Merge 24e61af2c0 into 9f04ee68c8

Extending V3DfgBreakCycles to handle common cases involving unpacked
arrays.

Changes

@@ -13,10 +13,30 @@ Verilator 5.039 devel
 
 **Other:**
 
+* Add ENUMITEMWIDTH error, and apply to X-extended and ranged values.
+* Add NOEFFECT warning, replacing previous `foreach` error.
+* Add SPECIFYIGN warning for specify constructs that were previously silently ignored.
+* Add enum base data type, and wire data type checking per IEEE.
+* Support member-level triggers for virtual interfaces (#5166) (#6148). [Yilou Wang]
+* Support disabling a fork in additional contexts (#5432 partial) (#6174) (#6183). [Ryszard Rozak, Antmicro Ltd.]
 * Support disable dotted references (#6154). [Ryszard Rozak, Antmicro Ltd.]
+* Support randomize() on class member selects (#6161) (#6195). [Igor Zaworski, Ryszard Rozak, Antmicro Ltd.]
+* Support multiple variables on RHS of a `force` assignment (#6163). [Artur Bieniek, Antmicro Ltd.]]
+* Support covergroup extends, etc., as unsupported (#6160). [Artur Bieniek, Antmicro Ltd.]
 * Change control file `public_flat_*` and other signal attributes to support __ in names (#6140).
-* Fix class extends dotted error (#6162). [Igor Zaworski]
+* Fix constructor parameters in inheritance hierarchies (#6036) (#6070). [Petr Nohavica]
+* Fix cmake `-Wno` compiler flag testing (#6145). [Martin Stadler]
+* Fix class extends dotted error (#6162). [Igor Zaworski, Antmicro Ltd.]
 * Fix genvar error with `-O0` (#6165). [Max Wipfli]
+* Fix uninitialized thread PGO counters (#6167). [Bartłomiej Chmiel, Antmicro Ltd.]
+* Fix additional UNOPTFLAT combinational cycles automatically in DFG (#6168) (#6173) (#6176). [Geza Lore]
+* Fix omitting error when assigning to an input (#6169). [Artur Bieniek, Antmicro Ltd.]]
+* Fix param-dependent class typedef linking (#6171). [Igor Zaworski, Antmicro Ltd.]
+* Fix virtual interface member propagation (#6175) (#6184). [Yilou Wang]
+* Fix `--coverage-expr` null pointer dereference (#6181). [Igor Zaworski, Antmicro Ltd.]
+* Fix conflicting function/class name linking error (#6182). [Igor Zaworski, Antmicro Ltd.]
+* Fix VPI signal range order (#6189) (#6200). [Ibrahim Burak Yorulmaz]
+* Fix structure select causing 'Wide Op' error (#6191). [Danny Oler]
 
 
 Verilator 5.038 2025-07-08
@@ -107,7 +127,7 @@ Verilator 5.038 2025-07-08
 * Fix wide non-blocking assignment mis-optimization (#6150) (#6152) (#6155). [Todd Strader]
 * Fix interface array connections with non-zero low declaration index.
 * Fix developer build error on MacOS/Flex2.6.4 (#6153). [Paul Swirhun]
-* Fix crash with --dumpi-V3LinkDot without --debug (#6159). [Igor Zaworski]
+* Fix crash with --dumpi-V3LinkDot without --debug (#6159). [Igor Zaworski, Antmicro Ltd.]
 
 
 Verilator 5.036 2025-04-27

Makefile.in

@@ -470,6 +470,7 @@ CLANGFORMAT_FLAGS = -i
 CLANGFORMAT_FILES = $(CHECK_CPP) $(CHECK_H) $(CHECK_YL) test_regress/t/*.c* test_regress/t/*.h
 
 format-c clang-format:
+	$(CLANGFORMAT) --version
 	@$(CLANGFORMAT) --version | egrep 14.0 > /dev/null \
 	|| echo "*** You are not using clang-format-14, indents may differ from master's ***"
 	$(CLANGFORMAT) $(CLANGFORMAT_FLAGS) $(CLANGFORMAT_FILES)
@@ -538,6 +539,7 @@ YAPF = yapf3
 YAPF_FLAGS = -i --parallel
 
 format-py yapf:
+	$(YAPF) --version
 	$(YAPF) $(YAPF_FLAGS) $(PY_FILES)
 
 GERSEMI = gersemi

docs/CONTRIBUTORS

@@ -37,6 +37,7 @@ Chuxuan Wang
 Chykon
 Conor McCullough
 Dan Petrisko
+Danny Oler
 Daniel Bates
 Dave Sargeant
 David Horton
@@ -84,6 +85,7 @@ Huang Rui
 Huanghuang Zhou
 HungMingWu
 HyungKi Jeong
+Ibrahim Burak Yorulmaz
 Igor Zaworski
 Ilya Barkov
 Iru Cai
@@ -157,6 +159,7 @@ Martin Schmidt
 Martin Stadler
 Mateusz Gancarz
 Matthew Ballance
+Max Wipfli
 Michael Bikovitsky
 Michael Killough
 Michal Czyz

docs/Makefile

@@ -68,11 +68,16 @@ pdf:
 
 ######################################################################
 
-html latex linkcheck spelling::
+html latex linkcheck::
 	$(MAKE) vl-extract
 	$(SPHINXBUILD) -M $@ "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS)
 	$(PYTHON3) bin/vl_sphinx_fix _build
 
+spelling::
+	$(MAKE) vl-extract
+	$(SPHINXBUILD) -M $@ "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS)
+	sort -o guide/spelling.txt guide/spelling.txt
+
 help:
 	@$(SPHINXBUILD) -M help "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS)
 

docs/gen/ex_WIDTHEXPAND_1_faulty.rst

@@ -3,6 +3,6 @@
    :linenos:
    :emphasize-lines: 3
 
-      int array[5];
-      bit [1:0] rd_addr;
-      wire int rd_value = array[rd_addr];  //<--- Warning
+     logic [31:0] array[5];
+     bit [1:0] rd_addr;
+     wire [31:0] rd_value = array[rd_addr];  //<--- Warning

docs/gen/ex_WIDTHEXPAND_1_fixed.rst

@@ -2,4 +2,4 @@
 .. code-block:: sv
    :emphasize-lines: 1
 
-      wire int rd_value = array[{1'b0, rd_addr}];  //<--- Fixed
+     wire [31:0] rd_value = array[{1'b0, rd_addr}];  //<--- Fixed

docs/gen/ex_WIDTHEXPAND_1_msg.rst

@@ -1,4 +1,4 @@
 .. comment: generated by t_lint_widthexpand_docs_bad
 .. code-block::
 
-   %Warning-WIDTHEXPAND: example.v:3:29 Bit extraction of array[4:0] requires 3 bit index, not 2 bits.
+   %Warning-WIDTHEXPAND: example.v:3:31 Bit extraction of array[4:0] requires 3 bit index, not 2 bits.

docs/guide/warnings.rst

@@ -458,7 +458,7 @@ List Of Warnings
 
    Warns that Verilator does not support certain forms of
    :code:`constraint`, :code:`constraint_mode`, or :code:`rand_mode`, and
-   the construct was are ignored.
+   the construct was ignored.
 
    Ignoring this warning may make Verilator randomize() simulations differ
    from other simulators.
@@ -486,7 +486,7 @@ List Of Warnings
 
    Warns that Verilator does not support certain forms of
    :code:`covergroup`, :code:`coverpoint`, and coverage options, and the
-   construct was are ignored.
+   construct was ignored.
 
    Disabling the :option:`UNSUPPORTED` error also disables this warning.
 
@@ -709,6 +709,28 @@ List Of Warnings
    missing."
 
 
+.. option:: ENUMITEMWIDTH
+
+   An error that an enum item value is being assigned from a value which
+   would be truncated (similar to :option:`WIDTHTRUNC`), or from a sized
+   literal constant with a different bit width (similar to
+   :option:`WIDTHTRUNC` or :option:`WIDTHEXPAND`).  IEEE requires this
+   error, but it may be disabled.
+
+   Faulty example:
+
+   .. code-block:: sv
+      :linenos:
+      :emphasize-lines: 2
+
+         typedef enum [3:0] {
+            WRONG_WIDTH = 33'h3  //<--- Warning
+         } enum_t;
+
+   To repair, correct the size of the item's value directly, or use a cast,
+   so the resulting width matches the enum's width.
+
+
 .. option:: ENUMVALUE
 
    An error that an enum data type value is being assigned from another data
@@ -1286,6 +1308,21 @@ List Of Warnings
    simulate correctly.
 
 
+.. option:: NOEFFECT
+
+   Warns that the statement will have no effect and is roughly equivalent
+   to not being present.  This is only issued when it is "non-obvious",
+   e.g. a :code:`if (0)` will not result in this warning.
+
+   Faulty example:
+
+   .. code-block:: sv
+
+         foreach (array[]) begin ... end  //<--- Warning
+
+   For a fix, remove the statement.
+
+
 .. option:: NOLATCH
 
    .. TODO better example
@@ -1742,6 +1779,18 @@ List Of Warnings
    simulators.
 
 
+.. option:: SPECIFYIGN
+
+   Warns that Verilator does not support certain constructs in
+   :code:`specify` blocks, nor :code:`$sdf_annotate`, and the construct was
+   ignored.
+
+   Disabling the :option:`UNSUPPORTED` error also disables this warning.
+
+   Ignoring this warning may make Verilator ignore lint checking on the
+   construct, and get different results from other simulators.
+
+
 .. option:: SPLITVAR
 
    Warns that a variable with a :option:`/*verilator&32;split_var*/`

docs/spelling.txt

@@ -314,6 +314,7 @@ Noack
 Nodine
 Ober
 Oleg
+Oler
 Olof
 Olofsson
 Oron
@@ -481,6 +482,7 @@ Wfuture
 Whatson
 Wildman
 Wim
+Wipfli
 Wmisleading
 Wno
 Wojciech
@@ -600,6 +602,7 @@ coroutines
 countbits
 countones
 cout
+covergroup
 cpp
 cppstyle
 cpu

include/verilated.cpp

@@ -3061,7 +3061,7 @@ void VerilatedContext::statsPrintSummary() VL_MT_UNSAFE {
         = vl_timescaled_double((cputime != 0.0) ? (simtimeInUnits / cputime) : 0, "%0.3f %s");
     VL_PRINTF("- Verilator: %s at %s; walltime %0.3f s; speed %s/s\n", endwhy.c_str(),
               simtime.c_str(), walltime, simtimePerf.c_str());
-    const double modelMB = VlOs::memUsageBytes() / 1024.0 / 1024.0;
+    const double modelMB = VlOs::memPeakUsageBytes() / 1024.0 / 1024.0;
     VL_PRINTF("- Verilator: cpu %0.3f s on %u threads; alloced %0.0f MB\n", cputime,
               threadsInModels(), modelMB);
 }

include/verilated_std.sv

@@ -175,6 +175,14 @@ package std;
 `endif
       endtask
 
+      static task killQueue(ref process processQueue[$]);
+`ifdef VERILATOR_TIMING
+         while (processQueue.size() > 0) begin
+            processQueue.pop_back().kill();
+         end
+`endif
+      endtask
+
       // Two process references are equal if the different classes' containing
       // m_process are equal. Can't yet use <=> as the base class template
       // comparisons doesn't define <=> as they don't yet require --timing and C++20.

include/verilatedos.h

@@ -637,7 +637,7 @@ extern std::string getenvStr(const std::string& envvar,
 extern uint16_t getcpu() VL_MT_SAFE;
 
 /// Return memory usage in bytes, or 0 if unknown
-extern uint64_t memUsageBytes() VL_MT_SAFE;
+extern uint64_t memPeakUsageBytes() VL_MT_SAFE;
 
 // Internal: Record CPU time, starting point on construction, and current delta from that
 class DeltaCpuTime final {

include/verilatedos_c.h

@@ -102,9 +102,9 @@ uint16_t getcpu() VL_MT_SAFE {
 }
 
 //=========================================================================
-// VlOs::memUsageBytes implementation
+// VlOs::memPeakUsageBytes implementation
 
-uint64_t memUsageBytes() VL_MT_SAFE {
+uint64_t memPeakUsageBytes() VL_MT_SAFE {
 #if defined(_WIN32) || defined(__MINGW32__)
     const HANDLE process = GetCurrentProcess();
     PROCESS_MEMORY_COUNTERS pmc;
@@ -124,6 +124,7 @@ uint64_t memUsageBytes() VL_MT_SAFE {
         &size, &resident, &share, &text, &lib, &data, &dt);
     fclose(fp);
     if (VL_UNCOVERABLE(7 != items)) return 0;
+    // Return the vm size, not the current active set size (/proc/self/status VmRSS + VmSwap)
     return (text + data) * getpagesize();
 #endif
 }

src/V3AstNodeExpr.h

@@ -561,6 +561,7 @@ public:
 
 public:
     ASTGEN_MEMBERS_AstAddrOfCFunc;
+    void dump(std::ostream& str) const override;
     string emitVerilog() override { V3ERROR_NA_RETURN(""); }
     string emitC() override { V3ERROR_NA_RETURN(""); }
     bool cleanOut() const override { return true; }

src/V3AstNodeOther.h

@@ -1974,7 +1974,7 @@ class AstVar final : public AstNode {
     bool m_isConst : 1;  // Table contains constant data
     bool m_isContinuously : 1;  // Ever assigned continuously (for force/release)
     bool m_hasStrengthAssignment : 1;  // Is on LHS of assignment with strength specifier
-    bool m_isStatic : 1;  // Static C variable (for Verilog see instead isAutomatic)
+    bool m_isStatic : 1;  // Static C variable (for Verilog see instead lifetime())
     bool m_isPulldown : 1;  // Tri0
     bool m_isPullup : 1;  // Tri1
     bool m_isIfaceParent : 1;  // dtype is reference to interface present in this module
@@ -3057,12 +3057,15 @@ class AstCoverToggle final : public AstNodeStmt {
     // @astgen op1 := incp : AstCoverInc
     // @astgen op2 := origp : AstNodeExpr
     // @astgen op3 := changep : AstNodeExpr
+    // @astgen op4 := initp : Optional[AstNodeExpr]
 public:
-    AstCoverToggle(FileLine* fl, AstCoverInc* incp, AstNodeExpr* origp, AstNodeExpr* changep)
+    AstCoverToggle(FileLine* fl, AstCoverInc* incp, AstNodeExpr* origp, AstNodeExpr* changep,
+                   AstNodeExpr* initp)
         : ASTGEN_SUPER_CoverToggle(fl) {
         this->incp(incp);
         this->origp(origp);
         this->changep(changep);
+        this->initp(initp);
     }
     ASTGEN_MEMBERS_AstCoverToggle;
     int instrCount() const override { return 3 + INSTR_COUNT_BRANCH + INSTR_COUNT_LD; }

src/V3AstNodes.cpp

@@ -189,6 +189,12 @@ void AstNodeCond::numberOperate(V3Number& out, const V3Number& lhs, const V3Numb
     }
 }
 
+void AstAddrOfCFunc::dump(std::ostream& str) const {
+    this->AstNodeExpr::dump(str);
+    str << " -> ";
+    funcp()->dump(str);
+}
+
 void AstBasicDType::init(VBasicDTypeKwd kwd, VSigning numer, int wantwidth, int wantwidthmin,
                          AstRange* rangep) {
     // wantwidth=0 means figure it out, but if a widthmin is >=0
@@ -1110,6 +1116,9 @@ AstNode* AstArraySel::baseFromp(AstNode* nodep, bool overMembers) {
         } else if (overMembers && VN_IS(nodep, MemberSel)) {
             nodep = VN_AS(nodep, MemberSel)->fromp();
             continue;
+        } else if (overMembers && VN_IS(nodep, StructSel)) {
+            nodep = VN_AS(nodep, StructSel)->fromp();
+            continue;
         }
         // AstNodePreSel stashes the associated variable under an ATTROF
         // of VAttrType::VAR_BASE so it isn't constified

src/V3Begin.cpp

@@ -530,7 +530,11 @@ AstNode* V3Begin::convertToWhile(AstForeach* nodep) {
     }
     // The parser validates we don't have "foreach (array[,,,])"
     AstNode* const bodyp = nodep->stmtsp();
-    UASSERT_OBJ(newp, nodep, "foreach has no non-empty loop variable");
+    if (!newp) {
+        nodep->v3warn(NOEFFECT, "foreach with no loop variable has no effect");
+        VL_DO_DANGLING(nodep->unlinkFrBack()->deleteTree(), nodep);
+        return nullptr;
+    }
     if (bodyp) {
         bodyPointp->replaceWith(bodyp->unlinkFrBackWithNext());
     } else {

src/V3Class.cpp

@@ -57,28 +57,18 @@ class ClassVisitor final : public VNVisitor {
 
     // METHODS
 
-    bool recurseImplements(AstClass* nodep, bool setit) {
-        // Returns true to set useVirtualPublic().
-        // If there's an implements of an interface class then we have
-        // multiple classes that point to same object, that need same
-        // VlClass (the diamond problem). C++ will require we use 'virtual
-        // public' for VlClass.  So, we need the interface class, and all
-        // classes above, and any below using any implements to use
-        // 'virtual public' via useVirtualPublic().
-        if (nodep->useVirtualPublic()) return true;  // Short-circuit
-        if (nodep->isInterfaceClass()) setit = true;
+    void recurseImplements(AstClass* nodep) {
+        // In SystemVerilog, we have two inheritance chains:
+        // - extends of concrete clasess: mapped to non-virtual C++ inheritance
+        //   as there is only single ancestor allowed
+        // - implements of concrete classes / extends of interface classes: mapped
+        //   to virtual inheritance to allow diamond patterns with multiple ancestors
+        if (nodep->useVirtualPublic()) return;  // Short-circuit to exit diamond cycles
+        if (nodep->isInterfaceClass()) { nodep->useVirtualPublic(true); }
         for (const AstClassExtends* extp = nodep->extendsp(); extp;
              extp = VN_AS(extp->nextp(), ClassExtends)) {
-            if (recurseImplements(extp->classp(), setit)) setit = true;
+            recurseImplements(extp->classp());
         }
-        if (setit) {
-            nodep->useVirtualPublic(true);
-            for (const AstClassExtends* extp = nodep->extendsp(); extp;
-                 extp = VN_AS(extp->nextp(), ClassExtends)) {
-                (void)recurseImplements(extp->classp(), true);
-            }
-        }
-        return setit;
     }
 
     // VISITORS
@@ -89,7 +79,7 @@ class ClassVisitor final : public VNVisitor {
         nodep->name(m_prefix + nodep->name());
         nodep->unlinkFrBack();
         v3Global.rootp()->addModulesp(nodep);
-        (void)recurseImplements(nodep, false);
+        recurseImplements(nodep);
         // Make containing package
         // Note origName is the same as the class origName so errors look correct
         AstClassPackage* const packagep

src/V3Clock.cpp

@@ -100,23 +100,44 @@ class ClockVisitor final : public VNVisitor {
         // if (debug()) nodep->dumpTree("-  ct: ");
         // COVERTOGGLE(INC, ORIG, CHANGE) ->
         //   IF(ORIG ^ CHANGE) { INC; CHANGE = ORIG; }
-        AstNode* const incp = nodep->incp()->unlinkFrBack();
+        FileLine* fl = nodep->fileline();
+        AstNodeStmt* const incp = nodep->incp()->unlinkFrBack();
         AstNodeExpr* const origp = nodep->origp()->unlinkFrBack();
         AstNodeExpr* const changeWrp = nodep->changep()->unlinkFrBack();
         AstNodeExpr* const changeRdp = ConvertWriteRefsToRead::main(changeWrp->cloneTree(false));
         AstNodeExpr* comparedp = nullptr;
         // Xor will optimize better than Eq, when CoverToggle has bit selects,
-        // but can only use Xor with non-opaque types
+        // but can only use Xor with non-opaque types.
+        // Opaque types aren't accepted by V3Coverage::varIgnoreToggle
         if (const AstBasicDType* const bdtypep
             = VN_CAST(origp->dtypep()->skipRefp(), BasicDType)) {
-            if (!bdtypep->isOpaque()) comparedp = new AstXor{nodep->fileline(), origp, changeRdp};
+            if (!bdtypep->isOpaque()) comparedp = new AstXor{fl, origp, changeRdp};
         }
-        if (!comparedp) comparedp = AstEq::newTyped(nodep->fileline(), origp, changeRdp);
-        AstIf* const newp = new AstIf{nodep->fileline(), comparedp, incp};
+        UASSERT_OBJ(comparedp, nodep, "Toggle coverage of non-opaque type variable");
+        AstNodeStmt* incBodyp;
+        AstIf* initIfp = nullptr;
+        if (nodep->initp()) {
+            if (AstVarRef* const writeRefp = VN_CAST(nodep->initp(), VarRef)) {
+                AstVarRef* const readRefp = writeRefp->cloneTree(false);
+                readRefp->access(VAccess::READ);
+                AstAssign* const initAssignp
+                    = new AstAssign{fl, writeRefp->unlinkFrBack(), new AstConst{fl, 2}};
+                initIfp = new AstIf{fl, new AstEq{fl, readRefp, new AstConst{fl, 1}}, initAssignp};
+                incBodyp
+                    = new AstIf{fl, new AstEq{fl, readRefp->cloneTree(false), new AstConst{fl, 2}},
+                                incp, initIfp->cloneTree(false)};
+            } else {
+                nodep->initp()->v3fatalSrc("Initp is not a var ref");
+                incBodyp = nullptr;
+            }
+        } else {
+            incBodyp = incp;
+        }
+        AstIf* const newp = new AstIf{fl, comparedp, incBodyp, initIfp};
         // We could add another IF to detect posedges, and only increment if so.
         // It's another whole branch though versus a potential memory miss.
         // We'll go with the miss.
-        newp->addThensp(new AstAssign{nodep->fileline(), changeWrp, origp->cloneTree(false)});
+        newp->addThensp(new AstAssign{fl, changeWrp, origp->cloneTree(false)});
         nodep->replaceWith(newp);
         VL_DO_DANGLING(nodep->deleteTree(), nodep);
     }

src/V3Const.cpp

@@ -1267,8 +1267,12 @@ class ConstVisitor final : public VNVisitor {
                 && nodep->lhsp()->isPure());
     }
     bool operandIsTwo(const AstNode* nodep) {
-        return (VN_IS(nodep, Const) && !VN_AS(nodep, Const)->num().isFourState()
-                && nodep->width() <= VL_QUADSIZE && VN_AS(nodep, Const)->toUQuad() == 2);
+        const AstConst* const constp = VN_CAST(nodep, Const);
+        if (!constp) return false;  // not constant
+        if (constp->num().isFourState()) return false;  // four-state
+        if (nodep->width() > VL_QUADSIZE) return false;  // too wide
+        if (nodep->isSigned() && constp->num().isNegative()) return false;  // signed and negative
+        return constp->toUQuad() == 2;
     }
     bool operandIsTwostate(const AstNode* nodep) {
         return (VN_IS(nodep, Const) && !VN_AS(nodep, Const)->num().isFourState());
@@ -3550,6 +3554,7 @@ class ConstVisitor final : public VNVisitor {
     TREEOP ("AstDiv   {$lhsp, operandIsPowTwo($rhsp)}", "replaceDivShift(nodep)");  // a/2^n -> a>>n
     TREEOP ("AstModDiv{$lhsp, operandIsPowTwo($rhsp)}", "replaceModAnd(nodep)");  // a % 2^n -> a&(2^n-1)
     TREEOP ("AstPow   {operandIsTwo($lhsp), !$rhsp.isZero}",    "replacePowShift(nodep)");  // 2**a == 1<<a
+    TREEOP ("AstPowSU {operandIsTwo($lhsp), !$rhsp.isZero}",    "replacePowShift(nodep)");  // 2**a == 1<<a
     TREEOP ("AstSub   {$lhsp.castAdd, operandSubAdd(nodep)}", "AstAdd{AstSub{$lhsp->castAdd()->lhsp(),$rhsp}, $lhsp->castAdd()->rhsp()}");  // ((a+x)-y) -> (a+(x-y))
     TREEOPC("AstAnd   {$lhsp.isOne, matchRedundantClean(nodep)}", "DONE")  // 1 & (a == b) -> (IData)(a == b)
     // Trinary ops

src/V3Coverage.cpp

@@ -39,17 +39,28 @@ class ExprCoverageEligibleVisitor final : public VNVisitor {
     // STATE
     bool m_eligible = true;
 
+    static bool elemDTypeEligible(const AstNodeDType* dtypep) {
+        dtypep = dtypep->skipRefp();
+        if (AstNodeDType* const dtp = dtypep->virtRefDTypep()) {
+            if (!elemDTypeEligible(dtp)) return false;
+        }
+        if (AstNodeDType* const dtp = dtypep->virtRefDType2p()) {
+            if (!elemDTypeEligible(dtp)) return false;
+        }
+        return !VN_IS(dtypep, ClassRefDType);
+    }
+
     void visit(AstNodeVarRef* nodep) override {
         AstNodeDType* dtypep = nodep->varp()->dtypep();
-        // Class objecs and references not supported for expression coverage
+        // Class objects and references not supported for expression coverage
         // because the object may not persist until the point at which
         // coverage data is gathered
         // This could be resolved in the future by protecting against dereferrencing
         // null pointers when cloning the expression for expression coverage
-        if (VN_CAST(dtypep, ClassRefDType)) {
-            m_eligible = false;
-        } else {
+        if (dtypep && elemDTypeEligible(dtypep)) {
             iterateChildren(nodep);
+        } else {
+            m_eligible = false;
         }
     }
 
@@ -92,14 +103,17 @@ class CoverageVisitor final : public VNVisitor {
         const string m_comment;  // Comment for coverage dump
         AstNodeExpr* m_varRefp;  // How to get to this element
         AstNodeExpr* m_chgRefp;  // How to get to this element
-        ToggleEnt(const string& comment, AstNodeExpr* vp, AstNodeExpr* cp)
+        AstNodeExpr* m_initRefp;  // Expression that stores initialization status
+        ToggleEnt(const string& comment, AstNodeExpr* vp, AstNodeExpr* cp, AstNodeExpr* initp)
             : m_comment{comment}
             , m_varRefp{vp}
-            , m_chgRefp{cp} {}
+            , m_chgRefp{cp}
+            , m_initRefp{initp} {}
         ~ToggleEnt() = default;
         void cleanup() {
             VL_DO_CLEAR(m_varRefp->deleteTree(), m_varRefp = nullptr);
             VL_DO_CLEAR(m_chgRefp->deleteTree(), m_chgRefp = nullptr);
+            if (m_initRefp) { VL_DO_CLEAR(m_initRefp->deleteTree(), m_initRefp = nullptr); }
         }
     };
 
@@ -376,16 +390,55 @@ class CoverageVisitor final : public VNVisitor {
                 const string newvarname = "__Vtogcov__"s + m_beginHier + nodep->shortName();
                 FileLine* const fl_nowarn = new FileLine{nodep->fileline()};
                 fl_nowarn->modifyWarnOff(V3ErrorCode::UNUSEDSIGNAL, true);
+                fl_nowarn->modifyWarnOff(V3ErrorCode::ALWCOMBORDER, true);
+                fl_nowarn->modifyWarnOff(V3ErrorCode::MULTIDRIVEN, true);
+                fl_nowarn->modifyWarnOff(V3ErrorCode::UNOPTFLAT, true);
+                fl_nowarn->coverageOn(false);
                 AstVar* const chgVarp
                     = new AstVar{fl_nowarn, VVarType::MODULETEMP, newvarname, nodep};
                 m_modp->addStmtsp(chgVarp);
 
+                AstVar* initVarp = nullptr;
+                AstVarRef* initWriteRefp = nullptr;
+                // We need to exclude top module input ports, because they can't have value x.
+                // TODO: Exclude also variables driven by top module input ports
+                const bool isTopModuleInput
+                    = (v3Global.rootp()->topModulep() == m_modp) && nodep->isInput();
+                const AstBasicDType* const basicDTypep
+                    = VN_CAST(nodep->dtypep()->skipRefp(), BasicDType);
+                if (basicDTypep && basicDTypep->isFourstate() && basicDTypep->isBitLogic()
+                    && !basicDTypep->isRanged() && !isTopModuleInput) {
+                    const string initVarName
+                        = "__Vtogcovinit__"s + m_beginHier + nodep->shortName();
+                    AstBasicDType* const initDtypep
+                        = new AstBasicDType{fl_nowarn, VBasicDTypeKwd::INT, VSigning::NOSIGN};
+                    v3Global.rootp()->typeTablep()->addTypesp(initDtypep);
+                    initVarp
+                        = new AstVar{fl_nowarn, VVarType::MODULETEMP, initVarName, initDtypep};
+                    m_modp->addStmtsp(initVarp);
+                    initWriteRefp = new AstVarRef{fl_nowarn, initVarp, VAccess::WRITE};
+                    AstAssign* const assignp
+                        = new AstAssign{fl_nowarn, initWriteRefp->cloneTree(false),
+                                        new AstConst{fl_nowarn, AstConst::All1{}}};
+                    AstIf* const ifp = new AstIf{
+                        fl_nowarn,
+                        new AstEq{fl_nowarn, new AstVarRef{fl_nowarn, initVarp, VAccess::READ},
+                                  new AstConst{fl_nowarn, AstConst::All0{}}},
+                        assignp};
+                    AstSenTree* const sentreep = new AstSenTree{
+                        fl_nowarn, new AstSenItem{fl_nowarn, VEdgeType::ET_CHANGED,
+                                                  new AstVarRef{fl_nowarn, nodep, VAccess::READ}}};
+                    AstAlways* const alwaysp
+                        = new AstAlways{fl_nowarn, VAlwaysKwd::ALWAYS, sentreep, ifp};
+                    m_modp->addStmtsp(alwaysp);
+                }
+
                 // Create bucket for each dimension * bit.
                 // This is necessarily an O(n^2) expansion, which is why
                 // we limit coverage to signals with < 256 bits.
 
                 ToggleEnt newvec{""s, new AstVarRef{fl_nowarn, nodep, VAccess::READ},
-                                 new AstVarRef{fl_nowarn, chgVarp, VAccess::WRITE}};
+                                 new AstVarRef{fl_nowarn, chgVarp, VAccess::WRITE}, initWriteRefp};
                 toggleVarRecurse(nodep->dtypeSkipRefp(), 0, newvec, nodep);
                 newvec.cleanup();
             }
@@ -399,7 +452,8 @@ class CoverageVisitor final : public VNVisitor {
             varp->fileline(),
             newCoverInc(varp->fileline(), "", "v_toggle",
                         hierPrefix + varp->name() + above.m_comment, "", 0, ""),
-            above.m_varRefp->cloneTree(false), above.m_chgRefp->cloneTree(false)};
+            above.m_varRefp->cloneTree(false), above.m_chgRefp->cloneTree(false),
+            above.m_initRefp ? above.m_initRefp->cloneTree(false) : nullptr};
         m_modp->addStmtsp(newp);
     }
 
@@ -414,7 +468,12 @@ class CoverageVisitor final : public VNVisitor {
                                      new AstSel{varp->fileline(),
                                                 above.m_varRefp->cloneTree(false), index_code, 1},
                                      new AstSel{varp->fileline(),
-                                                above.m_chgRefp->cloneTree(false), index_code, 1}};
+                                                above.m_chgRefp->cloneTree(false), index_code, 1},
+                                     above.m_initRefp
+                                         ? new AstSel{varp->fileline(),
+                                                      above.m_initRefp->cloneTree(false),
+                                                      index_code, 1}
+                                         : nullptr};
                     toggleVarBottom(newent, varp);
                     newent.cleanup();
                 }
@@ -428,7 +487,12 @@ class CoverageVisitor final : public VNVisitor {
                                  new AstArraySel{varp->fileline(),
                                                  above.m_varRefp->cloneTree(false), index_code},
                                  new AstArraySel{varp->fileline(),
-                                                 above.m_chgRefp->cloneTree(false), index_code}};
+                                                 above.m_chgRefp->cloneTree(false), index_code},
+                                 above.m_initRefp
+                                     ? new AstArraySel{varp->fileline(),
+                                                       above.m_initRefp->cloneTree(false),
+                                                       index_code}
+                                     : nullptr};
                 toggleVarRecurse(adtypep->subDTypep()->skipRefp(), depth + 1, newent, varp);
                 newent.cleanup();
             }
@@ -436,11 +500,16 @@ class CoverageVisitor final : public VNVisitor {
             for (int index_docs = adtypep->lo(); index_docs <= adtypep->hi(); ++index_docs) {
                 const AstNodeDType* const subtypep = adtypep->subDTypep()->skipRefp();
                 const int index_code = index_docs - adtypep->lo();
-                ToggleEnt newent{above.m_comment + "["s + cvtToStr(index_docs) + "]",
-                                 new AstSel{varp->fileline(), above.m_varRefp->cloneTree(false),
-                                            index_code * subtypep->width(), subtypep->width()},
-                                 new AstSel{varp->fileline(), above.m_chgRefp->cloneTree(false),
-                                            index_code * subtypep->width(), subtypep->width()}};
+                ToggleEnt newent{
+                    above.m_comment + "["s + cvtToStr(index_docs) + "]",
+                    new AstSel{varp->fileline(), above.m_varRefp->cloneTree(false),
+                               index_code * subtypep->width(), subtypep->width()},
+                    new AstSel{varp->fileline(), above.m_chgRefp->cloneTree(false),
+                               index_code * subtypep->width(), subtypep->width()},
+                    above.m_initRefp
+                        ? new AstSel{varp->fileline(), above.m_initRefp->cloneTree(false),
+                                     index_code * subtypep->width(), subtypep->width()}
+                        : nullptr};
                 toggleVarRecurse(adtypep->subDTypep()->skipRefp(), depth + 1, newent, varp);
                 newent.cleanup();
             }
@@ -455,7 +524,11 @@ class CoverageVisitor final : public VNVisitor {
                         new AstSel{varp->fileline(), above.m_varRefp->cloneTree(false), index_code,
                                    subtypep->width()},
                         new AstSel{varp->fileline(), above.m_chgRefp->cloneTree(false), index_code,
-                                   subtypep->width()}};
+                                   subtypep->width()},
+                        above.m_initRefp
+                            ? new AstSel{varp->fileline(), above.m_initRefp->cloneTree(false),
+                                         index_code, subtypep->width()}
+                            : nullptr};
                     toggleVarRecurse(subtypep, depth + 1, newent, varp);
                     newent.cleanup();
                 }
@@ -467,9 +540,16 @@ class CoverageVisitor final : public VNVisitor {
                         varp->fileline(), above.m_varRefp->cloneTree(false), itemp->name()};
                     AstNodeExpr* const chgRefp = new AstStructSel{
                         varp->fileline(), above.m_chgRefp->cloneTree(false), itemp->name()};
+                    AstNodeExpr* const initRefp
+                        = above.m_initRefp
+                              ? new AstStructSel{varp->fileline(),
+                                                 above.m_initRefp->cloneTree(false), itemp->name()}
+                              : nullptr;
                     varRefp->dtypep(subtypep);
                     chgRefp->dtypep(subtypep);
-                    ToggleEnt newent{above.m_comment + "."s + itemp->name(), varRefp, chgRefp};
+                    initRefp->dtypep(subtypep);
+                    ToggleEnt newent{above.m_comment + "."s + itemp->name(), varRefp, chgRefp,
+                                     initRefp};
                     toggleVarRecurse(subtypep, depth + 1, newent, varp);
                     newent.cleanup();
                 }
@@ -479,9 +559,10 @@ class CoverageVisitor final : public VNVisitor {
             if (const AstMemberDType* const itemp = adtypep->membersp()) {
                 AstNodeDType* const subtypep = itemp->subDTypep()->skipRefp();
                 if (adtypep->packed()) {
-                    ToggleEnt newent{above.m_comment + "."s + itemp->name(),
-                                     above.m_varRefp->cloneTree(false),
-                                     above.m_chgRefp->cloneTree(false)};
+                    ToggleEnt newent{
+                        above.m_comment + "."s + itemp->name(), above.m_varRefp->cloneTree(false),
+                        above.m_chgRefp->cloneTree(false),
+                        above.m_initRefp ? above.m_initRefp->cloneTree(false) : nullptr};
                     toggleVarRecurse(subtypep, depth + 1, newent, varp);
                     newent.cleanup();
                 } else {
@@ -489,9 +570,16 @@ class CoverageVisitor final : public VNVisitor {
                         varp->fileline(), above.m_varRefp->cloneTree(false), itemp->name()};
                     AstNodeExpr* const chgRefp = new AstStructSel{
                         varp->fileline(), above.m_chgRefp->cloneTree(false), itemp->name()};
+                    AstNodeExpr* const initRefp
+                        = above.m_initRefp
+                              ? new AstStructSel{varp->fileline(),
+                                                 above.m_initRefp->cloneTree(false), itemp->name()}
+                              : nullptr;
                     varRefp->dtypep(subtypep);
                     chgRefp->dtypep(subtypep);
-                    ToggleEnt newent{above.m_comment + "."s + itemp->name(), varRefp, chgRefp};
+                    initRefp->dtypep(subtypep);
+                    ToggleEnt newent{above.m_comment + "."s + itemp->name(), varRefp, chgRefp,
+                                     initRefp};
                     toggleVarRecurse(subtypep, depth + 1, newent, varp);
                     newent.cleanup();
                 }
@@ -858,7 +946,6 @@ class CoverageVisitor final : public VNVisitor {
                             != strs[!term.m_objective].end())
                             impossible = true;
                     }
-
                     if (!redundant) expr.push_back(term);
                 }
                 if (!impossible) m_exprs.push_back(std::move(expr));

src/V3Delayed.cpp

@@ -1265,6 +1265,9 @@ class DelayedVisitor final : public VNVisitor {
     void visit(AstAssignPost*) override {}
     void visit(AstAlwaysPost*) override {}
 
+    // Children of AstCoverToggle aren't part of assignments
+    void visit(AstCoverToggle* nodep) override {}
+
     //--------------------
     void visit(AstNode* nodep) override { iterateChildren(nodep); }
 

src/V3Dfg.cpp

@@ -97,6 +97,16 @@ std::unique_ptr<DfgGraph> DfgGraph::clone() const {
             vtxp2clonep.emplace(&vtx, cp);
             break;
         }
+        case VDfgType::atSpliceArray: {
+            DfgSpliceArray* const cp = new DfgSpliceArray{*clonep, vtx.fileline(), vtx.dtypep()};
+            vtxp2clonep.emplace(&vtx, cp);
+            break;
+        }
+        case VDfgType::atSplicePacked: {
+            DfgSplicePacked* const cp = new DfgSplicePacked{*clonep, vtx.fileline(), vtx.dtypep()};
+            vtxp2clonep.emplace(&vtx, cp);
+            break;
+        }
         default: {
             vtx.v3fatalSrc("Unhandled operation vertex type: " + vtx.typeName());
             VL_UNREACHABLE;
@@ -109,49 +119,55 @@ std::unique_ptr<DfgGraph> DfgGraph::clone() const {
     // Constants have no inputs
     // Hook up inputs of cloned variables
     for (const DfgVertexVar& vtx : m_varVertices) {
-        switch (vtx.type()) {
-        case VDfgType::atVarArray: {
-            const DfgVarArray* const vp = vtx.as<DfgVarArray>();
-            DfgVarArray* const cp = vtxp2clonep.at(vp)->as<DfgVarArray>();
-            vp->forEachSourceEdge([&](const DfgEdge& edge, size_t i) {
-                if (DfgVertex* const srcp = edge.sourcep()) {
-                    cp->addDriver(vp->driverFileLine(i),  //
-                                  vp->driverIndex(i),  //
-                                  vtxp2clonep.at(srcp));
-                }
-            });
-            break;
-        }
-        case VDfgType::atVarPacked: {
-            const DfgVarPacked* const vp = vtx.as<DfgVarPacked>();
-            DfgVarPacked* const cp = vtxp2clonep.at(vp)->as<DfgVarPacked>();
-            vp->forEachSourceEdge([&](const DfgEdge& edge, size_t i) {
-                if (DfgVertex* const srcp = edge.sourcep()) {
-                    cp->addDriver(vp->driverFileLine(i),  //
-                                  vp->driverLsb(i),  //
-                                  vtxp2clonep.at(srcp));
-                }
-            });
-            break;
-        }
-        default: {
-            vtx.v3fatalSrc("Unhandled variable vertex type: " + vtx.typeName());
-            VL_UNREACHABLE;
-            break;
-        }
+        // All variable vertices are unary
+        if (DfgVertex* const srcp = vtx.srcp()) {
+            vtxp2clonep.at(&vtx)->as<DfgVertexVar>()->srcp(vtxp2clonep.at(srcp));
         }
     }
     // Hook up inputs of cloned operation vertices
     for (const DfgVertex& vtx : m_opVertices) {
-        DfgVertex* const cp = vtxp2clonep.at(&vtx);
-        // The code below doesn't work for DfgVertexVariadic, but none of the opVertices are such.
-        UASSERT_OBJ(!vtx.is<DfgVertexVariadic>(), &vtx, "DfgVertexVariadic not handled");
-        const auto oSourceEdges = vtx.sourceEdges();
-        auto cSourceEdges = cp->sourceEdges();
-        UASSERT_OBJ(oSourceEdges.second == cSourceEdges.second, &vtx, "Mismatched source count");
-        for (size_t i = 0; i < oSourceEdges.second; ++i) {
-            if (DfgVertex* const srcp = oSourceEdges.first[i].sourcep()) {
-                cSourceEdges.first[i].relinkSource(vtxp2clonep.at(srcp));
+        if (vtx.is<DfgVertexVariadic>()) {
+            switch (vtx.type()) {
+            case VDfgType::atSpliceArray: {
+                const DfgSpliceArray* const vp = vtx.as<DfgSpliceArray>();
+                DfgSpliceArray* const cp = vtxp2clonep.at(vp)->as<DfgSpliceArray>();
+                vp->forEachSourceEdge([&](const DfgEdge& edge, size_t i) {
+                    if (DfgVertex* const srcp = edge.sourcep()) {
+                        cp->addDriver(vp->driverFileLine(i),  //
+                                      vp->driverIndex(i),  //
+                                      vtxp2clonep.at(srcp));
+                    }
+                });
+                break;
+            }
+            case VDfgType::atSplicePacked: {
+                const DfgSplicePacked* const vp = vtx.as<DfgSplicePacked>();
+                DfgSplicePacked* const cp = vtxp2clonep.at(vp)->as<DfgSplicePacked>();
+                vp->forEachSourceEdge([&](const DfgEdge& edge, size_t i) {
+                    if (DfgVertex* const srcp = edge.sourcep()) {
+                        cp->addDriver(vp->driverFileLine(i),  //
+                                      vp->driverLsb(i),  //
+                                      vtxp2clonep.at(srcp));
+                    }
+                });
+                break;
+            }
+            default: {
+                vtx.v3fatalSrc("Unhandled DfgVertexVariadic sub type: " + vtx.typeName());
+                VL_UNREACHABLE;
+                break;
+            }
+            }
+        } else {
+            DfgVertex* const cp = vtxp2clonep.at(&vtx);
+            const auto oSourceEdges = vtx.sourceEdges();
+            auto cSourceEdges = cp->sourceEdges();
+            UASSERT_OBJ(oSourceEdges.second == cSourceEdges.second, &vtx,
+                        "Mismatched source count");
+            for (size_t i = 0; i < oSourceEdges.second; ++i) {
+                if (DfgVertex* const srcp = oSourceEdges.first[i].sourcep()) {
+                    cSourceEdges.first[i].relinkSource(vtxp2clonep.at(srcp));
+                }
             }
         }
     }
@@ -230,8 +246,9 @@ static void dumpDotVertex(std::ostream& os, const DfgVertex& vtx) {
         AstNode* const nodep = varVtxp->nodep();
         AstVar* const varp = varVtxp->varp();
         os << toDotId(vtx);
-        os << " [label=\"" << nodep->name() << "\nW" << varVtxp->width() << " / F"
-           << varVtxp->fanout() << '"';
+        os << " [label=\"" << nodep->name() << "\n";
+        varVtxp->dtypep()->dumpSmall(os);
+        os << " / F" << varVtxp->fanout() << '"';
 
         if (varp->direction() == VDirection::INPUT) {
             os << ", shape=box, style=filled, fillcolor=chartreuse2";  // Green
@@ -257,9 +274,10 @@ static void dumpDotVertex(std::ostream& os, const DfgVertex& vtx) {
     if (const DfgVarArray* const arrVtxp = vtx.cast<DfgVarArray>()) {
         AstNode* const nodep = arrVtxp->nodep();
         AstVar* const varp = arrVtxp->varp();
-        const int elements = VN_AS(arrVtxp->dtypep(), UnpackArrayDType)->elementsConst();
         os << toDotId(vtx);
-        os << " [label=\"" << nodep->name() << "[" << elements << "]\"";
+        os << " [label=\"" << nodep->name() << "\n";
+        arrVtxp->dtypep()->dumpSmall(os);
+        os << " / F" << arrVtxp->fanout() << '"';
         if (varp->direction() == VDirection::INPUT) {
             os << ", shape=box3d, style=filled, fillcolor=chartreuse2";  // Green
         } else if (varp->direction() == VDirection::OUTPUT) {
@@ -302,8 +320,9 @@ static void dumpDotVertex(std::ostream& os, const DfgVertex& vtx) {
         const uint32_t lsb = selVtxp->lsb();
         const uint32_t msb = lsb + selVtxp->width() - 1;
         os << toDotId(vtx);
-        os << " [label=\"SEL\n_[" << msb << ":" << lsb << "]\nW" << vtx.width() << " / F"
-           << vtx.fanout() << '"';
+        os << " [label=\"SEL\n_[" << msb << ":" << lsb << "]\n";
+        vtx.dtypep()->dumpSmall(os);
+        os << " / F" << vtx.fanout() << '"';
         if (vtx.hasMultipleSinks()) {
             os << ", shape=doublecircle";
         } else {
@@ -313,8 +332,24 @@ static void dumpDotVertex(std::ostream& os, const DfgVertex& vtx) {
         return;
     }
 
+    if (vtx.is<DfgVertexSplice>()) {
+        os << toDotId(vtx);
+        os << " [label=\"" << vtx.typeName() << "\n";
+        vtx.dtypep()->dumpSmall(os);
+        os << " / F" << vtx.fanout() << '"';
+        if (vtx.hasMultipleSinks()) {
+            os << ", shape=doubleoctagon";
+        } else {
+            os << ", shape=octagon";
+        }
+        os << "]\n";
+        return;
+    }
+
     os << toDotId(vtx);
-    os << " [label=\"" << vtx.typeName() << "\nW" << vtx.width() << " / F" << vtx.fanout() << '"';
+    os << " [label=\"" << vtx.typeName() << "\n";
+    vtx.dtypep()->dumpSmall(os);
+    os << " / F" << vtx.fanout() << '"';
     if (vtx.hasMultipleSinks()) {
         os << ", shape=doublecircle";
     } else {
@@ -336,7 +371,7 @@ static void dumpDotVertexAndSourceEdges(std::ostream& os, const DfgVertex& vtx)
     vtx.forEachSourceEdge([&](const DfgEdge& edge, size_t idx) {  //
         if (edge.sourcep()) {
             string headLabel;
-            if (vtx.arity() > 1 || vtx.is<DfgVertexVar>()) headLabel = vtx.srcName(idx);
+            if (vtx.arity() > 1 || vtx.is<DfgVertexSplice>()) headLabel = vtx.srcName(idx);
             dumpDotEdge(os, edge, headLabel);
         }
     });
@@ -521,24 +556,34 @@ bool DfgVertex::selfEquals(const DfgVertex& that) const { return true; }
 V3Hash DfgVertex::selfHash() const { return V3Hash{}; }
 
 bool DfgVertex::equals(const DfgVertex& that, EqualsCache& cache) const {
+    // If same vertex, then equal
     if (this == &that) return true;
+
+    // If different type, then not equal
     if (this->type() != that.type()) return false;
+
+    // If different data type, then not equal
     if (this->dtypep() != that.dtypep()) return false;
+
+    // If different number of inputs, then not equal
+    auto thisPair = this->sourceEdges();
+    const DfgEdge* const thisSrcEdgesp = thisPair.first;
+    const size_t thisArity = thisPair.second;
+    auto thatPair = that.sourceEdges();
+    const DfgEdge* const thatSrcEdgesp = thatPair.first;
+    const size_t thatArity = thatPair.second;
+    if (thisArity != thatArity) return false;
+
+    // Check vertex specifics
     if (!this->selfEquals(that)) return false;
 
+    // Check sources
     const auto key = (this < &that) ? EqualsCache::key_type{this, &that}  //
                                     : EqualsCache::key_type{&that, this};
     // Note: the recursive invocation can cause a re-hash but that will not invalidate references
     uint8_t& result = cache[key];
     if (!result) {
         result = 2;  // Assume equals
-        auto thisPair = this->sourceEdges();
-        const DfgEdge* const thisSrcEdgesp = thisPair.first;
-        const size_t thisArity = thisPair.second;
-        auto thatPair = that.sourceEdges();
-        const DfgEdge* const thatSrcEdgesp = thatPair.first;
-        const size_t thatArity = thatPair.second;
-        UASSERT_OBJ(thisArity == thatArity, this, "Same type vertices must have same arity!");
         for (size_t i = 0; i < thisArity; ++i) {
             const DfgVertex* const thisSrcVtxp = thisSrcEdgesp[i].m_sourcep;
             const DfgVertex* const thatSrcVtxp = thatSrcEdgesp[i].m_sourcep;
@@ -561,7 +606,12 @@ V3Hash DfgVertex::hash() {
         // variables, which we rely on.
         if (!is<DfgVertexVar>()) {
             hash += m_type;
-            hash += width();  // Currently all non-variable vertices are packed, so this is safe
+            if (AstUnpackArrayDType* const adtypep = VN_CAST(dtypep(), UnpackArrayDType)) {
+                hash += adtypep->elementsConst();
+                // TODO: maybe include sub-dtype, but not hugely important at the moment
+            } else {
+                hash += width();
+            }
             const auto pair = sourceEdges();
             const DfgEdge* const edgesp = pair.first;
             const size_t arity = pair.second;
@@ -579,22 +629,16 @@ uint32_t DfgVertex::fanout() const {
     return result;
 }
 
-DfgVarPacked* DfgVertex::getResultVar() {
-    UASSERT_OBJ(!this->is<DfgVarArray>(), this, "Arrays are not supported by " << __FUNCTION__);
-
+DfgVertexVar* DfgVertex::getResultVar() {
     // It's easy if the vertex is already a variable ...
-    if (DfgVarPacked* const varp = this->cast<DfgVarPacked>()) return varp;
+    if (DfgVertexVar* const varp = this->cast<DfgVertexVar>()) return varp;
 
-    // Inspect existing variables fully written by this vertex, and choose one
-    DfgVarPacked* resp = nullptr;
+    // Inspect existing variables written by this vertex, and choose one
+    DfgVertexVar* resp = nullptr;
     // cppcheck-has-bug-suppress constParameter
     this->forEachSink([&resp](DfgVertex& sink) {
-        DfgVarPacked* const varp = sink.cast<DfgVarPacked>();
+        DfgVertexVar* const varp = sink.cast<DfgVertexVar>();
         if (!varp) return;
-        if (!varp->isDrivenFullyByDfg()) return;
-        // Ignore SystemC variables, they cannot participate in expressions or
-        // be assigned rvalue expressions.
-        if (varp->varp()->isSc()) return;
         // First variable found
         if (!resp) {
             resp = varp;
@@ -694,6 +738,42 @@ bool DfgSel::selfEquals(const DfgVertex& that) const { return lsb() == that.as<D
 
 V3Hash DfgSel::selfHash() const { return V3Hash{lsb()}; }
 
+// DfgSpliceArray ----------
+
+bool DfgSpliceArray::selfEquals(const DfgVertex& that) const {
+    const DfgSpliceArray* const thatp = that.as<DfgSpliceArray>();
+    const size_t arity = this->arity();
+    for (size_t i = 0; i < arity; ++i) {
+        if (driverIndex(i) != thatp->driverIndex(i)) return false;
+    }
+    return true;
+}
+
+V3Hash DfgSpliceArray::selfHash() const {
+    V3Hash hash;
+    const size_t arity = this->arity();
+    for (size_t i = 0; i < arity; ++i) hash += driverIndex(i);
+    return hash;
+}
+
+// DfgSplicePacked ----------
+
+bool DfgSplicePacked::selfEquals(const DfgVertex& that) const {
+    const DfgSplicePacked* const thatp = that.as<DfgSplicePacked>();
+    const size_t arity = this->arity();
+    for (size_t i = 0; i < arity; ++i) {
+        if (driverLsb(i) != thatp->driverLsb(i)) return false;
+    }
+    return true;
+}
+
+V3Hash DfgSplicePacked::selfHash() const {
+    V3Hash hash;
+    const size_t arity = this->arity();
+    for (size_t i = 0; i < arity; ++i) hash += driverLsb(i);
+    return hash;
+}
+
 // DfgVertexVar ----------
 
 bool DfgVertexVar::selfEquals(const DfgVertex& that) const {

src/V3Dfg.h

@@ -230,7 +230,13 @@ public:
 
