset_l ? '0 : (in_wide + 70'b1);
+
+   // And an example sub module. The submodule will print stuff.
+   sub sub (/*AUTOINST*/
+            // Inputs
+            .clk                        (clk),
+            .fastclk                    (fastclk),
+            .reset_l                    (reset_l));
+
+   // Print some stuff as an example
+   initial begin
+      $display("[%0t] Model running...\n", $time);
+   end
+
+endmodule
@@ -0,0 +1,6 @@
+*.dmp
+*.log
+*.csrc
+*.vcd
+obj_*
+logs
@@ -0,0 +1,109 @@
+######################################################################
+#
+# DESCRIPTION: Verilator Example: Small Makefile
+#
+# This calls the object directory makefile.  That allows the objects to
+# be placed in the "current directory" which simplifies the Makefile.
+#
+# Copyright 2003-2017 by Wilson Snyder. This program is free software; you can
+# redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+#
+######################################################################
+# Check for sanity to avoid later confusion
+
+ifneq ($(words $(CURDIR)),1)
+ $(error Unsupported: GNU Make cannot build in directories containing spaces, build elsewhere: '$(CURDIR)')
+endif
+
+######################################################################
+# Set up variables
+
+# If $VERILATOR_ROOT isn't in the enviornment, we assume it is part of a
+# package inatall, and verilator is in your path. Otherwise find the
+# binary relative to $VERILATOR_ROOT (such as when inside the git sources).
+ifeq ($(VERILATOR_ROOT),)
+VERILATOR = verilator
+VERILATOR_COVERAGE = verilator_coverage
+else
+export VERILATOR_ROOT
+VERILATOR = $(VERILATOR_ROOT)/bin/verilator
+VERILATOR_COVERAGE = $(VERILATOR_ROOT)/bin/verilator_coverage
+endif
+
+VERILATOR_FLAGS =
+# Generate SystemC in executable form
+VERILATOR_FLAGS += -sc --exe
+# Generate makefile dependencies (not shown as complicates the Makefile)
+#VERILATOR_FLAGS += -MMD
+# Optimize
+VERILATOR_FLAGS += -O2 -x-assign 0
+# Warn abount lint issues; may not want this on less solid designs
+VERILATOR_FLAGS += -Wall
+# Make waveforms
+VERILATOR_FLAGS += --trace
+# Check SystemVerilog assertions
+VERILATOR_FLAGS += --assert
+# Generate coverage analysis
+VERILATOR_FLAGS += --coverage
+# Run Verilator in debug mode
+#VERILATOR_FLAGS += --debug
+# Add this trace to get a backtrace in gdb
+#VERILATOR_FLAGS += --gdbbt
+
+# Check if SC exists via a verilator call (empty if not)
+SYSTEMC_EXISTS := $(shell $(VERILATOR) --getenv SYSTEMC_INCLUDE)
+
+######################################################################
+
+ifneq ($(SYSTEMC_EXISTS),)
+default: run
+else
+default: nosc
+endif
+
+run:
+	@echo
+	@echo "-- Verilator tracing example"
+
+	@echo
+	@echo "-- VERILATE ----------------"
+	$(VERILATOR) $(VERILATOR_FLAGS) -f input.vc top.v sc_main.cpp
+
+	@echo
+	@echo "-- COMPILE ----------------="
+# To compile, we can either just do what Verilator asks,
+# or call a submakefile where we can override the rules ourselves
+#	$(MAKE) -j 4 -C obj_dir -f Vtop.mk
+	$(MAKE) -j 4 -C obj_dir -f ../Makefile_obj
+
+	@echo
+	@echo "-- RUN ---------------------"
+	@mkdir -p logs
+	obj_dir/Vtop +trace
+
+	@echo
+	@echo "-- COVERAGE ----------------"
+	$(VERILATOR_COVERAGE) --annotate logs/annotated logs/coverage.dat
+
+	@echo
+	@echo "-- DONE --------------------"
+	@echo "To see waveforms, open vlt_dump.vcd in a waveform viewer"
+	@echo
+
+######################################################################
+# Other targets
+
+nosc:
+	@echo
+	@echo "%Skip: SYSTEMC_INCLUDE not in environment"
+	@echo "(If you have SystemC see the README, and rebuild Verilator)"
+	@echo
+
+show-config:
+	$(VERILATOR) -V
+
+maintainer-copy::
+clean mostlyclean distclean maintainer-clean::
+	-rm -rf obj_dir logs *.log *.dmp *.vpd coverage.dat core
@@ -0,0 +1,63 @@
+# -*- Makefile -*-
+#######################################################################
+#
+# DESCRIPTION: Verilator Example: Makefile for inside object directory
+#
+# This is executed in the object directory, and called by ../Makefile
+#
+# Copyright 2003-2017 by Wilson Snyder. This program is free software; you can
+# redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+#
+#######################################################################
+
+default: Vtop
+
+# Include the rules made by Verilator
+include Vtop.mk
+
+#######################################################################
+# Compile flags
+
+# Override some default compile flags
+CPPFLAGS += -MMD -MP
+CPPFLAGS += -DVL_DEBUG=1
+# SystemC isn't too clean
+CPPFLAGS += -Wno-deprecated
+# Turn on some more flags (when configured appropriately)
+# For testing inside Verilator, "configure --enable-ccwarn" will do this
+# automatically; otherwise you may want this unconditionally enabled
+ifeq ($(CFG_WITH_CCWARN),yes)	# Local... Else don't burden users
+USER_CPPFLAGS_WALL += -W -Werror -Wall
+endif
+
+# If you build your own rules from scratch, note you need to include
+# SystemC as follows (Vtop.mk file includes verilated.mk with these
+# already).
+# CPPFLAGS += $(SYSTEMC_CXX_FLAGS) -I$(SYSTEMC_INCLUDE)
+# LDFLAGS  += $(SYSTEMC_CXX_FLAGS) -L$(SYSTEMC_LIBDIR)
+
+# See the benchmarking section of bin/verilator.
+# Support class optimizations.  This includes the tracing and symbol table.
+# SystemC takes minutes to optimize, thus it is off by default.
+OPT_SLOW =
+# Fast path optimizations.  Most time is spent in these classes.
+OPT_FAST = -O2 -fstrict-aliasing
+#OPT_FAST = -O
+#OPT_FAST =
+
+#######################################################################
+# Linking final exe -- presumes have a sim_main.cpp
+
+# Special compile rule
+sim_main.o: sim_main.cpp $(VM_PREFIX).h
+
+######################################################################
+######################################################################
+# Automatically understand dependencies
+
+DEPS := $(wildcard *.d)
+ifneq ($(DEPS),)
+include $(DEPS)
+endif
@@ -0,0 +1,2 @@
+// This file typically lists flags required by a large project, e.g. include directories
+librescan +libext+.v+.sv+.vh+.svh -y .
@@ -0,0 +1,141 @@
+// -*- SystemC -*-
+// DESCRIPTION: Verilator Example: Top level main for invoking SystemC model
+//
+// This file ONLY is placed into the Public Domain, for any use,
+// without warranty, 2017 by Wilson Snyder.
+//======================================================================
+
+// SystemC global header
+#include <systemc.h>
+
+// Include common routines
+#include <verilated.h>
+#if VM_TRACE
+#include <verilated_vcd_sc.h>
+#endif
+
+#include <sys/stat.h>  // mkdir
+
+// Include model header, generated from Verilating "top.v"
+#include "Vtop.h"
+
+int sc_main(int argc, char* argv[]) {
+    // This is a more complicated example, please also see the simpler examples/hello_world_c.
+
+    // Prevent unused variable warnings
+    if (0 && argc && argv) {}
+    // Pass arguments so Verilated code can see them, e.g. $value$plusargs
+    Verilated::commandArgs(argc, argv);
+
+    // Set debug level, 0 is off, 9 is highest presently used
+    Verilated::debug(0);
+
+    // Randomization reset policy
+    Verilated::randReset(2);
+
+    // General logfile
+    ios::sync_with_stdio();
+
+    // Defaults time
+#if (SYSTEMC_VERSION>20011000)
+#else
+    sc_time dut(1.0, sc_ns);
+    sc_set_default_time_unit(dut);
+#endif
+
+    // Define clocks
+#if (SYSTEMC_VERSION>=20070314)
+    sc_clock clk     ("clk",    10,SC_NS, 0.5, 3,SC_NS, true);
+    sc_clock fastclk ("fastclk", 2,SC_NS, 0.5, 2,SC_NS, true);
+#else
+    sc_clock clk     ("clk",    10, 0.5, 3, true);
+    sc_clock fastclk ("fastclk", 2, 0.5, 2, true);
+#endif
+
+    // Define interconnect
+    sc_signal<bool> reset_l;
+    sc_signal<vluint32_t> in_small;
+    sc_signal<vluint64_t> in_quad;
+    sc_signal<sc_bv<70> > in_wide;
+    sc_signal<vluint32_t> out_small;
+    sc_signal<vluint64_t> out_quad;
+    sc_signal<sc_bv<70> > out_wide;
+
+    // Construct the Verilated model, from inside Vtop.h
+    Vtop* top = new Vtop("top");
+    // Attach signals to the model
+    top->clk       (clk);
+    top->fastclk   (fastclk);
+    top->reset_l   (reset_l);
+    top->in_small  (in_small);
+    top->in_quad   (in_quad);
+    top->in_wide   (in_wide);
+    top->out_small (out_small);
+    top->out_quad  (out_quad);
+    top->out_wide  (out_wide);
+
+#if VM_TRACE
+    // Before any evaluation, need to know to calculate those signals only used for tracing
+    Verilated::traceEverOn(true);
+#endif
+
+    // You must do one evaluation before enabling waves, in order to allow
+    // SystemC to interconnect everything for testing.
+#if (SYSTEMC_VERSION>=20070314)
+    sc_start(1,SC_NS);
+#else
+    sc_start(1);
+#endif
+
+#if VM_TRACE
+    // If verilator was invoked with --trace argument,
+    // and if at run time passed the +trace argument, turn on tracing
+    VerilatedVcdSc* tfp = NULL;
+    const char* flag = Verilated::commandArgsPlusMatch("trace");
+    if (flag && 0==strcmp(flag, "+trace")) {
+        cout << "Enabling waves into logs/vlt_dump.vcd...\n";
+        VerilatedVcdSc* tfp = new VerilatedVcdSc;
+        top->trace (tfp, 99);
+        mkdir("logs", 0777);
+        tfp->open ("logs/vlt_dump.vcd");
+    }
+#endif
+
+    // Simulate until $finish
+    while (!Verilated::gotFinish()) {
+#if VM_TRACE
+        // Flush the wave files each cycle so we can immediately see the output
+        // Don't do this in "real" programs, do it in an abort() handler instead
+        if (tfp) tfp->flush();
+        // Apply inputs
+        if (VL_TIME_Q() > 1 && VL_TIME_Q() < 10) {
+            reset_l = !1;       // Assert reset
+        } else if (VL_TIME_Q() > 1) {
+            reset_l = !0;       // Deassert reset
+        }
+#endif
+        // Simulate 1ns
+#if (SYSTEMC_VERSION>=20070314)
+        sc_start(1,SC_NS);
+#else
+        sc_start(1);
+#endif
+    }
+
+    //  Close Waves
+#if VM_TRACE
+    if (tfp) tfp->close();
+#endif
+
+    // Final model cleanup
+    top->final();
+
+    //  Coverage analysis (since test passed)
+#if VM_COVERAGE
+    mkdir("logs", 0777);
+    VerilatedCov::write("logs/coverage.dat");
+#endif
+
+    // Fin
+    return 0;
+}
@@ -0,0 +1,58 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed into the Public Domain, for any use,
+// without warranty, 2003 by Wilson Snyder.
+// ======================================================================
+
+module sub
+  (
+   input clk,
+   input fastclk,
+   input reset_l
+   );
+
+   // Example counter/flop
+   reg [31:0] count_f;
+   always_ff @ (posedge fastclk) begin
+      if (!reset_l) begin
+         /*AUTORESET*/
+         // Beginning of autoreset for uninitialized flops
+         count_f <= 32'h0;
+         // End of automatics
+      end
+      else begin
+         count_f <= count_f + 1;
+      end
+   end
+
+   // Another example flop
+   reg [31:0] count_c;
+   always_ff @ (posedge clk) begin
+      if (!reset_l) begin
+         /*AUTORESET*/
+         // Beginning of autoreset for uninitialized flops
+         count_c <= 32'h0;
+         // End of automatics
+      end
+      else begin
+         count_c <= count_c + 1;
+         if (count_c >= 3) begin
+            $display("[%0t] fastclk is %0d times faster than clk\n",
+                     $time, count_f/count_c);
+            // This write is a magic value the Makefile uses to make sure the
+            // test completes successfully.
+            $write("*-* All Finished *-*\n");
+            $finish;
+         end
+      end
+   end
+
+   // An example assertion
+   always_ff @ (posedge clk) begin
+      AssertionExample: assert (!reset_l || count_c<100);
+   end
+
+   // And example coverage analysis
+   cover property (@(posedge clk) count_c==3);
+
+endmodule
@@ -0,0 +1,42 @@
+// DESCRIPTION: Verilator: Verilog example module
+//
+// This file ONLY is placed into the Public Domain, for any use,
+// without warranty, 2003 by Wilson Snyder.
+// ======================================================================
+
+// This is intended to be a complex example of several features, please also
+// see the simpler examples/hello_world_c.
+
+module top
+  (
+   // Declare some signals so we can see how I/O works
+   input         clk,
+   input         fastclk,
+   input         reset_l,
+
+   output [1:0]  out_small,
+   output [39:0] out_quad,
+   output [69:0] out_wide,
+   input [1:0]   in_small,
+   input [39:0]  in_quad,
+   input [69:0]  in_wide
+   );
+
+   // Connect up the outputs, using some trivial logic
+   wire [1:0]    out_small = ~reset_l ? '0 : (in_small + 2'b1);
+   wire [39:0]   out_quad  = ~reset_l ? '0 : (in_quad + 40'b1);
+   wire [69:0]   out_wide  = ~reset_l ? '0 : (in_wide + 70'b1);
+
+   // And an example sub module. The submodule will print stuff.
+   sub sub (/*AUTOINST*/
+            // Inputs
+            .clk                        (clk),
+            .fastclk                    (fastclk),
+            .reset_l                    (reset_l));
+
+   // Print some stuff as an example
+   initial begin
+      $display("[%0t] Model running...\n", $time);
+   end
+
+endmodule
@@ -2,7 +2,7 @@
 ######################################################################
 # DESCRIPTION: Makefile commands for all verilated target files
 #
-# Copyright 2003-2015 by Wilson Snyder. Verilator is free software; you can
+# Copyright 2003-2017 by Wilson Snyder. Verilator 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.
 ######################################################################
@@ -16,13 +16,18 @@ RANLIB = ranlib
 CFG_WITH_CCWARN = @CFG_WITH_CCWARN@
 CFG_WITH_LONGTESTS = @CFG_WITH_LONGTESTS@

+# Select newest language
+CFG_CXXFLAGS_STD_NEWEST = @CFG_CXXFLAGS_STD_NEWEST@
+# Select oldest language (for Verilator internal testing only)
+CFG_CXXFLAGS_STD_OLDEST = @CFG_CXXFLAGS_STD_OLDEST@
 # Compiler flags to use to turn off unused and generated code warnings, such as -Wno-div-by-zero
 CFG_CXXFLAGS_NO_UNUSED = @CFG_CXXFLAGS_NO_UNUSED@
+# Compiler flags that turn on extra warnings
+CFG_CXXFLAGS_WEXTRA = @CFG_CXXFLAGS_WEXTRA@

 ######################################################################
 # Programs

-SP_PREPROC	= sp_preproc
 SP_INCLUDER	= $(VERILATOR_INCLUDER)
 VERILATOR_COVERAGE = $(PERL) $(VERILATOR_ROOT)/bin/verilator_coverage
 VERILATOR_INCLUDER = $(PERL) $(VERILATOR_ROOT)/bin/verilator_includer
@@ -43,13 +48,13 @@ VK_CPPFLAGS_ALWAYS += \
 		-I$(VERILATOR_ROOT)/include \
 		-I$(VERILATOR_ROOT)/include/vltstd \
 		-DVL_PRINTF=printf \
-		-DVM_TRACE=$(VM_TRACE) \
 		-DVM_COVERAGE=$(VM_COVERAGE) \
+		-DVM_SC=$(VM_SC) \
+		-DVM_TRACE=$(VM_TRACE) \
 		$(CFG_CXXFLAGS_NO_UNUSED) \

 ifeq ($(CFG_WITH_CCWARN),yes)	# Local... Else don't burden users
-VK_CPPFLAGS_WALL += -Wall \
-		-Werror
+VK_CPPFLAGS_WALL += -Wall $(CFG_CXXFLAGS_WEXTRA) -Werror
 endif

 CPPFLAGS += -I. $(VK_CPPFLAGS_WALL) $(VK_CPPFLAGS_ALWAYS)
@@ -92,9 +97,9 @@ VM_CLASSES += $(VM_CLASSES_FAST) $(VM_CLASSES_SLOW)
 VM_SUPPORT += $(VM_SUPPORT_FAST) $(VM_SUPPORT_SLOW)

 #######################################################################
-##### SystemC or SystemPerl builds
+##### SystemC builds

-ifeq ($(VM_SP_OR_SC),1)
+ifeq ($(VM_SC),1)
  CPPFLAGS += $(SYSTEMC_CXX_FLAGS) -I$(SYSTEMC_INCLUDE)
  LDFLAGS  += $(SYSTEMC_CXX_FLAGS) -L$(SYSTEMC_LIBDIR)
  SC_LIBS   = -lsystemc
@@ -105,37 +110,24 @@ ifeq ($(VM_SP_OR_SC),1)
 endif

 #######################################################################
-##### SystemPerl builds
+##### Threaded builds

-ifeq ($(VM_SP),1)
-  CPPFLAGS += -I$(SYSTEMPERL_INCLUDE) -DSYSTEMPERL
-  VPATH    +=   $(SYSTEMPERL_INCLUDE)
-  LIBS   += -lm -lstdc++
-
-  VK_CLASSES_SP = $(addsuffix .sp, $(VM_CLASSES))
-
-  # This rule is called manually by the upper level makefile
-  preproc:
-	 @echo "      SP Preprocess" $(basename $(VM_CLASSES)) ...
-	 $(SP_PREPROC) -M sp_preproc.d --tree $(VM_PREFIX).sp_tree \
-		--preproc $(VK_CLASSES_SP)
-else
-  preproc:
+ifneq ($(VM_THREADS),0)
+ ifneq ($(VM_THREADS),)
+  # Need C++11 at least, so always default to newest
+  CPPFLAGS += -DVL_THREADED $(CFG_CXXFLAGS_STD_NEWEST)
+ endif
 endif

 #######################################################################
-##### SystemC w/o SystemPerl builds
+##### Stub

-ifeq ($(VM_SC),1)
-  LIBS   += -lm -lstdc++
-endif
+preproc:

 #######################################################################
 ##### C/H builds

-ifeq ($(VM_PCLI),1)
-  LIBS   += -lm -lstdc++
-endif
+LIBS   += -lm -lstdc++

 #######################################################################
 # Overall Objects Linking
@@ -171,16 +163,24 @@ $(VM_PREFIX)__ALL.a: $(VK_OBJS)
 ######################################################################
 ### Compile rules

-#Default rule embedded in make:  (Not defined so user makefiles can override it)
-#.cpp.o:
-#	$(CXX) $(CXXFLAGS) $(CPPFLAGS) -c -o $@ $<
-
+ifneq ($(VM_DEFAULT_RULES),0)
 $(VM_PREFIX)__ALLsup.o: $(VM_PREFIX)__ALLsup.cpp
 	$(OBJCACHE) $(CXX) $(CXXFLAGS) $(CPPFLAGS) $(OPT_SLOW) -c -o $@ $<

 $(VM_PREFIX)__ALLcls.o: $(VM_PREFIX)__ALLcls.cpp
 	$(OBJCACHE) $(CXX) $(CXXFLAGS) $(CPPFLAGS) $(OPT_FAST) -c -o $@ $<

+$(VM_PREFIX)%__Slow.o: $(VM_PREFIX)%__Slow.cpp
+	$(OBJCACHE) $(CXX) $(CXXFLAGS) $(CPPFLAGS) $(OPT_SLOW) -c -o $@ $<
+
+$(VM_PREFIX)%.o: $(VM_PREFIX)%.cpp
+	$(OBJCACHE) $(CXX) $(CXXFLAGS) $(CPPFLAGS) $(OPT_FAST) -c -o $@ $<
+endif
+
+#Default rule embedded in make:
+#.cpp.o:
+#	$(CXX) $(CXXFLAGS) $(CPPFLAGS) -c -o $@ $<
+
 ######################################################################
 ### Debugging

@@ -4,7 +4,7 @@
 //
 //*************************************************************************
 //
-// Copyright 2003-2015 by Wilson Snyder. This program is free software; you can
+// Copyright 2003-2017 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.
@@ -1,7 +1,7 @@
 // -*- mode: C++; c-file-style: "cc-mode" -*-
 //*************************************************************************
 //
-// Copyright 2003-2015 by Wilson Snyder. This program is free software; you can
+// Copyright 2003-2017 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.
@@ -3,7 +3,7 @@
 //
 // THIS MODULE IS PUBLICLY LICENSED
 //
-// Copyright 2001-2015 by Wilson Snyder.  This program is free software;
+// Copyright 2001-2017 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.
 //
@@ -50,7 +50,7 @@ public:  // But only local to this file
    // CONSTRUCTORS
    // Derived classes should call zero() in their constructor
    VerilatedCovImpItem() {
-	for (int i=0; i<MAX_KEYS; i++) {
+	for (int i=0; i<MAX_KEYS; ++i) {
 	    m_keys[i]=KEY_UNDEF;
 	    m_vals[i]=0;
 	}
@@ -72,6 +72,7 @@ private:
    T*	m_countp;	///< Count value
 public:
    // METHODS
+    // cppcheck-suppress truncLongCastReturn
    virtual vluint64_t count() const { return *m_countp; }
    virtual void zero() const { *m_countp = 0; }
    // CONSTRUCTORS
@@ -89,19 +90,20 @@ public:
 class VerilatedCovImp : VerilatedCovImpBase {
 private:
    // TYPES
-    typedef map<string,int> ValueIndexMap;
-    typedef map<int,string> IndexValueMap;
-    typedef deque<VerilatedCovImpItem*> ItemList;
+    typedef std::map<std::string,int> ValueIndexMap;
+    typedef std::map<int,std::string> IndexValueMap;
+    typedef std::deque<VerilatedCovImpItem*> ItemList;

 private:
    // MEMBERS
-    ValueIndexMap	m_valueIndexes;		///< For each key/value a unique arbitrary index value
-    IndexValueMap	m_indexValues;		///< For each key/value a unique arbitrary index value
-    ItemList		m_items;		///< List of all items
+    VerilatedMutex	m_mutex;  ///< Protects all members, when VL_THREADED. Wrapper deals with setting it.
+    ValueIndexMap       m_valueIndexes VL_GUARDED_BY(m_mutex);  ///< For each key/value a unique arbitrary index value
+    IndexValueMap       m_indexValues VL_GUARDED_BY(m_mutex);  ///< For each key/value a unique arbitrary index value
+    ItemList            m_items VL_GUARDED_BY(m_mutex);  ///< List of all items

-    VerilatedCovImpItem*	m_insertp;	///< Item about to insert
-    const char*		m_insertFilenamep;	///< Filename about to insert
-    int			m_insertLineno;		///< Line number about to insert
+    VerilatedCovImpItem* m_insertp VL_GUARDED_BY(m_mutex);  ///< Item about to insert
+    const char*         m_insertFilenamep VL_GUARDED_BY(m_mutex);  ///< Filename about to insert
+    int                 m_insertLineno VL_GUARDED_BY(m_mutex);  ///< Line number about to insert

    // CONSTRUCTORS
    VerilatedCovImp() {
@@ -109,28 +111,29 @@ private:
 	m_insertFilenamep = NULL;
 	m_insertLineno = 0;
    }
+    VL_UNCOPYABLE(VerilatedCovImp);
 public:
-    ~VerilatedCovImp() { clear(); }
-    static VerilatedCovImp& imp() {
+    ~VerilatedCovImp() { clearGuts(); }
+    static VerilatedCovImp& imp() VL_MT_SAFE {
 	static VerilatedCovImp s_singleton;
 	return s_singleton;
    }

 private:
    // PRIVATE METHODS
-    int valueIndex(const string& value) {
+    int valueIndex(const std::string& value) VL_REQUIRES(m_mutex) {
 	static int nextIndex = KEY_UNDEF+1;
 	ValueIndexMap::iterator iter = m_valueIndexes.find(value);
 	if (iter != m_valueIndexes.end()) return iter->second;
 	nextIndex++;  assert(nextIndex>0);
-	m_valueIndexes.insert(make_pair(value, nextIndex));
-	m_indexValues.insert(make_pair(nextIndex, value));
+	m_valueIndexes.insert(std::make_pair(value, nextIndex));
+	m_indexValues.insert(std::make_pair(nextIndex, value));
 	return nextIndex;
    }
-    string dequote(const string& text) {
+    static std::string dequote(const std::string& text) VL_PURE {
 	// Quote any special characters
-	string rtn;
-	for (const char* pos = text.c_str(); *pos; pos++) {
+	std::string rtn;
+	for (const char* pos = text.c_str(); *pos; ++pos) {
 	    if (!isprint(*pos) || *pos=='%' || *pos=='"') {
 		char hex[10]; sprintf(hex,"%%%02X",pos[0]);
 		rtn += hex;
@@ -140,7 +143,7 @@ private:
 	}
 	return rtn;
    }
-    bool legalKey(const string& key) {
+    static bool legalKey(const std::string& key) VL_PURE {
 	// Because we compress long keys to a single letter, and
 	// don't want applications to either get confused if they use
 	// a letter differently, nor want them to rely on our compression...
@@ -149,17 +152,17 @@ private:
 	if (key.length()==2 && isdigit(key[1])) return false;
 	return true;
    }
-    string keyValueFormatter (const string& key, const string& value) {
-	string name;
+    static std::string keyValueFormatter(const std::string& key, const std::string& value) VL_PURE {
+	std::string name;
 	if (key.length()==1 && isalpha(key[0])) {
-	    name += string("\001")+key;
+	    name += std::string("\001")+key;
 	} else {
-	    name += string("\001")+dequote(key);
+	    name += std::string("\001")+dequote(key);
 	}
-	name += string("\002")+dequote(value);
+	name += std::string("\002")+dequote(value);
 	return name;
    }
-    string combineHier (const string& old, const string& add) {
+    static std::string combineHier(const std::string& old, const std::string& add) VL_PURE {
 	// (foo.a.x, foo.b.x) => foo.*.x
 	// (foo.a.x, foo.b.y) => foo.*
 	// (foo.a.x, foo.b)   => foo.*
@@ -177,7 +180,7 @@ private:

 	// We used to backup and split on only .'s but it seems better to be verbose
 	// and not assume . is the separator
-	string prefix = string(a,apre-a);
+	std::string prefix = std::string(a,apre-a);

 	// Scan backward to last mismatch
 	const char* apost = a+strlen(a)-1;
@@ -186,41 +189,38 @@ private:
 	       && apost>apre && bpost>bpre) { apost--; bpost--; }

 	// Forward to . so we have a whole word
-	string suffix = *bpost ? string(bpost+1) : "";
+	std::string suffix = *bpost ? std::string(bpost+1) : "";

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

 	//cout << "\nch pre="<<prefix<<"  s="<<suffix<<"\nch a="<<old<<"\nch b="<<add<<"\nch o="<<out<<endl;
 	return out;
    }
-    bool itemMatchesString(VerilatedCovImpItem* itemp, const string& match) {
-	for (int i=0; i<MAX_KEYS; i++) {
+    bool itemMatchesString(VerilatedCovImpItem* itemp, const std::string& match) VL_REQUIRES(m_mutex) {
+	for (int i=0; i<MAX_KEYS; ++i) {
 	    if (itemp->m_keys[i] != KEY_UNDEF) {
 		// We don't compare keys, only values
-		string val = m_indexValues[itemp->m_vals[i]];
-		if (string::npos != val.find(match)) {  // Found
+		std::string val = m_indexValues[itemp->m_vals[i]];
+		if (std::string::npos != val.find(match)) {  // Found
 		    return true;
 		}
 	    }
 	}
 	return false;
    }
-    void selftest() {
+    static void selftest() VL_MT_SAFE {
 	// Little selftest
-	if (combineHier ("a.b.c","a.b.c")	!="a.b.c") vl_fatal(__FILE__,__LINE__,"","%Error: selftest\n");
-	if (combineHier ("a.b.c","a.b")		!="a.b*") vl_fatal(__FILE__,__LINE__,"","%Error: selftest\n");
-	if (combineHier ("a.x.c","a.y.c")	!="a.*.c") vl_fatal(__FILE__,__LINE__,"","%Error: selftest\n");
-	if (combineHier ("a.z.z.z.c","a.b.c")	!="a.*.c") vl_fatal(__FILE__,__LINE__,"","%Error: selftest\n");
-	if (combineHier ("z","a")		!="*") vl_fatal(__FILE__,__LINE__,"","%Error: selftest\n");
-	if (combineHier ("q.a","q.b")		!="q.*") vl_fatal(__FILE__,__LINE__,"","%Error: selftest\n");
-	if (combineHier ("q.za","q.zb")		!="q.z*") vl_fatal(__FILE__,__LINE__,"","%Error: selftest\n");
-	if (combineHier ("1.2.3.a","9.8.7.a")	!="*.a") vl_fatal(__FILE__,__LINE__,"","%Error: selftest\n");
+	if (combineHier ("a.b.c","a.b.c")	!="a.b.c") VL_FATAL_MT(__FILE__,__LINE__,"","%Error: selftest\n");
+	if (combineHier ("a.b.c","a.b")		!="a.b*") VL_FATAL_MT(__FILE__,__LINE__,"","%Error: selftest\n");
+	if (combineHier ("a.x.c","a.y.c")	!="a.*.c") VL_FATAL_MT(__FILE__,__LINE__,"","%Error: selftest\n");
+	if (combineHier ("a.z.z.z.c","a.b.c")	!="a.*.c") VL_FATAL_MT(__FILE__,__LINE__,"","%Error: selftest\n");
+	if (combineHier ("z","a")		!="*") VL_FATAL_MT(__FILE__,__LINE__,"","%Error: selftest\n");
+	if (combineHier ("q.a","q.b")		!="q.*") VL_FATAL_MT(__FILE__,__LINE__,"","%Error: selftest\n");
+	if (combineHier ("q.za","q.zb")		!="q.z*") VL_FATAL_MT(__FILE__,__LINE__,"","%Error: selftest\n");
+	if (combineHier ("1.2.3.a","9.8.7.a")	!="*.a") VL_FATAL_MT(__FILE__,__LINE__,"","%Error: selftest\n");
    }
-
-public:
-    // PUBLIC METHODS
-    void clear() {
-	for (ItemList::iterator it=m_items.begin(); it!=m_items.end(); ++it) {
+    void clearGuts() VL_REQUIRES(m_mutex) {
+	for (ItemList::const_iterator it=m_items.begin(); it!=m_items.end(); ++it) {
 	    VerilatedCovImpItem* itemp = *(it);
 	    delete itemp;
 	}
@@ -228,7 +228,17 @@ public:
 	m_indexValues.clear();
 	m_valueIndexes.clear();
    }
-    void clearNonMatch (const char* matchp) {
+
+public:
+    // PUBLIC METHODS
+    void clear() VL_EXCLUDES(m_mutex) {
+	Verilated::quiesce();
+	VerilatedLockGuard guard(m_mutex);
+	clearGuts();
+    }
+    void clearNonMatch(const char* matchp) VL_EXCLUDES(m_mutex) {
+	Verilated::quiesce();
+	VerilatedLockGuard guard(m_mutex);
 	if (matchp && matchp[0]) {
 	    ItemList newlist;
 	    for (ItemList::iterator it=m_items.begin(); it!=m_items.end(); ++it) {
@@ -242,47 +252,52 @@ public:
 	    m_items = newlist;
 	}
    }
-    void zero() {
-	for (ItemList::iterator it=m_items.begin(); it!=m_items.end(); ++it) {
+    void zero() VL_EXCLUDES(m_mutex) {
+	Verilated::quiesce();
+	VerilatedLockGuard guard(m_mutex);
+	for (ItemList::const_iterator it=m_items.begin(); it!=m_items.end(); ++it) {
 	    (*it)->zero();
 	}
    }

    // We assume there's always call to i/f/p in that order
-    void inserti (VerilatedCovImpItem* itemp) {
+    void inserti (VerilatedCovImpItem* itemp) VL_EXCLUDES(m_mutex) {
+	VerilatedLockGuard guard(m_mutex);
 	assert(!m_insertp);
 	m_insertp = itemp;
    }
-    void insertf (const char* filenamep, int lineno) {
+    void insertf (const char* filenamep, int lineno) VL_EXCLUDES(m_mutex) {
+	VerilatedLockGuard guard(m_mutex);
 	m_insertFilenamep = filenamep;
 	m_insertLineno = lineno;
    }
    void insertp (const char* ckeyps[MAX_KEYS],
-		  const char* valps[MAX_KEYS]) {
+		  const char* valps[MAX_KEYS]) VL_EXCLUDES(m_mutex) {
+	VerilatedLockGuard guard(m_mutex);
 	assert(m_insertp);
 	// First two key/vals are filename
 	ckeyps[0]="filename";	valps[0]=m_insertFilenamep;
-	string linestr = vlCovCvtToStr(m_insertLineno);
+	std::string linestr = vlCovCvtToStr(m_insertLineno);
 	ckeyps[1]="lineno";	valps[1]=linestr.c_str();
 	// Default page if not specified
 	const char* fnstartp = m_insertFilenamep;
 	while (const char* foundp = strchr(fnstartp,'/')) fnstartp=foundp+1;
 	const char* fnendp = fnstartp;
 	while (*fnendp && *fnendp!='.') fnendp++;
-	string page_default = "sp_user/"+string(fnstartp,fnendp-fnstartp);
+	std::string page_default = "sp_user/"+std::string(fnstartp,fnendp-fnstartp);
 	ckeyps[2]="page";	valps[2]=page_default.c_str();

 	// Keys -> strings
-	string keys[MAX_KEYS];
-	for (int i=0; i<MAX_KEYS; i++) {
+	std::string keys[MAX_KEYS];
+	for (int i=0; i<MAX_KEYS; ++i) {
 	    if (ckeyps[i] && ckeyps[i][0]) {
 		keys[i] = ckeyps[i];
 	    }
 	}
 	// Ignore empty keys
-	for (int i=0; i<MAX_KEYS; i++) {
+	for (int i=0; i<MAX_KEYS; ++i) {
 	    if (keys[i]!="") {
-		for (int j=i+1; j<MAX_KEYS; j++) {
+		for (int j=i+1; j<MAX_KEYS; ++j) {
 		    if (keys[i] == keys[j]) {  // Duplicate key.  Keep the last one
 			keys[i] = "";
 			break;
@@ -292,17 +307,17 @@ public:
 	}
 	// Insert the values
 	int addKeynum=0;
-	for (int i=0; i<MAX_KEYS; i++) {
-	    const string key = keys[i];
+	for (int i=0; i<MAX_KEYS; ++i) {
+	    const std::string key = keys[i];
 	    if (keys[i]!="") {
-		const string val = valps[i];
+		const std::string val = valps[i];
 		//cout<<"   "<<__FUNCTION__<<"  "<<key<<" = "<<val<<endl;
 		m_insertp->m_keys[addKeynum] = valueIndex(key);
 		m_insertp->m_vals[addKeynum] = valueIndex(val);
 		addKeynum++;
 		if (!legalKey(key)) {
-		    string msg = "%Error: Coverage keys of one character, or letter+digit are illegal: "+key;
-		    vl_fatal("",0,"",msg.c_str());
+		    std::string msg = "%Error: Coverage keys of one character, or letter+digit are illegal: "+key;
+		    VL_FATAL_MT("",0,"",msg.c_str());
 		}
 	    }
 	}
@@ -311,33 +326,35 @@ public:
 	m_insertp = NULL;
    }

-    void write (const char* filename) {
+    void write(const char* filename) VL_EXCLUDES(m_mutex) {
+	Verilated::quiesce();
+	VerilatedLockGuard guard(m_mutex);
 #ifndef VM_COVERAGE
-	vl_fatal("",0,"","%Error: Called VerilatedCov::write when VM_COVERAGE disabled\n");
+	VL_FATAL_MT("",0,"","%Error: Called VerilatedCov::write when VM_COVERAGE disabled\n");
 #endif
 	selftest();

-	ofstream os (filename);
+	std::ofstream os (filename);
 	if (os.fail()) {
-	    string msg = (string)"%Error: Can't write '"+filename+"'";
-	    vl_fatal("",0,"",msg.c_str());
+	    std::string msg = std::string("%Error: Can't write '")+filename+"'";
+	    VL_FATAL_MT("",0,"",msg.c_str());
 	    return;
 	}
 	os << "# SystemC::Coverage-3\n";

 	// Build list of events; totalize if collapsing hierarchy
-	typedef map<string,pair<string,vluint64_t> >	EventMap;
-	EventMap	eventCounts;
+	typedef std::map<std::string,std::pair<std::string,vluint64_t> > EventMap;
+	EventMap eventCounts;
 	for (ItemList::iterator it=m_items.begin(); it!=m_items.end(); ++it) {
 	    VerilatedCovImpItem* itemp = *(it);
-	    string name;
-	    string hier;
+	    std::string name;
+	    std::string hier;
 	    bool per_instance = false;

-	    for (int i=0; i<MAX_KEYS; i++) {
+	    for (int i=0; i<MAX_KEYS; ++i) {
 		if (itemp->m_keys[i] != KEY_UNDEF) {
-		    string key = VerilatedCovKey::shortKey(m_indexValues[itemp->m_keys[i]]);
-		    string val = m_indexValues[itemp->m_vals[i]];
+		    std::string key = VerilatedCovKey::shortKey(m_indexValues[itemp->m_keys[i]]);
+		    std::string val = m_indexValues[itemp->m_vals[i]];
 		    if (key == VL_CIK_PER_INSTANCE) {
 			if (val != "0") per_instance = true;
 		    }
@@ -362,21 +379,21 @@ public:
 	    // Find or insert the named event
 	    EventMap::iterator cit = eventCounts.find(name);
 	    if (cit != eventCounts.end()) {
-		const string& oldhier = cit->second.first;
+		const std::string& oldhier = cit->second.first;
 		cit->second.second += itemp->count();
 		cit->second.first  = combineHier(oldhier, hier);
 	    } else {
-		eventCounts.insert(make_pair(name, make_pair(hier,itemp->count())));
+		eventCounts.insert(std::make_pair(name, make_pair(hier,itemp->count())));
 	    }
 	}

 	// Output body
-	for (EventMap::iterator it=eventCounts.begin(); it!=eventCounts.end(); ++it) {
-	    os<<"C '"<<dec;
+	for (EventMap::const_iterator it=eventCounts.begin(); it!=eventCounts.end(); ++it) {
+	    os<<"C '"<<std::dec;
 	    os<<it->first;
 	    if (it->second.first != "") os<<keyValueFormatter(VL_CIK_HIER,it->second.first);
 	    os<<"' "<<it->second.second;
-	    os<<endl;
+	    os<<std::endl;
 	}
    }
 };
@@ -384,25 +401,25 @@ public:
 //=============================================================================
 // VerilatedCov

-void VerilatedCov::clear() {
+void VerilatedCov::clear() VL_MT_SAFE {
    VerilatedCovImp::imp().clear();
 }
-void VerilatedCov::clearNonMatch (const char* matchp) {
+void VerilatedCov::clearNonMatch(const char* matchp) VL_MT_SAFE {
    VerilatedCovImp::imp().clearNonMatch(matchp);
 }
-void VerilatedCov::zero() {
+void VerilatedCov::zero() VL_MT_SAFE {
    VerilatedCovImp::imp().zero();
 }
-void VerilatedCov::write (const char* filenamep) {
+void VerilatedCov::write(const char* filenamep) VL_MT_SAFE {
    VerilatedCovImp::imp().write(filenamep);
 }
-void VerilatedCov::_inserti (vluint32_t* itemp) {
+void VerilatedCov::_inserti(vluint32_t* itemp) VL_MT_SAFE {
    VerilatedCovImp::imp().inserti(new VerilatedCoverItemSpec<vluint32_t>(itemp));
 }
-void VerilatedCov::_inserti (vluint64_t* itemp) {
+void VerilatedCov::_inserti(vluint64_t* itemp) VL_MT_SAFE {
    VerilatedCovImp::imp().inserti(new VerilatedCoverItemSpec<vluint64_t>(itemp));
 }
-void VerilatedCov::_insertf (const char* filename, int lineno) {
+void VerilatedCov::_insertf(const char* filename, int lineno) VL_MT_SAFE {
    VerilatedCovImp::imp().insertf(filename,lineno);
 }

@@ -412,7 +429,7 @@ void VerilatedCov::_insertf (const char* filename, int lineno) {
 #define N(n) "",""	// Null argument list
 void VerilatedCov::_insertp (A(0),A(1),A(2),A(3),A(4),A(5),A(6),A(7),A(8),A(9),
 			     A(10),A(11),A(12),A(13),A(14),A(15),A(16),A(17),A(18),A(19),
-			     A(20),A(21),A(22),A(23),A(24),A(25),A(26),A(27),A(28),A(29)) {
+			     A(20),A(21),A(22),A(23),A(24),A(25),A(26),A(27),A(28),A(29)) VL_MT_SAFE {
    const char* keyps[VerilatedCovImpBase::MAX_KEYS]
 	= {NULL,NULL,NULL,	// filename,lineno,page
 	   key0,key1,key2,key3,key4,key5,key6,key7,key8,key9,
@@ -427,22 +444,22 @@ void VerilatedCov::_insertp (A(0),A(1),A(2),A(3),A(4),A(5),A(6),A(7),A(8),A(9),
 }