     // Retrieve user data, must be current.
     template <typename T>
-    inline T& getUser();
+    inline const T& getUser() const;
+
+    // Retrieve user data, must be current.
+    template <typename T>
+    T& getUser() {
+        return const_cast<T&>(const_cast<const DfgVertex*>(this)->getUser<T>());
+    }
 
     // Set user data, becomes current.
     template <typename T>
@@ -238,8 +244,7 @@ public:
 
     // Width of result
     uint32_t width() const {
-        // This is a hot enough function that this is an expensive check, so in debug build only.
-        UDEBUGONLY(UASSERT_OBJ(VN_IS(dtypep(), BasicDType), this, "non-packed has no 'width()'"););
+        UASSERT_OBJ(VN_IS(dtypep(), BasicDType), this, "non-packed has no 'width()'");
         return dtypep()->width();
     }
 
@@ -283,7 +288,7 @@ public:
 
     // Return a canonical variable vertex that holds the value of this vertex,
     // or nullptr if no such variable exists in the graph. This is O(fanout).
-    DfgVarPacked* getResultVar() VL_MT_DISABLED;
+    DfgVertexVar* getResultVar() VL_MT_DISABLED;
 
     // Cache type for 'scopep' below
     using ScopeCache = std::unordered_map<const DfgVertex*, AstScope*>;
@@ -572,7 +577,7 @@ class DfgVertexVariadic VL_NOT_FINAL : public DfgVertex {
 
 protected:
     DfgVertexVariadic(DfgGraph& dfg, VDfgType type, FileLine* flp, AstNodeDType* dtypep,
-                      uint32_t initialCapacity = 1)
+                      uint32_t initialCapacity)
         : DfgVertex{dfg, type, flp, dtypep}
         , m_srcsp{allocSources(initialCapacity)}
         , m_srcCap{initialCapacity} {}
@@ -784,12 +789,12 @@ T& DfgVertex::user() {
 }
 
 template <typename T>
-T& DfgVertex::getUser() {
+const T& DfgVertex::getUser() const {
     static_assert(sizeof(T) <= sizeof(UserDataStorage),
                   "Size of user data type 'T' is too large for allocated storage");
     static_assert(alignof(T) <= alignof(UserDataStorage),
                   "Alignment of user data type 'T' is larger than allocated storage");
-    T* const storagep = reinterpret_cast<T*>(&m_userDataStorage);
+    const T* const storagep = reinterpret_cast<const T*>(&m_userDataStorage);
 #if VL_DEBUG
     const uint32_t userCurrent = m_graphp->m_userCurrent;
     UASSERT_OBJ(userCurrent, this, "DfgVertex user data used without reserving");
@@ -914,18 +919,19 @@ bool DfgVertex::isOnes() const {
 // Inline method definitions - for DfgVertexVar
 //------------------------------------------------------------------------------
 
-DfgVertexVar::DfgVertexVar(DfgGraph& dfg, VDfgType type, AstVar* varp, uint32_t initialCapacity)
-    : DfgVertexVariadic{dfg, type, varp->fileline(), dtypeFor(varp), initialCapacity}
+DfgVertexVar::DfgVertexVar(DfgGraph& dfg, VDfgType type, AstVar* varp)
+    : DfgVertexUnary{dfg, type, varp->fileline(), dtypeFor(varp)}
     , m_varp{varp}
     , m_varScopep{nullptr} {
     UASSERT_OBJ(dfg.modulep(), varp, "Un-scoped DfgVertexVar created in scoped DfgGraph");
+    UASSERT_OBJ(!m_varp->isSc(), varp, "SystemC variable is not representable by DfgVertexVar");
 }
-DfgVertexVar::DfgVertexVar(DfgGraph& dfg, VDfgType type, AstVarScope* vscp,
-                           uint32_t initialCapacity)
-    : DfgVertexVariadic{dfg, type, vscp->fileline(), dtypeFor(vscp), initialCapacity}
+DfgVertexVar::DfgVertexVar(DfgGraph& dfg, VDfgType type, AstVarScope* vscp)
+    : DfgVertexUnary{dfg, type, vscp->fileline(), dtypeFor(vscp)}
     , m_varp{vscp->varp()}
     , m_varScopep{vscp} {
     UASSERT_OBJ(!dfg.modulep(), vscp, "Scoped DfgVertexVar created in un-scoped DfgGraph");
+    UASSERT_OBJ(!m_varp->isSc(), vscp, "SystemC variable is not representable by DfgVertexVar");
 }
 
 //------------------------------------------------------------------------------

src/V3DfgAstToDfg.cpp

@@ -28,9 +28,12 @@
 
 #include "V3PchAstNoMT.h"  // VL_MT_DISABLED_CODE_UNIT
 
+#include "V3Const.h"
 #include "V3Dfg.h"
 #include "V3DfgPasses.h"
 
+#include <iterator>
+
 VL_DEFINE_DEBUG_FUNCTIONS;
 
 namespace {
@@ -42,6 +45,17 @@ T_Vertex* makeVertex(const T_Node* nodep, DfgGraph& dfg) {
     return new T_Vertex{dfg, nodep->fileline(), DfgVertex::dtypeFor(nodep)};
 }
 
+template <>
+DfgArraySel* makeVertex<DfgArraySel, AstArraySel>(const AstArraySel* nodep, DfgGraph& dfg) {
+    // Some earlier passes create malformed ArraySels, just bail on those...
+    // See t_bitsel_wire_array_bad
+    if (VN_IS(nodep->fromp(), Const)) return nullptr;
+    AstUnpackArrayDType* const fromDtypep
+        = VN_CAST(nodep->fromp()->dtypep()->skipRefp(), UnpackArrayDType);
+    if (!fromDtypep) return nullptr;
+    return new DfgArraySel{dfg, nodep->fileline(), DfgVertex::dtypeFor(nodep)};
+}
+
 //======================================================================
 // Currently unhandled nodes
 // LCOV_EXCL_START
@@ -77,17 +91,6 @@ class AstToDfgVisitor final : public VNVisitor {
     const VNUser1InUse m_user1InUse;
 
     // TYPES
-    // Represents a driver during canonicalization
-    struct Driver final {
-        FileLine* m_fileline;
-        DfgVertex* m_vtxp;
-        uint32_t m_lsb;
-        Driver(FileLine* flp, uint32_t lsb, DfgVertex* vtxp)
-            : m_fileline{flp}
-            , m_vtxp{vtxp}
-            , m_lsb{lsb} {}
-    };
-
     using RootType = std::conditional_t<T_Scoped, AstNetlist, AstModule>;
     using VariableType = std::conditional_t<T_Scoped, AstVarScope, AstVar>;
 
@@ -122,8 +125,9 @@ class AstToDfgVisitor final : public VNVisitor {
 
     void markReferenced(AstNode* nodep) {
         nodep->foreach([this](const AstVarRef* refp) {
-            // No need to (and in fact cannot) mark variables with unsupported dtypes
-            if (!DfgVertex::isSupportedDType(refp->varp()->dtypep())) return;
+            // No need to (and in fact cannot) mark variables if:
+            if (!DfgVertex::isSupportedDType(refp->varp()->dtypep())) return;  //  unsupported type
+            if (refp->varp()->isSc()) return;  // SystemC
             VariableType* const tgtp = getTarget(refp);
             // Mark vertex as having a module reference outside current DFG
             getNet(tgtp)->setHasModRefs();
@@ -183,75 +187,144 @@ class AstToDfgVisitor final : public VNVisitor {
         return m_foundUnhandled;
     }
 
-    // Build DfgEdge representing the LValue assignment. Returns false if unsuccessful.
-    bool convertAssignment(FileLine* flp, AstNode* nodep, DfgVertex* vtxp) {
+    std::pair<DfgVertexSplice*, uint32_t> convertLValue(AstNode* nodep) {
         if (AstVarRef* const vrefp = VN_CAST(nodep, VarRef)) {
             m_foundUnhandled = false;
             visit(vrefp);
-            // cppcheck-has-bug-suppress knownConditionTrueFalse
-            if (m_foundUnhandled) return false;
-            getVertex(vrefp)->template as<DfgVarPacked>()->addDriver(flp, 0, vtxp);
-            return true;
+            if (m_foundUnhandled) return {nullptr, 0};
+
+            // Get the variable vertex
+            DfgVertexVar* const vtxp = getVertex(vrefp)->template as<DfgVertexVar>();
+            // Ensure the Splice driver exists for this variable
+            if (!vtxp->srcp()) {
+                FileLine* const flp = vtxp->fileline();
+                AstNodeDType* const dtypep = vtxp->dtypep();
+                if (vtxp->is<DfgVarPacked>()) {
+                    vtxp->srcp(new DfgSplicePacked{*m_dfgp, flp, dtypep});
+                } else if (vtxp->is<DfgVarArray>()) {
+                    vtxp->srcp(new DfgSpliceArray{*m_dfgp, flp, dtypep});
+                } else {
+                    nodep->v3fatalSrc("Unhandled DfgVertexVar sub-type");  // LCOV_EXCL_LINE
+                }
+            }
+            // Return the Splice driver
+            return {vtxp->srcp()->as<DfgVertexSplice>(), 0};
         }
-        if (AstSel* const selp = VN_CAST(nodep, Sel)) {
-            AstVarRef* const vrefp = VN_CAST(selp->fromp(), VarRef);
+
+        if (AstSel* selp = VN_CAST(nodep, Sel)) {
+            // Only handle constant selects
             const AstConst* const lsbp = VN_CAST(selp->lsbp(), Const);
-            if (!vrefp || !lsbp) {
+            if (!lsbp) {
                 ++m_ctx.m_nonRepLhs;
-                return false;
+                return {nullptr, 0};
             }
-            m_foundUnhandled = false;
-            visit(vrefp);
-            // cppcheck-has-bug-suppress knownConditionTrueFalse
-            if (m_foundUnhandled) return false;
-            getVertex(vrefp)->template as<DfgVarPacked>()->addDriver(flp, lsbp->toUInt(), vtxp);
-            return true;
-        }
-        if (AstArraySel* const selp = VN_CAST(nodep, ArraySel)) {
-            AstVarRef* const vrefp = VN_CAST(selp->fromp(), VarRef);
-            const AstConst* const idxp = VN_CAST(selp->bitp(), Const);
-            if (!vrefp || !idxp) {
-                ++m_ctx.m_nonRepLhs;
-                return false;
-            }
-            m_foundUnhandled = false;
-            visit(vrefp);
-            // cppcheck-has-bug-suppress knownConditionTrueFalse
-            if (m_foundUnhandled) return false;
-            getVertex(vrefp)->template as<DfgVarArray>()->addDriver(flp, idxp->toUInt(), vtxp);
-            return true;
-        }
-        if (AstConcat* const concatp = VN_CAST(nodep, Concat)) {
-            AstNode* const lhsp = concatp->lhsp();
-            AstNode* const rhsp = concatp->rhsp();
+            uint32_t lsb = lsbp->toUInt();
 
-            {
-                FileLine* const lFlp = lhsp->fileline();
-                DfgSel* const lVtxp = new DfgSel{*m_dfgp, lFlp, DfgVertex::dtypeFor(lhsp)};
+            // Convert the 'fromp' sub-expression
+            const auto pair = convertLValue(selp->fromp());
+            if (!pair.first) return {nullptr, 0};
+            DfgSplicePacked* const splicep = pair.first->template as<DfgSplicePacked>();
+            // Adjust index.
+            lsb += pair.second;
+
+            // AstSel doesn't change type kind (array vs packed), so we can use
+            // the existing splice driver with adjusted lsb
+            return {splicep, lsb};
+        }
+
+        if (AstArraySel* const aselp = VN_CAST(nodep, ArraySel)) {
+            // Only handle constant selects
+            const AstConst* const indexp = VN_CAST(aselp->bitp(), Const);
+            if (!indexp) {
+                ++m_ctx.m_nonRepLhs;
+                return {nullptr, 0};
+            }
+            uint32_t index = indexp->toUInt();
+
+            // Convert the 'fromp' sub-expression
+            const auto pair = convertLValue(aselp->fromp());
+            if (!pair.first) return {nullptr, 0};
+            DfgSpliceArray* const splicep = pair.first->template as<DfgSpliceArray>();
+            // Adjust index. Note pair.second is always 0, but we might handle array slices later..
+            index += pair.second;
+
+            // Ensure the Splice driver exists for this element
+            if (!splicep->driverAt(index)) {
+                FileLine* const flp = nodep->fileline();
+                AstNodeDType* const dtypep = DfgVertex::dtypeFor(nodep);
+                if (VN_IS(dtypep, BasicDType)) {
+                    splicep->addDriver(flp, index, new DfgSplicePacked{*m_dfgp, flp, dtypep});
+                } else if (VN_IS(dtypep, UnpackArrayDType)) {
+                    splicep->addDriver(flp, index, new DfgSpliceArray{*m_dfgp, flp, dtypep});
+                } else {
+                    nodep->v3fatalSrc("Unhandled AstNodeDType sub-type");  // LCOV_EXCL_LINE
+                }
+            }
+
+            // Return the splice driver
+            return {splicep->driverAt(index)->as<DfgVertexSplice>(), 0};
+        }
+
+        ++m_ctx.m_nonRepLhs;
+        return {nullptr, 0};
+    }
+
+    // Build DfgEdge representing the LValue assignment. Returns false if unsuccessful.
+    bool convertAssignment(FileLine* flp, AstNode* lhsp, DfgVertex* vtxp) {
+        // Simplify the LHS, to get rid of things like SEL(CONCAT(_, _), _)
+        lhsp = V3Const::constifyExpensiveEdit(lhsp);
+
+        // Concatenation on the LHS. Select parts of the driving 'vtxp' then convert each part
+        if (AstConcat* const concatp = VN_CAST(lhsp, Concat)) {
+            AstNode* const cLhsp = concatp->lhsp();
+            AstNode* const cRhsp = concatp->rhsp();
+
+            {  // Convet LHS of concat
+                FileLine* const lFlp = cLhsp->fileline();
+                DfgSel* const lVtxp = new DfgSel{*m_dfgp, lFlp, DfgVertex::dtypeFor(cLhsp)};
                 lVtxp->fromp(vtxp);
-                lVtxp->lsb(rhsp->width());
-                if (!convertAssignment(flp, lhsp, lVtxp)) return false;
+                lVtxp->lsb(cRhsp->width());
+                if (!convertAssignment(flp, cLhsp, lVtxp)) return false;
             }
 
-            {
-                FileLine* const rFlp = rhsp->fileline();
-                DfgSel* const rVtxp = new DfgSel{*m_dfgp, rFlp, DfgVertex::dtypeFor(rhsp)};
+            {  // Convert RHS of concat
+                FileLine* const rFlp = cRhsp->fileline();
+                DfgSel* const rVtxp = new DfgSel{*m_dfgp, rFlp, DfgVertex::dtypeFor(cRhsp)};
                 rVtxp->fromp(vtxp);
                 rVtxp->lsb(0);
-                return convertAssignment(flp, rhsp, rVtxp);
+                return convertAssignment(flp, cRhsp, rVtxp);
             }
         }
-        ++m_ctx.m_nonRepLhs;
-        return false;
+
+        // Construct LHS
+        const auto pair = convertLValue(lhsp);
+        if (!pair.first) return false;
+
+        // If successful connect the driver
+        if (DfgSplicePacked* const sPackedp = pair.first->template cast<DfgSplicePacked>()) {
+            sPackedp->addDriver(flp, pair.second, vtxp);
+        } else if (DfgSpliceArray* const sArrayp = pair.first->template cast<DfgSpliceArray>()) {
+            sArrayp->addDriver(flp, pair.second, vtxp);
+        } else {
+            lhsp->v3fatalSrc("Unhandled DfgVertexSplice sub-type");  // LCOV_EXCL_LINE
+        }
+
+        return true;
     }
 
     bool convertEquation(AstNode* nodep, FileLine* flp, AstNode* lhsp, AstNode* rhsp) {
         UASSERT_OBJ(m_uncommittedVertices.empty(), nodep, "Should not nest");
 
-        // Currently cannot handle direct assignments between unpacked types. These arise e.g.
-        // when passing an unpacked array through a module port.
-        if (!DfgVertex::isSupportedPackedDType(lhsp->dtypep())
-            || !DfgVertex::isSupportedPackedDType(rhsp->dtypep())) {
+        // Check data types are compatible.
+        if (!DfgVertex::isSupportedDType(lhsp->dtypep())
+            || !DfgVertex::isSupportedDType(rhsp->dtypep())) {
+            markReferenced(nodep);
+            ++m_ctx.m_nonRepDType;
+            return false;
+        }
+
+        // For now, only direct array assignment is supported (e.g. a = b, but not a = _ ? b : c)
+        if (VN_IS(rhsp->dtypep()->skipRefp(), UnpackArrayDType) && !VN_IS(rhsp, VarRef)) {
             markReferenced(nodep);
             ++m_ctx.m_nonRepDType;
             return false;
@@ -294,166 +367,310 @@ class AstToDfgVisitor final : public VNVisitor {
         return true;
     }
 
-    // Sometime assignment ranges are coalesced by V3Const,
-    // so we unpack concatenations for better error reporting.
-    void addDriver(FileLine* flp, uint32_t lsb, DfgVertex* vtxp,
-                   std::vector<Driver>& drivers) const {
-        if (DfgConcat* const concatp = vtxp->cast<DfgConcat>()) {
-            DfgVertex* const rhsp = concatp->rhsp();
-            auto const rhs_width = rhsp->width();
-            addDriver(rhsp->fileline(), lsb, rhsp, drivers);
-            DfgVertex* const lhsp = concatp->lhsp();
-            addDriver(lhsp->fileline(), lsb + rhs_width, lhsp, drivers);
-            concatp->unlinkDelete(*m_dfgp);
-        } else {
-            drivers.emplace_back(flp, lsb, vtxp);
+    // Prune vertices potentially unused due to resolving multiple drivers.
+    // Having multiple drivers is an error and is hence assumed to be rare,
+    // so performance is not very important, set will suffice.
+    void removeUnused(std::set<DfgVertex*>& prune) {
+        while (!prune.empty()) {
+            // Pop last vertex
+            const auto it = prune.begin();
+            DfgVertex* const vtxp = *it;
+            prune.erase(it);
+            // If used (or a variable), then done
+            if (vtxp->hasSinks() || vtxp->is<DfgVertexVar>()) continue;
+            // If unused, then add sources to work list and delete
+            vtxp->forEachSource([&](DfgVertex& src) { prune.emplace(&src); });
+            vtxp->unlinkDelete(*m_dfgp);
         }
     }
 
-    // Canonicalize packed variables
-    void canonicalizePacked() {
-        for (DfgVarPacked* const varp : m_varPackedps) {
-            // Delete variables with no sinks nor sources (this can happen due to reverting
-            // uncommitted vertices, which does not remove variables)
-            if (!varp->hasSinks() && varp->arity() == 0) {
-                VL_DO_DANGLING(varp->unlinkDelete(*m_dfgp), varp);
+    // Normalize packed driver - return the normalized vertex and location for 'splicep'
+    std::pair<DfgVertex*, FileLine*>  //
+    normalizePacked(DfgVertexVar* varp, const std::string& sub, DfgSplicePacked* const splicep) {
+        // Represents a driver of 'splicep'
+        struct Driver final {
+            FileLine* m_fileline;
+            DfgVertex* m_vtxp;
+            uint32_t m_lsb;
+            Driver() = delete;
+            Driver(FileLine* flp, uint32_t lsb, DfgVertex* vtxp)
+                : m_fileline{flp}
+                , m_vtxp{vtxp}
+                , m_lsb{lsb} {}
+        };
+
+        // The drivers of 'splicep'
+        std::vector<Driver> drivers;
+        drivers.reserve(splicep->arity());
+
+        // Sometime assignment ranges are coalesced by V3Const,
+        // so we unpack concatenations for better error reporting.
+        const std::function<void(FileLine*, uint32_t, DfgVertex*)> gather
+            = [&](FileLine* flp, uint32_t lsb, DfgVertex* vtxp) -> void {
+            if (DfgConcat* const concatp = vtxp->cast<DfgConcat>()) {
+                DfgVertex* const rhsp = concatp->rhsp();
+                auto const rhs_width = rhsp->width();
+                gather(rhsp->fileline(), lsb, rhsp);
+                DfgVertex* const lhsp = concatp->lhsp();
+                gather(lhsp->fileline(), lsb + rhs_width, lhsp);
+                concatp->unlinkDelete(*m_dfgp);
+            } else {
+                drivers.emplace_back(flp, lsb, vtxp);
+            }
+        };
+
+        // Gather and unlink all drivers
+        splicep->forEachSourceEdge([&](DfgEdge& edge, size_t idx) {
+            DfgVertex* const driverp = edge.sourcep();
+            UASSERT(driverp, "Should not have created undriven sources");
+            UASSERT_OBJ(!driverp->is<DfgVertexSplice>(), splicep, "Should not be DfgVertexSplice");
+            gather(splicep->driverFileLine(idx), splicep->driverLsb(idx), driverp);
+            edge.unlinkSource();
+        });
+
+        const auto cmp = [](const Driver& a, const Driver& b) {
+            if (a.m_lsb != b.m_lsb) return a.m_lsb < b.m_lsb;
+            return a.m_fileline->operatorCompare(*b.m_fileline) < 0;
+        };
+
+        // Sort drivers by LSB
+        std::stable_sort(drivers.begin(), drivers.end(), cmp);
+
+        // Vertices that might have become unused due to multiple driver resolution. Having
+        // multiple drivers is an error and is hence assumed to be rare, so performance is
+        // not very important, set will suffice.
+        std::set<DfgVertex*> prune;
+
+        // Fix multiply driven ranges
+        for (auto it = drivers.begin(); it != drivers.end();) {
+            Driver& a = *it++;
+            const uint32_t aWidth = a.m_vtxp->width();
+            const uint32_t aEnd = a.m_lsb + aWidth;
+            while (it != drivers.end()) {
+                Driver& b = *it;
+                // If no overlap, then nothing to do
+                if (b.m_lsb >= aEnd) break;
+
+                const uint32_t bWidth = b.m_vtxp->width();
+                const uint32_t bEnd = b.m_lsb + bWidth;
+                const uint32_t overlapEnd = std::min(aEnd, bEnd) - 1;
+
+                if (a.m_fileline->operatorCompare(*b.m_fileline) != 0
+                    && !varp->varp()->isUsedLoopIdx()  // Loop index often abused, so suppress
+                ) {
+                    AstNode* const vp = varp->varScopep()
+                                            ? static_cast<AstNode*>(varp->varScopep())
+                                            : static_cast<AstNode*>(varp->varp());
+
+                    vp->v3warn(  //
+                        MULTIDRIVEN,
+                        "Bits ["  //
+                            << overlapEnd << ":" << b.m_lsb << "] of signal '" << vp->prettyName()
+                            << sub << "' have multiple combinational drivers\n"
+                            << a.m_fileline->warnOther() << "... Location of first driver\n"
+                            << a.m_fileline->warnContextPrimary() << '\n'
+                            << b.m_fileline->warnOther() << "... Location of other driver\n"
+                            << b.m_fileline->warnContextSecondary() << vp->warnOther()
+                            << "... Only the first driver will be respected");
+                }
+
+                // If the first driver completely covers the range of the second driver,
+                // we can just delete the second driver completely, otherwise adjust the
+                // second driver to apply from the end of the range of the first driver.
+                if (aEnd >= bEnd) {
+                    prune.emplace(b.m_vtxp);
+                    it = drivers.erase(it);
+                } else {
+                    const auto dtypep = DfgVertex::dtypeForWidth(bEnd - aEnd);
+                    DfgSel* const selp = new DfgSel{*m_dfgp, b.m_vtxp->fileline(), dtypep};
+                    selp->fromp(b.m_vtxp);
+                    selp->lsb(aEnd - b.m_lsb);
+                    b.m_lsb = aEnd;
+                    b.m_vtxp = selp;
+                    std::stable_sort(it, drivers.end(), cmp);
+                }
+            }
+        }
+
+        // Coalesce adjacent ranges
+        for (size_t i = 0, j = 1; j < drivers.size(); ++j) {
+            Driver& a = drivers[i];
+            Driver& b = drivers[j];
+
+            // Coalesce adjacent range
+            const uint32_t aWidth = a.m_vtxp->width();
+            const uint32_t bWidth = b.m_vtxp->width();
+            if (a.m_lsb + aWidth == b.m_lsb) {
+                const auto dtypep = DfgVertex::dtypeForWidth(aWidth + bWidth);
+                DfgConcat* const concatp = new DfgConcat{*m_dfgp, a.m_fileline, dtypep};
+                concatp->rhsp(a.m_vtxp);
+                concatp->lhsp(b.m_vtxp);
+                a.m_vtxp = concatp;
+                b.m_vtxp = nullptr;  // Mark as moved
+                ++m_ctx.m_coalescedAssignments;
                 continue;
             }
 
-            // Gather (and unlink) all drivers
-            std::vector<Driver> drivers;
-            drivers.reserve(varp->arity());
-            varp->forEachSourceEdge([this, varp, &drivers](DfgEdge& edge, size_t idx) {
-                DfgVertex* const driverp = edge.sourcep();
-                UASSERT(driverp, "Should not have created undriven sources");
-                addDriver(varp->driverFileLine(idx), varp->driverLsb(idx), driverp, drivers);
-                edge.unlinkSource();
-            });
+            ++i;
 
-            const auto cmp = [](const Driver& a, const Driver& b) {
-                if (a.m_lsb != b.m_lsb) return a.m_lsb < b.m_lsb;
-                return a.m_fileline->operatorCompare(*b.m_fileline) < 0;
-            };
-
-            // Sort drivers by LSB
-            std::stable_sort(drivers.begin(), drivers.end(), cmp);
-
-            // Vertices that might have become unused due to multiple driver resolution. Having
-            // multiple drivers is an error and is hence assumed to be rare, so performance is
-            // not very important, set will suffice.
-            std::set<DfgVertex*> prune;
-
-            // Fix multiply driven ranges
-            for (auto it = drivers.begin(); it != drivers.end();) {
-                Driver& a = *it++;
-                const uint32_t aWidth = a.m_vtxp->width();
-                const uint32_t aEnd = a.m_lsb + aWidth;
-                while (it != drivers.end()) {
-                    Driver& b = *it;
-                    // If no overlap, then nothing to do
-                    if (b.m_lsb >= aEnd) break;
-
-                    const uint32_t bWidth = b.m_vtxp->width();
-                    const uint32_t bEnd = b.m_lsb + bWidth;
-                    const uint32_t overlapEnd = std::min(aEnd, bEnd) - 1;
-
-                    if (a.m_fileline->operatorCompare(*b.m_fileline) != 0
-                        && !varp->varp()->isUsedLoopIdx()  // Loop index often abused, so suppress
-                    ) {
-                        AstNode* const vp = varp->varScopep()
-                                                ? static_cast<AstNode*>(varp->varScopep())
-                                                : static_cast<AstNode*>(varp->varp());
-                        vp->v3warn(  //
-                            MULTIDRIVEN,
-                            "Bits ["  //
-                                << overlapEnd << ":" << b.m_lsb << "] of signal "
-                                << vp->prettyNameQ() << " have multiple combinational drivers\n"
-                                << a.m_fileline->warnOther() << "... Location of first driver\n"
-                                << a.m_fileline->warnContextPrimary() << '\n'
-                                << b.m_fileline->warnOther() << "... Location of other driver\n"
-                                << b.m_fileline->warnContextSecondary() << vp->warnOther()
-                                << "... Only the first driver will be respected");
-                    }
-
-                    // If the first driver completely covers the range of the second driver,
-                    // we can just delete the second driver completely, otherwise adjust the
-                    // second driver to apply from the end of the range of the first driver.
-                    if (aEnd >= bEnd) {
-                        prune.emplace(b.m_vtxp);
-                        it = drivers.erase(it);
-                    } else {
-                        const auto dtypep = DfgVertex::dtypeForWidth(bEnd - aEnd);
-                        DfgSel* const selp = new DfgSel{*m_dfgp, b.m_vtxp->fileline(), dtypep};
-                        selp->fromp(b.m_vtxp);
-                        selp->lsb(aEnd - b.m_lsb);
-                        b.m_lsb = aEnd;
-                        b.m_vtxp = selp;
-                        std::stable_sort(it, drivers.end(), cmp);
-                    }
-                }
-            }
-
-            // Coalesce adjacent ranges
-            for (size_t i = 0, j = 1; j < drivers.size(); ++j) {
-                Driver& a = drivers[i];
-                Driver& b = drivers[j];
-
-                // Coalesce adjacent range
-                const uint32_t aWidth = a.m_vtxp->width();
-                const uint32_t bWidth = b.m_vtxp->width();
-                if (a.m_lsb + aWidth == b.m_lsb) {
-                    const auto dtypep = DfgVertex::dtypeForWidth(aWidth + bWidth);
-                    DfgConcat* const concatp = new DfgConcat{*m_dfgp, a.m_fileline, dtypep};
-                    concatp->rhsp(a.m_vtxp);
-                    concatp->lhsp(b.m_vtxp);
-                    a.m_vtxp = concatp;
-                    b.m_vtxp = nullptr;  // Mark as moved
-                    ++m_ctx.m_coalescedAssignments;
-                    continue;
-                }
-
-                ++i;
-
-                // Compact non-adjacent ranges within the vector
-                if (j != i) {
-                    Driver& c = drivers[i];
-                    UASSERT_OBJ(!c.m_vtxp, c.m_fileline, "Should have been marked moved");
-                    c = b;
-                    b.m_vtxp = nullptr;  // Mark as moved
-                }
-            }
-
-            // Reinsert drivers in order
-            varp->resetSources();
-            for (const Driver& driver : drivers) {
-                if (!driver.m_vtxp) break;  // Stop at end of compacted list
-                varp->addDriver(driver.m_fileline, driver.m_lsb, driver.m_vtxp);
-            }
-
-            // Prune vertices potentially unused due to resolving multiple drivers.
-            while (!prune.empty()) {
-                // Pop last vertex
-                const auto it = prune.begin();
-                DfgVertex* const vtxp = *it;
-                prune.erase(it);
-                // If used (or a variable), then done
-                if (vtxp->hasSinks() || vtxp->is<DfgVertexVar>()) continue;
-                // If unused, then add sources to work list and delete
-                vtxp->forEachSource([&](DfgVertex& src) { prune.emplace(&src); });
-                vtxp->unlinkDelete(*m_dfgp);
+            // Compact non-adjacent ranges within the vector
+            if (j != i) {
+                Driver& c = drivers[i];
+                UASSERT_OBJ(!c.m_vtxp, c.m_fileline, "Should have been marked moved");
+                c = b;
+                b.m_vtxp = nullptr;  // Mark as moved
             }
         }
+
+        // Reinsert drivers in order
+        splicep->resetSources();
+        for (const Driver& driver : drivers) {
+            if (!driver.m_vtxp) break;  // Stop at end of compacted list
+            splicep->addDriver(driver.m_fileline, driver.m_lsb, driver.m_vtxp);
+        }
+
+        removeUnused(prune);
+
+        // If the whole variable is driven whole, we can just use that driver
+        if (splicep->arity() == 1  //
+            && splicep->driverLsb(0) == 0  //
+            && splicep->source(0)->width() == splicep->width()) {
+            const auto result = std::make_pair(splicep->source(0), splicep->driverFileLine(0));
+            VL_DO_DANGLING(splicep->unlinkDelete(*m_dfgp), splicep);
+            return result;
+        }
+        return {splicep, splicep->fileline()};
     }
 
-    // Canonicalize array variables
-    void canonicalizeArray() {
-        for (DfgVarArray* const varp : m_varArrayps) {
-            // Delete variables with no sinks nor sources (this can happen due to reverting
-            // uncommitted vertices, which does not remove variables)
-            if (!varp->hasSinks() && varp->arity() == 0) {
-                VL_DO_DANGLING(varp->unlinkDelete(*m_dfgp), varp);
+    // Normalize array driver - return the normalized vertex and location for 'splicep'
+    std::pair<DfgVertex*, FileLine*>  //
+    normalizeArray(DfgVertexVar* varp, const std::string& sub, DfgSpliceArray* const splicep) {
+        // Represents a driver of 'splicep'
+        struct Driver final {
+            FileLine* m_fileline;
+            DfgVertex* m_vtxp;
+            uint32_t m_idx;
+            Driver() = delete;
+            Driver(FileLine* flp, uint32_t idx, DfgVertex* vtxp)
+                : m_fileline{flp}
+                , m_vtxp{vtxp}
+                , m_idx{idx} {}
+        };
+
+        // The drivers of 'splicep'
+        std::vector<Driver> drivers;
+        drivers.reserve(splicep->arity());
+
+        // Normalize, gather, and unlink all drivers
+        splicep->forEachSourceEdge([&](DfgEdge& edge, size_t i) {
+            DfgVertex* const driverp = edge.sourcep();
+            UASSERT(driverp, "Should not have created undriven sources");
+            const uint32_t idx = splicep->driverIndex(i);
+            if (DfgSplicePacked* const spp = driverp->cast<DfgSplicePacked>()) {
+                const auto pair
+                    = normalizePacked(varp, sub + "[" + std::to_string(idx) + "]", spp);
+                drivers.emplace_back(pair.second, idx, pair.first);
+            } else if (DfgSpliceArray* const sap = driverp->cast<DfgSpliceArray>()) {
+                const auto pair = normalizeArray(varp, sub + "[" + std::to_string(idx) + "]", sap);
+                drivers.emplace_back(pair.second, idx, pair.first);
+            } else if (driverp->is<DfgVertexSplice>()) {
+                driverp->v3fatalSrc("Unhandled DfgVertexSplice sub-type");
+            } else {
+                drivers.emplace_back(splicep->driverFileLine(i), idx, driverp);
+            }
+            edge.unlinkSource();
+        });
+
+        const auto cmp = [](const Driver& a, const Driver& b) {
+            if (a.m_idx != b.m_idx) return a.m_idx < b.m_idx;
+            return a.m_fileline->operatorCompare(*b.m_fileline) < 0;
+        };
+
+        // Sort drivers by index
+        std::stable_sort(drivers.begin(), drivers.end(), cmp);
+
+        // Vertices that become unused due to multiple driver resolution
+        std::set<DfgVertex*> prune;
+
+        // Fix multiply driven ranges
+        for (auto it = drivers.begin(); it != drivers.end();) {
+            Driver& a = *it++;
+            AstUnpackArrayDType* aArrayDTypep = VN_CAST(a.m_vtxp->dtypep(), UnpackArrayDType);
+            const uint32_t aElements = aArrayDTypep ? aArrayDTypep->elementsConst() : 1;
+            const uint32_t aEnd = a.m_idx + aElements;
+            while (it != drivers.end()) {
+                Driver& b = *it;
+                // If no overlap, then nothing to do
+                if (b.m_idx >= aEnd) break;
+
+                AstUnpackArrayDType* bArrayDTypep = VN_CAST(b.m_vtxp->dtypep(), UnpackArrayDType);
+                const uint32_t bElements = bArrayDTypep ? bArrayDTypep->elementsConst() : 1;
+                const uint32_t bEnd = b.m_idx + bElements;
+                const uint32_t overlapEnd = std::min(aEnd, bEnd) - 1;
+
+                if (a.m_fileline->operatorCompare(*b.m_fileline) != 0) {
+                    AstNode* const vp = varp->varScopep()
+                                            ? static_cast<AstNode*>(varp->varScopep())
+                                            : static_cast<AstNode*>(varp->varp());
+
+                    vp->v3warn(  //
+                        MULTIDRIVEN,
+                        "Elements ["  //
+                            << overlapEnd << ":" << b.m_idx << "] of signal '" << vp->prettyName()
+                            << sub << "' have multiple combinational drivers\n"
+                            << a.m_fileline->warnOther() << "... Location of first driver\n"
+                            << a.m_fileline->warnContextPrimary() << '\n'
+                            << b.m_fileline->warnOther() << "... Location of other driver\n"
+                            << b.m_fileline->warnContextSecondary() << vp->warnOther()
+                            << "... Only the first driver will be respected");
+                }
+
+                // If the first driver completely covers the range of the second driver,
+                // we can just delete the second driver completely, otherwise adjust the
+                // second driver to apply from the end of the range of the first driver.
+                if (aEnd >= bEnd) {
+                    prune.emplace(b.m_vtxp);
+                    it = drivers.erase(it);
+                } else {
+                    const auto distance = std::distance(drivers.begin(), it);
+                    DfgVertex* const bVtxp = b.m_vtxp;
+                    FileLine* const flp = b.m_vtxp->fileline();
+                    AstNodeDType* const elemDtypep = DfgVertex::dtypeFor(
+                        VN_AS(splicep->dtypep(), UnpackArrayDType)->subDTypep());
+                    // Remove this driver
+                    it = drivers.erase(it);
+                    // Add missing items element-wise
+                    for (uint32_t i = aEnd; i < bEnd; ++i) {
+                        DfgArraySel* const aselp = new DfgArraySel{*m_dfgp, flp, elemDtypep};
+                        aselp->fromp(bVtxp);
+                        aselp->bitp(new DfgConst{*m_dfgp, flp, 32, i});
+                        drivers.emplace_back(flp, i, aselp);
+                    }
+                    it = drivers.begin();
+                    std::advance(it, distance);
+                    std::stable_sort(it, drivers.end(), cmp);
+                }
             }
         }
+
+        // Reinsert drivers in order
+        splicep->resetSources();
+        for (const Driver& driver : drivers) {
+            if (!driver.m_vtxp) break;  // Stop at end of compacted list
+            splicep->addDriver(driver.m_fileline, driver.m_idx, driver.m_vtxp);
+        }
+
+        removeUnused(prune);
+
+        // If the whole variable is driven whole, we can just use that driver
+        if (splicep->arity() == 1  //
+            && splicep->driverIndex(0) == 0  //
+            && splicep->source(0)->dtypep()->isSame(splicep->dtypep())) {
+            const auto result = std::make_pair(splicep->source(0), splicep->driverFileLine(0));
+            VL_DO_DANGLING(splicep->unlinkDelete(*m_dfgp), splicep);
+            return result;
+        }
+        return {splicep, splicep->fileline()};
     }
 
     // VISITORS
@@ -593,6 +810,7 @@ class AstToDfgVisitor final : public VNVisitor {
             || nodep->varp()->isIfaceRef()  // Cannot handle interface references
             || nodep->varp()->delayp()  // Cannot handle delayed variables
             || nodep->classOrPackagep()  // Cannot represent cross module references
+            || nodep->varp()->isSc()  // SystemC variables are special and rare, we can ignore
         ) {
             markReferenced(nodep);
             m_foundUnhandled = true;
@@ -675,9 +893,32 @@ class AstToDfgVisitor final : public VNVisitor {
         iterate(&root);
         UASSERT_OBJ(m_uncommittedVertices.empty(), &root, "Uncommitted vertices remain");
 
-        // Canonicalize variables
-        canonicalizePacked();
-        canonicalizeArray();
+        if (dumpDfgLevel() >= 8) m_dfgp->dumpDotFilePrefixed(ctx.prefix() + "ast2dfg");
+
+        // Normalize variable drivers (remove multiple drivers, remove unnecessary splice vertices)
+        for (DfgVertexVar* const varp : m_dfgp->varVertices().unlinkable()) {
+            // Delete variables with no sinks nor sources (this can happen due to reverting
+            // uncommitted vertices, which does not remove variables)
+            if (!varp->hasSinks() && !varp->srcp()) {
+                VL_DO_DANGLING(varp->unlinkDelete(*m_dfgp), varp);
+                continue;
+            }
+
+            // Nothing to do for un-driven (input) variables
+            if (!varp->srcp()) continue;
+
+            // The driver of a variable must always be a splice vertex, normalize it
+            std::pair<DfgVertex*, FileLine*> normalizedDriver;
+            if (DfgSpliceArray* const sArrayp = varp->srcp()->cast<DfgSpliceArray>()) {
+                normalizedDriver = normalizeArray(varp, "", sArrayp);
+            } else if (DfgSplicePacked* const sPackedp = varp->srcp()->cast<DfgSplicePacked>()) {
+                normalizedDriver = normalizePacked(varp, "", sPackedp);
+            } else {
+                varp->v3fatalSrc("Unhandled DfgSplicePacked sub-type");  // LCOV_EXCL_LINE
+            }
+            varp->srcp(normalizedDriver.first);
+            varp->driverFileLine(normalizedDriver.second);
+        }
     }
 
 public:

src/V3DfgBreakCycles.cpp

@@ -20,6 +20,7 @@
 #include "V3DfgPasses.h"
 #include "V3Hash.h"
 
+#include <deque>
 #include <fstream>
 #include <limits>
 #include <unordered_map>
@@ -191,32 +192,56 @@ class TraceDriver final : public DfgVisitor {
     DfgGraph& m_dfg;  // The graph being processed
     // The strongly connected component we are trying to escape
     const uint32_t m_component;
+    const bool m_aggressive;  // Trace aggressively, creating intermediate ops
     uint32_t m_lsb = 0;  // LSB to extract from the currently visited Vertex
     uint32_t m_msb = 0;  // MSB to extract from the currently visited Vertex
     // Result of tracing the currently visited Vertex. Use SET_RESULT below!
     DfgVertex* m_resp = nullptr;
     std::vector<DfgVertex*> m_newVtxps;  // New vertices created during the traversal
-    std::ofstream m_lineCoverageFile;  // Line coverage file, just for testing
 
     std::vector<Visited> m_stack;  // Stack of currently visited vertices
     // Denotes if a 'Visited' entry appear in m_stack
     std::unordered_map<Visited, bool, Visited::Hash, Visited::Equal> m_visited;
 
+    std::ofstream m_lineCoverageFile;  // Line coverage file, just for testing
+
     // METHODS
 
-    // Create and return a new Vertex and add it to m_newVtxps. You should
+    // Create and return a new Vertex and add it to m_newVtxps. Fileline is
+    // taken from 'refp', but 'refp' is otherwise not used. You should
     // always use this to create new vertices, so unused ones (if a trace
     // eventually fails) can be cleaned up at the end.
     template <typename Vertex>
-    Vertex* make(FileLine* flp, uint32_t width) {
+    Vertex* make(const DfgVertex* refp, uint32_t width) {
         static_assert(std::is_base_of<DfgVertex, Vertex>::value  //
-                          && !std::is_base_of<DfgVertexVar, Vertex>::value  //
-                          && !std::is_same<DfgConst, DfgVertex>::value,
-                      "Should only make operation vertices");
-        AstNodeDType* const dtypep = DfgVertex::dtypeForWidth(width);
-        Vertex* const vtxp = new Vertex{m_dfg, flp, dtypep};
-        m_newVtxps.emplace_back(vtxp);
-        return vtxp;
+                          && !std::is_base_of<DfgVertexVar, Vertex>::value,
+                      "Should only make operation vertices and constants");
+
+        constexpr bool okWithoutAggressive =  //
+            std::is_same<DfgConst, Vertex>::value  //
+            || std::is_same<DfgSel, Vertex>::value  //
+            || std::is_same<DfgConcat, Vertex>::value  //
+            || std::is_same<DfgExtend, Vertex>::value;
+
+        UASSERT_OBJ(
+            okWithoutAggressive || m_aggressive, refp,
+            "Should only create Const, Sel, Concat, Exend Vertices without aggressive mode");
+
+        if VL_CONSTEXPR_CXX17 (std::is_same<DfgConst, Vertex>::value) {
+            DfgConst* const vtxp = new DfgConst{m_dfg, refp->fileline(), width};
+            m_newVtxps.emplace_back(vtxp);
+            return reinterpret_cast<Vertex*>(vtxp);
+        } else {
+            // TODO: this is a gross hack around lack of C++17 'if constexpr' Vtx is always Vertex
+            // when this code is actually executed, but needs a fudged type to type check when
+            // Vertex is DfgConst, in which case this code is unreachable ...
+            using Vtx = typename std::conditional<std::is_same<DfgConst, Vertex>::value, DfgSel,
+                                                  Vertex>::type;
+            AstNodeDType* const dtypep = DfgVertex::dtypeForWidth(width);
+            Vtx* const vtxp = new Vtx{m_dfg, refp->fileline(), dtypep};
+            m_newVtxps.emplace_back(vtxp);
+            return reinterpret_cast<Vertex*>(vtxp);
+        }
     }
 
     // Continue tracing drivers of the given vertex, at the given LSB. Every
@@ -256,7 +281,7 @@ class TraceDriver final : public DfgVisitor {
             // then we found what we were looking for.
             if (msb != vtxp->width() - 1 || lsb != 0) {
                 // Apply a Sel to extract the relevant bits if only a part is needed
-                DfgSel* const selp = make<DfgSel>(vtxp->fileline(), msb - lsb + 1);
+                DfgSel* const selp = make<DfgSel>(vtxp, msb - lsb + 1);
                 selp->fromp(vtxp);
                 selp->lsb(lsb);
                 m_resp = selp;
@@ -280,9 +305,49 @@ class TraceDriver final : public DfgVisitor {
         m_stack.pop_back();
 
         // Done
+        if (!m_resp) {
+            UINFO(9, "TraceDriver - Failed to trace vertex of type: " << vtxp->typeName());
+        }
         return m_resp;
     }
 
+    template <typename Vertex>
+    Vertex* bitwiseBinary(Vertex* vtxp) {
+        static_assert(std::is_base_of<DfgVertexBinary, Vertex>::value,
+                      "Should only call on DfgVertexBinary");
+        if (DfgVertex* const rp = trace(vtxp->rhsp(), m_msb, m_lsb)) {
+            if (DfgVertex* const lp = trace(vtxp->lhsp(), m_msb, m_lsb)) {
+                Vertex* const resp = make<Vertex>(vtxp, m_msb - m_lsb + 1);
+                resp->rhsp(rp);
+                resp->lhsp(lp);
+                return resp;
+            }
+        }
+        return nullptr;
+    }
+
+    // Predicate to do determine if vtxp[$bits(vtxp)-1:idx] is known to be zero
+    // Somewhat rudimentary but sufficient for current purposes.
+    static bool knownToBeZeroAtAndAbove(const DfgVertex* vtxp, uint32_t idx) {
+        if (const DfgConcat* const catp = vtxp->cast<DfgConcat>()) {
+            DfgConst* const lConstp = catp->lhsp()->cast<DfgConst>();
+            return lConstp && idx >= catp->rhsp()->width() && lConstp->isZero();
+        }
+        if (const DfgExtend* const extp = vtxp->cast<DfgExtend>()) {
+            return idx >= extp->srcp()->width();
+        }
+        return false;
+    }
+
+    // Like knownToBeZeroAtAndAbove, but checks vtxp[idx:0]
+    static bool knownToBeZeroAtAndBelow(const DfgVertex* vtxp, uint32_t idx) {
+        if (const DfgConcat* const catp = vtxp->cast<DfgConcat>()) {
+            DfgConst* const rConstp = catp->rhsp()->cast<DfgConst>();
+            return rConstp && idx < rConstp->width() && rConstp->isZero();
+        }
+        return false;
+    }
+
     // Use this macro to set the result in 'visit' methods. This also emits
     // a line to m_lineCoverageFile for testing.
     // TODO: Use C++20 std::source_location instead of a macro
@@ -298,7 +363,7 @@ class TraceDriver final : public DfgVisitor {
         UINFO(9, "TraceDriver - Unhandled vertex type: " << vtxp->typeName());
     }
 
-    void visit(DfgVarPacked* vtxp) override {
+    void visit(DfgSplicePacked* vtxp) override {
         // Proceed with the driver that wholly covers the searched bits
         const auto pair = vtxp->sourceEdges();
         for (size_t i = 0; i < pair.second; ++i) {
@@ -313,6 +378,34 @@ class TraceDriver final : public DfgVisitor {
         }
     }
 
+    void visit(DfgVarPacked* vtxp) override {
+        if (DfgVertex* const srcp = vtxp->srcp()) {
+            SET_RESULT(trace(srcp, m_msb, m_lsb));
+            return;
+        }
+    }
+
+    void visit(DfgArraySel* vtxp) override {
+        // Only constant select
+        DfgConst* const idxp = vtxp->bitp()->cast<DfgConst>();
+        if (!idxp) return;
+        // From a variable
+        DfgVarArray* varp = vtxp->fromp()->cast<DfgVarArray>();
+        if (!varp) return;
+        // Skip through intermediate variables
+        while (varp->srcp() && varp->srcp()->is<DfgVarArray>()) {
+            varp = varp->srcp()->as<DfgVarArray>();
+        }
+        // Find driver
+        if (!varp->srcp()) return;
+        DfgSpliceArray* const splicep = varp->srcp()->cast<DfgSpliceArray>();
+        if (!splicep) return;
+        DfgVertex* const driverp = splicep->driverAt(idxp->toSizeT());
+        if (!driverp) return;
+        // Trace the driver
+        SET_RESULT(trace(driverp, m_msb, m_lsb));
+    }
+
     void visit(DfgConcat* vtxp) override {
         DfgVertex* const rhsp = vtxp->rhsp();
         DfgVertex* const lhsp = vtxp->lhsp();
@@ -327,10 +420,10 @@ class TraceDriver final : public DfgVisitor {
             SET_RESULT(trace(lhsp, m_msb - rWidth, m_lsb - rWidth));
             return;
         }
-        // The traced bit span both sides, attempt to trace both
+        // The traced bit spans both sides, attempt to trace both
         if (DfgVertex* const rp = trace(rhsp, rWidth - 1, m_lsb)) {
             if (DfgVertex* const lp = trace(lhsp, m_msb - rWidth, 0)) {
-                DfgConcat* const resp = make<DfgConcat>(vtxp->fileline(), m_msb - m_lsb + 1);
+                DfgConcat* const resp = make<DfgConcat>(vtxp, m_msb - m_lsb + 1);
                 resp->rhsp(rp);
                 resp->lhsp(lp);
                 SET_RESULT(resp);
@@ -341,10 +434,24 @@ class TraceDriver final : public DfgVisitor {
 
     void visit(DfgExtend* vtxp) override {
         DfgVertex* const srcp = vtxp->srcp();
-        if (srcp->width() > m_msb) {
+        const uint32_t sWidth = srcp->width();
+        // If the traced bits are wholly in the input
+        if (sWidth > m_msb) {
             SET_RESULT(trace(srcp, m_msb, m_lsb));
             return;
         }
+        // If the traced bits are wholly in the extension
+        if (m_lsb >= sWidth) {
+            SET_RESULT(make<DfgConst>(vtxp, m_msb - m_lsb + 1));
+            return;
+        }
+        // The traced bits span both sides
+        if (DfgVertex* const sp = trace(srcp, sWidth - 1, m_lsb)) {
+            DfgExtend* const resp = make<DfgExtend>(vtxp, m_msb - m_lsb + 1);
+            resp->srcp(sp);
+            SET_RESULT(resp);
+            return;
+        }
     }
 
     void visit(DfgSel* vtxp) override {
@@ -353,12 +460,107 @@ class TraceDriver final : public DfgVisitor {
         return;
     }
 
+    void visit(DfgNot* vtxp) override {
+        if (!m_aggressive) return;
+        if (DfgVertex* const sp = trace(vtxp->srcp(), m_msb, m_lsb)) {
+            DfgNot* const resp = make<DfgNot>(vtxp, m_msb - m_lsb + 1);
+            resp->srcp(sp);
+            SET_RESULT(resp);
+            return;
+        }
+    }
+
+    void visit(DfgAnd* vtxp) override {
+        if (!m_aggressive) return;
+        SET_RESULT(bitwiseBinary(vtxp));
+    }
+    void visit(DfgOr* vtxp) override {
+        if (!m_aggressive) return;
+        SET_RESULT(bitwiseBinary(vtxp));
+    }
+    void visit(DfgXor* vtxp) override {
+        if (!m_aggressive) return;
+        SET_RESULT(bitwiseBinary(vtxp));
+    }
+
+    void visit(DfgShiftR* vtxp) override {
+        DfgVertex* const lhsp = vtxp->lhsp();
+        if (DfgConst* const rConstp = vtxp->rhsp()->cast<DfgConst>()) {
+            const uint32_t shiftAmnt = rConstp->toU32();
+            // Width of lower half of result
+            const uint32_t lowerWidth = shiftAmnt > vtxp->width() ? 0 : vtxp->width() - shiftAmnt;
+
+            // If the traced bits are wholly in the input
+            if (lowerWidth > m_msb) {
+                SET_RESULT(trace(lhsp, m_msb + shiftAmnt, m_lsb + shiftAmnt));
+                return;
+            }
+            // If the traced bits are wholly in the extension
+            if (m_lsb >= lowerWidth) {
+                SET_RESULT(make<DfgConst>(vtxp, m_msb - m_lsb + 1));
+                return;
+            }
+            // The traced bits span both sides
+            if (DfgVertex* const sp = trace(lhsp, lowerWidth - 1 + shiftAmnt, m_lsb + shiftAmnt)) {
+                DfgExtend* const resp = make<DfgExtend>(vtxp, m_msb - m_lsb + 1);
+                resp->srcp(sp);
+                SET_RESULT(resp);
+                return;
+            }
+            return;
+        }
+
+        // The shift amount is non-negative, so we can conclude zero if all
+        // bits at and above the LSB we seek are zeroes
+        if (knownToBeZeroAtAndAbove(lhsp, m_lsb)) {
+            SET_RESULT(make<DfgConst>(vtxp, m_msb - m_lsb + 1));
+            return;
+        }
+    }
+
+    void visit(DfgShiftL* vtxp) override {
+        DfgVertex* const lhsp = vtxp->lhsp();
+        if (DfgConst* const rConstp = vtxp->rhsp()->cast<DfgConst>()) {
+            const uint32_t shiftAmnt = rConstp->toU32();
+            // Width of lower half of result
+            const uint32_t lowerWidth = shiftAmnt > vtxp->width() ? vtxp->width() : shiftAmnt;
+
+            // If the traced bits are wholly in the input
+            if (m_lsb >= lowerWidth) {
+                SET_RESULT(trace(lhsp, m_msb - shiftAmnt, m_lsb - shiftAmnt));
+                return;
+            }
+            // If the traced bits are wholly in the extension
+            if (lowerWidth > m_msb) {
+                SET_RESULT(make<DfgConst>(vtxp, m_msb - m_lsb + 1));
+                return;
+            }
+            // The traced bits span both sides
+            if (DfgVertex* const sp = trace(lhsp, m_msb - shiftAmnt, lowerWidth - shiftAmnt)) {
+                DfgConcat* const resp = make<DfgConcat>(vtxp, m_msb - m_lsb + 1);
+                resp->rhsp(make<DfgConst>(vtxp, resp->width() - sp->width()));
+                resp->lhsp(sp);
+                SET_RESULT(resp);
+                return;
+            }
+            return;
+        }
+
+        // The shift amount is non-negative, so we can conclude zero if all
+        // bits at and below the MSB we seek are zeroes
+        if (knownToBeZeroAtAndBelow(lhsp, m_msb)) {
+            SET_RESULT(make<DfgConst>(vtxp, m_msb - m_lsb + 1));
+            return;
+        }
+    }
+
 #undef SET_RESULT
 
     // CONSTRUCTOR
-    TraceDriver(DfgGraph& dfg, uint32_t component)
+    TraceDriver(DfgGraph& dfg, uint32_t component, bool aggressive)
         : m_dfg{dfg}
-        , m_component{component} {
+        , m_component{component}
+        , m_aggressive{aggressive} {
         if (v3Global.opt.debugCheck()) {
             m_lineCoverageFile.open(  //
                 v3Global.opt.makeDir() + "/" + v3Global.opt.prefix()
@@ -371,9 +573,13 @@ public:
     // Given a Vertex that is part of an SCC denoted by vtxp->user<uint32_t>(),
     // return a vertex that is equivalent to 'vtxp[lsb +: width]', but is not
     // part of the same SCC. Returns nullptr if such a vertex cannot be
-    // computed. This can add new vertices to the graph.
-    static DfgVertex* apply(DfgGraph& dfg, DfgVertex* vtxp, uint32_t lsb, uint32_t width) {
-        TraceDriver traceDriver{dfg, vtxp->user<uint32_t>()};
+    // computed. This can add new vertices to the graph. The 'aggressive' flag
+    // enables creating many intermediate operations. This should only be set
+    // if it is reasonably certain the tracing will succeed, otherwise we can
+    // waste a lot of compute.
+    static DfgVertex* apply(DfgGraph& dfg, DfgVertex* vtxp, uint32_t lsb, uint32_t width,
+                            bool aggressive) {
+        TraceDriver traceDriver{dfg, vtxp->user<uint32_t>(), aggressive};
         // Find the out-of-component driver of the given vertex
         DfgVertex* const resultp = traceDriver.trace(vtxp, lsb + width - 1, lsb);
         // Delete unused newly created vertices (these can be created if a
@@ -393,6 +599,496 @@ public:
     }
 };
 
+class IndependentBits final : public DfgVisitor {
+    // STATE
+    const uint32_t m_component;  // The component the start vertex is part of
+    // Vertex to current bit mask map. The mask is set for the bits that **depend** on 'm_varp'.
+    std::unordered_map<const DfgVertex*, V3Number> m_vtxp2Mask;
+
+    std::ofstream m_lineCoverageFile;  // Line coverage file, just for testing
+
+    // METHODS
+    // Retrieve the mask for the given vertex (create it with value 0 if needed)
+    V3Number& mask(const DfgVertex* vtxp) {
+        // Look up (or create) mask for 'vtxp'
+        auto pair = m_vtxp2Mask.emplace(
+            std::piecewise_construct,  //
+            std::forward_as_tuple(vtxp),  //
+            std::forward_as_tuple(vtxp->fileline(), static_cast<int>(vtxp->width()), 0));
+        // Initialize to all ones if the vertex is part of the same component, otherwise zeroes
+        if (pair.second && vtxp->getUser<uint32_t>() == m_component) {
+            pair.first->second.setAllBits1();
+        }
+        return pair.first->second;
+    }
+
+    // Use this macro to call 'mask' in 'visit' methods. This also emits
+    // a line to m_lineCoverageFile for testing.
+    // TODO: Use C++20 std::source_location instead of a macro
+#define MASK(vtxp) \
+    ([this](const DfgVertex* p) -> V3Number& { \
+        if (VL_UNLIKELY(m_lineCoverageFile.is_open())) m_lineCoverageFile << __LINE__ << '\n'; \
+        return mask(p); \
+    }(vtxp))
+
+    // VISITORS
+    void visit(DfgVertex* vtxp) override {
+        UINFO(9, "Unhandled vertex type " << vtxp->typeName());
+        // Conservative assumption about all bits being dependent prevails
+    }
+
+    void visit(DfgSplicePacked* vtxp) override {
+        // Combine the masks of all drivers
+        V3Number& m = MASK(vtxp);
+        vtxp->forEachSourceEdge([&](DfgEdge& edge, size_t i) {
+            const DfgVertex* const srcp = edge.sourcep();
+            m.opSelInto(MASK(srcp), vtxp->driverLsb(i), srcp->width());
+        });
+    }
+
+    void visit(DfgVarPacked* vtxp) override {
+        if (DfgVertex* const srcp = vtxp->srcp()) MASK(vtxp) = MASK(srcp);
+    }
+
+    void visit(DfgArraySel* vtxp) override {
+        // Only constant select
+        DfgConst* const idxp = vtxp->bitp()->cast<DfgConst>();
+        if (!idxp) return;
+        // From a variable
+        DfgVarArray* varp = vtxp->fromp()->cast<DfgVarArray>();
+        if (!varp) return;
+        // Skip through intermediate variables
+        while (varp->srcp() && varp->srcp()->is<DfgVarArray>()) {
+            varp = varp->srcp()->as<DfgVarArray>();
+        }
+        // Find driver
+        if (!varp->srcp()) return;
+        DfgSpliceArray* const splicep = varp->srcp()->cast<DfgSpliceArray>();
+        if (!splicep) return;
+        DfgVertex* const driverp = splicep->driverAt(idxp->toSizeT());
+        if (!driverp) return;
+        // Update mask
+        MASK(vtxp) = MASK(driverp);
+    }
+
+    void visit(DfgConcat* vtxp) override {
+        const DfgVertex* const rhsp = vtxp->rhsp();
+        const DfgVertex* const lhsp = vtxp->lhsp();
+        V3Number& m = MASK(vtxp);
+        m.opSelInto(MASK(rhsp), 0, rhsp->width());
+        m.opSelInto(MASK(lhsp), rhsp->width(), lhsp->width());
+    }
+
+    void visit(DfgReplicate* vtxp) override {
+        const uint32_t count = vtxp->countp()->as<DfgConst>()->toU32();
+        const DfgVertex* const srcp = vtxp->srcp();
+        const uint32_t sWidth = srcp->width();
+        V3Number& vMask = MASK(vtxp);
+        V3Number& sMask = MASK(srcp);
+        for (uint32_t i = 0; i < count; ++i) vMask.opSelInto(sMask, i * sWidth, sWidth);
+    }
+
+    void visit(DfgSel* vtxp) override {
+        const uint32_t lsb = vtxp->lsb();
+        const uint32_t msb = lsb + vtxp->width() - 1;
+        MASK(vtxp).opSel(MASK(vtxp->fromp()), msb, lsb);
+    }
+
+    void visit(DfgExtend* vtxp) override {
+        const DfgVertex* const srcp = vtxp->srcp();
+        const uint32_t sWidth = srcp->width();
+        V3Number& m = MASK(vtxp);
+        m.opSelInto(MASK(srcp), 0, sWidth);
+        m.opSetRange(sWidth, vtxp->width() - sWidth, '0');
+    }
+
+    void visit(DfgNot* vtxp) override {  //
+        MASK(vtxp) = MASK(vtxp->srcp());
+    }
+
+    void visit(DfgAnd* vtxp) override {  //
+        MASK(vtxp).opOr(MASK(vtxp->lhsp()), MASK(vtxp->rhsp()));
+    }
+    void visit(DfgOr* vtxp) override {  //
+        MASK(vtxp).opOr(MASK(vtxp->lhsp()), MASK(vtxp->rhsp()));
+    }
+    void visit(DfgXor* vtxp) override {  //
+        MASK(vtxp).opOr(MASK(vtxp->lhsp()), MASK(vtxp->rhsp()));
+    }
+
+    void visit(DfgShiftR* vtxp) override {
+        DfgVertex* const rhsp = vtxp->rhsp();
+        DfgVertex* const lhsp = vtxp->lhsp();
+        const uint32_t width = vtxp->width();
+
+        // Constant shift can be computed precisely
+        if (DfgConst* const rConstp = rhsp->cast<DfgConst>()) {
+            const uint32_t shiftAmount = rConstp->toU32();
+            if (shiftAmount >= width) return;
+            V3Number shiftedMask{lhsp->fileline(), static_cast<int>(width), 0};
+            shiftedMask.opShiftR(MASK(lhsp), rConstp->num());
+            V3Number& m = MASK(vtxp);
+            m.opSelInto(shiftedMask, 0, width - shiftAmount);
+            m.opSetRange(width - shiftAmount, shiftAmount, '0');
+            return;
+        }
+
+        // Otherwise, as the shift amount is non-negative, any bit at or below
+        // the most significant dependent bit might be dependent
+        V3Number& lMask = MASK(lhsp);
+        V3Number& vMask = MASK(vtxp);
+        uint32_t lzc = 0;  // Leading zero count
+        while (lzc < width && lMask.bitIs0(width - 1 - lzc)) ++lzc;
+        while (lzc > 0) vMask.setBit(width - 1 - (--lzc), '0');
+    }
+
+    void visit(DfgShiftL* vtxp) override {
+        DfgVertex* const rhsp = vtxp->rhsp();
+        DfgVertex* const lhsp = vtxp->lhsp();
+        const uint32_t width = vtxp->width();
+
+        // Constant shift can be computed precisely
+        if (DfgConst* const rConstp = rhsp->cast<DfgConst>()) {
+            const uint32_t shiftAmount = rConstp->toU32();
+            if (shiftAmount >= width) return;
+            V3Number shiftedMask{lhsp->fileline(), static_cast<int>(width), 0};
+            shiftedMask.opShiftL(MASK(lhsp), rConstp->num());
+            V3Number& m = MASK(vtxp);
+            m.opSelInto(shiftedMask, shiftAmount, width - shiftAmount);
+            m.opSetRange(0, shiftAmount, '0');
+            return;
+        }
+
+        // Otherwise, as the shift amount is non-negative, any bit at or above
+        // the least significant dependent bit might be dependent
+        V3Number& lMask = MASK(lhsp);
+        V3Number& vMask = MASK(vtxp);
+        uint32_t tzc = 0;  // Trailing zero count
+        while (tzc < width && lMask.bitIs0(tzc)) ++tzc;
+        while (tzc > 0) vMask.setBit(--tzc, '0');
+    }
+
+#undef MASK
+
+    // CONSTRUCTOR
+    IndependentBits(DfgGraph& dfg, DfgVertex* vtxp)
+        : m_component{vtxp->getUser<uint32_t>()} {
+        if (v3Global.opt.debugCheck()) {
+            m_lineCoverageFile.open(  //
+                v3Global.opt.makeDir() + "/" + v3Global.opt.prefix()
+                    + "__V3DfgBreakCycles-IndependentBits-line-coverage.txt",  //
+                std::ios_base::out | std::ios_base::app);
+        }
+
+        // Work list for the traversal
+        std::deque<DfgVertex*> workList;
+
+        // Enqueue every operation vertex in the analysed component
+        for (DfgVertex& vtx : dfg.opVertices()) {
+            if (vtx.getUser<uint32_t>() == m_component) workList.emplace_back(&vtx);
+        }
+
+        // While there is an item on the worklist ...
+        while (!workList.empty()) {
+            // Grab next item
+            DfgVertex* const currp = workList.front();
+            workList.pop_front();
+
+            if (VN_IS(currp->dtypep(), UnpackArrayDType)) {
+                // For an unpacked array vertex, just enque it's sinks.
+                // (There can be no loops through arrays directly)
+                currp->forEachSink([&](DfgVertex& vtx) { workList.emplace_back(&vtx); });
+                continue;
+            }
+
+            // Grab current mask of item
+            const V3Number& maskCurr = mask(currp);
+            // Remember current mask
+            const V3Number prevMask = maskCurr;
+
+            // Dispatch
+            iterate(currp);
+
+            // If mask changed, enqueue sinks
+            if (!prevMask.isCaseEq(maskCurr)) {
+                currp->forEachSink([&](DfgVertex& vtx) { workList.emplace_back(&vtx); });
+
+                // Check the mask only ever contrects (no bit goes 0 -> 1)
+                if (VL_UNLIKELY(v3Global.opt.debugCheck())) {
+                    V3Number notPrev{prevMask};
+                    notPrev.opNot(prevMask);
+                    V3Number notPrevAndCurr{maskCurr};
+                    notPrevAndCurr.opAnd(notPrev, maskCurr);
+                    UASSERT_OBJ(notPrevAndCurr.isEqZero(), currp, "Mask should only contract");
+                }
+            }
+        }
+    }
+
+public:
+    // Given a Vertex that is part of an SCC denoted by vtxp->user<uint32_t>(),
+    // compute which bits of this vertex have a value that is independent of
+    // the current value of the Vertex itself (simple forward dataflow
+    // analysis). Returns a bit mask where a set bit indicates that bit is
+    // independent of the vertex itself (logic is not circular). The result is
+    // a conservative estimate, so bits reported dependent might not actually
+    // be, but all bits reported independent are known to be so.
+    static V3Number apply(DfgGraph& dfg, DfgVertex* vtxp) {
+        IndependentBits independentBits{dfg, vtxp};
+        // The mask represents the dependent bits, so invert it
+        V3Number result{vtxp->fileline(), static_cast<int>(vtxp->width()), 0};
+        result.opNot(independentBits.mask(vtxp));
+        return result;
+    }
+};
+
+class FixUpSelDrivers final {
+    static size_t fixUpSelSinks(DfgGraph& dfg, DfgVertex* vtxp) {
+        size_t nImprovements = 0;
+        const uint32_t component = vtxp->getUser<uint32_t>();
+        vtxp->forEachSink([&](DfgVertex& sink) {
+            // Ignore if sink is not part of same cycle
+            if (sink.getUser<uint32_t>() != component) return;
+            // Only handle Sel
+            DfgSel* const selp = sink.cast<DfgSel>();
+            if (!selp) return;
+            // Try to find of the driver of the selected bits outside the cycle
+            DfgVertex* const fixp
+                = TraceDriver::apply(dfg, vtxp, selp->lsb(), selp->width(), false);
+            if (!fixp) return;
+            // Found an out-of-cycle driver. We can replace this sel with that.
+            selp->replaceWith(fixp);
+            selp->unlinkDelete(dfg);
+            ++nImprovements;
+        });
+        return nImprovements;
+    }
+
+    static size_t fixUpArraySelSinks(DfgGraph& dfg, DfgVertex* vtxp) {
+        size_t nImprovements = 0;
+        const uint32_t component = vtxp->getUser<uint32_t>();
+        vtxp->forEachSink([&](DfgVertex& sink) {
+            // Ignore if sink is not part of same cycle
+            if (sink.getUser<uint32_t>() != component) return;
+            // Only handle ArraySels
+            DfgArraySel* const aselp = sink.cast<DfgArraySel>();
+            if (!aselp) return;
+            // First, try to fix up the whole word
+            DfgVertex* const fixp = TraceDriver::apply(dfg, aselp, 0, aselp->width(), false);
+            if (fixp) {
+                // Found an out-of-cycle driver for the whole ArraySel
+                aselp->replaceWith(fixp);
+                aselp->unlinkDelete(dfg);
+                ++nImprovements;
+            } else {
+                // Attempt to fix up piece-wise at Sels applied to the ArraySel
+                nImprovements += fixUpSelSinks(dfg, aselp);
+                // Remove if became unused
+                if (!aselp->hasSinks()) aselp->unlinkDelete(dfg);
+            }
+        });
+        return nImprovements;
+    }
+
+public:
+    // Attempt to push Sel form Var through to the driving
+    // expression of the selected bits. This can fix things like
+    // 'a[1:0] = foo', 'a[2] = a[1]', which are somewhat common.
+    // Returns the number of drivers fixed up.
+    static size_t apply(DfgGraph& dfg, DfgVertexVar* varp) {
+        UINFO(9, "FixUpSelDrivers of " << varp->nodep()->name());
+        size_t nImprovements = 0;
+        if (varp->is<DfgVarPacked>()) {
+            // For Packed variables, fix up all Sels applied to it
+            nImprovements += fixUpSelSinks(dfg, varp);
+        } else if (varp->is<DfgVarArray>()) {
+            // For Array variables, fix up each ArraySel applied to it
+            nImprovements += fixUpArraySelSinks(dfg, varp);
+        }
+        UINFO(9, "FixUpSelDrivers made " << nImprovements << " improvements");
+        return nImprovements;
+    }
+};
+
+class FixUpIndependentRanges final {
+    // Returns a bitmask set if that bit of 'vtxp' is used (has a sink)
+    static V3Number computeUsedBits(DfgVertex* vtxp) {
+        V3Number result{vtxp->fileline(), static_cast<int>(vtxp->width()), 0};
+        vtxp->forEachSink([&result](DfgVertex& sink) {
+            // If used via a Sel, mark the selected bits used
+            if (DfgSel* const selp = sink.cast<DfgSel>()) {
+                uint32_t lsb = selp->lsb();
+                uint32_t msb = lsb + selp->width() - 1;
+                for (uint32_t i = lsb; i <= msb; ++i) result.setBit(i, '1');
+                return;
+            }
+            // Used without a Sel, so all bits are used
+            result.setAllBits1();
+        });
+        return result;
+    }
+
+    static std::string debugStr(DfgVertex* vtxp) {
+        if (DfgArraySel* const aselp = vtxp->cast<DfgArraySel>()) {
+            const size_t i = aselp->bitp()->as<DfgConst>()->toSizeT();
+            return debugStr(aselp->fromp()) + "[" + std::to_string(i) + "]";
+        }
+        if (DfgVertexVar* const varp = vtxp->cast<DfgVertexVar>()) {
+            return varp->nodep()->name();
+        }
+        vtxp->v3fatalSrc("Unhandled node type");  // LCOV_EXCL_LINE
+    }
+
+    // Trace drivers of independent bits of 'vtxp' in the range '[hi:lo]'
+    // append replacement terms to 'termps'. Returns number of successful
+    // replacements.
+    static size_t gatherTerms(std::vector<DfgVertex*>& termps, DfgGraph& dfg,
+                              DfgVertex* const vtxp, const V3Number& indpBits, const uint32_t hi,
+                              const uint32_t lo) {
+        size_t nImprovements = 0;
+        // Iterate through consecutive dependent/non-dependet ranges within [hi:lo]
+        bool isIndependent = indpBits.bitIs1(lo);
+        uint32_t lsb = lo;
+        for (uint32_t msb = lo; msb <= hi; ++msb) {
+            const bool endRange = msb == hi || isIndependent != indpBits.bitIs1(msb + 1);
+            if (!endRange) continue;
+            const uint32_t width = msb - lsb + 1;
+            DfgVertex* termp = nullptr;
+            // If the range is not self-dependent, attempt to trace its driver
+            if (isIndependent) {
+                termp = TraceDriver::apply(dfg, vtxp, lsb, width, true);
+                if (termp) {
+                    ++nImprovements;
+                } else {
+                    UINFO(5, "TraceDriver of independent range failed for "
+                                 << debugStr(vtxp) << "[" << msb << ":" << lsb << "]");
+                }
+            }
+            // Fall back on using the part of the variable (if dependent, or trace failed)
+            if (!termp) {
+                AstNodeDType* const dtypep = DfgVertex::dtypeForWidth(width);
+                DfgSel* const selp = new DfgSel{dfg, vtxp->fileline(), dtypep};
+                // Do not connect selp->fromp yet, need to do afer replacing 'vtxp'
+                selp->lsb(lsb);
+                termp = selp;
+            }
+            // Record the term
+            termps.emplace_back(termp);
+            // Next iteration
+            isIndependent = !isIndependent;
+            lsb = msb + 1;
+        }
+        return nImprovements;
+    }
+
+    static size_t fixUpPacked(DfgGraph& dfg, DfgVertex* vtxp) {
+        UASSERT_OBJ(VN_IS(vtxp->dtypep(), BasicDType), vtxp, "Should be a packed BasicDType");
+        size_t nImprovements = 0;
+
+        // Figure out which bits of 'vtxp' are used
+        const V3Number usedBits = computeUsedBits(vtxp);
+        UINFO(9, "Used        bits of '" << debugStr(vtxp) << "' are "
+                                         << usedBits.displayed(vtxp->fileline(), "%b"));
+        // Nothing to do if no bits are used
+        if (usedBits.isEqZero()) return 0;
+
+        // Figure out which bits of 'vtxp' are dependent of themselves
+        const V3Number indpBits = IndependentBits::apply(dfg, vtxp);
+        UINFO(9, "Independent bits of '" << debugStr(vtxp) << "' are "
+                                         << indpBits.displayed(vtxp->fileline(), "%b"));
+        // Can't do anything if all bits are dependent
+        if (indpBits.isEqZero()) return 0;
+
+        {
+            // Nothing to do if no used bits are independen (all used bits are dependent)
+            V3Number usedAndIndependent{vtxp->fileline(), static_cast<int>(vtxp->width()), 0};
+            usedAndIndependent.opAnd(usedBits, indpBits);
+            if (usedAndIndependent.isEqZero()) return 0;
+        }
+
+        // We are computing the terms to concatenate and replace 'vtxp' with
+        std::vector<DfgVertex*> termps;
+
+        // Iterate through consecutive used/unused ranges
+        FileLine* const flp = vtxp->fileline();
+        const uint32_t width = vtxp->width();
+        bool isUsed = usedBits.bitIs1(0);  // Is current range used
+        uint32_t lsb = 0;  // LSB of current range
+        for (uint32_t msb = 0; msb < width; ++msb) {
+            const bool endRange = msb == width - 1 || isUsed != usedBits.bitIs1(msb + 1);
+            if (!endRange) continue;
+            if (isUsed) {
+                // The range is used, compute the replacement terms
+                nImprovements += gatherTerms(termps, dfg, vtxp, indpBits, msb, lsb);
+            } else {
+                // The range is not used, just use constant 0 as a placeholder
+                termps.emplace_back(new DfgConst{dfg, flp, msb - lsb + 1});
+            }
+            // Next iteration
+            isUsed = !isUsed;
+            lsb = msb + 1;
+        }
+
+        // If we managed to imporove something, apply the replacement
+        if (nImprovements) {
+            // Concatenate all the terms to create the replacement
+            DfgVertex* replacementp = termps.front();
+            for (size_t i = 1; i < termps.size(); ++i) {
+                DfgVertex* const termp = termps[i];
+                const uint32_t catWidth = replacementp->width() + termp->width();
+                AstNodeDType* const dtypep = DfgVertex::dtypeForWidth(catWidth);
+                DfgConcat* const catp = new DfgConcat{dfg, flp, dtypep};
+                catp->rhsp(replacementp);
+                catp->lhsp(termp);
+                replacementp = catp;
+            }
+
+            // Replace the vertex
+            vtxp->replaceWith(replacementp);
+            // Connect the Sel nodes in the replacement
+            for (DfgVertex* const termp : termps) {
+                if (DfgSel* const selp = termp->cast<DfgSel>()) {
+                    if (!selp->fromp()) selp->fromp(vtxp);
+                }
+            }
+        }
+
+        return nImprovements;
+    }
+
+public:
+    // Similar to FixUpSelDrivers, but first comptute which bits of the
+    // variable are self dependent, and fix up those that are independent
+    // but used.
+    static size_t apply(DfgGraph& dfg, DfgVertexVar* varp) {
+        UINFO(9, "FixUpIndependentRanges of " << varp->nodep()->name());
+        size_t nImprovements = 0;
+
+        if (varp->is<DfgVarPacked>()) {
+            // For Packed variables, fix up as whole
+            nImprovements += fixUpPacked(dfg, varp);
+        } else if (varp->is<DfgVarArray>()) {
+            // For array variables, fix up element-wise
+            const uint32_t component = varp->getUser<uint32_t>();
+            varp->forEachSink([&](DfgVertex& sink) {
+                // Ignore if sink is not part of cycle
+                if (sink.getUser<uint32_t>() != component) return;
+                // Only handle ArraySels with constant index
+                DfgArraySel* const aselp = sink.cast<DfgArraySel>();
+                if (!aselp) return;
+                if (!aselp->bitp()->is<DfgConst>()) return;
+                // Fix up the word
+                nImprovements += fixUpPacked(dfg, aselp);
+                // Remove if became unused
+                if (!aselp->hasSinks()) aselp->unlinkDelete(dfg);
+            });
+        }
+
+        UINFO(9, "FixUpIndependentRanges made " << nImprovements << " improvements");
+        return nImprovements;
+    }
+};
+
 std::pair<std::unique_ptr<DfgGraph>, bool>
 V3DfgPasses::breakCycles(const DfgGraph& dfg, V3DfgOptimizationContext& ctx) {
     // Shorthand for dumping graph at given dump level
@@ -441,35 +1137,35 @@ V3DfgPasses::breakCycles(const DfgGraph& dfg, V3DfgOptimizationContext& ctx) {
         UINFO(9, "New iteration after " << nImprovements << " improvements");
         prevNImprovements = nImprovements;
 
-        // Method 1. Attempt to push Sel form Var through to the driving
-        // expression of the selected bits. This can fix things like
-        // 'a[1:0] = foo', 'a[2] = a[1]', which are somewhat common.
+        // Method 1: FixUpSelDrivers
         for (DfgVertexVar& vtx : res.varVertices()) {
-            // Only handle DfgVarPacked at this point
-            DfgVarPacked* const varp = vtx.cast<DfgVarPacked>();
-            if (!varp) continue;
             // If Variable is not part of a cycle, move on
-            const uint32_t component = varp->getUser<uint32_t>();
+            const uint32_t component = vtx.getUser<uint32_t>();
             if (!component) continue;
 
-            UINFO(9, "Attempting to TraceDriver " << varp->nodep()->name());
+            const size_t nFixed = FixUpSelDrivers::apply(res, &vtx);
+            if (nFixed) {
+                nImprovements += nFixed;
+                ctx.m_breakCyclesContext.m_nImprovements += nFixed;
+                dump(9, res, "FixUpSelDrivers");
+            }
+        }
 
-            varp->forEachSink([&](DfgVertex& sink) {
-                // Ignore if sink is not part of cycle
-                if (sink.getUser<uint32_t>() != component) return;
-                // Only Handle Sels now
-                DfgSel* const selp = sink.cast<DfgSel>();
-                if (!selp) return;
-                // Try to find of the driver of the selected bits outside the cycle
-                DfgVertex* const fixp = TraceDriver::apply(res, varp, selp->lsb(), selp->width());
-                if (!fixp) return;
-                // Found an out-of-cycle driver. We can replace this sel with that.
-                selp->replaceWith(fixp);
-                selp->unlinkDelete(res);
-                ++nImprovements;
-                ++ctx.m_breakCyclesContext.m_nImprovements;
-                dump(9, res, "TraceDriver");
-            });
+        // If we managed to fix something, try again with the earlier methods
+        if (nImprovements != prevNImprovements) continue;
+
+        // Method 2. FixUpIndependentRanges
+        for (DfgVertexVar& vtx : res.varVertices()) {
+            // If Variable is not part of a cycle, move on
+            const uint32_t component = vtx.getUser<uint32_t>();
+            if (!component) continue;
+
+            const size_t nFixed = FixUpIndependentRanges::apply(res, &vtx);
+            if (nFixed) {
+                nImprovements += nFixed;
+                ctx.m_breakCyclesContext.m_nImprovements += nFixed;
+                dump(9, res, "FixUpIndependentRanges");
+            }
         }
     } while (nImprovements != prevNImprovements);
 

src/V3DfgDecomposition.cpp

@@ -341,32 +341,20 @@ class ExtractCyclicComponents final {
         return *clonep;
     }
 
-    // Fix up non-variable sources of a DfgVertexVar that are in a different component,
-    // using the provided 'relink' callback
-    template <typename T_Vertex>
-    void fixSources(T_Vertex& vtx, std::function<void(T_Vertex&, DfgVertex&, size_t)> relink) {
-        static_assert(std::is_base_of<DfgVertexVar, T_Vertex>::value,
-                      "'Vertex' must be a 'DfgVertexVar'");
+    // Fix edges that cross components
+    void fixEdges(DfgVertexVar& vtx) {
         const size_t component = state(vtx).component;
-        vtx.forEachSourceEdge([&](DfgEdge& edge, size_t idx) {
-            DfgVertex& source = *edge.sourcep();
-            // DfgVertexVar sources are fixed up by `fixSinks` on those sources
-            if (source.is<DfgVertexVar>()) return;
-            const size_t sourceComponent = state(source).component;
-            // Same component is OK
-            if (sourceComponent == component) return;
-            // Unlink the source edge (source is reconnected by 'relink'
-            edge.unlinkSource();
-            // Apply the fixup
-            // cppcheck-has-bug-suppress constVariable
-            DfgVertexVar& clone = getClone(vtx, sourceComponent);
-            relink(*(clone.as<T_Vertex>()), source, idx);
-        });
-    }
 
-    // Fix up sinks of given variable vertex that are in a different component
-    void fixSinks(DfgVertexVar& vtx) {
-        const size_t component = state(vtx).component;
+        // All variable vertices have at most a single source, and only variable
+        // vertices can have multiple sinks, therefore the source must be either:
+        // - in the same component as the variable vertex
+        // - be a variable vertex itself, which might be in a different component
+        // The later case will be fixed up when handling the source variable
+        DfgVertex* const srcp = vtx.srcp();
+        UASSERT_OBJ(!srcp || srcp->is<DfgVertexVar>() || state(*srcp).component == component, &vtx,
+                    "Driver of DfgVertexVar must be in the same component");
+
+        // Fix up sinks in a differetn component
         vtx.forEachSinkEdge([&](DfgEdge& edge) {
             const size_t sinkComponent = state(*edge.sinkp()).component;
             // Same component is OK
@@ -376,49 +364,6 @@ class ExtractCyclicComponents final {
         });
     }
 
-    // Fix edges that cross components
-    void fixEdges(DfgVertexVar& vtx) {
-        if (DfgVarPacked* const vvtxp = vtx.cast<DfgVarPacked>()) {
-            fixSources<DfgVarPacked>(
-                *vvtxp, [&](DfgVarPacked& clone, DfgVertex& driver, size_t driverIdx) {
-                    clone.addDriver(vvtxp->driverFileLine(driverIdx),  //
-                                    vvtxp->driverLsb(driverIdx), &driver);
-                });
-            fixSinks(*vvtxp);
-            return;
-        }
-
-        if (DfgVarArray* const vvtxp = vtx.cast<DfgVarArray>()) {
-            fixSources<DfgVarArray>(  //
-                *vvtxp, [&](DfgVarArray& clone, DfgVertex& driver, size_t driverIdx) {
-                    clone.addDriver(vvtxp->driverFileLine(driverIdx),  //
-                                    vvtxp->driverIndex(driverIdx), &driver);
-                });
-            fixSinks(*vvtxp);
-            return;
-        }
-    }
-
-    static void packSources(DfgGraph& dfg) {
-        // Remove undriven variable sources
-        for (DfgVertexVar* const vtxp : dfg.varVertices().unlinkable()) {
-            if (DfgVarPacked* const varp = vtxp->cast<DfgVarPacked>()) {
-                varp->packSources();
-                if (!varp->hasSinks() && varp->arity() == 0) {
-                    VL_DO_DANGLING(varp->unlinkDelete(dfg), varp);
-                }
-                continue;
-            }
-            if (DfgVarArray* const varp = vtxp->cast<DfgVarArray>()) {
-                varp->packSources();
-                if (!varp->hasSinks() && varp->arity() == 0) {
-                    VL_DO_DANGLING(varp->unlinkDelete(dfg), varp);
-                }
-                continue;
-            }
-        }
-    }
-
     template <typename Vertex>
     void moveVertices(DfgVertex::List<Vertex>& list) {
         for (DfgVertex* const vtxp : list.unlinkable()) {
@@ -446,11 +391,6 @@ class ExtractCyclicComponents final {
                 UASSERT_OBJ(component == state(snk).component, &vtx,
                             "Edge crossing components without variable involvement");
             });
-            if (const DfgVertexVar* const vtxp = vtx.cast<DfgVertexVar>()) {
-                vtxp->forEachSourceEdge([](const DfgEdge& edge, size_t) {
-                    UASSERT_OBJ(edge.sourcep(), edge.sinkp(), "Missing source on variable vertex");
-                });
-            }
         });
     }
 
@@ -489,11 +429,6 @@ class ExtractCyclicComponents final {
             if (&vtx == lastp) break;
         }
 
-        // Pack sources of variables to remove the now undriven inputs
-        // (cloning might have unlinked some of the inputs),
-        packSources(m_dfg);
-        for (const auto& dfgp : m_components) packSources(*dfgp);
-
         // Check results for consistency
         if (VL_UNLIKELY(m_doExpensiveChecks)) {
             checkEdges(m_dfg);

src/V3DfgDfgToAst.cpp

@@ -188,58 +188,57 @@ class DfgToAstVisitor final : DfgVisitor {
         return resultp;
     }
 
-    void addResultEquation(const DfgVertexVar* vtxp, FileLine* flp, AstNodeExpr* lhsp,
-                           AstNodeExpr* rhsp) {
-        AstAssignW* const assignp = new AstAssignW{flp, lhsp, rhsp};
-        if VL_CONSTEXPR_CXX17 (T_Scoped) {
-            // Add it to the scope holding the target variable
-            getCombActive(vtxp->varScopep()->scopep())->addStmtsp(assignp);
-        } else {
-            // Add it to the parend module of the DfgGraph
-            m_modp->addStmtsp(assignp);
+    void convertDriver(AstScope* scopep, FileLine* flp, AstNodeExpr* lhsp, DfgVertex* driverp) {
+        if (!driverp->is<DfgVertexSplice>()) {
+            // Base case: assign vertex to current lhs
+            AstNodeExpr* const rhsp = convertDfgVertexToAstNodeExpr(driverp);
+            AstAssignW* const assignp = new AstAssignW{flp, lhsp, rhsp};
+            lhsp->foreach([flp](AstNode* nodep) { nodep->fileline(flp); });
+            if VL_CONSTEXPR_CXX17 (T_Scoped) {
+                // Add it to the scope holding the target variable
+                getCombActive(scopep)->addStmtsp(assignp);
+            } else {
+                // Add it to the parend module of the DfgGraph
+                m_modp->addStmtsp(assignp);
+            }
+            ++m_ctx.m_resultEquations;
+            return;
         }
-        ++m_ctx.m_resultEquations;
-    }
 
-    void convertVarDriver(const DfgVarPacked* dfgVarp) {
-        if (dfgVarp->isDrivenFullyByDfg()) {
-            // Whole variable is driven. Render driver and assign directly to whole variable.
-            FileLine* const flp = dfgVarp->driverFileLine(0);
-            AstVarRef* const lhsp = new AstVarRef{flp, getNode(dfgVarp), VAccess::WRITE};
-            AstNodeExpr* const rhsp = convertDfgVertexToAstNodeExpr(dfgVarp->source(0));
-            addResultEquation(dfgVarp, flp, lhsp, rhsp);
-        } else {
-            // Variable is driven partially. Render each driver as a separate assignment.
-            dfgVarp->forEachSourceEdge([&](const DfgEdge& edge, size_t idx) {
-                UASSERT_OBJ(edge.sourcep(), dfgVarp, "Should have removed undriven sources");
-                // Render the rhs expression
-                AstNodeExpr* const rhsp = convertDfgVertexToAstNodeExpr(edge.sourcep());
-                // Create select LValue
-                FileLine* const flp = dfgVarp->driverFileLine(idx);
-                AstVarRef* const refp = new AstVarRef{flp, getNode(dfgVarp), VAccess::WRITE};
-                AstConst* const lsbp = new AstConst{flp, dfgVarp->driverLsb(idx)};
+        if (DfgSplicePacked* const sPackedp = driverp->cast<DfgSplicePacked>()) {
+            // Partial assignment of packed value
+            sPackedp->forEachSourceEdge([&](const DfgEdge& edge, size_t i) {
+                UASSERT_OBJ(edge.sourcep(), sPackedp, "Should have removed undriven sources");
+                // Create Sel
+                FileLine* const dflp = sPackedp->driverFileLine(i);
+                AstConst* const lsbp = new AstConst{dflp, sPackedp->driverLsb(i)};
                 const int width = static_cast<int>(edge.sourcep()->width());
-                AstSel* const lhsp = new AstSel{flp, refp, lsbp, width};
-                // Add assignment of the value to the selected bits
-                addResultEquation(dfgVarp, flp, lhsp, rhsp);
+                AstSel* const nLhsp = new AstSel{dflp, lhsp->cloneTreePure(false), lsbp, width};
+                // Convert source
+                convertDriver(scopep, dflp, nLhsp, edge.sourcep());
+                // Delete Sel if not consumed
+                if (!nLhsp->backp()) VL_DO_DANGLING(nLhsp->deleteTree(), nLhsp);
             });
+            return;
         }
-    }
 
-    void convertArrayDiver(const DfgVarArray* dfgVarp) {
-        // Variable is driven partially. Assign from parts of the canonical var.
-        dfgVarp->forEachSourceEdge([&](const DfgEdge& edge, size_t idx) {
-            UASSERT_OBJ(edge.sourcep(), dfgVarp, "Should have removed undriven sources");
-            // Render the rhs expression
-            AstNodeExpr* const rhsp = convertDfgVertexToAstNodeExpr(edge.sourcep());
-            // Create select LValue
-            FileLine* const flp = dfgVarp->driverFileLine(idx);
-            AstVarRef* const refp = new AstVarRef{flp, getNode(dfgVarp), VAccess::WRITE};
-            AstConst* const idxp = new AstConst{flp, dfgVarp->driverIndex(idx)};
-            AstArraySel* const lhsp = new AstArraySel{flp, refp, idxp};
-            // Add assignment of the value to the selected bits
-            addResultEquation(dfgVarp, flp, lhsp, rhsp);
-        });
+        if (DfgSpliceArray* const sArrayp = driverp->cast<DfgSpliceArray>()) {
+            // Partial assignment of array variable
+            sArrayp->forEachSourceEdge([&](const DfgEdge& edge, size_t i) {
+                UASSERT_OBJ(edge.sourcep(), sArrayp, "Should have removed undriven sources");
+                // Create ArraySel
+                FileLine* const dflp = sArrayp->driverFileLine(i);
+                AstConst* const idxp = new AstConst{dflp, sArrayp->driverIndex(i)};
+                AstArraySel* const nLhsp = new AstArraySel{dflp, lhsp->cloneTreePure(false), idxp};
+                // Convert source
+                convertDriver(scopep, dflp, nLhsp, edge.sourcep());
+                // Delete ArraySel if not consumed
+                if (!nLhsp->backp()) VL_DO_DANGLING(nLhsp->deleteTree(), nLhsp);
+            });
+            return;
+        }
+
+        driverp->v3fatalSrc("Unhandled DfgVertexSplice sub-type");  // LCOV_EXCL_LINE
     }
 
     // VISITORS
@@ -285,16 +284,15 @@ class DfgToAstVisitor final : DfgVisitor {
         // The graph must have been regularized, so we only need to render assignments
         for (DfgVertexVar& vtx : dfg.varVertices()) {
             // If there is no driver (this vertex is an input to the graph), then nothing to do.
-            if (!vtx.isDrivenByDfg()) continue;
+            if (!vtx.srcp()) continue;
 
-            // Render packed variable assignments
-            if (const DfgVarPacked* const dfgVarp = vtx.cast<DfgVarPacked>()) {
-                convertVarDriver(dfgVarp);
-                continue;
-            }
-
-            // Render array variable assignments
-            convertArrayDiver(vtx.as<DfgVarArray>());
+            // Render variable assignments
+            FileLine* const flp = vtx.driverFileLine() ? vtx.driverFileLine() : vtx.fileline();
+            AstScope* const scopep = T_Scoped ? vtx.varScopep()->scopep() : nullptr;
+            AstVarRef* const lhsp = new AstVarRef{flp, getNode(&vtx), VAccess::WRITE};
+            convertDriver(scopep, flp, lhsp, vtx.srcp());
+            // convetDriver clones and might not use up the original lhsp
+            if (!lhsp->backp()) VL_DO_DANGLING(lhsp->deleteTree(), lhsp);
         }
     }
 

src/V3DfgPasses.cpp

@@ -169,18 +169,8 @@ void V3DfgPasses::cse(DfgGraph& dfg, V3DfgCseContext& ctx) {
 void V3DfgPasses::inlineVars(DfgGraph& dfg) {
     for (DfgVertexVar& vtx : dfg.varVertices()) {
         if (DfgVarPacked* const varp = vtx.cast<DfgVarPacked>()) {
-            // Don't inline SystemC variables, as SystemC types are not interchangeable with
-            // internal types, and hence the variables are not interchangeable either.
-            if (varp->hasSinks() && varp->isDrivenFullyByDfg() && !varp->varp()->isSc()) {
-                DfgVertex* const driverp = varp->source(0);
-
-                // We must keep the original driver in certain cases, when swapping them would
-                // not be functionally or technically (implementation reasons) equivalent:
-                // 1. If driven from a SystemC variable (assignment is non-trivial)
-                if (DfgVertexVar* const driverVarp = driverp->cast<DfgVarPacked>()) {
-                    if (driverVarp->varp()->isSc()) continue;
-                }
-
+            if (varp->hasSinks() && varp->isDrivenFullyByDfg()) {
+                DfgVertex* const driverp = varp->srcp();
                 varp->forEachSinkEdge([=](DfgEdge& edge) { edge.relinkSource(driverp); });
             }
         }
@@ -381,12 +371,14 @@ void V3DfgPasses::binToOneHot(DfgGraph& dfg, V3DfgBinToOneHotContext& ctx) {
         // The index variable
         DfgVarPacked* const idxVtxp = [&]() {
             // If there is an existing result variable, use that, otherwise create a new variable
-            DfgVarPacked* varp = srcp->getResultVar();
-            if (!varp) {
+            DfgVarPacked* varp = nullptr;
+            if (DfgVertexVar* const vp = srcp->getResultVar()) {
+                varp = vp->as<DfgVarPacked>();
+            } else {
                 const std::string name = dfg.makeUniqueName("BinToOneHot_Idx", nTables);
                 varp = dfg.makeNewVar(flp, name, idxDTypep, nullptr)->as<DfgVarPacked>();
                 varp->varp()->isInternal(true);
-                varp->addDriver(flp, 0, srcp);
+                varp->srcp(srcp);
             }
             varp->setHasModRefs();
             return varp;
@@ -554,12 +546,10 @@ void V3DfgPasses::eliminateVars(DfgGraph& dfg, V3DfgEliminateVarsContext& ctx) {
         if (!varp->hasModRefs()) {
             // If it is only referenced in this DFG, it can be removed
             ++ctx.m_varsRemoved;
-            varp->replaceWith(varp->source(0));
+            varp->replaceWith(varp->srcp());
             varp->nodep()->unlinkFrBack()->deleteTree();
-        } else if (DfgVarPacked* const driverp = varp->source(0)->cast<DfgVarPacked>()) {
-            // If it's driven from another variable, it can be replaced by that. However, we do not
-            // want to propagate SystemC variables into the design.
-            if (driverp->varp()->isSc()) continue;
+        } else if (DfgVarPacked* const driverp = varp->srcp()->cast<DfgVarPacked>()) {
+            // If it's driven from another variable, it can be replaced by that.
             // Mark it for replacement
             ++ctx.m_varsReplaced;
             UASSERT_OBJ(!varp->hasSinks(), varp, "Variable inlining should make this impossible");

src/V3DfgPeephole.cpp

@@ -1202,11 +1202,16 @@ class V3DfgPeephole final : public DfgVisitor {
     void visit(DfgArraySel* vtxp) override {
         if (DfgConst* const idxp = vtxp->bitp()->cast<DfgConst>()) {
             if (DfgVarArray* const varp = vtxp->fromp()->cast<DfgVarArray>()) {
-                const size_t idx = idxp->toSizeT();
-                if (DfgVertex* const driverp = varp->driverAt(idx)) {
-                    APPLYING(INLINE_ARRAYSEL) {
-                        replace(vtxp, driverp);
-                        return;
+                if (varp->srcp() && !varp->varp()->isForced()) {
+                    if (DfgSpliceArray* const splicep = varp->srcp()->cast<DfgSpliceArray>()) {
+                        if (DfgVertex* const driverp = splicep->driverAt(idxp->toSizeT())) {
+                            if (!driverp->is<DfgVertexSplice>()) {
+                                APPLYING(INLINE_ARRAYSEL) {
+                                    replace(vtxp, driverp);
+                                    return;
+                                }
+                            }
+                        }
                     }
                 }
             }

src/V3DfgRegularize.cpp

@@ -45,12 +45,15 @@ class DfgRegularize final {
         // Ensure intermediate values used multiple times are written to variables
         for (DfgVertex& vtx : m_dfg.opVertices()) {
             const bool needsIntermediateVariable = [&]() {
-                // Anything that drives an SC variable needs an intermediate,
-                // as we can only assign simple variables to SC variables at runtime.
-                const bool hasScSink = vtx.findSink<DfgVertexVar>([](const DfgVertexVar& var) {  //
-                    return var.varp()->isSc();
-                });
-                if (hasScSink) return true;
+                // Splice vertices represent partial assignments, so they need a variable
+                // iff and only if they have a non-variable sink.
+                if (vtx.is<DfgVertexSplice>()) {
+                    const bool hasNonVarSink
+                        = vtx.findSink<DfgVertex>([](const DfgVertex& snk) {  //
+                              return !snk.is<DfgVertexVar>() && !snk.is<DfgVertexSplice>();
+                          });
+                    return hasNonVarSink;
+                }
                 // Operations without multiple sinks need no variables
                 if (!vtx.hasMultipleSinks()) return false;
                 // Array selects need no variables, they are just memory references
@@ -63,26 +66,21 @@ class DfgRegularize final {
 
             // This is an op that requires a result variable. Ensure it is
             // assigned to one, and redirect other sinks read that variable.
-            if (DfgVarPacked* const varp = vtx.getResultVar()) {
-                // A variable already exists
-                UASSERT_OBJ(varp->arity() == 1, varp, "Result variable with multiple drivers");
-                FileLine* const flp = varp->driverFileLine(0);
-                varp->sourceEdge(0)->unlinkSource();
-                varp->resetSources();
+            if (DfgVertexVar* const varp = vtx.getResultVar()) {
+                varp->sourceEdge<0>()->unlinkSource();
                 vtx.replaceWith(varp);
-                varp->addDriver(flp, 0, &vtx);
+                varp->srcp(&vtx);
             } else {
                 // Need to create an intermediate variable
                 const std::string name = m_dfg.makeUniqueName("Regularize", m_nTmps);
                 FileLine* const flp = vtx.fileline();
                 AstScope* const scopep = scoped ? vtx.scopep(scopeCache) : nullptr;
-                DfgVarPacked* const newp
-                    = m_dfg.makeNewVar(flp, name, vtx.dtypep(), scopep)->as<DfgVarPacked>();
+                DfgVertexVar* const newp = m_dfg.makeNewVar(flp, name, vtx.dtypep(), scopep);
                 ++m_nTmps;
                 ++m_ctx.m_temporariesIntroduced;
                 // Replace vertex with the variable and add back driver
                 vtx.replaceWith(newp);
-                newp->addDriver(vtx.fileline(), 0, &vtx);
+                newp->srcp(&vtx);
             }
         }
     }

src/V3DfgVertices.h

@@ -38,22 +38,24 @@
 
 // === Abstract base node types (DfgVertex*) ===================================
 
-class DfgVertexVar VL_NOT_FINAL : public DfgVertexVariadic {
+class DfgVertexVar VL_NOT_FINAL : public DfgVertexUnary {
     AstVar* const m_varp;  // The AstVar associated with this vertex (not owned by this vertex)
     AstVarScope* const m_varScopep;  // The AstVarScope associated with this vertex (not owned)
     bool m_hasDfgRefs = false;  // This AstVar is referenced in a different DFG of the module
     bool m_hasModRefs = false;  // This AstVar is referenced outside the DFG, but in the module
     bool m_hasExtRefs = false;  // This AstVar is referenced from outside the module
+    // Location of driver of this variable. Only used for converting back to Ast. Might be nullptr.
+    FileLine* m_driverFileLine = nullptr;
 
     bool selfEquals(const DfgVertex& that) const final VL_MT_DISABLED;
     V3Hash selfHash() const final VL_MT_DISABLED;
 
 public:
-    inline DfgVertexVar(DfgGraph& dfg, VDfgType type, AstVar* varp, uint32_t initialCapacity);
-    inline DfgVertexVar(DfgGraph& dfg, VDfgType type, AstVarScope* vscp, uint32_t initialCapacity);
+    inline DfgVertexVar(DfgGraph& dfg, VDfgType type, AstVar* varp);
+    inline DfgVertexVar(DfgGraph& dfg, VDfgType type, AstVarScope* vscp);
     ASTGEN_MEMBERS_DfgVertexVar;
 
-    bool isDrivenByDfg() const { return arity() > 0; }
+    const std::string srcName(size_t) const override { return ""; }
 
     AstVar* varp() const { return m_varp; }
     AstVarScope* varScopep() const { return m_varScopep; }
@@ -68,6 +70,13 @@ public:
     void setHasExtRefs() { m_hasExtRefs = true; }
     bool hasNonLocalRefs() const { return hasDfgRefs() || hasModRefs() || hasExtRefs(); }
 
+    FileLine* driverFileLine() const { return m_driverFileLine; }
+    void driverFileLine(FileLine* flp) { m_driverFileLine = flp; }
+
+    bool isDrivenFullyByDfg() const {
+        return srcp() && !srcp()->is<DfgVertexSplice>() && !varp()->isForced();
+    }
+
     // Variable cannot be removed, even if redundant in the DfgGraph (might be used externally)
     bool keep() const {
         // Keep if referenced outside this module
@@ -82,6 +91,12 @@ public:
         return false;
     }
 };
+class DfgVertexSplice VL_NOT_FINAL : public DfgVertexVariadic {
+public:
+    DfgVertexSplice(DfgGraph& dfg, VDfgType type, FileLine* flp, AstNodeDType* dtypep)
+        : DfgVertexVariadic{dfg, type, flp, dtypep, 1u} {}
+    ASTGEN_MEMBERS_DfgVertexSplice;
+};
 