 // And versions with fewer arguments  (oh for a language with named parameters!)
-void VerilatedCov::_insertp (A(0),A(1),A(2),A(3),A(4),A(5),A(6),A(7),A(8),A(9)) {
+void VerilatedCov::_insertp (A(0),A(1),A(2),A(3),A(4),A(5),A(6),A(7),A(8),A(9)) VL_MT_SAFE {
    _insertp(C(0),C(1),C(2),C(3),C(4),C(5),C(6),C(7),C(8),C(9),
 	     N(10),N(11),N(12),N(13),N(14),N(15),N(16),N(17),N(18),N(19),
 	     N(20),N(21),N(22),N(23),N(24),N(25),N(26),N(27),N(28),N(29));
 }
 void VerilatedCov::_insertp (A(0),A(1),A(2),A(3),A(4),A(5),A(6),A(7),A(8),A(9),
-			     A(10),A(11),A(12),A(13),A(14),A(15),A(16),A(17),A(18),A(19)) {
+			     A(10),A(11),A(12),A(13),A(14),A(15),A(16),A(17),A(18),A(19)) VL_MT_SAFE {
    _insertp(C(0),C(1),C(2),C(3),C(4),C(5),C(6),C(7),C(8),C(9),
 	     C(10),C(11),C(12),C(13),C(14),C(15),C(16),C(17),C(18),C(19),
 	     N(20),N(21),N(22),N(23),N(24),N(25),N(26),N(27),N(28),N(29));
 }
 // Backward compatibility for Verilator
 void VerilatedCov::_insertp (A(0), A(1),  K(2),int val2,  K(3),int val3,
-			     K(4),const string& val4,  A(5),A(6)) {
-    string val2str = vlCovCvtToStr(val2);
-    string val3str = vlCovCvtToStr(val3);
+			     K(4),const std::string& val4,  A(5),A(6)) VL_MT_SAFE {
+    std::string val2str = vlCovCvtToStr(val2);
+    std::string val3str = vlCovCvtToStr(val3);
    _insertp(C(0),C(1),
 	     key2,val2str.c_str(),  key3,val3str.c_str(),  key4, val4.c_str(),
 	     C(5),C(6),N(7),N(8),N(9),
@@ -3,7 +3,7 @@
 //
 // THIS MODULE IS PUBLICLY LICENSED
 //
-// Copyright 2001-2015 by Wilson Snyder.  This program is free software;
+// Copyright 2001-2017 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.
 //
@@ -27,7 +27,6 @@
 #include <iostream>
 #include <sstream>
 #include <string>
-using namespace std;

 //=============================================================================
 /// Conditionally compile coverage code
@@ -60,9 +59,9 @@ using namespace std;
 ///
 ///	vluint32_t m_cases[10];
 ///	constructor {
-///	    for (int i=0; i<10; i++) { m_cases[i]=0; }
+///	    for (int i=0; i<10; ++i) { m_cases[i]=0; }
 ///     }
-///	for (int i=0; i<10; i++) {
+///	for (int i=0; i<10; ++i) {
 ///		VL_COVER_INSERT(&m_cases[i], "comment", "Coverage Case", "i", cvtToNumStr(i));
 ///	}

@@ -74,8 +73,8 @@ using namespace std;
 //=============================================================================
 /// Convert VL_COVER_INSERT value arguments to strings

-template< class T> std::string vlCovCvtToStr (const T& t) {
-    ostringstream os; os<<t; return os.str();
+template< class T> std::string vlCovCvtToStr (const T& t) VL_PURE {
+    std::ostringstream os; os<<t; return os.str();
 }

 //=============================================================================
@@ -83,23 +82,25 @@ template< class T> std::string vlCovCvtToStr (const T& t) {
 ///  Verilator coverage global class
 ////
 /// Global class with methods affecting all coverage data.
+/// All public methods in this class are thread safe.

 class VerilatedCov {
+    VL_UNCOPYABLE(VerilatedCov);
 public:
    // GLOBAL METHODS
    /// Return default filename
-    static const char* defaultFilename() { return "coverage.dat"; }
+    static const char* defaultFilename() VL_PURE { return "coverage.dat"; }
    /// Write all coverage data to a file
-    static void write (const char* filenamep = defaultFilename());
+    static void write (const char* filenamep = defaultFilename()) VL_MT_SAFE;
    /// Insert a coverage item
    /// We accept from 1-30 key/value pairs, all as strings.
    /// Call _insert1, followed by _insert2 and _insert3
    /// Do not call directly; use VL_COVER_INSERT or higher level macros instead
    // _insert1: Remember item pointer with count.  (Not const, as may add zeroing function)
-    static void _inserti (vluint32_t* itemp);
-    static void _inserti (vluint64_t* itemp);
+    static void _inserti (vluint32_t* itemp) VL_MT_SAFE;
+    static void _inserti (vluint64_t* itemp) VL_MT_SAFE;
    // _insert2: Set default filename and line number
-    static void _insertf (const char* filename, int lineno);
+    static void _insertf (const char* filename, int lineno) VL_MT_SAFE;
    // _insert3: Set parameters
    // We could have just the maximum argument version, but this compiles
    // much slower (nearly 2x) than having smaller versions also.  However
@@ -115,17 +116,17 @@ public:
 			  ,A(20),D(21),D(22),D(23),D(24),D(25),D(26),D(27),D(28),D(29));
    // Backward compatibility for Verilator
    static void _insertp (A(0), A(1),  K(2),int val2,  K(3),int val3,
-			  K(4),const string& val4,  A(5),A(6));
+			  K(4),const std::string& val4,  A(5),A(6));

 #undef K
 #undef A
 #undef D
    /// Clear coverage points (and call delete on all items)
-    static void clear();
+    static void clear() VL_MT_SAFE;
    /// Clear items not matching the provided string
-    static void clearNonMatch (const char* matchp);
+    static void clearNonMatch (const char* matchp) VL_MT_SAFE;
    /// Zero coverage points
-    static void zero();
+    static void zero() VL_MT_SAFE;
 };

 #endif // guard
@@ -3,7 +3,7 @@
 //
 // THIS MODULE IS PUBLICLY LICENSED
 //
-// Copyright 2001-2015 by Wilson Snyder.  This program is free software;
+// Copyright 2001-2017 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.
 //
@@ -25,7 +25,6 @@
 #include "verilatedos.h"

 #include <string>
-using namespace std;

 //=============================================================================
 // Data used to edit below file, using vlcovgen
@@ -64,12 +63,6 @@ VLCOVGEN_ITEM("name=>'row2',        short=>'r2', group=>0, default=>undef, ")
 VLCOVGEN_ITEM("name=>'row3',        short=>'r3', group=>0, default=>undef, ")
 VLCOVGEN_ITEM("name=>'weight',      short=>'w',  group=>0, default=>undef, descr=>'For totaling items, weight of this item'")

-//=============================================================================
-//  VerilatedCovKey
-///  Verilator coverage global class
-////
-/// Global class with methods affecting all coverage data.
-
 // VLCOVGEN_CIK_AUTO_EDIT_BEGIN
 #define VL_CIK_COL0 "c0"
 #define VL_CIK_COL0_NAME "C0"
@@ -103,9 +96,14 @@ VLCOVGEN_ITEM("name=>'weight',      short=>'w',  group=>0, default=>undef, descr
 #define VL_CIK_WEIGHT "w"
 // VLCOVGEN_CIK_AUTO_EDIT_END

+//=============================================================================
+// VerilatedCovKey
+/// Verilator coverage global class.
+/// This class is thread safe.
+
 class VerilatedCovKey {
 public:
-    static string shortKey(const string& key) {
+    static std::string shortKey(const std::string& key) VL_PURE {
 	// VLCOVGEN_SHORT_AUTO_EDIT_BEGIN
 	if (key == "col0") return VL_CIK_COL0;
 	if (key == "col0_name") return VL_CIK_COL0_NAME;
@@ -1,7 +1,7 @@
 // -*- mode: C++; c-file-style: "cc-mode" -*-
 //*************************************************************************
 //
-// Copyright 2009-2015 by Wilson Snyder. This program is free software; you can
+// Copyright 2009-2017 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.
@@ -30,7 +30,9 @@

 // On MSVC++ we need svdpi.h to declare exports, not imports
 #define DPI_PROTOTYPES
+#undef XXTERN
 #define XXTERN DPI_EXTERN DPI_DLLESPEC
+#undef EETERN
 #define EETERN DPI_EXTERN DPI_DLLESPEC

 #include "vltstd/svdpi.h"
@@ -40,11 +42,11 @@

 // Not supported yet
 #define _VL_SVDPI_UNIMP() \
-    vl_fatal(__FILE__,__LINE__,"",(string("%%Error: Unsupported DPI function: ")+VL_FUNC).c_str())
+    VL_FATAL_MT(__FILE__,__LINE__,"",(std::string("%%Error: Unsupported DPI function: ")+VL_FUNC).c_str())

 // Function requires a "context" in the import declaration
 #define _VL_SVDPI_CONTEXT_WARN() \
-    VL_PRINTF("%%Warning: DPI C Function called by Verilog DPI import with missing 'context' keyword.\n");
+    VL_PRINTF_MT("%%Warning: DPI C Function called by Verilog DPI import with missing 'context' keyword.\n");

 //======================================================================
 //======================================================================
@@ -58,31 +60,31 @@ const char* svDpiVersion() {
 //======================================================================
 // Bit-select utility functions.

-svBit svGetBitselBit(const svBitVecVal* s, int i) {
-    _VL_SVDPI_UNIMP(); return 0;
+svBit svGetBitselBit(const svBitVecVal* sp, int bit) {
+    return VL_BITISSET_W(sp,bit);
 }
-svLogic svGetBitselLogic(const svLogicVecVal* s, int i) {
+svLogic svGetBitselLogic(const svLogicVecVal* sp, int bit) {
    _VL_SVDPI_UNIMP(); return 0;
 }

-void svPutBitselBit(svBitVecVal* d, int i, svBit s) {
-    _VL_SVDPI_UNIMP();
+void svPutBitselBit(svBitVecVal* dp, int bit, svBit s) {
+    VL_ASSIGNBIT_WI(32, bit, dp, s);
 }
-void svPutBitselLogic(svLogicVecVal* d, int i, svLogic s) {
+void svPutBitselLogic(svLogicVecVal* dp, int bit, svLogic s) {
    _VL_SVDPI_UNIMP();
 }

-void svGetPartselBit(svBitVecVal* d, const svBitVecVal* s, int i, int w) {
+void svGetPartselBit(svBitVecVal* dp, const svBitVecVal* sp, int i, int w) {
    _VL_SVDPI_UNIMP();
 }
-void svGetPartselLogic(svLogicVecVal* d, const svLogicVecVal* s, int i, int w) {
+void svGetPartselLogic(svLogicVecVal* dp, const svLogicVecVal* sp, int i, int w) {
    _VL_SVDPI_UNIMP();
 }

-void svPutPartselBit(svBitVecVal* d, const svBitVecVal s, int i, int w) {
+void svPutPartselBit(svBitVecVal* dp, const svBitVecVal s, int i, int w) {
    _VL_SVDPI_UNIMP();
 }
-void svPutPartselLogic(svLogicVecVal* d, const svLogicVecVal* s, int i, int w) {
+void svPutPartselLogic(svLogicVecVal* dp, const svLogicVecVal* sp, int i, int w) {
    _VL_SVDPI_UNIMP();
 }

@@ -261,13 +263,13 @@ svScope svGetScope() {

 svScope svSetScope(const svScope scope) {
    const VerilatedScope* prevScopep = Verilated::dpiScope();
-    const VerilatedScope* vscopep = (const VerilatedScope*)(scope);
+    const VerilatedScope* vscopep = reinterpret_cast<const VerilatedScope*>(scope);
    Verilated::dpiScope(vscopep);
    return (svScope)prevScopep;
 }

 const char* svGetNameFromScope(const svScope scope) {
-    const VerilatedScope* vscopep = (const VerilatedScope*)(scope);
+    const VerilatedScope* vscopep = reinterpret_cast<const VerilatedScope*>(scope);
    return vscopep->name();
 }

@@ -1,7 +1,7 @@
 // -*- mode: C++; c-file-style: "cc-mode" -*-
 //*************************************************************************
 //
-// Copyright 2003-2015 by Wilson Snyder. This program is free software; you can
+// Copyright 2003-2017 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.
@@ -16,9 +16,9 @@
 /// \file
 /// \brief Verilator: Common include for all Verilated C files that use DPI
 ///
-///	This file is included automatically by Verilator at the top of
-///	all C++ files it generates where DPI is used.  It contains
-///	DPI interface functions required by the Verilated code.
+///     This file is included automatically by Verilator at the top of
+///     all C++ files it generates where DPI is used.  It contains
+///     DPI interface functions required by the Verilated code.
 ///
 /// Code available from: http://www.veripool.org/verilator
 ///
@@ -35,27 +35,27 @@
 // SETTING OPERATORS

 /// Return svBitVecVal from WData
-static inline void VL_SET_W_SVBV(int obits, WDataOutP owp, svBitVecVal* lwp) {
+static inline void VL_SET_W_SVBV(int obits, WDataOutP owp, svBitVecVal* lwp) VL_MT_SAFE {
    int words = VL_WORDS_I(obits);
-    for (int i=0; i<words-1; i++) owp[i]=lwp[i];
+    for (int i=0; i<words-1; ++i) owp[i]=lwp[i];
    owp[words-1] = lwp[words-1] & VL_MASK_I(obits);
 }
-static inline void VL_SET_SVBV_W(int obits, svBitVecVal* owp, WDataInP lwp) {
+static inline void VL_SET_SVBV_W(int obits, svBitVecVal* owp, WDataInP lwp) VL_MT_SAFE {
    int words = VL_WORDS_I(obits);
-    for (int i=0; i<words-1; i++) owp[i]=lwp[i];
+    for (int i=0; i<words-1; ++i) owp[i]=lwp[i];
    owp[words-1] = lwp[words-1] & VL_MASK_I(obits);
 }
-static inline void VL_SET_W_SVLV(int obits, WDataOutP owp, svLogicVecVal* lwp) {
+static inline void VL_SET_W_SVLV(int obits, WDataOutP owp, svLogicVecVal* lwp) VL_MT_SAFE {
    // Note we ignore X/Z in svLogicVecVal
    int words = VL_WORDS_I(obits);
-    for (int i=0; i<words-1; i++) owp[i]=lwp[i].aval;
+    for (int i=0; i<words-1; ++i) owp[i]=lwp[i].aval;
    owp[words-1] = lwp[words-1].aval & VL_MASK_I(obits);
 }
-static inline void VL_SET_SVLV_W(int obits, svLogicVecVal* owp, WDataInP lwp) {
+static inline void VL_SET_SVLV_W(int obits, svLogicVecVal* owp, WDataInP lwp) VL_MT_SAFE {
    // Note we don't create X/Z in svLogicVecVal
    int words = VL_WORDS_I(obits);
-    for (int i=0; i<words; i++) owp[i].bval=0;
-    for (int i=0; i<words-1; i++) owp[i].aval=lwp[i];
+    for (int i=0; i<words; ++i) owp[i].bval=0;
+    for (int i=0; i<words-1; ++i) owp[i].aval=lwp[i];
    owp[words-1].aval = lwp[words-1] & VL_MASK_I(obits);
 }

@@ -1,7 +1,7 @@
 // -*- mode: C++; c-file-style: "cc-mode" -*-
 //*************************************************************************
 //
-// Copyright 2010-2015 by Wilson Snyder. This program is free software; you can
+// Copyright 2010-2017 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.
@@ -16,10 +16,10 @@
 /// \file
 /// \brief Verilator: String include for all Verilated C files
 ///
-///	This file is included automatically by Verilator at the top of
-///	all C++ files it generates.  It is used when strings or other
-///	heavyweight types are required; these contents are not part of
-///	verilated.h to save compile time when such types aren't used.
+///     This file is included automatically by Verilator at the top of
+///     all C++ files it generates.  It is used when strings or other
+///     heavyweight types are required; these contents are not part of
+///     verilated.h to save compile time when such types aren't used.
 ///
 /// Code available from: http://www.veripool.org/verilator
 ///
@@ -36,33 +36,49 @@
 //======================================================================
 // Conversion functions

-extern string VL_CVT_PACK_STR_NW(int lwords, WDataInP lwp);
-inline string VL_CVT_PACK_STR_NQ(QData lhs) {
-    IData lw[2];  VL_SET_WQ(lw, lhs);
+extern std::string VL_CVT_PACK_STR_NW(int lwords, WDataInP lwp) VL_MT_SAFE;
+inline std::string VL_CVT_PACK_STR_NQ(QData lhs) VL_PURE {
+    WData lw[2];  VL_SET_WQ(lw, lhs);
    return VL_CVT_PACK_STR_NW(2, lw);
 }
-inline string VL_CVT_PACK_STR_NN(const string& lhs) {
+inline std::string VL_CVT_PACK_STR_NN(const std::string& lhs) VL_PURE {
    return lhs;
 }
-inline string VL_CVT_PACK_STR_NI(IData lhs) {
-    IData lw[1];  lw[0] = lhs;
+inline std::string VL_CVT_PACK_STR_NI(IData lhs) VL_PURE {
+    WData lw[1];  lw[0] = lhs;
    return VL_CVT_PACK_STR_NW(1, lw);
 }
-inline string VL_CONCATN_NNN(const string& lhs, const string& rhs) {
+inline std::string VL_CONCATN_NNN(const std::string& lhs, const std::string& rhs) VL_PURE {
    return lhs+rhs;
 }
-inline string VL_REPLICATEN_NNQ(int,int,int, const string& lhs, IData rep) {
-    string out; out.reserve(lhs.length() * rep);
-    for (unsigned times=0; times<rep; times++) out += lhs;
+inline std::string VL_REPLICATEN_NNQ(int,int,int, 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;
 }
-inline string VL_REPLICATEN_NNI(int obits,int lbits,int rbits, const string& lhs, IData rep) {
+inline std::string VL_REPLICATEN_NNI(int obits,int lbits,int rbits, const std::string& lhs, IData rep) VL_PURE {
    return VL_REPLICATEN_NNQ(obits,lbits,rbits,lhs,rep);
 }

-extern IData VL_FOPEN_NI(const string& filename, IData mode);
-extern IData VL_SSCANF_INX(int lbits, const string& ld, const char* formatp, ...);
-extern void VL_SFORMAT_X(int obits_ignored, string &output, const char* formatp, ...);
-extern string VL_SFORMATF_NX(const char* formatp, ...);
+extern IData VL_FOPEN_NI(const std::string& filename, IData mode) VL_MT_SAFE;
+extern void VL_READMEM_N(bool hex, int width, int depth, int array_lsb, int fnwords,
+                         const std::string& ofilename, void* memp, IData start, IData end) VL_MT_SAFE;
+extern IData VL_SSCANF_INX(int lbits, const std::string& ld, const char* formatp, ...) VL_MT_SAFE;
+extern void VL_SFORMAT_X(int obits_ignored, std::string &output, const char* formatp, ...) VL_MT_SAFE;
+extern std::string VL_SFORMATF_NX(const char* formatp, ...) VL_MT_SAFE;
+extern IData VL_VALUEPLUSARGS_INW(int rbits, const std::string& ld, WDataOutP rdp) VL_MT_SAFE;
+inline IData VL_VALUEPLUSARGS_INI(int rbits, const std::string& ld, IData& rdr) VL_MT_SAFE {
+    WData rwp[2];  // WData must always be at least 2
+    IData got = VL_VALUEPLUSARGS_INW(rbits,ld,rwp);
+    if (got) rdr = rwp[0];
+    return got;
+}
+inline IData VL_VALUEPLUSARGS_INQ(int rbits, const std::string& ld, QData& rdr) VL_MT_SAFE {
+    WData rwp[2];
+    IData got = VL_VALUEPLUSARGS_INW(rbits,ld,rwp);
+    if (got) rdr = VL_SET_QW(rwp);
+    return got;
+}
+extern IData VL_VALUEPLUSARGS_INN(int, const std::string& ld, std::string& rdr) VL_MT_SAFE;

 #endif // Guard
@@ -1,7 +1,7 @@
 // -*- mode: C++; c-file-style: "cc-mode" -*-
 //*************************************************************************
 //
-// Copyright 2009-2015 by Wilson Snyder. This program is free software; you can
+// Copyright 2009-2017 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.
@@ -34,104 +34,254 @@
 #include "verilated_syms.h"

 #include <map>
+#include <set>
 #include <vector>
 #include <deque>
 #include <string>
+#ifdef VL_THREADED
+# include <functional>
+# include <queue>
+#endif

 class VerilatedScope;

 //======================================================================
-// Types
+// Threaded message passing
+
+#ifdef VL_THREADED
+/// Message, enqueued on a train, and consumed on the main eval thread
+class VerilatedMsg {
+public:
+    // TYPES
+    struct Cmp {
+	bool operator() (const VerilatedMsg& a, const VerilatedMsg& b) {
+	    return a.trainId() < b.trainId(); }
+    };
+private:
+    // MEMBERS
+    vluint32_t 		m_trainId;  	///< Train that did enqueue
+    std::function<void()> m_cb; 	///< Lambda to execute when message received
+public:
+    // CONSTRUCTORS
+    VerilatedMsg(const std::function<void()>& cb)
+	: m_trainId(Verilated::trainId()), m_cb(cb) {}
+    ~VerilatedMsg() {}
+    // METHODS
+    vluint32_t trainId() const { return m_trainId; }
+    /// Execute the lambda function
+    void run() const { m_cb(); }
+};
+
+/// Each thread has a queue it pushes to
+/// This assumes no thread starts pushing the next tick until the previous has drained.
+/// If more aggressiveness is needed, a double-buffered scheme might work well.
+class VerilatedEvalMsgQueue  {
+    typedef std::multiset<VerilatedMsg, VerilatedMsg::Cmp> VerilatedThreadQueue;
+
+    std::atomic<vluint64_t> m_depth;  ///< Current depth of queue (see comments below)
+
+    VerilatedMutex m_mutex;  ///< Mutex protecting queue
+    VerilatedThreadQueue m_queue VL_GUARDED_BY(m_mutex);  ///< Message queue
+public:
+    // CONSTRUCTORS
+    VerilatedEvalMsgQueue() : m_depth(0) { }
+    ~VerilatedEvalMsgQueue() { }
+private:
+    VL_UNCOPYABLE(VerilatedEvalMsgQueue);
+public:
+    // METHODS
+    //// Add message to queue (called by producer)
+    void post(const VerilatedMsg& msg) VL_EXCLUDES(m_mutex) {
+	Verilated::endOfEvalReqdInc(); // No mutex, threadsafe
+	VerilatedLockGuard guard(m_mutex);
+	m_queue.insert(msg);  // Pass by value to copy the message into queue
+	++m_depth;
+    }
+    /// Service queue until completion (called by consumer)
+    void process() VL_EXCLUDES(m_mutex) {
+	// Tracking m_depth is redundant to e.g. getting the mutex and looking at queue size,
+	// but on the reader side it's 4x faster to test an atomic then getting a mutex
+	while (m_depth) {
+	    // Wait for a message to be added to the queue
+	    // We don't use unique_lock as want to unlock with the message copy still in scope
+	    m_mutex.lock();
+	    assert(!m_queue.empty()); // Otherwise m_depth is wrong
+	    // Unfortunately to release the lock we need to copy the message
+	    // (Or have the message be a pointer, but then new/delete cost on each message)
+	    // We assume messages are small, so copy
+	    auto it = m_queue.begin();
+	    const VerilatedMsg msg = *(it);
+	    m_queue.erase(it);
+	    m_mutex.unlock();
+	    m_depth--;  // Ok if outside critical section as only this code checks the value
+	    Verilated::endOfEvalReqdDec(); // No mutex, threadsafe
+	    {
+		VL_DEBUG_IF(VL_DBG_MSGF("Executing callback from trainId=%d\n", msg.trainId()););
+		msg.run();
+	    }
+	}
+    }
+};
+
+/// Each thread has a local queue to build up messages until the end of the eval() call
+class VerilatedThreadMsgQueue  {
+    std::queue<VerilatedMsg> m_queue;
+public:
+    // CONSTRUCTORS
+    VerilatedThreadMsgQueue() { }
+    ~VerilatedThreadMsgQueue() {
+	// The only call of this with a non-empty queue is a fatal error.
+	// So this does not flush the queue, as the destination queue is not known to this class.
+    }
+private:
+    VL_UNCOPYABLE(VerilatedThreadMsgQueue);
+    // METHODS
+    static VerilatedThreadMsgQueue& threadton() {
+	static VL_THREAD_LOCAL VerilatedThreadMsgQueue t_s;
+	return t_s;
+    }
+public:
+    /// Add message to queue, called by producer
+    static void post(const VerilatedMsg& msg) VL_MT_SAFE {
+	Verilated::endOfEvalReqdInc();
+	threadton().m_queue.push(msg);  // Pass by value to copy the message into queue
+    }
+    /// Push all messages to the eval's queue
+    static void flush(VerilatedEvalMsgQueue* evalMsgQp) VL_MT_SAFE {
+	while (!threadton().m_queue.empty()) {
+	    evalMsgQp->post(threadton().m_queue.front());
+	    threadton().m_queue.pop();
+	    Verilated::endOfEvalReqdDec();
+	}
+    }
+};
+#endif // VL_THREADED
+
+//======================================================================
+// VerilatedImp

 class VerilatedImp {
    // Whole class is internal use only - Global information shared between verilated*.cpp files.

    // TYPES
-    typedef vector<string> ArgVec;
-    typedef map<pair<const void*,void*>,void*> UserMap;
-    typedef map<const char*, int, VerilatedCStrCmp>  ExportNameMap;
+    typedef std::vector<std::string> ArgVec;
+    typedef std::map<std::pair<const void*,void*>,void*> UserMap;
+    typedef std::map<const char*, int, VerilatedCStrCmp>  ExportNameMap;

    // MEMBERS
    static VerilatedImp	s_s;		///< Static Singleton; One and only static this

    // Nothing here is save-restored; users expected to re-register appropriately

-    ArgVec		m_argVec;	///< Argument list (NOT save-restored, may want different results)
-    bool		m_argVecLoaded;	///< Ever loaded argument list
-    UserMap	 	m_userMap;	///< Map of <(scope,userkey), userData>
-    VerilatedScopeNameMap	m_nameMap;	///< Map of <scope_name, scope pointer>
+    VerilatedMutex      m_argMutex;  ///< Protect m_argVec, m_argVecLoaded
+    ArgVec              m_argVec VL_GUARDED_BY(m_argMutex);  ///< Argument list (NOT save-restored, may want different results)
+    bool                m_argVecLoaded VL_GUARDED_BY(m_argMutex);  ///< Ever loaded argument list
+
+    VerilatedMutex      m_userMapMutex;  ///< Protect m_userMap
+    UserMap             m_userMap VL_GUARDED_BY(m_userMapMutex);  ///< Map of <(scope,userkey), userData>
+
+    VerilatedMutex      m_nameMutex;  ///< Protect m_nameMap
+    VerilatedScopeNameMap m_nameMap VL_GUARDED_BY(m_nameMutex);  ///< Map of <scope_name, scope pointer>
    // Slow - somewhat static:
-    ExportNameMap	m_exportMap;	///< Map of <export_func_proto, func number>
-    int			m_exportNext;	///< Next export funcnum
+    VerilatedMutex      m_exportMutex;  ///< Protect m_nameMap
+    ExportNameMap       m_exportMap VL_GUARDED_BY(m_exportMutex);  ///< Map of <export_func_proto, func number>
+    int                 m_exportNext VL_GUARDED_BY(m_exportMutex);  ///< Next export funcnum

    // File I/O
-    vector<FILE*>	m_fdps;		///< File descriptors
-    deque<IData>	m_fdFree;	///< List of free descriptors (SLOW - FOPEN/CLOSE only)
+    VerilatedMutex      m_fdMutex;  ///< Protect m_fdps, m_fdFree
+    std::vector<FILE*>  m_fdps VL_GUARDED_BY(m_fdMutex);  ///< File descriptors
+    std::deque<IData>   m_fdFree VL_GUARDED_BY(m_fdMutex);  ///< List of free descriptors (SLOW - FOPEN/CLOSE only)
+
+    // Threads
+    VerilatedMutex      m_threadMutex;  ///< Protect m_numThreads, etc
+    bool                m_spawned VL_GUARDED_BY(m_threadMutex);  ///< Already called spawnThreads()
+    unsigned            m_numThreads VL_GUARDED_BY(m_threadMutex);  ///< Number of threads user requested, 0x0=all cpus

 public: // But only for verilated*.cpp
    // CONSTRUCTORS
-    VerilatedImp() : m_argVecLoaded(false), m_exportNext(0) {
+    VerilatedImp()
+	: m_argVecLoaded(false), m_exportNext(0), m_spawned(false), m_numThreads(0) {
 	m_fdps.resize(3);
 	m_fdps[0] = stdin;
 	m_fdps[1] = stdout;
 	m_fdps[2] = stderr;
    }
    ~VerilatedImp() {}
-    static void internalsDump() {
-	VL_PRINTF("internalsDump:\n");
-	VL_PRINTF("  Argv:");
-	for (ArgVec::iterator it=s_s.m_argVec.begin(); it!=s_s.m_argVec.end(); ++it) {
-	    VL_PRINTF(" %s",it->c_str());
+private:
+    VL_UNCOPYABLE(VerilatedImp);
+public:
+    static void internalsDump() VL_MT_SAFE {
+	VerilatedLockGuard guard(s_s.m_argMutex);
+	VL_PRINTF_MT("internalsDump:\n");
+	VL_PRINTF_MT("  Argv:");
+	for (ArgVec::const_iterator it=s_s.m_argVec.begin(); it!=s_s.m_argVec.end(); ++it) {
+	    VL_PRINTF_MT(" %s",it->c_str());
 	}
-	VL_PRINTF("\n");
-	VL_PRINTF("  Version: %s %s\n", Verilated::productName(), Verilated::productVersion());
+	VL_PRINTF_MT("\n");
+	VL_PRINTF_MT("  Version: %s %s\n", Verilated::productName(), Verilated::productVersion());
 	scopesDump();
 	exportsDump();
 	userDump();
    }

    // METHODS - arguments
-    static void commandArgs(int argc, const char** argv) {
-	s_s.m_argVec.clear();
-	for (int i=0; i<argc; i++) s_s.m_argVec.push_back(argv[i]);
-	s_s.m_argVecLoaded = true; // Can't just test later for empty vector, no arguments is ok
+public:
+    static void commandArgs(int argc, const char** argv) VL_EXCLUDES(s_s.m_argMutex) {
+	VerilatedLockGuard guard(s_s.m_argMutex);
+	s_s.m_argVec.clear();  // Always clear
+	commandArgsAddGuts(argc, argv);
    }
-    static string argPlusMatch(const char* prefixp) {
+    static void commandArgsAdd(int argc, const char** argv) VL_EXCLUDES(s_s.m_argMutex) {
+	VerilatedLockGuard guard(s_s.m_argMutex);
+	commandArgsAddGuts(argc, argv);
+    }
+    static std::string argPlusMatch(const char* prefixp) VL_EXCLUDES(s_s.m_argMutex) {
+	VerilatedLockGuard guard(s_s.m_argMutex);
 	// Note prefixp does not include the leading "+"
 	size_t len = strlen(prefixp);
 	if (VL_UNLIKELY(!s_s.m_argVecLoaded)) {
 	    s_s.m_argVecLoaded = true;  // Complain only once
-	    vl_fatal("unknown",0,"",
-		     "%Error: Verilog called $test$plusargs or $value$plusargs without"
-		     " testbench C first calling Verilated::commandArgs(argc,argv).");
+	    VL_FATAL_MT("unknown",0,"",
+			"%Error: Verilog called $test$plusargs or $value$plusargs without"
+			" testbench C first calling Verilated::commandArgs(argc,argv).");
 	}
-	for (ArgVec::iterator it=s_s.m_argVec.begin(); it!=s_s.m_argVec.end(); ++it) {
+	for (ArgVec::const_iterator it=s_s.m_argVec.begin(); it!=s_s.m_argVec.end(); ++it) {
 	    if ((*it)[0]=='+') {
 		if (0==strncmp(prefixp, it->c_str()+1, len)) return *it;
 	    }
 	}
 	return "";
    }
+private:
+    static void commandArgsAddGuts(int argc, const char** argv) VL_REQUIRES(s_s.m_argMutex) {
+	if (!s_s.m_argVecLoaded) s_s.m_argVec.clear();
+	for (int i=0; i<argc; ++i) s_s.m_argVec.push_back(argv[i]);
+	s_s.m_argVecLoaded = true; // Can't just test later for empty vector, no arguments is ok
+    }

+public:
    // METHODS - user scope tracking
    // We implement this as a single large map instead of one map per scope
    // There's often many more scopes than userdata's and thus having a ~48byte
    // per map overhead * N scopes would take much more space and cache thrashing.
-    static inline void userInsert(const void* scopep, void* userKey, void* userData) {
-	UserMap::iterator it=s_s.m_userMap.find(make_pair(scopep,userKey));
+    static inline void userInsert(const void* scopep, void* userKey, void* userData) VL_MT_SAFE {
+	VerilatedLockGuard guard(s_s.m_userMapMutex);
+	UserMap::iterator it=s_s.m_userMap.find(std::make_pair(scopep,userKey));
 	if (it != s_s.m_userMap.end()) it->second = userData;
 	// When we support VL_THREADs, we need a lock around this insert, as it's runtime
-	else s_s.m_userMap.insert(it, make_pair(make_pair(scopep,userKey),userData));
+	else s_s.m_userMap.insert(it, std::make_pair(std::make_pair(scopep,userKey),userData));
    }
-    static inline void* userFind(const void* scopep, void* userKey) {
-	UserMap::iterator it=s_s.m_userMap.find(make_pair(scopep,userKey));
+    static inline void* userFind(const void* scopep, void* userKey) VL_MT_SAFE {
+	VerilatedLockGuard guard(s_s.m_userMapMutex);
+	UserMap::const_iterator it=s_s.m_userMap.find(std::make_pair(scopep,userKey));
 	if (VL_LIKELY(it != s_s.m_userMap.end())) return it->second;
 	else return NULL;
    }
 private:
    /// Symbol table destruction cleans up the entries for each scope.
-    static void userEraseScope(const VerilatedScope* scopep) {
+    static void userEraseScope(const VerilatedScope* scopep) VL_MT_SAFE {
 	// Slow ok - called once/scope on destruction, so we simply iterate.
+	VerilatedLockGuard guard(s_s.m_userMapMutex);
 	for (UserMap::iterator it=s_s.m_userMap.begin(); it!=s_s.m_userMap.end(); ) {
 	    if (it->first.first == scopep) {
 		s_s.m_userMap.erase(it++);
@@ -140,44 +290,50 @@ private:
 	    }
 	}
    }
-    static void userDump() {
+    static void userDump() VL_MT_SAFE {
+	VerilatedLockGuard guard(s_s.m_userMapMutex);  // Avoid it changing in middle of dump
 	bool first = true;
-	for (UserMap::iterator it=s_s.m_userMap.begin(); it!=s_s.m_userMap.end(); ++it) {
-	    if (first) { VL_PRINTF("  userDump:\n"); first=false; }
-	    VL_PRINTF("    DPI_USER_DATA scope %p key %p: %p\n",
+	for (UserMap::const_iterator it=s_s.m_userMap.begin(); it!=s_s.m_userMap.end(); ++it) {
+	    if (first) { VL_PRINTF_MT("  userDump:\n"); first=false; }
+	    VL_PRINTF_MT("    DPI_USER_DATA scope %p key %p: %p\n",
 		      it->first.first, it->first.second, it->second);
 	}
    }

 public: // But only for verilated*.cpp
    // METHODS - scope name
-    static void scopeInsert(const VerilatedScope* scopep) {
+    static void scopeInsert(const VerilatedScope* scopep) VL_MT_SAFE {
 	// Slow ok - called once/scope at construction
+	VerilatedLockGuard guard(s_s.m_nameMutex);
 	VerilatedScopeNameMap::iterator it=s_s.m_nameMap.find(scopep->name());
 	if (it == s_s.m_nameMap.end()) {
-	    s_s.m_nameMap.insert(it, make_pair(scopep->name(),scopep));
+	    s_s.m_nameMap.insert(it, std::make_pair(scopep->name(),scopep));
 	}
    }
-    static inline const VerilatedScope* scopeFind(const char* namep) {
-	VerilatedScopeNameMap::iterator it=s_s.m_nameMap.find(namep);
+    static inline const VerilatedScope* scopeFind(const char* namep) VL_MT_SAFE {
+	VerilatedLockGuard guard(s_s.m_nameMutex);  // If too slow, can assume this is only VL_MT_SAFE_POSINIT
+	VerilatedScopeNameMap::const_iterator it=s_s.m_nameMap.find(namep);
 	if (VL_LIKELY(it != s_s.m_nameMap.end())) return it->second;
 	else return NULL;
    }
-    static void scopeErase(const VerilatedScope* scopep) {
+    static void scopeErase(const VerilatedScope* scopep) VL_MT_SAFE {
 	// Slow ok - called once/scope at destruction
+	VerilatedLockGuard guard(s_s.m_nameMutex);
 	userEraseScope(scopep);
 	VerilatedScopeNameMap::iterator it=s_s.m_nameMap.find(scopep->name());
 	if (it != s_s.m_nameMap.end()) s_s.m_nameMap.erase(it);
    }
-    static void scopesDump() {
-	VL_PRINTF("  scopesDump:\n");
-	for (VerilatedScopeNameMap::iterator it=s_s.m_nameMap.begin(); it!=s_s.m_nameMap.end(); ++it) {
+    static void scopesDump() VL_MT_SAFE {
+	VerilatedLockGuard guard(s_s.m_nameMutex);
+	VL_PRINTF_MT("  scopesDump:\n");
+	for (VerilatedScopeNameMap::const_iterator it=s_s.m_nameMap.begin(); it!=s_s.m_nameMap.end(); ++it) {
 	    const VerilatedScope* scopep = it->second;
 	    scopep->scopeDump();
 	}
-	VL_PRINTF("\n");
+	VL_PRINTF_MT("\n");
    }
-    static const VerilatedScopeNameMap* scopeNameMap() {
+    static const VerilatedScopeNameMap* scopeNameMap() VL_MT_SAFE_POSTINIT {
+	// Thread save only assuming this is called only after model construction completed
        return &s_s.m_nameMap;
    }

@@ -190,36 +346,40 @@ public: // But only for verilated*.cpp
    // in the design that also happen to have our same callback function.
    // Rather than a 2D map, the integer scheme saves 500ish ns on a likely
    // miss at the cost of a multiply, and all lookups move to slowpath.
-    static int exportInsert(const char* namep) {
+    static int exportInsert(const char* namep) VL_MT_SAFE {
 	// Slow ok - called once/function at creation
+	VerilatedLockGuard guard(s_s.m_exportMutex);
 	ExportNameMap::iterator it=s_s.m_exportMap.find(namep);
 	if (it == s_s.m_exportMap.end()) {
-	    s_s.m_exportMap.insert(it, make_pair(namep, s_s.m_exportNext++));
+	    s_s.m_exportMap.insert(it, std::make_pair(namep, s_s.m_exportNext++));
 	    return s_s.m_exportNext++;
 	} else {
 	    return it->second;
 	}
    }
-    static int exportFind(const char* namep) {
-	ExportNameMap::iterator it=s_s.m_exportMap.find(namep);
+    static int exportFind(const char* namep) VL_MT_SAFE {
+	VerilatedLockGuard guard(s_s.m_exportMutex);
+	ExportNameMap::const_iterator it=s_s.m_exportMap.find(namep);
 	if (VL_LIKELY(it != s_s.m_exportMap.end())) return it->second;
-	string msg = (string("%Error: Testbench C called ")+namep
-		      +" but no such DPI export function name exists in ANY model");
-	vl_fatal("unknown",0,"", msg.c_str());
+	std::string msg = (std::string("%Error: Testbench C called ")+namep
+			   +" but no such DPI export function name exists in ANY model");
+	VL_FATAL_MT("unknown",0,"", msg.c_str());
 	return -1;
    }
-    static const char* exportName(int funcnum) {
+    static const char* exportName(int funcnum) VL_MT_SAFE {
 	// Slowpath; find name for given export; errors only so no map to reverse-map it
-	for (ExportNameMap::iterator it=s_s.m_exportMap.begin(); it!=s_s.m_exportMap.end(); ++it) {
+	VerilatedLockGuard guard(s_s.m_exportMutex);
+	for (ExportNameMap::const_iterator it=s_s.m_exportMap.begin(); it!=s_s.m_exportMap.end(); ++it) {
 	    if (it->second == funcnum) return it->first;
 	}
 	return "*UNKNOWN*";
    }
-    static void exportsDump() {
+    static void exportsDump() VL_MT_SAFE {
+	VerilatedLockGuard guard(s_s.m_exportMutex);
 	bool first = true;
-	for (ExportNameMap::iterator it=s_s.m_exportMap.begin(); it!=s_s.m_exportMap.end(); ++it) {
-	    if (first) { VL_PRINTF("  exportDump:\n"); first=false; }
-	    VL_PRINTF("    DPI_EXPORT_NAME %05d: %s\n", it->second, it->first);
+	for (ExportNameMap::const_iterator it=s_s.m_exportMap.begin(); it!=s_s.m_exportMap.end(); ++it) {
+	    if (first) { VL_PRINTF_MT("  exportDump:\n"); first=false; }
+	    VL_PRINTF_MT("    DPI_EXPORT_NAME %05d: %s\n", it->second, it->first);
 	}
    }
    // We don't free up m_exportMap until the end, because we can't be sure
@@ -227,31 +387,67 @@ public: // But only for verilated*.cpp

 public: // But only for verilated*.cpp
    // METHODS - file IO
-    static IData fdNew(FILE* fp) {
+    static IData fdNew(FILE* fp) VL_MT_SAFE {
 	if (VL_UNLIKELY(!fp)) return 0;
 	// Bit 31 indicates it's a descriptor not a MCD
+	VerilatedLockGuard guard(s_s.m_fdMutex);
 	if (s_s.m_fdFree.empty()) {
 	    // Need to create more space in m_fdps and m_fdFree
 	    size_t start = s_s.m_fdps.size();
 	    s_s.m_fdps.resize(start*2);
-	    for (size_t i=start; i<start*2; i++) s_s.m_fdFree.push_back((IData)i);
+	    for (size_t i=start; i<start*2; ++i) s_s.m_fdFree.push_back(static_cast<IData>(i));
 	}
 	IData idx = s_s.m_fdFree.back(); s_s.m_fdFree.pop_back();
 	s_s.m_fdps[idx] = fp;
 	return (idx | (1UL<<31));  // bit 31 indicates not MCD
    }
-    static void fdDelete(IData fdi) {
+    static void fdDelete(IData fdi) VL_MT_SAFE {
 	IData idx = VL_MASK_I(31) & fdi;
+	VerilatedLockGuard guard(s_s.m_fdMutex);
 	if (VL_UNLIKELY(!(fdi & (1ULL<<31)) || idx >= s_s.m_fdps.size())) return;
 	if (VL_UNLIKELY(!s_s.m_fdps[idx])) return;  // Already free
 	s_s.m_fdps[idx] = NULL;
 	s_s.m_fdFree.push_back(idx);
    }
-    static inline FILE* fdToFp(IData fdi) {
+    static inline FILE* fdToFp(IData fdi) VL_MT_SAFE {
 	IData idx = VL_MASK_I(31) & fdi;
+	VerilatedLockGuard guard(s_s.m_fdMutex);  // This might get slow, if it does we can cache it
 	if (VL_UNLIKELY(!(fdi & (1ULL<<31)) || idx >= s_s.m_fdps.size())) return NULL;
 	return s_s.m_fdps[idx];
    }
+
+public: // But only for verilated*.cpp
+    // METHODS - Threading
+    static void numThreads(unsigned threads) VL_MT_SAFE {
+	VerilatedLockGuard guard(s_s.m_threadMutex);
+	if (!s_s.m_spawned) s_s.m_numThreads = threads;
+    }
+    static unsigned numThreads() VL_MT_SAFE {
+	VerilatedLockGuard guard(s_s.m_threadMutex);
+#ifdef VL_THREADED
+	unsigned threads = s_s.m_numThreads;
+	if (threads == 0x0) {
+	    threads = std::thread::hardware_concurrency(); // Or 0=unknown, C++11
+	}
+	if (threads<1) threads = 1;
+	return threads;
+#else
+	return 0;
+#endif
+    }
+    static void spawnThreads() VL_MT_SAFE {
+	VerilatedLockGuard guard(s_s.m_threadMutex);
+	if (!s_s.m_spawned) {
+	    // Convert numThreads from 0 to the spawned number
+	    numThreads(numThreads());
+	    s_s.m_spawned = true;
+#ifdef VL_THREADED
+	    // THREADED-TODO startup threads
+#endif
+	}
+    }
 };

+//======================================================================
+
 #endif  // Guard
@@ -3,7 +3,7 @@
 //
 // THIS MODULE IS PUBLICLY LICENSED
 //
-// Copyright 2001-2015 by Wilson Snyder.  This program is free software;
+// Copyright 2001-2017 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.
 //
@@ -40,15 +40,15 @@
 #endif

 // CONSTANTS
-static const char* VLTSAVE_HEADER_STR = "verilatorsave01\n";	///< Value of first bytes of each file
-static const char* VLTSAVE_TRAILER_STR = "vltsaved";	///< Value of last bytes of each file
+static const char* const VLTSAVE_HEADER_STR = "verilatorsave01\n";	///< Value of first bytes of each file
+static const char* const VLTSAVE_TRAILER_STR = "vltsaved";	///< Value of last bytes of each file

 //=============================================================================
 //=============================================================================
 //=============================================================================
 // Searalization

-bool VerilatedDeserialize::readDiffers (const void* __restrict datap, size_t size) {
+bool VerilatedDeserialize::readDiffers (const void* __restrict datap, size_t size) VL_MT_UNSAFE_ONE {
    bufferCheck();
    const vluint8_t* __restrict dp = (const vluint8_t* __restrict)datap;
    vluint8_t miss = 0;
@@ -58,17 +58,17 @@ bool VerilatedDeserialize::readDiffers (const void* __restrict datap, size_t siz
    return (miss!=0);
 }

-VerilatedDeserialize& VerilatedDeserialize::readAssert (const void* __restrict datap, size_t size) {
+VerilatedDeserialize& VerilatedDeserialize::readAssert (const void* __restrict datap, size_t size) VL_MT_UNSAFE_ONE {
    if (VL_UNLIKELY(readDiffers(datap,size))) {
-	string fn = filename();
-	string msg = (string)"Can't deserialize save-restore file as was made from different model";
-	vl_fatal(fn.c_str(), 0, "", msg.c_str());
+	std::string fn = filename();
+	std::string msg = std::string("Can't deserialize save-restore file as was made from different model");
+	VL_FATAL_MT(fn.c_str(), 0, "", msg.c_str());
 	close();
    }
    return *this;  // For function chaining
 }

-void VerilatedSerialize::header() {
+void VerilatedSerialize::header() VL_MT_UNSAFE_ONE {
    VerilatedSerialize& os = *this;  // So can cut and paste standard << code below
    assert((strlen(VLTSAVE_HEADER_STR) & 7) == 0);  // Keep aligned
    os.write(VLTSAVE_HEADER_STR, strlen(VLTSAVE_HEADER_STR));
@@ -78,29 +78,29 @@ void VerilatedSerialize::header() {
    os.write(Verilated::serializedPtr(), Verilated::serializedSize());
 }

-void VerilatedDeserialize::header() {
+void VerilatedDeserialize::header() VL_MT_UNSAFE_ONE {
    VerilatedDeserialize& os = *this;  // So can cut and paste standard >> code below
    if (VL_UNLIKELY(os.readDiffers(VLTSAVE_HEADER_STR, strlen(VLTSAVE_HEADER_STR)))) {
-	string fn = filename();
-	string msg = (string)"Can't deserialize; file has wrong header signature";
-	vl_fatal(fn.c_str(), 0, "", msg.c_str());
+	std::string fn = filename();
+	std::string msg = std::string("Can't deserialize; file has wrong header signature");
+	VL_FATAL_MT(fn.c_str(), 0, "", msg.c_str());
 	close();
    }
    os.read(Verilated::serializedPtr(), Verilated::serializedSize());
 }

-void VerilatedSerialize::trailer() {
+void VerilatedSerialize::trailer() VL_MT_UNSAFE_ONE {
    VerilatedSerialize& os = *this;  // So can cut and paste standard << code below
    assert((strlen(VLTSAVE_TRAILER_STR) & 7) == 0);  // Keep aligned
    os.write(VLTSAVE_TRAILER_STR, strlen(VLTSAVE_TRAILER_STR));
 }

-void VerilatedDeserialize::trailer() {
+void VerilatedDeserialize::trailer() VL_MT_UNSAFE_ONE {
    VerilatedDeserialize& os = *this;  // So can cut and paste standard >> code below
    if (VL_UNLIKELY(os.readDiffers(VLTSAVE_TRAILER_STR, strlen(VLTSAVE_TRAILER_STR)))) {
-	string fn = filename();
-	string msg = (string)"Can't deserialize; file has wrong end-of-file signature";
-	vl_fatal(fn.c_str(), 0, "", msg.c_str());
+	std::string fn = filename();
+	std::string msg = std::string("Can't deserialize; file has wrong end-of-file signature");
+	VL_FATAL_MT(fn.c_str(), 0, "", msg.c_str());
 	close();
    }
 }
@@ -110,9 +110,10 @@ void VerilatedDeserialize::trailer() {
 //=============================================================================
 // Opening/Closing

-void VerilatedSave::open (const char* filenamep) {
+void VerilatedSave::open(const char* filenamep) VL_MT_UNSAFE_ONE {
+    m_assertOne.check();
    if (isOpen()) return;
-    VL_DEBUG_IF(VL_PRINTF("-vltSave: opening save file %s\n",filenamep););
+    VL_DEBUG_IF(VL_DBG_MSGF("- save: opening save file %s\n",filenamep););

    if (filenamep[0]=='|') {
 	assert(0);	// Not supported yet.
@@ -132,9 +133,10 @@ void VerilatedSave::open (const char* filenamep) {
    header();
 }

-void VerilatedRestore::open (const char* filenamep) {
+void VerilatedRestore::open(const char* filenamep) VL_MT_UNSAFE_ONE {
+    m_assertOne.check();
    if (isOpen()) return;
-    VL_DEBUG_IF(VL_PRINTF("-vltRestore: opening restore file %s\n",filenamep););
+    VL_DEBUG_IF(VL_DBG_MSGF("- restore: opening restore file %s\n",filenamep););

    if (filenamep[0]=='|') {
 	assert(0);	// Not supported yet.
@@ -155,7 +157,7 @@ void VerilatedRestore::open (const char* filenamep) {
    header();
 }

-void VerilatedSave::close () {
+void VerilatedSave::close() VL_MT_UNSAFE_ONE {
    if (!isOpen()) return;
    trailer();
    flush();
@@ -163,7 +165,7 @@ void VerilatedSave::close () {
    ::close(m_fd);  // May get error, just ignore it
 }

-void VerilatedRestore::close () {
+void VerilatedRestore::close() VL_MT_UNSAFE_ONE {
    if (!isOpen()) return;
    trailer();
    flush();
@@ -174,7 +176,8 @@ void VerilatedRestore::close () {
 //=============================================================================
 // Buffer management

-void VerilatedSave::flush() {
+void VerilatedSave::flush() VL_MT_UNSAFE_ONE {
+    m_assertOne.check();
    if (VL_UNLIKELY(!isOpen())) return;
    vluint8_t* wp = m_bufp;
    while (1) {
@@ -187,8 +190,8 @@ void VerilatedSave::flush() {
 	} else if (got < 0) {
 	    if (errno != EAGAIN && errno != EINTR) {
 		// write failed, presume error (perhaps out of disk space)
-		string msg = string(__FUNCTION__)+": "+strerror(errno);
-		vl_fatal("",0,"",msg.c_str());
+		std::string msg = std::string(__FUNCTION__)+": "+strerror(errno);
+		VL_FATAL_MT("",0,"",msg.c_str());
 		close();
 		break;
 	    }
@@ -197,14 +200,15 @@ void VerilatedSave::flush() {
    m_cp = m_bufp; // Reset buffer
 }

-void VerilatedRestore::fill() {
+void VerilatedRestore::fill() VL_MT_UNSAFE_ONE {
+    m_assertOne.check();
    if (VL_UNLIKELY(!isOpen())) return;
    // Move remaining characters down to start of buffer.  (No memcpy, overlaps allowed)
    vluint8_t* rp = m_bufp;
-    for (vluint8_t* sp=m_cp; rp < m_endp;) *rp++ = *sp++;  // Overlaps
+    for (vluint8_t* sp=m_cp; sp < m_endp;) *rp++ = *sp++;  // Overlaps
    m_endp = m_bufp + (m_endp - m_cp);
    m_cp = m_bufp; // Reset buffer
-    // Read into buffer starting at m_endp 
+    // Read into buffer starting at m_endp
    while (1) {
 	ssize_t remaining = (m_bufp+bufferSize() - m_endp);
 	if (remaining==0) break;
@@ -215,8 +219,8 @@ void VerilatedRestore::fill() {
 	} else if (got < 0) {
 	    if (errno != EAGAIN && errno != EINTR) {
 		// write failed, presume error (perhaps out of disk space)
-		string msg = string(__FUNCTION__)+": "+strerror(errno);
-		vl_fatal("",0,"",msg.c_str());
+		std::string msg = std::string(__FUNCTION__)+": "+strerror(errno);
+		VL_FATAL_MT("",0,"",msg.c_str());
 		close();
 		break;
 	    }
@@ -3,7 +3,7 @@
 //
 // THIS MODULE IS PUBLICLY LICENSED
 //
-// Copyright 2012-2015 by Wilson Snyder.  This program is free software;
+// Copyright 2012-2017 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.
 //
@@ -25,67 +25,45 @@
 #include "verilatedos.h"

 #include <string>
-using namespace std;

 //=============================================================================
-// VerilatedSerialBase - internal base class for common code between VerilatedSerialize and VerilatedDeserialize
+// VerilatedSerialize - convert structures to a stream representation
+// This class is not thread safe, it must be called by a single thread

-class VerilatedSerialBase {
+class VerilatedSerialize {
 protected:
    // MEMBERS
    // For speed, keep m_cp as the first member of this structure
    vluint8_t*		m_cp;		///< Current pointer into m_bufp buffer
    vluint8_t*		m_bufp;		///< Output buffer
    bool 		m_isOpen;	///< True indicates open file/stream
-    string		m_filename;
+    std::string		m_filename;	///< Filename, for error messages
+    VerilatedAssertOneThread m_assertOne;  ///< Assert only called from single thread

    inline static size_t bufferSize() { return 256*1024; }  // See below for slack calculation
    inline static size_t bufferInsertSize() { return 16*1024; }

-    // CREATORS
-    VerilatedSerialBase() {
+    void header() VL_MT_UNSAFE_ONE;
+    void trailer() VL_MT_UNSAFE_ONE;
+
+    // CONSTRUCTORS
+    VL_UNCOPYABLE(VerilatedSerialize);
+public:
+    VerilatedSerialize() {
 	m_isOpen = false;
 	m_bufp = new vluint8_t [bufferSize()];
 	m_cp = m_bufp;
    }
-private:
-    VerilatedSerialBase(const VerilatedSerialBase& );	///< N/A, no copy constructor
-public:
-    // CREATORS
-    virtual ~VerilatedSerialBase() {
+    virtual ~VerilatedSerialize() {
 	close();
 	if (m_bufp) { delete m_bufp; m_bufp=NULL; }
    }
    // METHODS
    bool isOpen() const { return m_isOpen; }
-    string filename() const { return m_filename; }
-    virtual void close() { flush(); }
-    virtual void flush() {}
-};
-
-//=============================================================================
-// VerilatedSerialize - convert structures to a stream representation
-
-class VerilatedSerialize : public VerilatedSerialBase {
-protected:
-    virtual void close() { flush(); }
-    virtual void flush() {}
-    void header();
-    void trailer();
-public:
-    // CREATORS
-    VerilatedSerialize() {}
-    virtual ~VerilatedSerialize() { close(); }
-    // METHODS
-    VerilatedSerialize& bufferCheck() {
-	// Flush the write buffer if there's not enough space left for new information
-	// We only call this once per vector, so we need enough slop for a very wide "b###" line
-	if (VL_UNLIKELY(m_cp > (m_bufp+(bufferSize()-bufferInsertSize())))) {
-	    flush();
-	}
-	return *this;  // For function chaining
-    }
-    inline VerilatedSerialize& write (const void* __restrict datap, size_t size) {
+    std::string filename() const { return m_filename; }
+    virtual void close() VL_MT_UNSAFE_ONE { flush(); }
+    virtual void flush() VL_MT_UNSAFE_ONE {}
+    inline VerilatedSerialize& write(const void* __restrict datap, size_t size) VL_MT_UNSAFE_ONE {
 	const vluint8_t* __restrict dp = (const vluint8_t* __restrict)datap;
 	while (size) {
 	    bufferCheck();
@@ -96,23 +74,58 @@ public:
 	}
 	return *this;  // For function chaining
    }
+private:
+    VerilatedSerialize& bufferCheck() VL_MT_UNSAFE_ONE {
+	// Flush the write buffer if there's not enough space left for new information
+	// We only call this once per vector, so we need enough slop for a very wide "b###" line
+	if (VL_UNLIKELY(m_cp > (m_bufp+(bufferSize()-bufferInsertSize())))) {
+	    flush();
+	}
+	return *this;  // For function chaining
+    }
 };

 //=============================================================================
 // VerilatedDeserial - load structures from a stream representation
+// This class is not thread safe, it must be called by a single thread

-class VerilatedDeserialize : public VerilatedSerialBase {
+class VerilatedDeserialize {
 protected:
+    // MEMBERS
+    // For speed, keep m_cp as the first member of this structure
+    vluint8_t*		m_cp;		///< Current pointer into m_bufp buffer
+    vluint8_t*		m_bufp;		///< Output buffer
    vluint8_t*		m_endp;		///< Last valid byte in m_bufp buffer
+    bool 		m_isOpen;	///< True indicates open file/stream
+    std::string		m_filename;	///< Filename, for error messages
+    VerilatedAssertOneThread m_assertOne;	///< Assert only called from single thread
+
+    inline static size_t bufferSize() { return 256*1024; }  // See below for slack calculation
+    inline static size_t bufferInsertSize() { return 16*1024; }
+
    virtual void fill() = 0;
-    void header();
-    void trailer();
+    void header() VL_MT_UNSAFE_ONE;
+    void trailer() VL_MT_UNSAFE_ONE;
+
+    // CONSTRUCTORS
+    VL_UNCOPYABLE(VerilatedDeserialize);
 public:
-    // CREATORS
-    VerilatedDeserialize() { m_endp = NULL; }
-    virtual ~VerilatedDeserialize() { close(); }
+    VerilatedDeserialize() {
+	m_isOpen = false;
+	m_bufp = new vluint8_t [bufferSize()];
+	m_cp = m_bufp;
+	m_endp = NULL;
+    }
+    virtual ~VerilatedDeserialize() {
+	close();
+	if (m_bufp) { delete m_bufp; m_bufp=NULL; }
+    }
    // METHODS
-    inline VerilatedDeserialize& read (void* __restrict datap, size_t size) {
+    bool isOpen() const { return m_isOpen; }
+    std::string filename() const { return m_filename; }
+    virtual void close() VL_MT_UNSAFE_ONE { flush(); }
+    virtual void flush() VL_MT_UNSAFE_ONE {}
+    inline VerilatedDeserialize& read(void* __restrict datap, size_t size) VL_MT_UNSAFE_ONE {
 	vluint8_t* __restrict dp = (vluint8_t* __restrict)datap;
 	while (size) {
 	    bufferCheck();
@@ -124,10 +137,11 @@ public:
 	return *this;  // For function chaining
    }
    // Read a datum and compare with expected value
-    bool readDiffers (const void* __restrict datap, size_t size);
-    VerilatedDeserialize& readAssert (const void* __restrict datap, size_t size);
-    VerilatedDeserialize& readAssert (vluint64_t data) { return readAssert(&data, sizeof(data)); }
-    VerilatedDeserialize& bufferCheck() {
+    VerilatedDeserialize& readAssert(const void* __restrict datap, size_t size) VL_MT_UNSAFE_ONE;
+    VerilatedDeserialize& readAssert(vluint64_t data) VL_MT_UNSAFE_ONE { return readAssert(&data, sizeof(data)); }
+private:
+    bool readDiffers(const void* __restrict datap, size_t size) VL_MT_UNSAFE_ONE;
+    VerilatedDeserialize& bufferCheck() VL_MT_UNSAFE_ONE {
 	// Flush the write buffer if there's not enough space left for new information
 	// We only call this once per vector, so we need enough slop for a very wide "b###" line
 	if (VL_UNLIKELY((m_cp+bufferInsertSize()) > m_endp)) {
@@ -139,40 +153,42 @@ public:

 //=============================================================================
 // VerilatedSave - serialize to a file
+// This class is not thread safe, it must be called by a single thread

 class VerilatedSave : public VerilatedSerialize {
 private:
    int			m_fd;		///< File descriptor we're writing to

 public:
-    // CREATORS
+    // CONSTRUCTORS
    VerilatedSave() { m_fd=-1; }
    virtual ~VerilatedSave() { close(); }
    // METHODS
-    void open(const char* filenamep);	///< Open the file; call isOpen() to see if errors
-    void open(const string& filename) { open(filename.c_str()); }
-    virtual void close();
-    virtual void flush();
+    void open(const char* filenamep) VL_MT_UNSAFE_ONE;  ///< Open the file; call isOpen() to see if errors
+    void open(const std::string& filename) VL_MT_UNSAFE_ONE { open(filename.c_str()); }
+    virtual void close() VL_MT_UNSAFE_ONE;
+    virtual void flush() VL_MT_UNSAFE_ONE;
 };

 //=============================================================================
 // VerilatedRestore - deserialize from a file
+// This class is not thread safe, it must be called by a single thread

 class VerilatedRestore : public VerilatedDeserialize {
 private:
    int			m_fd;		///< File descriptor we're writing to

 public:
-    // CREATORS
+    // CONSTRUCTORS
    VerilatedRestore() { m_fd=-1; }
    virtual ~VerilatedRestore() { close(); }

    // METHODS
-    void open(const char* filenamep);	///< Open the file; call isOpen() to see if errors
-    void open(const string& filename) { open(filename.c_str()); }
-    virtual void close();
-    virtual void flush() {}
-    virtual void fill();
+    void open(const char* filenamep) VL_MT_UNSAFE_ONE;  ///< Open the file; call isOpen() to see if errors
+    void open(const std::string& filename) VL_MT_UNSAFE_ONE { open(filename.c_str()); }
+    virtual void close() VL_MT_UNSAFE_ONE;
+    virtual void flush() VL_MT_UNSAFE_ONE {}
+    virtual void fill() VL_MT_UNSAFE_ONE;
 };

 //=============================================================================
@@ -219,12 +235,12 @@ inline VerilatedSerialize&   operator<<(VerilatedSerialize& os,   float& rhs) {
 inline VerilatedDeserialize& operator>>(VerilatedDeserialize& os, float& rhs) {
    return os.read(&rhs, sizeof(rhs));
 }
-inline VerilatedSerialize&   operator<<(VerilatedSerialize& os,   string& rhs) {
+inline VerilatedSerialize&   operator<<(VerilatedSerialize& os,   std::string& rhs) {
    vluint32_t len=rhs.length();
    os<<len;
    return os.write(rhs.data(), len);
 }
-inline VerilatedDeserialize& operator>>(VerilatedDeserialize& os, string& rhs) {
+inline VerilatedDeserialize& operator>>(VerilatedDeserialize& os, std::string& rhs) {
    vluint32_t len=0;
    os>>len;
    rhs.resize(len);
@@ -1,7 +1,7 @@
 // -*- mode: C++; c-file-style: "cc-mode" -*-
 //*************************************************************************
 //
-// Copyright 2009-2015 by Wilson Snyder. This program is free software; you can
+// Copyright 2009-2017 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.
@@ -16,8 +16,8 @@
 /// \file
 /// \brief Verilator: Common include for all Verilated SystemC files
 ///
-///	This file is included automatically by Verilator at the top of
-///	all SystemC files it generates.
+///     This file is included automatically by Verilator at the top of
+///     all SystemC files it generates.
 ///
 /// Code available from: http://www.veripool.org/verilator
 ///
@@ -35,13 +35,14 @@
 // We want to get a pointer to m_data in the sc_bv_base class,
 // but it is protected.  So make an exposing class, then use
 // cast magic to get at it.  Saves patching get_datap in SystemC.
+// This class is thread safe (though most of SystemC is not).

 #define VL_SC_BV_DATAP(bv) (VlScBvExposer::sp_datap(bv))
 class VlScBvExposer : public sc_bv_base {
 public:
-    static vluint32_t* sp_datap(const sc_bv_base& base) {
-	return static_cast<const VlScBvExposer*>(&base)->sp_datatp(); }
-    vluint32_t* sp_datatp() const { return (vluint32_t*)(m_data); }
+    static const vluint32_t* sp_datap(const sc_bv_base& base) VL_MT_SAFE {
+        return static_cast<const VlScBvExposer*>(&base)->sp_datatp(); }
+    const vluint32_t* sp_datatp() const { return reinterpret_cast<vluint32_t*>(m_data); }
    // Above reads this protected element in sc_bv_base:
    //   sc_digit* m_data; // data array
 };
@@ -1,7 +1,7 @@
 // -*- mode: C++; c-file-style: "cc-mode" -*-
 //*************************************************************************
 //
-// Copyright 2003-2015 by Wilson Snyder. This program is free software; you can
+// Copyright 2003-2017 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.
@@ -20,6 +20,9 @@
 ///	the symbol table.  It is not included in verilated.h
 ///	as it requires some heavyweight C++ classes.
 ///
+///     These classes are thread safe on read only. It is constructed
+///     only when a model is built (from the main thread).
+///
 /// Code available from: http://www.veripool.org/verilator
 ///
 //*************************************************************************
@@ -34,9 +37,10 @@

 //===========================================================================
 /// Verilator range
+/// Thread safety: Assume is constructed only with model, then any number of readers

 // See also V3Ast::VNumRange
-class VerilatedRange { 
+class VerilatedRange {
    int		m_left;
    int		m_right;
 protected:
@@ -53,6 +57,7 @@ public:

 //===========================================================================
 /// Verilator variable
+/// Thread safety: Assume is constructed only with model, then any number of readers

 class VerilatedVar {
    void*		m_datap;	// Location of data
@@ -71,7 +76,7 @@ public:
    ~VerilatedVar() {}
    void* datap() const { return m_datap; }
    VerilatedVarType vltype() const { return m_vltype; }
-    VerilatedVarFlags vldir() const { return (VerilatedVarFlags)((int)m_vlflags & VLVF_MASK_DIR); }
+    VerilatedVarFlags vldir() const { return static_cast<VerilatedVarFlags>(static_cast<int>(m_vlflags) & VLVF_MASK_DIR); }
    vluint32_t entSize() const;
    bool isPublicRW() const { return ((m_vlflags & VLVF_PUB_RW) != 0); }
    const VerilatedRange& range() const { return m_range; }
@@ -91,13 +96,14 @@ struct VerilatedCStrCmp {
 };

 class VerilatedScopeNameMap
-    : public map<const char*, const VerilatedScope*, VerilatedCStrCmp> {
+    : public std::map<const char*, const VerilatedScope*, VerilatedCStrCmp> {
 public:
    VerilatedScopeNameMap() {}
    ~VerilatedScopeNameMap() {}
 };

-class VerilatedVarNameMap : public map<const char*, VerilatedVar, VerilatedCStrCmp> {
+class VerilatedVarNameMap
+    : public std::map<const char*, VerilatedVar, VerilatedCStrCmp> {
 public:
    VerilatedVarNameMap() {}
    ~VerilatedVarNameMap() {}
@@ -3,7 +3,7 @@
 //
 // THIS MODULE IS PUBLICLY LICENSED
 //
-// Copyright 2001-2015 by Wilson Snyder.  This program is free software;
+// Copyright 2001-2017 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.
 //
@@ -47,9 +47,38 @@
 #endif

 //=============================================================================
-// Global
+// VerilatedVcdImp
+/// Base class to hold some static state
+/// This is an internally used class

-vector<VerilatedVcd*>	VerilatedVcd::s_vcdVecp;	///< List of all created traces
+class VerilatedVcdSingleton {
+private:
+    typedef std::vector<VerilatedVcd*> VcdVec;
+    struct Singleton {
+        VerilatedMutex  s_vcdMutex;  ///< Protect the singleton
+        VcdVec          s_vcdVecp VL_GUARDED_BY(s_vcdMutex);  ///< List of all created traces
+    };
+    static Singleton& singleton() { static Singleton s;	return s; }
+public:
+    static void pushVcd(VerilatedVcd* vcdp) VL_EXCLUDES(singleton().s_vcdMutex) {
+	VerilatedLockGuard guard(singleton().s_vcdMutex);
+	singleton().s_vcdVecp.push_back(vcdp);
+    }
+    static void removeVcd(const VerilatedVcd* vcdp) VL_EXCLUDES(singleton().s_vcdMutex) {
+	VerilatedLockGuard guard(singleton().s_vcdMutex);
+	VcdVec::iterator pos = find(singleton().s_vcdVecp.begin(), singleton().s_vcdVecp.end(), vcdp);
+	if (pos != singleton().s_vcdVecp.end()) { singleton().s_vcdVecp.erase(pos); }
+    }
+    static void flush_all() VL_EXCLUDES(singleton().s_vcdMutex) VL_MT_UNSAFE_ONE {
+	// Thread safety: Although this function is protected by a mutex so perhaps
+	// in the future we can allow tracing in separate threads, vcdp->flush() assumes call from single thread
+	VerilatedLockGuard guard(singleton().s_vcdMutex);
+	for (VcdVec::const_iterator it=singleton().s_vcdVecp.begin(); it!=singleton().s_vcdVecp.end(); ++it) {
+	    VerilatedVcd* vcdp = *it;
+	    vcdp->flush();
+	}
+    }
+};

 //=============================================================================
 // VerilatedVcdCallInfo
@@ -67,11 +96,12 @@ protected:
    VerilatedVcdCallback_t	m_changecb;	///< Incremental Dumping Callback function
    void*		m_userthis;	///< Fake "this" for caller
    vluint32_t		m_code;		///< Starting code number
-    // CREATORS
+    // CONSTRUCTORS
    VerilatedVcdCallInfo (VerilatedVcdCallback_t icb, VerilatedVcdCallback_t fcb,
 			  VerilatedVcdCallback_t changecb,
 			  void* ut, vluint32_t code)
 	: m_initcb(icb), m_fullcb(fcb), m_changecb(changecb), m_userthis(ut), m_code(code) {};
+    ~VerilatedVcdCallInfo() {}
 };

 //=============================================================================
@@ -79,16 +109,16 @@ protected:
 //=============================================================================
 // VerilatedVcdFile

-bool VerilatedVcdFile::open(const string& name) {
+bool VerilatedVcdFile::open(const std::string& name) VL_MT_UNSAFE {
    m_fd = ::open(name.c_str(), O_CREAT|O_WRONLY|O_TRUNC|O_LARGEFILE|O_NONBLOCK, 0666);
    return (m_fd>=0);
 }

-void VerilatedVcdFile::close() {
+void VerilatedVcdFile::close() VL_MT_UNSAFE {
    ::close(m_fd);
 }

-ssize_t VerilatedVcdFile::write(const char* bufp, ssize_t len) {
+ssize_t VerilatedVcdFile::write(const char* bufp, ssize_t len) VL_MT_UNSAFE {
    return ::write(m_fd, bufp, len);
 }

@@ -117,11 +147,12 @@ VerilatedVcd::VerilatedVcd(VerilatedVcdFile* filep)
 }

 void VerilatedVcd::open (const char* filename) {
+    m_assertOne.check();
    if (isOpen()) return;

    // Set member variables
    m_filename = filename;
-    s_vcdVecp.push_back(this);
+    VerilatedVcdSingleton::pushVcd(this);

    // SPDIFF_OFF
    // Set callback so an early exit will flush us
@@ -147,10 +178,11 @@ void VerilatedVcd::open (const char* filename) {
 void VerilatedVcd::openNext (bool incFilename) {
    // Open next filename in concat sequence, mangle filename if
    // incFilename is true.
+    m_assertOne.check();
    closePrev(); // Close existing
    if (incFilename) {
 	// Find _0000.{ext} in filename
-	string name = m_filename;
+	std::string name = m_filename;
 	size_t pos=name.rfind(".");
 	if (pos>8 && 0==strncmp("_cat",name.c_str()+pos-8,4)
 	    && isdigit(name.c_str()[pos-4])
@@ -195,7 +227,7 @@ void VerilatedVcd::makeNameMap() {
    m_namemapp = new NameMap;
    for (vluint32_t ent = 0; ent< m_callbacks.size(); ent++) {
 	VerilatedVcdCallInfo *cip = m_callbacks[ent];
-	cip->m_code = nextCode();
+	cip->m_code = m_nextCode;
 	(cip->m_initcb) (this, cip->m_userthis, cip->m_code);
    }

@@ -204,19 +236,19 @@ void VerilatedVcd::makeNameMap() {
    // If no scope was specified, prefix everything with a "top"
    // This comes from user instantiations with no name - IE Vtop("").
    bool nullScope = false;
-    for (NameMap::iterator it=m_namemapp->begin(); it!=m_namemapp->end(); ++it) {
-	const string& hiername = it->first;
+    for (NameMap::const_iterator it=m_namemapp->begin(); it!=m_namemapp->end(); ++it) {
+	const std::string& hiername = it->first;
 	if (hiername.size() >= 1 && hiername[0] == '\t') nullScope=true;
    }
    if (nullScope) {
 	NameMap* newmapp = new NameMap;
-	for (NameMap::iterator it=m_namemapp->begin(); it!=m_namemapp->end(); ++it) {
-	    const string& hiername = it->first;
-	    const string& decl     = it->second;
-	    string newname = string("top");
+	for (NameMap::const_iterator it=m_namemapp->begin(); it!=m_namemapp->end(); ++it) {
+	    const std::string& hiername = it->first;
+	    const std::string& decl     = it->second;
+	    std::string newname = std::string("top");
 	    if (hiername[0] != '\t') newname += ' ';
 	    newname += hiername;
-	    newmapp->insert(make_pair(newname,decl));
+	    newmapp->insert(std::make_pair(newname,decl));
 	}
 	deleteNameMap();
 	m_namemapp = newmapp;
@@ -233,12 +265,15 @@ VerilatedVcd::~VerilatedVcd() {
    if (m_sigs_oldvalp) { delete[] m_sigs_oldvalp; m_sigs_oldvalp=NULL; }
    deleteNameMap();
    if (m_filep && m_fileNewed) { delete m_filep; m_filep = NULL; }
-    // Remove from list of traces
-    vector<VerilatedVcd*>::iterator pos = find(s_vcdVecp.begin(), s_vcdVecp.end(), this);
-    if (pos != s_vcdVecp.end()) { s_vcdVecp.erase(pos); }
+    for (CallbackVec::const_iterator it=m_callbacks.begin(); it!=m_callbacks.end(); ++it) {
+	delete (*it);
+    }
+    m_callbacks.clear();
+    VerilatedVcdSingleton::removeVcd(this);
 }

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

    bufferFlush();
@@ -247,6 +282,7 @@ void VerilatedVcd::closePrev () {
 }

 void VerilatedVcd::closeErr () {
+    // This function is on the flush() call path
    // Close due to an error.  We might abort before even getting here,
    // depending on the definition of vl_fatal.
    if (!isOpen()) return;
@@ -257,6 +293,8 @@ void VerilatedVcd::closeErr () {
 }

 void VerilatedVcd::close() {
+    // This function is on the flush() call path
+    m_assertOne.check();
    if (!isOpen()) return;
    if (m_evcd) {
 	printStr("$vcdclose ");
@@ -285,10 +323,10 @@ void VerilatedVcd::printTime (vluint64_t timeui) {
    // Dinotrace doesn't mind, but Cadence vvision seems to choke
    if (VL_UNLIKELY(timeui < m_timeLastDump)) {
 	timeui = m_timeLastDump;
-	static bool backTime = false;
+	static VL_THREAD_LOCAL bool backTime = false;
 	if (!backTime) {
 	    backTime = true;
-	    VL_PRINTF("VCD time is moving backwards, wave file may be incorrect.\n");
+	    VL_PRINTF_MT("%%Warning: VCD time is moving backwards, wave file may be incorrect.\n");
 	}
    }
    m_timeLastDump = timeui;
@@ -309,10 +347,12 @@ void VerilatedVcd::bufferResize(vluint64_t minsize) {
    }
 }

-void VerilatedVcd::bufferFlush () {
+void VerilatedVcd::bufferFlush () VL_MT_UNSAFE_ONE {
+    // This function is on the flush() call path
    // We add output data to m_writep.
    // When it gets nearly full we dump it using this routine which calls write()
    // This is much faster than using buffered I/O
+    m_assertOne.check();
    if (VL_UNLIKELY(!isOpen())) return;
    char* wp = m_wrBufp;
    while (1) {
@@ -326,8 +366,8 @@ void VerilatedVcd::bufferFlush () {
 	} else if (got < 0) {
 	    if (errno != EAGAIN && errno != EINTR) {
 		// write failed, presume error (perhaps out of disk space)
-		string msg = (string)"VerilatedVcd::bufferFlush: "+strerror(errno);
-		vl_fatal("",0,"",msg.c_str());
+		std::string msg = std::string("VerilatedVcd::bufferFlush: ")+strerror(errno);
+		VL_FATAL_MT("",0,"",msg.c_str());
 		closeErr();
 		break;
 	    }
@@ -354,7 +394,7 @@ void VerilatedVcd::set_time_resolution (const char* unitp) {
 double VerilatedVcd::timescaleToDouble (const char* unitp) {
    char* endp;
    double value = strtod(unitp, &endp);
-    if (!value) value=1;  // On error so we allow just "ns" to return 1e-9.
+    if (value==0.0 && endp==unitp) value=1;  // On error so we allow just "ns" to return 1e-9.
    unitp=endp;
    while (*unitp && isspace(*unitp)) unitp++;
    switch (*unitp) {
@@ -369,7 +409,7 @@ double VerilatedVcd::timescaleToDouble (const char* unitp) {
    return value;
 }

-string VerilatedVcd::doubleToTimescale (double value) {
+std::string VerilatedVcd::doubleToTimescale (double value) {
    const char* suffixp = "s";
    if	    (value>=1e0)   { suffixp="s"; value *= 1e0; }
    else if (value>=1e-3 ) { suffixp="ms"; value *= 1e3; }
@@ -398,7 +438,7 @@ void VerilatedVcd::dumpHeader () {
    printStr("$date "); printStr(ctime(&time_str)); printStr(" $end\n");

    printStr("$timescale ");
-    const string& timeResStr = doubleToTimescale(m_timeRes);
+    const std::string& timeResStr = doubleToTimescale(m_timeRes);
    printStr(timeResStr.c_str());
    printStr(" $end\n");

@@ -412,13 +452,13 @@ void VerilatedVcd::dumpHeader () {
    // We detect the spaces in module names to determine hierarchy.  This
    // allows signals to be declared without fixed ordering, which is
    // required as Verilog signals might be separately declared from
-    // "SP_TRACE" signals.
+    // SC module signals.