 // === Concrete node types =====================================================
 
@@ -178,20 +193,58 @@ class DfgVarArray final : public DfgVertexVar {
     friend class DfgVertex;
     friend class DfgVisitor;
 
-    using DriverData = std::pair<FileLine*, uint32_t>;
-
-    std::vector<DriverData> m_driverData;  // Additional data associate with each driver
-
 public:
     DfgVarArray(DfgGraph& dfg, AstVar* varp)
-        : DfgVertexVar{dfg, dfgType(), varp, 4u} {
+        : DfgVertexVar{dfg, dfgType(), varp} {
         UASSERT_OBJ(VN_IS(dtypep(), UnpackArrayDType), varp, "Non array DfgVarArray");
     }
     DfgVarArray(DfgGraph& dfg, AstVarScope* vscp)
-        : DfgVertexVar{dfg, dfgType(), vscp, 4u} {
+        : DfgVertexVar{dfg, dfgType(), vscp} {
         UASSERT_OBJ(VN_IS(dtypep(), UnpackArrayDType), vscp, "Non array DfgVarArray");
     }
     ASTGEN_MEMBERS_DfgVarArray;
+};
+class DfgVarPacked final : public DfgVertexVar {
+    friend class DfgVertex;
+    friend class DfgVisitor;
+
+public:
+    DfgVarPacked(DfgGraph& dfg, AstVar* varp)
+        : DfgVertexVar{dfg, dfgType(), varp} {
+        UASSERT_OBJ(!VN_IS(dtypep(), UnpackArrayDType), varp, "Array DfgVarPacked");
+    }
+    DfgVarPacked(DfgGraph& dfg, AstVarScope* vscp)
+        : DfgVertexVar{dfg, dfgType(), vscp} {
+        UASSERT_OBJ(!VN_IS(dtypep(), UnpackArrayDType), vscp, "Array DfgVarPacked");
+    }
+    ASTGEN_MEMBERS_DfgVarPacked;
+};
+
+// === DfgVertexSplice ===
+class DfgSpliceArray final : public DfgVertexSplice {
+    friend class DfgVertex;
+    friend class DfgVisitor;
+
+    struct DriverData final {
+        FileLine* m_flp;  // Location of this driver
+        uint32_t m_index;  // Array index driven by this driver (or low index of range)
+        DriverData() = delete;
+        DriverData(FileLine* flp, uint32_t index)
+            : m_flp{flp}
+            , m_index{index} {}
+    };
+
+    std::vector<DriverData> m_driverData;  // Additional data associated with each driver
+
+    bool selfEquals(const DfgVertex& that) const override VL_MT_DISABLED;
+    V3Hash selfHash() const override VL_MT_DISABLED;
+
+public:
+    DfgSpliceArray(DfgGraph& dfg, FileLine* flp, AstNodeDType* dtypep)
+        : DfgVertexSplice{dfg, dfgType(), flp, dtypep} {
+        UASSERT_OBJ(VN_IS(dtypep, UnpackArrayDType), flp, "Non array DfgSpliceArray");
+    }
+    ASTGEN_MEMBERS_DfgSpliceArray;
 
     void addDriver(FileLine* flp, uint32_t index, DfgVertex* vtxp) {
         m_driverData.emplace_back(flp, index);
@@ -203,29 +256,8 @@ public:
         DfgVertexVariadic::resetSources();
     }
 
-    // Remove undriven sources
-    void packSources() {
-        // Grab and reset the driver data
-        std::vector<DriverData> driverData;
-        driverData.swap(m_driverData);
-
-        // Grab and unlink the sources
-        std::vector<DfgVertex*> sources{arity()};
-        forEachSourceEdge([&](DfgEdge& edge, size_t idx) {
-            sources[idx] = edge.sourcep();
-            edge.unlinkSource();
-        });
-        DfgVertexVariadic::resetSources();
-
-        // Add back the driven sources
-        for (size_t i = 0; i < sources.size(); ++i) {
-            if (!sources[i]) continue;
-            addDriver(driverData[i].first, driverData[i].second, sources[i]);
-        }
-    }
-
-    FileLine* driverFileLine(size_t idx) const { return m_driverData[idx].first; }
-    uint32_t driverIndex(size_t idx) const { return m_driverData[idx].second; }
+    FileLine* driverFileLine(size_t i) const { return m_driverData.at(i).m_flp; }
+    uint32_t driverIndex(size_t i) const { return m_driverData.at(i).m_index; }
 
     DfgVertex* driverAt(size_t idx) const {
         const DfgEdge* const edgep = findSourceEdge([this, idx](const DfgEdge&, size_t i) {  //
@@ -234,26 +266,33 @@ public:
         return edgep ? edgep->sourcep() : nullptr;
     }
 
-    const string srcName(size_t idx) const override { return cvtToStr(driverIndex(idx)); }
+    const std::string srcName(size_t idx) const override {
+        return std::to_string(driverIndex(idx));
+    }
 };
-class DfgVarPacked final : public DfgVertexVar {
+class DfgSplicePacked final : public DfgVertexSplice {
     friend class DfgVertex;
     friend class DfgVisitor;
 
-    using DriverData = std::pair<FileLine*, uint32_t>;
+    struct DriverData final {
+        FileLine* m_flp;  // Location of this driver
+        uint32_t m_lsb;  // LSB of range driven by this driver
+        DriverData() = delete;
+        DriverData(FileLine* flp, uint32_t lsb)
+            : m_flp{flp}
+            , m_lsb{lsb} {}
+    };
+    std::vector<DriverData> m_driverData;  // Additional data associated with each driver
 
-    std::vector<DriverData> m_driverData;  // Additional data associate with each driver
+    bool selfEquals(const DfgVertex& that) const override VL_MT_DISABLED;
+    V3Hash selfHash() const override VL_MT_DISABLED;
 
 public:
-    DfgVarPacked(DfgGraph& dfg, AstVar* varp)
-        : DfgVertexVar{dfg, dfgType(), varp, 1u} {}
-    DfgVarPacked(DfgGraph& dfg, AstVarScope* vscp)
-        : DfgVertexVar{dfg, dfgType(), vscp, 1u} {}
-    ASTGEN_MEMBERS_DfgVarPacked;
-
-    bool isDrivenFullyByDfg() const {
-        return arity() == 1 && source(0)->dtypep() == dtypep() && !varp()->isForced();
+    DfgSplicePacked(DfgGraph& dfg, FileLine* flp, AstNodeDType* dtypep)
+        : DfgVertexSplice{dfg, dfgType(), flp, dtypep} {
+        UASSERT_OBJ(!VN_IS(dtypep, UnpackArrayDType), flp, "Array DfgSplicePacked");
     }
+    ASTGEN_MEMBERS_DfgSplicePacked;
 
     void addDriver(FileLine* flp, uint32_t lsb, DfgVertex* vtxp) {
         m_driverData.emplace_back(flp, lsb);
@@ -265,33 +304,10 @@ public:
         DfgVertexVariadic::resetSources();
     }
 
-    // Remove undriven sources
-    void packSources() {
-        // Grab and reset the driver data
-        std::vector<DriverData> driverData;
-        driverData.swap(m_driverData);
+    FileLine* driverFileLine(size_t i) const { return m_driverData.at(i).m_flp; }
+    uint32_t driverLsb(size_t i) const { return m_driverData.at(i).m_lsb; }
 
-        // Grab and unlink the sources
-        std::vector<DfgVertex*> sources{arity()};
-        forEachSourceEdge([&](DfgEdge& edge, size_t idx) {
-            sources[idx] = edge.sourcep();
-            edge.unlinkSource();
-        });
-        DfgVertexVariadic::resetSources();
-
-        // Add back the driven sources
-        for (size_t i = 0; i < sources.size(); ++i) {
-            if (!sources[i]) continue;
-            addDriver(driverData[i].first, driverData[i].second, sources[i]);
-        }
-    }
-
-    FileLine* driverFileLine(size_t idx) const { return m_driverData[idx].first; }
-    uint32_t driverLsb(size_t idx) const { return m_driverData[idx].second; }
-
-    const string srcName(size_t idx) const override {
-        return isDrivenFullyByDfg() ? "" : cvtToStr(driverLsb(idx));
-    }
+    const std::string srcName(size_t idx) const override { return std::to_string(driverLsb(idx)); }
 };
 
 #endif

src/V3EmitCFunc.cpp

@@ -247,14 +247,14 @@ void EmitCFunc::displayArg(AstNode* dispp, AstNode** elistp, bool isScan, const
     AstNode* argp = nullptr;
     if (!ignore) {
         argp = *elistp;
-        // Prep for next parameter
-        *elistp = (*elistp)->nextp();
         if (VL_UNCOVERABLE(!argp)) {
             // expectDisplay() checks this first, so internal error if found here
             dispp->v3error(
                 "Internal: Missing arguments for $display-like format");  // LCOV_EXCL_LINE
             return;  // LCOV_EXCL_LINE
         }
+        // Prep for next parameter
+        *elistp = (*elistp)->nextp();
         if (argp->widthMin() > VL_VALUE_STRING_MAX_WIDTH) {
             dispp->v3warn(E_UNSUPPORTED, "Unsupported: Exceeded limit of "
                                              + cvtToStr(VL_VALUE_STRING_MAX_WIDTH)

src/V3EmitCFunc.h

@@ -261,33 +261,57 @@ public:
         if (const AstCNew* const cnewp = getSuperNewCallRecursep(nodep->nextp())) return cnewp;
         return nullptr;
     }
-
-    void putConstructorSubinit(const AstClass* classp, AstCFunc* cfuncp, bool top,
-                               std::set<AstClass*>& doneClassesr) {
+    void putConstructorSubinit(const AstClass* classp, AstCFunc* cfuncp) {
+        // Virtual bases in depth-first left-to-right order
+        std::vector<AstClass*> virtualBases;
+        std::unordered_set<AstClass*> doneClasses;
+        collectVirtualBasesRecursep(classp, virtualBases);
+        for (AstClass* vbase : virtualBases) {
+            if (doneClasses.count(vbase)) continue;
+            puts(doneClasses.empty() ? "" : "\n    , ");
+            doneClasses.emplace(vbase);
+            puts(prefixNameProtect(vbase));
+            if (constructorNeedsProcess(vbase)) {
+                puts("(vlProcess, vlSymsp)");
+            } else {
+                puts("(vlSymsp)");
+            }
+        }
+        const AstCNew* const superNewCallp = getSuperNewCallRecursep(cfuncp->stmtsp());
+        // Direct non-virtual bases in declaration order
         for (const AstClassExtends* extp = classp->extendsp(); extp;
              extp = VN_AS(extp->nextp(), ClassExtends)) {
-            if (extp->classp()->useVirtualPublic()) {
-                // It's a c++ virtual class (diamond relation)
-                // Must get the subclasses initialized first
-                putConstructorSubinit(extp->classp(), cfuncp, false, doneClassesr);
-            }
-            // Diamond pattern with same base class twice?
-            if (doneClassesr.find(extp->classp()) != doneClassesr.end()) continue;
-            puts(doneClassesr.empty() ? "" : "\n    , ");
-            doneClassesr.emplace(extp->classp());
+            if (extp->classp()->useVirtualPublic()) continue;
+            if (doneClasses.count(extp->classp())) continue;
+            puts(doneClasses.empty() ? "" : "\n    , ");
+            doneClasses.emplace(extp->classp());
             puts(prefixNameProtect(extp->classp()));
             if (constructorNeedsProcess(extp->classp())) {
                 puts("(vlProcess, vlSymsp");
             } else {
                 puts("(vlSymsp");
             }
-            if (top) {
-                const AstCNew* const superNewCallp = getSuperNewCallRecursep(cfuncp->stmtsp());
-                UASSERT_OBJ(superNewCallp, cfuncp, "super.new call not found");
+            // Handle super.new() args for the concrete parent
+            if (!extp->classp()->isInterfaceClass() && superNewCallp) {
                 putCommaIterateNext(superNewCallp->argsp(), true);
             }
             puts(")");
-            top = false;
+        }
+    }
+    void collectVirtualBasesRecursep(const AstClass* classp,
+                                     std::vector<AstClass*>& virtualBases) {
+        std::set<const AstClass*> visited;
+        collectVirtualBasesRecursep(classp, virtualBases /*ref*/, visited /*ref*/);
+    }
+    void collectVirtualBasesRecursep(const AstClass* classp, std::vector<AstClass*>& virtualBases,
+                                     std::set<const AstClass*>& visited) {
+        if (visited.count(classp)) return;
+        visited.emplace(classp);
+        for (const AstClassExtends* extp = classp->extendsp(); extp;
+             extp = VN_AS(extp->nextp(), ClassExtends)) {
+            // Depth-first: recurse into this base first
+            collectVirtualBasesRecursep(extp->classp(), virtualBases, visited);
+            if (extp->classp()->useVirtualPublic()) { virtualBases.push_back(extp->classp()); }
         }
     }
 
@@ -314,8 +338,7 @@ public:
             const AstClass* const classp = VN_CAST(nodep->scopep()->modp(), Class);
             if (nodep->isConstructor() && classp && classp->extendsp()) {
                 puts("\n    : ");
-                std::set<AstClass*> doneClasses;
-                putConstructorSubinit(classp, nodep, true, doneClasses /*ref*/);
+                putConstructorSubinit(classp, nodep);
             }
         }
         puts(" {\n");

src/V3EmitCHeaders.cpp

@@ -564,16 +564,20 @@ class EmitCHeader final : public EmitCConstInit {
         if (!VN_IS(modp, Class)) puts("alignas(VL_CACHE_LINE_BYTES) ");
         puts(prefixNameProtect(modp));
         if (const AstClass* const classp = VN_CAST(modp, Class)) {
-            const string virtpub = classp->useVirtualPublic() ? "virtual public " : "public ";
-            puts(" : " + virtpub);
+            puts(" : ");
             if (classp->extendsp()) {
+                bool needComma = false;
                 for (const AstClassExtends* extp = classp->extendsp(); extp;
                      extp = VN_AS(extp->nextp(), ClassExtends)) {
+                    if (needComma) puts(", ");
+                    // Use virtual only for interfaces for class inheritance
+                    // (extends)
+                    puts(extp->classp()->useVirtualPublic() ? "virtual public " : "public ");
                     putns(extp, prefixNameProtect(extp->classp()));
-                    if (extp->nextp()) puts(", " + virtpub);
+                    needComma = true;
                 }
             } else {
-                puts("VlClass");
+                puts("public virtual VlClass");
             }
         } else {
             puts(" final : public VerilatedModule");

src/V3EmitCSyms.cpp

@@ -964,9 +964,9 @@ void EmitCSyms::emitSymImp() {
                     } else {
                         if (basicp->isRanged()) {
                             bounds += " ,";
-                            bounds += cvtToStr(basicp->hi());
+                            bounds += cvtToStr(basicp->left());
                             bounds += ",";
-                            bounds += cvtToStr(basicp->lo());
+                            bounds += cvtToStr(basicp->right());
                             pdim++;
                         }
                         break;  // AstBasicDType - nothing below, 1

src/V3EmitV.cpp

@@ -922,6 +922,20 @@ class EmitVBaseVisitorConst VL_NOT_FINAL : public EmitCBaseVisitorConst {
         m_sensesp = nodep->sensesp();
         iterateAndNextConstNull(nodep->stmtsp());
     }
+    void visit(AstDelay* nodep) override {
+        puts("");  // this is for proper alignment
+        puts("#");
+        iterateConst(nodep->lhsp());
+        puts(";\n");
+        iterateAndNextConstNull(nodep->stmtsp());
+    }
+    void visit(AstCAwait* nodep) override {
+        AstCMethodHard* methodp = VN_CAST(nodep->exprp(), CMethodHard);
+        UASSERT_OBJ(methodp, nodep, "AstCAwait expression must be an AstCMethodHard");
+        puts("");  // this is for proper alignment
+        puts("#");
+        iterateConst(methodp->pinsp());
+    }
     void visit(AstParseRef* nodep) override { puts(nodep->prettyName()); }
     void visit(AstNodeText*) override {}
     void visit(AstVarScope*) override {}

src/V3Error.h

@@ -99,6 +99,7 @@ public:
         DEPRECATED,     // Feature will be deprecated
         ENCAPSULATED,   // Error: local/protected violation
         ENDLABEL,       // End lable name mismatch
+        ENUMITEMWIDTH,  // Error: enum item width mismatch
         ENUMVALUE,      // Error: enum type needs explicit cast
         EOFNEWLINE,     // End-of-file missing newline
         GENCLK,         // Generated Clock. Historical, never issued.
@@ -124,6 +125,7 @@ public:
         MULTIDRIVEN,    // Driven from multiple blocks
         MULTITOP,       // Multiple top level modules
         NEWERSTD,       // Newer language standard required
+        NOEFFECT,       // Statement has no effect
         NOLATCH,        // No latch detected in always_latch block
         NONSTD,         // Non-standard feature present in other sims
         NULLPORT,       // Null port detected in module definition
@@ -144,6 +146,7 @@ public:
         SELRANGE,       // Selection index out of range
         SHORTREAL,      // Shortreal not supported
         SIDEEFFECT,     // Sideeffect ignored
+        SPECIFYIGN,     // Specify construct ignored
         SPLITVAR,       // Cannot split the variable
         STATICVAR,      // Static variable declared in a loop with a declaration assignment
         STMTDLY,        // Delayed statement
@@ -189,40 +192,33 @@ public:
         : m_e(static_cast<en>(_e)) {}  // Need () or GCC 4.8 false warning
     constexpr operator en() const VL_MT_SAFE { return m_e; }
     const char* ascii() const VL_MT_SAFE {
-        // clang-format off
         static const char* const names[] = {
             // Leading spaces indicate it can't be disabled.
             " MIN", " INFO", " FATAL", " FATALMANY", " FATALSRC", " ERROR", " FIRST_NAMED",
             // Boolean
-            " I_CELLDEFINE", " I_COVERAGE",  " I_DEF_NETTYPE_WIRE", " I_LINT", " I_TIMING", " I_TRACING", " I_UNUSED",
+            " I_CELLDEFINE", " I_COVERAGE", " I_DEF_NETTYPE_WIRE", " I_LINT", " I_TIMING",
+            " I_TRACING", " I_UNUSED",
             // Errors
             "LIFETIME", "NEEDTIMINGOPT", "NOTIMING", "PORTSHORT", "TASKNSVAR", "UNSUPPORTED",
             // Warnings
-            " EC_FIRST_WARN",
-            "ALWCOMBORDER", "ASCRANGE", "ASSIGNDLY", "ASSIGNIN", "BADSTDPRAGMA", "BADVLTPRAGMA",
-            "BLKANDNBLK", "BLKLOOPINIT", "BLKSEQ", "BSSPACE",
-            "CASEINCOMPLETE", "CASEOVERLAP", "CASEWITHX", "CASEX", "CASTCONST", "CDCRSTLOGIC", "CLKDATA",
-            "CMPCONST", "COLONPLUS", "COMBDLY", "CONSTRAINTIGN", "CONTASSREG", "COVERIGN",
-            "DECLFILENAME", "DEFOVERRIDE", "DEFPARAM", "DEPRECATED",
-            "ENCAPSULATED", "ENDLABEL", "ENUMVALUE", "EOFNEWLINE", "GENCLK",
-            "GENUNNAMED", "HIERBLOCK",
-            "IFDEPTH", "IGNOREDRETURN",
-            "IMPERFECTSCH", "IMPLICIT", "IMPLICITSTATIC", "IMPORTSTAR", "IMPURE",
-            "INCABSPATH", "INFINITELOOP", "INITIALDLY", "INSECURE",
-            "LATCH", "LITENDIAN", "MINTYPMAXDLY", "MISINDENT", "MODDUP", "MODMISSING",
-            "MULTIDRIVEN", "MULTITOP", "NEWERSTD", "NOLATCH", "NONSTD", "NULLPORT", "PINCONNECTEMPTY",
-            "PINMISSING", "PINNOCONNECT",  "PINNOTFOUND", "PKGNODECL", "PREPROCZERO", "PROCASSINIT", "PROCASSWIRE",
-            "PROFOUTOFDATE", "PROTECTED", "RANDC", "REALCVT", "REDEFMACRO", "RISEFALLDLY",
-            "SELRANGE", "SHORTREAL", "SIDEEFFECT", "SPLITVAR",
-            "STATICVAR", "STMTDLY", "SYMRSVDWORD", "SYNCASYNCNET",
-            "TICKCOUNT", "TIMESCALEMOD",
-            "UNDRIVEN", "UNOPT", "UNOPTFLAT", "UNOPTTHREADS",
-            "UNPACKED", "UNSIGNED", "UNUSEDGENVAR",  "UNUSEDLOOP" ,"UNUSEDPARAM", "UNUSEDSIGNAL",
-            "USERERROR", "USERFATAL", "USERINFO", "USERWARN",
-            "VARHIDDEN", "WAITCONST", "WIDTH", "WIDTHCONCAT",  "WIDTHEXPAND", "WIDTHTRUNC", "WIDTHXZEXPAND", "ZERODLY", "ZEROREPL",
-            " MAX"
-        };
-        // clang-format on
+            " EC_FIRST_WARN", "ALWCOMBORDER", "ASCRANGE", "ASSIGNDLY", "ASSIGNIN", "BADSTDPRAGMA",
+            "BADVLTPRAGMA", "BLKANDNBLK", "BLKLOOPINIT", "BLKSEQ", "BSSPACE", "CASEINCOMPLETE",
+            "CASEOVERLAP", "CASEWITHX", "CASEX", "CASTCONST", "CDCRSTLOGIC", "CLKDATA", "CMPCONST",
+            "COLONPLUS", "COMBDLY", "CONSTRAINTIGN", "CONTASSREG", "COVERIGN", "DECLFILENAME",
+            "DEFOVERRIDE", "DEFPARAM", "DEPRECATED", "ENCAPSULATED", "ENDLABEL", "ENUMITEMWIDTH",
+            "ENUMVALUE", "EOFNEWLINE", "GENCLK", "GENUNNAMED", "HIERBLOCK", "IFDEPTH",
+            "IGNOREDRETURN", "IMPERFECTSCH", "IMPLICIT", "IMPLICITSTATIC", "IMPORTSTAR", "IMPURE",
+            "INCABSPATH", "INFINITELOOP", "INITIALDLY", "INSECURE", "LATCH", "LITENDIAN",
+            "MINTYPMAXDLY", "MISINDENT", "MODDUP", "MODMISSING", "MULTIDRIVEN", "MULTITOP",
+            "NEWERSTD", "NOEFFECT", "NOLATCH", "NONSTD", "NULLPORT", "PINCONNECTEMPTY",
+            "PINMISSING", "PINNOCONNECT", "PINNOTFOUND", "PKGNODECL", "PREPROCZERO", "PROCASSINIT",
+            "PROCASSWIRE", "PROFOUTOFDATE", "PROTECTED", "RANDC", "REALCVT", "REDEFMACRO",
+            "RISEFALLDLY", "SELRANGE", "SHORTREAL", "SIDEEFFECT", "SPECIFYIGN", "SPLITVAR",
+            "STATICVAR", "STMTDLY", "SYMRSVDWORD", "SYNCASYNCNET", "TICKCOUNT", "TIMESCALEMOD",
+            "UNDRIVEN", "UNOPT", "UNOPTFLAT", "UNOPTTHREADS", "UNPACKED", "UNSIGNED",
+            "UNUSEDGENVAR", "UNUSEDLOOP", "UNUSEDPARAM", "UNUSEDSIGNAL", "USERERROR", "USERFATAL",
+            "USERINFO", "USERWARN", "VARHIDDEN", "WAITCONST", "WIDTH", "WIDTHCONCAT",
+            "WIDTHEXPAND", "WIDTHTRUNC", "WIDTHXZEXPAND", "ZERODLY", "ZEROREPL", " MAX"};
         return names[m_e];
     }
     // Warnings that default to off
@@ -249,9 +245,9 @@ public:
     bool pretendError() const VL_MT_SAFE {
         return (m_e == ASSIGNIN || m_e == BADSTDPRAGMA || m_e == BADVLTPRAGMA || m_e == BLKANDNBLK
                 || m_e == BLKLOOPINIT || m_e == CONTASSREG || m_e == ENCAPSULATED
-                || m_e == ENDLABEL || m_e == ENUMVALUE || m_e == IMPURE || m_e == MODMISSING
-                || m_e == PINNOTFOUND || m_e == PKGNODECL || m_e == PROCASSWIRE
-                || m_e == ZEROREPL  // Says IEEE
+                || m_e == ENDLABEL || m_e == ENUMITEMWIDTH || m_e == ENUMVALUE || m_e == IMPURE
+                || m_e == MODMISSING || m_e == PINNOTFOUND || m_e == PKGNODECL
+                || m_e == PROCASSWIRE || m_e == ZEROREPL  // Says IEEE
         );
     }
     // Warnings to mention manual

src/V3FileLine.h

@@ -369,6 +369,10 @@ public:
                 && m_lastLineno == rhs.m_lastLineno && m_lastColumn == rhs.m_lastColumn
                 && m_filenameno == rhs.m_filenameno && m_msgEnIdx == rhs.m_msgEnIdx);
     }
+    bool equalFirstLineCol(const FileLine& rhs) const {
+        return (m_filenameno == rhs.m_filenameno && m_firstLineno == rhs.m_firstLineno
+                && m_firstColumn == rhs.m_firstColumn);
+    }
     // Returns -1 if (*this) should come before rhs after sorted. 1 for the opposite case. 0 for
     // equivalent.
     int operatorCompare(const FileLine& rhs) const {

src/V3Gate.cpp

@@ -304,8 +304,14 @@ class GateBuildVisitor final : public VNVisitorConst {
 
         // We use weight of one; if we ref the var more than once, when we simplify,
         // the weight will increase
-        if (nodep->access().isWriteOrRW()) m_graphp->addEdge(m_logicVertexp, vVtxp, 1);
-        if (nodep->access().isReadOrRW()) m_graphp->addEdge(vVtxp, m_logicVertexp, 1);
+        if (VN_IS(nodep->backp(), CoverToggle)) {
+            // Temporary workaround. Otherwise assignments to initp() var are removed
+            m_graphp->addEdge(m_logicVertexp, vVtxp, 1);
+            m_graphp->addEdge(vVtxp, m_logicVertexp, 1);
+        } else {
+            if (nodep->access().isWriteOrRW()) m_graphp->addEdge(m_logicVertexp, vVtxp, 1);
+            if (nodep->access().isReadOrRW()) m_graphp->addEdge(vVtxp, m_logicVertexp, 1);
+        }
     }
     void visit(AstConcat* nodep) override {
         UASSERT_OBJ(!(VN_IS(nodep->backp(), NodeAssign)

src/V3LinkDot.cpp

@@ -779,14 +779,51 @@ public:
         if (!foundp) baddot = dotname;
         return foundp;
     }
+    static bool checkIfClassOrPackage(const VSymEnt* const symp) {
+        if (VN_IS(symp->nodep(), Class) || VN_IS(symp->nodep(), Package)) return true;
+        const AstRefDType* refDTypep = nullptr;
+        if (const AstTypedef* const typedefp = VN_CAST(symp->nodep(), Typedef)) {
+            if (VN_IS(typedefp->childDTypep(), ClassRefDType)) return true;
+            if (const AstRefDType* const refp = VN_CAST(typedefp->childDTypep(), RefDType)) {
+                refDTypep = refp;
+            }
+        } else if (const AstParamTypeDType* const paramTypep
+                   = VN_CAST(symp->nodep(), ParamTypeDType)) {
+            if (const AstRequireDType* const requireDTypep
+                = VN_CAST(paramTypep->childDTypep(), RequireDType)) {
+                if (const AstRefDType* const refp = VN_CAST(requireDTypep->lhsp(), RefDType)) {
+                    refDTypep = refp;
+                } else if (VN_IS(requireDTypep->lhsp(), VoidDType)
+                           || VN_IS(requireDTypep->lhsp(), BasicDType)
+                           || VN_IS(requireDTypep->lhsp(), ClassRefDType)) {
+                    return true;
+                }
+            }
+        }
+        // TODO: this should be handled properly - case when it is known what type is
+        // referenced by AstRefDType (refDTypep->typeofp() is null or
+        // refDTypep->classOrPackageOpp() is null)
+        if (refDTypep && !refDTypep->typeofp() && !refDTypep->classOrPackageOpp()) {
+            // When still unknown - return because it may be a class, classes may not be
+            // linked at this point. Return in case it gets resolved to a class in the future
+            return true;
+        }
+        return false;
+    }
     VSymEnt* resolveClassOrPackage(VSymEnt* lookSymp, AstClassOrPackageRef* nodep, bool fallback,
                                    bool classOnly, const string& forWhat) {
         if (nodep->classOrPackageSkipp()) return getNodeSym(nodep->classOrPackageSkipp());
         VSymEnt* foundp;
         if (fallback) {
-            foundp = lookSymp->findIdFallback(nodep->name());
+            VSymEnt* currentLookSymp = lookSymp;
+            do {
+                foundp = currentLookSymp->findIdFlat(nodep->name());
+                if (foundp && !checkIfClassOrPackage(foundp)) foundp = nullptr;
+                if (!foundp) currentLookSymp = currentLookSymp->fallbackp();
+            } while (!foundp && currentLookSymp);
         } else {
             foundp = lookSymp->findIdFlat(nodep->name());
+            if (foundp && !checkIfClassOrPackage(foundp)) foundp = nullptr;
         }
         if (!foundp && v3Global.rootp()->stdPackagep()) {  // Look under implied std::
             foundp = getNodeSym(v3Global.rootp()->stdPackagep())->findIdFlat(nodep->name());
@@ -3552,9 +3589,6 @@ class LinkDotResolveVisitor final : public VNVisitor {
         UINFO(9, indent() << m_ds.ascii());
         VL_RESTORER(m_usedPins);
         m_usedPins.clear();
-        UASSERT_OBJ(m_statep->forPrimary() || VN_IS(nodep->classOrPackageNodep(), ParamTypeDType)
-                        || nodep->classOrPackageSkipp(),
-                    nodep, "ClassRef has unlinked class");
         UASSERT_OBJ(m_statep->forPrimary() || !nodep->paramsp(), nodep,
                     "class reference parameter not removed by V3Param");
         {
@@ -3565,6 +3599,10 @@ class LinkDotResolveVisitor final : public VNVisitor {
                 m_statep->resolveClassOrPackage(m_ds.m_dotSymp, nodep, m_ds.m_dotPos != DP_PACKAGE,
                                                 false, ":: reference");
             }
+            UASSERT_OBJ(m_statep->forPrimary()
+                            || VN_IS(nodep->classOrPackageNodep(), ParamTypeDType)
+                            || nodep->classOrPackageSkipp(),
+                        nodep, "ClassRef has unlinked class");
 
             // ClassRef's have pins, so track
             if (nodep->classOrPackageSkipp()) {

src/V3LinkJump.cpp

@@ -35,6 +35,7 @@
 
 #include "V3AstUserAllocator.h"
 #include "V3Error.h"
+#include "V3UniqueNames.h"
 
 #include <vector>
 
@@ -60,6 +61,8 @@ class LinkJumpVisitor final : public VNVisitor {
     int m_modRepeatNum = 0;  // Repeat counter
     VOptionBool m_unrollFull;  // Pragma full, disable, or default unrolling
     std::vector<AstNodeBlock*> m_blockStack;  // All begin blocks above current node
+    V3UniqueNames m_queueNames{
+        "__VprocessQueue"};  // Names for queues needed for 'disable' handling
 
     // METHODS
     AstJumpLabel* findAddLabel(AstNode* nodep, bool endOfIter) {
@@ -159,6 +162,79 @@ class LinkJumpVisitor final : public VNVisitor {
         if (AstNode* const refp = nodep->op4p()) addPrefixToBlocksRecurse(prefix, refp);
         if (AstNode* const refp = nodep->nextp()) addPrefixToBlocksRecurse(prefix, refp);
     }
+    static AstNode* getMemberp(const AstNodeModule* const nodep, const std::string& name) {
+        for (AstNode* itemp = nodep->stmtsp(); itemp; itemp = itemp->nextp()) {
+            if (itemp->name() == name) return itemp;
+        }
+        return nullptr;
+    }
+    bool existsBlockAbove(const std::string& name) const {
+        for (const AstNodeBlock* const stackp : vlstd::reverse_view(m_blockStack)) {
+            if (stackp->name() == name) return true;
+        }
+        return false;
+    }
+    static AstStmtExpr* getQueuePushProcessSelfp(AstVarRef* const queueRefp) {
+        // Constructs queue.push_back(std::process::self()) statement
+        FileLine* const fl = queueRefp->fileline();
+        AstClass* const processClassp
+            = VN_AS(getMemberp(v3Global.rootp()->stdPackagep(), "process"), Class);
+        AstFunc* const selfMethodp = VN_AS(getMemberp(processClassp, "self"), Func);
+        AstFuncRef* const processSelfp = new AstFuncRef{fl, selfMethodp, nullptr};
+        processSelfp->classOrPackagep(processClassp);
+        return new AstStmtExpr{
+            fl, new AstMethodCall{fl, queueRefp, "push_back", new AstArg{fl, "", processSelfp}}};
+    }
+    void handleDisableOnFork(AstDisable* const nodep, const std::vector<AstBegin*>& forks) {
+        // The support is limited only to disabling a fork from outside that fork.
+        // It utilizes the process::kill()` method. For each `disable` a queue of processes is
+        // declared. At the beginning of each fork that can be disabled, its process handle is
+        // pushed to the queue. `disable` statement is replaced with calling `kill()` method on
+        // each element of the queue.
+        FileLine* const fl = nodep->fileline();
+        const std::string targetName = nodep->targetp()->name();
+        if (existsBlockAbove(targetName)) {
+            nodep->v3warn(E_UNSUPPORTED, "Unsupported: disabling fork from within same fork");
+        }
+        if (m_ftaskp) {
+            nodep->v3warn(E_UNSUPPORTED, "Unsupported: disabling fork from task / function");
+        }
+        AstPackage* const topPkgp = v3Global.rootp()->dollarUnitPkgAddp();
+        AstClass* const processClassp
+            = VN_AS(getMemberp(v3Global.rootp()->stdPackagep(), "process"), Class);
+        // Declare queue of processes (as a global variable for simplicity)
+        AstVar* const processQueuep = new AstVar{
+            fl, VVarType::VAR, m_queueNames.get(targetName), VFlagChildDType{},
+            new AstQueueDType{fl, VFlagChildDType{},
+                              new AstClassRefDType{fl, processClassp, nullptr}, nullptr}};
+        processQueuep->lifetime(VLifetime::STATIC);
+        topPkgp->addStmtsp(processQueuep);
+
+        AstVarRef* const queueWriteRefp
+            = new AstVarRef{fl, topPkgp, processQueuep, VAccess::WRITE};
+        AstStmtExpr* pushCurrentProcessp = getQueuePushProcessSelfp(queueWriteRefp);
+
+        for (AstBegin* const beginp : forks) {
+            if (pushCurrentProcessp->backp()) {
+                pushCurrentProcessp = pushCurrentProcessp->cloneTree(false);
+            }
+            if (beginp->stmtsp()) {
+                // There is no need to add it to empty block
+                beginp->stmtsp()->addHereThisAsNext(pushCurrentProcessp);
+            }
+        }
+        AstVarRef* const queueRefp = new AstVarRef{fl, topPkgp, processQueuep, VAccess::READWRITE};
+        AstTaskRef* const killQueueCall
+            = new AstTaskRef{fl, VN_AS(getMemberp(processClassp, "killQueue"), Task),
+                             new AstArg{fl, "", queueRefp}};
+        killQueueCall->classOrPackagep(processClassp);
+        nodep->addNextHere(new AstStmtExpr{fl, killQueueCall});
+    }
+    static bool directlyUnderFork(const AstNode* const nodep) {
+        if (nodep->backp()->nextp() == nodep) return directlyUnderFork(nodep->backp());
+        if (VN_IS(nodep->backp(), Fork)) return true;
+        return false;
+    }
 
     // VISITORS
     void visit(AstNodeModule* nodep) override {
@@ -338,33 +414,44 @@ class LinkJumpVisitor final : public VNVisitor {
     void visit(AstDisable* nodep) override {
         UINFO(8, "   DISABLE " << nodep);
         AstNode* const targetp = nodep->targetp();
+        FileLine* const fl = nodep->fileline();
         UASSERT_OBJ(targetp, nodep, "Unlinked disable statement");
         if (VN_IS(targetp, Task)) {
             nodep->v3warn(E_UNSUPPORTED, "Unsupported: disabling task by name");
-        } else if (VN_IS(targetp, Fork)) {
-            nodep->v3warn(E_UNSUPPORTED, "Unsupported: disabling fork by name");
-        } else if (AstBegin* const beginp = VN_CAST(targetp, Begin)) {
-            const std::string targetName = beginp->name();
-            bool aboveBlock = false;
-            for (AstNodeBlock* const stackp : vlstd::reverse_view(m_blockStack)) {
-                UINFO(9, "    UNDERBLK  " << stackp);
-                if (stackp->name() == targetName) {
-                    aboveBlock = true;
-                    break;
+        } else if (AstFork* const forkp = VN_CAST(targetp, Fork)) {
+            std::vector<AstBegin*> forks;
+            for (AstNode* forkItemp = forkp->stmtsp(); forkItemp; forkItemp = forkItemp->nextp()) {
+                // Further handling of disable stmt requires all forks to be begin blocks
+                AstBegin* beginp = VN_CAST(forkItemp, Begin);
+                if (!beginp) {
+                    beginp = new AstBegin{fl, "", nullptr};
+                    forkItemp->replaceWith(beginp);
+                    beginp->addStmtsp(forkItemp);
+                    // In order to continue the iteration
+                    forkItemp = beginp;
                 }
+                forks.push_back(beginp);
             }
-            if (aboveBlock) {
-                if (beginp->user3()) {
-                    nodep->v3warn(E_UNSUPPORTED,
-                                  "Unsupported: disabling block that contains a fork");
-                } else {
-                    // Jump to the end of the named block
-                    AstJumpLabel* const labelp = findAddLabel(beginp, false);
-                    nodep->addNextHere(new AstJumpGo{nodep->fileline(), labelp});
-                }
+            handleDisableOnFork(nodep, forks);
+        } else if (AstBegin* const beginp = VN_CAST(targetp, Begin)) {
+            if (directlyUnderFork(beginp)) {
+                std::vector<AstBegin*> forks{beginp};
+                handleDisableOnFork(nodep, forks);
             } else {
-                nodep->v3warn(E_UNSUPPORTED, "disable isn't underneath a begin with name: '"
-                                                 << targetName << "'");
+                const std::string targetName = beginp->name();
+                if (existsBlockAbove(targetName)) {
+                    if (beginp->user3()) {
+                        nodep->v3warn(E_UNSUPPORTED,
+                                      "Unsupported: disabling block that contains a fork");
+                    } else {
+                        // Jump to the end of the named block
+                        AstJumpLabel* const labelp = findAddLabel(beginp, false);
+                        nodep->addNextHere(new AstJumpGo{nodep->fileline(), labelp});
+                    }
+                } else {
+                    nodep->v3warn(E_UNSUPPORTED, "disable isn't underneath a begin with name: '"
+                                                     << targetName << "'");
+                }
             }
         } else {
             nodep->v3fatalSrc("Disable linked with node of unhandled type "

src/V3LinkParse.cpp

@@ -267,16 +267,17 @@ class LinkParseVisitor final : public VNVisitor {
             const int left = nodep->rangep()->leftConst();
             const int right = nodep->rangep()->rightConst();
             const int increment = (left > right) ? -1 : 1;
-            int offset_from_init = 0;
+            uint32_t offset_from_init = 0;
             AstEnumItem* addp = nullptr;
             FileLine* const flp = nodep->fileline();
-            for (int i = left; i != (right + increment); i += increment, offset_from_init++) {
+            for (int i = left; i != (right + increment); i += increment, ++offset_from_init) {
                 const string name = nodep->name() + cvtToStr(i);
                 AstNodeExpr* valuep = nullptr;
                 if (nodep->valuep()) {
+                    // V3Width looks for Adds with same fileline as the EnumItem
                     valuep
                         = new AstAdd{flp, nodep->valuep()->cloneTree(true),
-                                     new AstConst(flp, AstConst::Unsized32{}, offset_from_init)};
+                                     new AstConst{flp, AstConst::Unsized32{}, offset_from_init}};
                 }
                 addp = AstNode::addNext(addp, new AstEnumItem{flp, name, nullptr, valuep});
             }
@@ -577,7 +578,7 @@ class LinkParseVisitor final : public VNVisitor {
         } else if (VN_IS(bracketp, SelLoopVars)) {
             // Ok
         } else {
-            nodep->v3error("Syntax error; foreach missing bracketed loop variable"
+            nodep->v3error("Foreach missing bracketed loop variable is no-operation"
                            " (IEEE 1800-2023 12.7.3)");
             VL_DO_DANGLING(nodep->unlinkFrBack()->deleteTree(), nodep);
             return;

src/V3Number.cpp

@@ -1188,7 +1188,7 @@ uint32_t V3Number::countOnes() const {
 
 uint32_t V3Number::mostSetBitP1() const {
     for (int bit = width() - 1; bit >= 0; bit--) {
-        if (bitIs1(bit)) return bit + 1;
+        if (!bitIs0(bit)) return bit + 1;
     }
     return 0;
 }
@@ -2242,6 +2242,13 @@ V3Number& V3Number::opBufIf1(const V3Number& ens, const V3Number& if1s) {
     return *this;
 }
 
+// Sets all bits in range to the given value
+V3Number& V3Number::opSetRange(uint32_t lsb, uint32_t width, char bitValue) {
+    const uint32_t msb = lsb + width - 1;
+    for (uint32_t i = lsb; i <= msb; ++i) setBit(i, bitValue);
+    return *this;
+}
+
 V3Number& V3Number::opAssign(const V3Number& lhs) { return opAssignNonXZ(lhs, false); }
 V3Number& V3Number::opAssignNonXZ(const V3Number& lhs, bool ignoreXZ) {
     // Note may be a width change during the assign.

src/V3Number.h

@@ -564,7 +564,6 @@ private:
         }
     }
     static string displayPad(size_t fmtsize, char pad, bool left, const string& in) VL_PURE;
-    string displayed(FileLine* fl, const string& vformat) const VL_MT_STABLE;
     string displayed(const string& vformat) const VL_MT_STABLE {
         return displayed(m_fileline, vformat);
     }
@@ -592,6 +591,7 @@ public:
     // ACCESSORS
     string ascii(bool prefixed = true, bool cleanVerilog = false) const VL_MT_STABLE;
     string displayed(AstNode* nodep, const string& vformat) const VL_MT_STABLE;
+    string displayed(FileLine* fl, const string& vformat) const VL_MT_STABLE;
     static bool displayedFmtLegal(char format, bool isScan);  // Is this a valid format letter?
     int width() const VL_MT_SAFE { return m_data.width(); }
     int widthToFit() const;  // Minimum width that can represent this number (~== log2(num)+1)
@@ -716,6 +716,7 @@ public:
     V3Number& opWildEq(const V3Number& lhs, const V3Number& rhs);
     V3Number& opWildNeq(const V3Number& lhs, const V3Number& rhs);
     V3Number& opBufIf1(const V3Number& ens, const V3Number& if1s);
+    V3Number& opSetRange(uint32_t lsb, uint32_t width, char bitValue);
     // "standard" math
     V3Number& opNot(const V3Number& lhs);
     V3Number& opLogNot(const V3Number& lhs);

src/V3Options.cpp

@@ -1803,8 +1803,10 @@ void V3Options::parseOptsList(FileLine* fl, const string& optdir, int argc,
     DECL_OPTION("-Wwarn-UNSUPPORTED", CbCall, []() {
         FileLine::globalWarnOff(V3ErrorCode::E_UNSUPPORTED, false);
         FileLine::globalWarnOff(V3ErrorCode::COVERIGN, false);
+        FileLine::globalWarnOff(V3ErrorCode::SPECIFYIGN, false);
         V3Error::pretendError(V3ErrorCode::E_UNSUPPORTED, false);
         V3Error::pretendError(V3ErrorCode::COVERIGN, false);
+        V3Error::pretendError(V3ErrorCode::SPECIFYIGN, false);
     });
     DECL_OPTION("-Wwarn-WIDTH", CbCall, []() {
         FileLine::globalWarnOff(V3ErrorCode::WIDTH, false);

src/V3Param.cpp

@@ -1116,7 +1116,7 @@ class ParamVisitor final : public VNVisitor {
                 } else {
                     cellp->v3fatalSrc("Expected module parameterization");
                 }
-                UASSERT_OBJ(srcModp, cellp, "Unlinked class ref");
+                if (!srcModp) continue;
 
                 // Update path
                 string someInstanceName = modp->someInstanceName();

src/V3ParseImp.h

@@ -293,12 +293,12 @@ public:
     void dumpInputsFile() VL_MT_DISABLED;
     void dumpTokensAhead(int line) VL_MT_DISABLED;
     static void candidatePli(VSpellCheck* spellerp) VL_MT_DISABLED;
+    void importIfInStd(FileLine* fileline, const string& id);
 
 private:
     void preprocDumps(std::ostream& os);
     void lexFile(const string& modname) VL_MT_DISABLED;
     void yylexReadTok() VL_MT_DISABLED;
-    void importIfInStd(FileLine* fileline, const string& id);
     void tokenPull() VL_MT_DISABLED;
     void tokenPipeline() VL_MT_DISABLED;  // Internal; called from tokenToBison
     int tokenPipelineId(int token) VL_MT_DISABLED;

src/V3Randomize.cpp

@@ -2198,14 +2198,14 @@ class RandomizeVisitor final : public VNVisitor {
 
         AstClass* classp = nullptr;
         if (AstMethodCall* const callp = VN_CAST(nodep, MethodCall)) {
-            UASSERT_OBJ(callp->fromp()->dtypep(), callp->fromp(), "Object dtype is not linked");
-            AstClassRefDType* const classrefdtypep
-                = VN_CAST(callp->fromp()->dtypep(), ClassRefDType);
-            if (!classrefdtypep) {
-                nodep->v3warn(E_UNSUPPORTED,
-                              "Inline constraints are not supported for this node type");
-                return;
-            }
+            const AstNodeDType* const fromDTypep = callp->fromp()->dtypep();
+            UASSERT_OBJ(fromDTypep, callp->fromp(), "Object dtype is not linked");
+            const AstClassRefDType* const classrefdtypep
+                = VN_CAST(fromDTypep->skipRefp(), ClassRefDType);
+            UASSERT_OBJ(classrefdtypep, callp->fromp(),
+                        "Randomize called on expression of non-class type "
+                            << fromDTypep->skipRefp()->prettyDTypeNameQ()
+                            << " (it should be detected earlier)");
             classp = classrefdtypep->classp();
             UASSERT_OBJ(classp, classrefdtypep, "Class type is unlinked to its ref type");
         } else {

src/V3Sched.cpp

@@ -104,6 +104,17 @@ void invertAndMergeSenTreeMap(
     for (const auto& pair : senTreeMap) result.emplace(pair.second, pair.first);
 }
 
+AstSenTree* findTriggeredIface(const AstVarScope* vscp,
+                               const VirtIfaceTriggers::IfaceSensMap& vifTrigged,
+                               const VirtIfaceTriggers::IfaceMemberSensMap& vifMemberTriggered) {
+    const auto ifaceIt = vifTrigged.find(vscp->varp()->sensIfacep());
+    if (ifaceIt != vifTrigged.end()) return ifaceIt->second;
+    for (const auto& memberIt : vifMemberTriggered) {
+        if (memberIt.first.m_ifacep == vscp->varp()->sensIfacep()) { return memberIt.second; }
+    }
+    return nullptr;
+}
+
 //============================================================================
 // Code generation utility functions
 
@@ -955,8 +966,10 @@ AstNode* createInputCombLoop(AstNetlist* netlistp, AstCFunc* const initFuncp,
     AstSenTree* const dpiExportTriggered
         = dpiExportTriggerVscp ? createTriggerSenTree(netlistp, trig.m_vscp, dpiExportTriggerIndex)
                                : nullptr;
-    const auto& vifTriggered
+    const auto& vifTriggeredIco
         = virtIfaceTriggers.makeIfaceToSensMap(netlistp, firstVifTriggerIndex, trig.m_vscp);
+    const auto& vifMemberTriggeredIco
+        = virtIfaceTriggers.makeMemberToSensMap(netlistp, firstVifTriggerIndex, trig.m_vscp);
 
     // Create and Order the body function
     AstCFunc* const icoFuncp
@@ -968,8 +981,9 @@ AstNode* createInputCombLoop(AstNetlist* netlistp, AstCFunc* const initFuncp,
                              }
                              if (varp->isWrittenByDpi()) out.push_back(dpiExportTriggered);
                              if (vscp->varp()->sensIfacep()) {
-                                 const auto it = vifTriggered.find(vscp->varp()->sensIfacep());
-                                 if (it != vifTriggered.end()) out.push_back(it->second);
+                                 AstSenTree* ifaceTriggered = findTriggeredIface(
+                                     vscp, vifTriggeredIco, vifMemberTriggeredIco);
+                                 out.push_back(ifaceTriggered);
                              }
                          });
     splitCheck(icoFuncp);
@@ -1189,6 +1203,18 @@ VirtIfaceTriggers::makeIfaceToSensMap(AstNetlist* const netlistp, size_t vifTrig
     return ifaceToSensMap;
 }
 
+VirtIfaceTriggers::IfaceMemberSensMap
+VirtIfaceTriggers::makeMemberToSensMap(AstNetlist* const netlistp, size_t vifTriggerIndex,
+                                       AstVarScope* trigVscp) const {
+    IfaceMemberSensMap memberToSensMap;
+    for (const auto& p : m_memberTriggers) {
+        memberToSensMap.emplace(
+            std::make_pair(p.first, createTriggerSenTree(netlistp, trigVscp, vifTriggerIndex)));
+        ++vifTriggerIndex;
+    }
+    return memberToSensMap;
+}
+
 //============================================================================
 // Top level entry-point to scheduling
 
@@ -1359,6 +1385,8 @@ void schedule(AstNetlist* netlistp) {
 
     const auto& vifTriggeredAct
         = virtIfaceTriggers.makeIfaceToSensMap(netlistp, firstVifTriggerIndex, actTrig.m_vscp);
+    const auto& vifMemberTriggeredAct
+        = virtIfaceTriggers.makeMemberToSensMap(netlistp, firstVifTriggerIndex, actTrig.m_vscp);
 
     AstCFunc* const actFuncp = V3Order::order(
         netlistp, {&logicRegions.m_pre, &logicRegions.m_act, &logicReplicas.m_act}, trigToSenAct,
@@ -1367,8 +1395,9 @@ void schedule(AstNetlist* netlistp) {
             if (it != actTimingDomains.end()) out = it->second;
             if (vscp->varp()->isWrittenByDpi()) out.push_back(dpiExportTriggeredAct);
             if (vscp->varp()->sensIfacep()) {
-                const auto sit = vifTriggeredAct.find(vscp->varp()->sensIfacep());
-                if (sit != vifTriggeredAct.end()) out.push_back(sit->second);
+                AstSenTree* ifaceTriggered
+                    = findTriggeredIface(vscp, vifTriggeredAct, vifMemberTriggeredAct);
+                out.push_back(ifaceTriggered);
             }
         });
     splitCheck(actFuncp);
@@ -1396,6 +1425,8 @@ void schedule(AstNetlist* netlistp) {
                   : nullptr;
         const auto& vifTriggered
             = virtIfaceTriggers.makeIfaceToSensMap(netlistp, firstVifTriggerIndex, trigVscp);
+        const auto& vifMemberTriggered
+            = virtIfaceTriggers.makeMemberToSensMap(netlistp, firstVifTriggerIndex, trigVscp);
 
         const auto& timingDomains = timingKit.remapDomains(trigMap);
         AstCFunc* const funcp = V3Order::order(
@@ -1405,8 +1436,9 @@ void schedule(AstNetlist* netlistp) {
                 if (it != timingDomains.end()) out = it->second;
                 if (vscp->varp()->isWrittenByDpi()) out.push_back(dpiExportTriggered);
                 if (vscp->varp()->sensIfacep()) {
-                    const auto sit = vifTriggered.find(vscp->varp()->sensIfacep());
-                    if (sit != vifTriggered.end()) out.push_back(sit->second);
+                    AstSenTree* ifaceTriggered
+                        = findTriggeredIface(vscp, vifTriggered, vifMemberTriggered);
+                    out.push_back(ifaceTriggered);
                 }
             });
 

src/V3Sched.h

@@ -153,17 +153,55 @@ public:
 };
 
 class VirtIfaceTriggers final {
+    // Represents a specific member in a virtual interface
+    struct IfaceMember final {
+        const AstIface* m_ifacep;  // Interface type
+        const AstVar* m_memberVarp;  // pointer to member field
+
+        IfaceMember(const AstIface* ifacep, const AstVar* memberVarp)
+            : m_ifacep(ifacep)
+            , m_memberVarp(memberVarp) {}
+
+        bool operator<(const IfaceMember& other) const {
+            if (m_ifacep != other.m_ifacep) return m_ifacep < other.m_ifacep;
+            return m_memberVarp < other.m_memberVarp;
+        }
+    };
+
+public:
+    using IfaceMemberTrigger = std::pair<IfaceMember, AstVarScope*>;
+    using IfaceMemberTriggerVec = std::vector<IfaceMemberTrigger>;
+    using IfaceMemberSensMap = std::map<IfaceMember, AstSenTree*>;
+
     using IfaceTrigger = std::pair<const AstIface*, AstVarScope*>;
     using IfaceTriggerVec = std::vector<IfaceTrigger>;
     using IfaceSensMap = std::map<const AstIface*, AstSenTree*>;
-    IfaceTriggerVec m_triggers;
 