    // Print the signal names
    const char* lastName = "";
-    for (NameMap::iterator it=m_namemapp->begin(); it!=m_namemapp->end(); ++it) {
-	const string& hiernamestr = it->first;
-	const string& decl = it->second;
+    for (NameMap::const_iterator it=m_namemapp->begin(); it!=m_namemapp->end(); ++it) {
+	const std::string& hiernamestr = it->first;
+	const std::string& decl = it->second;

 	// Determine difference between the old and new names
 	const char* hiername = hiernamestr.c_str();
@@ -472,20 +512,21 @@ void VerilatedVcd::dumpHeader () {
    deleteNameMap();
 }

-void VerilatedVcd::module (const string& name) {
+void VerilatedVcd::module (const std::string& name) {
+    m_assertOne.check();
    m_modName = name;
 }

 void VerilatedVcd::declare (vluint32_t code, const char* name, const char* wirep,
 			    int arraynum, bool tri, bool bussed, int msb, int lsb) {
-    if (!code) { vl_fatal(__FILE__,__LINE__,"","Internal: internal trace problem, code 0 is illegal"); }
+    if (!code) { VL_FATAL_MT(__FILE__,__LINE__,"","Internal: internal trace problem, code 0 is illegal"); }

    int bits = ((msb>lsb)?(msb-lsb):(lsb-msb))+1;
    int codesNeeded = 1+int(bits/32);
    if (tri) codesNeeded *= 2;   // Space in change array for __en signals

    // Make sure array is large enough
-    m_nextCode = max(nextCode(), code+codesNeeded);
+    m_nextCode = std::max(m_nextCode, code+codesNeeded);
    if (m_sigs.capacity() <= m_nextCode) {
 	m_sigs.reserve(m_nextCode*2);	// Power-of-2 allocation speeds things up
    }
@@ -503,10 +544,10 @@ void VerilatedVcd::declare (vluint32_t code, const char* name, const char* wirep
    // Tab separates final scope from signal name
    // Tab sorts before spaces, so signals nicely will print before scopes
    // Note the hiername may be nothing, if so we'll add "\t{name}"
-    string nameasstr = name;
+    std::string nameasstr = name;
    if (m_modName!="") { nameasstr = m_modName+m_scopeEscape+nameasstr; }  // Optional ->module prefix
-    string hiername;
-    string basename;
+    std::string hiername;
+    std::string basename;
    for (const char* cp=nameasstr.c_str(); *cp; cp++) {
 	if (isScopeEscape(*cp)) {
 	    // Ahh, we've just read a scope, not a basename
@@ -520,7 +561,7 @@ void VerilatedVcd::declare (vluint32_t code, const char* name, const char* wirep
    hiername += "\t"+basename;

    // Print reference
-    string decl = "$var ";
+    std::string decl = "$var ";
    if (m_evcd) decl += "port"; else decl += wirep;  // usually "wire"
    char buf [1000];
    sprintf(buf, " %2d ", bits);
@@ -543,7 +584,7 @@ void VerilatedVcd::declare (vluint32_t code, const char* name, const char* wirep
 	decl += buf;
    }
    decl += " $end\n";
-    m_namemapp->insert(make_pair(hiername,decl));
+    m_namemapp->insert(std::make_pair(hiername,decl));
 }

 void VerilatedVcd::declBit      (vluint32_t code, const char* name, int arraynum)
@@ -570,7 +611,8 @@ void VerilatedVcd::declDouble   (vluint32_t code, const char* name, int arraynum
 //=============================================================================

 void VerilatedVcd::fullDouble (vluint32_t code, const double newval) {
-    (*((double*)&m_sigs_oldvalp[code])) = newval;
+    // cppcheck-suppress invalidPointerCast
+    (*(reinterpret_cast<double*>(&m_sigs_oldvalp[code]))) = newval;
    // Buffer can't overflow before sprintf; we sized during declaration
    sprintf(m_writep, "r%.16g", newval);
    m_writep += strlen(m_writep);
@@ -578,9 +620,10 @@ void VerilatedVcd::fullDouble (vluint32_t code, const double newval) {
    bufferCheck();
 }
 void VerilatedVcd::fullFloat (vluint32_t code, const float newval) {
-    (*((float*)&m_sigs_oldvalp[code])) = newval;
+    // cppcheck-suppress invalidPointerCast
+    (*(reinterpret_cast<float*>(&m_sigs_oldvalp[code]))) = newval;
    // Buffer can't overflow before sprintf; we sized during declaration
-    sprintf(m_writep, "r%.16g", (double)newval);
+    sprintf(m_writep, "r%.16g", static_cast<double>(newval));
    m_writep += strlen(m_writep);
    *m_writep++=' '; printCode(code); *m_writep++='\n';
    bufferCheck();
@@ -589,15 +632,16 @@ void VerilatedVcd::fullFloat (vluint32_t code, const float newval) {
 //=============================================================================
 // Callbacks

-void VerilatedVcd::addCallback (
+void VerilatedVcd::addCallback VL_MT_UNSAFE_ONE (
    VerilatedVcdCallback_t initcb, VerilatedVcdCallback_t fullcb, VerilatedVcdCallback_t changecb,
    void* userthis)
 {
+    m_assertOne.check();
    if (VL_UNLIKELY(isOpen())) {
-	string msg = (string)"Internal: "+__FILE__+"::"+__FUNCTION__+" called with already open file";
-	vl_fatal(__FILE__,__LINE__,"",msg.c_str());
+	std::string msg = std::string("Internal: ")+__FILE__+"::"+__FUNCTION__+" called with already open file";
+	VL_FATAL_MT(__FILE__,__LINE__,"",msg.c_str());
    }
-    VerilatedVcdCallInfo* vci = new VerilatedVcdCallInfo(initcb, fullcb, changecb, userthis, nextCode());
+    VerilatedVcdCallInfo* vci = new VerilatedVcdCallInfo(initcb, fullcb, changecb, userthis, m_nextCode);
    m_callbacks.push_back(vci);
 }

@@ -605,15 +649,17 @@ void VerilatedVcd::addCallback (
 // Dumping

 void VerilatedVcd::dumpFull (vluint64_t timeui) {
+    m_assertOne.check();
    dumpPrep (timeui);
+    Verilated::quiesce();
    for (vluint32_t ent = 0; ent< m_callbacks.size(); ent++) {
 	VerilatedVcdCallInfo *cip = m_callbacks[ent];
 	(cip->m_fullcb) (this, cip->m_userthis, cip->m_code);
    }
-    dumpDone ();
 }

 void VerilatedVcd::dump (vluint64_t timeui) {
+    m_assertOne.check();
    if (!isOpen()) return;
    if (VL_UNLIKELY(m_fullDump)) {
 	m_fullDump = false;	// No need for more full dumps
@@ -625,11 +671,11 @@ void VerilatedVcd::dump (vluint64_t timeui) {
 	if (!isOpen()) return;
    }
    dumpPrep (timeui);
+    Verilated::quiesce();
    for (vluint32_t ent = 0; ent< m_callbacks.size(); ent++) {
 	VerilatedVcdCallInfo *cip = m_callbacks[ent];
 	(cip->m_changecb) (this, cip->m_userthis, cip->m_code);
    }
-    dumpDone();
 }

 void VerilatedVcd::dumpPrep (vluint64_t timeui) {
@@ -638,17 +684,11 @@ void VerilatedVcd::dumpPrep (vluint64_t timeui) {
    printStr("\n");
 }

-void VerilatedVcd::dumpDone () {
-}
-
 //======================================================================
 // Static members

-void VerilatedVcd::flush_all() {
-    for (vluint32_t ent = 0; ent< s_vcdVecp.size(); ent++) {
-	VerilatedVcd* vcdp = s_vcdVecp[ent];
-	vcdp->flush();
-    }
+void VerilatedVcd::flush_all() VL_MT_UNSAFE_ONE {
+    VerilatedVcdSingleton::flush_all();
 }

 //======================================================================
@@ -3,7 +3,7 @@
 //
 // THIS MODULE IS PUBLICLY LICENSED
 //
-// Copyright 2001-2015 by Wilson Snyder.  This program is free software;
+// Copyright 2001-2017 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.
 //
@@ -24,11 +24,11 @@
 #define _VERILATED_VCD_C_H_ 1

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

 #include <string>
 #include <vector>
 #include <map>
-using namespace std;

 class VerilatedVcd;
 class VerilatedVcdCallInfo;
@@ -45,9 +45,9 @@ public:
    // METHODS
    VerilatedVcdFile() : m_fd(0) {}
    virtual ~VerilatedVcdFile() {}
-    virtual bool open(const string& name);
-    virtual void close();
-    virtual ssize_t write(const char* bufp, ssize_t len);
+    virtual bool open(const std::string& name) VL_MT_UNSAFE;
+    virtual void close() VL_MT_UNSAFE;
+    virtual ssize_t write(const char* bufp, ssize_t len) VL_MT_UNSAFE;
 };

 //=============================================================================
@@ -80,13 +80,13 @@ private:
    bool		m_fileNewed;	///< m_filep needs destruction
    bool 		m_isOpen;	///< True indicates open file
    bool		m_evcd;		///< True for evcd format
-    string		m_filename;	///< Filename we're writing to (if open)
+    std::string		m_filename;	///< Filename we're writing to (if open)
    vluint64_t		m_rolloverMB;	///< MB of file size to rollover at
    char		m_scopeEscape;	///< Character to separate scope components
    int			m_modDepth;	///< Depth of module hierarchy
    bool		m_fullDump;	///< True indicates dump ignoring if changed
    vluint32_t		m_nextCode;	///< Next code number to assign
-    string		m_modName;	///< Module name being traced now
+    std::string		m_modName;	///< Module name being traced now
    double		m_timeRes;	///< Time resolution (ns/ms etc)
    double		m_timeUnit;	///< Time units (ns/ms etc)
    vluint64_t		m_timeLastDump;	///< Last time we did a dump
@@ -97,15 +97,18 @@ private:
    vluint64_t		m_wrChunkSize;	///< Output buffer size
    vluint64_t		m_wroteBytes;	///< Number of bytes written to this file

-    vluint32_t*			m_sigs_oldvalp;	///< Pointer to old signal values
-    vector<VerilatedVcdSig>	m_sigs;		///< Pointer to signal information
-    vector<VerilatedVcdCallInfo*>	m_callbacks;	///< Routines to perform dumping
-    typedef map<string,string>	NameMap;
-    NameMap*			m_namemapp;	///< List of names for the header
-    static vector<VerilatedVcd*>	s_vcdVecp;	///< List of all created traces
+    vluint32_t*		m_sigs_oldvalp;	///< Pointer to old signal values
+    typedef std::vector<VerilatedVcdSig>  SigVec;
+    SigVec		m_sigs;		///< Pointer to signal information
+    typedef std::vector<VerilatedVcdCallInfo*>  CallbackVec;
+    CallbackVec		m_callbacks;	///< Routines to perform dumping
+    typedef std::map<std::string,std::string>  NameMap;
+    NameMap*		m_namemapp;	///< List of names for the header
+
+    VerilatedAssertOneThread m_assertOne;  ///< Assert only called from single thread

    void bufferResize(vluint64_t minsize);
-    void bufferFlush();
+    void bufferFlush() VL_MT_UNSAFE_ONE;
    inline void bufferCheck() {
 	// Flush the write buffer if there's not enough space left for new information
 	// We only call this once per vector, so we need enough slop for a very wide "b###" line
@@ -131,33 +134,26 @@ private:
    // cppcheck-suppress functionConst
    void dumpDone ();
    inline void printCode (vluint32_t code) {
-	if (code>=(94*94*94)) *m_writep++ = ((char)((code/94/94/94)%94+33));
-	if (code>=(94*94))    *m_writep++ = ((char)((code/94/94)%94+33));
-	if (code>=(94))       *m_writep++ = ((char)((code/94)%94+33));
-	*m_writep++ = ((char)((code)%94+33));
+	if (code>=(94*94*94)) *m_writep++ = static_cast<char>((code/94/94/94)%94+33);
+	if (code>=(94*94))    *m_writep++ = static_cast<char>((code/94/94)%94+33);
+	if (code>=(94))       *m_writep++ = static_cast<char>((code/94)%94+33);
+	*m_writep++ = static_cast<char>((code)%94+33);
    }
-    static string stringCode (vluint32_t code) {
-	string out;
-	if (code>=(94*94*94)) out += ((char)((code/94/94/94)%94+33));
-	if (code>=(94*94))    out += ((char)((code/94/94)%94+33));
-	if (code>=(94))       out += ((char)((code/94)%94+33));
-	return out + ((char)((code)%94+33));
+    static std::string stringCode (vluint32_t code) VL_PURE {
+	std::string out;
+	if (code>=(94*94*94)) out += static_cast<char>((code/94/94/94)%94+33);
+	if (code>=(94*94))    out += static_cast<char>((code/94/94)%94+33);
+	if (code>=(94))       out += static_cast<char>((code/94)%94+33);
+	return out + static_cast<char>((code)%94+33);
    }

-    VerilatedVcd(const VerilatedVcd& );	///< N/A, no copy constructor
-
-protected:
-    // METHODS
-    void evcd(bool flag) { m_evcd = flag; }
-
+    // CONSTRUCTORS
+    VL_UNCOPYABLE(VerilatedVcd);
 public:
-    // CREATORS
    explicit VerilatedVcd(VerilatedVcdFile* filep=NULL);
    ~VerilatedVcd();

    // ACCESSORS
-    /// Inside dumping routines, return next VCD signal code
-    vluint32_t nextCode() const {return m_nextCode;}
    /// Set size in megabytes after which new file should be created
    void rolloverMB(vluint64_t rolloverMB) { m_rolloverMB=rolloverMB; };
    /// Is file open?
@@ -168,33 +164,35 @@ public:
    inline bool isScopeEscape(char c) { return isspace(c) || c==m_scopeEscape; }

    // METHODS
-    void open (const char* filename);	///< Open the file; call isOpen() to see if errors
+    void open(const char* filename) VL_MT_UNSAFE_ONE;  ///< Open the file; call isOpen() to see if errors
    void openNext (bool incFilename);	///< Open next data-only file
-    void flush() { bufferFlush(); }	///< Flush any remaining data
-    static void flush_all();		///< Flush any remaining data from all files
-    void close ();			///< Close the file
+    void close() VL_MT_UNSAFE_ONE;  ///< Close the file
+    /// Flush any remaining data to this file
+    void flush() VL_MT_UNSAFE_ONE { bufferFlush(); }
+    /// Flush any remaining data from all files
+    static void flush_all() VL_MT_UNSAFE_ONE;

    void set_time_unit (const char* unit); ///< Set time units (s/ms, defaults to ns)
-    void set_time_unit (const string& unit) { set_time_unit(unit.c_str()); }
+    void set_time_unit (const std::string& unit) { set_time_unit(unit.c_str()); }

    void set_time_resolution (const char* unit); ///< Set time resolution (s/ms, defaults to ns)
-    void set_time_resolution (const string& unit) { set_time_resolution(unit.c_str()); }
+    void set_time_resolution (const std::string& unit) { set_time_resolution(unit.c_str()); }

    double timescaleToDouble (const char* unitp);
-    string doubleToTimescale (double value);
+    std::string doubleToTimescale (double value);

    /// Inside dumping routines, called each cycle to make the dump
    void dump     (vluint64_t timeui);
    /// Call dump with a absolute unscaled time in seconds
-    void dumpSeconds (double secs) { dump((vluint64_t)(secs * m_timeRes)); }
+    void dumpSeconds (double secs) { dump(static_cast<vluint64_t>(secs * m_timeRes)); }

    /// Inside dumping routines, declare callbacks for tracings
    void addCallback (VerilatedVcdCallback_t init, VerilatedVcdCallback_t full,
 		      VerilatedVcdCallback_t change,
-		      void* userthis);
+		      void* userthis) VL_MT_UNSAFE_ONE;

    /// Inside dumping routines, declare a module
-    void module (const string& name);
+    void module (const std::string& name);
    /// Inside dumping routines, declare a signal
    void declBit      (vluint32_t code, const char* name, int arraynum);
    void declBus      (vluint32_t code, const char* name, int arraynum, int msb, int lsb);
@@ -212,7 +210,7 @@ public:
    void fullBit (vluint32_t code, const vluint32_t newval) {
 	// Note the &1, so we don't require clean input -- makes more common no change case faster
 	m_sigs_oldvalp[code] = newval;
-	*m_writep++=('0'+(char)(newval&1)); printCode(code); *m_writep++='\n';
+	*m_writep++=('0'+static_cast<char>(newval&1)); printCode(code); *m_writep++='\n';
 	bufferCheck();
    }
    void fullBus (vluint32_t code, const vluint32_t newval, int bits) {
@@ -225,7 +223,7 @@ public:
 	bufferCheck();
    }
    void fullQuad (vluint32_t code, const vluint64_t newval, int bits) {
-	(*((vluint64_t*)&m_sigs_oldvalp[code])) = newval;
+	(*(reinterpret_cast<vluint64_t*>(&m_sigs_oldvalp[code]))) = newval;
 	*m_writep++='b';
 	for (int bit=bits-1; bit>=0; --bit) {
 	    *m_writep++=((newval&(1ULL<<bit))?'1':'0');
@@ -264,8 +262,8 @@ public:
 	bufferCheck();
    }
    void fullTriQuad (vluint32_t code, const vluint64_t newval, const vluint32_t newtri, int bits) {
-	(*((vluint64_t*)&m_sigs_oldvalp[code])) = newval;
-	(*((vluint64_t*)&m_sigs_oldvalp[code+1])) = newtri;
+	(*(reinterpret_cast<vluint64_t*>(&m_sigs_oldvalp[code]))) = newval;
+	(*(reinterpret_cast<vluint64_t*>(&m_sigs_oldvalp[code+1]))) = newtri;
 	*m_writep++='b';
 	for (int bit=bits-1; bit>=0; --bit) {
 	    *m_writep++ = "01zz"[((newval >> bit)&1ULL)
@@ -329,7 +327,7 @@ public:
 	}
    }
    inline void chgQuad (vluint32_t code, const vluint64_t newval, int bits) {
-	vluint64_t diff = (*((vluint64_t*)&m_sigs_oldvalp[code])) ^ newval;
+	vluint64_t diff = (*(reinterpret_cast<vluint64_t*>(&m_sigs_oldvalp[code]))) ^ newval;
 	if (VL_UNLIKELY(diff)) {
 	    if (VL_UNLIKELY(bits==64 || (diff & ((1ULL<<bits)-1) ))) {
 		fullQuad(code, newval, bits);
@@ -364,8 +362,8 @@ public:
 	}
    }
    inline void chgTriQuad (vluint32_t code, const vluint64_t newval, const vluint32_t newtri, int bits) {
-	vluint64_t diff = ( ((*((vluint64_t*)&m_sigs_oldvalp[code])) ^ newval)
-			  | ((*((vluint64_t*)&m_sigs_oldvalp[code+1])) ^ newtri));
+	vluint64_t diff = ( ((*(reinterpret_cast<vluint64_t*>(&m_sigs_oldvalp[code]))) ^ newval)
+			    | ((*(reinterpret_cast<vluint64_t*>(&m_sigs_oldvalp[code+1]))) ^ newtri));
 	if (VL_UNLIKELY(diff)) {
 	    if (VL_UNLIKELY(bits==64 || (diff & ((1ULL<<bits)-1) ))) {
 		fullTriQuad(code, newval, newtri, bits);
@@ -382,27 +380,38 @@ public:
 	}
    }
    inline void chgDouble (vluint32_t code, const double newval) {
-	if (VL_UNLIKELY((*((double*)&m_sigs_oldvalp[code])) != newval)) {
+	// cppcheck-suppress invalidPointerCast
+	if (VL_UNLIKELY((*(reinterpret_cast<double*>(&m_sigs_oldvalp[code]))) != newval)) {
 	    fullDouble (code, newval);
 	}
    }
    inline void chgFloat (vluint32_t code, const float newval) {
-	if (VL_UNLIKELY((*((float*)&m_sigs_oldvalp[code])) != newval)) {
+	// cppcheck-suppress invalidPointerCast
+	if (VL_UNLIKELY((*(reinterpret_cast<float*>(&m_sigs_oldvalp[code]))) != newval)) {
 	    fullFloat (code, newval);
 	}
    }
+
+protected:
+    // METHODS
+    void evcd(bool flag) { m_evcd = flag; }
 };

 //=============================================================================
 // VerilatedVcdC
 /// Create a VCD dump file in C standalone (no SystemC) simulations.
+/// Also derived for use in SystemC simulations.
+/// Thread safety: Unless otherwise indicated, every function is VL_MT_UNSAFE_ONE

 class VerilatedVcdC {
    VerilatedVcd		m_sptrace;	///< Trace file being created
-public:
+
    // CONSTRUCTORS
+    VL_UNCOPYABLE(VerilatedVcdC);
+public:
    explicit VerilatedVcdC(VerilatedVcdFile* filep=NULL) : m_sptrace(filep) {}
    ~VerilatedVcdC() {}
+public:
    // ACCESSORS
    /// Is file open?
    bool isOpen() const { return m_sptrace.isOpen(); }
@@ -410,24 +419,33 @@ public:
    /// Open a new VCD file
    /// This includes a complete header dump each time it is called,
    /// just as if this object was deleted and reconstructed.
-    void open (const char* filename) { m_sptrace.open(filename); }
+    void open(const char* filename) VL_MT_UNSAFE_ONE { m_sptrace.open(filename); }
    /// Continue a VCD dump by rotating to a new file name
    /// The header is only in the first file created, this allows
    /// "cat" to be used to combine the header plus any number of data files.
-    void openNext (bool incFilename=true) { m_sptrace.openNext(incFilename); }
+    void openNext(bool incFilename=true) VL_MT_UNSAFE_ONE { m_sptrace.openNext(incFilename); }
    /// Set size in megabytes after which new file should be created
    void rolloverMB(size_t rolloverMB) { m_sptrace.rolloverMB(rolloverMB); };
    /// Close dump
-    void close() { m_sptrace.close(); }
+    void close() VL_MT_UNSAFE_ONE { m_sptrace.close(); }
    /// Flush dump
-    void flush() { m_sptrace.flush(); }
+    void flush() VL_MT_UNSAFE_ONE { m_sptrace.flush(); }
    /// Write one cycle of dump data
    void dump (vluint64_t timeui) { m_sptrace.dump(timeui); }
    /// Write one cycle of dump data - backward compatible and to reduce
    /// conversion warnings.  It's better to use a vluint64_t time instead.
-    void dump (double timestamp) { dump((vluint64_t)timestamp); }
-    void dump (vluint32_t timestamp) { dump((vluint64_t)timestamp); }
-    void dump (int timestamp) { dump((vluint64_t)timestamp); }
+    void dump (double timestamp) { dump(static_cast<vluint64_t>(timestamp)); }
+    void dump (vluint32_t timestamp) { dump(static_cast<vluint64_t>(timestamp)); }
+    void dump (int timestamp) { dump(static_cast<vluint64_t>(timestamp)); }
+    /// Set time units (s/ms, defaults to ns)
+    /// See also VL_TIME_PRECISION, and VL_TIME_MULTIPLIER in verilated.h
+    void set_time_unit (const char* unit) { m_sptrace.set_time_unit(unit); }
+    void set_time_unit (const std::string& unit) { set_time_unit(unit.c_str()); }
+    /// Set time resolution (s/ms, defaults to ns)
+    /// See also VL_TIME_PRECISION, and VL_TIME_MULTIPLIER in verilated.h
+    void set_time_resolution (const char* unit) { m_sptrace.set_time_resolution(unit); }
+    void set_time_resolution (const std::string& unit) { set_time_resolution(unit.c_str()); }
+
    /// Internal class access
    inline VerilatedVcd* spTrace () { return &m_sptrace; };
 };
@@ -3,7 +3,7 @@
 //
 // THIS MODULE IS PUBLICLY LICENSED
 //
-// Copyright 2001-2015 by Wilson Snyder.  This program is free software;
+// Copyright 2001-2017 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.
 //
@@ -3,7 +3,7 @@
 //
 // THIS MODULE IS PUBLICLY LICENSED
 //
-// Copyright 2001-2015 by Wilson Snyder.  This program is free software;
+// Copyright 2001-2017 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.
 //
@@ -17,6 +17,8 @@
 /// \file
 /// \brief Verilator tracing in VCD format
 ///
+/// This class is not threadsafe, as the SystemC kernel is not threadsafe.
+///
 //=============================================================================
 // SPDIFF_OFF

@@ -37,6 +39,8 @@ class VerilatedVcdSc
    : sc_trace_file
    , public VerilatedVcdC
 {
+    // CONSTRUCTORS
+    VL_UNCOPYABLE(VerilatedVcdSc);
 public:
    VerilatedVcdSc() {
 	sc_get_curr_simcontext()->add_trace_file(this);
@@ -56,8 +60,9 @@ public:
 	spTrace()->set_time_resolution(sc_get_time_resolution().to_string());
 # endif
    }
-
    virtual ~VerilatedVcdSc() {}
+
+    // METHODS
    /// Called by SystemC simulate()
    virtual void cycle (bool delta_cycle) {
 # if (SYSTEMC_VERSION>20011000)
@@ -1,7 +1,7 @@
 // -*- mode: C++; c-file-style: "cc-mode" -*-
 //*************************************************************************
 //
-// Copyright 2009-2015 by Wilson Snyder. This program is free software; you can
+// Copyright 2009-2017 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.
@@ -16,8 +16,8 @@
 /// \file
 /// \brief Verilator: VPI implementation code
 ///
-///	This file must be compiled and linked against all objects
-///	created from Verilator or called by Verilator that use the VPI.
+///     This file must be compiled and linked against all objects
+///     created from Verilator or called by Verilator that use the VPI.
 ///
 /// Code available from: http://www.veripool.org/verilator
 ///
@@ -29,469 +29,24 @@
 #include "verilated.h"
 #include "verilated_syms.h"

-#include <list>
-#include <set>
-#include <map>
-
 //======================================================================
 // From IEEE 1800-2009 annex K

 #include "vltstd/vpi_user.h"

 //======================================================================
-// Internal constants
-
-#define VL_DEBUG_IF_PLI VL_DEBUG_IF
-#define VL_VPI_LINE_SIZE 8192
-
-//======================================================================
-// Internal macros
-
-#define _VL_VPI_INTERNAL    VerilatedVpi::error_info()->setMessage(vpiInternal)->setMessage
-#define _VL_VPI_SYSTEM      VerilatedVpi::error_info()->setMessage(vpiSystem  )->setMessage
-#define _VL_VPI_ERROR       VerilatedVpi::error_info()->setMessage(vpiError   )->setMessage
-#define _VL_VPI_WARNING     VerilatedVpi::error_info()->setMessage(vpiWarning )->setMessage
-#define _VL_VPI_NOTICE      VerilatedVpi::error_info()->setMessage(vpiNotice  )->setMessage
-#define _VL_VPI_ERROR_RESET VerilatedVpi::error_info()->resetError
-
-// Not supported yet
-#define _VL_VPI_UNIMP() \
-    _VL_VPI_ERROR(__FILE__,__LINE__,Verilated::catName("Unsupported VPI function: ",VL_FUNC));
-
-//======================================================================
-// Implementation
-
-// Base VPI handled object
-class VerilatedVpio {
-    // MEM MANGLEMENT
-    static vluint8_t* s_freeHead;
-
-public:
-    // CONSTRUCTORS
-    VerilatedVpio() {}
-    virtual ~VerilatedVpio() {}
-    inline static void* operator new(size_t size) {
-	// We new and delete tons of vpi structures, so keep them around
-	// To simplify our free list, we use a size large enough for all derived types
-	// We reserve word zero for the next pointer, as that's safer in case a
-	// dangling reference to the original remains around.
-	static size_t chunk = 96;
-	if (VL_UNLIKELY(size>chunk)) vl_fatal(__FILE__,__LINE__,"", "increase chunk");
-	if (VL_LIKELY(s_freeHead)) {
-	    vluint8_t* newp = s_freeHead;
-	    s_freeHead = *((vluint8_t**)newp);
-	    return newp+8;
-	} else {
-	    // +8: 8 bytes for next
-	    vluint8_t* newp = (vluint8_t*)(::operator new(chunk+8));
-	    return newp+8;
-	}
-    }
-    inline static void operator delete(void* obj, size_t size) {
-	vluint8_t* oldp = ((vluint8_t*)obj)-8;
-	*((void**)oldp) = s_freeHead;
-	s_freeHead = oldp;
-    }
-    // MEMBERS
-    static inline VerilatedVpio* castp(vpiHandle h) { return dynamic_cast<VerilatedVpio*>((VerilatedVpio*)h); }
-    inline vpiHandle castVpiHandle() { return (vpiHandle)(this); }
-    // ACCESSORS
-    virtual const char* name() { return "<null>"; }
-    virtual const char* fullname() { return "<null>"; }
-    virtual const char* defname() { return "<null>"; }
-    virtual const vluint32_t type() { return 0; }
-    virtual const vluint32_t size() const { return 0; }
-    virtual const VerilatedRange* rangep() const { return NULL; }
-    virtual vpiHandle dovpi_scan() { return 0; }
-};
-
-typedef PLI_INT32 (*VerilatedPliCb)(struct t_cb_data *);
-
-class VerilatedVpioCb : public VerilatedVpio {
-    t_cb_data		m_cbData;
-    s_vpi_value		m_value;
-    QData		m_time;
-public:
-    // cppcheck-suppress uninitVar  // m_value
-    VerilatedVpioCb(const t_cb_data* cbDatap, QData time)
-	: m_cbData(*cbDatap), m_time(time) {
-        m_value.format = cbDatap->value ? cbDatap->value->format : vpiSuppressVal;
-	m_cbData.value = &m_value;
-    }
-    virtual ~VerilatedVpioCb() {}
-    static inline VerilatedVpioCb* castp(vpiHandle h) { return dynamic_cast<VerilatedVpioCb*>((VerilatedVpio*)h); }
-    virtual const vluint32_t type() { return vpiCallback; }
-    vluint32_t reason() const { return m_cbData.reason; }
-    VerilatedPliCb cb_rtnp() const { return m_cbData.cb_rtn; }
-    t_cb_data* cb_datap() { return &(m_cbData); }
-    QData time() const { return m_time; }
-};
-
-class VerilatedVpioConst : public VerilatedVpio {
-    vlsint32_t	m_num;
-public:
-    explicit VerilatedVpioConst(vlsint32_t num) : m_num(num) {}
-    virtual ~VerilatedVpioConst() {}
-    static inline VerilatedVpioConst* castp(vpiHandle h) { return dynamic_cast<VerilatedVpioConst*>((VerilatedVpio*)h); }
-    virtual const vluint32_t type() { return vpiUndefined; }
-    vlsint32_t num() const { return m_num; }
-};
-
-class VerilatedVpioRange : public VerilatedVpio {
-    const VerilatedRange* m_range;
-    vlsint32_t                  m_iteration;
-public:
-    explicit VerilatedVpioRange(const VerilatedRange* range) : m_range(range), m_iteration(0) {}
-    virtual ~VerilatedVpioRange() {}
-    static inline VerilatedVpioRange* castp(vpiHandle h) { return dynamic_cast<VerilatedVpioRange*>((VerilatedVpio*)h); }
-    virtual const vluint32_t type() { return vpiRange; }
-    virtual const vluint32_t size() const { return m_range->elements(); }
-    virtual const VerilatedRange* rangep() const { return m_range; }
-    int iteration() const { return m_iteration; }
-    void iterationInc() { ++m_iteration; }
-    virtual vpiHandle dovpi_scan() {
-	if (!iteration()) {
-	    VerilatedVpioRange* nextp = new VerilatedVpioRange(*this);
-	    nextp->iterationInc();
-	    return ((nextp)->castVpiHandle());
-	} else {
-	    return 0;  // End of list - only one deep
-	}
-    }
-};
-
-class VerilatedVpioScope : public VerilatedVpio {
-    const VerilatedScope*	m_scopep;
-public:
-    explicit VerilatedVpioScope(const VerilatedScope* scopep)
-	: m_scopep(scopep) {}
-    virtual ~VerilatedVpioScope() {}
-    static inline VerilatedVpioScope* castp(vpiHandle h) { return dynamic_cast<VerilatedVpioScope*>((VerilatedVpio*)h); }
-    virtual const vluint32_t type() { return vpiScope; }
-    const VerilatedScope* scopep() const { return m_scopep; }
-    virtual const char* name() { return m_scopep->name(); }
-    virtual const char* fullname() { return m_scopep->name(); }
-};
-
-class VerilatedVpioVar : public VerilatedVpio {
-    const VerilatedVar*		m_varp;
-    const VerilatedScope*	m_scopep;
-    vluint8_t*			m_prevDatap;	// Previous value of data, for cbValueChange
-    union {
-	vluint8_t u8[4];
-	vluint32_t u32;
-    } m_mask;                                   // memoized variable mask
-    vluint32_t			m_entSize;	// memoized variable size
-protected:
-    void*			m_varDatap;	// varp()->datap() adjusted for array entries
-    vlsint32_t			m_index;
-    const VerilatedRange&	get_range() const {
-	// Determine number of dimensions and return outermost
-	return (m_varp->dims()>1) ? m_varp->array() : m_varp->range();
-    }
-public:
-    VerilatedVpioVar(const VerilatedVar* varp, const VerilatedScope* scopep)
-	: m_varp(varp), m_scopep(scopep), m_index(0) {
-	m_prevDatap = NULL;
-	m_mask.u32 = VL_MASK_I(varp->range().elements());
-	m_entSize = varp->entSize();
-	m_varDatap = varp->datap();
-    }
-    virtual ~VerilatedVpioVar() {
-	if (m_prevDatap) { delete [] m_prevDatap; m_prevDatap = NULL; }
-    }
-    static inline VerilatedVpioVar* castp(vpiHandle h) { return dynamic_cast<VerilatedVpioVar*>((VerilatedVpio*)h); }
-    const VerilatedVar* varp() const { return m_varp; }
-    const VerilatedScope* scopep() const { return m_scopep; }
-    vluint32_t mask() const { return m_mask.u32; }
-    vluint8_t mask_byte(int idx) { return m_mask.u8[idx & 3]; }
-    vluint32_t entSize() const { return m_entSize; }
-    const vluint32_t index() { return m_index; }
-    virtual const vluint32_t type() {
-      if (varp()->vldir() != vpiNoDirection) return vpiPort;
-      return (varp()->dims()>1) ? vpiMemory : vpiReg; /* but might be wire, logic */
-    }
-    virtual const vluint32_t size() const { return get_range().elements(); }
-    virtual const VerilatedRange* rangep() const { return &get_range(); }
-    virtual const char* name() { return m_varp->name(); }
-    virtual const char* fullname() {
-	VL_STATIC_OR_THREAD string out;
-	out = string(m_scopep->name())+"."+name();
-	return out.c_str();
-    }
-    void* prevDatap() const { return m_prevDatap; }
-    void* varDatap() const { return m_varDatap; }
-    void createPrevDatap() {
-	if (VL_UNLIKELY(!m_prevDatap)) {
-	    m_prevDatap = new vluint8_t [entSize()];
-	    memcpy(prevDatap(), varp()->datap(), entSize());
-	}
-    }
-};
-
-class VerilatedVpioMemoryWord : public VerilatedVpioVar {
-public:
-    VerilatedVpioMemoryWord(const VerilatedVar* varp, const VerilatedScope* scopep,
-			  vlsint32_t index, int offset)
-	: VerilatedVpioVar(varp, scopep) {
-	m_index = index;
-	m_varDatap = ((vluint8_t*)varp->datap()) + entSize()*offset;
-    }
-    virtual ~VerilatedVpioMemoryWord() {}
-    static inline VerilatedVpioMemoryWord* castp(vpiHandle h) { return dynamic_cast<VerilatedVpioMemoryWord*>((VerilatedVpio*)h); }
-    virtual const vluint32_t type() { return vpiMemoryWord; }
-    virtual const vluint32_t size() const { return varp()->range().elements(); }
-    virtual const VerilatedRange* rangep() const { return &(varp()->range()); }
-    virtual const char* fullname() {
-	VL_STATIC_OR_THREAD string out;
-	char num[20]; sprintf(num,"%d",m_index);
-	out = string(scopep()->name())+"."+name()+"["+num+"]";
-	return out.c_str();
-    }
-};
-
-class VerilatedVpioVarIter : public VerilatedVpio {
-    const VerilatedScope*	m_scopep;
-    VerilatedVarNameMap::iterator m_it;
-    bool m_started;
-public:
-    explicit VerilatedVpioVarIter(const VerilatedScope* scopep)
-	: m_scopep(scopep), m_started(false) {  }
-    virtual ~VerilatedVpioVarIter() {}
-    static inline VerilatedVpioVarIter* castp(vpiHandle h) { return dynamic_cast<VerilatedVpioVarIter*>((VerilatedVpio*)h); }
-    virtual const vluint32_t type() { return vpiIterator; }
-    virtual vpiHandle dovpi_scan() {
-	if (VL_LIKELY(m_scopep->varsp())) {
-	    VerilatedVarNameMap* varsp = m_scopep->varsp();
-	    if (VL_UNLIKELY(!m_started)) { m_it = varsp->begin(); m_started=true; }
-	    else if (VL_UNLIKELY(m_it == varsp->end())) return 0;
-	    else ++m_it;
-	    if (m_it == varsp->end()) return 0;
-	    return ((new VerilatedVpioVar(&(m_it->second), m_scopep))
-		    ->castVpiHandle());
-	} else {
-	    return 0;  // End of list - only one deep
-	}
-    }
-};
-
-class VerilatedVpioMemoryWordIter : public VerilatedVpio {
-    const vpiHandle		m_handle;
-    const VerilatedVar*		m_varp;
-    vlsint32_t                  m_iteration;
-    vlsint32_t                  m_direction;
-    bool                        m_done;
-public:
-    VerilatedVpioMemoryWordIter(const vpiHandle handle, const VerilatedVar* varp)
-	: m_handle(handle), m_varp(varp), m_iteration(varp->array().right()), m_direction(VL_LIKELY(varp->array().left()>varp->array().right())?1:-1), m_done(false) {  }
-    virtual ~VerilatedVpioMemoryWordIter() {}
-    static inline VerilatedVpioMemoryWordIter* castp(vpiHandle h) { return dynamic_cast<VerilatedVpioMemoryWordIter*>((VerilatedVpio*)h); }
-    virtual const vluint32_t type() { return vpiIterator; }
-    void iterationInc() { if (!(m_done = (m_iteration == m_varp->array().left()))) m_iteration+=m_direction; }
-    virtual vpiHandle dovpi_scan() {
-	vpiHandle result;
-	if (m_done) return 0;
-	result = vpi_handle_by_index(m_handle, m_iteration);
-	iterationInc();
-	return result;
-    }
-};
-
-//======================================================================
-
-struct VerilatedVpiTimedCbsCmp {
-    /// Ordering sets keyed by time, then callback descriptor
-    bool operator() (const pair<QData,VerilatedVpioCb*>& a,
-		     const pair<QData,VerilatedVpioCb*>& b) const {
-	if (a.first < b.first) return 1;
-	if (a.first > b.first) return 0;
-	return a.second < b.second;
-    }
-};
-
-class VerilatedVpiError;

 class VerilatedVpi {
-    enum { CB_ENUM_MAX_VALUE = cbAtEndOfSimTime+1 };	// Maxium callback reason
-    typedef list<VerilatedVpioCb*> VpioCbList;
-    typedef set<pair<QData,VerilatedVpioCb*>,VerilatedVpiTimedCbsCmp > VpioTimedCbs;
-
-    struct product_info {
-	PLI_BYTE8* product;
-    };
-
-    VpioCbList		m_cbObjLists[CB_ENUM_MAX_VALUE];	// Callbacks for each supported reason
-    VpioTimedCbs	m_timedCbs;	// Time based callbacks
-    VerilatedVpiError*  m_errorInfop;	// Container for vpi error info
-
-    static VerilatedVpi s_s;		// Singleton
-
 public:
-    VerilatedVpi() { m_errorInfop=NULL; }
-    ~VerilatedVpi() {}
-    static void cbReasonAdd(VerilatedVpioCb* vop) {
-	if (vop->reason() == cbValueChange) {
-	    if (VerilatedVpioVar* varop = VerilatedVpioVar::castp(vop->cb_datap()->obj)) {
-		varop->createPrevDatap();
-	    }
-	}
-	if (VL_UNLIKELY(vop->reason() >= CB_ENUM_MAX_VALUE)) vl_fatal(__FILE__,__LINE__,"", "vpi bb reason too large");
-	s_s.m_cbObjLists[vop->reason()].push_back(vop);
-    }
-    static void cbTimedAdd(VerilatedVpioCb* vop) {
-	s_s.m_timedCbs.insert(make_pair(vop->time(), vop));
-    }
-    static void cbReasonRemove(VerilatedVpioCb* cbp) {
-	VpioCbList& cbObjList = s_s.m_cbObjLists[cbp->reason()];
-	// We do not remove it now as we may be iterating the list,
-	// instead set to NULL and will cleanup later
-	for (VpioCbList::iterator it=cbObjList.begin(); it!=cbObjList.end(); ++it) {
-            if (*it == cbp) *it = NULL;
-	}
-    }
-    static void cbTimedRemove(VerilatedVpioCb* cbp) {
-	VpioTimedCbs::iterator it=s_s.m_timedCbs.find(make_pair(cbp->time(),cbp));
-	if (VL_LIKELY(it != s_s.m_timedCbs.end())) {
-	    s_s.m_timedCbs.erase(it);
-	}
-    }
-    static void callTimedCbs() {
-	QData time = VL_TIME_Q();
-	for (VpioTimedCbs::iterator it=s_s.m_timedCbs.begin(); it!=s_s.m_timedCbs.end(); ) {
-	    if (VL_UNLIKELY(it->first <= time)) {
-		VerilatedVpioCb* vop = it->second;
-		++it;  // iterator may be deleted by callback
-		VL_DEBUG_IF_PLI(VL_PRINTF("-vltVpi:  timed_callback %p\n",vop););
-		(vop->cb_rtnp()) (vop->cb_datap());
-	    }
-	    else { ++it; }
-	}
-    }
-    static QData cbNextDeadline() {
-	VpioTimedCbs::iterator it=s_s.m_timedCbs.begin();
-	if (VL_LIKELY(it!=s_s.m_timedCbs.end())) {
-	    return it->first;
-	} else {
-	    return ~VL_ULL(0);  // maxquad
-	}
-    }
-    static void callCbs(vluint32_t reason) {
-	VpioCbList& cbObjList = s_s.m_cbObjLists[reason];
-	for (VpioCbList::iterator it=cbObjList.begin(); it!=cbObjList.end();) {
-	    if (VL_UNLIKELY(!*it)) { // Deleted earlier, cleanup
-		it = cbObjList.erase(it);
-		continue;
-	    }
-	    VerilatedVpioCb* vop = *it++;
-	    VL_DEBUG_IF_PLI(VL_PRINTF("-vltVpi:  reason_callback %d %p\n",reason,vop););
-	    (vop->cb_rtnp()) (vop->cb_datap());
-	}
-    }
-    static void callValueCbs() {
-	VpioCbList& cbObjList = s_s.m_cbObjLists[cbValueChange];
-        set<VerilatedVpioVar*> update; // set of objects to update after callbacks
-	for (VpioCbList::iterator it=cbObjList.begin(); it!=cbObjList.end();) {
-	    if (VL_UNLIKELY(!*it)) { // Deleted earlier, cleanup
-		it = cbObjList.erase(it);
-		continue;
-	    }
-	    VerilatedVpioCb* vop = *it++;
-	    if (VerilatedVpioVar* varop = VerilatedVpioVar::castp(vop->cb_datap()->obj)) {
-		void* newDatap = varop->varDatap();
-		void* prevDatap = varop->prevDatap();  // Was malloced when we added the callback
-		VL_DEBUG_IF_PLI(VL_PRINTF("-vltVpi:  value_test %s v[0]=%d/%d %p %p\n",
-					  varop->fullname(), *((CData*)newDatap), *((CData*)prevDatap),
-					  newDatap, prevDatap););
-		if (memcmp(prevDatap, newDatap, varop->entSize())) {
-		    VL_DEBUG_IF_PLI(VL_PRINTF("-vltVpi:  value_callback %p %s v[0]=%d\n",
-					      vop,varop->fullname(), *((CData*)newDatap)););
-                    update.insert(varop);
-		    vpi_get_value(vop->cb_datap()->obj, vop->cb_datap()->value);
-		    (vop->cb_rtnp()) (vop->cb_datap());
-		}
-	    }
-	}
-	for (set<VerilatedVpioVar*>::iterator it=update.begin(); it!=update.end(); ++it) {
-	    memcpy((*it)->prevDatap(), (*it)->varDatap(), (*it)->entSize());
-	}
-    }
-
-    static VerilatedVpiError* error_info(); // getter for vpi error info
+    /// Call timed callbacks
+    /// Users should call this from their main loops
+    static void callTimedCbs() VL_MT_UNSAFE_ONE;
+    /// Call value based callbacks
+    /// Users should call this from their main loops
+    static void callValueCbs() VL_MT_UNSAFE_ONE;
+    /// Self test, for internal use only
+    static void selfTest() VL_MT_UNSAFE_ONE;
 };

-#define _VL_VPI_ERROR_SET \
-    do { \
-        va_list args; \
-        va_start(args, message); \
-        VL_VSNPRINTF(m_buff, sizeof(m_buff), message.c_str(), args); \
-        va_end(args); \
-    } while (0)
-
-class VerilatedVpiError {
-    //// Container for vpi error info
-
-    t_vpi_error_info m_errorInfo;
-    bool             m_flag;
-    char             m_buff[VL_VPI_LINE_SIZE];
-    void setError(PLI_BYTE8 *message, PLI_BYTE8 *code, PLI_BYTE8 *file, PLI_INT32 line) {
-	m_errorInfo.message = message;
-	m_errorInfo.file = file;
-	m_errorInfo.line = line;
-	m_errorInfo.code = code;
-	do_callbacks();
-    }
-    void do_callbacks() {
-        if (getError()->level >= vpiError && Verilated::fatalOnVpiError()) {
-          // Stop on vpi error/unsupported
-          vpi_unsupported();
-	}
-        // We need to run above code first because in the case that the callback executes further vpi
-        // functions we will loose the error as it will be overwritten.
-	VerilatedVpi::callCbs(cbPLIError);
-    }
-public:
-
-    VerilatedVpiError() : m_flag(false) {
-	m_buff[0] = '\0';
-	m_errorInfo.product = (PLI_BYTE8*)Verilated::productName();
-    }
-    ~VerilatedVpiError() {}
-    static void selfTest();
-    VerilatedVpiError* setMessage(PLI_INT32 level) {
-	m_flag=true;
-	m_errorInfo.level = level;
-        return this;
-    }
-    void setMessage(string file, PLI_INT32 line, string message, ...) {
-	static VL_THREAD string filehold;
-        _VL_VPI_ERROR_SET;
-        m_errorInfo.state = vpiPLI;
-	filehold = file;
-        setError((PLI_BYTE8*)m_buff, NULL, (PLI_BYTE8*)filehold.c_str(), line);
-    }
-    p_vpi_error_info getError() {
-	if (m_flag) return &m_errorInfo;
-	return NULL;
-    }
-    void resetError() {
-	m_flag=false;
-    }
-    static void vpi_unsupported() {
-	// Not supported yet
-	p_vpi_error_info error_info_p = VerilatedVpi::error_info()->getError();
-	if (error_info_p) {
-	    vl_fatal(error_info_p->file, error_info_p->line, "", error_info_p->message);
-	    return;
-	}
-        vl_fatal(__FILE__, __LINE__, "", "vpi_unsupported called without error info set");
-    }
-    static const char* strFromVpiVal(PLI_INT32 vpiVal);
-    static const char* strFromVpiObjType(PLI_INT32 vpiVal);
-    static const char* strFromVpiMethod(PLI_INT32 vpiVal);
-    static const char* strFromVpiCallbackReason(PLI_INT32 vpiVal);
-    static const char* strFromVpiProp(PLI_INT32 vpiVal);
-};
-
-//======================================================================

 #endif // Guard
@@ -1,7 +1,7 @@
 // -*- mode: C++; c-file-style: "cc-mode" -*-
 //*************************************************************************
 //
-// Copyright 2003-2015 by Wilson Snyder. This program is free software; you can
+// Copyright 2003-2017 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.
@@ -42,49 +42,100 @@
 # else
 #  define VL_ATTR_PRINTF(fmtArgNum) __attribute__ ((format (printf, fmtArgNum, fmtArgNum+1)))
 # endif
+# define VL_ATTR_PURE __attribute__ ((pure))
 # define VL_ATTR_UNUSED __attribute__ ((unused))
 # define VL_FUNC  __func__
+# if defined(__clang__) && defined(VL_THREADED)
+#  define VL_ACQUIRE(...) __attribute__ ((acquire_capability(__VA_ARGS__)))
+#  define VL_ACQUIRE_SHARED(...) __attribute__ ((acquire_shared_capability(__VA_ARGS__)))
+#  define VL_RELEASE(...) __attribute__ ((release_capability(__VA_ARGS__)))
+#  define VL_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__ ((requires_capability(x)))
+#  define VL_GUARDED_BY(x) __attribute__ ((guarded_by(x)))
+#  define VL_EXCLUDES(x) __attribute__ ((locks_excluded(x)))
+#  define VL_SCOPED_CAPABILITY __attribute__ ((scoped_lockable))
+# endif
 # define VL_LIKELY(x)	__builtin_expect(!!(x), 1)
 # define VL_UNLIKELY(x)	__builtin_expect(!!(x), 0)
+# define VL_UNREACHABLE __builtin_unreachable();
 # define VL_PREFETCH_RD(p) __builtin_prefetch((p),0)
 # define VL_PREFETCH_RW(p) __builtin_prefetch((p),1)
 #elif defined(_MSC_VER)
-# define VL_ATTR_ALIGNED(alignment)
-# define VL_ATTR_ALWINLINE
-# define VL_ATTR_NORETURN
-# define VL_ATTR_PRINTF(fmtArgNum)
-# define VL_ATTR_UNUSED
 # define VL_FUNC  __FUNCTION__
-# define VL_LIKELY(x)	(!!(x))
-# define VL_UNLIKELY(x)	(!!(x))
-# define VL_PREFETCH_RD(p)
-# define VL_PREFETCH_RW(p)
-#else
+#endif
+
+// Defaults for unsupported compiler features
+#ifndef VL_ATTR_ALIGNED
 # define VL_ATTR_ALIGNED(alignment)	///< Align structure to specified byte alignment
+#endif
+#ifndef VL_ATTR_ALWINLINE
 # define VL_ATTR_ALWINLINE		///< Inline, even when not optimizing
+#endif
+#ifndef VL_ATTR_NORETURN
 # define VL_ATTR_NORETURN		///< Function does not ever return
+#endif
+#ifndef VL_ATTR_PRINTF
 # define VL_ATTR_PRINTF(fmtArgNum)	///< Function with printf format checking
+#endif
+#ifndef VL_ATTR_PURE
+# define VL_ATTR_PURE			///< Function is pure (and thus also VL_MT_SAFE)
+#endif
+#ifndef VL_ATTR_UNUSED
 # define VL_ATTR_UNUSED			///< Function that may be never used
+#endif
+#ifndef VL_FUNC
 # define VL_FUNC "__func__"		///< Name of current function for error macros
+#endif
+#ifndef VL_CAPABILITY
+# define VL_ACQUIRE(...)		///< Function requires a capability/lock (-fthread-safety)
+# define VL_ACQUIRE_SHARED(...)		///< Function aquires 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 aquired a capability (-fthread-safety)
+# define VL_TRY_ACQUIRE_SHARED(...)	///< Function returns bool if aquired a shared capability (-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))		///< Boolean expression more often true than false
 # define VL_UNLIKELY(x)	(!!(x))		///< Boolean expression more often false than true
+#endif
+#ifndef VL_UNREACHABLE
+# define VL_UNREACHABLE			///< Point that may never be reached
+#endif
+#ifndef VL_PREFETCH_RD
 # define VL_PREFETCH_RD(p)		///< Prefetch data with read intent
+#endif
+#ifndef VL_PREFETCH_RW
 # define VL_PREFETCH_RW(p)		///< Prefetch data with read/write intent
 #endif

 #ifdef VL_THREADED
 # ifdef __GNUC__
-#  define VL_THREAD	__thread	///< Storage class for thread-local storage
+#  if (__cplusplus < 201103L) && !defined(VL_THREADED_NO_C11_WARNING)
+#    error "VL_THREADED/--threads support requires C++-11 or newer only; use newer compiler"
+#  endif
 # else
 #  error "Unsupported compiler for VL_THREADED: No thread-local declarator"
 # endif
-# define VL_STATIC_OR_THREAD		///< Static if unthreaded, as some strings can be faster
-//					///< if non-dynamic and can't do "static VL_THREAD string"
+# define VL_THREAD_LOCAL thread_local	///< Use new C++ static local thread
 #else
-# define VL_THREAD			///< Storage class for thread-local storage
-# define VL_STATIC_OR_THREAD static	///< Static if unthreaded, as some strings can be faster
-//					///< if non-dynamic and can't do "static VL_THREAD string"
+# define VL_THREAD_LOCAL		///< Use new C++ static local thread
 #endif
+#define VL_THREAD			///< Deprecated
+#define VL_STATIC_OR_THREAD static	///< Deprecated
+
+#define VL_PURE  ///< Comment tag that Function is pure (and thus also VL_MT_SAFE)
+#define VL_MT_SAFE  ///< Comment tag that function is threadsafe when VL_THREADED
+#define VL_MT_SAFE_POSTINIT  ///< Comment tag that function is threadsafe when VL_THREADED, only during normal operation (post-init)
+#define VL_MT_UNSAFE  ///< Comment tag that function is not threadsafe when VL_THREADED
+#define VL_MT_UNSAFE_ONE  ///< Comment tag that function is not threadsafe when VL_THREADED, protected to make sure single-caller

 #ifdef _MSC_VER
 # define VL_ULL(c) (c##ui64)	///< Add appropriate suffix to 64-bit constant
@@ -93,9 +144,9 @@
 #endif

 // This is not necessarily the same as #UL, depending on what the IData typedef is.
-#define VL_UL(c) ((IData)(c##UL))	///< Add appropriate suffix to 32-bit constant
+#define VL_UL(c) (static_cast<IData>(c##UL))	///< Add appropriate suffix to 32-bit constant

-#ifdef VL_CPPCHECK
+#if defined(VL_CPPCHECK) || defined(__clang_analyzer__)
 # define VL_DANGLING(v)
 #else
 # define VL_DANGLING(v) do { (v) = NULL; } while(0)	///< After e.g. delete, set variable to NULL to indicate must not use later
@@ -105,10 +156,22 @@
 // C++-2011

 #if __cplusplus >= 201103L || defined(__GXX_EXPERIMENTAL_CXX0X__)
+# define VL_EQ_DELETE = delete
 # define VL_HAS_UNIQUE_PTR
-# define VL_UNIQUE_PTR unique_ptr
+# define VL_HAS_UNORDERED_MAP
+# define VL_HAS_UNORDERED_SET
+# define vl_unique_ptr std::unique_ptr
+# define vl_unordered_map std::unordered_map
+# define vl_unordered_set std::unordered_set
+# define VL_INCLUDE_UNORDERED_MAP <unordered_map>
+# define VL_INCLUDE_UNORDERED_SET <unordered_set>
 #else
-# define VL_UNIQUE_PTR auto_ptr
+# define VL_EQ_DELETE
+# define vl_unique_ptr std::auto_ptr
+# define vl_unordered_map std::map
+# define vl_unordered_set std::set
+# define VL_INCLUDE_UNORDERED_MAP <map>
+# define VL_INCLUDE_UNORDERED_SET <set>
 #endif

 //=========================================================================
@@ -248,6 +311,14 @@ typedef unsigned long long	vluint64_t;	///< 64-bit unsigned type
 /// Words this number of bits needs (1 bit=1 word)
 #define VL_WORDS_I(nbits) (((nbits)+(VL_WORDSIZE-1))/VL_WORDSIZE)

+//=========================================================================
+// Class definition helpers
+
+// Used to declare a class as uncopyable; put after a private:
+#define VL_UNCOPYABLE(Type)  \
+    Type(const Type& other) VL_EQ_DELETE;  \
+    Type& operator= (const Type&) VL_EQ_DELETE
+
 //=========================================================================
 // Verilated function size macros

@@ -105,10 +105,12 @@ typedef unsigned char    PLI_UBYTE8;

 /* object is defined imported by the application */

+#undef XXTERN
 #define XXTERN PLI_EXTERN PLI_DLLISPEC

 /* object is exported by the application */

+#undef EETERN
 #define EETERN PLI_EXTERN PLI_DLLESPEC
 #endif

@@ -124,7 +124,7 @@ if [ x"$dir_arg" != x ]; then
 else

 # Waiting for this to be detected by the "$instcmd $src $dsttmp" command
-# might cause directories to be created, which would be especially bad 
+# might cause directories to be created, which would be especially bad
 # if $src (and thus $dsttmp) contains '*'.

 	if [ -f $src -o -d $src ]
@@ -134,7 +134,7 @@ else
 		echo "install:  $src does not exist"
 		exit 1
 	fi
-	
+
 	if [ x"$dst" = x ]
 	then
 		echo "install:	no destination specified"
@@ -162,7 +162,7 @@ dstdir=`echo $dst | sed -e 's,[^/]*$,,;s,/$,,;s,^$,.,'`

 # Skip lots of stat calls in the usual case.
 if [ ! -d "$dstdir" ]; then
-defaultIFS='	
+defaultIFS='
 '
 IFS="${IFS-${defaultIFS}}"

@@ -201,17 +201,17 @@ else

 # If we're going to rename the final executable, determine the name now.

-	if [ x"$transformarg" = x ] 
+	if [ x"$transformarg" = x ]
 	then
 		dstfile=`basename $dst`
 	else
-		dstfile=`basename $dst $transformbasename | 
+		dstfile=`basename $dst $transformbasename |
 			sed $transformarg`$transformbasename
 	fi

 # don't allow the sed command to completely eliminate the filename

-	if [ x"$dstfile" = x ] 
+	if [ x"$dstfile" = x ]
 	then
 		dstfile=`basename $dst`
 	else
@@ -242,7 +242,7 @@ else
 # Now rename the file to the real destination.

 	$doit $rmcmd -f $dstdir/$dstfile &&
-	$doit $mvcmd $dsttmp $dstdir/$dstfile 
+	$doit $mvcmd $dsttmp $dstdir/$dstfile

 fi &&

@@ -237,10 +237,10 @@ implementation is not found, the system will look in turn for overloaded
 implementations up the inheritance hierarchy. For example calling C<accept>
 on C<AstIf> will look in turn for:

-  void visit (AstIf* nodep, AstNUser* vup)
-  void visit (AstNodeIf* nodep, AstNUser* vup)
-  void visit (AstNodeStmt* nodep, AstNUser* vup)
-  void visit (AstNode* nodep, AstNUser* vup)
+  void visit (AstIf* nodep)
+  void visit (AstNodeIf* nodep)
+  void visit (AstNodeStmt* nodep)
+  void visit (AstNode* nodep)

 There are three ways data is passed between visitor functions.

@@ -485,10 +485,10 @@ be warning free.

 =item --enable-longtests

-In addition to the standard C, SystemC tests also run the tests in the
-C<test_verilated> and C<test_regress> directories when using I<make test>.
-This is disabled by default as SystemC installation problems would
-otherwise falsely indicate a Verilator problem.
+In addition to the standard C, SystemC examples, also run the tests in the
+C<test_regress> directory when using I<make test>.  This is disabled by
+default as SystemC installation problems would otherwise falsely indicate a
+Verilator problem.

 =back

@@ -709,7 +709,7 @@ Start GDB, then C<start> with the remaining arguments.
  Temporary breakpoint 1, main (argc=13, argv=0xbfffefa4, env=0xbfffefdc)
      at ../Verilator.cpp:615
  615         ios::sync_with_stdio();
-  (gdb) 
+  (gdb)

 You can then continue execution with breakpoints as required.

@@ -785,7 +785,7 @@ in C<src/Makefile_obj.in> and reconfigure.

 The latest version is available from L<http://www.veripool.org/>.

-Copyright 2008-2015 by Wilson Snyder.  Verilator is free software; you can
+Copyright 2008-2017 by Wilson Snyder.  Verilator 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.

@@ -1,7 +1,7 @@
 #!/usr/bin/perl -w
 ######################################################################
 #
-# Copyright 2007-2015 by Wilson Snyder.  This package is free software; you
+# Copyright 2007-2017 by Wilson Snyder.  This package 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.
@@ -1,7 +1,7 @@
 #!/usr/bin/perl -w
 ######################################################################
 #
-# Copyright 2007-2015 by Wilson Snyder.  This package is free software; you
+# Copyright 2007-2017 by Wilson Snyder.  This package 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.
@@ -143,7 +143,7 @@ Displays this message and program version and exits.

 =head1 DISTRIBUTION

-Copyright 2005-2015 by Wilson Snyder.  Verilator is free software; you can
+Copyright 2005-2017 by Wilson Snyder.  Verilator 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.

@@ -184,7 +184,7 @@ Displays this message and program version and exits.

 =head1 DISTRIBUTION

-Copyright 2005-2015 by Wilson Snyder.  Verilator is free software; you can
+Copyright 2005-2017 by Wilson Snyder.  Verilator 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.

@@ -1,7 +1,7 @@
 #!/usr/bin/perl -w
 ######################################################################
 #
-# Copyright 2007-2015 by Wilson Snyder.  This package is free software; you
+# Copyright 2007-2017 by Wilson Snyder.  This package 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.
@@ -115,7 +115,8 @@ sub write_verilog {

 sub cleanenv {
    foreach my $var (keys %ENV) {
-	if ($var eq "VERILATOR_ROOT") {
+	if ($var eq "VERILATOR_ROOT"
+	    || $var eq "VERILATOR_INCLUDE") {
 	    print "unset $var # Was '$ENV{$var}'\n";
 	    delete $ENV{$var}
 	}
@@ -183,7 +184,7 @@ Runs a specific test stage (see the script).

 =head1 DISTRIBUTION

-Copyright 2009-2015 by Wilson Snyder.  This package is free software; you
+Copyright 2009-2017 by Wilson Snyder.  This package 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.
@@ -28,7 +28,7 @@ invoke_atsim - Invoke tool under "modules" command

 =head1 DISTRIBUTION

-Copyright 2005-2015 by Wilson Snyder.  This package is free software; you
+Copyright 2005-2017 by Wilson Snyder.  This package 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.
@@ -28,7 +28,7 @@ invoke_iccr - Invoke tool under "modules" command

 =head1 DISTRIBUTION

-Copyright 2007-2015 by Wilson Snyder.  This package is free software; you
+Copyright 2007-2017 by Wilson Snyder.  This package 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.
@@ -28,7 +28,7 @@ invoke_ncverilog - Invoke tool under "modules" command

 =head1 DISTRIBUTION

-Copyright 2005-2015 by Wilson Snyder.  This package is free software; you
+Copyright 2005-2017 by Wilson Snyder.  This package 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.
@@ -8,7 +8,7 @@ use strict;
 #======================================================================
 # main

-eval `modulecmd perl add synopsys-vcs_mx`;
+eval `modulecmd perl add synopsys-sim`;
 exec('vcs',@ARGV);

 #######################################################################
@@ -28,7 +28,7 @@ invoke_vcs - Invoke tool under "modules" command

 =head1 DISTRIBUTION

-Copyright 2005-2015 by Wilson Snyder.  This package is free software; you
+Copyright 2005-2017 by Wilson Snyder.  This package 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.
@@ -331,7 +331,7 @@ Displays this message and program version and exits.

 =head1 DISTRIBUTION

-Copyright 2005-2015 by Wilson Snyder.  Verilator is free software; you can
+Copyright 2005-2017 by Wilson Snyder.  Verilator 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.

@@ -1,6 +1,6 @@
 # DESCRIPTION: Verilator: GDB startup file with useful defines
 #
-# Copyright 2012-2015 by Wilson Snyder. This program is free software; you can
+# Copyright 2012-2017 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.
@@ -7,7 +7,7 @@
 #
 #*****************************************************************************
 #
-# Copyright 2003-2015 by Wilson Snyder.  This program is free software; you can
+# Copyright 2003-2017 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.
@@ -46,25 +46,27 @@ obj_opt:
 obj_dbg:
 	mkdir $@

-.PHONY: ../verilator_bin ../verilator_bin_dbg ../verilator_coverage_bin_dbg
+.SUFFIXES:

-opt: ../verilator_bin
+.PHONY: ../bin/verilator_bin ../bin/verilator_bin_dbg ../bin/verilator_coverage_bin_dbg
+
+opt: ../bin/verilator_bin
 ifeq ($(VERILATOR_NO_OPT_BUILD),1)	# Faster laptop development... One build
-../verilator_bin: ../verilator_bin_dbg
+../bin/verilator_bin: ../bin/verilator_bin_dbg
 	-rm -rf $@ $@.exe
 	-cp -p $<$(EXEEXT) $@$(EXEEXT)
 else
-../verilator_bin: obj_opt prefiles
+../bin/verilator_bin: obj_opt prefiles
 	cd obj_opt && $(MAKE) -j 1  TGT=../$@ -f ../Makefile_obj serial
 	cd obj_opt && $(MAKE)       TGT=../$@ -f ../Makefile_obj
 endif

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

-../verilator_coverage_bin_dbg: obj_dbg prefiles
+../bin/verilator_coverage_bin_dbg: obj_dbg prefiles
 	cd obj_dbg && $(MAKE)       TGT=../$@ VL_DEBUG=1 VL_VLCOV=1 -f ../Makefile_obj serial_vlcov
 	cd obj_dbg && $(MAKE)       TGT=../$@ VL_DEBUG=1 VL_VLCOV=1 -f ../Makefile_obj

@@ -7,7 +7,7 @@
 #
 #*****************************************************************************
 #
-# Copyright 2003-2015 by Wilson Snyder.  This program is free software; you can
+# Copyright 2003-2017 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.
@@ -64,6 +64,8 @@ LDFLAGS += @LDFLAGS@
 EXEEXT = @EXEEXT@
 CFG_CXXFLAGS_SRC = @CFG_CXXFLAGS_SRC@
 CFG_CXXFLAGS_PARSER = @CFG_CXXFLAGS_PARSER@
+# Compiler flags that turn on extra warnings
+CFG_CXXFLAGS_WEXTRA = @CFG_CXXFLAGS_WEXTRA@

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

@@ -73,7 +75,7 @@ TGT = ../../verilator_bin
 #################
 ifeq ($(VL_DEBUG),)
 # Optimize
-COPT = -O
+COPT = -O2
 else
 # Debug
 COPT = -ggdb -DVL_DEBUG
@@ -97,18 +99,15 @@ CPPFLAGS += -DYYDEBUG 	# Required to get nice error messages
 CPPFLAGS += $(COPT)
 CPPFLAGS += -MP # Only works on recent GCC versions
 ifeq ($(CFG_WITH_CCWARN),yes)	# Local... Else don't burden users
-CPPFLAGS += -W -Wall $(CFG_CXXFLAGS_SRC) -Werror
+CPPFLAGS += -W -Wall $(CFG_CXXFLAGS_WEXTRA) $(CFG_CXXFLAGS_SRC) -Werror
 #CPPFLAGS += -pedantic-errors
+else
+CPPFLAGS += $(CFG_CXXFLAGS_SRC)
 endif
+
 CPPFLAGSWALL   = $(CPPFLAGS)
 CPPFLAGSPARSER = $(CPPFLAGS) $(CFG_CXXFLAGS_PARSER)

-ifneq ($(SYSTEMPERL),)	# Intuit SYSTEMPERL_INCLUDE as it's new
- SYSTEMPERL_INCLUDE ?= $(SYSTEMPERL)/src
-#else if set, leave as-is.
-#else if SYSTEMPERL="" don't set _INCLUDE so source will figure it out
-endif
-
 # Allow RPM builds to specify hardcoded data directories
 # To do this:
 ifeq ($(CFG_WITH_DEFENV),yes)
@@ -116,8 +115,6 @@ ifeq ($(CFG_WITH_DEFENV),yes)
 CPPFLAGS += -DDEFENV_SYSTEMC_ARCH=\"$(SYSTEMC_ARCH)\"
 CPPFLAGS += -DDEFENV_SYSTEMC_INCLUDE=\"$(SYSTEMC_INCLUDE)\"
 CPPFLAGS += -DDEFENV_SYSTEMC_LIBDIR=\"$(SYSTEMC_LIBDIR)\"
- CPPFLAGS += -DDEFENV_SYSTEMPERL=\"$(SYSTEMPERL)\"
- CPPFLAGS += -DDEFENV_SYSTEMPERL_INCLUDE=\"$(SYSTEMPERL_INCLUDE)\"
 ifeq ($(VERILATOR_ROOT),)	# Use what we're given, or intuit
  CPPFLAGS += -DDEFENV_VERILATOR_ROOT=\"$(pkgdatadir)\"
 else
@@ -164,6 +161,7 @@ RAW_OBJS = \
 	V3Begin.o \
 	V3Branch.o \
 	V3Broken.o \
+	V3CCtors.o \
 	V3Case.o \
 	V3Cast.o \
 	V3Cdc.o \
@@ -299,7 +297,7 @@ serial:: V3Ast__gen_classes.h V3ParseBison.c

 serial_vlcov:: vlcovgen.d

-vlcovgen.d: $(VLCOVGEN) $(srcdir)/include/verilated_cov_key.h
+vlcovgen.d: $(VLCOVGEN) $(srcdir)/../include/verilated_cov_key.h
 	$(PERL) $(VLCOVGEN) --srcdir $(srcdir)
 	touch $@

@@ -327,6 +325,8 @@ V3PreLex_pregen.yy.cpp:	V3PreLex.l $(HEADERS)
 V3PreLex.yy.cpp: V3PreLex_pregen.yy.cpp $(FLEXFIX)
 	$(PERL) $(FLEXFIX) V3PreLex <$< >$@

+.SUFFIXES:
+
 ######################################################################
 ######################################################################

@@ -6,7 +6,7 @@
 //
 //*************************************************************************
 //
-// Copyright 2003-2015 by Wilson Snyder.  This program is free software; you can
+// Copyright 2003-2017 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.
@@ -73,7 +73,7 @@ private:
 	m_scopep->addActivep(nodep);
    }
    // VISITORS
-    virtual void visit(AstScope* nodep, AstNUser*) {
+    virtual void visit(AstScope* nodep) {
 	m_scopep = nodep;
 	m_iActivep = NULL;
 	m_cActivep = NULL;
@@ -81,15 +81,15 @@ private:
 	nodep->iterateChildren(*this);
 	// Don't clear scopep, the namer persists beyond this visit
    }
-    virtual void visit(AstSenTree* nodep, AstNUser*) {
+    virtual void visit(AstSenTree* nodep) {
 	// Simplify sensitivity list
 	V3Const::constifyExpensiveEdit(nodep); VL_DANGLING(nodep);
    }
    // Empty visitors, speed things up
-    virtual void visit(AstNodeStmt* nodep, AstNUser*) { }
+    virtual void visit(AstNodeStmt* nodep) { }
    //--------------------
    // Default
-    virtual void visit(AstNode* nodep, AstNUser*) {
+    virtual void visit(AstNode* nodep) {
 	// Default: Just iterate
 	nodep->iterateChildren(*this);
    }
@@ -169,14 +169,14 @@ private:
    AstNode*	m_alwaysp;	// Always we're under
    AstNode*	m_assignp;	// In assign
    // VISITORS
-    virtual void visit(AstAssignDly* nodep, AstNUser*) {
+    virtual void visit(AstAssignDly* nodep) {
 	if (m_check != CT_SEQ) {
 	    // Convert to a non-delayed assignment
 	    UINFO(5,"    ASSIGNDLY "<<nodep<<endl);
 	    if (m_check == CT_INITIAL) {
 		nodep->v3warn(INITIALDLY,"Delayed assignments (<=) in initial or final block; suggest blocking assignments (=).");
 	    } else if (m_check == CT_LATCH) {
-		// Suppress. Shouldn't matter that the interior of the latch races 
+		// Suppress. Shouldn't matter that the interior of the latch races
 	    } else {
 		nodep->v3warn(COMBDLY,"Delayed assignments (<=) in non-clocked (non flop or latch) block; suggest blocking assignments (=).");
 	    }
@@ -187,7 +187,7 @@ private:
 	    nodep->deleteTree(); VL_DANGLING(nodep);
 	}
    }
-    virtual void visit(AstAssign* nodep, AstNUser*) {
+    virtual void visit(AstAssign* nodep) {
 	if (m_check == CT_SEQ) {
 	    AstNode* las = m_assignp;
 	    m_assignp = nodep;
@@ -195,7 +195,7 @@ private:
 	    m_assignp = las;
 	}
    }
-    virtual void visit(AstVarRef* nodep, AstNUser*) {
+    virtual void visit(AstVarRef* nodep) {
 	AstVar* varp=nodep->varp();
 	if (m_check == CT_SEQ
 	    && m_assignp
@@ -214,7 +214,7 @@ private:
 	}
    }
    //--------------------
-    virtual void visit(AstNode* nodep, AstNUser*) {
+    virtual void visit(AstNode* nodep) {
 	nodep->iterateChildren(*this);
    }
 public:
@@ -244,7 +244,7 @@ private:
    bool	m_itemSequent;	// Found a SenItem sequential

    // VISITORS
-    virtual void visit(AstScope* nodep, AstNUser*) {
+    virtual void visit(AstScope* nodep) {
 	// Create required actives and add to scope
 	UINFO(4," SCOPE   "<<nodep<<endl);
 	// Clear last scope's names, and collect this scope's existing names
@@ -252,10 +252,10 @@ private:
 	m_scopeFinalp = NULL;
 	nodep->iterateChildren(*this);
    }
-    virtual void visit(AstActive* nodep, AstNUser*) {
+    virtual void visit(AstActive* nodep) {
 	// Actives are being formed, so we can ignore any already made
    }
-    virtual void visit(AstInitial* nodep, AstNUser*) {
+    virtual void visit(AstInitial* nodep) {
 	// Relink to IACTIVE, unless already under it
 	UINFO(4,"    INITIAL "<<nodep<<endl);
 	ActiveDlyVisitor dlyvisitor (nodep, ActiveDlyVisitor::CT_INITIAL);
@@ -263,28 +263,28 @@ private:
 	nodep->unlinkFrBack();
 	wantactivep->addStmtsp(nodep);
    }
-    virtual void visit(AstAssignAlias* nodep, AstNUser*) {
+    virtual void visit(AstAssignAlias* nodep) {
 	// Relink to CACTIVE, unless already under it
 	UINFO(4,"    ASSIGNW "<<nodep<<endl);
 	AstActive* wantactivep = m_namer.getCActive(nodep->fileline());
 	nodep->unlinkFrBack();
 	wantactivep->addStmtsp(nodep);
    }
-    virtual void visit(AstAssignW* nodep, AstNUser*) {
+    virtual void visit(AstAssignW* nodep) {
 	// Relink to CACTIVE, unless already under it
 	UINFO(4,"    ASSIGNW "<<nodep<<endl);
 	AstActive* wantactivep = m_namer.getCActive(nodep->fileline());
 	nodep->unlinkFrBack();
 	wantactivep->addStmtsp(nodep);
    }
-    virtual void visit(AstCoverToggle* nodep, AstNUser*) {
+    virtual void visit(AstCoverToggle* nodep) {
 	// Relink to CACTIVE, unless already under it
 	UINFO(4,"    COVERTOGGLE "<<nodep<<endl);
 	AstActive* wantactivep = m_namer.getCActive(nodep->fileline());
 	nodep->unlinkFrBack();
 	wantactivep->addStmtsp(nodep);
    }
-    virtual void visit(AstFinal* nodep, AstNUser*) {
+    virtual void visit(AstFinal* nodep) {
 	// Relink to CFUNC for the final
 	UINFO(4,"    FINAL "<<nodep<<endl);
 	if (!nodep->bodysp()) { // Empty, Kill it.
@@ -323,13 +323,15 @@ private:
 	// Read sensitivitues
 	m_itemCombo = false;
 	m_itemSequent = false;
-	oldsensesp->iterateAndNext(*this);
+	if (oldsensesp) oldsensesp->iterateAndNext(*this);
 	bool combo = m_itemCombo;
 	bool sequent = m_itemSequent;

 	if (!combo && !sequent) combo=true;	// If no list, Verilog 2000: always @ (*)
 	if (combo && sequent) {
-	    nodep->v3error("Unsupported: Mixed edge (pos/negedge) and activity (no edge) sensitive activity list");
+	    if (!v3Global.opt.bboxUnsup()) {
+		nodep->v3error("Unsupported: Mixed edge (pos/negedge) and activity (no edge) sensitive activity list");
+	    }
 	    sequent = false;
 	}

@@ -370,7 +372,7 @@ private:
 	    ActiveDlyVisitor dlyvisitor (nodep, ActiveDlyVisitor::CT_SEQ);
 	}
    }
-    virtual void visit(AstAlways* nodep, AstNUser*) {
+    virtual void visit(AstAlways* nodep) {
 	// Move always to appropriate ACTIVE based on its sense list
 	UINFO(4,"    ALW   "<<nodep<<endl);
 	//if (debug()>=9) nodep->dumpTree(cout,"  Alw: ");
@@ -382,13 +384,13 @@ private:
 	}
 	visitAlways(nodep, nodep->sensesp(), nodep->keyword());
    }
-    virtual void visit(AstAlwaysPublic* nodep, AstNUser*) {
+    virtual void visit(AstAlwaysPublic* nodep) {
 	// Move always to appropriate ACTIVE based on its sense list
 	UINFO(4,"    ALWPub   "<<nodep<<endl);
 	//if (debug()>=9) nodep->dumpTree(cout,"  Alw: ");
 	visitAlways(nodep, nodep->sensesp(), VAlwaysKwd::ALWAYS);
    }
-    virtual void visit(AstSenGate* nodep, AstNUser*) {
+    virtual void visit(AstSenGate* nodep) {
 	AstSenItem* subitemp = nodep->sensesp();
 	if (subitemp->edgeType() != AstEdgeType::ET_ANYEDGE
 	    && subitemp->edgeType() != AstEdgeType::ET_POSEDGE
@@ -397,7 +399,7 @@ private:
 	}
 	nodep->iterateChildren(*this);
    }
-    virtual void visit(AstSenItem* nodep, AstNUser*) {
+    virtual void visit(AstSenItem* nodep) {
 	if (nodep->edgeType() == AstEdgeType::ET_ANYEDGE) {
 	    m_itemCombo = true;
 	    // Delete the sensitivity
@@ -413,10 +415,10 @@ private:
    }

    // Empty visitors, speed things up
-    virtual void visit(AstNodeMath* nodep, AstNUser*) {}
-    virtual void visit(AstVarScope* nodep, AstNUser*) {}
+    virtual void visit(AstNodeMath* nodep) {}
+    virtual void visit(AstVarScope* nodep) {}
    //--------------------
-    virtual void visit(AstNode* nodep, AstNUser*) {
+    virtual void visit(AstNode* nodep) {
 	nodep->iterateChildren(*this);
    }
 public:
@@ -436,5 +438,5 @@ public:
 void V3Active::activeAll(AstNetlist* nodep) {
    UINFO(2,__FUNCTION__<<": "<<endl);
    ActiveVisitor visitor (nodep);
-    V3Global::dumpCheckGlobalTree("active.tree", 0, v3Global.opt.dumpTreeLevel(__FILE__) >= 3);
+    V3Global::dumpCheckGlobalTree("active", 0, v3Global.opt.dumpTreeLevel(__FILE__) >= 3);
 }
@@ -6,7 +6,7 @@
 //
 //*************************************************************************
 //
-// Copyright 2003-2015 by Wilson Snyder.  This program is free software; you can
+// Copyright 2003-2017 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.
@@ -6,7 +6,7 @@
 //
 //*************************************************************************
 //
-// Copyright 2003-2015 by Wilson Snyder.  This program is free software; you can
+// Copyright 2003-2017 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.
@@ -65,19 +65,19 @@ private:
    }

    // VISITORS
-    virtual void visit(AstTopScope* nodep, AstNUser*) {
+    virtual void visit(AstTopScope* nodep) {
 	m_topscopep = nodep;
 	m_finder.main(m_topscopep);
 	nodep->iterateChildren(*this);
 	m_topscopep = NULL;
    }
-    virtual void visit(AstNodeModule* nodep, AstNUser*) {
+    virtual void visit(AstNodeModule* nodep) {
 	// Create required actives and add to module
 	// We can start ordering at a module, or a scope
 	UINFO(4," MOD   "<<nodep<<endl);
 	nodep->iterateChildren(*this);
    }
-    virtual void visit(AstActive* nodep, AstNUser*) {
+    virtual void visit(AstActive* nodep) {
 	UINFO(4,"   ACTIVE "<<nodep<<endl);
 	V3Const::constifyExpensiveEdit(nodep); // Remove duplicate clocks and such; sensesp() may change!
 	AstSenTree* sensesp = nodep->sensesp();
@@ -108,7 +108,7 @@ private:
 	    // Move the active's contents to the other active
 	    UINFO(4,"   merge active "<<sensesp<<" into "<<wantp<<endl);
 	    if (nodep->sensesStorep()) {
-		if (sensesp != nodep->sensesStorep()) nodep->v3fatalSrc("sensesStore should have been deleted earlier if different\n");
+		if (sensesp != nodep->sensesStorep()) nodep->v3fatalSrc("sensesStore should have been deleted earlier if different");
 		sensesp->unlinkFrBack();
 		// There may be other references to same sense tree,
 		// we'll be removing all references when we get to them,
@@ -120,29 +120,29 @@ private:
 	// No need to do statements under it, they're already moved.
 	//nodep->iterateChildren(*this);
    }
-    virtual void visit(AstInitial* nodep, AstNUser*) {
+    virtual void visit(AstInitial* nodep) {
 	nodep->v3fatalSrc("Node should have been under ACTIVE");
    }
-    virtual void visit(AstAssignAlias* nodep, AstNUser*) {
+    virtual void visit(AstAssignAlias* nodep) {
 	nodep->v3fatalSrc("Node should have been under ACTIVE");
    }
-    virtual void visit(AstAssignW* nodep, AstNUser*) {
+    virtual void visit(AstAssignW* nodep) {
 	nodep->v3fatalSrc("Node should have been under ACTIVE");
    }
-    virtual void visit(AstAlways* nodep, AstNUser*) {
+    virtual void visit(AstAlways* nodep) {
 	nodep->v3fatalSrc("Node should have been under ACTIVE");
    }
-    virtual void visit(AstAlwaysPublic* nodep, AstNUser*) {
+    virtual void visit(AstAlwaysPublic* nodep) {
 	nodep->v3fatalSrc("Node should have been under ACTIVE");
    }
-    virtual void visit(AstFinal* nodep, AstNUser*) {
+    virtual void visit(AstFinal* nodep) {
 	nodep->v3fatalSrc("Node should have been deleted");
    }
    // Empty visitors, speed things up
-    virtual void visit(AstNodeMath* nodep, AstNUser*) {}
-    virtual void visit(AstVarScope* nodep, AstNUser*) {}
+    virtual void visit(AstNodeMath* nodep) {}
+    virtual void visit(AstVarScope* nodep) {}
    //--------------------
-    virtual void visit(AstNode* nodep, AstNUser*) {
+    virtual void visit(AstNode* nodep) {
 	nodep->iterateChildren(*this);
    }
 public:
@@ -160,5 +160,5 @@ public:
 void V3ActiveTop::activeTopAll(AstNetlist* nodep) {
    UINFO(2,__FUNCTION__<<": "<<endl);
    ActiveTopVisitor visitor (nodep);
-    V3Global::dumpCheckGlobalTree("activetop.tree", 0, v3Global.opt.dumpTreeLevel(__FILE__) >= 3);
+    V3Global::dumpCheckGlobalTree("activetop", 0, v3Global.opt.dumpTreeLevel(__FILE__) >= 3);
 }
@@ -6,7 +6,7 @@
 //
 //*************************************************************************
 //
-// Copyright 2003-2015 by Wilson Snyder.  This program is free software; you can
+// Copyright 2003-2017 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.
@@ -6,7 +6,7 @@
 //
 //*************************************************************************
 //
-// Copyright 2005-2015 by Wilson Snyder.  This program is free software; you can
+// Copyright 2005-2017 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.
@@ -67,7 +67,7 @@ private:
 	    timesp->unlinkFrBackWithNext();
 	    timenewp->addNext(timesp);
 	}
-	nodep->fmtp()->exprsp(timenewp);
+	nodep->fmtp()->addExprsp(timenewp);
 	if (!nodep->fmtp()->scopeNamep() && nodep->fmtp()->formatScopeTracking()) {
 	    nodep->fmtp()->scopeNamep(new AstScopeName(nodep->fileline()));
 	}
@@ -119,7 +119,7 @@ private:
 	} else {
 	    nodep->v3fatalSrc("Unknown node type");
 	}
-	if (stmtsp) bodysp = bodysp->addNext(stmtsp);
+	if (bodysp && stmtsp) bodysp = bodysp->addNext(stmtsp);
 	AstIf* ifp = new AstIf (nodep->fileline(), propp, bodysp, NULL);
 	bodysp = ifp;
 	if (nodep->castVAssert()) ifp->branchPred(AstBranchPred::BP_UNLIKELY);
@@ -162,8 +162,8 @@ private:
 	// Bye
 	pushDeletep(nodep); VL_DANGLING(nodep);
    }
-    
-    virtual void visit(AstIf* nodep, AstNUser*) {
+
+    virtual void visit(AstIf* nodep) {
 	if (nodep->user1SetOnce()) return;
 	if (nodep->uniquePragma() || nodep->unique0Pragma()) {
 	    AstNodeIf* ifp = nodep;
@@ -177,12 +177,12 @@ private:

 		// Recurse into the true case.
 		ifp->ifsp()->iterateAndNext(*this);
-		
+
 		// If the last else is not an else if, recurse into that too.
 		if (ifp->elsesp() && !nextifp) {
 		    ifp->elsesp()->iterateAndNext(*this);
 		}
-		
+
 		// Build a bitmask of the true predicates
 	        AstNode* predp = ifp->condp()->cloneTree(false);
 	        if (propp) {
@@ -195,18 +195,21 @@ private:
 		if (ifp->elsesp() && !nextifp) {
 		    hasDefaultElse = true;
 		}
-		
+
 		ifp = nextifp;
 	    } while (ifp);

 	    AstNode *newifp = nodep->cloneTree(false);
 	    bool allow_none = nodep->unique0Pragma();
-	    
+
+	    // Empty case means no property
+	    if (!propp) propp = new AstConst(nodep->fileline(), AstConst::LogicFalse());
+
 	    // Note: if this ends with an 'else', then we don't need to validate that one of the
 	    // predicates evaluates to true.
 	    AstNode* ohot = ((allow_none || hasDefaultElse)
-			     ? (new AstOneHot0(nodep->fileline(), propp))->castNode()
-			     : (new AstOneHot (nodep->fileline(), propp))->castNode());
+			     ? static_cast<AstNode*>(new AstOneHot0(nodep->fileline(), propp))
+			     : static_cast<AstNode*>(new AstOneHot (nodep->fileline(), propp)));
 	    AstIf* checkifp = new AstIf (nodep->fileline(),
 					 new AstLogNot (nodep->fileline(), ohot),
 					 newFireAssert(nodep, "'unique if' statement violated"),
@@ -220,7 +223,7 @@ private:
    }

    // VISITORS  //========== Case assertions
-    virtual void visit(AstCase* nodep, AstNUser*) {
+    virtual void visit(AstCase* nodep) {
 	nodep->iterateChildren(*this);
 	if (!nodep->user1SetOnce()) {
 	    bool has_default=false;
@@ -245,17 +248,27 @@ private:
 		    AstNode* propp = NULL;
 		    for (AstCaseItem* itemp = nodep->itemsp(); itemp; itemp=itemp->nextp()->castCaseItem()) {
 			for (AstNode* icondp = itemp->condsp(); icondp!=NULL; icondp=icondp->nextp()) {
-			    AstNode* onep = new AstEq(icondp->fileline(),
-						      nodep->exprp()->cloneTree(false),
-						      icondp->cloneTree(false));
+			    AstNode* onep;
+			    if (nodep->casex() || nodep->casez() || nodep->caseInside()) {
+				onep = AstEqWild::newTyped(itemp->fileline(),
+							   nodep->exprp()->cloneTree(false),
+							   icondp->cloneTree(false));
+			    } else {
+				onep = AstEq::newTyped(icondp->fileline(),
+						       nodep->exprp()->cloneTree(false),
+						       icondp->cloneTree(false));
+			    }
 			    if (propp) propp = new AstConcat(icondp->fileline(), onep, propp);
 			    else propp = onep;
 			}
 		    }
+		    // Empty case means no property
+		    if (!propp) propp = new AstConst(nodep->fileline(), AstConst::LogicFalse());
+
 		    bool allow_none = has_default || nodep->unique0Pragma();
 		    AstNode* ohot = (allow_none
-				     ? (new AstOneHot0(nodep->fileline(), propp))->castNode()
-				     : (new AstOneHot (nodep->fileline(), propp))->castNode());
+				     ? static_cast<AstNode*>(new AstOneHot0(nodep->fileline(), propp))
+				     : static_cast<AstNode*>(new AstOneHot (nodep->fileline(), propp)));
 		    AstIf* ifp = new AstIf (nodep->fileline(),
 					    new AstLogNot (nodep->fileline(), ohot),
 					    newFireAssert(nodep, "synthesis parallel_case, but multiple matches found"),
@@ -268,7 +281,7 @@ private:
    }

    // VISITORS  //========== Statements
-    virtual void visit(AstDisplay* nodep, AstNUser*) {
+    virtual void visit(AstDisplay* nodep) {
 	nodep->iterateChildren(*this);
 	// Replace the special types with standard text
 	if (nodep->displayType()==AstDisplayType::DT_INFO) {
@@ -281,27 +294,27 @@ private:
 	}
    }