-public:
-    void emplace_back(IfaceTrigger&& p) { m_triggers.emplace_back(std::move(p)); }
-    IfaceTriggerVec::const_iterator begin() const { return m_triggers.begin(); }
-    IfaceTriggerVec::const_iterator end() const { return m_triggers.end(); }
+    IfaceMemberTriggerVec m_memberTriggers;
+    IfaceTriggerVec m_ifaceTriggers;
+
+    void addMemberTrigger(const AstIface* ifacep, const AstVar* memberVarp,
+                          AstVarScope* triggerVscp) {
+        m_memberTriggers.emplace_back(IfaceMember(ifacep, memberVarp), triggerVscp);
+    }
+
+    AstVarScope* findMemberTrigger(const AstIface* ifacep, const AstVar* memberVarp) const {
+        IfaceMember target{ifacep, memberVarp};
+        for (const auto& pair : m_memberTriggers) {
+            if (!(pair.first < target) && !(target < pair.first)) return pair.second;
+        }
+        return nullptr;
+    }
+
+    IfaceMemberSensMap makeMemberToSensMap(AstNetlist* netlistp, size_t vifTriggerIndex,
+                                           AstVarScope* trigVscp) const;
+
+    void emplace_back(IfaceTrigger&& p) { m_ifaceTriggers.emplace_back(std::move(p)); }
+    IfaceTriggerVec::const_iterator begin() const { return m_ifaceTriggers.begin(); }
+    IfaceTriggerVec::const_iterator end() const { return m_ifaceTriggers.end(); }
     IfaceSensMap makeIfaceToSensMap(AstNetlist* netlistp, size_t vifTriggerIndex,
                                     AstVarScope* trigVscp) const;
+
     VL_UNCOPYABLE(VirtIfaceTriggers);
     VirtIfaceTriggers() = default;
     VirtIfaceTriggers(VirtIfaceTriggers&&) = default;

src/V3SchedVirtIface.cpp

@@ -49,12 +49,15 @@ private:
 
     // TYPES
     using OnWriteToVirtIface = std::function<void(AstVarRef*, AstIface*)>;
+    using OnWriteToVirtIfaceMember
+        = std::function<void(AstVarRef*, AstIface*, const std::string&)>;
 
     // STATE
     AstNetlist* const m_netlistp;  // Root node
     AstAssign* m_trigAssignp = nullptr;  // Previous/current trigger assignment
     AstIface* m_trigAssignIfacep = nullptr;  // Interface type whose trigger is assigned
                                              // by m_trigAssignp
+    AstVar* m_trigAssignMemberVarp;  // Member pointer whose trigger is assigned
     V3UniqueNames m_vifTriggerNames{"__VvifTrigger"};  // Unique names for virt iface
                                                        // triggers
     VirtIfaceTriggers m_triggers;  // Interfaces and corresponding trigger vars
@@ -73,6 +76,25 @@ private:
             }
         });
     }
+    // For each write across a virtual interface boundary (member-level tracking)
+    static void foreachWrittenVirtIfaceMember(
+        AstNode* const nodep, const std::function<void(AstVarRef*, AstIface*, AstVar*)>& onWrite) {
+        nodep->foreach([&](AstVarRef* const refp) {
+            if (refp->access().isReadOnly()) return;
+            if (AstIfaceRefDType* const dtypep = VN_CAST(refp->varp()->dtypep(), IfaceRefDType)) {
+                if (dtypep->isVirtual()) {
+                    if (AstMemberSel* const memberSelp = VN_CAST(refp->firstAbovep(), MemberSel)) {
+                        // Extract the member varp from the MemberSel node
+                        AstVar* memberVarp = memberSelp->varp();
+                        onWrite(refp, dtypep->ifacep(), memberVarp);
+                    }
+                }
+            } else if (AstIface* const ifacep = refp->varp()->sensIfacep()) {
+                AstVar* memberVarp = refp->varp();
+                onWrite(refp, ifacep, memberVarp);
+            }
+        });
+    }
     // Returns true if there is a write across a virtual interface boundary
     static bool writesToVirtIface(const AstNode* const nodep) {
         return nodep->exists([](const AstVarRef* const refp) {
@@ -103,12 +125,31 @@ private:
         return new AstVarRef{flp, VN_AS(ifacep->user1p(), VarScope), VAccess::WRITE};
     }
 
+    // Create trigger reference for a specific interface member
+    AstVarRef* createVirtIfaceMemberTriggerRefp(FileLine* const flp, AstIface* ifacep,
+                                                const AstVar* memberVarp) {
+        // Check if we already have a trigger for this specific member
+        AstVarScope* existingTrigger = m_triggers.findMemberTrigger(ifacep, memberVarp);
+        if (!existingTrigger) {
+            AstScope* const scopeTopp = m_netlistp->topScopep()->scopep();
+            // Create a unique name for this member trigger
+            const std::string triggerName
+                = m_vifTriggerNames.get(ifacep) + "_Vtrigm_" + memberVarp->name();
+            AstVarScope* const vscp = scopeTopp->createTemp(triggerName, 1);
+            m_triggers.addMemberTrigger(ifacep, memberVarp, vscp);
+            existingTrigger = vscp;
+        }
+        return new AstVarRef{flp, existingTrigger, VAccess::WRITE};
+    }
+
     // VISITORS
     void visit(AstNodeProcedure* nodep) override {
         VL_RESTORER(m_trigAssignp);
         m_trigAssignp = nullptr;
         VL_RESTORER(m_trigAssignIfacep);
         m_trigAssignIfacep = nullptr;
+        VL_RESTORER(m_trigAssignMemberVarp);
+        m_trigAssignMemberVarp = nullptr;
         iterateChildren(nodep);
     }
     void visit(AstCFunc* nodep) override {
@@ -116,6 +157,8 @@ private:
         m_trigAssignp = nullptr;
         VL_RESTORER(m_trigAssignIfacep);
         m_trigAssignIfacep = nullptr;
+        VL_RESTORER(m_trigAssignMemberVarp);
+        m_trigAssignMemberVarp = nullptr;
         iterateChildren(nodep);
     }
     void visit(AstAssignW* nodep) override {
@@ -140,11 +183,13 @@ private:
         {
             VL_RESTORER(m_trigAssignp);
             VL_RESTORER(m_trigAssignIfacep);
+            VL_RESTORER(m_trigAssignMemberVarp);
             iterateAndNextNull(nodep->thensp());
         }
         {
             VL_RESTORER(m_trigAssignp);
             VL_RESTORER(m_trigAssignIfacep);
+            VL_RESTORER(m_trigAssignMemberVarp);
             iterateAndNextNull(nodep->elsesp());
         }
         if (v3Global.usesTiming()) {
@@ -152,6 +197,7 @@ private:
             // branch
             m_trigAssignp = nullptr;
             m_trigAssignIfacep = nullptr;
+            m_trigAssignMemberVarp = nullptr;
         }
     }
     void visit(AstWhile* nodep) override {
@@ -161,18 +207,21 @@ private:
         {
             VL_RESTORER(m_trigAssignp);
             VL_RESTORER(m_trigAssignIfacep);
+            VL_RESTORER(m_trigAssignMemberVarp);
             iterateAndNextNull(nodep->stmtsp());
         }
         if (v3Global.usesTiming()) {
             // Clear the trigger assignment, as there could have been timing controls in the loop
             m_trigAssignp = nullptr;
             m_trigAssignIfacep = nullptr;
+            m_trigAssignMemberVarp = nullptr;
         }
     }
     void visit(AstJumpBlock* nodep) override {
         {
             VL_RESTORER(m_trigAssignp);
             VL_RESTORER(m_trigAssignIfacep);
+            VL_RESTORER(m_trigAssignMemberVarp);
             iterateChildren(nodep);
         }
         if (v3Global.usesTiming()) {
@@ -180,29 +229,48 @@ private:
             // block
             m_trigAssignp = nullptr;
             m_trigAssignIfacep = nullptr;
+            m_trigAssignMemberVarp = nullptr;
         }
     }
     void visit(AstNodeStmt* nodep) override {
         if (v3Global.usesTiming()
             && nodep->exists([](AstNode* nodep) { return nodep->isTimingControl(); })) {
-            m_trigAssignp = nullptr;  // Could be after a delay - need new trigger assignment
+            m_trigAssignp = nullptr;
             m_trigAssignIfacep = nullptr;
-            // No restorer, as following statements should not reuse the old assignment
+            m_trigAssignMemberVarp = nullptr;
         }
         FileLine* const flp = nodep->fileline();
-        foreachWrittenVirtIface(nodep, [&](AstVarRef*, AstIface* ifacep) {
-            if (ifacep != m_trigAssignIfacep) {
-                // Write to different interface type than before - need new trigger assignment
-                // No restorer, as following statements should not reuse the old assignment
+
+        foreachWrittenVirtIfaceMember(nodep, [&](AstVarRef*, AstIface* ifacep,
+                                                 AstVar* memberVarp) {
+            if (ifacep != m_trigAssignIfacep || memberVarp != m_trigAssignMemberVarp) {
+                // Write to different interface member than before - need new trigger assignment
                 m_trigAssignIfacep = ifacep;
+                m_trigAssignMemberVarp = memberVarp;
                 m_trigAssignp = nullptr;
             }
             if (!m_trigAssignp) {
-                m_trigAssignp = new AstAssign{flp, createVirtIfaceTriggerRefp(flp, ifacep),
-                                              new AstConst{flp, AstConst::BitTrue{}}};
+                m_trigAssignp
+                    = new AstAssign{flp, createVirtIfaceMemberTriggerRefp(flp, ifacep, memberVarp),
+                                    new AstConst{flp, AstConst::BitTrue{}}};
                 nodep->addNextHere(m_trigAssignp);
             }
         });
+        // Fallback to whole-interface tracking if no member-specific assignments found
+        if (!m_trigAssignp) {
+            foreachWrittenVirtIface(nodep, [&](AstVarRef*, AstIface* ifacep) {
+                if (ifacep != m_trigAssignIfacep) {
+                    m_trigAssignIfacep = ifacep;
+                    m_trigAssignMemberVarp = nullptr;
+                    m_trigAssignp = nullptr;
+                }
+                if (!m_trigAssignp) {
+                    m_trigAssignp = new AstAssign{flp, createVirtIfaceTriggerRefp(flp, ifacep),
+                                                  new AstConst{flp, AstConst::BitTrue{}}};
+                    nodep->addNextHere(m_trigAssignp);
+                }
+            });
+        }
     }
     void visit(AstNodeExpr*) override {}  // Accelerate
     void visit(AstNode* nodep) override { iterateChildren(nodep); }

src/V3StatsReport.cpp

@@ -215,7 +215,7 @@ void V3Stats::statsStage(const string& name) {
     V3Stats::addStatPerf("Stage, Elapsed time (sec), " + digitName, wallTimeDelta);
     V3Stats::addStatPerf("Stage, Elapsed time (sec), TOTAL", wallTimeDelta);
 
-    const double memory = VlOs::memUsageBytes() / 1024.0 / 1024.0;
+    const double memory = VlOs::memPeakUsageBytes() / 1024.0 / 1024.0;
     V3Stats::addStatPerf("Stage, Memory (MB), " + digitName, memory);
 }
 
@@ -266,7 +266,7 @@ void V3Stats::summaryReport() {
               << ", cvt=" << walltimeCvt << ", bld=" << walltimeBuild << "); cpu " << cputime
               << " s on " << std::max(v3Global.opt.verilateJobs(), v3Global.opt.buildJobs())
               << " threads";
-    const double memory = VlOs::memUsageBytes() / 1024.0 / 1024.0;
+    const double memory = VlOs::memPeakUsageBytes() / 1024.0 / 1024.0;
     if (VL_UNCOVERABLE(memory != 0.0)) std::cout << "; alloced " << memory << " MB";
     std::cout << "\n";
 }

src/V3Unroll.cpp

@@ -46,6 +46,7 @@ class UnrollVisitor final : public VNVisitor {
     bool m_varModeCheck;  // Just checking RHS assignments
     bool m_varModeReplace;  // Replacing varrefs
     bool m_varAssignHit;  // Assign var hit
+    bool m_forkHit;  // Fork hit
     bool m_generate;  // Expand single generate For loop
     string m_beginName;  // What name to give begin iterations
     VDouble0 m_statLoops;  // Statistic tracking
@@ -133,6 +134,7 @@ class UnrollVisitor final : public VNVisitor {
         // Now, make sure there's no assignment to this variable in the loop
         m_varModeCheck = true;
         m_varAssignHit = false;
+        m_forkHit = false;
         m_ignoreIncp = incp;
         iterateAndNextNull(precondsp);
         iterateAndNextNull(bodysp);
@@ -141,6 +143,8 @@ class UnrollVisitor final : public VNVisitor {
         m_ignoreIncp = nullptr;
         if (m_varAssignHit) return cantUnroll(nodep, "genvar assigned *inside* loop");
 
+        if (m_forkHit) return cantUnroll(nodep, "fork inside loop");
+
         //
         if (m_forVscp) {
             UINFO(8, "   Loop Variable: " << m_forVscp);
@@ -463,6 +467,17 @@ class UnrollVisitor final : public VNVisitor {
         }
     }
 
+    void visit(AstFork* nodep) override {
+        if (m_varModeCheck) {
+            if (nodep->joinType().joinNone() || nodep->joinType().joinAny()) {
+                // Forks are not allowed to unroll for loops, so we just set a flag
+                m_forkHit = true;
+            }
+        } else {
+            iterateChildren(nodep);
+        }
+    }
+
     //--------------------
     // Default: Just iterate
     void visit(AstNode* nodep) override {
@@ -489,6 +504,7 @@ public:
         m_varModeCheck = false;
         m_varModeReplace = false;
         m_varAssignHit = false;
+        m_forkHit = false;
         m_generate = generate;
         m_beginName = beginName;
     }

src/V3Width.cpp

@@ -629,8 +629,8 @@ class WidthVisitor final : public VNVisitor {
                 iterateCheckString(nodep, "RHS", nodep->rhsp(), BOTH);
                 nodep->dtypeSetString();
             } else {
-                iterateCheckSelf(nodep, "LHS", nodep->lhsp(), SELF, BOTH);
-                iterateCheckSelf(nodep, "RHS", nodep->rhsp(), SELF, BOTH);
+                iterateCheckIntegralSelf(nodep, "LHS", nodep->lhsp(), SELF, BOTH);
+                iterateCheckIntegralSelf(nodep, "RHS", nodep->rhsp(), SELF, BOTH);
 
                 if (m_streamConcat) {
                     packIfUnpacked(nodep->lhsp());
@@ -837,7 +837,7 @@ class WidthVisitor final : public VNVisitor {
             if (vdtypep && vdtypep->isString()) {
                 iterateCheckString(nodep, "LHS", nodep->srcp(), BOTH);
             } else {
-                iterateCheckSelf(nodep, "LHS", nodep->srcp(), SELF, BOTH);
+                iterateCheckIntegralSelf(nodep, "LHS", nodep->srcp(), SELF, BOTH);
             }
 
             if ((vdtypep && vdtypep->isString()) || nodep->srcp()->isString()) {
@@ -971,7 +971,7 @@ class WidthVisitor final : public VNVisitor {
             if (debug() >= 9) nodep->dumpTree("-  selWidth: ");
             userIterateAndNext(nodep->fromp(), WidthVP{CONTEXT_DET, PRELIM}.p());
             userIterateAndNext(nodep->lsbp(), WidthVP{SELF, PRELIM}.p());
-            checkCvtUS(nodep->fromp());
+            checkCvtUS(nodep->fromp(), false);
             iterateCheckSizedSelf(nodep, "Select LHS", nodep->fromp(), SELF, BOTH);
             int width = nodep->widthConst();
             if (width <= 0) {
@@ -1510,7 +1510,7 @@ class WidthVisitor final : public VNVisitor {
                 return;
             }
 
-            checkCvtUS(nodep->lhsp());
+            checkCvtUS(nodep->lhsp(), false);
             iterateCheckSizedSelf(nodep, "RHS", nodep->rhsp(), SELF, BOTH);
             nodep->dtypeFrom(nodep->lhsp());
         }
@@ -2422,6 +2422,18 @@ class WidthVisitor final : public VNVisitor {
             nodep->dtypeSetLogicSized(1, bdtypep->numeric());
             VL_DANGLING(bdtypep);
         }
+        if (nodep->isNet()) {
+            AstNodeDType* const badDtp = dtypeNot4StateIntegralRecurse(nodep->dtypep());
+            if (badDtp)
+                nodep->v3error(
+                    "Net " << nodep->prettyNameQ()
+                           << " data type must be 4-state integral or array/union/struct of such"
+                           << " (IEEE 1800-2023 6.7.1)\n"
+                           << nodep->warnContextPrimary() << '\n'
+                           << badDtp->warnOther() << "... Location of failing data type "
+                           << badDtp->prettyDTypeNameQ() << '\n'
+                           << badDtp->warnContextSecondary());
+        }
         if (nodep->valuep() && !didchk) {
             // if (debug()) nodep->dumpTree("-  final: ");
             // AstPattern requires assignments to pass datatype on PRELIM
@@ -2483,10 +2495,15 @@ class WidthVisitor final : public VNVisitor {
         UINFO(5, "  ENUMDTYPE " << nodep);
         nodep->refDTypep(iterateEditMoveDTypep(nodep, nodep->subDTypep()));
         nodep->dtypep(nodep);
-        AstBasicDType* basicp = nodep->dtypep()->skipRefp()->basicp();
-        if (!basicp || !basicp->keyword().isIntNumeric()) {
+        AstNodeDType* basicp = nodep->dtypep()->skipRefp()->basicp();
+        AstNodeDType* const badDtp = dtypeNotIntAtomOrVecRecurse(nodep->subDTypep());
+        if (badDtp) {
             nodep->v3error(
-                "Enum type must be an integer atom or vector type (IEEE 1800-2023 6.19)");
+                "Enum data type must be an integer atom or vector type (IEEE 1800-2023 6.19)\n"
+                << nodep->warnContextPrimary() << '\n'
+                << badDtp->warnOther() << "... Location of failing data type "
+                << badDtp->prettyDTypeNameQ() << '\n'
+                << badDtp->warnContextSecondary());
             basicp = nodep->findSigned32DType()->basicp();
             nodep->refDTypep(basicp);
         }
@@ -2553,9 +2570,16 @@ class WidthVisitor final : public VNVisitor {
             // Default type is int, but common to assign narrower values, so minwidth from value
             userIterateAndNext(nodep->valuep(), WidthVP{CONTEXT_DET, PRELIM}.p());
             bool warnOn = true;
-            if (const AstConst* const constp = VN_CAST(nodep->valuep(), Const)) {
+            AstNodeExpr* valuep = nodep->valuep();
+            if (const AstAdd* const anodep = VN_CAST(valuep, Add)) {
+                // If constructed by V3LinkParse due to "enumitem[N_REPEATS] value"
+                if (anodep->fileline()->equalFirstLineCol(*(nodep->fileline())))
+                    valuep = anodep->lhsp();
+            }
+            if (const AstConst* const constp = VN_CAST(valuep, Const)) {
                 if (static_cast<int>(constp->num().mostSetBitP1()) > nodep->width()) {
-                    constp->v3error("Enum value exceeds width of enum type (IEEE 1800-2023 6.19)");
+                    constp->v3warn(ENUMITEMWIDTH,
+                                   "Enum value exceeds width of enum type (IEEE 1800-2023 6.19)");
                     warnOn = false;  // Prevent normal WIDTHTRUNC
                 }
             }
@@ -6819,7 +6843,7 @@ class WidthVisitor final : public VNVisitor {
         UASSERT_OBJ(!nodep->op2p(), nodep, "For unary ops only!");
         if (m_vup->prelim()) {
             userIterateAndNext(nodep->lhsp(), WidthVP{CONTEXT_DET, PRELIM}.p());
-            if (!real_ok) checkCvtUS(nodep->lhsp());
+            if (!real_ok) checkCvtUS(nodep->lhsp(), false);
         }
         if (real_ok && nodep->lhsp()->isDouble()) {
             spliceCvtD(nodep->lhsp());
@@ -6860,7 +6884,7 @@ class WidthVisitor final : public VNVisitor {
         UASSERT_OBJ(!nodep->op2p(), nodep, "For unary ops only!");
         if (m_vup->prelim()) {
             userIterateAndNext(nodep->lhsp(), WidthVP{SELF, PRELIM}.p());
-            checkCvtUS(nodep->lhsp());
+            checkCvtUS(nodep->lhsp(), true);
             const int width = nodep->lhsp()->width();
             AstNodeDType* const expDTypep = nodep->findLogicDType(width, width, rs_out);
             nodep->dtypep(expDTypep);
@@ -6888,7 +6912,7 @@ class WidthVisitor final : public VNVisitor {
         //   RHS is self-determined. RHS is always treated as unsigned, has no effect on result.
         if (m_vup->prelim()) {
             userIterateAndNext(nodep->lhsp(), WidthVP{SELF, PRELIM}.p());
-            checkCvtUS(nodep->lhsp());
+            checkCvtUS(nodep->lhsp(), false);
             iterateCheckSizedSelf(nodep, "RHS", nodep->rhsp(), SELF, BOTH);
             nodep->dtypeFrom(nodep->lhsp());
         }
@@ -6948,8 +6972,8 @@ class WidthVisitor final : public VNVisitor {
             // Determine expression widths only relying on what's in the subops
             userIterateAndNext(nodep->lhsp(), WidthVP{CONTEXT_DET, PRELIM}.p());
             userIterateAndNext(nodep->rhsp(), WidthVP{CONTEXT_DET, PRELIM}.p());
-            checkCvtUS(nodep->lhsp());
-            checkCvtUS(nodep->rhsp());
+            checkCvtUS(nodep->lhsp(), false);
+            checkCvtUS(nodep->rhsp(), false);
             const int width = std::max(nodep->lhsp()->width(), nodep->rhsp()->width());
             const int mwidth = std::max(nodep->lhsp()->widthMin(), nodep->rhsp()->widthMin());
             const bool expSigned = (nodep->lhsp()->isSigned() && nodep->rhsp()->isSigned());
@@ -6983,8 +7007,8 @@ class WidthVisitor final : public VNVisitor {
             userIterateAndNext(nodep->lhsp(), WidthVP{CONTEXT_DET, PRELIM}.p());
             userIterateAndNext(nodep->rhsp(), WidthVP{CONTEXT_DET, PRELIM}.p());
             if (!real_ok) {
-                checkCvtUS(nodep->lhsp());
-                checkCvtUS(nodep->rhsp());
+                checkCvtUS(nodep->lhsp(), false);
+                checkCvtUS(nodep->rhsp(), false);
             }
             if (nodep->lhsp()->isDouble() || nodep->rhsp()->isDouble()) {
                 spliceCvtD(nodep->lhsp());
@@ -7323,8 +7347,12 @@ class WidthVisitor final : public VNVisitor {
         }
         (void)underp;  // cppcheck
     }
+    void iterateCheckIntegralSelf(AstNode* nodep, const char* side, AstNode* underp, Determ determ,
+                                  Stage stage) {
+        iterateCheckSelf(nodep, side, underp, determ, stage, true);
+    }
     void iterateCheckSelf(AstNode* nodep, const char* side, AstNode* underp, Determ determ,
-                          Stage stage) {
+                          Stage stage, bool integralOnly = false) {
         // Coerce child to any data type; child is self-determined
         // i.e. isolated from expected type.
         // e.g. nodep=CONCAT, underp=lhs in CONCAT(lhs,rhs)
@@ -7334,7 +7362,8 @@ class WidthVisitor final : public VNVisitor {
         if (stage & PRELIM) {
             underp = userIterateSubtreeReturnEdits(underp, WidthVP{SELF, PRELIM}.p());
         }
-        underp = VN_IS(underp, NodeExpr) ? checkCvtUS(VN_AS(underp, NodeExpr)) : underp;
+        underp
+            = VN_IS(underp, NodeExpr) ? checkCvtUS(VN_AS(underp, NodeExpr), integralOnly) : underp;
         AstNodeDType* const expDTypep = underp->dtypep();
         underp = iterateCheck(nodep, side, underp, SELF, FINAL, expDTypep, EXTEND_EXP);
         (void)underp;  // cppcheck
@@ -7350,7 +7379,7 @@ class WidthVisitor final : public VNVisitor {
         if (stage & PRELIM) {
             underp = userIterateSubtreeReturnEdits(underp, WidthVP{SELF, PRELIM}.p());
         }
-        underp = VN_IS(underp, NodeExpr) ? checkCvtUS(VN_AS(underp, NodeExpr)) : underp;
+        underp = VN_IS(underp, NodeExpr) ? checkCvtUS(VN_AS(underp, NodeExpr), false) : underp;
         AstNodeDType* const expDTypep = underp->dtypep();
         underp = iterateCheck(nodep, side, underp, SELF, FINAL, expDTypep, EXTEND_EXP);
         AstNodeDType* const checkDtp = expDTypep->skipRefToEnump();
@@ -7667,12 +7696,16 @@ class WidthVisitor final : public VNVisitor {
     //----------------------------------------------------------------------
     // SIGNED/DOUBLE METHODS
 
-    AstNodeExpr* checkCvtUS(AstNodeExpr* nodep) {
-        if (nodep && nodep->isDouble()) {
-            nodep->v3error("Expected integral (non-" << nodep->dtypep()->prettyDTypeNameQ()
-                                                     << ") input to "
-                                                     << nodep->backp()->prettyTypeName());
-            nodep = spliceCvtS(nodep, true, 32);
+    AstNodeExpr* checkCvtUS(AstNodeExpr* nodep, bool fatal) {
+        if (nodep && nodep->dtypep()->skipRefp()->isDouble()) {
+            if (fatal) {
+                nodep->v3error("Expected integral input to " << nodep->backp()->prettyTypeName());
+            } else {
+                nodep->v3warn(REALCVT,
+                              "Implicit conversion of real to integer; expected integral input to "
+                                  << nodep->backp()->prettyTypeName());
+            }
+            nodep = spliceCvtS(nodep, false, 32);
         }
         return nodep;
     }
@@ -8293,6 +8326,39 @@ class WidthVisitor final : public VNVisitor {
         if (nodep->subDTypep()) return hasOpenArrayIterateDType(nodep->subDTypep()->skipRefp());
         return false;
     }
+    AstNodeDType* dtypeNotIntAtomOrVecRecurse(AstNodeDType* nodep, bool ranged = false) {
+        // If node is _not_ integer or atomic, return node that makes it fail
+        nodep = nodep->skipRefToEnump();
+        if (AstBasicDType* const dtp = VN_CAST(nodep, BasicDType)) {
+            if (ranged && (!dtp->isBitLogic() || dtp->isRanged()))
+                return dtp;  // Packed when already packed
+            if (dtp->keyword().isIntNumeric()) return nullptr;
+            return dtp;
+        } else if (AstPackArrayDType* const dtp = VN_CAST(nodep, PackArrayDType)) {
+            if (ranged) return dtp;  // Packed when already packed
+            return dtypeNotIntAtomOrVecRecurse(nodep->subDTypep(), true);
+        }
+        return nodep;
+    }
+    AstNodeDType* dtypeNot4StateIntegralRecurse(AstNodeDType* nodep) {
+        // If node is _not_ inet valid data type, 4-state integral packed or union, return node
+        // that makes it fail
+        nodep = nodep->skipRefp();
+        if (AstBasicDType* const dtp = VN_CAST(nodep, BasicDType)) {
+            if (!dtp->keyword().isFourstate()) return dtp;
+            return nullptr;
+        } else if (AstNodeArrayDType* const dtp = VN_CAST(nodep, NodeArrayDType)) {
+            return dtypeNot4StateIntegralRecurse(dtp->subDTypep());
+        } else if (AstNodeUOrStructDType* const dtp = VN_CAST(nodep, NodeUOrStructDType)) {
+            for (AstMemberDType* itemp = dtp->membersp(); itemp;
+                 itemp = VN_AS(itemp->nextp(), MemberDType)) {
+                AstNodeDType* const badDtp = dtypeNot4StateIntegralRecurse(itemp->dtypep());
+                if (badDtp) return badDtp;
+            }
+            return nullptr;
+        }
+        return nodep;
+    }
 
     //----------------------------------------------------------------------
     // METHODS - special type detection

src/Verilator.cpp

@@ -649,7 +649,6 @@ static void process() {
 
     // Final statistics
     if (v3Global.opt.stats()) V3Stats::statsStage("emit");
-    reportStatsIfEnabled();
 }
 
 static void verilate(const string& argString) {
@@ -769,6 +768,7 @@ static void verilate(const string& argString) {
 
     V3Os::filesystemFlushBuildDir(v3Global.opt.makeDir());
     if (v3Global.opt.hierTop()) V3Os::filesystemFlushBuildDir(v3Global.opt.hierTopDataDir());
+    if (v3Global.opt.stats()) V3Stats::statsStage("wrote");
 
     // Final writing shouldn't throw warnings, but...
     V3Error::abortIfWarnings();
@@ -867,6 +867,7 @@ int main(int argc, char** argv) {
         execBuildJob();
     }
 
+    reportStatsIfEnabled();
     V3DiagSarif::output(true);
 
     // Explicitly release resources

src/verilog.l

@@ -270,6 +270,7 @@ vnum    {vnum1}|{vnum2}|{vnum3}|{vnum4}|{vnum5}
   "$rewind"             { FL; return yD_REWIND; }
   "$rtoi"               { FL; return yD_RTOI; }
   "$sampled"            { FL; return yD_SAMPLED; }
+  "$sdf_annotate"       { FL; return yD_SDF_ANNOTATE; }
   "$setup"              { FL; return yaTIMINGSPEC; }
   "$setuphold"          { FL; return yD_SETUPHOLD; }
   "$sformat"            { FL; return yD_SFORMAT; }

src/verilog.y

@@ -98,6 +98,7 @@ public:
     bool m_tracingParse = true;  // Tracing disable for parser
     bool m_inImplements = false;  // Is inside class implements list
     bool m_insideProperty = false;  // Is inside property declaration
+    bool m_specifyignWarned = false;  // Issued a SPECIFYIGN warning
     bool m_typedPropertyPort = false;  // Typed property port occurred on port lists
     bool m_modportImpExpActive
         = false;  // Standalone ID is a tf_identifier instead of port_identifier
@@ -926,6 +927,7 @@ BISONPRE_VERSION(3.7,%define api.header.include {"V3ParseBison.h"})
 %token<fl>              yD_ROSE_GCLK    "$rose_gclk"
 %token<fl>              yD_RTOI         "$rtoi"
 %token<fl>              yD_SAMPLED      "$sampled"
+%token<fl>              yD_SDF_ANNOTATE "$sdf_annotate"
 %token<fl>              yD_SETUPHOLD    "$setuphold"
 %token<fl>              yD_SFORMAT      "$sformat"
 %token<fl>              yD_SFORMATF     "$sformatf"
@@ -2226,10 +2228,11 @@ data_typeNoRef<nodeDTypep>:             // ==IEEE: data_type, excluding class_ty
                                    new AstDefImplicitDType{$1->fileline(),
                                                            "__typeimpsu" + cvtToStr(GRAMMARP->s_typeImpNum++),
                                                            VFlagChildDType{}, $1}, $2, true); }
-        |       enumDecl
-                        { $$ = new AstDefImplicitDType{$1->fileline(),
-                                                       "__typeimpenum" + cvtToStr(GRAMMARP->s_typeImpNum++),
-                                                       VFlagChildDType{}, $1}; }
+        |       enumDecl packed_dimensionListE
+                        { $$ = GRAMMARP->createArray(
+                                   new AstDefImplicitDType{$1->fileline(),
+                                                           "__typeimpenum" + cvtToStr(GRAMMARP->s_typeImpNum++),
+                                                           VFlagChildDType{}, $1}, $2, true); }
         |       ySTRING
                         { $$ = new AstBasicDType{$1, VBasicDTypeKwd::STRING}; }
         |       yCHANDLE
@@ -3754,7 +3757,9 @@ statement_item<nodep>:          // IEEE: statement_item
         //                      // IEEE: disable_statement
         |       yDISABLE yFORK ';'                      { $$ = new AstDisableFork{$1}; }
         |       yDISABLE idDottedSel ';'
-                        { $$ = new AstDisable{$1, $2}; }
+                        { $$ = new AstDisable{$1, $2};
+                          PARSEP->importIfInStd($1, "process");
+                        }
         //                      // IEEE: event_trigger
         |       yP_MINUSGT expr ';'
                         { $$ = new AstFireEvent{$1, $2, false}; }
@@ -4178,6 +4183,7 @@ loop_variables<nodep>:          // IEEE: loop_variables
                 parseRefBase                            { $$ = $1; }
         |       loop_variables ',' parseRefBase         { $$ = $1->addNext($3); }
         |       ',' parseRefBase                        { $$ = new AstEmpty{$1}; $$->addNext($2); }
+        |       ','                                     { $$ = new AstEmpty{$1}; }
         ;
 
 //************************************************
@@ -4280,6 +4286,7 @@ system_t_call<nodeStmtp>:       // IEEE: system_tf_call (as task)
         |       yD_DUMPON '(' expr ')'                  { $$ = new AstDumpCtl{$<fl>1, VDumpCtlType::ON}; DEL($3); }
         //
         |       yD_C '(' cStrList ')'                   { $$ = (v3Global.opt.ignc() ? nullptr : new AstUCStmt{$1, $3}); }
+        |       yD_SDF_ANNOTATE '(' exprEListE ')'      { $$ = nullptr; $1->v3warn(SPECIFYIGN, "Ignoring unsupported: $sdf_annotate"); }
         |       yD_STACKTRACE parenE                    { $$ = new AstStackTraceT{$1}; }
         |       yD_SYSTEM '(' expr ')'                  { $$ = new AstSystemT{$1, $3}; }
         //
@@ -5349,6 +5356,11 @@ exprList<nodeExprp>:
         |       exprList ',' expr                       { $$ = $1->addNext($3); }
         ;
 
+exprEListE<nodep>:  // expression list with empty commas allowed
+                exprE                                   { $$ = $1; }
+        |       exprEListE ',' exprE                    { $$ = addNextNull($1, $3); }
+        ;
+
 exprDispList<nodeExprp>:            // exprList for within $display
                 expr                                    { $$ = $1; }
         |       exprDispList ',' expr                   { $$ = $1->addNext($3); }
@@ -5821,8 +5833,12 @@ tablelVal<udpTableLineValp>:
 // Specify
 
 specify_block<nodep>:               // ==IEEE: specify_block
-                ySPECIFY specify_itemList yENDSPECIFY   { $$ = $2; }
-        |       ySPECIFY yENDSPECIFY                    { $$ = nullptr; }
+                specifyFront specify_itemList yENDSPECIFY   { $$ = $2; }
+        |       specifyFront yENDSPECIFY                { $$ = nullptr; }
+        ;
+
+specifyFront:  // IEEE: specify_block front
+                ySPECIFY                                { GRAMMARP->m_specifyignWarned = false; }
         ;
 
 specify_itemList<nodep>:            // IEEE: { specify_item }
@@ -5833,7 +5849,13 @@ specify_itemList<nodep>:            // IEEE: { specify_item }
 specify_item<nodep>:                // ==IEEE: specify_item
                 specparam_declaration                   { $$ = $1; }
         |       system_timing_check                     { $$ = $1; }
-        |       junkToSemiList ';'                      { $$ = nullptr; }
+        |       junkToSemiList ';'
+                        { $$ = nullptr;
+                          if (!GRAMMARP->m_specifyignWarned) {
+                              GRAMMARP->m_specifyignWarned = true;
+                              $1->v3warn(SPECIFYIGN, "Ignoring unsupported: specify block construct");
+                          }
+                        }
         ;
 
 specparam_declaration<nodep>:       // ==IEEE: specparam_declaration
@@ -5922,9 +5944,9 @@ idAnyE<strp>:
         |       idAny                                   { $$ = $1; }
         ;
 
-junkToSemiList:
-                junkToSemi                              { } /* ignored */
-        |       junkToSemiList junkToSemi               { } /* ignored */
+junkToSemiList<fl>:
+                junkToSemi                              { $$ = CRELINE(); }
+        |       junkToSemiList junkToSemi               { $$ = CRELINE(); }
         ;
 
 junkToSemi:
@@ -6116,6 +6138,8 @@ idArrayedForeach<nodeExprp>:    // IEEE: id + select (under foreach expression)
         |       idArrayed '[' expr yP_MINUSCOLON constExpr ']'  { $$ = new AstSelMinus{$2, $1, $3, $5}; }
         //                      // IEEE: loop_variables (under foreach expression)
         //                      // To avoid conflicts we allow expr as first element, must post-check
+        |       idArrayed '[' ']'
+                        { $$ = new AstSelLoopVars{$2, $1, new AstEmpty{$3}}; }
         |       idArrayed '[' expr ',' loop_variables ']'
                         { $$ = new AstSelLoopVars{$2, $1, addNextNull(static_cast<AstNode*>($3), $5)}; }
         |       idArrayed '[' ',' loop_variables ']'
@@ -6819,21 +6843,38 @@ covergroup_declaration<nodep>:  // ==IEEE: covergroup_declaration
         |       covergroup_declarationFront '(' tf_port_listE ')'
         /*cont*/    coverage_eventE ';' coverage_spec_or_optionListE
         /*cont*/    yENDGROUP endLabelE
-                        { $$ = $1;
+                        { AstFunc* const newp = new AstFunc{$<fl>1, "new", nullptr, nullptr};
+                          newp->classMethod(true);
+                          newp->isConstructor(true);
+                          newp->dtypep($1->dtypep());
+                          newp->addStmtsp($3);
+                          $1->addMembersp(newp);
+                          $$ = $1;
                           GRAMMARP->endLabel($<fl>9, $1, $9); }
-        //                      // IEEE 1800-2023 added:
-        |       covergroup_declarationFront yEXTENDS idAny/*covergroup_identifier*/
-        /*cont*/    ';' coverage_spec_or_optionListE
-        /*cont*/    yENDGROUP endLabelE
-                        { $$ = $1;
-                          GRAMMARP->endLabel($<fl>7, $1, $7); }
+        ;
+
+covergroup_extendsE<fl>:  // IEEE: Part of covergroup_declaration
+                /* empty */                             { $$ = nullptr; }
+        |       yEXTENDS                                { $$ = $1; }
         ;
 
 covergroup_declarationFront<classp>:  // IEEE: part of covergroup_declaration
-                yCOVERGROUP idAny
-                        { $$ = new AstClass{$<fl>2, *$2, PARSEP->libname()};
+                yCOVERGROUP covergroup_extendsE idAny
+                        {
+                          $$ = new AstClass{$<fl>3, *$3, PARSEP->libname()};
+
+                          AstFunc* const sample = new AstFunc{$<fl>1, "sample", nullptr, nullptr};
+                          sample->classMethod(true);
+                          sample->dtypep(sample->findVoidDType());
+                          $$->addMembersp(sample);
+
+                          AstFunc* const getCoverage = new AstFunc{$<fl>1, "get_coverage", nullptr, nullptr};
+                          getCoverage->classMethod(true);
+                          getCoverage->dtypep(getCoverage->findVoidDType());
+                          $$->addMembersp(getCoverage);
+
                           BBCOVERIGN($<fl>1, "Ignoring unsupported: covergroup"); }
-        ;
+                ;
 
 cgexpr<nodeExprp>:  // IEEE-2012: covergroup_expression, before that just expression
                 expr                                    { $$ = $1; }
@@ -7003,7 +7044,7 @@ cross_itemList<nodep>:  // IEEE: part of list_of_cross_items
         ;
 
 cross_item<nodep>:  // ==IEEE: cross_item
-                idAny/*cover_point_identifier or variable_identifier*/  { $$ = nullptr; /*UNSUP*/ }
+                idDotted/*cover_point_identifier or variable_identifier*/  { $1->deleteTree(); $$ = nullptr; /*UNSUP*/ }
         ;
 
 cross_body<nodep>:  // ==IEEE: cross_body
@@ -7549,7 +7590,12 @@ class_item<nodep>:                      // ==IEEE: class_item
         |       class_declaration                       { $$ = $1; }
         |       timeunits_declaration                   { $$ = $1; }
         |       covergroup_declaration
-                        { $$ = nullptr; BBCOVERIGN($1, "Ignoring unsupported: covergroup within class"); }
+                        {
+                          const string cgName = $1->name();
+                          $1->name("__vlAnonCG_" + cgName);
+                          AstVar* const newp = new AstVar{$<fl>1, VVarType::VAR, cgName, VFlagChildDType{}, new AstRefDType($<fl>1, $1->name())};
+                          $$ = addNextNull($1, newp);
+                        }
         //                      // local_parameter_declaration under parameter_declaration
         |       parameter_declaration ';'               { $$ = $1; }
         |       ';'                                     { $$ = nullptr; }

test_regress/t/t_case_huge_sub.v

@@ -5,290 +5,284 @@
 // SPDX-License-Identifier: CC0-1.0
 
 module t_case_huge_sub (/*AUTOARG*/
-   // Outputs
-   outa, outb, outc,
-   // Inputs
-   index
-   );
+  // Outputs
+  outa, outb, outc,
+  // Inputs
+  index
+  );
 
-   input [7:0] index;
-   output [9:0] outa;
-   output [1:0] outb;
-   output       outc;
+  input [7:0] index;
+  output logic [9:0] outa;
+  output logic [1:0] outb;
+  output logic outc;
 
-   // =============================
-   /*AUTOREG*/
-   // Beginning of automatic regs (for this module's undeclared outputs)
-   reg [9:0]            outa;
-   reg [1:0]            outb;
-   reg                  outc;
-   // End of automatics
+  // =============================
+  // Created from Python3:
+  // for i in range(1024):
+  //    print("      10'h%03x: begin outa = 10'h%03x; outb = 2'b%d%d; outc = 1'b%d; end"
+  //        % (i, random.randint(0,1024), random.randint(0,1),
+  //          random.randint(0,1), random.randint(0,1)))
 