-    virtual void visit(AstPslCover* nodep, AstNUser*) {
+    virtual void visit(AstPslCover* nodep) {
 	nodep->iterateChildren(*this);
 	if (m_beginp && nodep->name() == "") nodep->name(m_beginp->name());
 	newPslAssertion(nodep, nodep->propp(), nodep->sentreep(),
 			nodep->stmtsp(), nodep->name()); VL_DANGLING(nodep);
 	++m_statAsCover;
    }
-    virtual void visit(AstVAssert* nodep, AstNUser*) {
+    virtual void visit(AstVAssert* nodep) {
 	nodep->iterateChildren(*this);
 	newVAssertion(nodep, nodep->propp()); VL_DANGLING(nodep);
 	++m_statAsSV;
    }

-    virtual void visit(AstNodeModule* nodep, AstNUser*) {
+    virtual void visit(AstNodeModule* nodep) {
 	m_modp = nodep;
 	//
 	nodep->iterateChildren(*this);
 	// Reset defaults
 	m_modp = NULL;
    }
-    virtual void visit(AstBegin* nodep, AstNUser*) {
+    virtual void visit(AstBegin* nodep) {
 	// This code is needed rather than a visitor in V3Begin,
 	// because V3Assert is called before V3Begin
 	AstBegin* lastp = m_beginp;
@@ -312,7 +325,7 @@ private:
 	m_beginp = lastp;
    }

-    virtual void visit(AstNode* nodep, AstNUser*) {
+    virtual void visit(AstNode* nodep) {
 	nodep->iterateChildren(*this);
    }
 public:
@@ -337,5 +350,5 @@ public:
 void V3Assert::assertAll(AstNetlist* nodep) {
    UINFO(2,__FUNCTION__<<": "<<endl);
    AssertVisitor visitor (nodep);
-    V3Global::dumpCheckGlobalTree("assert.tree", 0, v3Global.opt.dumpTreeLevel(__FILE__) >= 3);
+    V3Global::dumpCheckGlobalTree("assert", 0, v3Global.opt.dumpTreeLevel(__FILE__) >= 3);
 }
@@ -6,7 +6,7 @@
 //
 //*************************************************************************
 //
-// Copyright 2005-2015 by Wilson Snyder.  This program is free software; you can
+// Copyright 2005-2017 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.
@@ -6,7 +6,7 @@
 //
 //*************************************************************************
 //
-// Copyright 2005-2015 by Wilson Snyder.  This program is free software; you can
+// Copyright 2005-2017 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.
@@ -73,7 +73,7 @@ private:
    }

    // VISITORS  //========== Statements
-    virtual void visit(AstClocking* nodep, AstNUser*) {
+    virtual void visit(AstClocking* nodep) {
 	UINFO(8,"   CLOCKING"<<nodep<<endl);
 	// Store the new default clock, reset on new module
 	m_seniDefaultp = nodep->sensesp();
@@ -86,14 +86,14 @@ private:
 	pushDeletep(nodep); VL_DANGLING(nodep);
    }

-    virtual void visit(AstPslCover* nodep, AstNUser*) {
+    virtual void visit(AstPslCover* nodep) {
 	if (nodep->sentreep()) return;  // Already processed
 	clearAssertInfo();
 	nodep->iterateChildren(*this);
 	nodep->sentreep(newSenTree(nodep));
 	clearAssertInfo();
    }
-    virtual void visit(AstPslClocked* nodep, AstNUser*) {
+    virtual void visit(AstPslClocked* nodep) {
 	nodep->iterateChildren(*this);
 	if (m_senip) {
 	    nodep->v3error("Unsupported: Only one PSL clock allowed per assertion");
@@ -111,12 +111,12 @@ private:
 	nodep->replaceWith(blockp);
 	pushDeletep(nodep); VL_DANGLING(nodep);
    }
-    virtual void visit(AstNodeModule* nodep, AstNUser*) {
+    virtual void visit(AstNodeModule* nodep) {
 	nodep->iterateChildren(*this);
 	// Reset defaults
 	m_seniDefaultp = NULL;
    }
-    virtual void visit(AstNode* nodep, AstNUser*) {
+    virtual void visit(AstNode* nodep) {
 	nodep->iterateChildren(*this);
    }

@@ -137,5 +137,5 @@ public:
 void V3AssertPre::assertPreAll(AstNetlist* nodep) {
    UINFO(2,__FUNCTION__<<": "<<endl);
    AssertPreVisitor visitor (nodep);
-    V3Global::dumpCheckGlobalTree("assertpre.tree", 0, v3Global.opt.dumpTreeLevel(__FILE__) >= 3);
+    V3Global::dumpCheckGlobalTree("assertpre", 0, v3Global.opt.dumpTreeLevel(__FILE__) >= 3);
 }
@@ -6,7 +6,7 @@
 //
 //*************************************************************************
 //
-// Copyright 2005-2015 by Wilson Snyder.  This program is free software; you can
+// Copyright 2005-2017 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.
@@ -6,7 +6,7 @@
 //
 //*************************************************************************
 //
-// Copyright 2003-2015 by Wilson Snyder.  This program is free software; you can
+// Copyright 2003-2017 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.
@@ -80,30 +80,30 @@ void AstNode::init() {
    // Attributes
    m_didWidth = false;
    m_doingWidth = false;
-    m_user1p = NULL;
+    m_user1u = VNUser(0);
    m_user1Cnt = 0;
-    m_user2p = NULL;
+    m_user2u = VNUser(0);
    m_user2Cnt = 0;
-    m_user3p = NULL;
+    m_user3u = VNUser(0);
    m_user3Cnt = 0;
-    m_user4p = NULL;
+    m_user4u = VNUser(0);
    m_user4Cnt = 0;
-    m_user5p = NULL;
+    m_user5u = VNUser(0);
    m_user5Cnt = 0;
 }

 string AstNode::encodeName(const string& namein) {
    // Encode signal name raw from parser, then not called again on same signal
-    const char* start = namein.c_str();
    string out;
-    for (const char* pos = start; *pos; pos++) {
-	if ((pos==start) ? isalpha(pos[0])  // digits can't lead identifiers
+    for (string::const_iterator pos = namein.begin(); pos!=namein.end(); ++pos) {
+	if ((pos==namein.begin()) ? isalpha(pos[0])  // digits can't lead identifiers
 	    : isalnum(pos[0])) {
 	    out += pos[0];
 	} else if (pos[0]=='_') {
 	    if (pos[1]=='_') {
 		out += "_"; out += "__05F";  // hex(_) = 0x5F
-		pos++;
+		++pos;
+		if (pos==namein.end()) break;
 	    } else {
 		out += pos[0];
 	    }
@@ -166,44 +166,53 @@ string AstNode::vcdName(const string& namein) {
 }

 string AstNode::prettyName(const string& namein) {
+    // This function is somewhat hot, so we short-circuit some compares
    string pretty;
    pretty = "";
+    pretty.reserve(namein.length());
    for (const char* pos = namein.c_str(); *pos; ) {
-	if (0==strncmp(pos,"__BRA__",7)) {
-	    pretty += "[";
-	    pos += 7;
-	}
-	else if (0==strncmp(pos,"__KET__",7)) {
-	    pretty += "]";
-	    pos += 7;
-	}
-	else if (0==strncmp(pos,"__DOT__",7)) {
-	    pretty += ".";
-	    pos += 7;
-	}
-	else if (0==strncmp(pos,"->",2)) {
+	if (pos[0]=='-' && pos[1]=='>') { // ->
 	    pretty += ".";
 	    pos += 2;
+	    continue;
 	}
-	else if (0==strncmp(pos,"__PVT__",7)) {
-	    pretty += "";
-	    pos += 7;
-	}
-	else if (pos[0]=='_' && pos[1]=='_' && pos[2]=='0'
-		 && isxdigit(pos[3]) && isxdigit(pos[4])) {
-	    char value = 0;
-	    value += 16*(isdigit(pos[3]) ? (pos[3]-'0') : (tolower(pos[3])-'a'+10));
-	    value +=    (isdigit(pos[4]) ? (pos[4]-'0') : (tolower(pos[4])-'a'+10));
-	    pretty += value;
-	    pos += 5;
-	}
-	else {
-	    pretty += pos[0];
-	    pos++;
+	if (pos[0]=='_' && pos[1]=='_') { // Short-circuit
+	    if (0==strncmp(pos,"__BRA__",7)) {
+		pretty += "[";
+		pos += 7;
+		continue;
+	    }
+	    if (0==strncmp(pos,"__KET__",7)) {
+		pretty += "]";
+		pos += 7;
+		continue;
+	    }
+	    if (0==strncmp(pos,"__DOT__",7)) {
+		pretty += ".";
+		pos += 7;
+		continue;
+	    }
+	    if (0==strncmp(pos,"__PVT__",7)) {
+		pretty += "";
+		pos += 7;
+		continue;
+	    }
+	    if (pos[0]=='_' && pos[1]=='_' && pos[2]=='0'
+		     && isxdigit(pos[3]) && isxdigit(pos[4])) {
+		char value = 0;
+		value += 16*(isdigit(pos[3]) ? (pos[3]-'0') : (tolower(pos[3])-'a'+10));
+		value +=    (isdigit(pos[4]) ? (pos[4]-'0') : (tolower(pos[4])-'a'+10));
+		pretty += value;
+		pos += 5;
+		continue;
+	    }
 	}
+	// Default
+	pretty += pos[0];
+	++pos;
    }
-    if (pretty.substr(0,4) == "TOP.") pretty.replace(0,4,"");
-    if (pretty.substr(0,5) == "TOP->") pretty.replace(0,5,"");
+    if (pretty[0]=='T' && pretty.substr(0,4) == "TOP.") pretty.replace(0,4,"");
+    if (pretty[0]=='T' && pretty.substr(0,5) == "TOP->") pretty.replace(0,5,"");
    return pretty;
 }

@@ -235,20 +244,20 @@ inline void AstNode::debugTreeChange(const char* prefix, int lineno, bool next)
 #endif
 }

-AstNode* AstNode::addNext(AstNode* newp) {
+AstNode* AstNode::addNext(AstNode* nodep, AstNode* newp) {
    // Add to m_nextp, returns this
-    UASSERT(newp,"Null item passed to addNext\n");
-    this->debugTreeChange("-addNextThs: ", __LINE__, false);
+    UDEBUGONLY(if (!newp) nodep->v3fatalSrc("Null item passed to addNext"););
+    nodep->debugTreeChange("-addNextThs: ", __LINE__, false);
    newp->debugTreeChange("-addNextNew: ", __LINE__, true);
-    if (this == NULL) {
+    if (!nodep) {  // verilog.y and lots of other places assume this
 	return (newp);
    } else {
 	// Find end of old list
-	AstNode* oldtailp = this;
+	AstNode* oldtailp = nodep;
 	if (oldtailp->m_nextp) {
 	    if (oldtailp->m_headtailp) {
 		oldtailp = oldtailp->m_headtailp;  // This=beginning of list, jump to end
-		UASSERT(!oldtailp->m_nextp, "Node had next, but headtail says it shouldn't");
+		UDEBUGONLY(if (oldtailp->m_nextp) nodep->v3fatalSrc("Node had next, but headtail says it shouldn't"););
 	    } else {
 		// Though inefficent, we are occasionally passed a addNext in the middle of a list.
 		while (oldtailp->m_nextp != NULL) oldtailp = oldtailp->m_nextp;
@@ -267,21 +276,21 @@ AstNode* AstNode::addNext(AstNode* newp) {
 	newp->editCountInc();
 	if (oldtailp->m_iterpp) *(oldtailp->m_iterpp) = newp;	// Iterate on new item
    }
-    this->debugTreeChange("-addNextOut:", __LINE__, true);
-    return this;
+    nodep->debugTreeChange("-addNextOut:", __LINE__, true);
+    return nodep;
 }

-AstNode* AstNode::addNextNull(AstNode* newp) {
-    if (!newp) return this;
-    return addNext(newp);
+AstNode* AstNode::addNextNull(AstNode* nodep, AstNode* newp) {
+    if (!newp) return nodep;
+    return addNext(nodep, newp);
 }

 void AstNode::addNextHere(AstNode* newp) {
    // Add to m_nextp on exact node passed, not at the end.
    //  This could be at head, tail, or both (single)
    //  New  could be head of single node, or list
+    UDEBUGONLY(UASSERT(dynamic_cast<AstNode*>(this),"this should not be NULL"););
    UASSERT(newp,"Null item passed to addNext");
-    UASSERT(this,"Null base node");
    UASSERT(newp->backp()==NULL,"New node (back) already assigned?");
    this->debugTreeChange("-addHereThs: ", __LINE__, false);
    newp->debugTreeChange("-addHereNew: ", __LINE__, true);
@@ -605,12 +614,12 @@ void AstNode::swapWith (AstNode* bp) {
 // Clone

 AstNode* AstNode::cloneTreeIter() {
-    if (!this) return NULL;
+    // private: Clone single node and children
    AstNode* newp = this->clone();
-    newp->op1p(this->m_op1p->cloneTreeIterList());
-    newp->op2p(this->m_op2p->cloneTreeIterList());
-    newp->op3p(this->m_op3p->cloneTreeIterList());
-    newp->op4p(this->m_op4p->cloneTreeIterList());
+    if (this->m_op1p) newp->op1p(this->m_op1p->cloneTreeIterList());
+    if (this->m_op2p) newp->op2p(this->m_op2p->cloneTreeIterList());
+    if (this->m_op3p) newp->op3p(this->m_op3p->cloneTreeIterList());
+    if (this->m_op4p) newp->op4p(this->m_op4p->cloneTreeIterList());
    newp->m_iterpp = NULL;
    newp->clonep(this);		// Save pointers to/from both to simplify relinking.
    this->clonep(newp);		// Save pointers to/from both to simplify relinking.
@@ -618,10 +627,10 @@ AstNode* AstNode::cloneTreeIter() {
 }

 AstNode* AstNode::cloneTreeIterList() {
-    // Clone list of nodes, set m_headtailp
-    if (!this) return NULL;
+    // private: Clone list of nodes, set m_headtailp
    AstNode* newheadp = NULL;
    AstNode* newtailp = NULL;
+    // Audited to make sure this is never NULL
    for (AstNode* oldp = this; oldp; oldp=oldp->m_nextp) {
 	AstNode* newp = oldp->cloneTreeIter();
 	newp->m_headtailp = NULL;
@@ -636,7 +645,7 @@ AstNode* AstNode::cloneTreeIterList() {
 }

 AstNode* AstNode::cloneTree(bool cloneNextLink) {
-    if (!this) return NULL;
+    if (!this) return NULL;  // verilog.y relies on this
    this->debugTreeChange("-cloneThs: ", __LINE__, cloneNextLink);
    cloneClearTree();
    AstNode* newp;
@@ -657,7 +666,7 @@ AstNode* AstNode::cloneTree(bool cloneNextLink) {
 // Delete

 void AstNode::deleteNode() {
-    if (!this) return;
+    // private: Delete single node. Publicly call deleteTree() instead.
    UASSERT(m_backp==NULL,"Delete called on node with backlink still set\n");
    editCountInc();
    // Change links of old node so we coredump if used
@@ -677,14 +686,15 @@ AstNode::~AstNode() {
 }

 void AstNode::deleteTreeIter() {
-    if (!this) return;
+    // private: Delete list of nodes. Publicly call deleteTree() instead.
+    // Audited to make sure this is never NULL
    for (AstNode* nodep=this, *nnextp; nodep; nodep=nnextp) {
 	nnextp = nodep->m_nextp;
 	// MUST be depth first!
-	nodep->m_op1p->deleteTreeIter();
-	nodep->m_op2p->deleteTreeIter();
-	nodep->m_op3p->deleteTreeIter();
-	nodep->m_op4p->deleteTreeIter();
+	if (nodep->m_op1p) nodep->m_op1p->deleteTreeIter();
+	if (nodep->m_op2p) nodep->m_op2p->deleteTreeIter();
+	if (nodep->m_op3p) nodep->m_op3p->deleteTreeIter();
+	if (nodep->m_op4p) nodep->m_op4p->deleteTreeIter();
 	nodep->m_nextp = NULL;
 	nodep->m_backp = NULL;
 	nodep->deleteNode();
@@ -694,7 +704,6 @@ void AstNode::deleteTreeIter() {
 void AstNode::deleteTree() {
    // deleteTree always deletes the next link, because you must have called
    // unlinkFromBack or unlinkFromBackWithNext as appropriate before calling this.
-    if (!this) return;
    UASSERT(m_backp==NULL,"Delete called on node with backlink still set\n");
    this->debugTreeChange("-delTree:  ", __LINE__, true);
    this->editCountInc();
@@ -707,6 +716,7 @@ void AstNode::deleteTree() {

 #ifdef VL_LEAK_CHECKS
 void* AstNode::operator new(size_t size) {
+    // Optimization note: Aligning to cache line is a loss, due to lost packing
    AstNode* objp = static_cast<AstNode*>(::operator new(size));
    V3Broken::addNewed(objp);
    return objp;
@@ -723,53 +733,51 @@ void AstNode::operator delete(void* objp, size_t size) {
 //======================================================================
 // Iterators

-void AstNode::iterateChildren(AstNVisitor& v, AstNUser* vup) {
+void AstNode::iterateChildren(AstNVisitor& v) {
    // This is a very hot function
-    if (!this) return;
+    // Optimization note: Grabbing m_op#p->m_nextp is a net loss
    ASTNODE_PREFETCH(m_op1p);
    ASTNODE_PREFETCH(m_op2p);
    ASTNODE_PREFETCH(m_op3p);
    ASTNODE_PREFETCH(m_op4p);
-    // if () not needed since iterateAndNext accepts null this, but faster with it.
-    if (m_op1p) m_op1p->iterateAndNext(v, vup);
-    if (m_op2p) m_op2p->iterateAndNext(v, vup);
-    if (m_op3p) m_op3p->iterateAndNext(v, vup);
-    if (m_op4p) m_op4p->iterateAndNext(v, vup);
+    if (m_op1p) m_op1p->iterateAndNext(v);
+    if (m_op2p) m_op2p->iterateAndNext(v);
+    if (m_op3p) m_op3p->iterateAndNext(v);
+    if (m_op4p) m_op4p->iterateAndNext(v);
 }

-void AstNode::iterateChildrenConst(AstNVisitor& v, AstNUser* vup) {
+void AstNode::iterateChildrenConst(AstNVisitor& v) {
    // This is a very hot function
-    if (!this) return;
    ASTNODE_PREFETCH(m_op1p);
    ASTNODE_PREFETCH(m_op2p);
    ASTNODE_PREFETCH(m_op3p);
    ASTNODE_PREFETCH(m_op4p);
-    // if () not needed since iterateAndNext accepts null this, but faster with it.
-    if (m_op1p) m_op1p->iterateAndNextConst(v, vup);
-    if (m_op2p) m_op2p->iterateAndNextConst(v, vup);
-    if (m_op3p) m_op3p->iterateAndNextConst(v, vup);
-    if (m_op4p) m_op4p->iterateAndNextConst(v, vup);
+    if (m_op1p) m_op1p->iterateAndNextConst(v);
+    if (m_op2p) m_op2p->iterateAndNextConst(v);
+    if (m_op3p) m_op3p->iterateAndNextConst(v);
+    if (m_op4p) m_op4p->iterateAndNextConst(v);
 }

-void AstNode::iterateAndNext(AstNVisitor& v, AstNUser* vup) {
+void AstNode::iterateAndNext(AstNVisitor& v) {
    // This is a very hot function
    // IMPORTANT: If you replace a node that's the target of this iterator,
    // then the NEW node will be iterated on next, it isn't skipped!
-    // if (!this) return;  // Part of for()
    // Future versions of this function may require the node to have a back to be iterated;
    // there's no lower level reason yet though the back must exist.
    AstNode* nodep=this;
 #ifdef VL_DEBUG  // Otherwise too hot of a function for debug
    if (VL_UNLIKELY(nodep && !nodep->m_backp)) nodep->v3fatalSrc("iterateAndNext node has no back");
 #endif
-    while (nodep) {
+    if (nodep) ASTNODE_PREFETCH(nodep->m_nextp);
+    while (nodep) {   // effectively: if (!this) return;  // Callers rely on this
+	if (nodep->m_nextp) ASTNODE_PREFETCH(nodep->m_nextp->m_nextp);
 	AstNode* niterp = nodep;  // This address may get stomped via m_iterpp if the node is edited
-	ASTNODE_PREFETCH(nodep->m_nextp);
 	// Desirable check, but many places where multiple iterations are OK
 	//if (VL_UNLIKELY(niterp->m_iterpp)) niterp->v3fatalSrc("IterateAndNext under iterateAndNext may miss edits");
+	// Optimization note: Doing PREFETCH_RW on m_iterpp is a net even
 	// cppcheck-suppress nullPointer
 	niterp->m_iterpp = &niterp;
-	niterp->accept(v, vup);
+	niterp->accept(v);
 	// accept may do a replaceNode and change niterp on us...
 	//if (niterp != nodep) UINFO(1,"iterateAndNext edited "<<(void*)nodep<<" now into "<<(void*)niterp<<endl);  // niterp maybe NULL, so need cast
 	if (!niterp) return;  // Perhaps node deleted inside accept
@@ -782,38 +790,37 @@ void AstNode::iterateAndNext(AstNVisitor& v, AstNUser* vup) {
    }
 }

-void AstNode::iterateListBackwards(AstNVisitor& v, AstNUser* vup) {
-    if (!this) return;
+void AstNode::iterateListBackwards(AstNVisitor& v) {
+    UDEBUGONLY(UASSERT(dynamic_cast<AstNode*>(this),"this should not be NULL"););
    AstNode* nodep=this;
    while (nodep->m_nextp) nodep=nodep->m_nextp;
    while (nodep) {
 	// Edits not supported: nodep->m_iterpp = &nodep;
-	nodep->accept(v, vup);
+	nodep->accept(v);
 	if (nodep->backp()->m_nextp == nodep) nodep=nodep->backp();
 	else nodep = NULL;  // else: backp points up the tree.
    }
 }

-void AstNode::iterateChildrenBackwards(AstNVisitor& v, AstNUser* vup) {
-    if (!this) return;
-    this->op1p()->iterateListBackwards(v,vup);
-    this->op2p()->iterateListBackwards(v,vup);
-    this->op3p()->iterateListBackwards(v,vup);
-    this->op4p()->iterateListBackwards(v,vup);
+void AstNode::iterateChildrenBackwards(AstNVisitor& 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::iterateAndNextConst(AstNVisitor& v, AstNUser* vup) {
+void AstNode::iterateAndNextConst(AstNVisitor& v) {
    // Keep following the current list even if edits change it
-    if (!this) return;
-    for (AstNode* nodep=this; nodep; ) {
+    if (!this) return;  // A few cases could be cleaned up, but want symmetry with iterateAndNext
+    for (AstNode* nodep=this; nodep; ) {   // effectively: if (!this) return;  // Callers rely on this
 	AstNode* nnextp = nodep->m_nextp;
 	ASTNODE_PREFETCH(nnextp);
-	nodep->accept(v, vup);
+	nodep->accept(v);
 	nodep = nnextp;
    }
 }

-AstNode* AstNode::acceptSubtreeReturnEdits(AstNVisitor& v, AstNUser* vup) {
+AstNode* AstNode::iterateSubtreeReturnEdits(AstNVisitor& v) {
    // Some visitors perform tree edits (such as V3Const), and may even
    // replace/delete the exact nodep that the visitor is called with.  If
    // this happens, the parent will lose the handle to the node that was
@@ -823,12 +830,12 @@ AstNode* AstNode::acceptSubtreeReturnEdits(AstNVisitor& v, AstNUser* vup) {
    AstNode* nodep = this;  // Note "this" may point to bogus point later in this function
    if (nodep->castNetlist()) {
 	// Calling on top level; we know the netlist won't get replaced
-	nodep->accept(v, vup);
+	nodep->accept(v);
    } else if (!nodep->backp()) {
 	// Calling on standalone tree; insert a shim node so we can keep track, then delete it on completion
 	AstBegin* tempp = new AstBegin(nodep->fileline(),"[EditWrapper]",nodep);
 	{
-	    tempp->stmtsp()->accept(v, vup); VL_DANGLING(nodep); // nodep to null as may be replaced
+	    tempp->stmtsp()->accept(v); VL_DANGLING(nodep); // nodep to null as may be replaced
 	}
 	nodep = tempp->stmtsp()->unlinkFrBackWithNext();
 	tempp->deleteTree(); VL_DANGLING(tempp);
@@ -842,7 +849,7 @@ AstNode* AstNode::acceptSubtreeReturnEdits(AstNVisitor& v, AstNUser* vup) {
 	else if (this->m_backp->m_nextp == this) nextnodepp = &(this->m_backp->m_nextp);
 	if (!nextnodepp) this->v3fatalSrc("Node's back doesn't point to forward to node itself");
 	{
-	    nodep->accept(v, vup); VL_DANGLING(nodep); // nodep to null as may be replaced
+	    nodep->accept(v); VL_DANGLING(nodep); // nodep to null as may be replaced
 	}
 	nodep = *nextnodepp;  // Grab new node from point where old was connected
    }
@@ -852,16 +859,16 @@ AstNode* AstNode::acceptSubtreeReturnEdits(AstNVisitor& v, AstNUser* vup) {
 //======================================================================

 void AstNode::cloneRelinkTree() {
-    if (!this) return;
+    // private: Cleanup clone() operation on whole tree. Publicly call cloneTree() instead.
    for (AstNode* nodep=this; nodep; nodep=nodep->m_nextp) {
 	if (m_dtypep && m_dtypep->clonep()) {
-	    m_dtypep = m_dtypep->clonep()->castNodeDType();
+	    m_dtypep = m_dtypep->clonep();
 	}
 	nodep->cloneRelink();
-	nodep->m_op1p->cloneRelinkTree();
-	nodep->m_op2p->cloneRelinkTree();
-	nodep->m_op3p->cloneRelinkTree();
-	nodep->m_op4p->cloneRelinkTree();
+	if (nodep->m_op1p) nodep->m_op1p->cloneRelinkTree();
+	if (nodep->m_op2p) nodep->m_op2p->cloneRelinkTree();
+	if (nodep->m_op3p) nodep->m_op3p->cloneRelinkTree();
+	if (nodep->m_op4p) nodep->m_op4p->cloneRelinkTree();
    }
 }

@@ -869,37 +876,37 @@ void AstNode::cloneRelinkTree() {
 // Comparison

 bool AstNode::gateTreeIter() {
-    // Return true if the two trees are identical
-    if (this==NULL) return true;
+    // private: Return true if the two trees are identical
    if (!isGateOptimizable()) return false;
-    return (this->op1p()->gateTreeIter()
-	    && this->op2p()->gateTreeIter()
-	    && this->op3p()->gateTreeIter()
-	    && this->op4p()->gateTreeIter());
+    if (m_op1p && !m_op1p->gateTreeIter()) return false;
+    if (m_op2p && !m_op2p->gateTreeIter()) return false;
+    if (m_op3p && !m_op3p->gateTreeIter()) return false;
+    if (m_op4p && !m_op4p->gateTreeIter()) return false;
+    return true;
 }

-bool AstNode::sameTreeIter(AstNode* node2p, bool ignNext, bool gateOnly) {
-    // Return true if the two trees are identical
-    if (this==NULL && node2p==NULL) return true;
-    if (this==NULL || node2p==NULL) return false;
-    if (this->type() != node2p->type()
-	|| this->dtypep() != node2p->dtypep()
-	|| !this->same(node2p)
-	|| (gateOnly && !this->isGateOptimizable())) {
+bool AstNode::sameTreeIter(AstNode* node1p, AstNode* node2p, bool ignNext, bool gateOnly) {
+    // 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;
    }
-    return (this->op1p()->sameTreeIter(node2p->op1p(),false,gateOnly)
-	    && this->op2p()->sameTreeIter(node2p->op2p(),false,gateOnly)
-	    && this->op3p()->sameTreeIter(node2p->op3p(),false,gateOnly)
-	    && this->op4p()->sameTreeIter(node2p->op4p(),false,gateOnly)
-	    && (ignNext || this->nextp()->sameTreeIter(node2p->nextp(),false,gateOnly))
+    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)
+	    && sameTreeIter(node1p->m_op4p, node2p->m_op4p,false,gateOnly)
+	    && (ignNext || sameTreeIter(node1p->m_nextp, node2p->m_nextp,false,gateOnly))
 	);
 }

 //======================================================================
 // Static utilities

-ostream& operator<<(ostream& os, V3Hash rhs) {
+ostream& operator<<(ostream& os, const V3Hash& rhs) {
    return os<<hex<<setw(2)<<setfill('0')<<rhs.depth()
 	     <<"_"<<setw(6)<<setfill('0')<<rhs.hshval();
 }
@@ -916,6 +923,7 @@ V3Hash::V3Hash(const string& name) {
 // Debugging

 void AstNode::checkTreeIter(AstNode* backp) {
+    // private: Check a tree and children
    if (backp != this->backp()) {
 	this->v3fatalSrc("Back node inconsistent");
    }
@@ -924,15 +932,15 @@ void AstNode::checkTreeIter(AstNode* backp) {
 	if (op1p()||op2p()||op3p()||op4p())
 	    this->v3fatalSrc("Terminal operation with non-terminals");
    }
-    if (op1p()) op1p()->checkTreeIterList(this);
-    if (op2p()) op2p()->checkTreeIterList(this);
-    if (op3p()) op3p()->checkTreeIterList(this);
-    if (op4p()) op4p()->checkTreeIterList(this);
+    if (m_op1p) m_op1p->checkTreeIterList(this);
+    if (m_op2p) m_op2p->checkTreeIterList(this);
+    if (m_op3p) m_op3p->checkTreeIterList(this);
+    if (m_op4p) m_op4p->checkTreeIterList(this);
 }

 void AstNode::checkTreeIterList(AstNode* backp) {
-    // Check a (possible) list of nodes, this is always the head of the list
-    if (!this) v3fatalSrc("Null nodep");
+    // private: Check a (possible) list of nodes, this is always the head of the list
+    // Audited to make sure this is never NULL
    AstNode* headp = this;
    AstNode* tailp = this;
    for (AstNode* nodep=headp; nodep; nodep=nodep->nextp()) {
@@ -946,7 +954,6 @@ void AstNode::checkTreeIterList(AstNode* backp) {
 }

 void AstNode::checkTree() {
-    if (!this) return;
    if (!debug()) return;
    if (this->backp()) {
 	// Linked tree- check only the passed node
@@ -957,17 +964,17 @@ void AstNode::checkTree() {
 }

 void AstNode::dumpGdb() {  // For GDB only
-    if (!this) { cout<<"This=NULL"<<endl; return; }
+    if (!dynamic_cast<const AstNode*>(this)) { cout<<"This=NULL"<<endl; return; }
    dumpGdbHeader();
    cout<<"  "; dump(cout); cout<<endl;
 }
 void AstNode::dumpGdbHeader() const {  // For GDB only
-    if (!this) { cout<<"This=NULL"<<endl; return; }
+    if (!dynamic_cast<const AstNode*>(this)) { cout<<"This=NULL"<<endl; return; }
    dumpPtrs(cout);
    cout<<"  Fileline = "<<fileline()<<endl;
 }
 void AstNode::dumpTreeGdb() {  // For GDB only
-    if (!this) { cout<<"This=NULL"<<endl; return; }
+    if (!dynamic_cast<const AstNode*>(this)) { cout<<"This=NULL"<<endl; return; }
    dumpGdbHeader();
    dumpTree(cout);
 }
@@ -1007,7 +1014,6 @@ void AstNode::dumpPtrs(ostream& os) const {
 }

 void AstNode::dumpTree(ostream& os, const string& indent, int maxDepth) {
-    if (!this) return;
    os<<indent<<" "<<this<<endl;
    if (debug()>8) { os<<indent<<"     "; dumpPtrs(os); }
    if (maxDepth==1) {
@@ -1021,7 +1027,7 @@ void AstNode::dumpTree(ostream& os, const string& indent, int maxDepth) {
 }

 void AstNode::dumpTreeAndNext(ostream& os, const string& indent, int maxDepth) {
-    if (!this) return;
+    // Audited to make sure this is never NULL
    for (AstNode* nodep=this; nodep; nodep=nodep->nextp()) {
 	nodep->dumpTree(os, indent, maxDepth);
    }
@@ -1031,7 +1037,7 @@ void AstNode::dumpTreeFile(const string& filename, bool append, bool doDump) {
    if (doDump) {
 	{   // Write log & close
 	    UINFO(2,"Dumping "<<filename<<endl);
-	    const VL_UNIQUE_PTR<ofstream> logsp (V3File::new_ofstream(filename, append));
+	    const vl_unique_ptr<ofstream> logsp (V3File::new_ofstream(filename, append));
 	    if (logsp->fail()) v3fatalSrc("Can't write "<<filename);
 	    *logsp<<"Verilator Tree Dump (format 0x3900) from <e"<<dec<<editCountLast()<<">";
 	    *logsp<<" to <e"<<dec<<editCountGbl()<<">"<<endl;
@@ -1055,8 +1061,16 @@ void AstNode::dumpTreeFile(const string& filename, bool append, bool doDump) {
    editCountSetLast();
 }

+void AstNode::v3errorEndFatal(ostringstream& str) const { v3errorEnd(str); assert(0); }
+
 void AstNode::v3errorEnd(ostringstream& str) const {
-    if (this && m_fileline) {
+    if (!dynamic_cast<const AstNode*>(this)) {
+	// No known cases cause this, but better than a core dump
+	if (debug()) UINFO(0, "-node: NULL. Please report this along with a --gdbbt backtrace as a Verilator bug.\n");
+	V3Error::v3errorEnd(str);
+    } else if (!m_fileline) {
+	V3Error::v3errorEnd(str);
+    } else {
 	ostringstream nsstr;
 	nsstr<<str.str();
 	if (debug()) {
@@ -1064,14 +1078,11 @@ void AstNode::v3errorEnd(ostringstream& str) const {
 	    nsstr<<"-node: "; ((AstNode*)this)->dump(nsstr); nsstr<<endl;
 	}
 	m_fileline->v3errorEnd(nsstr);
-    } else {
-	V3Error::v3errorEnd(str);
    }
 }

 string AstNode::warnMore() const {
-    if (this) return this->fileline()->warnMore();
-    else return V3Error::warnMore();
+    return fileline()->warnMore();
 }

 //======================================================================
@@ -6,7 +6,7 @@
 //
 //*************************************************************************
 //
-// Copyright 2003-2015 by Wilson Snyder.  This program is free software; you can
+// Copyright 2003-2017 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.
@@ -61,7 +61,7 @@ public:
  inline bool operator== (AstType lhs, AstType rhs) { return (lhs.m_e == rhs.m_e); }
  inline bool operator== (AstType lhs, AstType::en rhs) { return (lhs.m_e == rhs); }
  inline bool operator== (AstType::en lhs, AstType rhs) { return (lhs == rhs.m_e); }
-  inline ostream& operator<<(ostream& os, AstType rhs) { return os<<rhs.ascii(); }
+  inline ostream& operator<<(ostream& os, const AstType& rhs) { return os<<rhs.ascii(); }

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

@@ -82,7 +82,7 @@ public:
    };
    enum en m_e;
    const char* ascii() const {
-	static const char* names[] = {
+	static const char* const names[] = {
 	    "UNSIGNED","SIGNED","NOSIGN"
 	};
 	return names[m_e];
@@ -107,7 +107,7 @@ public:
  inline bool operator== (AstNumeric lhs, AstNumeric rhs) { return (lhs.m_e == rhs.m_e); }
  inline bool operator== (AstNumeric lhs, AstNumeric::en rhs) { return (lhs.m_e == rhs); }
  inline bool operator== (AstNumeric::en lhs, AstNumeric rhs) { return (lhs == rhs.m_e); }
-  inline ostream& operator<<(ostream& os, AstNumeric rhs) { return os<<rhs.ascii(); }
+  inline ostream& operator<<(ostream& os, const AstNumeric& rhs) { return os<<rhs.ascii(); }

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

@@ -203,19 +203,42 @@ public:
 	return AstEdgeType::ET_ILLEGAL;
    }
    const char* ascii() const {
-	static const char* names[] = {
+	static const char* const names[] = {
 	    "%E-edge", "ANY", "BOTH", "POS", "NEG", "HIGH", "LOW",
 	    "COMBO","INITIAL","SETTLE","NEVER"
 	};
 	return names[m_e];
-    };
+    }
    const char* verilogKwd() const {
-	static const char* names[] = {
+	static const char* const names[] = {
 	    "%E-edge", "[any]", "edge", "posedge", "negedge", "[high]","[low]",
 	    "*","[initial]","[settle]","[never]"
 	};
 	return names[m_e];
-    };
+    }
+    // Return true iff this and the other have mutually exclusive transitions
+    bool exclusiveEdge(const AstEdgeType& other) const {
+        switch (m_e) {
+        case AstEdgeType::ET_POSEDGE:
+            switch (other.m_e) {
+            case AstEdgeType::ET_NEGEDGE:  // FALLTHRU
+            case AstEdgeType::ET_LOWEDGE:
+                return true;
+            default: {}
+            }
+            break;
+        case AstEdgeType::ET_NEGEDGE:
+            switch (other.m_e) {
+            case AstEdgeType::ET_POSEDGE:  // FALLTHRU
+            case AstEdgeType::ET_HIGHEDGE:
+                return true;
+            default: {}
+            }
+            break;
+        default: {}
+        }
+        return false;
+    }
    inline AstEdgeType () : m_e(ET_ILLEGAL) {}
    // cppcheck-suppress noExplicitConstructor
    inline AstEdgeType (en _e) : m_e(_e) {}
@@ -270,7 +293,7 @@ public:
    };
    enum en m_e;
    const char* ascii() const {
-	static const char* names[] = {
+	static const char* const names[] = {
 	    "%E-AT",
 	    "DIM_BITS", "DIM_DIMENSIONS", "DIM_HIGH", "DIM_INCREMENT", "DIM_LEFT",
 	    "DIM_LOW", "DIM_RIGHT", "DIM_SIZE", "DIM_UNPK_DIMENSIONS",
@@ -315,7 +338,7 @@ public:
    };
    enum en m_e;
    const char* ascii() const {
-	static const char* names[] = {
+	static const char* const names[] = {
 	    "%E-unk",
 	    "bit", "byte", "chandle", "int", "integer", "logic", "longint",
 	    "real", "shortint", "shortreal", "time",
@@ -328,7 +351,7 @@ public:
 	return names[m_e];
    };
    const char* dpiType() const {
-	static const char* names[] = {
+	static const char* const names[] = {
 	    "%E-unk",
 	    "unsigned char", "char", "void*", "int", "int", "svLogic", "long long",
 	    "double", "short int", "float", "long long",
@@ -340,7 +363,7 @@ public:
 	};
 	return names[m_e];
    };
-    static void test() {
+    static void selfTest() {
 	UASSERT(0==strcmp(AstBasicDTypeKwd(_ENUM_MAX).ascii()," MAX"),"Enum array mismatch");
 	UASSERT(0==strcmp(AstBasicDTypeKwd(_ENUM_MAX).dpiType()," MAX"),"Enum array mismatch");
    }
@@ -396,7 +419,7 @@ public:
 	return (m_e==LOGIC || m_e==BIT);
    }
    bool isDpiUnsupported() const {
-	return (m_e==LOGIC || m_e==TIME);
+	return (m_e==TIME);
    }
    bool isDpiUnsignable() const {  // Can add "unsigned" to DPI
 	return (m_e==BYTE || m_e==SHORTINT || m_e==INT || m_e==LONGINT || m_e==INTEGER);
@@ -427,6 +450,7 @@ public:
 	SUPPLY0,
 	SUPPLY1,
 	WIRE,
+	WREAL,
 	IMPLICITWIRE,
 	TRIWIRE,
 	TRI0,
@@ -445,16 +469,16 @@ public:
    explicit inline AstVarType (int _e) : m_e(static_cast<en>(_e)) {}
    operator en () const { return m_e; }
    const char* ascii() const {
-	static const char* names[] = {
+	static const char* const names[] = {
 	    "?","GPARAM","LPARAM","GENVAR",
 	    "VAR","INPUT","OUTPUT","INOUT",
-	    "SUPPLY0","SUPPLY1","WIRE","IMPLICITWIRE",
+	    "SUPPLY0","SUPPLY1","WIRE","WREAL","IMPLICITWIRE",
 	    "TRIWIRE","TRI0","TRI1",
 	    "PORT",
 	    "BLOCKTEMP","MODULETEMP","STMTTEMP","XTEMP",
 	    "IFACEREF"};
 	return names[m_e]; }
-    bool isSignal() const  { return (m_e==WIRE || m_e==IMPLICITWIRE
+    bool isSignal() const  { return (m_e==WIRE || m_e==WREAL || m_e==IMPLICITWIRE
 				     || m_e==TRIWIRE
 				     || m_e==TRI0 || m_e==TRI1
 				     || m_e==SUPPLY0 || m_e==SUPPLY1
@@ -463,7 +487,7 @@ public:
  inline bool operator== (AstVarType lhs, AstVarType rhs) { return (lhs.m_e == rhs.m_e); }
  inline bool operator== (AstVarType lhs, AstVarType::en rhs) { return (lhs.m_e == rhs); }
  inline bool operator== (AstVarType::en lhs, AstVarType rhs) { return (lhs == rhs.m_e); }
-  inline ostream& operator<<(ostream& os, AstVarType rhs) { return os<<rhs.ascii(); }
+  inline ostream& operator<<(ostream& os, const AstVarType& rhs) { return os<<rhs.ascii(); }

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

@@ -488,14 +512,14 @@ public:
 	else return m_e;
    }
    const char* ascii() const {
-	static const char* names[] = {
+	static const char* const names[] = {
 	    "","VL_LIKELY","VL_UNLIKELY"};
 	return names[m_e]; }
  };
  inline bool operator== (AstBranchPred lhs, AstBranchPred rhs) { return (lhs.m_e == rhs.m_e); }
  inline bool operator== (AstBranchPred lhs, AstBranchPred::en rhs) { return (lhs.m_e == rhs); }
  inline bool operator== (AstBranchPred::en lhs, AstBranchPred rhs) { return (lhs == rhs.m_e); }
-  inline ostream& operator<<(ostream& os, AstBranchPred rhs) { return os<<rhs.ascii(); }
+  inline ostream& operator<<(ostream& os, const AstBranchPred& rhs) { return os<<rhs.ascii(); }