-   // =============================
-   // Created from Python3:
-   // for i in range(1024):
-   //     print("        10'h%03x: begin outa = 10'h%03x; outb = 2'b%d%d; outc = 1'b%d; end"
-   //           % (i, random.randint(0,1024), random.randint(0,1),
-   //              random.randint(0,1), random.randint(0,1)))
-
-   always @(/*AS*/index) begin
-      case (index)
-        8'h00: begin outa = 10'h152; outb = 2'b00; outc = 1'b1; end
-        8'h01: begin outa = 10'h318; outb = 2'b11; outc = 1'b1; end
-        8'h02: begin outa = 10'h29f; outb = 2'b11; outc = 1'b0; end
-        8'h03: begin outa = 10'h392; outb = 2'b01; outc = 1'b1; end
-        8'h04: begin outa = 10'h1ef; outb = 2'b00; outc = 1'b0; end
-        8'h05: begin outa = 10'h06c; outb = 2'b10; outc = 1'b1; end
-        8'h06: begin outa = 10'h29f; outb = 2'b11; outc = 1'b0; end
-        8'h07: begin outa = 10'h29a; outb = 2'b10; outc = 1'b0; end
-        8'h08: begin outa = 10'h3ce; outb = 2'b01; outc = 1'b0; end
-        8'h09: begin outa = 10'h37c; outb = 2'b01; outc = 1'b0; end
-        8'h0a: begin outa = 10'h058; outb = 2'b10; outc = 1'b0; end
-        8'h0b: begin outa = 10'h3b2; outb = 2'b01; outc = 1'b1; end
-        8'h0c: begin outa = 10'h36f; outb = 2'b11; outc = 1'b0; end
-        8'h0d: begin outa = 10'h2c5; outb = 2'b11; outc = 1'b0; end
-        8'h0e: begin outa = 10'h23a; outb = 2'b00; outc = 1'b0; end
-        8'h0f: begin outa = 10'h222; outb = 2'b01; outc = 1'b1; end
-        8'h10: begin outa = 10'h328; outb = 2'b00; outc = 1'b1; end
-        8'h11: begin outa = 10'h3c3; outb = 2'b00; outc = 1'b1; end
-        8'h12: begin outa = 10'h12c; outb = 2'b01; outc = 1'b0; end
-        8'h13: begin outa = 10'h1d0; outb = 2'b00; outc = 1'b1; end
-        8'h14: begin outa = 10'h3ff; outb = 2'b01; outc = 1'b1; end
-        8'h15: begin outa = 10'h115; outb = 2'b11; outc = 1'b1; end
-        8'h16: begin outa = 10'h3ba; outb = 2'b10; outc = 1'b0; end
-        8'h17: begin outa = 10'h3ba; outb = 2'b00; outc = 1'b0; end
-        8'h18: begin outa = 10'h10d; outb = 2'b00; outc = 1'b1; end
-        8'h19: begin outa = 10'h13b; outb = 2'b01; outc = 1'b1; end
-        8'h1a: begin outa = 10'h0a0; outb = 2'b10; outc = 1'b1; end
-        8'h1b: begin outa = 10'h264; outb = 2'b11; outc = 1'b0; end
-        8'h1c: begin outa = 10'h3a2; outb = 2'b10; outc = 1'b0; end
-        8'h1d: begin outa = 10'h07c; outb = 2'b00; outc = 1'b1; end
-        8'h1e: begin outa = 10'h291; outb = 2'b00; outc = 1'b0; end
-        8'h1f: begin outa = 10'h1d1; outb = 2'b10; outc = 1'b0; end
-        8'h20: begin outa = 10'h354; outb = 2'b11; outc = 1'b1; end
-        8'h21: begin outa = 10'h0c0; outb = 2'b00; outc = 1'b1; end
-        8'h22: begin outa = 10'h191; outb = 2'b00; outc = 1'b0; end
-        8'h23: begin outa = 10'h379; outb = 2'b01; outc = 1'b0; end
-        8'h24: begin outa = 10'h073; outb = 2'b00; outc = 1'b0; end
-        8'h25: begin outa = 10'h2fd; outb = 2'b11; outc = 1'b1; end
-        8'h26: begin outa = 10'h2e0; outb = 2'b11; outc = 1'b1; end
-        8'h27: begin outa = 10'h337; outb = 2'b01; outc = 1'b1; end
-        8'h28: begin outa = 10'h2c7; outb = 2'b11; outc = 1'b1; end
-        8'h29: begin outa = 10'h19e; outb = 2'b11; outc = 1'b0; end
-        8'h2a: begin outa = 10'h107; outb = 2'b10; outc = 1'b0; end
-        8'h2b: begin outa = 10'h06a; outb = 2'b01; outc = 1'b1; end
-        8'h2c: begin outa = 10'h1c7; outb = 2'b01; outc = 1'b1; end
-        8'h2d: begin outa = 10'h107; outb = 2'b10; outc = 1'b0; end
-        8'h2e: begin outa = 10'h0cf; outb = 2'b01; outc = 1'b1; end
-        8'h2f: begin outa = 10'h009; outb = 2'b11; outc = 1'b1; end
-        8'h30: begin outa = 10'h09d; outb = 2'b00; outc = 1'b1; end
-        8'h31: begin outa = 10'h28e; outb = 2'b00; outc = 1'b0; end
-        8'h32: begin outa = 10'h010; outb = 2'b01; outc = 1'b0; end
-        8'h33: begin outa = 10'h1e0; outb = 2'b10; outc = 1'b0; end
-        8'h34: begin outa = 10'h079; outb = 2'b01; outc = 1'b1; end
-        8'h35: begin outa = 10'h13e; outb = 2'b10; outc = 1'b1; end
-        8'h36: begin outa = 10'h282; outb = 2'b11; outc = 1'b0; end
-        8'h37: begin outa = 10'h21c; outb = 2'b11; outc = 1'b1; end
-        8'h38: begin outa = 10'h148; outb = 2'b00; outc = 1'b1; end
-        8'h39: begin outa = 10'h3c0; outb = 2'b10; outc = 1'b0; end
-        8'h3a: begin outa = 10'h176; outb = 2'b01; outc = 1'b1; end
-        8'h3b: begin outa = 10'h3fc; outb = 2'b10; outc = 1'b1; end
-        8'h3c: begin outa = 10'h295; outb = 2'b11; outc = 1'b1; end
-        8'h3d: begin outa = 10'h113; outb = 2'b10; outc = 1'b1; end
-        8'h3e: begin outa = 10'h354; outb = 2'b01; outc = 1'b1; end
-        8'h3f: begin outa = 10'h0db; outb = 2'b11; outc = 1'b0; end
-        8'h40: begin outa = 10'h238; outb = 2'b01; outc = 1'b0; end
-        8'h41: begin outa = 10'h12b; outb = 2'b01; outc = 1'b1; end
-        8'h42: begin outa = 10'h1dc; outb = 2'b10; outc = 1'b0; end
-        8'h43: begin outa = 10'h137; outb = 2'b01; outc = 1'b1; end
-        8'h44: begin outa = 10'h1e2; outb = 2'b01; outc = 1'b1; end
-        8'h45: begin outa = 10'h3d5; outb = 2'b11; outc = 1'b1; end
-        8'h46: begin outa = 10'h30c; outb = 2'b11; outc = 1'b0; end
-        8'h47: begin outa = 10'h298; outb = 2'b11; outc = 1'b0; end
-        8'h48: begin outa = 10'h080; outb = 2'b00; outc = 1'b1; end
-        8'h49: begin outa = 10'h35a; outb = 2'b11; outc = 1'b1; end
-        8'h4a: begin outa = 10'h01b; outb = 2'b00; outc = 1'b0; end
-        8'h4b: begin outa = 10'h0a3; outb = 2'b11; outc = 1'b0; end
-        8'h4c: begin outa = 10'h0b3; outb = 2'b11; outc = 1'b1; end
-        8'h4d: begin outa = 10'h17a; outb = 2'b00; outc = 1'b0; end
-        8'h4e: begin outa = 10'h3ae; outb = 2'b11; outc = 1'b0; end
-        8'h4f: begin outa = 10'h078; outb = 2'b11; outc = 1'b0; end
-        8'h50: begin outa = 10'h322; outb = 2'b00; outc = 1'b1; end
-        8'h51: begin outa = 10'h213; outb = 2'b11; outc = 1'b0; end
-        8'h52: begin outa = 10'h11a; outb = 2'b11; outc = 1'b0; end
-        8'h53: begin outa = 10'h1a7; outb = 2'b00; outc = 1'b0; end
-        8'h54: begin outa = 10'h35a; outb = 2'b00; outc = 1'b1; end
-        8'h55: begin outa = 10'h233; outb = 2'b00; outc = 1'b0; end
-        8'h56: begin outa = 10'h01d; outb = 2'b01; outc = 1'b1; end
-        8'h57: begin outa = 10'h2d5; outb = 2'b00; outc = 1'b0; end
-        8'h58: begin outa = 10'h1a0; outb = 2'b00; outc = 1'b1; end
-        8'h59: begin outa = 10'h3d0; outb = 2'b00; outc = 1'b1; end
-        8'h5a: begin outa = 10'h181; outb = 2'b01; outc = 1'b1; end
-        8'h5b: begin outa = 10'h219; outb = 2'b01; outc = 1'b1; end
-        8'h5c: begin outa = 10'h26a; outb = 2'b01; outc = 1'b1; end
-        8'h5d: begin outa = 10'h050; outb = 2'b10; outc = 1'b0; end
-        8'h5e: begin outa = 10'h189; outb = 2'b10; outc = 1'b0; end
-        8'h5f: begin outa = 10'h1eb; outb = 2'b01; outc = 1'b1; end
-        8'h60: begin outa = 10'h224; outb = 2'b00; outc = 1'b1; end
-        8'h61: begin outa = 10'h2fe; outb = 2'b00; outc = 1'b0; end
-        8'h62: begin outa = 10'h0ae; outb = 2'b00; outc = 1'b1; end
-        8'h63: begin outa = 10'h1cd; outb = 2'b00; outc = 1'b0; end
-        8'h64: begin outa = 10'h273; outb = 2'b10; outc = 1'b1; end
-        8'h65: begin outa = 10'h268; outb = 2'b10; outc = 1'b0; end
-        8'h66: begin outa = 10'h111; outb = 2'b01; outc = 1'b0; end
-        8'h67: begin outa = 10'h1f9; outb = 2'b00; outc = 1'b0; end
-        8'h68: begin outa = 10'h232; outb = 2'b00; outc = 1'b1; end
-        8'h69: begin outa = 10'h255; outb = 2'b11; outc = 1'b0; end
-        8'h6a: begin outa = 10'h34c; outb = 2'b01; outc = 1'b1; end
-        8'h6b: begin outa = 10'h049; outb = 2'b01; outc = 1'b1; end
-        8'h6c: begin outa = 10'h197; outb = 2'b11; outc = 1'b0; end
-        8'h6d: begin outa = 10'h0fe; outb = 2'b11; outc = 1'b0; end
-        8'h6e: begin outa = 10'h253; outb = 2'b01; outc = 1'b1; end
-        8'h6f: begin outa = 10'h2de; outb = 2'b11; outc = 1'b0; end
-        8'h70: begin outa = 10'h13b; outb = 2'b10; outc = 1'b1; end
-        8'h71: begin outa = 10'h040; outb = 2'b10; outc = 1'b0; end
-        8'h72: begin outa = 10'h0b4; outb = 2'b00; outc = 1'b1; end
-        8'h73: begin outa = 10'h233; outb = 2'b11; outc = 1'b1; end
-        8'h74: begin outa = 10'h198; outb = 2'b00; outc = 1'b1; end
-        8'h75: begin outa = 10'h018; outb = 2'b00; outc = 1'b1; end
-        8'h76: begin outa = 10'h2f7; outb = 2'b00; outc = 1'b1; end
-        8'h77: begin outa = 10'h134; outb = 2'b11; outc = 1'b0; end
-        8'h78: begin outa = 10'h1ca; outb = 2'b10; outc = 1'b0; end
-        8'h79: begin outa = 10'h286; outb = 2'b10; outc = 1'b1; end
-        8'h7a: begin outa = 10'h0e6; outb = 2'b11; outc = 1'b1; end
-        8'h7b: begin outa = 10'h064; outb = 2'b10; outc = 1'b1; end
-        8'h7c: begin outa = 10'h257; outb = 2'b00; outc = 1'b1; end
-        8'h7d: begin outa = 10'h31a; outb = 2'b10; outc = 1'b1; end
-        8'h7e: begin outa = 10'h247; outb = 2'b01; outc = 1'b0; end
-        8'h7f: begin outa = 10'h299; outb = 2'b00; outc = 1'b0; end
-        8'h80: begin outa = 10'h02c; outb = 2'b00; outc = 1'b0; end
-        8'h81: begin outa = 10'h2bb; outb = 2'b11; outc = 1'b0; end
-        8'h82: begin outa = 10'h180; outb = 2'b10; outc = 1'b0; end
-        8'h83: begin outa = 10'h245; outb = 2'b01; outc = 1'b1; end
-        8'h84: begin outa = 10'h0da; outb = 2'b10; outc = 1'b0; end
-        8'h85: begin outa = 10'h367; outb = 2'b10; outc = 1'b0; end
-        8'h86: begin outa = 10'h304; outb = 2'b01; outc = 1'b0; end
-        8'h87: begin outa = 10'h38b; outb = 2'b11; outc = 1'b0; end
-        8'h88: begin outa = 10'h09f; outb = 2'b01; outc = 1'b0; end
-        8'h89: begin outa = 10'h1f0; outb = 2'b10; outc = 1'b1; end
-        8'h8a: begin outa = 10'h281; outb = 2'b10; outc = 1'b1; end
-        8'h8b: begin outa = 10'h019; outb = 2'b00; outc = 1'b0; end
-        8'h8c: begin outa = 10'h1f2; outb = 2'b10; outc = 1'b0; end
-        8'h8d: begin outa = 10'h0b1; outb = 2'b01; outc = 1'b1; end
-        8'h8e: begin outa = 10'h058; outb = 2'b01; outc = 1'b1; end
-        8'h8f: begin outa = 10'h39b; outb = 2'b00; outc = 1'b1; end
-        8'h90: begin outa = 10'h2ec; outb = 2'b10; outc = 1'b1; end
-        8'h91: begin outa = 10'h250; outb = 2'b00; outc = 1'b1; end
-        8'h92: begin outa = 10'h3f4; outb = 2'b10; outc = 1'b1; end
-        8'h93: begin outa = 10'h057; outb = 2'b10; outc = 1'b1; end
-        8'h94: begin outa = 10'h18f; outb = 2'b01; outc = 1'b1; end
-        8'h95: begin outa = 10'h105; outb = 2'b01; outc = 1'b1; end
-        8'h96: begin outa = 10'h1ae; outb = 2'b00; outc = 1'b1; end
-        8'h97: begin outa = 10'h04e; outb = 2'b10; outc = 1'b0; end
-        8'h98: begin outa = 10'h240; outb = 2'b11; outc = 1'b0; end
-        8'h99: begin outa = 10'h3e4; outb = 2'b01; outc = 1'b0; end
-        8'h9a: begin outa = 10'h3c6; outb = 2'b01; outc = 1'b0; end
-        8'h9b: begin outa = 10'h109; outb = 2'b00; outc = 1'b1; end
-        8'h9c: begin outa = 10'h073; outb = 2'b10; outc = 1'b1; end
-        8'h9d: begin outa = 10'h19f; outb = 2'b01; outc = 1'b0; end
-        8'h9e: begin outa = 10'h3b8; outb = 2'b01; outc = 1'b0; end
-        8'h9f: begin outa = 10'h00e; outb = 2'b00; outc = 1'b1; end
-        8'ha0: begin outa = 10'h1b3; outb = 2'b11; outc = 1'b1; end
-        8'ha1: begin outa = 10'h2bd; outb = 2'b11; outc = 1'b0; end
-        8'ha2: begin outa = 10'h324; outb = 2'b00; outc = 1'b1; end
-        8'ha3: begin outa = 10'h343; outb = 2'b10; outc = 1'b0; end
-        8'ha4: begin outa = 10'h1c9; outb = 2'b01; outc = 1'b0; end
-        8'ha5: begin outa = 10'h185; outb = 2'b00; outc = 1'b1; end
-        8'ha6: begin outa = 10'h37a; outb = 2'b00; outc = 1'b1; end
-        8'ha7: begin outa = 10'h0e0; outb = 2'b01; outc = 1'b1; end
-        8'ha8: begin outa = 10'h0a3; outb = 2'b10; outc = 1'b0; end
-        8'ha9: begin outa = 10'h019; outb = 2'b11; outc = 1'b0; end
-        8'haa: begin outa = 10'h099; outb = 2'b00; outc = 1'b1; end
-        8'hab: begin outa = 10'h376; outb = 2'b01; outc = 1'b1; end
-        8'hac: begin outa = 10'h077; outb = 2'b00; outc = 1'b1; end
-        8'had: begin outa = 10'h2b1; outb = 2'b11; outc = 1'b1; end
-        8'hae: begin outa = 10'h27f; outb = 2'b00; outc = 1'b0; end
-        8'haf: begin outa = 10'h265; outb = 2'b11; outc = 1'b0; end
-        8'hb0: begin outa = 10'h156; outb = 2'b10; outc = 1'b1; end
-        8'hb1: begin outa = 10'h1ce; outb = 2'b00; outc = 1'b0; end
-        8'hb2: begin outa = 10'h008; outb = 2'b01; outc = 1'b0; end
-        8'hb3: begin outa = 10'h12e; outb = 2'b11; outc = 1'b1; end
-        8'hb4: begin outa = 10'h199; outb = 2'b11; outc = 1'b0; end
-        8'hb5: begin outa = 10'h330; outb = 2'b10; outc = 1'b0; end
-        8'hb6: begin outa = 10'h1ab; outb = 2'b01; outc = 1'b1; end
-        8'hb7: begin outa = 10'h3bd; outb = 2'b00; outc = 1'b0; end
-        8'hb8: begin outa = 10'h0ca; outb = 2'b10; outc = 1'b0; end
-        8'hb9: begin outa = 10'h367; outb = 2'b00; outc = 1'b0; end
-        8'hba: begin outa = 10'h334; outb = 2'b00; outc = 1'b0; end
-        8'hbb: begin outa = 10'h040; outb = 2'b00; outc = 1'b1; end
-        8'hbc: begin outa = 10'h1a7; outb = 2'b10; outc = 1'b1; end
-        8'hbd: begin outa = 10'h036; outb = 2'b11; outc = 1'b1; end
-        8'hbe: begin outa = 10'h223; outb = 2'b11; outc = 1'b1; end
-        8'hbf: begin outa = 10'h075; outb = 2'b01; outc = 1'b0; end
-        8'hc0: begin outa = 10'h3c4; outb = 2'b00; outc = 1'b1; end
-        8'hc1: begin outa = 10'h2cc; outb = 2'b01; outc = 1'b0; end
-        8'hc2: begin outa = 10'h123; outb = 2'b01; outc = 1'b0; end
-        8'hc3: begin outa = 10'h3fd; outb = 2'b01; outc = 1'b1; end
-        8'hc4: begin outa = 10'h11e; outb = 2'b00; outc = 1'b0; end
-        8'hc5: begin outa = 10'h27c; outb = 2'b11; outc = 1'b1; end
-        8'hc6: begin outa = 10'h1e2; outb = 2'b11; outc = 1'b0; end
-        8'hc7: begin outa = 10'h377; outb = 2'b11; outc = 1'b0; end
-        8'hc8: begin outa = 10'h33a; outb = 2'b11; outc = 1'b0; end
-        8'hc9: begin outa = 10'h32d; outb = 2'b11; outc = 1'b1; end
-        8'hca: begin outa = 10'h014; outb = 2'b11; outc = 1'b0; end
-        8'hcb: begin outa = 10'h332; outb = 2'b10; outc = 1'b0; end
-        8'hcc: begin outa = 10'h359; outb = 2'b00; outc = 1'b0; end
-        8'hcd: begin outa = 10'h0a4; outb = 2'b10; outc = 1'b1; end
-        8'hce: begin outa = 10'h348; outb = 2'b00; outc = 1'b1; end
-        8'hcf: begin outa = 10'h04b; outb = 2'b11; outc = 1'b1; end
-        8'hd0: begin outa = 10'h147; outb = 2'b10; outc = 1'b1; end
-        8'hd1: begin outa = 10'h026; outb = 2'b00; outc = 1'b1; end
-        8'hd2: begin outa = 10'h103; outb = 2'b00; outc = 1'b0; end
-        8'hd3: begin outa = 10'h106; outb = 2'b00; outc = 1'b1; end
-        8'hd4: begin outa = 10'h35a; outb = 2'b00; outc = 1'b0; end
-        8'hd5: begin outa = 10'h254; outb = 2'b01; outc = 1'b0; end
-        8'hd6: begin outa = 10'h0cd; outb = 2'b01; outc = 1'b0; end
-        8'hd7: begin outa = 10'h17c; outb = 2'b11; outc = 1'b1; end
-        8'hd8: begin outa = 10'h37e; outb = 2'b10; outc = 1'b1; end
-        8'hd9: begin outa = 10'h0a9; outb = 2'b11; outc = 1'b1; end
-        8'hda: begin outa = 10'h0fe; outb = 2'b01; outc = 1'b0; end
-        8'hdb: begin outa = 10'h3c0; outb = 2'b11; outc = 1'b1; end
-        8'hdc: begin outa = 10'h1d9; outb = 2'b10; outc = 1'b1; end
-        8'hdd: begin outa = 10'h10e; outb = 2'b00; outc = 1'b1; end
-        8'hde: begin outa = 10'h394; outb = 2'b01; outc = 1'b0; end
-        8'hdf: begin outa = 10'h316; outb = 2'b01; outc = 1'b0; end
-        8'he0: begin outa = 10'h05b; outb = 2'b11; outc = 1'b0; end
-        8'he1: begin outa = 10'h126; outb = 2'b01; outc = 1'b1; end
-        8'he2: begin outa = 10'h369; outb = 2'b11; outc = 1'b0; end
-        8'he3: begin outa = 10'h291; outb = 2'b10; outc = 1'b1; end
-        8'he4: begin outa = 10'h2ca; outb = 2'b00; outc = 1'b1; end
-        8'he5: begin outa = 10'h25b; outb = 2'b01; outc = 1'b1; end
-        8'he6: begin outa = 10'h106; outb = 2'b00; outc = 1'b0; end
-        8'he7: begin outa = 10'h172; outb = 2'b11; outc = 1'b1; end
-        8'he8: begin outa = 10'h2f7; outb = 2'b00; outc = 1'b1; end
-        8'he9: begin outa = 10'h2d3; outb = 2'b11; outc = 1'b1; end
-        8'hea: begin outa = 10'h182; outb = 2'b00; outc = 1'b0; end
-        8'heb: begin outa = 10'h327; outb = 2'b00; outc = 1'b1; end
-        8'hec: begin outa = 10'h1d0; outb = 2'b10; outc = 1'b0; end
-        8'hed: begin outa = 10'h204; outb = 2'b00; outc = 1'b1; end
-        8'hee: begin outa = 10'h11f; outb = 2'b00; outc = 1'b1; end
-        8'hef: begin outa = 10'h365; outb = 2'b11; outc = 1'b1; end
-        8'hf0: begin outa = 10'h2c2; outb = 2'b01; outc = 1'b1; end
-        8'hf1: begin outa = 10'h2b5; outb = 2'b10; outc = 1'b0; end
-        8'hf2: begin outa = 10'h1f8; outb = 2'b10; outc = 1'b1; end
-        8'hf3: begin outa = 10'h2a7; outb = 2'b01; outc = 1'b1; end
-        8'hf4: begin outa = 10'h1be; outb = 2'b10; outc = 1'b1; end
-        8'hf5: begin outa = 10'h25e; outb = 2'b10; outc = 1'b1; end
-        8'hf6: begin outa = 10'h032; outb = 2'b10; outc = 1'b0; end
-        8'hf7: begin outa = 10'h2ef; outb = 2'b00; outc = 1'b0; end
-        8'hf8: begin outa = 10'h02f; outb = 2'b00; outc = 1'b1; end
-        8'hf9: begin outa = 10'h201; outb = 2'b10; outc = 1'b0; end
-        8'hfa: begin outa = 10'h054; outb = 2'b01; outc = 1'b1; end
-        8'hfb: begin outa = 10'h013; outb = 2'b10; outc = 1'b0; end
-        8'hfc: begin outa = 10'h249; outb = 2'b01; outc = 1'b0; end
-        8'hfd: begin outa = 10'h09a; outb = 2'b10; outc = 1'b0; end
-        8'hfe: begin outa = 10'h012; outb = 2'b00; outc = 1'b0; end
-        8'hff: begin outa = 10'h114; outb = 2'b10; outc = 1'b1; end
-      endcase
-   end
+  always @* begin
+    // verilog_format: off
+    case (index)
+      8'h00: begin outa = 10'h152; outb = 2'b00; outc = 1'b1; end
+      8'h01: begin outa = 10'h318; outb = 2'b11; outc = 1'b1; end
+      8'h02: begin outa = 10'h29f; outb = 2'b11; outc = 1'b0; end
+      8'h03: begin outa = 10'h392; outb = 2'b01; outc = 1'b1; end
+      8'h04: begin outa = 10'h1ef; outb = 2'b00; outc = 1'b0; end
+      8'h05: begin outa = 10'h06c; outb = 2'b10; outc = 1'b1; end
+      8'h06: begin outa = 10'h29f; outb = 2'b11; outc = 1'b0; end
+      8'h07: begin outa = 10'h29a; outb = 2'b10; outc = 1'b0; end
+      8'h08: begin outa = 10'h3ce; outb = 2'b01; outc = 1'b0; end
+      8'h09: begin outa = 10'h37c; outb = 2'b01; outc = 1'b0; end
+      8'h0a: begin outa = 10'h058; outb = 2'b10; outc = 1'b0; end
+      8'h0b: begin outa = 10'h3b2; outb = 2'b01; outc = 1'b1; end
+      8'h0c: begin outa = 10'h36f; outb = 2'b11; outc = 1'b0; end
+      8'h0d: begin outa = 10'h2c5; outb = 2'b11; outc = 1'b0; end
+      8'h0e: begin outa = 10'h23a; outb = 2'b00; outc = 1'b0; end
+      8'h0f: begin outa = 10'h222; outb = 2'b01; outc = 1'b1; end
+      8'h10: begin outa = 10'h328; outb = 2'b00; outc = 1'b1; end
+      8'h11: begin outa = 10'h3c3; outb = 2'b00; outc = 1'b1; end
+      8'h12: begin outa = 10'h12c; outb = 2'b01; outc = 1'b0; end
+      8'h13: begin outa = 10'h1d0; outb = 2'b00; outc = 1'b1; end
+      8'h14: begin outa = 10'h3ff; outb = 2'b01; outc = 1'b1; end
+      8'h15: begin outa = 10'h115; outb = 2'b11; outc = 1'b1; end
+      8'h16: begin outa = 10'h3ba; outb = 2'b10; outc = 1'b0; end
+      8'h17: begin outa = 10'h3ba; outb = 2'b00; outc = 1'b0; end
+      8'h18: begin outa = 10'h10d; outb = 2'b00; outc = 1'b1; end
+      8'h19: begin outa = 10'h13b; outb = 2'b01; outc = 1'b1; end
+      8'h1a: begin outa = 10'h0a0; outb = 2'b10; outc = 1'b1; end
+      8'h1b: begin outa = 10'h264; outb = 2'b11; outc = 1'b0; end
+      8'h1c: begin outa = 10'h3a2; outb = 2'b10; outc = 1'b0; end
+      8'h1d: begin outa = 10'h07c; outb = 2'b00; outc = 1'b1; end
+      8'h1e: begin outa = 10'h291; outb = 2'b00; outc = 1'b0; end
+      8'h1f: begin outa = 10'h1d1; outb = 2'b10; outc = 1'b0; end
+      8'h20: begin outa = 10'h354; outb = 2'b11; outc = 1'b1; end
+      8'h21: begin outa = 10'h0c0; outb = 2'b00; outc = 1'b1; end
+      8'h22: begin outa = 10'h191; outb = 2'b00; outc = 1'b0; end
+      8'h23: begin outa = 10'h379; outb = 2'b01; outc = 1'b0; end
+      8'h24: begin outa = 10'h073; outb = 2'b00; outc = 1'b0; end
+      8'h25: begin outa = 10'h2fd; outb = 2'b11; outc = 1'b1; end
+      8'h26: begin outa = 10'h2e0; outb = 2'b11; outc = 1'b1; end
+      8'h27: begin outa = 10'h337; outb = 2'b01; outc = 1'b1; end
+      8'h28: begin outa = 10'h2c7; outb = 2'b11; outc = 1'b1; end
+      8'h29: begin outa = 10'h19e; outb = 2'b11; outc = 1'b0; end
+      8'h2a: begin outa = 10'h107; outb = 2'b10; outc = 1'b0; end
+      8'h2b: begin outa = 10'h06a; outb = 2'b01; outc = 1'b1; end
+      8'h2c: begin outa = 10'h1c7; outb = 2'b01; outc = 1'b1; end
+      8'h2d: begin outa = 10'h107; outb = 2'b10; outc = 1'b0; end
+      8'h2e: begin outa = 10'h0cf; outb = 2'b01; outc = 1'b1; end
+      8'h2f: begin outa = 10'h009; outb = 2'b11; outc = 1'b1; end
+      8'h30: begin outa = 10'h09d; outb = 2'b00; outc = 1'b1; end
+      8'h31: begin outa = 10'h28e; outb = 2'b00; outc = 1'b0; end
+      8'h32: begin outa = 10'h010; outb = 2'b01; outc = 1'b0; end
+      8'h33: begin outa = 10'h1e0; outb = 2'b10; outc = 1'b0; end
+      8'h34: begin outa = 10'h079; outb = 2'b01; outc = 1'b1; end
+      8'h35: begin outa = 10'h13e; outb = 2'b10; outc = 1'b1; end
+      8'h36: begin outa = 10'h282; outb = 2'b11; outc = 1'b0; end
+      8'h37: begin outa = 10'h21c; outb = 2'b11; outc = 1'b1; end
+      8'h38: begin outa = 10'h148; outb = 2'b00; outc = 1'b1; end
+      8'h39: begin outa = 10'h3c0; outb = 2'b10; outc = 1'b0; end
+      8'h3a: begin outa = 10'h176; outb = 2'b01; outc = 1'b1; end
+      8'h3b: begin outa = 10'h3fc; outb = 2'b10; outc = 1'b1; end
+      8'h3c: begin outa = 10'h295; outb = 2'b11; outc = 1'b1; end
+      8'h3d: begin outa = 10'h113; outb = 2'b10; outc = 1'b1; end
+      8'h3e: begin outa = 10'h354; outb = 2'b01; outc = 1'b1; end
+      8'h3f: begin outa = 10'h0db; outb = 2'b11; outc = 1'b0; end
+      8'h40: begin outa = 10'h238; outb = 2'b01; outc = 1'b0; end
+      8'h41: begin outa = 10'h12b; outb = 2'b01; outc = 1'b1; end
+      8'h42: begin outa = 10'h1dc; outb = 2'b10; outc = 1'b0; end
+      8'h43: begin outa = 10'h137; outb = 2'b01; outc = 1'b1; end
+      8'h44: begin outa = 10'h1e2; outb = 2'b01; outc = 1'b1; end
+      8'h45: begin outa = 10'h3d5; outb = 2'b11; outc = 1'b1; end
+      8'h46: begin outa = 10'h30c; outb = 2'b11; outc = 1'b0; end
+      8'h47: begin outa = 10'h298; outb = 2'b11; outc = 1'b0; end
+      8'h48: begin outa = 10'h080; outb = 2'b00; outc = 1'b1; end
+      8'h49: begin outa = 10'h35a; outb = 2'b11; outc = 1'b1; end
+      8'h4a: begin outa = 10'h01b; outb = 2'b00; outc = 1'b0; end
+      8'h4b: begin outa = 10'h0a3; outb = 2'b11; outc = 1'b0; end
+      8'h4c: begin outa = 10'h0b3; outb = 2'b11; outc = 1'b1; end
+      8'h4d: begin outa = 10'h17a; outb = 2'b00; outc = 1'b0; end
+      8'h4e: begin outa = 10'h3ae; outb = 2'b11; outc = 1'b0; end
+      8'h4f: begin outa = 10'h078; outb = 2'b11; outc = 1'b0; end
+      8'h50: begin outa = 10'h322; outb = 2'b00; outc = 1'b1; end
+      8'h51: begin outa = 10'h213; outb = 2'b11; outc = 1'b0; end
+      8'h52: begin outa = 10'h11a; outb = 2'b11; outc = 1'b0; end
+      8'h53: begin outa = 10'h1a7; outb = 2'b00; outc = 1'b0; end
+      8'h54: begin outa = 10'h35a; outb = 2'b00; outc = 1'b1; end
+      8'h55: begin outa = 10'h233; outb = 2'b00; outc = 1'b0; end
+      8'h56: begin outa = 10'h01d; outb = 2'b01; outc = 1'b1; end
+      8'h57: begin outa = 10'h2d5; outb = 2'b00; outc = 1'b0; end
+      8'h58: begin outa = 10'h1a0; outb = 2'b00; outc = 1'b1; end
+      8'h59: begin outa = 10'h3d0; outb = 2'b00; outc = 1'b1; end
+      8'h5a: begin outa = 10'h181; outb = 2'b01; outc = 1'b1; end
+      8'h5b: begin outa = 10'h219; outb = 2'b01; outc = 1'b1; end
+      8'h5c: begin outa = 10'h26a; outb = 2'b01; outc = 1'b1; end
+      8'h5d: begin outa = 10'h050; outb = 2'b10; outc = 1'b0; end
+      8'h5e: begin outa = 10'h189; outb = 2'b10; outc = 1'b0; end
+      8'h5f: begin outa = 10'h1eb; outb = 2'b01; outc = 1'b1; end
+      8'h60: begin outa = 10'h224; outb = 2'b00; outc = 1'b1; end
+      8'h61: begin outa = 10'h2fe; outb = 2'b00; outc = 1'b0; end
+      8'h62: begin outa = 10'h0ae; outb = 2'b00; outc = 1'b1; end
+      8'h63: begin outa = 10'h1cd; outb = 2'b00; outc = 1'b0; end
+      8'h64: begin outa = 10'h273; outb = 2'b10; outc = 1'b1; end
+      8'h65: begin outa = 10'h268; outb = 2'b10; outc = 1'b0; end
+      8'h66: begin outa = 10'h111; outb = 2'b01; outc = 1'b0; end
+      8'h67: begin outa = 10'h1f9; outb = 2'b00; outc = 1'b0; end
+      8'h68: begin outa = 10'h232; outb = 2'b00; outc = 1'b1; end
+      8'h69: begin outa = 10'h255; outb = 2'b11; outc = 1'b0; end
+      8'h6a: begin outa = 10'h34c; outb = 2'b01; outc = 1'b1; end
+      8'h6b: begin outa = 10'h049; outb = 2'b01; outc = 1'b1; end
+      8'h6c: begin outa = 10'h197; outb = 2'b11; outc = 1'b0; end
+      8'h6d: begin outa = 10'h0fe; outb = 2'b11; outc = 1'b0; end
+      8'h6e: begin outa = 10'h253; outb = 2'b01; outc = 1'b1; end
+      8'h6f: begin outa = 10'h2de; outb = 2'b11; outc = 1'b0; end
+      8'h70: begin outa = 10'h13b; outb = 2'b10; outc = 1'b1; end
+      8'h71: begin outa = 10'h040; outb = 2'b10; outc = 1'b0; end
+      8'h72: begin outa = 10'h0b4; outb = 2'b00; outc = 1'b1; end
+      8'h73: begin outa = 10'h233; outb = 2'b11; outc = 1'b1; end
+      8'h74: begin outa = 10'h198; outb = 2'b00; outc = 1'b1; end
+      8'h75: begin outa = 10'h018; outb = 2'b00; outc = 1'b1; end
+      8'h76: begin outa = 10'h2f7; outb = 2'b00; outc = 1'b1; end
+      8'h77: begin outa = 10'h134; outb = 2'b11; outc = 1'b0; end
+      8'h78: begin outa = 10'h1ca; outb = 2'b10; outc = 1'b0; end
+      8'h79: begin outa = 10'h286; outb = 2'b10; outc = 1'b1; end
+      8'h7a: begin outa = 10'h0e6; outb = 2'b11; outc = 1'b1; end
+      8'h7b: begin outa = 10'h064; outb = 2'b10; outc = 1'b1; end
+      8'h7c: begin outa = 10'h257; outb = 2'b00; outc = 1'b1; end
+      8'h7d: begin outa = 10'h31a; outb = 2'b10; outc = 1'b1; end
+      8'h7e: begin outa = 10'h247; outb = 2'b01; outc = 1'b0; end
+      8'h7f: begin outa = 10'h299; outb = 2'b00; outc = 1'b0; end
+      8'h80: begin outa = 10'h02c; outb = 2'b00; outc = 1'b0; end
+      8'h81: begin outa = 10'h2bb; outb = 2'b11; outc = 1'b0; end
+      8'h82: begin outa = 10'h180; outb = 2'b10; outc = 1'b0; end
+      8'h83: begin outa = 10'h245; outb = 2'b01; outc = 1'b1; end
+      8'h84: begin outa = 10'h0da; outb = 2'b10; outc = 1'b0; end
+      8'h85: begin outa = 10'h367; outb = 2'b10; outc = 1'b0; end
+      8'h86: begin outa = 10'h304; outb = 2'b01; outc = 1'b0; end
+      8'h87: begin outa = 10'h38b; outb = 2'b11; outc = 1'b0; end
+      8'h88: begin outa = 10'h09f; outb = 2'b01; outc = 1'b0; end
+      8'h89: begin outa = 10'h1f0; outb = 2'b10; outc = 1'b1; end
+      8'h8a: begin outa = 10'h281; outb = 2'b10; outc = 1'b1; end
+      8'h8b: begin outa = 10'h019; outb = 2'b00; outc = 1'b0; end
+      8'h8c: begin outa = 10'h1f2; outb = 2'b10; outc = 1'b0; end
+      8'h8d: begin outa = 10'h0b1; outb = 2'b01; outc = 1'b1; end
+      8'h8e: begin outa = 10'h058; outb = 2'b01; outc = 1'b1; end
+      8'h8f: begin outa = 10'h39b; outb = 2'b00; outc = 1'b1; end
+      8'h90: begin outa = 10'h2ec; outb = 2'b10; outc = 1'b1; end
+      8'h91: begin outa = 10'h250; outb = 2'b00; outc = 1'b1; end
+      8'h92: begin outa = 10'h3f4; outb = 2'b10; outc = 1'b1; end
+      8'h93: begin outa = 10'h057; outb = 2'b10; outc = 1'b1; end
+      8'h94: begin outa = 10'h18f; outb = 2'b01; outc = 1'b1; end
+      8'h95: begin outa = 10'h105; outb = 2'b01; outc = 1'b1; end
+      8'h96: begin outa = 10'h1ae; outb = 2'b00; outc = 1'b1; end
+      8'h97: begin outa = 10'h04e; outb = 2'b10; outc = 1'b0; end
+      8'h98: begin outa = 10'h240; outb = 2'b11; outc = 1'b0; end
+      8'h99: begin outa = 10'h3e4; outb = 2'b01; outc = 1'b0; end
+      8'h9a: begin outa = 10'h3c6; outb = 2'b01; outc = 1'b0; end
+      8'h9b: begin outa = 10'h109; outb = 2'b00; outc = 1'b1; end
+      8'h9c: begin outa = 10'h073; outb = 2'b10; outc = 1'b1; end
+      8'h9d: begin outa = 10'h19f; outb = 2'b01; outc = 1'b0; end
+      8'h9e: begin outa = 10'h3b8; outb = 2'b01; outc = 1'b0; end
+      8'h9f: begin outa = 10'h00e; outb = 2'b00; outc = 1'b1; end
+      8'ha0: begin outa = 10'h1b3; outb = 2'b11; outc = 1'b1; end
+      8'ha1: begin outa = 10'h2bd; outb = 2'b11; outc = 1'b0; end
+      8'ha2: begin outa = 10'h324; outb = 2'b00; outc = 1'b1; end
+      8'ha3: begin outa = 10'h343; outb = 2'b10; outc = 1'b0; end
+      8'ha4: begin outa = 10'h1c9; outb = 2'b01; outc = 1'b0; end
+      8'ha5: begin outa = 10'h185; outb = 2'b00; outc = 1'b1; end
+      8'ha6: begin outa = 10'h37a; outb = 2'b00; outc = 1'b1; end
+      8'ha7: begin outa = 10'h0e0; outb = 2'b01; outc = 1'b1; end
+      8'ha8: begin outa = 10'h0a3; outb = 2'b10; outc = 1'b0; end
+      8'ha9: begin outa = 10'h019; outb = 2'b11; outc = 1'b0; end
+      8'haa: begin outa = 10'h099; outb = 2'b00; outc = 1'b1; end
+      8'hab: begin outa = 10'h376; outb = 2'b01; outc = 1'b1; end
+      8'hac: begin outa = 10'h077; outb = 2'b00; outc = 1'b1; end
+      8'had: begin outa = 10'h2b1; outb = 2'b11; outc = 1'b1; end
+      8'hae: begin outa = 10'h27f; outb = 2'b00; outc = 1'b0; end
+      8'haf: begin outa = 10'h265; outb = 2'b11; outc = 1'b0; end
+      8'hb0: begin outa = 10'h156; outb = 2'b10; outc = 1'b1; end
+      8'hb1: begin outa = 10'h1ce; outb = 2'b00; outc = 1'b0; end
+      8'hb2: begin outa = 10'h008; outb = 2'b01; outc = 1'b0; end
+      8'hb3: begin outa = 10'h12e; outb = 2'b11; outc = 1'b1; end
+      8'hb4: begin outa = 10'h199; outb = 2'b11; outc = 1'b0; end
+      8'hb5: begin outa = 10'h330; outb = 2'b10; outc = 1'b0; end
+      8'hb6: begin outa = 10'h1ab; outb = 2'b01; outc = 1'b1; end
+      8'hb7: begin outa = 10'h3bd; outb = 2'b00; outc = 1'b0; end
+      8'hb8: begin outa = 10'h0ca; outb = 2'b10; outc = 1'b0; end
+      8'hb9: begin outa = 10'h367; outb = 2'b00; outc = 1'b0; end
+      8'hba: begin outa = 10'h334; outb = 2'b00; outc = 1'b0; end
+      8'hbb: begin outa = 10'h040; outb = 2'b00; outc = 1'b1; end
+      8'hbc: begin outa = 10'h1a7; outb = 2'b10; outc = 1'b1; end
+      8'hbd: begin outa = 10'h036; outb = 2'b11; outc = 1'b1; end
+      8'hbe: begin outa = 10'h223; outb = 2'b11; outc = 1'b1; end
+      8'hbf: begin outa = 10'h075; outb = 2'b01; outc = 1'b0; end
+      8'hc0: begin outa = 10'h3c4; outb = 2'b00; outc = 1'b1; end
+      8'hc1: begin outa = 10'h2cc; outb = 2'b01; outc = 1'b0; end
+      8'hc2: begin outa = 10'h123; outb = 2'b01; outc = 1'b0; end
+      8'hc3: begin outa = 10'h3fd; outb = 2'b01; outc = 1'b1; end
+      8'hc4: begin outa = 10'h11e; outb = 2'b00; outc = 1'b0; end
+      8'hc5: begin outa = 10'h27c; outb = 2'b11; outc = 1'b1; end
+      8'hc6: begin outa = 10'h1e2; outb = 2'b11; outc = 1'b0; end
+      8'hc7: begin outa = 10'h377; outb = 2'b11; outc = 1'b0; end
+      8'hc8: begin outa = 10'h33a; outb = 2'b11; outc = 1'b0; end
+      8'hc9: begin outa = 10'h32d; outb = 2'b11; outc = 1'b1; end
+      8'hca: begin outa = 10'h014; outb = 2'b11; outc = 1'b0; end
+      8'hcb: begin outa = 10'h332; outb = 2'b10; outc = 1'b0; end
+      8'hcc: begin outa = 10'h359; outb = 2'b00; outc = 1'b0; end
+      8'hcd: begin outa = 10'h0a4; outb = 2'b10; outc = 1'b1; end
+      8'hce: begin outa = 10'h348; outb = 2'b00; outc = 1'b1; end
+      8'hcf: begin outa = 10'h04b; outb = 2'b11; outc = 1'b1; end
+      8'hd0: begin outa = 10'h147; outb = 2'b10; outc = 1'b1; end
+      8'hd1: begin outa = 10'h026; outb = 2'b00; outc = 1'b1; end
+      8'hd2: begin outa = 10'h103; outb = 2'b00; outc = 1'b0; end
+      8'hd3: begin outa = 10'h106; outb = 2'b00; outc = 1'b1; end
+      8'hd4: begin outa = 10'h35a; outb = 2'b00; outc = 1'b0; end
+      8'hd5: begin outa = 10'h254; outb = 2'b01; outc = 1'b0; end
+      8'hd6: begin outa = 10'h0cd; outb = 2'b01; outc = 1'b0; end
+      8'hd7: begin outa = 10'h17c; outb = 2'b11; outc = 1'b1; end
+      8'hd8: begin outa = 10'h37e; outb = 2'b10; outc = 1'b1; end
+      8'hd9: begin outa = 10'h0a9; outb = 2'b11; outc = 1'b1; end
+      8'hda: begin outa = 10'h0fe; outb = 2'b01; outc = 1'b0; end
+      8'hdb: begin outa = 10'h3c0; outb = 2'b11; outc = 1'b1; end
+      8'hdc: begin outa = 10'h1d9; outb = 2'b10; outc = 1'b1; end
+      8'hdd: begin outa = 10'h10e; outb = 2'b00; outc = 1'b1; end
+      8'hde: begin outa = 10'h394; outb = 2'b01; outc = 1'b0; end
+      8'hdf: begin outa = 10'h316; outb = 2'b01; outc = 1'b0; end
+      8'he0: begin outa = 10'h05b; outb = 2'b11; outc = 1'b0; end
+      8'he1: begin outa = 10'h126; outb = 2'b01; outc = 1'b1; end
+      8'he2: begin outa = 10'h369; outb = 2'b11; outc = 1'b0; end
+      8'he3: begin outa = 10'h291; outb = 2'b10; outc = 1'b1; end
+      8'he4: begin outa = 10'h2ca; outb = 2'b00; outc = 1'b1; end
+      8'he5: begin outa = 10'h25b; outb = 2'b01; outc = 1'b1; end
+      8'he6: begin outa = 10'h106; outb = 2'b00; outc = 1'b0; end
+      8'he7: begin outa = 10'h172; outb = 2'b11; outc = 1'b1; end
+      8'he8: begin outa = 10'h2f7; outb = 2'b00; outc = 1'b1; end
+      8'he9: begin outa = 10'h2d3; outb = 2'b11; outc = 1'b1; end
+      8'hea: begin outa = 10'h182; outb = 2'b00; outc = 1'b0; end
+      8'heb: begin outa = 10'h327; outb = 2'b00; outc = 1'b1; end
+      8'hec: begin outa = 10'h1d0; outb = 2'b10; outc = 1'b0; end
+      8'hed: begin outa = 10'h204; outb = 2'b00; outc = 1'b1; end
+      8'hee: begin outa = 10'h11f; outb = 2'b00; outc = 1'b1; end
+      8'hef: begin outa = 10'h365; outb = 2'b11; outc = 1'b1; end
+      8'hf0: begin outa = 10'h2c2; outb = 2'b01; outc = 1'b1; end
+      8'hf1: begin outa = 10'h2b5; outb = 2'b10; outc = 1'b0; end
+      8'hf2: begin outa = 10'h1f8; outb = 2'b10; outc = 1'b1; end
+      8'hf3: begin outa = 10'h2a7; outb = 2'b01; outc = 1'b1; end
+      8'hf4: begin outa = 10'h1be; outb = 2'b10; outc = 1'b1; end
+      8'hf5: begin outa = 10'h25e; outb = 2'b10; outc = 1'b1; end
+      8'hf6: begin outa = 10'h032; outb = 2'b10; outc = 1'b0; end
+      8'hf7: begin outa = 10'h2ef; outb = 2'b00; outc = 1'b0; end
+      8'hf8: begin outa = 10'h02f; outb = 2'b00; outc = 1'b1; end
+      8'hf9: begin outa = 10'h201; outb = 2'b10; outc = 1'b0; end
+      8'hfa: begin outa = 10'h054; outb = 2'b01; outc = 1'b1; end
+      8'hfb: begin outa = 10'h013; outb = 2'b10; outc = 1'b0; end
+      8'hfc: begin outa = 10'h249; outb = 2'b01; outc = 1'b0; end
+      8'hfd: begin outa = 10'h09a; outb = 2'b10; outc = 1'b0; end
+      8'hfe: begin outa = 10'h012; outb = 2'b00; outc = 1'b0; end
+      8'hff: begin outa = 10'h114; outb = 2'b10; outc = 1'b1; end
+    endcase
+    // verilog_format: on
+  end
 endmodule

test_regress/t/t_case_huge_sub2.v

@@ -5,290 +5,286 @@
 // SPDX-License-Identifier: CC0-1.0
 
 module t_case_huge_sub2 (/*AUTOARG*/
-   // Outputs
-   outa,
-   // Inputs
-   index
-   );
+  // Outputs
+  outa,
+  // Inputs
+  index
+  );
 
-   input [9:0] index;
-   output [9:0] outa;
+  input [9:0] index;
+  output logic [9:0] outa;
 
-   // =============================
-   /*AUTOREG*/
-   // Beginning of automatic regs (for this module's undeclared outputs)
-   reg [9:0]            outa;
-   // End of automatics
+  // =============================
+  // Created from Python3:
+  // for i in range(1024):
+  //    print("      10'h%03x: begin outa = 10'h%03x; outb = 2'b%d%d; outc = 1'b%d; end"
+  //        % (i, random.randint(0,1024), random.randint(0,1),
+  //          random.randint(0,1), random.randint(0,1)))
 
-   // =============================
-   // Created from Python3:
-   // for i in range(1024):
-   //     print("        10'h%03x: begin outa = 10'h%03x; outb = 2'b%d%d; outc = 1'b%d; end"
-   //           % (i, random.randint(0,1024), random.randint(0,1),
-   //              random.randint(0,1), random.randint(0,1)))
-
-   always @(/*AS*/index) begin
-      case (index[7:0])
-`ifdef VERILATOR // Harder test
-        8'h00: begin outa = $c("0"); end // Makes whole table non-optimizable
+  always @(/*AS*/index) begin
+    case (index[7:0])
+`ifdef VERILATOR  // Harder test
+      8'h00: begin
+        outa = $c("0");
+      end  // Makes whole table non-optimizable
 `else
-        8'h00: begin outa = 10'h0; end
+      8'h00: outa = 10'h0;
 `endif
-        8'h01: begin outa = 10'h318; end
-        8'h02: begin outa = 10'h29f; end
-        8'h03: begin outa = 10'h392; end
-        8'h04: begin outa = 10'h1ef; end
-        8'h05: begin outa = 10'h06c; end
-        8'h06: begin outa = 10'h29f; end
-        8'h07: begin outa = 10'h29a; end
-        8'h08: begin outa = 10'h3ce; end
-        8'h09: begin outa = 10'h37c; end
-        8'h0a: begin outa = 10'h058; end
-        8'h0b: begin outa = 10'h3b2; end
-        8'h0c: begin outa = 10'h36f; end
-        8'h0d: begin outa = 10'h2c5; end
-        8'h0e: begin outa = 10'h23a; end
-        8'h0f: begin outa = 10'h222; end
-        8'h10: begin outa = 10'h328; end
-        8'h11: begin outa = 10'h3c3; end
-        8'h12: begin outa = 10'h12c; end
-        8'h13: begin outa = 10'h1d0; end
-        8'h14: begin outa = 10'h3ff; end
-        8'h15: begin outa = 10'h115; end
-        8'h16: begin outa = 10'h3ba; end
-        8'h17: begin outa = 10'h3ba; end
-        8'h18: begin outa = 10'h10d; end
-        8'h19: begin outa = 10'h13b; end
-        8'h1a: begin outa = 10'h0a0; end
-        8'h1b: begin outa = 10'h264; end
-        8'h1c: begin outa = 10'h3a2; end
-        8'h1d: begin outa = 10'h07c; end
-        8'h1e: begin outa = 10'h291; end
-        8'h1f: begin outa = 10'h1d1; end
-        8'h20: begin outa = 10'h354; end
-        8'h21: begin outa = 10'h0c0; end
-        8'h22: begin outa = 10'h191; end
-        8'h23: begin outa = 10'h379; end
-        8'h24: begin outa = 10'h073; end
-        8'h25: begin outa = 10'h2fd; end
-        8'h26: begin outa = 10'h2e0; end
-        8'h27: begin outa = 10'h337; end
-        8'h28: begin outa = 10'h2c7; end
-        8'h29: begin outa = 10'h19e; end
-        8'h2a: begin outa = 10'h107; end
-        8'h2b: begin outa = 10'h06a; end
-        8'h2c: begin outa = 10'h1c7; end
-        8'h2d: begin outa = 10'h107; end
-        8'h2e: begin outa = 10'h0cf; end
-        8'h2f: begin outa = 10'h009; end
-        8'h30: begin outa = 10'h09d; end
-        8'h31: begin outa = 10'h28e; end
-        8'h32: begin outa = 10'h010; end
-        8'h33: begin outa = 10'h1e0; end
-        8'h34: begin outa = 10'h079; end
-        8'h35: begin outa = 10'h13e; end
-        8'h36: begin outa = 10'h282; end
-        8'h37: begin outa = 10'h21c; end
-        8'h38: begin outa = 10'h148; end
-        8'h39: begin outa = 10'h3c0; end
-        8'h3a: begin outa = 10'h176; end
-        8'h3b: begin outa = 10'h3fc; end
-        8'h3c: begin outa = 10'h295; end
-        8'h3d: begin outa = 10'h113; end
-        8'h3e: begin outa = 10'h354; end
-        8'h3f: begin outa = 10'h0db; end
-        8'h40: begin outa = 10'h238; end
-        8'h41: begin outa = 10'h12b; end
-        8'h42: begin outa = 10'h1dc; end
-        8'h43: begin outa = 10'h137; end
-        8'h44: begin outa = 10'h1e2; end
-        8'h45: begin outa = 10'h3d5; end
-        8'h46: begin outa = 10'h30c; end
-        8'h47: begin outa = 10'h298; end
-        8'h48: begin outa = 10'h080; end
-        8'h49: begin outa = 10'h35a; end
-        8'h4a: begin outa = 10'h01b; end
-        8'h4b: begin outa = 10'h0a3; end
-        8'h4c: begin outa = 10'h0b3; end
-        8'h4d: begin outa = 10'h17a; end
-        8'h4e: begin outa = 10'h3ae; end
-        8'h4f: begin outa = 10'h078; end
-        8'h50: begin outa = 10'h322; end
-        8'h51: begin outa = 10'h213; end
-        8'h52: begin outa = 10'h11a; end
-        8'h53: begin outa = 10'h1a7; end
-        8'h54: begin outa = 10'h35a; end
-        8'h55: begin outa = 10'h233; end
-        8'h56: begin outa = 10'h01d; end
-        8'h57: begin outa = 10'h2d5; end
-        8'h58: begin outa = 10'h1a0; end
-        8'h59: begin outa = 10'h3d0; end
-        8'h5a: begin outa = 10'h181; end
-        8'h5b: begin outa = 10'h219; end
-        8'h5c: begin outa = 10'h26a; end
-        8'h5d: begin outa = 10'h050; end
-        8'h5e: begin outa = 10'h189; end
-        8'h5f: begin outa = 10'h1eb; end
-        8'h60: begin outa = 10'h224; end
-        8'h61: begin outa = 10'h2fe; end
-        8'h62: begin outa = 10'h0ae; end
-        8'h63: begin outa = 10'h1cd; end
-        8'h64: begin outa = 10'h273; end
-        8'h65: begin outa = 10'h268; end
-        8'h66: begin outa = 10'h111; end
-        8'h67: begin outa = 10'h1f9; end
-        8'h68: begin outa = 10'h232; end
-        8'h69: begin outa = 10'h255; end
-        8'h6a: begin outa = 10'h34c; end
-        8'h6b: begin outa = 10'h049; end
-        8'h6c: begin outa = 10'h197; end
-        8'h6d: begin outa = 10'h0fe; end
-        8'h6e: begin outa = 10'h253; end
-        8'h6f: begin outa = 10'h2de; end
-        8'h70: begin outa = 10'h13b; end
-        8'h71: begin outa = 10'h040; end
-        8'h72: begin outa = 10'h0b4; end
-        8'h73: begin outa = 10'h233; end
-        8'h74: begin outa = 10'h198; end
-        8'h75: begin outa = 10'h018; end
-        8'h76: begin outa = 10'h2f7; end
-        8'h77: begin outa = 10'h134; end
-        8'h78: begin outa = 10'h1ca; end
-        8'h79: begin outa = 10'h286; end
-        8'h7a: begin outa = 10'h0e6; end
-        8'h7b: begin outa = 10'h064; end
-        8'h7c: begin outa = 10'h257; end
-        8'h7d: begin outa = 10'h31a; end
-        8'h7e: begin outa = 10'h247; end
-        8'h7f: begin outa = 10'h299; end
-        8'h80: begin outa = 10'h02c; end
-        8'h81: begin outa = 10'h2bb; end
-        8'h82: begin outa = 10'h180; end
-        8'h83: begin outa = 10'h245; end
-        8'h84: begin outa = 10'h0da; end
-        8'h85: begin outa = 10'h367; end
-        8'h86: begin outa = 10'h304; end
-        8'h87: begin outa = 10'h38b; end
-        8'h88: begin outa = 10'h09f; end
-        8'h89: begin outa = 10'h1f0; end
-        8'h8a: begin outa = 10'h281; end
-        8'h8b: begin outa = 10'h019; end
-        8'h8c: begin outa = 10'h1f2; end
-        8'h8d: begin outa = 10'h0b1; end
-        8'h8e: begin outa = 10'h058; end
-        8'h8f: begin outa = 10'h39b; end
-        8'h90: begin outa = 10'h2ec; end
-        8'h91: begin outa = 10'h250; end
-        8'h92: begin outa = 10'h3f4; end
-        8'h93: begin outa = 10'h057; end
-        8'h94: begin outa = 10'h18f; end
-        8'h95: begin outa = 10'h105; end
-        8'h96: begin outa = 10'h1ae; end
-        8'h97: begin outa = 10'h04e; end
-        8'h98: begin outa = 10'h240; end
-        8'h99: begin outa = 10'h3e4; end
-        8'h9a: begin outa = 10'h3c6; end
-        8'h9b: begin outa = 10'h109; end
-        8'h9c: begin outa = 10'h073; end
-        8'h9d: begin outa = 10'h19f; end
-        8'h9e: begin outa = 10'h3b8; end
-        8'h9f: begin outa = 10'h00e; end
-        8'ha0: begin outa = 10'h1b3; end
-        8'ha1: begin outa = 10'h2bd; end
-        8'ha2: begin outa = 10'h324; end
-        8'ha3: begin outa = 10'h343; end
-        8'ha4: begin outa = 10'h1c9; end
-        8'ha5: begin outa = 10'h185; end
-        8'ha6: begin outa = 10'h37a; end
-        8'ha7: begin outa = 10'h0e0; end
-        8'ha8: begin outa = 10'h0a3; end
-        8'ha9: begin outa = 10'h019; end
-        8'haa: begin outa = 10'h099; end
-        8'hab: begin outa = 10'h376; end
-        8'hac: begin outa = 10'h077; end
-        8'had: begin outa = 10'h2b1; end
-        8'hae: begin outa = 10'h27f; end
-        8'haf: begin outa = 10'h265; end
-        8'hb0: begin outa = 10'h156; end
-        8'hb1: begin outa = 10'h1ce; end
-        8'hb2: begin outa = 10'h008; end
-        8'hb3: begin outa = 10'h12e; end
-        8'hb4: begin outa = 10'h199; end
-        8'hb5: begin outa = 10'h330; end
-        8'hb6: begin outa = 10'h1ab; end
-        8'hb7: begin outa = 10'h3bd; end
-        8'hb8: begin outa = 10'h0ca; end
-        8'hb9: begin outa = 10'h367; end
-        8'hba: begin outa = 10'h334; end
-        8'hbb: begin outa = 10'h040; end
-        8'hbc: begin outa = 10'h1a7; end
-        8'hbd: begin outa = 10'h036; end
-        8'hbe: begin outa = 10'h223; end
-        8'hbf: begin outa = 10'h075; end
-        8'hc0: begin outa = 10'h3c4; end
-        8'hc1: begin outa = 10'h2cc; end
-        8'hc2: begin outa = 10'h123; end
-        8'hc3: begin outa = 10'h3fd; end
-        8'hc4: begin outa = 10'h11e; end
-        8'hc5: begin outa = 10'h27c; end
-        8'hc6: begin outa = 10'h1e2; end
-        8'hc7: begin outa = 10'h377; end
-        8'hc8: begin outa = 10'h33a; end
-        8'hc9: begin outa = 10'h32d; end
-        8'hca: begin outa = 10'h014; end
-        8'hcb: begin outa = 10'h332; end
-        8'hcc: begin outa = 10'h359; end
-        8'hcd: begin outa = 10'h0a4; end
-        8'hce: begin outa = 10'h348; end
-        8'hcf: begin outa = 10'h04b; end
-        8'hd0: begin outa = 10'h147; end
-        8'hd1: begin outa = 10'h026; end
-        8'hd2: begin outa = 10'h103; end
-        8'hd3: begin outa = 10'h106; end
-        8'hd4: begin outa = 10'h35a; end
-        8'hd5: begin outa = 10'h254; end
-        8'hd6: begin outa = 10'h0cd; end
-        8'hd7: begin outa = 10'h17c; end
-        8'hd8: begin outa = 10'h37e; end
-        8'hd9: begin outa = 10'h0a9; end
-        8'hda: begin outa = 10'h0fe; end
-        8'hdb: begin outa = 10'h3c0; end
-        8'hdc: begin outa = 10'h1d9; end
-        8'hdd: begin outa = 10'h10e; end
-        8'hde: begin outa = 10'h394; end
-        8'hdf: begin outa = 10'h316; end
-        8'he0: begin outa = 10'h05b; end
-        8'he1: begin outa = 10'h126; end
-        8'he2: begin outa = 10'h369; end
-        8'he3: begin outa = 10'h291; end
-        8'he4: begin outa = 10'h2ca; end
-        8'he5: begin outa = 10'h25b; end
-        8'he6: begin outa = 10'h106; end
-        8'he7: begin outa = 10'h172; end
-        8'he8: begin outa = 10'h2f7; end
-        8'he9: begin outa = 10'h2d3; end
-        8'hea: begin outa = 10'h182; end
-        8'heb: begin outa = 10'h327; end
-        8'hec: begin outa = 10'h1d0; end
-        8'hed: begin outa = 10'h204; end
-        8'hee: begin outa = 10'h11f; end
-        8'hef: begin outa = 10'h365; end
-        8'hf0: begin outa = 10'h2c2; end
-        8'hf1: begin outa = 10'h2b5; end
-        8'hf2: begin outa = 10'h1f8; end
-        8'hf3: begin outa = 10'h2a7; end
-        8'hf4: begin outa = 10'h1be; end
-        8'hf5: begin outa = 10'h25e; end
-        8'hf6: begin outa = 10'h032; end
-        8'hf7: begin outa = 10'h2ef; end
-        8'hf8: begin outa = 10'h02f; end
-        8'hf9: begin outa = 10'h201; end
-        8'hfa: begin outa = 10'h054; end
-        8'hfb: begin outa = 10'h013; end
-        8'hfc: begin outa = 10'h249; end
-        8'hfd: begin outa = 10'h09a; end
-        8'hfe: begin outa = 10'h012; end
-        8'hff: begin outa = 10'h114; end
-      endcase
-   end
+      8'h01: outa = 10'h318;
+      8'h02: outa = 10'h29f;
+      8'h03: outa = 10'h392;
+      8'h04: outa = 10'h1ef;
+      8'h05: outa = 10'h06c;
+      8'h06: outa = 10'h29f;
+      8'h07: outa = 10'h29a;
+      8'h08: outa = 10'h3ce;
+      8'h09: outa = 10'h37c;
+      8'h0a: outa = 10'h058;
+      8'h0b: outa = 10'h3b2;
+      8'h0c: outa = 10'h36f;
+      8'h0d: outa = 10'h2c5;
+      8'h0e: outa = 10'h23a;
+      8'h0f: outa = 10'h222;
+      8'h10: outa = 10'h328;
+      8'h11: outa = 10'h3c3;
+      8'h12: outa = 10'h12c;
+      8'h13: outa = 10'h1d0;
+      8'h14: outa = 10'h3ff;
+      8'h15: outa = 10'h115;
+      8'h16: outa = 10'h3ba;
+      8'h17: outa = 10'h3ba;
+      8'h18: outa = 10'h10d;
+      8'h19: outa = 10'h13b;
+      8'h1a: outa = 10'h0a0;
+      8'h1b: outa = 10'h264;
+      8'h1c: outa = 10'h3a2;
+      8'h1d: outa = 10'h07c;
+      8'h1e: outa = 10'h291;
+      8'h1f: outa = 10'h1d1;
+      8'h20: outa = 10'h354;
+      8'h21: outa = 10'h0c0;
+      8'h22: outa = 10'h191;
+      8'h23: outa = 10'h379;
+      8'h24: outa = 10'h073;
+      8'h25: outa = 10'h2fd;
+      8'h26: outa = 10'h2e0;
+      8'h27: outa = 10'h337;
+      8'h28: outa = 10'h2c7;
+      8'h29: outa = 10'h19e;
+      8'h2a: outa = 10'h107;
+      8'h2b: outa = 10'h06a;
+      8'h2c: outa = 10'h1c7;
+      8'h2d: outa = 10'h107;
+      8'h2e: outa = 10'h0cf;
+      8'h2f: outa = 10'h009;
+      8'h30: outa = 10'h09d;
+      8'h31: outa = 10'h28e;
+      8'h32: outa = 10'h010;
+      8'h33: outa = 10'h1e0;
+      8'h34: outa = 10'h079;
+      8'h35: outa = 10'h13e;
+      8'h36: outa = 10'h282;
+      8'h37: outa = 10'h21c;
+      8'h38: outa = 10'h148;
+      8'h39: outa = 10'h3c0;
+      8'h3a: outa = 10'h176;
+      8'h3b: outa = 10'h3fc;
+      8'h3c: outa = 10'h295;
+      8'h3d: outa = 10'h113;
+      8'h3e: outa = 10'h354;
+      8'h3f: outa = 10'h0db;
+      8'h40: outa = 10'h238;
+      8'h41: outa = 10'h12b;
+      8'h42: outa = 10'h1dc;
+      8'h43: outa = 10'h137;
+      8'h44: outa = 10'h1e2;
+      8'h45: outa = 10'h3d5;
+      8'h46: outa = 10'h30c;
+      8'h47: outa = 10'h298;
+      8'h48: outa = 10'h080;
+      8'h49: outa = 10'h35a;
+      8'h4a: outa = 10'h01b;
+      8'h4b: outa = 10'h0a3;
+      8'h4c: outa = 10'h0b3;
+      8'h4d: outa = 10'h17a;
+      8'h4e: outa = 10'h3ae;
+      8'h4f: outa = 10'h078;
+      8'h50: outa = 10'h322;
+      8'h51: outa = 10'h213;
+      8'h52: outa = 10'h11a;
+      8'h53: outa = 10'h1a7;
+      8'h54: outa = 10'h35a;
+      8'h55: outa = 10'h233;
+      8'h56: outa = 10'h01d;
+      8'h57: outa = 10'h2d5;
+      8'h58: outa = 10'h1a0;
+      8'h59: outa = 10'h3d0;
+      8'h5a: outa = 10'h181;
+      8'h5b: outa = 10'h219;
+      8'h5c: outa = 10'h26a;
+      8'h5d: outa = 10'h050;
+      8'h5e: outa = 10'h189;
+      8'h5f: outa = 10'h1eb;
+      8'h60: outa = 10'h224;
+      8'h61: outa = 10'h2fe;
+      8'h62: outa = 10'h0ae;
+      8'h63: outa = 10'h1cd;
+      8'h64: outa = 10'h273;
+      8'h65: outa = 10'h268;
+      8'h66: outa = 10'h111;
+      8'h67: outa = 10'h1f9;
+      8'h68: outa = 10'h232;
+      8'h69: outa = 10'h255;
+      8'h6a: outa = 10'h34c;
+      8'h6b: outa = 10'h049;
+      8'h6c: outa = 10'h197;
+      8'h6d: outa = 10'h0fe;
+      8'h6e: outa = 10'h253;
+      8'h6f: outa = 10'h2de;
+      8'h70: outa = 10'h13b;
+      8'h71: outa = 10'h040;
+      8'h72: outa = 10'h0b4;
+      8'h73: outa = 10'h233;
+      8'h74: outa = 10'h198;
+      8'h75: outa = 10'h018;
+      8'h76: outa = 10'h2f7;
+      8'h77: outa = 10'h134;
+      8'h78: outa = 10'h1ca;
+      8'h79: outa = 10'h286;
+      8'h7a: outa = 10'h0e6;
+      8'h7b: outa = 10'h064;
+      8'h7c: outa = 10'h257;
+      8'h7d: outa = 10'h31a;
+      8'h7e: outa = 10'h247;
+      8'h7f: outa = 10'h299;
+      8'h80: outa = 10'h02c;
+      8'h81: outa = 10'h2bb;
+      8'h82: outa = 10'h180;
+      8'h83: outa = 10'h245;
+      8'h84: outa = 10'h0da;
+      8'h85: outa = 10'h367;
+      8'h86: outa = 10'h304;
+      8'h87: outa = 10'h38b;
+      8'h88: outa = 10'h09f;
+      8'h89: outa = 10'h1f0;
+      8'h8a: outa = 10'h281;
+      8'h8b: outa = 10'h019;
+      8'h8c: outa = 10'h1f2;
+      8'h8d: outa = 10'h0b1;
+      8'h8e: outa = 10'h058;
+      8'h8f: outa = 10'h39b;
+      8'h90: outa = 10'h2ec;
+      8'h91: outa = 10'h250;
+      8'h92: outa = 10'h3f4;
+      8'h93: outa = 10'h057;
+      8'h94: outa = 10'h18f;
+      8'h95: outa = 10'h105;
+      8'h96: outa = 10'h1ae;
+      8'h97: outa = 10'h04e;
+      8'h98: outa = 10'h240;
+      8'h99: outa = 10'h3e4;
+      8'h9a: outa = 10'h3c6;
+      8'h9b: outa = 10'h109;
+      8'h9c: outa = 10'h073;
+      8'h9d: outa = 10'h19f;
+      8'h9e: outa = 10'h3b8;
+      8'h9f: outa = 10'h00e;
+      8'ha0: outa = 10'h1b3;
+      8'ha1: outa = 10'h2bd;
+      8'ha2: outa = 10'h324;
+      8'ha3: outa = 10'h343;
+      8'ha4: outa = 10'h1c9;
+      8'ha5: outa = 10'h185;
+      8'ha6: outa = 10'h37a;
+      8'ha7: outa = 10'h0e0;
+      8'ha8: outa = 10'h0a3;
+      8'ha9: outa = 10'h019;
+      8'haa: outa = 10'h099;
+      8'hab: outa = 10'h376;
+      8'hac: outa = 10'h077;
+      8'had: outa = 10'h2b1;
+      8'hae: outa = 10'h27f;
+      8'haf: outa = 10'h265;
+      8'hb0: outa = 10'h156;
+      8'hb1: outa = 10'h1ce;
+      8'hb2: outa = 10'h008;
+      8'hb3: outa = 10'h12e;
+      8'hb4: outa = 10'h199;
+      8'hb5: outa = 10'h330;
+      8'hb6: outa = 10'h1ab;
+      8'hb7: outa = 10'h3bd;
+      8'hb8: outa = 10'h0ca;
+      8'hb9: outa = 10'h367;
+      8'hba: outa = 10'h334;
+      8'hbb: outa = 10'h040;
+      8'hbc: outa = 10'h1a7;
+      8'hbd: outa = 10'h036;
+      8'hbe: outa = 10'h223;
+      8'hbf: outa = 10'h075;
+      8'hc0: outa = 10'h3c4;
+      8'hc1: outa = 10'h2cc;
+      8'hc2: outa = 10'h123;
+      8'hc3: outa = 10'h3fd;
+      8'hc4: outa = 10'h11e;
+      8'hc5: outa = 10'h27c;
+      8'hc6: outa = 10'h1e2;
+      8'hc7: outa = 10'h377;
+      8'hc8: outa = 10'h33a;
+      8'hc9: outa = 10'h32d;
+      8'hca: outa = 10'h014;
+      8'hcb: outa = 10'h332;
+      8'hcc: outa = 10'h359;
+      8'hcd: outa = 10'h0a4;
+      8'hce: outa = 10'h348;
+      8'hcf: outa = 10'h04b;
+      8'hd0: outa = 10'h147;
+      8'hd1: outa = 10'h026;
+      8'hd2: outa = 10'h103;
+      8'hd3: outa = 10'h106;
+      8'hd4: outa = 10'h35a;
+      8'hd5: outa = 10'h254;
+      8'hd6: outa = 10'h0cd;
+      8'hd7: outa = 10'h17c;
+      8'hd8: outa = 10'h37e;
+      8'hd9: outa = 10'h0a9;
+      8'hda: outa = 10'h0fe;
+      8'hdb: outa = 10'h3c0;
+      8'hdc: outa = 10'h1d9;
+      8'hdd: outa = 10'h10e;
+      8'hde: outa = 10'h394;
+      8'hdf: outa = 10'h316;
+      8'he0: outa = 10'h05b;
+      8'he1: outa = 10'h126;
+      8'he2: outa = 10'h369;
+      8'he3: outa = 10'h291;
+      8'he4: outa = 10'h2ca;
+      8'he5: outa = 10'h25b;
+      8'he6: outa = 10'h106;
+      8'he7: outa = 10'h172;
+      8'he8: outa = 10'h2f7;
+      8'he9: outa = 10'h2d3;
+      8'hea: outa = 10'h182;
+      8'heb: outa = 10'h327;
+      8'hec: outa = 10'h1d0;
+      8'hed: outa = 10'h204;
+      8'hee: outa = 10'h11f;
+      8'hef: outa = 10'h365;
+      8'hf0: outa = 10'h2c2;
+      8'hf1: outa = 10'h2b5;
+      8'hf2: outa = 10'h1f8;
+      8'hf3: outa = 10'h2a7;
+      8'hf4: outa = 10'h1be;
+      8'hf5: outa = 10'h25e;
+      8'hf6: outa = 10'h032;
+      8'hf7: outa = 10'h2ef;
+      8'hf8: outa = 10'h02f;
+      8'hf9: outa = 10'h201;
+      8'hfa: outa = 10'h054;
+      8'hfb: outa = 10'h013;
+      8'hfc: outa = 10'h249;
+      8'hfd: outa = 10'h09a;
+      8'hfe: outa = 10'h012;
+      8'hff: outa = 10'h114;
+    endcase
+  end
 endmodule

test_regress/t/t_case_huge_sub3.v

@@ -5,289 +5,285 @@
 // SPDX-License-Identifier: CC0-1.0
 
 module t_case_huge_sub3 (/*AUTOARG*/
-   // Outputs
-   outr,
-   // Inputs
-   clk, index
-   );
+  // Outputs
+  outr,
+  // Inputs
+  clk, index
+  );
 
-   input clk;
-   input [9:0] index;
-   output [3:0] outr;
+  input clk;
+  input [9:0] index;
+  output logic [3:0] outr;
 
-   // =============================
-   /*AUTOREG*/
-   // Beginning of automatic regs (for this module's undeclared outputs)
-   reg [3:0]            outr;
-   // End of automatics
+  // =============================
+  // Created from Pthon3:
+  // for i in range(256):
+  //    print("      8'h%02x: begin outr <= outr^index[8:5]^4'h%01x; end"
+  //        % (i, random.randint(0,15)))
 
-   // =============================
-   // Created from Pthon3:
-   // for i in range(256):
-   //     print("        8'h%02x: begin outr <= outr^index[8:5]^4'h%01x; end"
-   //           % (i, random.randint(0,15)))
+  // Reset cheating
+  initial outr = 4'b0;
 
-   // Reset cheating
-   initial outr = 4'b0;
-
-   always @(posedge clk) begin
-      case (index[7:0])
-        8'h00: begin outr <= 4'h0; end
-        8'h01: begin /*No Change*/ end
-        8'h02: begin outr <= outr^index[8:5]^4'ha; end
-        8'h03: begin outr <= outr^index[8:5]^4'h4; end
-        8'h04: begin outr <= outr^index[8:5]^4'hd; end
-        8'h05: begin outr <= outr^index[8:5]^4'h1; end
-        8'h06: begin outr <= outr^index[8:5]^4'hf; end
-        8'h07: begin outr <= outr^index[8:5]^4'he; end
-        8'h08: begin outr <= outr^index[8:5]^4'h0; end
-        8'h09: begin outr <= outr^index[8:5]^4'h4; end
-        8'h0a: begin outr <= outr^index[8:5]^4'h5; end
-        8'h0b: begin outr <= outr^index[8:5]^4'ha; end
-        8'h0c: begin outr <= outr^index[8:5]^4'h2; end
-        8'h0d: begin outr <= outr^index[8:5]^4'hf; end
-        8'h0e: begin outr <= outr^index[8:5]^4'h5; end
-        8'h0f: begin outr <= outr^index[8:5]^4'h0; end
-        8'h10: begin outr <= outr^index[8:5]^4'h3; end
-        8'h11: begin outr <= outr^index[8:5]^4'hb; end
-        8'h12: begin outr <= outr^index[8:5]^4'h0; end
-        8'h13: begin outr <= outr^index[8:5]^4'hf; end
-        8'h14: begin outr <= outr^index[8:5]^4'h3; end
-        8'h15: begin outr <= outr^index[8:5]^4'h5; end
-        8'h16: begin outr <= outr^index[8:5]^4'h7; end
-        8'h17: begin outr <= outr^index[8:5]^4'h2; end
-        8'h18: begin outr <= outr^index[8:5]^4'h3; end
-        8'h19: begin outr <= outr^index[8:5]^4'hb; end
-        8'h1a: begin outr <= outr^index[8:5]^4'h5; end
-        8'h1b: begin outr <= outr^index[8:5]^4'h4; end
-        8'h1c: begin outr <= outr^index[8:5]^4'h2; end
-        8'h1d: begin outr <= outr^index[8:5]^4'hf; end
-        8'h1e: begin outr <= outr^index[8:5]^4'h0; end
-        8'h1f: begin outr <= outr^index[8:5]^4'h4; end
-        8'h20: begin outr <= outr^index[8:5]^4'h6; end
-        8'h21: begin outr <= outr^index[8:5]^4'ha; end
-        8'h22: begin outr <= outr^index[8:5]^4'h6; end
-        8'h23: begin outr <= outr^index[8:5]^4'hb; end
-        8'h24: begin outr <= outr^index[8:5]^4'ha; end
-        8'h25: begin outr <= outr^index[8:5]^4'he; end
-        8'h26: begin outr <= outr^index[8:5]^4'h7; end
-        8'h27: begin outr <= outr^index[8:5]^4'ha; end
-        8'h28: begin outr <= outr^index[8:5]^4'h3; end
-        8'h29: begin outr <= outr^index[8:5]^4'h8; end
-        8'h2a: begin outr <= outr^index[8:5]^4'h1; end
-        8'h2b: begin outr <= outr^index[8:5]^4'h8; end
-        8'h2c: begin outr <= outr^index[8:5]^4'h4; end
-        8'h2d: begin outr <= outr^index[8:5]^4'h4; end
-        8'h2e: begin outr <= outr^index[8:5]^4'he; end
-        8'h2f: begin outr <= outr^index[8:5]^4'h8; end
-        8'h30: begin outr <= outr^index[8:5]^4'ha; end
-        8'h31: begin outr <= outr^index[8:5]^4'h7; end
-        8'h32: begin outr <= outr^index[8:5]^4'h0; end
-        8'h33: begin outr <= outr^index[8:5]^4'h3; end
-        8'h34: begin outr <= outr^index[8:5]^4'h1; end
-        8'h35: begin outr <= outr^index[8:5]^4'h3; end
-        8'h36: begin outr <= outr^index[8:5]^4'h4; end
-        8'h37: begin outr <= outr^index[8:5]^4'h6; end
-        8'h38: begin outr <= outr^index[8:5]^4'h4; end
-        8'h39: begin outr <= outr^index[8:5]^4'hb; end
-        8'h3a: begin outr <= outr^index[8:5]^4'h7; end
-        8'h3b: begin outr <= outr^index[8:5]^4'h1; end
-        8'h3c: begin outr <= outr^index[8:5]^4'h2; end
-        8'h3d: begin outr <= outr^index[8:5]^4'h0; end
-        8'h3e: begin outr <= outr^index[8:5]^4'h2; end
-        8'h3f: begin outr <= outr^index[8:5]^4'ha; end
-        8'h40: begin outr <= outr^index[8:5]^4'h7; end
-        8'h41: begin outr <= outr^index[8:5]^4'h5; end
-        8'h42: begin outr <= outr^index[8:5]^4'h5; end
-        8'h43: begin outr <= outr^index[8:5]^4'h4; end
-        8'h44: begin outr <= outr^index[8:5]^4'h8; end
-        8'h45: begin outr <= outr^index[8:5]^4'h5; end
-        8'h46: begin outr <= outr^index[8:5]^4'hf; end
-        8'h47: begin outr <= outr^index[8:5]^4'h6; end
-        8'h48: begin outr <= outr^index[8:5]^4'h7; end
-        8'h49: begin outr <= outr^index[8:5]^4'h4; end
-        8'h4a: begin outr <= outr^index[8:5]^4'ha; end
-        8'h4b: begin outr <= outr^index[8:5]^4'hd; end
-        8'h4c: begin outr <= outr^index[8:5]^4'hb; end
-        8'h4d: begin outr <= outr^index[8:5]^4'hf; end
-        8'h4e: begin outr <= outr^index[8:5]^4'hd; end
-        8'h4f: begin outr <= outr^index[8:5]^4'h7; end
-        8'h50: begin outr <= outr^index[8:5]^4'h9; end
-        8'h51: begin outr <= outr^index[8:5]^4'ha; end
-        8'h52: begin outr <= outr^index[8:5]^4'hf; end
-        8'h53: begin outr <= outr^index[8:5]^4'h3; end
-        8'h54: begin outr <= outr^index[8:5]^4'h1; end
-        8'h55: begin outr <= outr^index[8:5]^4'h0; end
-        8'h56: begin outr <= outr^index[8:5]^4'h2; end
-        8'h57: begin outr <= outr^index[8:5]^4'h9; end
-        8'h58: begin outr <= outr^index[8:5]^4'h2; end
-        8'h59: begin outr <= outr^index[8:5]^4'h4; end
-        8'h5a: begin outr <= outr^index[8:5]^4'hc; end
-        8'h5b: begin outr <= outr^index[8:5]^4'hd; end
-        8'h5c: begin outr <= outr^index[8:5]^4'h3; end
-        8'h5d: begin outr <= outr^index[8:5]^4'hb; end
-        8'h5e: begin outr <= outr^index[8:5]^4'hd; end
-        8'h5f: begin outr <= outr^index[8:5]^4'h7; end
-        8'h60: begin outr <= outr^index[8:5]^4'h7; end
-        8'h61: begin outr <= outr^index[8:5]^4'h3; end
-        8'h62: begin outr <= outr^index[8:5]^4'h3; end
-        8'h63: begin outr <= outr^index[8:5]^4'hb; end
-        8'h64: begin outr <= outr^index[8:5]^4'h9; end
-        8'h65: begin outr <= outr^index[8:5]^4'h4; end
-        8'h66: begin outr <= outr^index[8:5]^4'h3; end
-        8'h67: begin outr <= outr^index[8:5]^4'h6; end
-        8'h68: begin outr <= outr^index[8:5]^4'h7; end
-        8'h69: begin outr <= outr^index[8:5]^4'h7; end
-        8'h6a: begin outr <= outr^index[8:5]^4'hf; end
-        8'h6b: begin outr <= outr^index[8:5]^4'h6; end
-        8'h6c: begin outr <= outr^index[8:5]^4'h8; end
-        8'h6d: begin outr <= outr^index[8:5]^4'he; end
-        8'h6e: begin outr <= outr^index[8:5]^4'h4; end
-        8'h6f: begin outr <= outr^index[8:5]^4'h6; end
-        8'h70: begin outr <= outr^index[8:5]^4'hc; end
-        8'h71: begin outr <= outr^index[8:5]^4'h9; end
-        8'h72: begin outr <= outr^index[8:5]^4'h5; end
-        8'h73: begin outr <= outr^index[8:5]^4'ha; end
-        8'h74: begin outr <= outr^index[8:5]^4'h7; end
-        8'h75: begin outr <= outr^index[8:5]^4'h0; end
-        8'h76: begin outr <= outr^index[8:5]^4'h1; end
-        8'h77: begin outr <= outr^index[8:5]^4'he; end
-        8'h78: begin outr <= outr^index[8:5]^4'ha; end
-        8'h79: begin outr <= outr^index[8:5]^4'h7; end
-        8'h7a: begin outr <= outr^index[8:5]^4'hf; end
-        8'h7b: begin outr <= outr^index[8:5]^4'he; end
-        8'h7c: begin outr <= outr^index[8:5]^4'h6; end
-        8'h7d: begin outr <= outr^index[8:5]^4'hc; end
-        8'h7e: begin outr <= outr^index[8:5]^4'hc; end
-        8'h7f: begin outr <= outr^index[8:5]^4'h0; end
-        8'h80: begin outr <= outr^index[8:5]^4'h0; end
-        8'h81: begin outr <= outr^index[8:5]^4'hd; end
-        8'h82: begin outr <= outr^index[8:5]^4'hb; end
-        8'h83: begin outr <= outr^index[8:5]^4'hc; end
-        8'h84: begin outr <= outr^index[8:5]^4'h2; end
-        8'h85: begin outr <= outr^index[8:5]^4'h8; end
-        8'h86: begin outr <= outr^index[8:5]^4'h3; end
-        8'h87: begin outr <= outr^index[8:5]^4'ha; end
-        8'h88: begin outr <= outr^index[8:5]^4'he; end
-        8'h89: begin outr <= outr^index[8:5]^4'h9; end
-        8'h8a: begin outr <= outr^index[8:5]^4'h1; end
-        8'h8b: begin outr <= outr^index[8:5]^4'h1; end
-        8'h8c: begin outr <= outr^index[8:5]^4'hc; end
-        8'h8d: begin outr <= outr^index[8:5]^4'h2; end
-        8'h8e: begin outr <= outr^index[8:5]^4'h2; end
-        8'h8f: begin outr <= outr^index[8:5]^4'hd; end
-        8'h90: begin outr <= outr^index[8:5]^4'h0; end
-        8'h91: begin outr <= outr^index[8:5]^4'h6; end
-        8'h92: begin outr <= outr^index[8:5]^4'h7; end
-        8'h93: begin outr <= outr^index[8:5]^4'hc; end
-        8'h94: begin outr <= outr^index[8:5]^4'hb; end
-        8'h95: begin outr <= outr^index[8:5]^4'h3; end
-        8'h96: begin outr <= outr^index[8:5]^4'h0; end
-        8'h97: begin outr <= outr^index[8:5]^4'hc; end
-        8'h98: begin outr <= outr^index[8:5]^4'hc; end
-        8'h99: begin outr <= outr^index[8:5]^4'hb; end
-        8'h9a: begin outr <= outr^index[8:5]^4'h6; end
-        8'h9b: begin outr <= outr^index[8:5]^4'h5; end
-        8'h9c: begin outr <= outr^index[8:5]^4'h5; end
-        8'h9d: begin outr <= outr^index[8:5]^4'h4; end
-        8'h9e: begin outr <= outr^index[8:5]^4'h7; end
-        8'h9f: begin outr <= outr^index[8:5]^4'he; end
-        8'ha0: begin outr <= outr^index[8:5]^4'hc; end
-        8'ha1: begin outr <= outr^index[8:5]^4'hc; end
-        8'ha2: begin outr <= outr^index[8:5]^4'h0; end
-        8'ha3: begin outr <= outr^index[8:5]^4'h1; end
-        8'ha4: begin outr <= outr^index[8:5]^4'hd; end
-        8'ha5: begin outr <= outr^index[8:5]^4'h3; end
-        8'ha6: begin outr <= outr^index[8:5]^4'hc; end
-        8'ha7: begin outr <= outr^index[8:5]^4'h2; end
-        8'ha8: begin outr <= outr^index[8:5]^4'h3; end
-        8'ha9: begin outr <= outr^index[8:5]^4'hd; end
-        8'haa: begin outr <= outr^index[8:5]^4'h5; end
-        8'hab: begin outr <= outr^index[8:5]^4'hb; end
-        8'hac: begin outr <= outr^index[8:5]^4'he; end
-        8'had: begin outr <= outr^index[8:5]^4'h0; end
-        8'hae: begin outr <= outr^index[8:5]^4'hf; end
-        8'haf: begin outr <= outr^index[8:5]^4'h9; end
-        8'hb0: begin outr <= outr^index[8:5]^4'hf; end
-        8'hb1: begin outr <= outr^index[8:5]^4'h7; end
-        8'hb2: begin outr <= outr^index[8:5]^4'h9; end
-        8'hb3: begin outr <= outr^index[8:5]^4'hf; end
-        8'hb4: begin outr <= outr^index[8:5]^4'he; end
-        8'hb5: begin outr <= outr^index[8:5]^4'h3; end
-        8'hb6: begin outr <= outr^index[8:5]^4'he; end
-        8'hb7: begin outr <= outr^index[8:5]^4'h8; end
-        8'hb8: begin outr <= outr^index[8:5]^4'hf; end
-        8'hb9: begin outr <= outr^index[8:5]^4'hd; end
-        8'hba: begin outr <= outr^index[8:5]^4'h3; end
-        8'hbb: begin outr <= outr^index[8:5]^4'h5; end
-        8'hbc: begin outr <= outr^index[8:5]^4'hd; end
-        8'hbd: begin outr <= outr^index[8:5]^4'ha; end
-        8'hbe: begin outr <= outr^index[8:5]^4'h7; end
-        8'hbf: begin outr <= outr^index[8:5]^4'he; end
-        8'hc0: begin outr <= outr^index[8:5]^4'h2; end
-        8'hc1: begin outr <= outr^index[8:5]^4'he; end
-        8'hc2: begin outr <= outr^index[8:5]^4'h9; end
-        8'hc3: begin outr <= outr^index[8:5]^4'hb; end
-        8'hc4: begin outr <= outr^index[8:5]^4'h0; end
-        8'hc5: begin outr <= outr^index[8:5]^4'h5; end
-        8'hc6: begin outr <= outr^index[8:5]^4'h9; end
-        8'hc7: begin outr <= outr^index[8:5]^4'h6; end
-        8'hc8: begin outr <= outr^index[8:5]^4'ha; end
-        8'hc9: begin outr <= outr^index[8:5]^4'hf; end
-        8'hca: begin outr <= outr^index[8:5]^4'h3; end
-        8'hcb: begin outr <= outr^index[8:5]^4'hb; end
-        8'hcc: begin outr <= outr^index[8:5]^4'he; end
-        8'hcd: begin outr <= outr^index[8:5]^4'h2; end
-        8'hce: begin outr <= outr^index[8:5]^4'h5; end
-        8'hcf: begin outr <= outr^index[8:5]^4'hf; end
-        8'hd0: begin outr <= outr^index[8:5]^4'h2; end
-        8'hd1: begin outr <= outr^index[8:5]^4'h9; end
-        8'hd2: begin outr <= outr^index[8:5]^4'hb; end
-        8'hd3: begin outr <= outr^index[8:5]^4'h8; end
-        8'hd4: begin outr <= outr^index[8:5]^4'h0; end
-        8'hd5: begin outr <= outr^index[8:5]^4'h2; end
-        8'hd6: begin outr <= outr^index[8:5]^4'hb; end
-        8'hd7: begin outr <= outr^index[8:5]^4'h2; end
-        8'hd8: begin outr <= outr^index[8:5]^4'ha; end
-        8'hd9: begin outr <= outr^index[8:5]^4'hf; end
-        8'hda: begin outr <= outr^index[8:5]^4'h8; end
-        8'hdb: begin outr <= outr^index[8:5]^4'h4; end
-        8'hdc: begin outr <= outr^index[8:5]^4'he; end
-        8'hdd: begin outr <= outr^index[8:5]^4'h6; end
-        8'hde: begin outr <= outr^index[8:5]^4'h9; end
-        8'hdf: begin outr <= outr^index[8:5]^4'h9; end
-        8'he0: begin outr <= outr^index[8:5]^4'h7; end
-        8'he1: begin outr <= outr^index[8:5]^4'h0; end
-        8'he2: begin outr <= outr^index[8:5]^4'h9; end
-        8'he3: begin outr <= outr^index[8:5]^4'h3; end
-        8'he4: begin outr <= outr^index[8:5]^4'h2; end
-        8'he5: begin outr <= outr^index[8:5]^4'h4; end
-        8'he6: begin outr <= outr^index[8:5]^4'h5; end
-        8'he7: begin outr <= outr^index[8:5]^4'h5; end
-        8'he8: begin outr <= outr^index[8:5]^4'hf; end
-        8'he9: begin outr <= outr^index[8:5]^4'ha; end
-        8'hea: begin outr <= outr^index[8:5]^4'hc; end
-        8'heb: begin outr <= outr^index[8:5]^4'hd; end
-        8'hec: begin outr <= outr^index[8:5]^4'h1; end
-        8'hed: begin outr <= outr^index[8:5]^4'h5; end
-        8'hee: begin outr <= outr^index[8:5]^4'h9; end
-        8'hef: begin outr <= outr^index[8:5]^4'h0; end
-        8'hf0: begin outr <= outr^index[8:5]^4'hd; end
-        8'hf1: begin outr <= outr^index[8:5]^4'hf; end
-        8'hf2: begin outr <= outr^index[8:5]^4'h4; end
-        8'hf3: begin outr <= outr^index[8:5]^4'ha; end
-        8'hf4: begin outr <= outr^index[8:5]^4'h8; end
-        8'hf5: begin outr <= outr^index[8:5]^4'he; end
-        8'hf6: begin outr <= outr^index[8:5]^4'he; end
-        8'hf7: begin outr <= outr^index[8:5]^4'h1; end
-        8'hf8: begin outr <= outr^index[8:5]^4'h6; end
-        8'hf9: begin outr <= outr^index[8:5]^4'h0; end
-        8'hfa: begin outr <= outr^index[8:5]^4'h5; end
-        8'hfb: begin outr <= outr^index[8:5]^4'h1; end
-        8'hfc: begin outr <= outr^index[8:5]^4'h8; end
-        8'hfd: begin outr <= outr^index[8:5]^4'h6; end
-        8'hfe: begin outr <= outr^index[8:5]^4'h1; end
-        default: begin outr <= outr^index[8:5]^4'h6; end
-      endcase
-   end
+  always @(posedge clk) begin
+    // verilog_format: off
+    case (index[7:0])
+      8'h00: begin outr <= 4'h0; end
+      8'h01: begin /*No Change*/ end
+      8'h02: begin outr <= outr^index[8:5]^4'ha; end
+      8'h03: begin outr <= outr^index[8:5]^4'h4; end
+      8'h04: begin outr <= outr^index[8:5]^4'hd; end
+      8'h05: begin outr <= outr^index[8:5]^4'h1; end
+      8'h06: begin outr <= outr^index[8:5]^4'hf; end
+      8'h07: begin outr <= outr^index[8:5]^4'he; end
+      8'h08: begin outr <= outr^index[8:5]^4'h0; end
+      8'h09: begin outr <= outr^index[8:5]^4'h4; end
+      8'h0a: begin outr <= outr^index[8:5]^4'h5; end
+      8'h0b: begin outr <= outr^index[8:5]^4'ha; end
+      8'h0c: begin outr <= outr^index[8:5]^4'h2; end
+      8'h0d: begin outr <= outr^index[8:5]^4'hf; end
+      8'h0e: begin outr <= outr^index[8:5]^4'h5; end
+      8'h0f: begin outr <= outr^index[8:5]^4'h0; end
+      8'h10: begin outr <= outr^index[8:5]^4'h3; end
+      8'h11: begin outr <= outr^index[8:5]^4'hb; end
+      8'h12: begin outr <= outr^index[8:5]^4'h0; end
+      8'h13: begin outr <= outr^index[8:5]^4'hf; end
+      8'h14: begin outr <= outr^index[8:5]^4'h3; end
+      8'h15: begin outr <= outr^index[8:5]^4'h5; end
+      8'h16: begin outr <= outr^index[8:5]^4'h7; end
+      8'h17: begin outr <= outr^index[8:5]^4'h2; end
+      8'h18: begin outr <= outr^index[8:5]^4'h3; end
+      8'h19: begin outr <= outr^index[8:5]^4'hb; end
+      8'h1a: begin outr <= outr^index[8:5]^4'h5; end
+      8'h1b: begin outr <= outr^index[8:5]^4'h4; end
+      8'h1c: begin outr <= outr^index[8:5]^4'h2; end
+      8'h1d: begin outr <= outr^index[8:5]^4'hf; end
+      8'h1e: begin outr <= outr^index[8:5]^4'h0; end
+      8'h1f: begin outr <= outr^index[8:5]^4'h4; end
+      8'h20: begin outr <= outr^index[8:5]^4'h6; end
+      8'h21: begin outr <= outr^index[8:5]^4'ha; end
+      8'h22: begin outr <= outr^index[8:5]^4'h6; end
+      8'h23: begin outr <= outr^index[8:5]^4'hb; end
+      8'h24: begin outr <= outr^index[8:5]^4'ha; end
+      8'h25: begin outr <= outr^index[8:5]^4'he; end
+      8'h26: begin outr <= outr^index[8:5]^4'h7; end
+      8'h27: begin outr <= outr^index[8:5]^4'ha; end
+      8'h28: begin outr <= outr^index[8:5]^4'h3; end
+      8'h29: begin outr <= outr^index[8:5]^4'h8; end
+      8'h2a: begin outr <= outr^index[8:5]^4'h1; end
+      8'h2b: begin outr <= outr^index[8:5]^4'h8; end
+      8'h2c: begin outr <= outr^index[8:5]^4'h4; end
+      8'h2d: begin outr <= outr^index[8:5]^4'h4; end
+      8'h2e: begin outr <= outr^index[8:5]^4'he; end
+      8'h2f: begin outr <= outr^index[8:5]^4'h8; end
+      8'h30: begin outr <= outr^index[8:5]^4'ha; end
+      8'h31: begin outr <= outr^index[8:5]^4'h7; end
+      8'h32: begin outr <= outr^index[8:5]^4'h0; end
+      8'h33: begin outr <= outr^index[8:5]^4'h3; end
+      8'h34: begin outr <= outr^index[8:5]^4'h1; end
+      8'h35: begin outr <= outr^index[8:5]^4'h3; end
+      8'h36: begin outr <= outr^index[8:5]^4'h4; end
+      8'h37: begin outr <= outr^index[8:5]^4'h6; end
+      8'h38: begin outr <= outr^index[8:5]^4'h4; end
+      8'h39: begin outr <= outr^index[8:5]^4'hb; end
+      8'h3a: begin outr <= outr^index[8:5]^4'h7; end
+      8'h3b: begin outr <= outr^index[8:5]^4'h1; end
+      8'h3c: begin outr <= outr^index[8:5]^4'h2; end
+      8'h3d: begin outr <= outr^index[8:5]^4'h0; end
+      8'h3e: begin outr <= outr^index[8:5]^4'h2; end
+      8'h3f: begin outr <= outr^index[8:5]^4'ha; end
+      8'h40: begin outr <= outr^index[8:5]^4'h7; end
+      8'h41: begin outr <= outr^index[8:5]^4'h5; end
+      8'h42: begin outr <= outr^index[8:5]^4'h5; end
+      8'h43: begin outr <= outr^index[8:5]^4'h4; end
+      8'h44: begin outr <= outr^index[8:5]^4'h8; end
+      8'h45: begin outr <= outr^index[8:5]^4'h5; end
+      8'h46: begin outr <= outr^index[8:5]^4'hf; end
+      8'h47: begin outr <= outr^index[8:5]^4'h6; end
+      8'h48: begin outr <= outr^index[8:5]^4'h7; end
+      8'h49: begin outr <= outr^index[8:5]^4'h4; end
+      8'h4a: begin outr <= outr^index[8:5]^4'ha; end
+      8'h4b: begin outr <= outr^index[8:5]^4'hd; end
+      8'h4c: begin outr <= outr^index[8:5]^4'hb; end
+      8'h4d: begin outr <= outr^index[8:5]^4'hf; end
+      8'h4e: begin outr <= outr^index[8:5]^4'hd; end
+      8'h4f: begin outr <= outr^index[8:5]^4'h7; end
+      8'h50: begin outr <= outr^index[8:5]^4'h9; end
+      8'h51: begin outr <= outr^index[8:5]^4'ha; end
+      8'h52: begin outr <= outr^index[8:5]^4'hf; end
+      8'h53: begin outr <= outr^index[8:5]^4'h3; end
+      8'h54: begin outr <= outr^index[8:5]^4'h1; end
+      8'h55: begin outr <= outr^index[8:5]^4'h0; end
+      8'h56: begin outr <= outr^index[8:5]^4'h2; end
+      8'h57: begin outr <= outr^index[8:5]^4'h9; end
+      8'h58: begin outr <= outr^index[8:5]^4'h2; end
+      8'h59: begin outr <= outr^index[8:5]^4'h4; end
+      8'h5a: begin outr <= outr^index[8:5]^4'hc; end
+      8'h5b: begin outr <= outr^index[8:5]^4'hd; end
+      8'h5c: begin outr <= outr^index[8:5]^4'h3; end
+      8'h5d: begin outr <= outr^index[8:5]^4'hb; end
+      8'h5e: begin outr <= outr^index[8:5]^4'hd; end
+      8'h5f: begin outr <= outr^index[8:5]^4'h7; end
+      8'h60: begin outr <= outr^index[8:5]^4'h7; end
+      8'h61: begin outr <= outr^index[8:5]^4'h3; end
+      8'h62: begin outr <= outr^index[8:5]^4'h3; end
+      8'h63: begin outr <= outr^index[8:5]^4'hb; end
+      8'h64: begin outr <= outr^index[8:5]^4'h9; end
+      8'h65: begin outr <= outr^index[8:5]^4'h4; end
+      8'h66: begin outr <= outr^index[8:5]^4'h3; end
+      8'h67: begin outr <= outr^index[8:5]^4'h6; end
+      8'h68: begin outr <= outr^index[8:5]^4'h7; end
+      8'h69: begin outr <= outr^index[8:5]^4'h7; end
+      8'h6a: begin outr <= outr^index[8:5]^4'hf; end
+      8'h6b: begin outr <= outr^index[8:5]^4'h6; end
+      8'h6c: begin outr <= outr^index[8:5]^4'h8; end
+      8'h6d: begin outr <= outr^index[8:5]^4'he; end
+      8'h6e: begin outr <= outr^index[8:5]^4'h4; end
+      8'h6f: begin outr <= outr^index[8:5]^4'h6; end
+      8'h70: begin outr <= outr^index[8:5]^4'hc; end
+      8'h71: begin outr <= outr^index[8:5]^4'h9; end
+      8'h72: begin outr <= outr^index[8:5]^4'h5; end
+      8'h73: begin outr <= outr^index[8:5]^4'ha; end
+      8'h74: begin outr <= outr^index[8:5]^4'h7; end
+      8'h75: begin outr <= outr^index[8:5]^4'h0; end
+      8'h76: begin outr <= outr^index[8:5]^4'h1; end
+      8'h77: begin outr <= outr^index[8:5]^4'he; end
+      8'h78: begin outr <= outr^index[8:5]^4'ha; end
+      8'h79: begin outr <= outr^index[8:5]^4'h7; end
+      8'h7a: begin outr <= outr^index[8:5]^4'hf; end
+      8'h7b: begin outr <= outr^index[8:5]^4'he; end
+      8'h7c: begin outr <= outr^index[8:5]^4'h6; end
+      8'h7d: begin outr <= outr^index[8:5]^4'hc; end
+      8'h7e: begin outr <= outr^index[8:5]^4'hc; end
+      8'h7f: begin outr <= outr^index[8:5]^4'h0; end
+      8'h80: begin outr <= outr^index[8:5]^4'h0; end
+      8'h81: begin outr <= outr^index[8:5]^4'hd; end
+      8'h82: begin outr <= outr^index[8:5]^4'hb; end
+      8'h83: begin outr <= outr^index[8:5]^4'hc; end
+      8'h84: begin outr <= outr^index[8:5]^4'h2; end
+      8'h85: begin outr <= outr^index[8:5]^4'h8; end
+      8'h86: begin outr <= outr^index[8:5]^4'h3; end
+      8'h87: begin outr <= outr^index[8:5]^4'ha; end
+      8'h88: begin outr <= outr^index[8:5]^4'he; end
+      8'h89: begin outr <= outr^index[8:5]^4'h9; end
+      8'h8a: begin outr <= outr^index[8:5]^4'h1; end
+      8'h8b: begin outr <= outr^index[8:5]^4'h1; end
+      8'h8c: begin outr <= outr^index[8:5]^4'hc; end
+      8'h8d: begin outr <= outr^index[8:5]^4'h2; end
+      8'h8e: begin outr <= outr^index[8:5]^4'h2; end
+      8'h8f: begin outr <= outr^index[8:5]^4'hd; end
+      8'h90: begin outr <= outr^index[8:5]^4'h0; end
+      8'h91: begin outr <= outr^index[8:5]^4'h6; end
+      8'h92: begin outr <= outr^index[8:5]^4'h7; end
+      8'h93: begin outr <= outr^index[8:5]^4'hc; end
+      8'h94: begin outr <= outr^index[8:5]^4'hb; end
+      8'h95: begin outr <= outr^index[8:5]^4'h3; end
+      8'h96: begin outr <= outr^index[8:5]^4'h0; end
+      8'h97: begin outr <= outr^index[8:5]^4'hc; end
+      8'h98: begin outr <= outr^index[8:5]^4'hc; end
+      8'h99: begin outr <= outr^index[8:5]^4'hb; end
+      8'h9a: begin outr <= outr^index[8:5]^4'h6; end
+      8'h9b: begin outr <= outr^index[8:5]^4'h5; end
+      8'h9c: begin outr <= outr^index[8:5]^4'h5; end
+      8'h9d: begin outr <= outr^index[8:5]^4'h4; end
+      8'h9e: begin outr <= outr^index[8:5]^4'h7; end
+      8'h9f: begin outr <= outr^index[8:5]^4'he; end
+      8'ha0: begin outr <= outr^index[8:5]^4'hc; end
+      8'ha1: begin outr <= outr^index[8:5]^4'hc; end
+      8'ha2: begin outr <= outr^index[8:5]^4'h0; end
+      8'ha3: begin outr <= outr^index[8:5]^4'h1; end
+      8'ha4: begin outr <= outr^index[8:5]^4'hd; end
+      8'ha5: begin outr <= outr^index[8:5]^4'h3; end
+      8'ha6: begin outr <= outr^index[8:5]^4'hc; end
+      8'ha7: begin outr <= outr^index[8:5]^4'h2; end
+      8'ha8: begin outr <= outr^index[8:5]^4'h3; end
+      8'ha9: begin outr <= outr^index[8:5]^4'hd; end
+      8'haa: begin outr <= outr^index[8:5]^4'h5; end
+      8'hab: begin outr <= outr^index[8:5]^4'hb; end
+      8'hac: begin outr <= outr^index[8:5]^4'he; end
+      8'had: begin outr <= outr^index[8:5]^4'h0; end
+      8'hae: begin outr <= outr^index[8:5]^4'hf; end
+      8'haf: begin outr <= outr^index[8:5]^4'h9; end
+      8'hb0: begin outr <= outr^index[8:5]^4'hf; end
+      8'hb1: begin outr <= outr^index[8:5]^4'h7; end
+      8'hb2: begin outr <= outr^index[8:5]^4'h9; end
+      8'hb3: begin outr <= outr^index[8:5]^4'hf; end
+      8'hb4: begin outr <= outr^index[8:5]^4'he; end
+      8'hb5: begin outr <= outr^index[8:5]^4'h3; end
+      8'hb6: begin outr <= outr^index[8:5]^4'he; end
+      8'hb7: begin outr <= outr^index[8:5]^4'h8; end
+      8'hb8: begin outr <= outr^index[8:5]^4'hf; end
+      8'hb9: begin outr <= outr^index[8:5]^4'hd; end
+      8'hba: begin outr <= outr^index[8:5]^4'h3; end
+      8'hbb: begin outr <= outr^index[8:5]^4'h5; end
+      8'hbc: begin outr <= outr^index[8:5]^4'hd; end
+      8'hbd: begin outr <= outr^index[8:5]^4'ha; end
+      8'hbe: begin outr <= outr^index[8:5]^4'h7; end
+      8'hbf: begin outr <= outr^index[8:5]^4'he; end
+      8'hc0: begin outr <= outr^index[8:5]^4'h2; end
+      8'hc1: begin outr <= outr^index[8:5]^4'he; end
+      8'hc2: begin outr <= outr^index[8:5]^4'h9; end
+      8'hc3: begin outr <= outr^index[8:5]^4'hb; end
+      8'hc4: begin outr <= outr^index[8:5]^4'h0; end
+      8'hc5: begin outr <= outr^index[8:5]^4'h5; end
+      8'hc6: begin outr <= outr^index[8:5]^4'h9; end
+      8'hc7: begin outr <= outr^index[8:5]^4'h6; end
+      8'hc8: begin outr <= outr^index[8:5]^4'ha; end
+      8'hc9: begin outr <= outr^index[8:5]^4'hf; end
+      8'hca: begin outr <= outr^index[8:5]^4'h3; end
+      8'hcb: begin outr <= outr^index[8:5]^4'hb; end
+      8'hcc: begin outr <= outr^index[8:5]^4'he; end
+      8'hcd: begin outr <= outr^index[8:5]^4'h2; end
+      8'hce: begin outr <= outr^index[8:5]^4'h5; end
+      8'hcf: begin outr <= outr^index[8:5]^4'hf; end
+      8'hd0: begin outr <= outr^index[8:5]^4'h2; end
+      8'hd1: begin outr <= outr^index[8:5]^4'h9; end
+      8'hd2: begin outr <= outr^index[8:5]^4'hb; end
+      8'hd3: begin outr <= outr^index[8:5]^4'h8; end
+      8'hd4: begin outr <= outr^index[8:5]^4'h0; end
+      8'hd5: begin outr <= outr^index[8:5]^4'h2; end
+      8'hd6: begin outr <= outr^index[8:5]^4'hb; end
+      8'hd7: begin outr <= outr^index[8:5]^4'h2; end
+      8'hd8: begin outr <= outr^index[8:5]^4'ha; end
+      8'hd9: begin outr <= outr^index[8:5]^4'hf; end
+      8'hda: begin outr <= outr^index[8:5]^4'h8; end
+      8'hdb: begin outr <= outr^index[8:5]^4'h4; end
+      8'hdc: begin outr <= outr^index[8:5]^4'he; end
+      8'hdd: begin outr <= outr^index[8:5]^4'h6; end
+      8'hde: begin outr <= outr^index[8:5]^4'h9; end
+      8'hdf: begin outr <= outr^index[8:5]^4'h9; end
+      8'he0: begin outr <= outr^index[8:5]^4'h7; end
+      8'he1: begin outr <= outr^index[8:5]^4'h0; end
+      8'he2: begin outr <= outr^index[8:5]^4'h9; end
+      8'he3: begin outr <= outr^index[8:5]^4'h3; end
+      8'he4: begin outr <= outr^index[8:5]^4'h2; end
+      8'he5: begin outr <= outr^index[8:5]^4'h4; end
+      8'he6: begin outr <= outr^index[8:5]^4'h5; end
+      8'he7: begin outr <= outr^index[8:5]^4'h5; end
+      8'he8: begin outr <= outr^index[8:5]^4'hf; end
+      8'he9: begin outr <= outr^index[8:5]^4'ha; end
+      8'hea: begin outr <= outr^index[8:5]^4'hc; end
+      8'heb: begin outr <= outr^index[8:5]^4'hd; end
+      8'hec: begin outr <= outr^index[8:5]^4'h1; end
+      8'hed: begin outr <= outr^index[8:5]^4'h5; end
+      8'hee: begin outr <= outr^index[8:5]^4'h9; end
+      8'hef: begin outr <= outr^index[8:5]^4'h0; end
+      8'hf0: begin outr <= outr^index[8:5]^4'hd; end
+      8'hf1: begin outr <= outr^index[8:5]^4'hf; end
+      8'hf2: begin outr <= outr^index[8:5]^4'h4; end
+      8'hf3: begin outr <= outr^index[8:5]^4'ha; end
+      8'hf4: begin outr <= outr^index[8:5]^4'h8; end
+      8'hf5: begin outr <= outr^index[8:5]^4'he; end
+      8'hf6: begin outr <= outr^index[8:5]^4'he; end
+      8'hf7: begin outr <= outr^index[8:5]^4'h1; end
+      8'hf8: begin outr <= outr^index[8:5]^4'h6; end
+      8'hf9: begin outr <= outr^index[8:5]^4'h0; end
+      8'hfa: begin outr <= outr^index[8:5]^4'h5; end
+      8'hfb: begin outr <= outr^index[8:5]^4'h1; end
+      8'hfc: begin outr <= outr^index[8:5]^4'h8; end
+      8'hfd: begin outr <= outr^index[8:5]^4'h6; end
+      8'hfe: begin outr <= outr^index[8:5]^4'h1; end
+      default: begin outr <= outr^index[8:5]^4'h6; end
+    endcase
+    // verilog_format: on
+  end
 endmodule

test_regress/t/t_case_huge_sub4.v

@@ -7,59 +7,56 @@
 // verilator lint_off LATCH
 
 module t_case_huge_sub4 (/*AUTOARG*/
-   // Outputs
-   outq,
-   // Inputs
-   index
-   );
+  // Outputs
+  outq,
+  // Inputs
+  index
+  );
 