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

@@ -514,20 +538,21 @@ public:
    inline AstVarAttrClocker (en _e) : m_e(_e) {}
    explicit inline AstVarAttrClocker (int _e) : m_e(static_cast<en>(_e)) {}
    operator en () const { return m_e; }
+    bool unknown() const { return m_e==CLOCKER_UNKNOWN; }
    AstVarAttrClocker invert() const {
 	if (m_e==CLOCKER_YES) return CLOCKER_NO;
 	else if (m_e==CLOCKER_NO) return CLOCKER_YES;
 	else return m_e;
    }
    const char* ascii() const {
-	static const char* names[] = {
+	static const char* const names[] = {
 	    "","clker","non_clker"};
 	return names[m_e]; }
  };
  inline bool operator== (AstVarAttrClocker lhs, AstVarAttrClocker rhs) { return (lhs.m_e == rhs.m_e); }
  inline bool operator== (AstVarAttrClocker lhs, AstVarAttrClocker::en rhs) { return (lhs.m_e == rhs); }
  inline bool operator== (AstVarAttrClocker::en lhs, AstVarAttrClocker rhs) { return (lhs == rhs.m_e); }
-  inline ostream& operator<<(ostream& os, AstVarAttrClocker rhs) { return os<<rhs.ascii(); }
+  inline ostream& operator<<(ostream& os, const AstVarAttrClocker& rhs) { return os<<rhs.ascii(); }

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

@@ -546,7 +571,7 @@ public:
    explicit inline VAlwaysKwd (int _e) : m_e(static_cast<en>(_e)) {}
    operator en () const { return m_e; }
    const char* ascii() const {
-	static const char* names[] = {
+	static const char* const names[] = {
 	    "always","always_ff","always_latch","always_comb"};
 	return names[m_e]; }
  };
@@ -596,7 +621,7 @@ public:
    bool addNewline() const { return m_e!=DT_WRITE; }
    bool needScopeTracking() const { return m_e!=DT_DISPLAY && m_e!=DT_WRITE; }
    const char* ascii() const {
-	static const char* names[] = {
+	static const char* const names[] = {
 	    "display","write","info","error","warning","fatal"};
 	return names[m_e]; }
  };
@@ -619,14 +644,14 @@ public:
    explicit inline AstParseRefExp (int _e) : m_e(static_cast<en>(_e)) {}
    operator en () const { return m_e; }
    const char* ascii() const {
-	static const char* names[] = {
+	static const char* const names[] = {
 	    "","TEXT","PREDOT"};
 	return names[m_e]; }
  };
  inline bool operator== (AstParseRefExp lhs, AstParseRefExp rhs) { return (lhs.m_e == rhs.m_e); }
  inline bool operator== (AstParseRefExp lhs, AstParseRefExp::en rhs) { return (lhs.m_e == rhs); }
  inline bool operator== (AstParseRefExp::en lhs, AstParseRefExp rhs) { return (lhs == rhs.m_e); }
-  inline ostream& operator<<(ostream& os, AstParseRefExp rhs) { return os<<rhs.ascii(); }
+  inline ostream& operator<<(ostream& os, const AstParseRefExp& rhs) { return os<<rhs.ascii(); }

 //######################################################################
 // VNumRange - Structure containing numberic range information
@@ -656,10 +681,14 @@ struct VNumRange {
 	return false;
    }
    //
+    class LeftRight {};
    VNumRange() : m_hi(0), m_lo(0), mu_flags(0) {}
    VNumRange(int hi, int lo, bool littleEndian)
 	: m_hi(0), m_lo(0), mu_flags(0)
 	{ init(hi,lo,littleEndian); }
+    VNumRange(LeftRight, int left, int right)
+        : m_hi(0), m_lo(0), mu_flags(0)
+        { init((right>left)?right:left, (right>left)?left:right, (right>left)); }
    ~VNumRange() {}
    // MEMBERS
    void init(int hi, int lo, bool littleEndian) {
@@ -678,7 +707,7 @@ struct VNumRange {
 	{ return (!m_ranged || (m_lo==0 && m_hi>=1 && !m_littleEndian)); }
    void dump(ostream& str) const { if (ranged()) str<<"["<<left()<<":"<<right()<<"]"; else str<<"[norg]"; }
 };
-inline ostream& operator<<(ostream& os, VNumRange rhs) { rhs.dump(os); return os; }
+inline ostream& operator<<(ostream& os, const VNumRange& rhs) { rhs.dump(os); return os; }

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

@@ -707,14 +736,14 @@ struct VBasicTypeKey {
 	if (!(m_nrange == rhs.m_nrange)) return false;  // lhs > rhs
 	return false; }
    VBasicTypeKey(int width, int widthMin, AstNumeric numeric, AstBasicDTypeKwd kwd,
-	     VNumRange nrange)
+		  const VNumRange& nrange)
 	: m_width(width), m_widthMin(widthMin), m_numeric(numeric),
 	  m_keyword(kwd), m_nrange(nrange) {}
    ~VBasicTypeKey() {}
 };

 //######################################################################
-// AstNUser - Generic pointer base class for AST User nodes.
+// AstNUser - Generic base class for AST User nodes.
 //	    - Also used to allow parameter passing up/down iterate calls

 class WidthVP;
@@ -723,26 +752,32 @@ class OrderBlockNU;
 class OrderVarNU;
 class V3GraphVertex;
 class VSymEnt;
-struct AstNUser {
-    AstNUser*	p() { return this; }	// So can take address of temporary: iterate(...,AstNUser(args).p())
+
+class VNUser {
+    union {
+	void* up;
+	int ui;
+    } m_u;
+public:
+    VNUser() {}
+    // non-explicit:
+    // cppcheck-suppress noExplicitConstructor
+    VNUser(int i) { m_u.up = 0; m_u.ui = i; }
+    explicit VNUser(void* p) { m_u.up = p; }
+    ~VNUser() {}
    // Casters
-    WidthVP*	c() { return ((WidthVP*)this); }
-    LinkVP*	castLinkVP() { return ((LinkVP*)this); }
-    VSymEnt*	castSymEnt() { return ((VSymEnt*)this); }
-    AstNode*	castNode() { return ((AstNode*)this); }
-    OrderBlockNU* castOrderBlock() { return ((OrderBlockNU*)this); }
-    OrderVarNU*	castOrderVar() { return ((OrderVarNU*)this); }
-    V3GraphVertex* castGraphVertex() { return ((V3GraphVertex*)this); }
-    inline int	castInt() {
-	union { AstNUser* up; int ui; } u;
-	u.up = this;
-	return u.ui;
-    }
-    static inline AstNUser* fromInt (int i) {
-	union { AstNUser* up; int ui; } u;
-	u.up=0; u.ui=i;
-	return u.up;
+    WidthVP*	c() { return ((WidthVP*)m_u.up); }
+    LinkVP*	toLinkVP() { return ((LinkVP*)m_u.up); }
+    VSymEnt*	toSymEnt() { return ((VSymEnt*)m_u.up); }
+    AstNode*	toNodep() { return ((AstNode*)m_u.up); }
+    OrderBlockNU* toOrderBlock() { return ((OrderBlockNU*)m_u.up); }
+    OrderVarNU*	toOrderVar() { return ((OrderVarNU*)m_u.up); }
+    V3GraphVertex* toGraphVertex() { return ((V3GraphVertex*)m_u.up); }
+    inline int	toInt() {
+	return m_u.ui;
    }
+    static inline VNUser fromZero () { return VNUser(0); }
+    static inline VNUser fromInt (int i) { return VNUser(i); }
 };

 //######################################################################
@@ -861,7 +896,8 @@ public:
    }
 #include "V3Ast__gen_visitor.h"	// From ./astgen
    // Things like:
-    //  virtual void visit(type*) = 0;
+    //  virtual void visit(AstBreak* nodep) { visit((AstNodeStmt*)(nodep)); }
+    //  virtual void visit(AstNodeStmt* nodep) { visit((AstNode*)(nodep)); }
 };

 //######################################################################
@@ -884,7 +920,7 @@ public:
    AstNode* oldp() const { return m_oldp; }
    void dump(ostream& str=cout) const;
 };
-inline ostream& operator<<(ostream& os, AstNRelinker& rhs) { rhs.dump(os); return os;}
+inline ostream& operator<<(ostream& os, const AstNRelinker& rhs) { rhs.dump(os); return os;}

 //######################################################################
 // V3Hash -- Node hashing for V3Combine
@@ -896,7 +932,8 @@ class V3Hash {
    uint32_t	m_both;
    static const uint32_t M24 = ((1<<24)-1);
    void setBoth(uint32_t depth, uint32_t hshval) {
-	if (depth==0) depth=1; if (depth>255) depth=255;
+	if (depth==0) depth=1;
+	if (depth>255) depth=255;
 	m_both = (depth<<24) | (hshval & M24);
    }
 public:
@@ -909,12 +946,12 @@ public:
    inline bool operator== (const V3Hash& rh) const { return m_both==rh.m_both; }
    inline bool operator!= (const V3Hash& rh) const { return m_both!=rh.m_both; }
    inline bool operator< (const V3Hash& rh) const { return m_both<rh.m_both; }
-    // CREATORS
+    // CONSTRUCTORS
    class Illegal {};		// for creator type-overload selection
    class FullValue {};		// for creator type-overload selection
    explicit V3Hash(Illegal) { m_both=0; }
    // Saving and restoring inside a userp
-    explicit V3Hash(AstNUser* up) { m_both=up->castInt(); }
+    explicit V3Hash(VNUser u) { m_both=u.toInt(); }
    V3Hash operator+= (const V3Hash& rh) {
 	setBoth(depth()+rh.depth(), (hshval()*31+rh.hshval()));
 	return *this; };
@@ -933,7 +970,7 @@ public:
    V3Hash(V3Hash h1, V3Hash h2, V3Hash h3, V3Hash h4) {
 	setBoth(1,((h1.hshval()*31+h2.hshval())*31+h3.hshval())*31+h4.hshval()); }
 };
-ostream& operator<<(ostream& os, V3Hash rhs);
+ostream& operator<<(ostream& os, const V3Hash& rhs);

 //######################################################################
 // AstNode -- Base type of all Ast types
@@ -973,15 +1010,15 @@ class AstNode {
    //		// Space for more bools here

    // This member ordering both allows 64 bit alignment and puts associated data together
-    AstNUser*	m_user1p;	// Pointer to any information the user iteration routine wants
+    VNUser	m_user1u;	// Contains any information the user iteration routine wants
    uint32_t	m_user1Cnt;	// Mark of when userp was set
    uint32_t	m_user2Cnt;	// Mark of when userp was set
-    AstNUser*	m_user2p;	// Pointer to any information the user iteration routine wants
-    AstNUser*	m_user3p;	// Pointer to any information the user iteration routine wants
+    VNUser	m_user2u;	// Contains any information the user iteration routine wants
+    VNUser	m_user3u;	// Contains any information the user iteration routine wants
    uint32_t	m_user3Cnt;	// Mark of when userp was set
    uint32_t	m_user4Cnt;	// Mark of when userp was set
-    AstNUser*	m_user4p;	// Pointer to any information the user iteration routine wants
-    AstNUser*	m_user5p;	// Pointer to any information the user iteration routine wants
+    VNUser	m_user4u;	// Contains any information the user iteration routine wants
+    VNUser	m_user5u;	// Contains any information the user iteration routine wants
    uint32_t	m_user5Cnt;	// Mark of when userp was set

    // METHODS
@@ -991,17 +1028,17 @@ class AstNode {
    void	op4p(AstNode* nodep) { m_op4p = nodep; if (nodep) nodep->m_backp = this; }

    void	init();	// initialize value of AstNode
-    void	iterateListBackwards(AstNVisitor& v, AstNUser* vup=NULL);
+    void	iterateListBackwards(AstNVisitor& v);
 private:
    AstNode*	cloneTreeIter();
    AstNode*	cloneTreeIterList();
    void	checkTreeIter(AstNode* backp);
    void	checkTreeIterList(AstNode* backp);
    bool	gateTreeIter();
-    bool	sameTreeIter(AstNode* node2p, bool ignNext, bool gateOnly);
+    bool	sameTreeIter(AstNode* node1p, AstNode* node2p, bool ignNext, bool gateOnly);
    void	deleteTreeIter();
-public:
    void	deleteNode();
+public:
    static void	relinkOneLink(AstNode*& pointpr, AstNode* newp);
    // cppcheck-suppress functionConst
    void	debugTreeChange(const char* prefix, int lineno, bool next);
@@ -1078,6 +1115,8 @@ public:
    // ACCESSORS
    virtual string name() const { return ""; }
    virtual void name(const string& name) { this->v3fatalSrc("name() called on object without name() method"); }
+    virtual void tag(const string& text) {}
+    virtual string tag() const { return ""; }
    virtual string verilogKwd() const { return ""; }
    string 	shortName() const;	// Name with __PVT__ removed for concatenating scopes
    static string dedotName(const string& namein);	// Name with dots removed
@@ -1109,57 +1148,75 @@ public:
    bool	isSigned() const;
    bool	isString() const;

-    AstNUser*	user1p() const {
+    VNUser	user1u() const {
 	// Slows things down measurably, so disabled by default
 	//UASSERT_STATIC(AstUser1InUse::s_userBusy, "userp set w/o busy");
-	return ((m_user1Cnt==AstUser1InUse::s_userCntGbl)?m_user1p:NULL);
+	return ((m_user1Cnt==AstUser1InUse::s_userCntGbl) ? m_user1u : VNUser(0));
    }
-    void	user1p(void* userp) { m_user1p=(AstNUser*)(userp); m_user1Cnt=AstUser1InUse::s_userCntGbl; }
-    int		user1() const { return user1p()->castInt(); }
-    void	user1(int val) { user1p(AstNUser::fromInt(val)); }
-    int		user1Inc() { int v=user1(); user1(v+1); return v; }
+    AstNode*	user1p() const { return user1u().toNodep(); }
+    void	user1u(const VNUser& user) { m_user1u=user; m_user1Cnt=AstUser1InUse::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()
    static void	user1ClearTree() { AstUser1InUse::clear(); }  // Clear userp()'s across the entire tree

-    AstNUser*	user2p() const {
-	//UASSERT_STATIC(AstUser2InUse::s_userBusy, "user2p set w/o busy");
-	return ((m_user2Cnt==AstUser2InUse::s_userCntGbl)?m_user2p:NULL); }
-    void	user2p(void* userp) { m_user2p=(AstNUser*)(userp); m_user2Cnt=AstUser2InUse::s_userCntGbl; }
-    int		user2() const { return user2p()->castInt(); }
-    void	user2(int val) { user2p(AstNUser::fromInt(val)); }
-    int		user2Inc() { int v=user2(); user2(v+1); return v; }
-    int		user2SetOnce() { int v=user2(); if (!v) user2(1); return v; }
-    static void	user2ClearTree() { AstUser2InUse::clear(); }
+    VNUser	user2u() const {
+	// Slows things down measurably, so disabled by default
+	//UASSERT_STATIC(AstUser2InUse::s_userBusy, "userp set w/o busy");
+	return ((m_user2Cnt==AstUser2InUse::s_userCntGbl) ? m_user2u : VNUser(0));
+    }
+    AstNode*	user2p() const { return user2u().toNodep(); }
+    void	user2u(const VNUser& user) { m_user2u=user; m_user2Cnt=AstUser2InUse::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()
+    static void	user2ClearTree() { AstUser2InUse::clear(); }  // Clear userp()'s across the entire tree

-    AstNUser*	user3p() const {
-	//UASSERT_STATIC(AstUser3InUse::s_userBusy, "user3p set w/o busy");
-	return ((m_user3Cnt==AstUser3InUse::s_userCntGbl)?m_user3p:NULL); }
-    void	user3p(void* userp) { m_user3p=(AstNUser*)(userp); m_user3Cnt=AstUser3InUse::s_userCntGbl; }
-    int		user3() const { return user3p()->castInt(); }
-    void	user3(int val) { user3p(AstNUser::fromInt(val)); }
-    int		user3Inc() { int v=user3(); user3(v+1); return v; }
-    int		user3SetOnce() { int v=user3(); if (!v) user3(1); return v; }
-    static void	user3ClearTree() { AstUser3InUse::clear(); }
+    VNUser	user3u() const {
+	// Slows things down measurably, so disabled by default
+	//UASSERT_STATIC(AstUser3InUse::s_userBusy, "userp set w/o busy");
+	return ((m_user3Cnt==AstUser3InUse::s_userCntGbl) ? m_user3u : VNUser(0));
+    }
+    AstNode*	user3p() const { return user3u().toNodep(); }
+    void	user3u(const VNUser& user) { m_user3u=user; m_user3Cnt=AstUser3InUse::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()
+    static void	user3ClearTree() { AstUser3InUse::clear(); }  // Clear userp()'s across the entire tree

-    AstNUser*	user4p() const {
-	//UASSERT_STATIC(AstUser4InUse::s_userBusy, "user4p set w/o busy");
-	return ((m_user4Cnt==AstUser4InUse::s_userCntGbl)?m_user4p:NULL); }
-    void	user4p(void* userp) { m_user4p=(AstNUser*)(userp); m_user4Cnt=AstUser4InUse::s_userCntGbl; }
-    int		user4() const { return user4p()->castInt(); }
-    void	user4(int val) { user4p(AstNUser::fromInt(val)); }
-    int		user4Inc() { int v=user4(); user4(v+1); return v; }
-    int		user4SetOnce() { int v=user4(); if (!v) user4(1); return v; }
-    static void	user4ClearTree() { AstUser4InUse::clear(); }
+    VNUser	user4u() const {
+	// Slows things down measurably, so disabled by default
+	//UASSERT_STATIC(AstUser4InUse::s_userBusy, "userp set w/o busy");
+	return ((m_user4Cnt==AstUser4InUse::s_userCntGbl) ? m_user4u : VNUser(0));
+    }
+    AstNode*	user4p() const { return user4u().toNodep(); }
+    void	user4u(const VNUser& user) { m_user4u=user; m_user4Cnt=AstUser4InUse::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()
+    static void	user4ClearTree() { AstUser4InUse::clear(); }  // Clear userp()'s across the entire tree

-    AstNUser*	user5p() const {
-	//UASSERT_STATIC(AstUser5InUse::s_userBusy, "user5p set w/o busy");
-	return ((m_user5Cnt==AstUser5InUse::s_userCntGbl)?m_user5p:NULL); }
-    void	user5p(void* userp) { m_user5p=(AstNUser*)(userp); m_user5Cnt=AstUser5InUse::s_userCntGbl; }
-    int		user5() const { return user5p()->castInt(); }
-    void	user5(int val) { user5p(AstNUser::fromInt(val)); }
-    int		user5Inc() { int v=user5(); user5(v+1); return v; }
-    int		user5SetOnce() { int v=user5(); if (!v) user5(1); return v; }
-    static void	user5ClearTree() { AstUser5InUse::clear(); }
+    VNUser	user5u() const {
+	// Slows things down measurably, so disabled by default
+	//UASSERT_STATIC(AstUser5InUse::s_userBusy, "userp set w/o busy");
+	return ((m_user5Cnt==AstUser5InUse::s_userCntGbl) ? m_user5u : VNUser(0));
+    }
+    AstNode*	user5p() const { return user5u().toNodep(); }
+    void	user5u(const VNUser& user) { m_user5u=user; m_user5Cnt=AstUser5InUse::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()
+    static void	user5ClearTree() { AstUser5InUse::clear(); }  // Clear userp()'s across the entire tree

    vluint64_t	editCount() const { return m_editCount; }
    void	editCountInc() { m_editCount = ++s_editCntGbl; }  // Preincrement, so can "watch AstNode::s_editCntGbl=##"
@@ -1205,14 +1262,17 @@ public:

    // METHODS - dump and error
    void	v3errorEnd(ostringstream& str) const;
+    void	v3errorEndFatal(ostringstream& str) const VL_ATTR_NORETURN;
    string	warnMore() const;
    virtual void dump(ostream& str=cout);
    void	dumpGdb(); // For GDB only
    void	dumpGdbHeader() const;

    // METHODS - Tree modifications
-    AstNode*	addNext(AstNode* newp);		// Returns this, adds to end of list
-    AstNode*	addNextNull(AstNode* newp);	// Returns this, adds to end of list, NULL is OK
+    static AstNode* addNext(AstNode* nodep, AstNode* newp);	// Returns nodep, adds newp to end of nodep's list
+    static AstNode* addNextNull(AstNode* nodep, AstNode* newp);	// Returns nodep, adds newp (maybe NULL) to end of nodep's list
+    inline AstNode* addNext(AstNode* newp) { return addNext(this, newp); }
+    inline AstNode* addNextNull(AstNode* newp) { return addNextNull(this, newp); }
    void	addNextHere(AstNode* newp);	// Adds after speced node
    void	addPrev(AstNode* newp) { replaceWith(newp); newp->addNext(this); }
    void	addHereThisAsNext(AstNode* newp); // Adds at old place of this, this becomes next
@@ -1228,7 +1288,7 @@ public:

    // METHODS - Iterate on a tree
    AstNode*	cloneTree(bool cloneNextLink);
-    bool	gateTree() { return gateTreeIter(); }  // Is tree gateOptimizable?
+    bool	gateTree() { return gateTreeIter(); }  // Is tree isGateOptimizable?
    bool	sameTree(AstNode* node2p);	// Does tree of this == node2p?
    bool	sameGateTree(AstNode* node2p);	// Does tree of this == node2p?, not allowing non-isGateOptimizable
    void	deleteTree();	// Always deletes the next link
@@ -1254,25 +1314,23 @@ public:
    virtual bool isUnlikely() const { return false; }	// Else $stop or similar statement which means an above IF statement is unlikely to be taken
    virtual int  instrCount() const { return 0; }
    virtual V3Hash sameHash() const { return V3Hash(V3Hash::Illegal()); }  // Not a node that supports it
-    virtual bool same(AstNode* otherp) const { return true; }
+    virtual bool same(const AstNode*) const { return true; }
    virtual bool hasDType() const { return false; }	// Iff has a data type; dtype() must be non null
    virtual AstNodeDType* getChildDTypep() const { return NULL; } // Iff has a non-null childDTypep(), as generic node function
    virtual bool maybePointedTo() const { return false; }  // Another AstNode* may have a pointer into this node, other then normal front/back/etc.
    virtual const char* broken() const { return NULL; }

    // INVOKERS
-    virtual void accept(AstNVisitor& v, AstNUser* vup=NULL) = 0;
-    void	iterate(AstNVisitor& v, AstNUser* vup=NULL) { this->accept(v,vup); } 	  // Does this; excludes following this->next
-    void	iterateAndNext(AstNVisitor& v, AstNUser* vup=NULL);
-    void	iterateAndNextConst(AstNVisitor& v, AstNUser* vup=NULL);
-    void	iterateAndNextIgnoreEdit(AstNVisitor& v, AstNUser* vup=NULL) { iterateAndNextConst(v, vup); }
-    void	iterateChildren(AstNVisitor& v, AstNUser* vup=NULL);  // Excludes following this->next
-    void	iterateChildrenBackwards(AstNVisitor& v, AstNUser* vup=NULL);  // Excludes following this->next
-    void	iterateChildrenConst(AstNVisitor& v, AstNUser* vup=NULL);  // Excludes following this->next
-    AstNode*	acceptSubtreeReturnEdits(AstNVisitor& v, AstNUser* vup=NULL);  // Return edited nodep; see comments in V3Ast.cpp
+    virtual void accept(AstNVisitor& v) = 0;
+    void	iterate(AstNVisitor& v) { this->accept(v); } 	  // Does this; excludes following this->next
+    void	iterateAndNext(AstNVisitor& v);
+    void	iterateAndNextConst(AstNVisitor& v);
+    void	iterateChildren(AstNVisitor& v);  // Excludes following this->next
+    void	iterateChildrenBackwards(AstNVisitor& v);  // Excludes following this->next
+    void	iterateChildrenConst(AstNVisitor& v);  // Excludes following this->next
+    AstNode*	iterateSubtreeReturnEdits(AstNVisitor& v);  // Return edited nodep; see comments in V3Ast.cpp

    // CONVERSION
-    AstNode*	castNode() { return this; }
 #include "V3Ast__gen_interface.h"	// From ./astgen
    // Things like:
    //  AstAlways*	castAlways();
@@ -1287,7 +1345,8 @@ inline void AstNRelinker::relink(AstNode* newp) { newp->AstNode::relink(this); }

 #define ASTNODE_BASE_FUNCS(name)	\
    virtual ~Ast ##name() {} \
-    Ast ##name * cloneTree(bool cloneNext) { return AstNode::cloneTree(cloneNext)->cast ##name(); }
+    Ast ##name * cloneTree(bool cloneNext) { return static_cast<Ast ##name *>(AstNode::cloneTree(cloneNext)); } \
+    Ast ##name * clonep() const { return static_cast<Ast ##name *>(AstNode::clonep()); }

 class AstNodeMath : public AstNode {
    // Math -- anything that's part of an expression tree
@@ -1315,7 +1374,7 @@ public:
    // Know no children, and hot function, so skip iterator for speed
    // See checkTreeIter also that asserts no children
    // cppcheck-suppress functionConst
-    void iterateChildren(AstNVisitor& v, AstNUser* vup=NULL) { }
+    void iterateChildren(AstNVisitor& v) { }
 };

 class AstNodeUniop : public AstNodeMath {
@@ -1326,7 +1385,7 @@ public:
 	dtypeFrom(lhsp);
 	setOp1p(lhsp); }
    ASTNODE_BASE_FUNCS(NodeUniop)
-    AstNode*	lhsp() 	const { return op1p()->castNode(); }
+    AstNode*	lhsp() 	const { return op1p(); }
    void	lhsp(AstNode* nodep)  { return setOp1p(nodep); }
    // METHODS
    virtual void numberOperate(V3Number& out, const V3Number& lhs) = 0; // Set out to evaluation of a AstConst'ed lhs
@@ -1337,7 +1396,7 @@ public:
    virtual bool stringFlavor() const { return false; }	// N flavor of nodes with both flavors?
    virtual int instrCount()	const { return widthInstrs(); }
    virtual V3Hash sameHash() const { return V3Hash(); }
-    virtual bool same(AstNode*) const { return true; }
+    virtual bool same(const AstNode*) const { return true; }
 };

 class AstNodeBiop : public AstNodeMath {
@@ -1347,8 +1406,10 @@ public:
 	: AstNodeMath(fl) {
 	setOp1p(lhs); setOp2p(rhs); }
    ASTNODE_BASE_FUNCS(NodeBiop)
-    AstNode*	lhsp() 	const { return op1p()->castNode(); }
-    AstNode*	rhsp() 	const { return op2p()->castNode(); }
+    virtual AstNode* cloneType(AstNode* lhsp, AstNode* rhsp)=0;	// Clone single node, just get same type back.
+    // ACCESSORS
+    AstNode*	lhsp() 	const { return op1p(); }
+    AstNode*	rhsp() 	const { return op2p(); }
    void	lhsp(AstNode* nodep)  { return setOp1p(nodep); }
    void	rhsp(AstNode* nodep)  { return setOp2p(nodep); }
    // METHODS
@@ -1362,7 +1423,7 @@ public:
    virtual bool stringFlavor() const { return false; }	// N flavor of nodes with both flavors?
    virtual int instrCount()	const { return widthInstrs(); }
    virtual V3Hash sameHash() const { return V3Hash(); }
-    virtual bool same(AstNode*) const { return true; }
+    virtual bool same(const AstNode*) const { return true; }
 };

 class AstNodeTriop : public AstNodeMath {
@@ -1372,9 +1433,9 @@ public:
 	: AstNodeMath(fl) {
 	setOp1p(lhs); setOp2p(rhs); setOp3p(ths); }
    ASTNODE_BASE_FUNCS(NodeTriop)
-    AstNode*	lhsp() 	const { return op1p()->castNode(); }
-    AstNode*	rhsp() 	const { return op2p()->castNode(); }
-    AstNode*	thsp() 	const { return op3p()->castNode(); }
+    AstNode*	lhsp() 	const { return op1p(); }
+    AstNode*	rhsp() 	const { return op2p(); }
+    AstNode*	thsp() 	const { return op3p(); }
    void	lhsp(AstNode* nodep)  { return setOp1p(nodep); }
    void	rhsp(AstNode* nodep)  { return setOp2p(nodep); }
    void	thsp(AstNode* nodep)  { return setOp3p(nodep); }
@@ -1388,7 +1449,7 @@ public:
    virtual bool sizeMattersThs() = 0; // True if output result depends on ths size
    virtual int instrCount()	const { return widthInstrs(); }
    virtual V3Hash sameHash() const { return V3Hash(); }
-    virtual bool same(AstNode*) const { return true; }
+    virtual bool same(const AstNode*) const { return true; }
 };

 class AstNodeBiCom : public AstNodeBiop {
@@ -1416,9 +1477,9 @@ public:
    ASTNODE_BASE_FUNCS(NodeCond)
    virtual void numberOperate(V3Number& out, const V3Number& lhs, const V3Number& rhs, const V3Number& ths) {
 	if (lhs.isNeqZero()) out.opAssign(rhs); else out.opAssign(ths); }
-    AstNode*	condp() 	const { return op1p()->castNode(); }	// op1 = Condition
-    AstNode*	expr1p() 	const { return op2p()->castNode(); }	// op2 = If true...
-    AstNode*	expr2p() 	const { return op3p()->castNode(); }	// op3 = If false...
+    AstNode*	condp() 	const { return op1p(); }	// op1 = Condition
+    AstNode*	expr1p() 	const { return op2p(); }	// op2 = If true...
+    AstNode*	expr2p() 	const { return op3p(); }	// op3 = If false...
    virtual string emitVerilog() { return "%k(%l %f? %r %k: %t)"; }
    virtual string emitC() { return "VL_COND_%nq%lq%rq%tq(%nw,%lw,%rw,%tw, %P, %li, %ri, %ti)"; }
    virtual bool cleanOut() { return false; } // clean if e1 & e2 clean
@@ -1427,6 +1488,7 @@ public:
    virtual bool sizeMattersLhs() { return false; } virtual bool sizeMattersRhs() { return false; }
    virtual bool sizeMattersThs() { return false; }
    virtual int instrCount()	const { return instrCountBranch(); }
+    virtual AstNode* cloneType(AstNode* condp, AstNode* expr1p, AstNode* expr2p) = 0;
 };

 class AstNodePreSel : public AstNode {
@@ -1436,10 +1498,10 @@ public:
 	: AstNode(fl) {
 	setOp1p(lhs); setOp2p(rhs); setNOp3p(ths); }
    ASTNODE_BASE_FUNCS(NodePreSel)
-    AstNode*	lhsp() 	const { return op1p()->castNode(); }
+    AstNode*	lhsp() 	const { return op1p(); }
    AstNode*	fromp() const { return lhsp(); }
-    AstNode*	rhsp() 	const { return op2p()->castNode(); }
-    AstNode*	thsp() 	const { return op3p()->castNode(); }
+    AstNode*	rhsp() 	const { return op2p(); }
+    AstNode*	thsp() 	const { return op3p(); }
    AstAttrOf*	attrp() const { return op4p()->castAttrOf(); }
    void	lhsp(AstNode* nodep)  { return setOp1p(nodep); }
    void	rhsp(AstNode* nodep)  { return setOp2p(nodep); }
@@ -1447,7 +1509,7 @@ public:
    void	attrp(AstAttrOf* nodep)  { return setOp4p((AstNode*)nodep); }
    // METHODS
    virtual V3Hash sameHash() const { return V3Hash(); }
-    virtual bool same(AstNode*) const { return true; }
+    virtual bool same(const AstNode*) const { return true; }
 };

 class AstNodeStmt : public AstNode {
@@ -1471,16 +1533,17 @@ public:
    ASTNODE_BASE_FUNCS(NodeAssign)
    virtual AstNode*	cloneType(AstNode* lhsp, AstNode* rhsp)=0;	// Clone single node, just get same type back.
    // So iteration hits the RHS which is "earlier" in execution order, it's op1, not op2
-    AstNode* rhsp()		const { return op1p()->castNode(); }	// op1 = Assign from
-    AstNode* lhsp()		const { return op2p()->castNode(); }	// op2 = Assign to
+    AstNode* rhsp()		const { return op1p(); }	// op1 = Assign from
+    AstNode* lhsp()		const { return op2p(); }	// op2 = Assign to
    void rhsp(AstNode* np) { setOp1p(np); }
    void lhsp(AstNode* np) { setOp2p(np); }
    virtual bool hasDType() const { return true; }
    virtual bool cleanRhs() { return true; }
    virtual int  instrCount() const { return widthInstrs(); }
    virtual V3Hash sameHash() const { return V3Hash(); }
-    virtual bool same(AstNode*) const { return true; }
+    virtual bool same(const AstNode*) const { return true; }
    virtual string verilogKwd() const { return "="; }
+    virtual bool brokeLhsMustBeLvalue() const = 0;
 };

 class AstNodeFor : public AstNodeStmt {
@@ -1491,14 +1554,14 @@ public:
 	addNOp1p(initsp); setOp2p(condp); addNOp3p(incsp); addNOp4p(bodysp);
    }
    ASTNODE_BASE_FUNCS(NodeFor)
-    AstNode*	initsp()	const { return op1p()->castNode(); }	// op1= initial statements
-    AstNode*	condp()		const { return op2p()->castNode(); }	// op2= condition to continue
-    AstNode*	incsp()		const { return op3p()->castNode(); }	// op3= increment statements
-    AstNode*	bodysp()	const { return op4p()->castNode(); }	// op4= body of loop
+    AstNode*	initsp()	const { return op1p(); }	// op1= initial statements
+    AstNode*	condp()		const { return op2p(); }	// op2= condition to continue
+    AstNode*	incsp()		const { return op3p(); }	// op3= increment statements
+    AstNode*	bodysp()	const { return op4p(); }	// op4= body of loop
    virtual bool isGateOptimizable() const { return false; }
    virtual int  instrCount() const { return instrCountBranch(); }
    virtual V3Hash sameHash() const { return V3Hash(); }
-    virtual bool same(AstNode* samep) const { return true; }
+    virtual bool same(const AstNode* samep) const { return true; }
 };

 class AstNodeIf : public AstNodeStmt {
@@ -1520,7 +1583,7 @@ public:
    virtual bool isGateDedupable() const { return true; }
    virtual int  instrCount() const { return instrCountBranch(); }
    virtual V3Hash sameHash() const { return V3Hash(); }
-    virtual bool same(AstNode* samep) const { return true; }
+    virtual bool same(const AstNode* samep) const { return true; }
    void    branchPred(AstBranchPred flag) { m_branchPred = flag; }
    AstBranchPred branchPred() const { return m_branchPred; }
 };
@@ -1533,9 +1596,9 @@ public:
    }
    ASTNODE_BASE_FUNCS(NodeCase)
    virtual int   instrCount()	const { return instrCountBranch(); }
-    AstNode*	  exprp()	const { return op1p()->castNode(); }	// op1 = case condition <expression>
+    AstNode*	  exprp()	const { return op1p(); }	// op1 = case condition <expression>
    AstCaseItem*  itemsp()	const { return op2p()->castCaseItem(); }  // op2 = list of case expressions
-    AstNode*	  notParallelp() const { return op3p()->castNode(); }	// op3 = assertion code for non-full case's
+    AstNode*	  notParallelp() const { return op3p(); }	// op3 = assertion code for non-full case's
    void addItemsp(AstNode* nodep) { addOp2p(nodep); }
    void addNotParallelp(AstNode* nodep) { setOp3p(nodep); }
 };
@@ -1597,7 +1660,7 @@ public:
    // Know no children, and hot function, so skip iterator for speed
    // See checkTreeIter also that asserts no children
    // cppcheck-suppress functionConst
-    void iterateChildren(AstNVisitor& v, AstNUser* vup=NULL) { }
+    void iterateChildren(AstNVisitor& v) { }
 };

 class AstNodeText : public AstNode {
@@ -1612,8 +1675,9 @@ public:
    ASTNODE_BASE_FUNCS(NodeText)
    virtual void dump(ostream& str=cout);
    virtual V3Hash sameHash() const { return V3Hash(text()); }
-    virtual bool same(AstNode* samep) const {
-	return text()==samep->castNodeText()->text(); }
+    virtual bool same(const AstNode* samep) const {
+	const AstNodeText* asamep = static_cast<const AstNodeText*>(samep);
+	return text() == asamep->text(); }
    const string& text() const { return m_text; }
 };

@@ -1647,6 +1711,8 @@ public:
    virtual bool maybePointedTo() const { return true; }
    virtual AstNodeDType* virtRefDTypep() const { return NULL; } // Iff has a non-null refDTypep(), as generic node function
    virtual void virtRefDTypep(AstNodeDType* nodep) { }	// Iff has refDTypep(), set as generic node function
+    virtual bool similarDType(AstNodeDType* samep) const = 0;  // Assignable equivalence.  Call skipRefp() on this and samep before calling
+    virtual AstNodeDType* subDTypep() const { return NULL; }  // Iff has a non-null subDTypep(), as generic node function
    //
    // Changing the width may confuse the data type resolution, so must clear TypeTable cache after use.
    void widthForce(int width, int sized) { m_width=width; m_widthMin=sized; }
@@ -1696,6 +1762,9 @@ public:
    virtual int widthAlignBytes() const; // (Slow) recurses - Structure alignment 1,2,4 or 8 bytes (arrays affect this)
    virtual int widthTotalBytes() const; // (Slow) recurses - Width in bytes rounding up 1,2,4,8,12,...
    // op1 = members
+    virtual bool similarDType(AstNodeDType* samep) const {
+	return this==samep;  // We don't compare members, require exact equivalence
+    }
    AstMemberDType* membersp() const { return op1p()->castMemberDType(); } // op1 = AstMember list
    void addMembersp(AstNode* nodep) { addNOp1p(nodep); }
    bool packed() const { return m_packed; }
@@ -1726,20 +1795,28 @@ public:
    virtual void dump(ostream& str);
    virtual void dumpSmall(ostream& str);
    virtual const char* broken() const { BROKEN_RTN(!((m_refDTypep && !childDTypep() && m_refDTypep->brokeExists())
-						     || (!m_refDTypep && childDTypep()))); return NULL; }
+						      || (!m_refDTypep && childDTypep()))); return NULL; }
    virtual void cloneRelink() { if (m_refDTypep && m_refDTypep->clonep()) {
-	m_refDTypep = m_refDTypep->clonep()->castNodeDType();
+	m_refDTypep = m_refDTypep->clonep();
    }}
-    virtual bool same(AstNode* samep) const {
-	AstNodeArrayDType* sp = samep->castNodeArrayDType();
-	return (msb()==sp->msb()
-		&& subDTypep()==sp->subDTypep()
-		&& rangenp()->sameTree(sp->rangenp())); }  // HashedDT doesn't recurse, so need to check children
+    virtual bool same(const AstNode* samep) const {
+	const AstNodeArrayDType* asamep = static_cast<const AstNodeArrayDType*>(samep);
+	return (msb()==asamep->msb()
+		&& subDTypep()==asamep->subDTypep()
+		&& rangenp()->sameTree(asamep->rangenp())); }  // HashedDT doesn't recurse, so need to check children
+    virtual bool similarDType(AstNodeDType* samep) const {
+	const AstNodeArrayDType* asamep = static_cast<const AstNodeArrayDType*>(samep);
+	return (asamep
+		&& type() == samep->type()
+		&& msb() == asamep->msb()
+		&& rangenp()->sameTree(asamep->rangenp())
+		&& subDTypep()->skipRefp()->similarDType(asamep->subDTypep()->skipRefp()));
+    }
    virtual V3Hash sameHash() const { return V3Hash(V3Hash(m_refDTypep),V3Hash(msb()),V3Hash(lsb())); }
    AstNodeDType* getChildDTypep() const { return childDTypep(); }
    AstNodeDType* childDTypep() const { return op1p()->castNodeDType(); } // op1 = Range of variable
    void	childDTypep(AstNodeDType* nodep) { setOp1p(nodep); }
-    AstNodeDType* subDTypep() const { return m_refDTypep ? m_refDTypep : childDTypep(); }
+    virtual AstNodeDType* subDTypep() const { return m_refDTypep ? m_refDTypep : childDTypep(); }
    void refDTypep(AstNodeDType* nodep) { m_refDTypep = nodep; }
    virtual AstNodeDType* virtRefDTypep() const { return m_refDTypep; }
    virtual void virtRefDTypep(AstNodeDType* nodep) { refDTypep(nodep); }
@@ -1764,9 +1841,9 @@ public:
    AstNodeSel(FileLine* fl, AstNode* fromp, AstNode* bitp)
 	:AstNodeBiop(fl, fromp, bitp) {}
    ASTNODE_BASE_FUNCS(NodeSel)
-    AstNode* fromp() const { return op1p()->castNode(); }	// op1 = Extracting what (NULL=TBD during parsing)
+    AstNode* fromp() const { return op1p(); }	// op1 = Extracting what (NULL=TBD during parsing)
    void fromp(AstNode* nodep) { setOp1p(nodep); }
-    AstNode* bitp() const { return op2p()->castNode(); }	// op2 = Msb selection expression
+    AstNode* bitp() const { return op2p(); }	// op2 = Msb selection expression
    void bitp(AstNode* nodep) { setOp2p(nodep); }
    int	     bitConst()	const;
    virtual bool hasDType() const { return true; }
@@ -1818,11 +1895,11 @@ public:
    string cname() const { return m_cname; }
    void cname(const string& cname) { m_cname = cname; }
    // op1 = Output variable (functions only, NULL for tasks)
-    AstNode*	fvarp() 	const { return op1p()->castNode(); }
+    AstNode*	fvarp() 	const { return op1p(); }
    void 	addFvarp(AstNode* nodep) { addNOp1p(nodep); }
    bool	isFunction() const { return fvarp()!=NULL; }
    // op3 = Statements/Ports/Vars
-    AstNode*	stmtsp() 	const { return op3p()->castNode(); }	// op3 = List of statements
+    AstNode*	stmtsp() 	const { return op3p(); }	// op3 = List of statements
    void	addStmtsp(AstNode* nodep) { addNOp3p(nodep); }
    // op4 = scope name
    AstScopeName* scopeNamep() const { return op4p()->castScopeName(); }
@@ -1867,7 +1944,7 @@ public:
    ASTNODE_BASE_FUNCS(NodeFTaskRef)
    virtual const char* broken() const { BROKEN_RTN(m_taskp && !m_taskp->brokeExists()); return NULL; }
    virtual void cloneRelink() { if (m_taskp && m_taskp->clonep()) {
-	m_taskp = m_taskp->clonep()->castNodeFTask();
+	m_taskp = m_taskp->clonep();
    }}
    virtual void dump(ostream& str=cout);
    virtual string name()	const { return m_name; }		// * = Var name
@@ -1885,7 +1962,7 @@ public:
    // op1 = namep
    AstNode*	namep()		const { return op1p(); }
    // op2 = Pin interconnection list
-    AstNode*	pinsp() 	const { return op2p()->castNode(); }
+    AstNode*	pinsp() 	const { return op2p(); }
    void addPinsp(AstNode* nodep) { addOp2p(nodep); }
    // op3 = scope tracking
    AstScopeName* scopeNamep() const { return op3p()->castScopeName(); }
@@ -1904,6 +1981,8 @@ private:
    bool	m_inLibrary:1;	// From a library, no error if not used, never top level
    bool	m_dead:1;	// LinkDot believes is dead; will remove in Dead visitors
    bool	m_internal:1;	// Internally created
+    bool	m_recursive:1;	// Recursive module
+    bool	m_recursiveClone:1;  // If recursive, what module it clones, otherwise NULL
    int		m_level;	// 1=top module, 2=cell off top module, ...
    int		m_varNum;	// Incrementing variable number
    int		m_typeNum;	// Incrementing implicit type number
@@ -1911,13 +1990,14 @@ public:
    AstNodeModule(FileLine* fl, const string& name)
 	: AstNode (fl)
 	,m_name(name), m_origName(name)
-	,m_modPublic(false), m_modTrace(false), m_inLibrary(false), m_dead(false), m_internal(false)
+	,m_modPublic(false), m_modTrace(false), m_inLibrary(false), m_dead(false)
+	,m_internal(false), m_recursive(false), m_recursiveClone(false)
 	,m_level(0), m_varNum(0), m_typeNum(0) { }
    ASTNODE_BASE_FUNCS(NodeModule)
    virtual void dump(ostream& str);
    virtual bool maybePointedTo() const { return true; }
    virtual string name()	const { return m_name; }
-    AstNode*	stmtsp() 	const { return op2p()->castNode(); }	// op2 = List of statements
+    AstNode*	stmtsp() 	const { return op2p(); }	// op2 = List of statements
    AstActive*  activesp()	const { return op3p()->castActive(); }	// op3 = List of i/sblocks
    // METHODS
    void addInlinesp(AstNode* nodep) { addOp1p(nodep); }
@@ -1941,6 +2021,10 @@ public:
    bool dead() const	 	{ return m_dead; }
    void internal(bool flag) 	{ m_internal = flag; }
    bool internal() const	{ return m_internal; }
+    void recursive(bool flag) { m_recursive = flag; }
+    bool recursive() const { return m_recursive; }
+    void recursiveClone(bool flag) { m_recursiveClone = flag; }
+    bool recursiveClone() const { return m_recursiveClone; }
 };

 //######################################################################
@@ -1967,8 +2051,8 @@ inline bool AstNode::isNeqZero()  { return (this->castConst() && this->castConst
 inline bool AstNode::isOne()      { return (this->castConst() && this->castConst()->num().isEqOne()); }
 inline bool AstNode::isAllOnes()  { return (this->castConst() && this->castConst()->isEqAllOnes()); }
 inline bool AstNode::isAllOnesV() { return (this->castConst() && this->castConst()->isEqAllOnesV()); }
-inline bool AstNode::sameTree(AstNode* node2p) { return sameTreeIter(node2p, true, false); }
-inline bool AstNode::sameGateTree(AstNode* node2p) { return sameTreeIter(node2p, true, true); }
+inline bool AstNode::sameTree(AstNode* node2p) { return sameTreeIter(this, node2p, true, false); }
+inline bool AstNode::sameGateTree(AstNode* node2p) { return sameTreeIter(this, node2p, true, true); }

 inline void AstNodeVarRef::init() { if (m_varp) dtypep(m_varp->dtypep()); }

@@ -1979,8 +2063,8 @@ inline int AstNodeArrayDType::elementsConst() const { return rangep()->elementsC
 inline VNumRange AstNodeArrayDType::declRange() const { return VNumRange(msb(), lsb(), rangep()->littleEndian()); }

 inline void AstIfaceRefDType::cloneRelink() {
-    if (m_cellp && m_cellp->clonep()) m_cellp = m_cellp->clonep()->castCell();
-    if (m_ifacep && m_ifacep->clonep()) m_ifacep = m_ifacep->clonep()->castIface();
-    if (m_modportp && m_modportp->clonep()) m_modportp = m_modportp->clonep()->castModport(); }
+    if (m_cellp && m_cellp->clonep()) m_cellp = m_cellp->clonep();
+    if (m_ifacep && m_ifacep->clonep()) m_ifacep = m_ifacep->clonep();
+    if (m_modportp && m_modportp->clonep()) m_modportp = m_modportp->clonep(); }

 #endif // Guard
@@ -6,7 +6,7 @@
 //
 //*************************************************************************
 //
-// Copyright 2003-2015 by Wilson Snyder.  This program is free software; you can
+// Copyright 2003-2017 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.
@@ -6,7 +6,7 @@
 //
 //*************************************************************************
 //
-// Copyright 2003-2015 by Wilson Snyder.  This program is free software; you can
+// Copyright 2003-2017 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.
@@ -26,6 +26,7 @@
 #include <iomanip>
 #include <vector>
 #include <algorithm>
+#include VL_INCLUDE_UNORDERED_SET

 #include "V3Ast.h"
 #include "V3File.h"
@@ -53,7 +54,7 @@ const char* AstNodeVarRef::broken() const {
 }

 void AstNodeVarRef::cloneRelink() {
-    if (m_varp && m_varp->clonep()) { m_varp = m_varp->clonep()->castVar(); }
+    if (m_varp && m_varp->clonep()) { m_varp = m_varp->clonep(); }
 }

 int AstNodeSel::bitConst() const {
@@ -69,7 +70,7 @@ void AstNodeClassDType::repairMemberCache() {
 }

 const char* AstNodeClassDType::broken() const {
-    set<AstMemberDType*> exists;
+    vl_unordered_set<AstMemberDType*> exists;
    for (AstMemberDType* itemp = membersp(); itemp; itemp=itemp->nextp()->castMemberDType()) {
 	exists.insert(itemp);
    }
@@ -140,6 +141,13 @@ AstNodeBiop* AstLte::newTyped(FileLine* fl, AstNode* lhsp, AstNode* rhsp) {
    }
 }

+AstNodeBiop* AstEqWild::newTyped(FileLine* fl, AstNode* lhsp, AstNode* rhsp) {
+    if (lhsp->isDouble() && rhsp->isDouble()) {
+	return new AstEqD(fl, lhsp, rhsp);
+    } else {
+	return new AstEqWild(fl, lhsp, rhsp);
+    }
+}

 bool AstVar::isSigPublic() const {
    return (m_sigPublic || (v3Global.opt.allPublic() && !isTemp() && !isGenVar()));
@@ -195,6 +203,8 @@ string AstVar::verilogKwd() const {
 	return "tri";
    } else if (varType()==AstVarType::WIRE) {
 	return "wire";
+    } else if (varType()==AstVarType::WREAL) {
+	return "wreal";
    } else {
 	return dtypep()->name();
    }
@@ -217,7 +227,7 @@ string AstVar::vlArgType(bool named, bool forReturn, bool forFunc) const {
 	arg += "float";
    } else if (strtype) {
 	if (isInOnly()) arg += "const ";
-	arg += "string";
+	arg += "std::string";
    } else if (widthMin() <= 8) {
 	arg += "CData";
    } else if (widthMin() <= 16) {
@@ -386,6 +396,7 @@ AstNodeDType* AstNodeDType::dtypeDimensionp(int dimension) {
    // TODO this function should be removed in favor of recursing the dtype(),
    // as that allows for more complicated data types.
    int dim = 0;
+    UDEBUGONLY(UASSERT(dynamic_cast<AstNode*>(this),"this should not be NULL"););
    for (AstNodeDType* dtypep=this; dtypep; ) {
 	dtypep = dtypep->skipRefp();  // Skip AstRefDType/AstTypedef, or return same node
 	if (AstNodeArrayDType* adtypep = dtypep->castNodeArrayDType()) {
@@ -420,6 +431,7 @@ AstNodeDType* AstNodeDType::dtypeDimensionp(int dimension) {

 uint32_t AstNodeDType::arrayUnpackedElements() {
    uint32_t entries=1;
+    UDEBUGONLY(UASSERT(dynamic_cast<AstNode*>(this),"this should not be NULL"););
    for (AstNodeDType* dtypep=this; dtypep; ) {
 	dtypep = dtypep->skipRefp();  // Skip AstRefDType/AstTypedef, or return same node
 	if (AstUnpackArrayDType* adtypep = dtypep->castUnpackArrayDType()) {
@@ -438,6 +450,7 @@ pair<uint32_t,uint32_t> AstNodeDType::dimensions(bool includeBasic) {
    // How many array dimensions (packed,unpacked) does this Var have?
    uint32_t packed = 0;
    uint32_t unpacked = 0;
+    UDEBUGONLY(UASSERT(dynamic_cast<AstNode*>(this),"this should not be NULL"););
    for (AstNodeDType* dtypep=this; dtypep; ) {
 	dtypep = dtypep->skipRefp();  // Skip AstRefDType/AstTypedef, or return same node
 	if (AstNodeArrayDType* adtypep = dtypep->castNodeArrayDType()) {
@@ -492,9 +505,9 @@ const char* AstScope::broken() const {
 }

 void AstScope::cloneRelink() {
-    if (m_aboveScopep && m_aboveScopep->clonep()) m_aboveScopep->clonep()->castScope();
-    if (m_aboveCellp && m_aboveCellp->clonep()) m_aboveCellp->clonep()->castCell();
-    if (m_modp && ((AstNode*)m_modp)->clonep()) ((AstNode*)m_modp)->clonep()->castNodeModule();
+    if (m_aboveScopep && m_aboveScopep->clonep()) m_aboveScopep->clonep();
+    if (m_aboveCellp && m_aboveCellp->clonep()) m_aboveCellp->clonep();
+    if (m_modp && ((AstNode*)m_modp)->clonep()) ((AstNode*)m_modp)->clonep();
 }

 string AstScope::nameDotless() const {
@@ -536,28 +549,28 @@ string AstScopeName::scopeNameFormatter(AstText* scopeTextp) const {
    return out;
 }

-bool AstSenTree::hasClocked() {
+bool AstSenTree::hasClocked() const {
    if (!sensesp()) this->v3fatalSrc("SENTREE without any SENITEMs under it");
    for (AstNodeSenItem* senp = sensesp(); senp; senp=senp->nextp()->castNodeSenItem()) {
 	if (senp->isClocked()) return true;
    }
    return false;
 }
-bool AstSenTree::hasSettle() {
+bool AstSenTree::hasSettle() const {
    if (!sensesp()) this->v3fatalSrc("SENTREE without any SENITEMs under it");
    for (AstNodeSenItem* senp = sensesp(); senp; senp=senp->nextp()->castNodeSenItem()) {
 	if (senp->isSettle()) return true;
    }
    return false;
 }
-bool AstSenTree::hasInitial() {
+bool AstSenTree::hasInitial() const {
    if (!sensesp()) this->v3fatalSrc("SENTREE without any SENITEMs under it");
    for (AstNodeSenItem* senp = sensesp(); senp; senp=senp->nextp()->castNodeSenItem()) {
 	if (senp->isInitial()) return true;
    }
    return false;
 }
-bool AstSenTree::hasCombo() {
+bool AstSenTree::hasCombo() const {
    if (!sensesp()) this->v3fatalSrc("SENTREE without any SENITEMs under it");
    for (AstNodeSenItem* senp = sensesp(); senp; senp=senp->nextp()->castNodeSenItem()) {
 	if (senp->isCombo()) return true;
@@ -751,10 +764,6 @@ void AstAlways::dump(ostream& str) {
    if (keyword() != VAlwaysKwd::ALWAYS) str<<" ["<<keyword().ascii()<<"]";
 }

-void AstArraySel::dump(ostream& str) {
-    this->AstNode::dump(str);
-    str<<" [start:"<<start()<<"] [length:"<<length()<<"]";
-}
 void AstAttrOf::dump(ostream& str) {
    this->AstNode::dump(str);
    str<<" ["<<attrType().ascii()<<"]";
@@ -770,6 +779,7 @@ void AstCCast::dump(ostream& str) {
 }
 void AstCell::dump(ostream& str) {
    this->AstNode::dump(str);
+    if (recursive()) str<<" [RECURSIVE]";
    if (modp()) { str<<" -> "; modp()->dump(str); }
    else { str<<" ->UNLINKED:"<<modName(); }
 }
@@ -878,6 +888,12 @@ void AstNodeModule::dump(ostream& str) {
    if (modPublic()) str<<" [P]";
    if (inLibrary()) str<<" [LIB]";
    if (dead()) str<<" [DEAD]";
+    if (recursiveClone()) str<<" [RECURSIVE-CLONE]";
+    else if (recursive()) str<<" [RECURSIVE]";
+}
+void AstPackageExport::dump(ostream& str) {
+    this->AstNode::dump(str);
+    str<<" -> "<<packagep();
 }
 void AstPackageImport::dump(ostream& str) {
    this->AstNode::dump(str);
@@ -890,6 +906,12 @@ void AstSel::dump(ostream& str) {
 	if (declElWidth()!=1) str<<"/"<<declElWidth();
    }
 }
+void AstSliceSel::dump(ostream& str) {
+    this->AstNode::dump(str);
+    if (declRange().ranged()) {
+        str<<" decl"<<declRange();
+    }
+}
 void AstTypeTable::dump(ostream& str) {
    this->AstNode::dump(str);
    for (int i=0; i<(int)(AstBasicDTypeKwd::_ENUM_MAX); ++i) {
@@ -974,6 +996,7 @@ void AstVar::dump(ostream& str) {
    if (attrFileDescr()) str<<" [aFD]";
    if (isFuncReturn()) str<<" [FUNCRTN]";
    else if (isFuncLocal()) str<<" [FUNC]";
+    if (!attrClocker().unknown()) str<<" ["<<attrClocker().ascii()<<"] ";
    str<<" "<<varType();
 }
 void AstSenTree::dump(ostream& str) {
@@ -6,7 +6,7 @@
 //
 //*************************************************************************
 //
-// Copyright 2003-2015 by Wilson Snyder.  This program is free software; you can
+// Copyright 2003-2017 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.
@@ -56,7 +56,7 @@ public:
 	m_anyFuncInBegin = false;
    }
    ~BeginState() {}
-    void userMarkChanged(AstNodeFTask* nodep) {
+    void userMarkChanged(AstNode* nodep) {
 	nodep->user1(true);
 	m_anyFuncInBegin = true;
    }
@@ -84,13 +84,13 @@ private:
    }

    // VISITORS
-    virtual void visit(AstNodeModule* nodep, AstNUser*) {
+    virtual void visit(AstNodeModule* nodep) {
 	m_modp = nodep;
 	m_repeatNum = 0;
 	nodep->iterateChildren(*this);
 	m_modp = NULL;
    }
-    virtual void visit(AstNodeFTask* nodep, AstNUser*) {
+    virtual void visit(AstNodeFTask* nodep) {
 	UINFO(8,"  "<<nodep<<endl);
 	// Rename it
 	if (m_unnamedScope != "") {
@@ -113,7 +113,7 @@ private:
 	m_namedScope = oldScope;
 	m_unnamedScope = oldUnnamed;
    }
-    virtual void visit(AstBegin* nodep, AstNUser*) {
+    virtual void visit(AstBegin* nodep) {
 	// Begin blocks were only useful in variable creation, change names and delete
 	UINFO(8,"  "<<nodep<<endl);
 	string oldScope = m_namedScope;
@@ -162,19 +162,21 @@ private:
 	}
 	pushDeletep(nodep); VL_DANGLING(nodep);
    }
-    virtual void visit(AstVar* nodep, AstNUser*) {
+    virtual void visit(AstVar* nodep) {
 	if (m_unnamedScope != "") {
 	    // Rename it
 	    nodep->name(m_unnamedScope+"__DOT__"+nodep->name());
+	    m_statep->userMarkChanged(nodep);
 	    // Move to module
 	    nodep->unlinkFrBack();
 	    if (m_ftaskp) m_ftaskp->addStmtsp(nodep);   // Begins under funcs just move into the func
 	    else m_modp->addStmtp(nodep);
 	}
    }
-    virtual void visit(AstCell* nodep, AstNUser*) {
+    virtual void visit(AstCell* nodep) {
 	UINFO(8,"   CELL "<<nodep<<endl);
 	if (m_namedScope != "") {
+	    m_statep->userMarkChanged(nodep);
 	    // Rename it
 	    nodep->name(m_namedScope+"__DOT__"+nodep->name());
 	    UINFO(8,"     rename to "<<nodep->name()<<endl);
@@ -182,8 +184,16 @@ private:
 	    nodep->unlinkFrBack();
 	    m_modp->addStmtp(nodep);
 	}
+	nodep->iterateChildren(*this);
    }
-    virtual void visit(AstScopeName* nodep, AstNUser*) {
+    virtual void visit(AstVarXRef* nodep) {
+	UINFO(9, "   VARXREF "<<nodep<<endl);
+	if (m_namedScope != "" && nodep->inlinedDots() == "") {
+	    nodep->inlinedDots(m_namedScope);
+	    UINFO(9, "    rescope to "<<nodep<<endl);
+	}
+    }
+    virtual void visit(AstScopeName* nodep) {
 	// If there's a %m in the display text, we add a special node that will contain the name()
 	// Similar code in V3Inline
 	if (nodep->user1SetOnce()) return;  // Don't double-add text's
@@ -196,13 +206,13 @@ private:
 	}
 	nodep->iterateChildren(*this);
    }
-    virtual void visit(AstCoverDecl* nodep, AstNUser*) {
+    virtual void visit(AstCoverDecl* nodep) {
 	// Don't need to fix path in coverage statements, they're not under
 	// any BEGINs, but V3Coverage adds them all under the module itself.
 	nodep->iterateChildren(*this);
    }
    // VISITORS - LINT CHECK
-    virtual void visit(AstIf* nodep, AstNUser*) { // Note not AstNodeIf; other types don't get covered
+    virtual void visit(AstIf* nodep) { // Note not AstNodeIf; other types don't get covered
 	// Check IFDEPTH warning - could be in other transform files if desire
 	int prevIfDepth = m_ifDepth;
 	if (m_ifDepth == -1 || v3Global.opt.ifDepth()<1) { // Turned off
@@ -215,8 +225,8 @@ private:
 	}
 	nodep->iterateChildren(*this);
 	m_ifDepth = prevIfDepth;
-     }
-    virtual void visit(AstNode* nodep, AstNUser*) {
+    }
+    virtual void visit(AstNode* nodep) {
 	nodep->iterateChildren(*this);
    }
 public:
@@ -242,15 +252,30 @@ private:
    //   AstNodeFTask::user1p		// Node replaced, rename it

    // VISITORS
-    virtual void visit(AstNodeFTaskRef* nodep, AstNUser*) {
+    virtual void visit(AstNodeFTaskRef* nodep) {
 	if (nodep->taskp()->user1()) { // It was converted
 	    UINFO(9, "    relinkFTask "<<nodep<<endl);
 	    nodep->name(nodep->taskp()->name());
 	}
 	nodep->iterateChildren(*this);
    }
+    virtual void visit(AstVarRef* nodep) {
+	if (nodep->varp()->user1()) { // It was converted
+	    UINFO(9, "    relinVarRef "<<nodep<<endl);
+	    nodep->name(nodep->varp()->name());
+	}
+	nodep->iterateChildren(*this);
+    }
+    virtual void visit(AstIfaceRefDType* nodep) {
+	// May have changed cell names
+	// TypeTable is always after all modules, so names are stable
+	UINFO(8,"   IFACEREFDTYPE "<<nodep<<endl);
+	if (nodep->cellp()) nodep->cellName(nodep->cellp()->name());
+	UINFO(8,"       rename to "<<nodep<<endl);
+	nodep->iterateChildren(*this);
+    }
    //--------------------
-    virtual void visit(AstNode* nodep, AstNUser*) {
+    virtual void visit(AstNode* nodep) {
 	nodep->iterateChildren(*this);
    }
 public:
@@ -271,5 +296,5 @@ void V3Begin::debeginAll(AstNetlist* nodep) {
    if (state.anyFuncInBegin()) {
 	BeginRelinkVisitor brvisitor (nodep,&state);
    }
-    V3Global::dumpCheckGlobalTree("begin.tree", 0, v3Global.opt.dumpTreeLevel(__FILE__) >= 3);
+    V3Global::dumpCheckGlobalTree("begin", 0, v3Global.opt.dumpTreeLevel(__FILE__) >= 3);
 }
@@ -6,7 +6,7 @@
 //
 //*************************************************************************
 //
-// Copyright 2003-2015 by Wilson Snyder.  This program is free software; you can
+// Copyright 2003-2017 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.
@@ -6,7 +6,7 @@
 //
 //*************************************************************************
 //
-// Copyright 2003-2015 by Wilson Snyder.  This program is free software; you can
+// Copyright 2003-2017 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.
@@ -75,7 +75,7 @@ private:
    }

    // VISITORS
-    virtual void visit(AstNodeIf* nodep, AstNUser*) {
+    virtual void visit(AstNodeIf* nodep) {
 	UINFO(4," IF: "<<nodep<<endl);
 	int lastLikely = m_likely;
 	int lastUnlikely = m_unlikely;
@@ -101,17 +101,17 @@ private:
 	m_likely = lastLikely;
 	m_unlikely = lastUnlikely;
    }
-    virtual void visit(AstCCall* nodep, AstNUser*) {
+    virtual void visit(AstCCall* nodep) {
 	checkUnlikely(nodep);
 	nodep->funcp()->user1Inc();
 	nodep->iterateChildren(*this);
    }
-    virtual void visit(AstCFunc* nodep, AstNUser*) {
+    virtual void visit(AstCFunc* nodep) {
 	checkUnlikely(nodep);
 	m_cfuncsp.push_back(nodep);
 	nodep->iterateChildren(*this);
    }
-    virtual void visit(AstNode* nodep, AstNUser*) {
+    virtual void visit(AstNode* nodep) {
 	checkUnlikely(nodep);
 	nodep->iterateChildren(*this);
    }
@@ -6,7 +6,7 @@
 //
 //*************************************************************************
 //
-// Copyright 2003-2015 by Wilson Snyder.  This program is free software; you can
+// Copyright 2003-2017 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.
@@ -29,7 +29,7 @@

 class V3Branch {
 public:
-    // CREATORS
+    // CONSTRUCTORS
    static void branchAll(AstNetlist* rootp);
 };

@@ -6,7 +6,7 @@
 //
 //*************************************************************************
 //
-// Copyright 2003-2015 by Wilson Snyder.  This program is free software; you can
+// Copyright 2003-2017 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.
@@ -31,7 +31,7 @@
 #include <cstdarg>
 #include <unistd.h>
 #include <algorithm>
-#include <map>
+#include VL_INCLUDE_UNORDERED_MAP

 #include "V3Global.h"
 #include "V3Broken.h"
@@ -47,7 +47,7 @@ class BrokenTable : public AstNVisitor {
 private:
    // MEMBERS
    //   For each node, we keep if it exists or not.
-    typedef map<const AstNode*,int> NodeMap;
+    typedef vl_unordered_map<const AstNode*,int> NodeMap;  // Performance matters (when --debug)
    static NodeMap s_nodes;	// Set of all nodes that exist
    // BITMASK
    enum { FLAG_ALLOCATED	= 0x01 };	// new() and not delete()ed
@@ -62,16 +62,20 @@ public:
 	if (debug()>=9) cout<<"-nodeDel:  "<<(void*)(nodep)<<endl;
 	NodeMap::iterator iter = s_nodes.find(nodep);
 	if (iter==s_nodes.end() || !(iter->second & FLAG_ALLOCATED)) {
-	    ((AstNode*)(nodep))->v3fatalSrc("Deleting AstNode object that was never tracked or already deleted\n");
+	    ((AstNode*)(nodep))->v3fatalSrc("Deleting AstNode object that was never tracked or already deleted");
 	}
 	if (iter!=s_nodes.end()) s_nodes.erase(iter);
    }
+#if defined(__GNUC__) && __GNUC__ == 4 && __GNUC_MINOR__ == 4
+    // GCC 4.4.* compiler warning bug, https://gcc.gnu.org/bugzilla/show_bug.cgi?id=39390
+# pragma GCC diagnostic ignored "-Wstrict-aliasing"
+#endif
    static void addNewed(const AstNode* nodep) {
 	// Called by operator new on any node - only if VL_LEAK_CHECKS
 	if (debug()>=9) cout<<"-nodeNew:  "<<(void*)(nodep)<<endl;
 	NodeMap::iterator iter = s_nodes.find(nodep);
 	if (iter!=s_nodes.end() || (iter->second & FLAG_ALLOCATED)) {
-	    ((AstNode*)(nodep))->v3fatalSrc("Newing AstNode object that is already allocated\n");
+	    nodep->v3fatalSrc("Newing AstNode object that is already allocated");
 	}
 	if (iter == s_nodes.end()) {
 	    int flags = FLAG_ALLOCATED;  // This int needed to appease GCC 4.1.2
@@ -94,16 +98,16 @@ public:
 	NodeMap::iterator iter = s_nodes.find(nodep);
 	if (iter == s_nodes.end()) {
 #ifdef VL_LEAK_CHECKS
-	    nodep->v3fatalSrc("AstNode is in tree, but not allocated\n");
+	    nodep->v3fatalSrc("AstNode is in tree, but not allocated");
 #endif
 	} else {
 	    if (!(iter->second & FLAG_ALLOCATED)) {
 #ifdef VL_LEAK_CHECKS
-		nodep->v3fatalSrc("AstNode is in tree, but not allocated\n");
+		nodep->v3fatalSrc("AstNode is in tree, but not allocated");
 #endif
 	    }
 	    if (iter->second & FLAG_IN_TREE) {
-		nodep->v3fatalSrc("AstNode is already in tree at another location\n");
+		nodep->v3fatalSrc("AstNode is already in tree at another location");
 	    }
 	}
 	int or_flags = FLAG_IN_TREE | (linkable?FLAG_LINKABLE:0);
@@ -192,7 +196,7 @@ private:
 	nodep->iterateChildrenConst(*this);
    }
    // VISITORS
-    virtual void visit(AstNode* nodep, AstNUser*) {
+    virtual void visit(AstNode* nodep) {
 	processAndIterate(nodep);
    }
 public:
@@ -236,7 +240,16 @@ private:
 	nodep->iterateChildrenConst(*this);
 	BrokenTable::setUnder(nodep,false);
    }
-    virtual void visit(AstNode* nodep, AstNUser*) {
+    virtual void visit(AstNodeAssign* nodep) {
+	processAndIterate(nodep);
+	if (v3Global.assertDTypesResolved()
+	    && nodep->brokeLhsMustBeLvalue()
+	    && nodep->lhsp()->castNodeVarRef()
+	    && !nodep->lhsp()->castNodeVarRef()->lvalue()) {
+	    nodep->v3fatalSrc("Assignment LHS is not an lvalue");
+	}
+    }
+    virtual void visit(AstNode* nodep) {
 	processAndIterate(nodep);
    }
 public:
@@ -6,7 +6,7 @@
 //
 //*************************************************************************
 //
-// Copyright 2003-2015 by Wilson Snyder.  This program is free software; you can
+// Copyright 2003-2017 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.
@@ -0,0 +1,170 @@
+// -*- mode: C++; c-file-style: "cc-mode" -*-
+//*************************************************************************
+// DESCRIPTION: Verilator: Generate C language constructors and AstCReset nodes.
+//
+// Code available from: http://www.veripool.org/verilator
+//
+//*************************************************************************
+//
+// Copyright 2003-2017 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.
+//
+// Verilator is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+//*************************************************************************
+// V3CCtors's Transformations:
+//	Iterates over all modules and
+// 	for all AstVar, create a creates a AstCReset node in an _ctor_var_reset AstCFunc.
+//	for all AstCoverDecl, move the declaration into a _configure_coverage AstCFunc.
+//	For each variable that needs reset, add a AstCReset node.
+//
+//	For primary inputs, add _eval_debug_assertions.
+//
+//	This transformation honors outputSplitCFuncs.
+//*************************************************************************
+#include "config_build.h"
+#include "verilatedos.h"
+#include <cstdio>
+#include <cstdarg>
+#include <unistd.h>
+#include <cmath>
+#include <map>
+#include <vector>
+#include <algorithm>
+
+#include "V3Global.h"
+#include "V3EmitCBase.h"
+#include "V3CCtors.h"
+
+class V3CCtorsVisitor {
+private:
+    string 		m_basename;
+    string 		m_argsp;
+    string 		m_callargsp;
+    AstNodeModule*	m_modp;		// Current module
+    AstCFunc*		m_tlFuncp;	// Top level function being built
+    AstCFunc*		m_funcp;	// Current function
+    int			m_numStmts;	// Number of statements output
+    int			m_funcNum;	// Function number being built
+
+public:
+    void add(AstNode* nodep) {
+	if (v3Global.opt.outputSplitCFuncs()
+	    && v3Global.opt.outputSplitCFuncs() < m_numStmts) {
+	    m_funcp = NULL;
+	}
+	if (!m_funcp) {
+	    m_funcp = new AstCFunc(m_modp->fileline(), m_basename + "_" + cvtToStr(++m_funcNum), NULL, "void");
+	    m_funcp->isStatic(false);
+	    m_funcp->declPrivate(true);
+	    m_funcp->slow(true);
+	    m_funcp->argTypes(m_argsp);
+	    m_modp->addStmtp(m_funcp);
+
+	    // Add a top call to it
+	    AstCCall* callp = new AstCCall(m_modp->fileline(), m_funcp);
+	    callp->argTypes(m_callargsp);
+
+	    m_tlFuncp->addStmtsp(callp);
+	    m_numStmts = 0;
+	}
+	m_funcp->addStmtsp(nodep);
+	m_numStmts += 1;
+    }
+
+    V3CCtorsVisitor(AstNodeModule* nodep, string basename, string argsp="", string callargsp="",
+		    const string& stmt="") {
+	m_basename = basename;
+	m_argsp = argsp;
+	m_callargsp = callargsp;
+	m_modp = nodep;
+	m_numStmts = 0;
+	m_funcNum = 0;
+	m_tlFuncp = new AstCFunc(nodep->fileline(), basename, NULL, "void");
+	m_tlFuncp->declPrivate(true);
+	m_tlFuncp->isStatic(false);
+	m_tlFuncp->slow(true);
+	m_tlFuncp->argTypes(m_argsp);
+	if (stmt != "") {
+	    m_tlFuncp->addStmtsp(new AstCStmt(nodep->fileline(), stmt));
+	}
+	m_funcp = m_tlFuncp;
+	m_modp->addStmtp(m_tlFuncp);
+    }
+    ~V3CCtorsVisitor() {}
+private:
+    VL_UNCOPYABLE(V3CCtorsVisitor);
+};
+
+//######################################################################
+
+void V3CCtors::evalAsserts() {
+    AstNodeModule* modp = v3Global.rootp()->modulesp();  // Top module
+    AstCFunc* funcp = new AstCFunc(modp->fileline(), "_eval_debug_assertions", NULL, "void");
+    funcp->declPrivate(true);
+    funcp->isStatic(false);
+    funcp->slow(false);
+    funcp->ifdef("VL_DEBUG");
+    modp->addStmtp(funcp);
+    for (AstNode* np = modp->stmtsp(); np; np = np->nextp()) {
+	if (AstVar* varp = np->castVar()) {
+	    if (varp->isPrimaryIn() && !varp->isSc()) {
+		if (AstBasicDType* basicp = varp->dtypeSkipRefp()->castBasicDType()) {
+		    int storedWidth = basicp->widthAlignBytes() * 8;
+		    int lastWordWidth = varp->width() % storedWidth;
+		    if (lastWordWidth != 0) {
+			// if (signal & CONST(upper_non_clean_mask)) { fail; }
+			AstNode* newp = new AstVarRef(varp->fileline(), varp, false);
+			if (varp->isWide()) {
+			    newp = new AstWordSel(varp->fileline(), newp,
+						  new AstConst(varp->fileline(), varp->widthWords()-1));
+			}
+			uint64_t value = VL_MASK_Q(storedWidth) & ~VL_MASK_Q(lastWordWidth);
+			V3Number num (varp->fileline(), storedWidth, value);
+			newp = new AstAnd(varp->fileline(), newp,
+					  new AstConst(varp->fileline(), num));
+			AstNodeIf* ifp = new AstIf(varp->fileline(), newp,
+						   new AstCStmt(varp->fileline(), "Verilated::overWidthError(\""+varp->prettyName()+"\");"));
+			ifp->branchPred(AstBranchPred::BP_UNLIKELY);
+			newp = ifp;
+			funcp->addStmtsp(newp);
+		    }
+		}
+	    }
+	}
+    }
+}
+
+void V3CCtors::cctorsAll() {
+    UINFO(2,__FUNCTION__<<": "<<endl);
+    evalAsserts();
+    for (AstNodeModule* modp = v3Global.rootp()->modulesp(); modp; modp=modp->nextp()->castNodeModule()) {
+        // Process each module in turn
+        {
+            V3CCtorsVisitor var_reset (modp, "_ctor_var_reset");
+            for (AstNode* np = modp->stmtsp(); np; np = np->nextp()) {
+                if (AstVar* varp = np->castVar()) {
+                    var_reset.add(new AstCReset(varp->fileline(), new AstVarRef(varp->fileline(), varp, true)));
+                }
+            }
+        }
+        if (v3Global.opt.coverage()) {
+            V3CCtorsVisitor configure_coverage
+                (modp, "_configure_coverage", EmitCBaseVisitor::symClassVar()+ ", bool first", "vlSymsp, first",
+                 "if (0 && vlSymsp && first) {} // Prevent unused\n");
+            for (AstNode* np = modp->stmtsp(); np; np = np->nextp()) {
+                if (AstCoverDecl* coverp = np->castCoverDecl()) {
+                    AstNode* backp = coverp->backp();
+                    coverp->unlinkFrBack();
+                    configure_coverage.add(coverp);
+                    np = backp;
+                }
+            }
+        }
+    }
+}
@@ -0,0 +1,38 @@
+// -*- mode: C++; c-file-style: "cc-mode" -*-
+//*************************************************************************
+// DESCRIPTION: Verilator: Emit CFunc's for class construction and configuration
+//
+// Code available from: http://www.veripool.org/verilator
+//
+//*************************************************************************
+//
+// Copyright 2003-2017 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.
+//
+// Verilator is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+//*************************************************************************
+
+#ifndef _V3CCTORS_H_
+#define _V3CCTORS_H_ 1
+#include "config_build.h"
+#include "verilatedos.h"
+#include "V3Error.h"
+#include "V3Ast.h"
+
+//============================================================================
+
+class V3CCtors {
+public:
+    static void cctorsAll();
+private:
+    static void evalAsserts();
+};
+
+
+#endif // Guard
@@ -6,7 +6,7 @@
 //
 //*************************************************************************
 //
-// Copyright 2003-2015 by Wilson Snyder.  This program is free software; you can
+// Copyright 2003-2017 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.
@@ -65,7 +65,7 @@ private:
 	return level;
    }

-    virtual void visit(AstNodeCase* nodep, AstNUser*) {
+    virtual void visit(AstNodeCase* nodep) {
 	if (nodep->castCase() && nodep->castCase()->casex()) {
 	    nodep->v3warn(CASEX,"Suggest casez (with ?'s) in place of casex (with X's)");
 	}
@@ -90,7 +90,7 @@ private:
 	    m_caseExprp = NULL;
 	}
    }
-    virtual void visit(AstConst* nodep, AstNUser*) {
+    virtual void visit(AstConst* nodep) {
 	// See also neverItem
 	if (m_caseExprp && nodep->num().isFourState()) {
 	    if (m_caseExprp->castGenCase()) {
@@ -107,7 +107,7 @@ private:
 	    }
 	}
    }
-    virtual void visit(AstNode* nodep, AstNUser*) {
+    virtual void visit(AstNode* nodep) {
 	nodep->iterateChildren(*this);
    }
 public:
@@ -174,7 +174,7 @@ private:
 	    for (AstNode* icondp = itemp->condsp(); icondp!=NULL; icondp=icondp->nextp()) {
 		//if (debug()>=9) icondp->dumpTree(cout," caseitem: ");
 		AstConst* iconstp = icondp->castConst();
-		if (!iconstp) nodep->v3fatalSrc("above 'can't parse' should have caught this\n");
+		if (!iconstp) nodep->v3fatalSrc("above 'can't parse' should have caught this");
 		if (neverItem(nodep, iconstp)) {
 		    // X in casez can't ever be executed
 		} else {
@@ -423,7 +423,7 @@ private:
 	// Handle any assertions
 	replaceCaseParallel(nodep, false);
 	// Replace the CASE... with IF...
-	if (debug()>=9) grouprootp->dumpTree(cout,"     _new: ");
+	if (debug()>=9 && grouprootp) grouprootp->dumpTree(cout,"     _new: ");
 	if (grouprootp) nodep->replaceWith(grouprootp);
 	else nodep->unlinkFrBack();
 	nodep->deleteTree(); VL_DANGLING(nodep);
@@ -451,7 +451,7 @@ private:
    }

    // VISITORS
-    virtual void visit(AstCase* nodep, AstNUser*) {
+    virtual void visit(AstCase* nodep) {
 	V3Case::caseLint(nodep);
 	nodep->iterateChildren(*this);
 	if (debug()>=9) nodep->dumpTree(cout," case_old: ");
@@ -467,7 +467,7 @@ private:
    }
    //--------------------
    // Default: Just iterate
-    virtual void visit(AstNode* nodep, AstNUser*) {
+    virtual void visit(AstNode* nodep) {
 	nodep->iterateChildren(*this);
    }

@@ -489,7 +489,7 @@ public:
 void V3Case::caseAll(AstNetlist* nodep) {
    UINFO(2,__FUNCTION__<<": "<<endl);
    CaseVisitor visitor (nodep);
-    V3Global::dumpCheckGlobalTree("case.tree", 0, v3Global.opt.dumpTreeLevel(__FILE__) >= 3);
+    V3Global::dumpCheckGlobalTree("case", 0, v3Global.opt.dumpTreeLevel(__FILE__) >= 3);
 }
 void V3Case::caseLint(AstNodeCase* nodep) {
    UINFO(4,__FUNCTION__<<": "<<endl);
@@ -6,7 +6,7 @@
 //
 //*************************************************************************
 //
-// Copyright 2003-2015 by Wilson Snyder.  This program is free software; you can
+// Copyright 2003-2017 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.
@@ -6,7 +6,7 @@
 //
 //*************************************************************************
 //
-// Copyright 2004-2015 by Wilson Snyder.  This program is free software; you can
+// Copyright 2004-2017 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.
@@ -107,19 +107,19 @@ private:
    }

    // VISITORS
-    virtual void visit(AstNodeUniop* nodep, AstNUser*) {
+    virtual void visit(AstNodeUniop* nodep) {
 	nodep->iterateChildren(*this);
 	nodep->user1(nodep->lhsp()->user1());
 	if (nodep->sizeMattersLhs()) insureCast(nodep->lhsp());
    }
-    virtual void visit(AstNodeBiop* nodep, AstNUser*) {
+    virtual void visit(AstNodeBiop* nodep) {
 	nodep->iterateChildren(*this);
 	nodep->user1(nodep->lhsp()->user1()
 		    | nodep->rhsp()->user1());
 	if (nodep->sizeMattersLhs()) insureCast(nodep->lhsp());
 	if (nodep->sizeMattersRhs()) insureCast(nodep->rhsp());
    }
-    virtual void visit(AstNodeTriop* nodep, AstNUser*) {
+    virtual void visit(AstNodeTriop* nodep) {
 	nodep->iterateChildren(*this);
 	nodep->user1(nodep->lhsp()->user1()
 		    | nodep->rhsp()->user1()
@@ -128,12 +128,12 @@ private:
 	if (nodep->sizeMattersRhs()) insureCast(nodep->rhsp());
 	if (nodep->sizeMattersThs()) insureCast(nodep->thsp());
    }
-    virtual void visit(AstCCast* nodep, AstNUser*) {
+    virtual void visit(AstCCast* nodep) {
 	nodep->iterateChildren(*this);
 	insureLower32Cast(nodep);
 	nodep->user1(1);
    }
-    virtual void visit(AstNegate* nodep, AstNUser*) {
+    virtual void visit(AstNegate* nodep) {
 	nodep->iterateChildren(*this);
 	nodep->user1(nodep->lhsp()->user1());
 	if (nodep->lhsp()->widthMin()==1) {
@@ -145,7 +145,7 @@ private:
 	    insureCast(nodep->lhsp());
 	}
    }
-    virtual void visit(AstVarRef* nodep, AstNUser*) {
+    virtual void visit(AstVarRef* nodep) {
 	if (!nodep->lvalue()
 	    && !nodep->backp()->castCCast()
 	    && nodep->backp()->castNodeMath()
@@ -158,7 +158,7 @@ private:
 	}
 	nodep->user1(1);
    }
-    virtual void visit(AstConst* nodep, AstNUser*) {
+    virtual void visit(AstConst* nodep) {
 	// Constants are of unknown size if smaller than 33 bits, becase
 	// we're too lazy to wrap every constant in the universe in
 	// ((IData)#).
@@ -166,11 +166,11 @@ private:
    }

    // NOPs
-    virtual void visit(AstVar* nodep, AstNUser*) {}
+    virtual void visit(AstVar* nodep) {}

    //--------------------
    // Default: Just iterate
-    virtual void visit(AstNode* nodep, AstNUser*) {
+    virtual void visit(AstNode* nodep) {
 	nodep->iterateChildren(*this);
    }

@@ -188,5 +188,5 @@ public:
 void V3Cast::castAll(AstNetlist* nodep) {
    UINFO(2,__FUNCTION__<<": "<<endl);
    CastVisitor visitor (nodep);
-    V3Global::dumpCheckGlobalTree("cast.tree", 0, v3Global.opt.dumpTreeLevel(__FILE__) >= 3);
+    V3Global::dumpCheckGlobalTree("cast", 0, v3Global.opt.dumpTreeLevel(__FILE__) >= 3);
 }
@@ -6,7 +6,7 @@
 //
 //*************************************************************************
 //
-// Copyright 2004-2015 by Wilson Snyder.  This program is free software; you can
+// Copyright 2004-2017 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.
--- a/Show More
+++ b/Show More