-   input [7:0] index;
-   output [9:0] outq;
+  input [7:0] index;
+  output logic [9:0] outq;
 
-   // =============================
-   /*AUTOREG*/
-   // Beginning of automatic regs (for this module's undeclared outputs)
-   reg [9:0]            outq;
-   // End of automatics
+  // =============================
 
-   // =============================
-   always @(/*AS*/index) begin
-      case (index)
-        // default below: no change
-        8'h00: begin outq = 10'h001; end
-        8'he0: begin outq = 10'h05b; end
-        8'he1: begin outq = 10'h126; end
-        8'he2: begin outq = 10'h369; end
-        8'he3: begin outq = 10'h291; end
-        8'he4: begin outq = 10'h2ca; end
-        8'he5: begin outq = 10'h25b; end
-        8'he6: begin outq = 10'h106; end
-        8'he7: begin outq = 10'h172; end
-        8'he8: begin outq = 10'h2f7; end
-        8'he9: begin outq = 10'h2d3; end
-        8'hea: begin outq = 10'h182; end
-        8'heb: begin outq = 10'h327; end
-        8'hec: begin outq = 10'h1d0; end
-        8'hed: begin outq = 10'h204; end
-        8'hee: begin outq = 10'h11f; end
-        8'hef: begin outq = 10'h365; end
-        8'hf0: begin outq = 10'h2c2; end
-        8'hf1: begin outq = 10'h2b5; end
-        8'hf2: begin outq = 10'h1f8; end
-        8'hf3: begin outq = 10'h2a7; end
-        8'hf4: begin outq = 10'h1be; end
-        8'hf5: begin outq = 10'h25e; end
-        8'hf6: begin outq = 10'h032; end
-        8'hf7: begin outq = 10'h2ef; end
-        8'hf8: begin outq = 10'h02f; end
-        8'hf9: begin outq = 10'h201; end
-        8'hfa: begin outq = 10'h054; end
-        8'hfb: begin outq = 10'h013; end
-        8'hfc: begin outq = 10'h249; end
-        8'hfd: begin outq = 10'h09a; end
-        8'hfe: begin outq = 10'h012; end
-        8'hff: begin outq = 10'h114; end
-        default: ; // No change
-      endcase
-   end
+  always @* begin
+    // verilog_format: off
+    case (index)
+      // default below: no change
+      8'h00: begin outq = 10'h001; end
+      8'he0: begin outq = 10'h05b; end
+      8'he1: begin outq = 10'h126; end
+      8'he2: begin outq = 10'h369; end
+      8'he3: begin outq = 10'h291; end
+      8'he4: begin outq = 10'h2ca; end
+      8'he5: begin outq = 10'h25b; end
+      8'he6: begin outq = 10'h106; end
+      8'he7: begin outq = 10'h172; end
+      8'he8: begin outq = 10'h2f7; end
+      8'he9: begin outq = 10'h2d3; end
+      8'hea: begin outq = 10'h182; end
+      8'heb: begin outq = 10'h327; end
+      8'hec: begin outq = 10'h1d0; end
+      8'hed: begin outq = 10'h204; end
+      8'hee: begin outq = 10'h11f; end
+      8'hef: begin outq = 10'h365; end
+      8'hf0: begin outq = 10'h2c2; end
+      8'hf1: begin outq = 10'h2b5; end
+      8'hf2: begin outq = 10'h1f8; end
+      8'hf3: begin outq = 10'h2a7; end
+      8'hf4: begin outq = 10'h1be; end
+      8'hf5: begin outq = 10'h25e; end
+      8'hf6: begin outq = 10'h032; end
+      8'hf7: begin outq = 10'h2ef; end
+      8'hf8: begin outq = 10'h02f; end
+      8'hf9: begin outq = 10'h201; end
+      8'hfa: begin outq = 10'h054; end
+      8'hfb: begin outq = 10'h013; end
+      8'hfc: begin outq = 10'h249; end
+      8'hfd: begin outq = 10'h09a; end
+      8'hfe: begin outq = 10'h012; end
+      8'hff: begin outq = 10'h114; end
+      default: ; // No change
+    endcase
+    // verilog_format: on
+  end
 endmodule

test_regress/t/t_case_unique_many.v

@@ -4,326 +4,326 @@
 // any use, without warranty, 2024 by Varun Koyyalagunta, Tenstorrent.
 // SPDX-License-Identifier: CC0-1.0
 
-module t (/*AUTOARG*/);
+module t;
 
-    localparam W = 23;
+  localparam W = 23;
 
-    localparam [W-1:0] R0 = W'('h200000 + 0);
-    localparam [W-1:0] R1 = W'('h200000 + 1);
-    localparam [W-1:0] R2 = W'('h200000 + 2);
-    localparam [W-1:0] R3 = W'('h200000 + 3);
-    localparam [W-1:0] R4 = W'('h200000 + 4);
-    localparam [W-1:0] R5 = W'('h200000 + 5);
-    localparam [W-1:0] R6 = W'('h200000 + 6);
-    localparam [W-1:0] R7 = W'('h200000 + 7);
-    localparam [W-1:0] R8 = W'('h200000 + 8);
-    localparam [W-1:0] R9 = W'('h200000 + 9);
-    localparam [W-1:0] R10 = W'('h200000 + 10);
-    localparam [W-1:0] R11 = W'('h200000 + 11);
-    localparam [W-1:0] R12 = W'('h200000 + 12);
-    localparam [W-1:0] R13 = W'('h200000 + 13);
-    localparam [W-1:0] R14 = W'('h200000 + 14);
-    localparam [W-1:0] R15 = W'('h200000 + 15);
-    localparam [W-1:0] R16 = W'('h200000 + 16);
-    localparam [W-1:0] R17 = W'('h200000 + 17);
-    localparam [W-1:0] R18 = W'('h200000 + 18);
-    localparam [W-1:0] R19 = W'('h200000 + 19);
-    localparam [W-1:0] R20 = W'('h200000 + 20);
-    localparam [W-1:0] R21 = W'('h200000 + 21);
-    localparam [W-1:0] R22 = W'('h200000 + 22);
-    localparam [W-1:0] R23 = W'('h200000 + 23);
-    localparam [W-1:0] R24 = W'('h200000 + 24);
-    localparam [W-1:0] R25 = W'('h200000 + 25);
-    localparam [W-1:0] R26 = W'('h200000 + 26);
-    localparam [W-1:0] R27 = W'('h200000 + 27);
-    localparam [W-1:0] R28 = W'('h200000 + 28);
-    localparam [W-1:0] R29 = W'('h200000 + 29);
-    localparam [W-1:0] R30 = W'('h200000 + 30);
-    localparam [W-1:0] R31 = W'('h200000 + 31);
-    localparam [W-1:0] R32 = W'('h200000 + 32);
-    localparam [W-1:0] R33 = W'('h200000 + 33);
-    localparam [W-1:0] R34 = W'('h200000 + 34);
-    localparam [W-1:0] R35 = W'('h200000 + 35);
-    localparam [W-1:0] R36 = W'('h200000 + 36);
-    localparam [W-1:0] R37 = W'('h200000 + 37);
-    localparam [W-1:0] R38 = W'('h200000 + 38);
-    localparam [W-1:0] R39 = W'('h200000 + 39);
-    localparam [W-1:0] R40 = W'('h200000 + 40);
-    localparam [W-1:0] R41 = W'('h200000 + 41);
-    localparam [W-1:0] R42 = W'('h200000 + 42);
-    localparam [W-1:0] R43 = W'('h200000 + 43);
-    localparam [W-1:0] R44 = W'('h200000 + 44);
-    localparam [W-1:0] R45 = W'('h200000 + 45);
-    localparam [W-1:0] R46 = W'('h200000 + 46);
-    localparam [W-1:0] R47 = W'('h200000 + 47);
-    localparam [W-1:0] R48 = W'('h200000 + 48);
-    localparam [W-1:0] R49 = W'('h200000 + 49);
-    localparam [W-1:0] R50 = W'('h200000 + 50);
-    localparam [W-1:0] R51 = W'('h200000 + 51);
-    localparam [W-1:0] R52 = W'('h200000 + 52);
-    localparam [W-1:0] R53 = W'('h200000 + 53);
-    localparam [W-1:0] R54 = W'('h200000 + 54);
-    localparam [W-1:0] R55 = W'('h200000 + 55);
-    localparam [W-1:0] R56 = W'('h200000 + 56);
-    localparam [W-1:0] R57 = W'('h200000 + 57);
-    localparam [W-1:0] R58 = W'('h200000 + 58);
-    localparam [W-1:0] R59 = W'('h200000 + 59);
-    localparam [W-1:0] R60 = W'('h200000 + 60);
-    localparam [W-1:0] R61 = W'('h200000 + 61);
-    localparam [W-1:0] R62 = W'('h200000 + 62);
-    localparam [W-1:0] R63 = W'('h200000 + 63);
-    localparam [W-1:0] R64 = W'('h200000 + 64);
-    localparam [W-1:0] R65 = W'('h200000 + 65);
-    localparam [W-1:0] R66 = W'('h200000 + 66);
-    localparam [W-1:0] R67 = W'('h200000 + 67);
-    localparam [W-1:0] R68 = W'('h200000 + 68);
-    localparam [W-1:0] R69 = W'('h200000 + 69);
-    localparam [W-1:0] R70 = W'('h200000 + 70);
-    localparam [W-1:0] R71 = W'('h200000 + 71);
-    localparam [W-1:0] R72 = W'('h200000 + 72);
-    localparam [W-1:0] R73 = W'('h200000 + 73);
-    localparam [W-1:0] R74 = W'('h200000 + 74);
-    localparam [W-1:0] R75 = W'('h200000 + 75);
-    localparam [W-1:0] R76 = W'('h200000 + 76);
-    localparam [W-1:0] R77 = W'('h200000 + 77);
-    localparam [W-1:0] R78 = W'('h200000 + 78);
-    localparam [W-1:0] R79 = W'('h200000 + 79);
-    localparam [W-1:0] R80 = W'('h200000 + 80);
-    localparam [W-1:0] R81 = W'('h200000 + 81);
-    localparam [W-1:0] R82 = W'('h200000 + 82);
-    localparam [W-1:0] R83 = W'('h200000 + 83);
-    localparam [W-1:0] R84 = W'('h200000 + 84);
-    localparam [W-1:0] R85 = W'('h200000 + 85);
-    localparam [W-1:0] R86 = W'('h200000 + 86);
-    localparam [W-1:0] R87 = W'('h200000 + 87);
-    localparam [W-1:0] R88 = W'('h200000 + 88);
-    localparam [W-1:0] R89 = W'('h200000 + 89);
-    localparam [W-1:0] R90 = W'('h200000 + 90);
-    localparam [W-1:0] R91 = W'('h200000 + 91);
-    localparam [W-1:0] R92 = W'('h200000 + 92);
-    localparam [W-1:0] R93 = W'('h200000 + 93);
-    localparam [W-1:0] R94 = W'('h200000 + 94);
-    localparam [W-1:0] R95 = W'('h200000 + 95);
-    localparam [W-1:0] R96 = W'('h200000 + 96);
-    localparam [W-1:0] R97 = W'('h200000 + 97);
-    localparam [W-1:0] R98 = W'('h200000 + 98);
-    localparam [W-1:0] R99 = W'('h200000 + 99);
-    typedef struct packed {
-        logic  r0;
-        logic  r1;
-        logic  r2;
-        logic  r3;
-        logic  r4;
-        logic  r5;
-        logic  r6;
-        logic  r7;
-        logic  r8;
-        logic  r9;
-        logic  r10;
-        logic  r11;
-        logic  r12;
-        logic  r13;
-        logic  r14;
-        logic  r15;
-        logic  r16;
-        logic  r17;
-        logic  r18;
-        logic  r19;
-        logic  r20;
-        logic  r21;
-        logic  r22;
-        logic  r23;
-        logic  r24;
-        logic  r25;
-        logic  r26;
-        logic  r27;
-        logic  r28;
-        logic  r29;
-        logic  r30;
-        logic  r31;
-        logic  r32;
-        logic  r33;
-        logic  r34;
-        logic  r35;
-        logic  r36;
-        logic  r37;
-        logic  r38;
-        logic  r39;
-        logic  r40;
-        logic  r41;
-        logic  r42;
-        logic  r43;
-        logic  r44;
-        logic  r45;
-        logic  r46;
-        logic  r47;
-        logic  r48;
-        logic  r49;
-        logic  r50;
-        logic  r51;
-        logic  r52;
-        logic  r53;
-        logic  r54;
-        logic  r55;
-        logic  r56;
-        logic  r57;
-        logic  r58;
-        logic  r59;
-        logic  r60;
-        logic  r61;
-        logic  r62;
-        logic  r63;
-        logic  r64;
-        logic  r65;
-        logic  r66;
-        logic  r67;
-        logic  r68;
-        logic  r69;
-        logic  r70;
-        logic  r71;
-        logic  r72;
-        logic  r73;
-        logic  r74;
-        logic  r75;
-        logic  r76;
-        logic  r77;
-        logic  r78;
-        logic  r79;
-        logic  r80;
-        logic  r81;
-        logic  r82;
-        logic  r83;
-        logic  r84;
-        logic  r85;
-        logic  r86;
-        logic  r87;
-        logic  r88;
-        logic  r89;
-        logic  r90;
-        logic  r91;
-        logic  r92;
-        logic  r93;
-        logic  r94;
-        logic  r95;
-        logic  r96;
-        logic  r97;
-        logic  r98;
-        logic  r99;
-    } hit_t;
-    function automatic hit_t get_hit(input logic [22:0] a);
-        hit_t hit = '0;
-        unique case (a)
-            R0 : begin hit.r0 = 1'b1; end
-            R1 : begin hit.r1 = 1'b1; end
-            R2 : begin hit.r2 = 1'b1; end
-            R3 : begin hit.r3 = 1'b1; end
-            R4 : begin hit.r4 = 1'b1; end
-            R5 : begin hit.r5 = 1'b1; end
-            R6 : begin hit.r6 = 1'b1; end
-            R7 : begin hit.r7 = 1'b1; end
-            R8 : begin hit.r8 = 1'b1; end
-            R9 : begin hit.r9 = 1'b1; end
-            R10 : begin hit.r10 = 1'b1; end
-            R11 : begin hit.r11 = 1'b1; end
-            R12 : begin hit.r12 = 1'b1; end
-            R13 : begin hit.r13 = 1'b1; end
-            R14 : begin hit.r14 = 1'b1; end
-            R15 : begin hit.r15 = 1'b1; end
-            R16 : begin hit.r16 = 1'b1; end
-            R17 : begin hit.r17 = 1'b1; end
-            R18 : begin hit.r18 = 1'b1; end
-            R19 : begin hit.r19 = 1'b1; end
-            R20 : begin hit.r20 = 1'b1; end
-            R21 : begin hit.r21 = 1'b1; end
-            R22 : begin hit.r22 = 1'b1; end
-            R23 : begin hit.r23 = 1'b1; end
-            R24 : begin hit.r24 = 1'b1; end
-            R25 : begin hit.r25 = 1'b1; end
-            R26 : begin hit.r26 = 1'b1; end
-            R27 : begin hit.r27 = 1'b1; end
-            R28 : begin hit.r28 = 1'b1; end
-            R29 : begin hit.r29 = 1'b1; end
-            R30 : begin hit.r30 = 1'b1; end
-            R31 : begin hit.r31 = 1'b1; end
-            R32 : begin hit.r32 = 1'b1; end
-            R33 : begin hit.r33 = 1'b1; end
-            R34 : begin hit.r34 = 1'b1; end
-            R35 : begin hit.r35 = 1'b1; end
-            R36 : begin hit.r36 = 1'b1; end
-            R37 : begin hit.r37 = 1'b1; end
-            R38 : begin hit.r38 = 1'b1; end
-            R39 : begin hit.r39 = 1'b1; end
-            R40 : begin hit.r40 = 1'b1; end
-            R41 : begin hit.r41 = 1'b1; end
-            R42 : begin hit.r42 = 1'b1; end
-            R43 : begin hit.r43 = 1'b1; end
-            R44 : begin hit.r44 = 1'b1; end
-            R45 : begin hit.r45 = 1'b1; end
-            R46 : begin hit.r46 = 1'b1; end
-            R47 : begin hit.r47 = 1'b1; end
-            R48 : begin hit.r48 = 1'b1; end
-            R49 : begin hit.r49 = 1'b1; end
-            R50 : begin hit.r50 = 1'b1; end
-            R51 : begin hit.r51 = 1'b1; end
-            R52 : begin hit.r52 = 1'b1; end
-            R53 : begin hit.r53 = 1'b1; end
-            R54 : begin hit.r54 = 1'b1; end
-            R55 : begin hit.r55 = 1'b1; end
-            R56 : begin hit.r56 = 1'b1; end
-            R57 : begin hit.r57 = 1'b1; end
-            R58 : begin hit.r58 = 1'b1; end
-            R59 : begin hit.r59 = 1'b1; end
-            R60 : begin hit.r60 = 1'b1; end
-            R61 : begin hit.r61 = 1'b1; end
-            R62 : begin hit.r62 = 1'b1; end
-            R63 : begin hit.r63 = 1'b1; end
-            R64 : begin hit.r64 = 1'b1; end
-            R65 : begin hit.r65 = 1'b1; end
-            R66 : begin hit.r66 = 1'b1; end
-            R67 : begin hit.r67 = 1'b1; end
-            R68 : begin hit.r68 = 1'b1; end
-            R69 : begin hit.r69 = 1'b1; end
-            R70 : begin hit.r70 = 1'b1; end
-            R71 : begin hit.r71 = 1'b1; end
-            R72 : begin hit.r72 = 1'b1; end
-            R73 : begin hit.r73 = 1'b1; end
-            R74 : begin hit.r74 = 1'b1; end
-            R75 : begin hit.r75 = 1'b1; end
-            R76 : begin hit.r76 = 1'b1; end
-            R77 : begin hit.r77 = 1'b1; end
-            R78 : begin hit.r78 = 1'b1; end
-            R79 : begin hit.r79 = 1'b1; end
-            R80 : begin hit.r80 = 1'b1; end
-            R81 : begin hit.r81 = 1'b1; end
-            R82 : begin hit.r82 = 1'b1; end
-            R83 : begin hit.r83 = 1'b1; end
-            R84 : begin hit.r84 = 1'b1; end
-            R85 : begin hit.r85 = 1'b1; end
-            R86 : begin hit.r86 = 1'b1; end
-            R87 : begin hit.r87 = 1'b1; end
-            R88 : begin hit.r88 = 1'b1; end
-            R89 : begin hit.r89 = 1'b1; end
-            R90 : begin hit.r90 = 1'b1; end
-            R91 : begin hit.r91 = 1'b1; end
-            R92 : begin hit.r92 = 1'b1; end
-            R93 : begin hit.r93 = 1'b1; end
-            R94 : begin hit.r94 = 1'b1; end
-            R95 : begin hit.r95 = 1'b1; end
-            R96 : begin hit.r96 = 1'b1; end
-            R97 : begin hit.r97 = 1'b1; end
-            R98 : begin hit.r98 = 1'b1; end
-            R99 : begin hit.r99 = 1'b1; end
-           default: begin hit = '0; end
-       endcase
-       return hit;
-    endfunction
+  localparam [W-1:0] R0 = W'('h200000 + 0);
+  localparam [W-1:0] R1 = W'('h200000 + 1);
+  localparam [W-1:0] R2 = W'('h200000 + 2);
+  localparam [W-1:0] R3 = W'('h200000 + 3);
+  localparam [W-1:0] R4 = W'('h200000 + 4);
+  localparam [W-1:0] R5 = W'('h200000 + 5);
+  localparam [W-1:0] R6 = W'('h200000 + 6);
+  localparam [W-1:0] R7 = W'('h200000 + 7);
+  localparam [W-1:0] R8 = W'('h200000 + 8);
+  localparam [W-1:0] R9 = W'('h200000 + 9);
+  localparam [W-1:0] R10 = W'('h200000 + 10);
+  localparam [W-1:0] R11 = W'('h200000 + 11);
+  localparam [W-1:0] R12 = W'('h200000 + 12);
+  localparam [W-1:0] R13 = W'('h200000 + 13);
+  localparam [W-1:0] R14 = W'('h200000 + 14);
+  localparam [W-1:0] R15 = W'('h200000 + 15);
+  localparam [W-1:0] R16 = W'('h200000 + 16);
+  localparam [W-1:0] R17 = W'('h200000 + 17);
+  localparam [W-1:0] R18 = W'('h200000 + 18);
+  localparam [W-1:0] R19 = W'('h200000 + 19);
+  localparam [W-1:0] R20 = W'('h200000 + 20);
+  localparam [W-1:0] R21 = W'('h200000 + 21);
+  localparam [W-1:0] R22 = W'('h200000 + 22);
+  localparam [W-1:0] R23 = W'('h200000 + 23);
+  localparam [W-1:0] R24 = W'('h200000 + 24);
+  localparam [W-1:0] R25 = W'('h200000 + 25);
+  localparam [W-1:0] R26 = W'('h200000 + 26);
+  localparam [W-1:0] R27 = W'('h200000 + 27);
+  localparam [W-1:0] R28 = W'('h200000 + 28);
+  localparam [W-1:0] R29 = W'('h200000 + 29);
+  localparam [W-1:0] R30 = W'('h200000 + 30);
+  localparam [W-1:0] R31 = W'('h200000 + 31);
+  localparam [W-1:0] R32 = W'('h200000 + 32);
+  localparam [W-1:0] R33 = W'('h200000 + 33);
+  localparam [W-1:0] R34 = W'('h200000 + 34);
+  localparam [W-1:0] R35 = W'('h200000 + 35);
+  localparam [W-1:0] R36 = W'('h200000 + 36);
+  localparam [W-1:0] R37 = W'('h200000 + 37);
+  localparam [W-1:0] R38 = W'('h200000 + 38);
+  localparam [W-1:0] R39 = W'('h200000 + 39);
+  localparam [W-1:0] R40 = W'('h200000 + 40);
+  localparam [W-1:0] R41 = W'('h200000 + 41);
+  localparam [W-1:0] R42 = W'('h200000 + 42);
+  localparam [W-1:0] R43 = W'('h200000 + 43);
+  localparam [W-1:0] R44 = W'('h200000 + 44);
+  localparam [W-1:0] R45 = W'('h200000 + 45);
+  localparam [W-1:0] R46 = W'('h200000 + 46);
+  localparam [W-1:0] R47 = W'('h200000 + 47);
+  localparam [W-1:0] R48 = W'('h200000 + 48);
+  localparam [W-1:0] R49 = W'('h200000 + 49);
+  localparam [W-1:0] R50 = W'('h200000 + 50);
+  localparam [W-1:0] R51 = W'('h200000 + 51);
+  localparam [W-1:0] R52 = W'('h200000 + 52);
+  localparam [W-1:0] R53 = W'('h200000 + 53);
+  localparam [W-1:0] R54 = W'('h200000 + 54);
+  localparam [W-1:0] R55 = W'('h200000 + 55);
+  localparam [W-1:0] R56 = W'('h200000 + 56);
+  localparam [W-1:0] R57 = W'('h200000 + 57);
+  localparam [W-1:0] R58 = W'('h200000 + 58);
+  localparam [W-1:0] R59 = W'('h200000 + 59);
+  localparam [W-1:0] R60 = W'('h200000 + 60);
+  localparam [W-1:0] R61 = W'('h200000 + 61);
+  localparam [W-1:0] R62 = W'('h200000 + 62);
+  localparam [W-1:0] R63 = W'('h200000 + 63);
+  localparam [W-1:0] R64 = W'('h200000 + 64);
+  localparam [W-1:0] R65 = W'('h200000 + 65);
+  localparam [W-1:0] R66 = W'('h200000 + 66);
+  localparam [W-1:0] R67 = W'('h200000 + 67);
+  localparam [W-1:0] R68 = W'('h200000 + 68);
+  localparam [W-1:0] R69 = W'('h200000 + 69);
+  localparam [W-1:0] R70 = W'('h200000 + 70);
+  localparam [W-1:0] R71 = W'('h200000 + 71);
+  localparam [W-1:0] R72 = W'('h200000 + 72);
+  localparam [W-1:0] R73 = W'('h200000 + 73);
+  localparam [W-1:0] R74 = W'('h200000 + 74);
+  localparam [W-1:0] R75 = W'('h200000 + 75);
+  localparam [W-1:0] R76 = W'('h200000 + 76);
+  localparam [W-1:0] R77 = W'('h200000 + 77);
+  localparam [W-1:0] R78 = W'('h200000 + 78);
+  localparam [W-1:0] R79 = W'('h200000 + 79);
+  localparam [W-1:0] R80 = W'('h200000 + 80);
+  localparam [W-1:0] R81 = W'('h200000 + 81);
+  localparam [W-1:0] R82 = W'('h200000 + 82);
+  localparam [W-1:0] R83 = W'('h200000 + 83);
+  localparam [W-1:0] R84 = W'('h200000 + 84);
+  localparam [W-1:0] R85 = W'('h200000 + 85);
+  localparam [W-1:0] R86 = W'('h200000 + 86);
+  localparam [W-1:0] R87 = W'('h200000 + 87);
+  localparam [W-1:0] R88 = W'('h200000 + 88);
+  localparam [W-1:0] R89 = W'('h200000 + 89);
+  localparam [W-1:0] R90 = W'('h200000 + 90);
+  localparam [W-1:0] R91 = W'('h200000 + 91);
+  localparam [W-1:0] R92 = W'('h200000 + 92);
+  localparam [W-1:0] R93 = W'('h200000 + 93);
+  localparam [W-1:0] R94 = W'('h200000 + 94);
+  localparam [W-1:0] R95 = W'('h200000 + 95);
+  localparam [W-1:0] R96 = W'('h200000 + 96);
+  localparam [W-1:0] R97 = W'('h200000 + 97);
+  localparam [W-1:0] R98 = W'('h200000 + 98);
+  localparam [W-1:0] R99 = W'('h200000 + 99);
+  typedef struct packed {
+    logic r0;
+    logic r1;
+    logic r2;
+    logic r3;
+    logic r4;
+    logic r5;
+    logic r6;
+    logic r7;
+    logic r8;
+    logic r9;
+    logic r10;
+    logic r11;
+    logic r12;
+    logic r13;
+    logic r14;
+    logic r15;
+    logic r16;
+    logic r17;
+    logic r18;
+    logic r19;
+    logic r20;
+    logic r21;
+    logic r22;
+    logic r23;
+    logic r24;
+    logic r25;
+    logic r26;
+    logic r27;
+    logic r28;
+    logic r29;
+    logic r30;
+    logic r31;
+    logic r32;
+    logic r33;
+    logic r34;
+    logic r35;
+    logic r36;
+    logic r37;
+    logic r38;
+    logic r39;
+    logic r40;
+    logic r41;
+    logic r42;
+    logic r43;
+    logic r44;
+    logic r45;
+    logic r46;
+    logic r47;
+    logic r48;
+    logic r49;
+    logic r50;
+    logic r51;
+    logic r52;
+    logic r53;
+    logic r54;
+    logic r55;
+    logic r56;
+    logic r57;
+    logic r58;
+    logic r59;
+    logic r60;
+    logic r61;
+    logic r62;
+    logic r63;
+    logic r64;
+    logic r65;
+    logic r66;
+    logic r67;
+    logic r68;
+    logic r69;
+    logic r70;
+    logic r71;
+    logic r72;
+    logic r73;
+    logic r74;
+    logic r75;
+    logic r76;
+    logic r77;
+    logic r78;
+    logic r79;
+    logic r80;
+    logic r81;
+    logic r82;
+    logic r83;
+    logic r84;
+    logic r85;
+    logic r86;
+    logic r87;
+    logic r88;
+    logic r89;
+    logic r90;
+    logic r91;
+    logic r92;
+    logic r93;
+    logic r94;
+    logic r95;
+    logic r96;
+    logic r97;
+    logic r98;
+    logic r99;
+  } hit_t;
+  function automatic hit_t get_hit(input logic [22:0] a);
+    hit_t hit = '0;
+    unique case (a)
+      R0: hit.r0 = 1'b1;
+      R1: hit.r1 = 1'b1;
+      R2: hit.r2 = 1'b1;
+      R3: hit.r3 = 1'b1;
+      R4: hit.r4 = 1'b1;
+      R5: hit.r5 = 1'b1;
+      R6: hit.r6 = 1'b1;
+      R7: hit.r7 = 1'b1;
+      R8: hit.r8 = 1'b1;
+      R9: hit.r9 = 1'b1;
+      R10: hit.r10 = 1'b1;
+      R11: hit.r11 = 1'b1;
+      R12: hit.r12 = 1'b1;
+      R13: hit.r13 = 1'b1;
+      R14: hit.r14 = 1'b1;
+      R15: hit.r15 = 1'b1;
+      R16: hit.r16 = 1'b1;
+      R17: hit.r17 = 1'b1;
+      R18: hit.r18 = 1'b1;
+      R19: hit.r19 = 1'b1;
+      R20: hit.r20 = 1'b1;
+      R21: hit.r21 = 1'b1;
+      R22: hit.r22 = 1'b1;
+      R23: hit.r23 = 1'b1;
+      R24: hit.r24 = 1'b1;
+      R25: hit.r25 = 1'b1;
+      R26: hit.r26 = 1'b1;
+      R27: hit.r27 = 1'b1;
+      R28: hit.r28 = 1'b1;
+      R29: hit.r29 = 1'b1;
+      R30: hit.r30 = 1'b1;
+      R31: hit.r31 = 1'b1;
+      R32: hit.r32 = 1'b1;
+      R33: hit.r33 = 1'b1;
+      R34: hit.r34 = 1'b1;
+      R35: hit.r35 = 1'b1;
+      R36: hit.r36 = 1'b1;
+      R37: hit.r37 = 1'b1;
+      R38: hit.r38 = 1'b1;
+      R39: hit.r39 = 1'b1;
+      R40: hit.r40 = 1'b1;
+      R41: hit.r41 = 1'b1;
+      R42: hit.r42 = 1'b1;
+      R43: hit.r43 = 1'b1;
+      R44: hit.r44 = 1'b1;
+      R45: hit.r45 = 1'b1;
+      R46: hit.r46 = 1'b1;
+      R47: hit.r47 = 1'b1;
+      R48: hit.r48 = 1'b1;
+      R49: hit.r49 = 1'b1;
+      R50: hit.r50 = 1'b1;
+      R51: hit.r51 = 1'b1;
+      R52: hit.r52 = 1'b1;
+      R53: hit.r53 = 1'b1;
+      R54: hit.r54 = 1'b1;
+      R55: hit.r55 = 1'b1;
+      R56: hit.r56 = 1'b1;
+      R57: hit.r57 = 1'b1;
+      R58: hit.r58 = 1'b1;
+      R59: hit.r59 = 1'b1;
+      R60: hit.r60 = 1'b1;
+      R61: hit.r61 = 1'b1;
+      R62: hit.r62 = 1'b1;
+      R63: hit.r63 = 1'b1;
+      R64: hit.r64 = 1'b1;
+      R65: hit.r65 = 1'b1;
+      R66: hit.r66 = 1'b1;
+      R67: hit.r67 = 1'b1;
+      R68: hit.r68 = 1'b1;
+      R69: hit.r69 = 1'b1;
+      R70: hit.r70 = 1'b1;
+      R71: hit.r71 = 1'b1;
+      R72: hit.r72 = 1'b1;
+      R73: hit.r73 = 1'b1;
+      R74: hit.r74 = 1'b1;
+      R75: hit.r75 = 1'b1;
+      R76: hit.r76 = 1'b1;
+      R77: hit.r77 = 1'b1;
+      R78: hit.r78 = 1'b1;
+      R79: hit.r79 = 1'b1;
+      R80: hit.r80 = 1'b1;
+      R81: hit.r81 = 1'b1;
+      R82: hit.r82 = 1'b1;
+      R83: hit.r83 = 1'b1;
+      R84: hit.r84 = 1'b1;
+      R85: hit.r85 = 1'b1;
+      R86: hit.r86 = 1'b1;
+      R87: hit.r87 = 1'b1;
+      R88: hit.r88 = 1'b1;
+      R89: hit.r89 = 1'b1;
+      R90: hit.r90 = 1'b1;
+      R91: hit.r91 = 1'b1;
+      R92: hit.r92 = 1'b1;
+      R93: hit.r93 = 1'b1;
+      R94: hit.r94 = 1'b1;
+      R95: hit.r95 = 1'b1;
+      R96: hit.r96 = 1'b1;
+      R97: hit.r97 = 1'b1;
+      R98: hit.r98 = 1'b1;
+      R99: hit.r99 = 1'b1;
+      default: hit = '0;
+    endcase
+    return hit;
+  endfunction
 
-   initial begin
-      if (get_hit(R30) !== hit_t'{r30: 1'b1, default: '0}) $stop;
-      if (get_hit('1) !== '0) $stop;
-      if (get_hit('0) !== '0) $stop;
-      $write("*-* All Finished *-*\n");
-      $finish;
-   end
+  initial begin
+    if (get_hit(R30) !== hit_t'{r30: 1'b1, default: '0}) $stop;
+    if (get_hit('1) !== '0) $stop;
+    if (get_hit('0) !== '0) $stop;
+    $write("*-* All Finished *-*\n");
+    $finish;
+  end
 
 endmodule

test_regress/t/t_class_hier_construction.py

@@ -0,0 +1,18 @@
+#!/usr/bin/env python3
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2025 by Wilson Snyder. This program is free software; you
+# can redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+# SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
+
+import vltest_bootstrap
+
+test.scenarios('simulator')
+
+test.compile()
+
+test.execute()
+
+test.passes()

test_regress/t/t_class_hier_construction.v

@@ -0,0 +1,88 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2025 by Petr Nohavica
+// SPDX-License-Identifier: CC0-1.0
+
+`define stop $stop
+`define checkh(gotv,expv) do if ((gotv) !== (expv)) begin $write("%%Error: %s:%0d:  got='h%x exp='h%x\n", `__FILE__,`__LINE__, (gotv), (expv)); `stop; end while(0);
+`define checks(gotv,expv) do if ((gotv) != (expv)) begin $write("%%Error: %s:%0d:  got='%s' exp='%s'\n", `__FILE__,`__LINE__, (gotv), (expv)); `stop; end while(0);
+
+interface class IBottomMid;
+    pure virtual function void moo(int i);
+endclass
+
+interface class IBottom;
+   pure virtual function bit foo();
+endclass
+
+interface class IMid extends IBottomMid;
+   pure virtual function string bar();
+endclass
+
+class bottom_class implements IBottom;
+    string name;
+
+    function new(string name);
+        this.name = name;
+    endfunction
+
+    virtual function bit foo();
+        $display("%s", name);
+    endfunction
+endclass
+
+class middle_class extends bottom_class implements IMid, IBottom;
+    function new(string name);
+        super.new($sformatf("middle %0s", name));
+    endfunction
+
+    virtual function bit foo();
+        $display("%s", name);
+        return 0;
+   endfunction
+
+    virtual function void moo(int i);
+        $display("moo: %d", i);
+    endfunction
+
+   virtual function string bar();
+        return name;
+   endfunction
+endclass
+
+class top_class extends middle_class;
+    int i;
+    function new(string name, int i);
+        super.new($sformatf("%0s %0d", name, i));
+        this.i = i;
+    endfunction
+endclass
+
+class sky_class extends top_class;
+    function new(string name);
+        super.new(name, 42);
+    endfunction
+endclass
+
+
+module t;
+
+    initial begin
+        sky_class s = new("ahoj");
+        bottom_class b = s;
+        top_class t = s;
+        IMid im;
+
+        `checks( b.name, "middle ahoj 42" );
+        `checks( s.name, "middle ahoj 42" );
+        `checks( t.name, "middle ahoj 42" );
+        `checkh( t.i, 42);
+        `checks(s.bar(), "middle ahoj 42");
+        im = s;
+        im.moo(42);
+
+        $finish;
+    end
+
+endmodule

test_regress/t/t_class_param_subtype2.py

@@ -0,0 +1,18 @@
+#!/usr/bin/env python3
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2025 by Wilson Snyder. This program is free software; you
+# can redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+# SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
+
+import vltest_bootstrap
+
+test.scenarios('simulator')
+
+test.compile()
+
+test.execute()
+
+test.passes()

test_regress/t/t_class_param_subtype2.v

@@ -0,0 +1,26 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2025 by Antmicro.
+// SPDX-License-Identifier: CC0-1.0
+
+class Class1 #(type T);
+   static function int get();
+      return T::Helper::getter();
+   endfunction
+endclass
+
+class Class2;
+   typedef Class2 Helper;
+   static function int getter();
+      return 13;
+   endfunction
+endclass
+
+module t;
+   initial begin
+      if (Class1#(Class2)::get() != 13) $stop;
+      $write("*-* All Finished *-*\n");
+      $finish;
+   end
+endmodule

test_regress/t/t_class_reference_name_colision.py

@@ -0,0 +1,16 @@
+#!/usr/bin/env python3
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2025 by Wilson Snyder. This program is free software; you
+# can redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+# SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
+
+import vltest_bootstrap
+
+test.scenarios('simulator')
+
+test.compile()
+
+test.passes()

test_regress/t/t_class_reference_name_colision.v

@@ -0,0 +1,17 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2025 by Antmicro.
+// SPDX-License-Identifier: CC0-1.0
+
+class setup_coefficients;
+    static function int create();
+        return 1;
+    endfunction
+endclass
+
+class biquad_vseq;
+    int c_setup = setup_coefficients::create();
+    function void setup_coefficients();
+    endfunction
+endclass: biquad_vseq

test_regress/t/t_cover_expr_array_class.py

@@ -0,0 +1,18 @@
+#!/usr/bin/env python3
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2025 by Wilson Snyder. This program is free software; you
+# can redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+# SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
+
+import vltest_bootstrap
+
+test.scenarios('simulator')
+
+test.compile(verilator_flags2=['--coverage-expr'])
+
+test.execute()
+
+test.passes()

test_regress/t/t_cover_expr_array_class.v

@@ -0,0 +1,26 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2025 by Antmicro.
+// SPDX-License-Identifier: CC0-1.0
+
+class Class1;
+   int value0 = 7;
+endclass
+
+module t;
+   initial begin
+      int i = 0;
+      Class1 q[15];
+      for (int j = 0; j < 15; j = j + 1) begin
+         Class1 x = new;
+         q[j] = x;
+      end
+      while (i < 15) begin
+         if ((q[i].value0 > 8) || (q[i].value0 < 5)) $stop;
+         i += 1;
+      end
+      $write("*-* All Finished *-*\n");
+      $finish;
+   end
+endmodule

test_regress/t/t_cover_expr_associative_array_class.py

@@ -0,0 +1,18 @@
+#!/usr/bin/env python3
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2025 by Wilson Snyder. This program is free software; you
+# can redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+# SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
+
+import vltest_bootstrap
+
+test.scenarios('simulator')
+
+test.compile(verilator_flags2=['--coverage-expr'])
+
+test.execute()
+
+test.passes()

test_regress/t/t_cover_expr_associative_array_class.v

@@ -0,0 +1,26 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2025 by Antmicro.
+// SPDX-License-Identifier: CC0-1.0
+
+class Class1;
+  int value0 = 7;
+endclass
+
+module t;
+  initial begin
+    int i = 0;
+    Class1 q[int] = '{};
+    for (int j = 0; j < 15; j = j + 1) begin
+      Class1 x = new;
+      q[j] = x;
+    end
+    while (i < 15) begin
+      if ((q[i].value0 > 8) || (q[i].value0 < 5)) $stop;
+      i += 1;
+    end
+    $write("*-* All Finished *-*\n");
+    $finish;
+  end
+endmodule

test_regress/t/t_cover_expr_dyn_array_class.py

@@ -0,0 +1,18 @@
+#!/usr/bin/env python3
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2025 by Wilson Snyder. This program is free software; you
+# can redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+# SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
+
+import vltest_bootstrap
+
+test.scenarios('simulator')
+
+test.compile(verilator_flags2=['--coverage-expr'])
+
+test.execute()
+
+test.passes()

test_regress/t/t_cover_expr_dyn_array_class.v

@@ -0,0 +1,26 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2025 by Antmicro.
+// SPDX-License-Identifier: CC0-1.0
+
+class Class1;
+   int value0 = 7;
+endclass
+
+module t;
+   initial begin
+      int i = 0;
+      Class1 q[] = new [15];
+      for (int j = 0; j < 15; j = j + 1) begin
+         Class1 x = new;
+         q[j] = x;
+      end
+      while (i < 15) begin
+         if ((q[i].value0 > 8) || (q[i].value0 < 5)) $stop;
+         i += 1;
+      end
+      $write("*-* All Finished *-*\n");
+      $finish;
+   end
+endmodule

test_regress/t/t_cover_expr_queue_class.py

@@ -0,0 +1,18 @@
+#!/usr/bin/env python3
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2025 by Wilson Snyder. This program is free software; you
+# can redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+# SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
+
+import vltest_bootstrap
+
+test.scenarios('simulator')
+
+test.compile(verilator_flags2=['--coverage-expr'])
+
+test.execute()
+
+test.passes()

test_regress/t/t_cover_expr_queue_class.v

@@ -0,0 +1,26 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2025 by Antmicro.
+// SPDX-License-Identifier: CC0-1.0
+
+class Class1;
+   int value0 = 7;
+endclass
+
+module t;
+   initial begin
+      int i = 0;
+      Class1 q[$];
+      repeat(15) begin
+         Class1 x = new;
+         q = { q, x };
+      end
+      while (i < q.size()) begin
+         if ((q[i].value0 > 8) || (q[i].value0 < 5)) $stop;
+         i += 1;
+      end
+      $write("*-* All Finished *-*\n");
+      $finish;
+   end
+endmodule

test_regress/t/t_cover_toggle_init.py

@@ -0,0 +1,20 @@
+#!/usr/bin/env python3
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2025 by Wilson Snyder. This program is free software; you
+# can redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+# SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
+
+import vltest_bootstrap
+
+test.scenarios('simulator')
+
+test.compile(verilator_flags2=['--cc --coverage-toggle --stats'])
+
+test.execute()
+
+test.inline_checks()
+
+test.passes()

test_regress/t/t_cover_toggle_init.v

@@ -0,0 +1,63 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2025 by Antmicro.
+// SPDX-License-Identifier: CC0-1.0
+
+module t(clk);
+   // verilator coverage_off
+   input clk;
+   integer cyc;
+   // verilator coverage_on
+
+   logic logic_unused;
+   // CHECK_COVER(-1,"top.t","logic_unused",0)
+
+   bit bit_unused;
+   // CHECK_COVER(-1,"top.t","bit_unused",0)
+
+   logic logic_always_0;
+   // CHECK_COVER(-1,"top.t","logic_always_0",0)
+
+   bit bit_always_0;
+   // CHECK_COVER(-1,"top.t","bit_always_0",0)
+
+   logic logic_always_1;
+   // CHECK_COVER(-1,"top.t","logic_always_1",0)
+
+   bit bit_always_1;
+   // CHECK_COVER(-1,"top.t","bit_always_1",1)
+
+   logic logic_initial_0;
+   // CHECK_COVER(-1,"top.t","logic_initial_0",0)
+
+   bit bit_initial_0;
+   // CHECK_COVER(-1,"top.t","bit_initial_0",0)
+
+   logic logic_initial_1;
+   // CHECK_COVER(-1,"top.t","logic_initial_1",0)
+
+   bit bit_initial_1;
+   // CHECK_COVER(-1,"top.t","bit_initial_1",1)
+
+   initial begin
+      cyc = 1;
+      logic_initial_0 = 0;
+      bit_initial_0 = 0;
+      logic_initial_1 = 1;
+      bit_initial_1 = 1;
+   end
+
+   always @(posedge clk) begin
+      logic_always_0 = 0;
+      bit_always_0 = 0;
+      logic_always_1 = 1;
+      bit_always_1 = 1;
+
+      if (cyc != 0) cyc <= cyc + 1;
+      if (cyc == 10) begin
+         $write("*-* All Finished *-*\n");
+         $finish;
+      end
+   end
+endmodule

test_regress/t/t_cover_unused_bad.out

@@ -1,7 +1,7 @@
-%Warning-UNUSEDSIGNAL: t/t_cover_unused_bad.v:14:10: Signal is not used: 'unu3'
-                                                   : ... note: In instance 't'
-   14 |    logic unu3 = 0;
-      |          ^~~~
+%Warning-UNUSEDSIGNAL: t/t_cover_unused_bad.v:14:8: Signal is not used: 'unu3'
+                                                  : ... note: In instance 't'
+   14 |    bit unu3 = 0;
+      |        ^~~~
                        ... For warning description see https://verilator.org/warn/UNUSEDSIGNAL?v=latest
                        ... Use "/* verilator lint_off UNUSEDSIGNAL */" and lint_on around source to disable this message.
 %Error: Exiting due to

test_regress/t/t_cover_unused_bad.v

@@ -11,7 +11,7 @@ module t (/*AUTOARG*/
 
    input clk;
 
-   logic unu3 = 0;
+   bit unu3 = 0;
 
    logic isusd = 0;
    cover property (@(posedge clk) isusd == 0);

test_regress/t/t_covergroup_args.py

@@ -0,0 +1,16 @@
+#!/usr/bin/env python3
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2025 by Wilson Snyder. This program is free software; you
+# can redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+# SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
+
+import vltest_bootstrap
+
+test.scenarios('vlt')
+
+test.compile()
+
+test.passes()

test_regress/t/t_covergroup_args.v

@@ -0,0 +1,19 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2025 by Antmicro.
+// SPDX-License-Identifier: CC0-1.0
+
+/* verilator lint_off COVERIGN */
+module t;
+    covergroup cgArgs(int var1, int var2=42);
+
+    endgroup
+
+    cgArgs cov1 = new(69, 77);
+    cgArgs cov2 = new(69);
+    function x();
+        cov1.sample();
+        cov2.get_coverage();
+    endfunction;
+endmodule

test_regress/t/t_covergroup_extends.py

@@ -0,0 +1,16 @@
+#!/usr/bin/env python3
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2025 by Wilson Snyder. This program is free software; you
+# can redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+# SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
+
+import vltest_bootstrap
+
+test.scenarios('vlt')
+
+test.compile()
+
+test.passes()

test_regress/t/t_covergroup_extends.v

@@ -0,0 +1,39 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2025 by Antmicro.
+// SPDX-License-Identifier: CC0-1.0
+
+/* verilator lint_off COVERIGN */
+module t;
+    class base;
+        enum {red, green, blue} color;
+        covergroup g1 (bit [3:0] a) with function sample(bit b);
+            option.weight       = 10;
+            option.per_instance = 1;
+            coverpoint a;
+            coverpoint b;
+            c: coverpoint color;
+        endgroup
+        function new();
+            g1 = new(0);
+        endfunction
+    endclass
+
+    class derived extends base;
+        bit d;
+        covergroup extends g1;
+            option.weight = 1;  // overrides the weight from base g1
+                                // uses per_instance = 1 from base g1
+            c: coverpoint color // overrides the c coverpoint in base g1
+            {
+                ignore_bins ignore = {blue};
+            }
+            coverpoint d;       // adds new coverpoint
+            cross a, d;         // crosses new coverpoint with inherited one
+        endgroup :g1
+        function new();
+            super.new();
+        endfunction
+    endclass
+endmodule

test_regress/t/t_covergroup_extends_newfirst.py

@@ -0,0 +1,16 @@
+#!/usr/bin/env python3
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2025 by Wilson Snyder. This program is free software; you
+# can redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+# SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
+
+import vltest_bootstrap
+
+test.scenarios('vlt')
+
+test.compile()
+
+test.passes()

test_regress/t/t_covergroup_extends_newfirst.v

@@ -0,0 +1,39 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2025 by Antmicro.
+// SPDX-License-Identifier: CC0-1.0
+
+/* verilator lint_off COVERIGN */
+module t;
+    class base;
+        function new();
+            g1 = new(0);
+        endfunction
+        enum {red, green, blue} color;
+        covergroup g1 (bit [3:0] a) with function sample(bit b);
+            option.weight       = 10;
+            option.per_instance = 1;
+            coverpoint a;
+            coverpoint b;
+            c: coverpoint color;
+        endgroup
+    endclass
+
+    class derived extends base;
+        bit d;
+        function new();
+            super.new();
+        endfunction
+        covergroup extends g1;
+            option.weight = 1;  // overrides the weight from base g1
+                                // uses per_instance = 1 from base g1
+            c: coverpoint color // overrides the c coverpoint in base g1
+            {
+                ignore_bins ignore = {blue};
+            }
+            coverpoint d;       // adds new coverpoint
+            cross a, d;         // crosses new coverpoint with inherited one
+        endgroup :g1
+    endclass
+endmodule

test_regress/t/t_covergroup_func_override_bad.out

@@ -0,0 +1,5 @@
+%Error: t/t_covergroup_func_override_bad.v:10:5: syntax error, unexpected function
+   10 |     function sample();
+      |     ^~~~~~~~
+        ... See the manual at https://verilator.org/verilator_doc.html?v=latest for more assistance.
+%Error: Exiting due to

test_regress/t/t_covergroup_func_override_bad.py

@@ -0,0 +1,20 @@
+#!/usr/bin/env python3
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2025 by Wilson Snyder. This program is free software; you
+# can redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+# SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
+
+import vltest_bootstrap
+
+test.scenarios('simulator')
+
+if test.vlt_all:
+    test.lint(fails=True, expect_filename=test.golden_filename)
+else:
+    test.compile(nc_flags2=["-coverage", "functional"])
+    test.execute()
+
+test.passes()

test_regress/t/t_covergroup_func_override_bad.v

@@ -0,0 +1,17 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2025 by Antmicro.
+// SPDX-License-Identifier: CC0-1.0
+
+/* verilator lint_off COVERIGN */
+module t();
+    covergroup cg;
+    function sample();
+
+    endfunction
+    function get_coverage();
+
+    endfunction
+    endgroup
+endmodule

test_regress/t/t_covergroup_in_class.py

@@ -0,0 +1,16 @@
+#!/usr/bin/env python3
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2025 by Wilson Snyder. This program is free software; you
+# can redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+# SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
+
+import vltest_bootstrap
+
+test.scenarios('vlt')
+
+test.compile()
+
+test.passes()

test_regress/t/t_covergroup_in_class.v

@@ -0,0 +1,18 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2025 by Antmicro.
+// SPDX-License-Identifier: CC0-1.0
+
+/* verilator lint_off COVERIGN */
+class myClass;
+    covergroup embeddedCg;
+
+    endgroup
+
+    function new();
+        embeddedCg = new();
+        embeddedCg.sample();
+        embeddedCg.get_coverage();
+    endfunction
+endclass

test_regress/t/t_covergroup_in_class_colliding.py

@@ -0,0 +1,16 @@
+#!/usr/bin/env python3
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2025 by Wilson Snyder. This program is free software; you
+# can redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+# SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
+
+import vltest_bootstrap
+
+test.scenarios('vlt')
+
+test.compile()
+
+test.passes()

test_regress/t/t_covergroup_in_class_colliding.v

@@ -0,0 +1,30 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2025 by Antmicro.
+// SPDX-License-Identifier: CC0-1.0
+
+/* verilator lint_off COVERIGN */
+class myClass;
+    covergroup embeddedCg;
+
+    endgroup
+
+    function new();
+        embeddedCg = new();
+        embeddedCg.sample();
+        embeddedCg.get_coverage();
+    endfunction
+endclass
+
+class secondClass;
+    covergroup embeddedCg;
+
+    endgroup
+
+    function new();
+        embeddedCg = new();
+        embeddedCg.sample();
+        embeddedCg.get_coverage();
+    endfunction
+endclass

test_regress/t/t_covergroup_in_class_duplicate_bad.out

@@ -0,0 +1,8 @@
+%Error: t/t_covergroup_in_class_duplicate_bad.v:13:16: Duplicate declaration of CLASS '__vlAnonCG_embeddedCg': '__vlAnonCG_embeddedCg'
+   13 |     covergroup embeddedCg;
+      |                ^~~~~~~~~~
+        t/t_covergroup_in_class_duplicate_bad.v:9:16: ... Location of original declaration
+    9 |     covergroup embeddedCg;
+      |                ^~~~~~~~~~
+        ... See the manual at https://verilator.org/verilator_doc.html?v=latest for more assistance.
+%Error: Exiting due to

test_regress/t/t_covergroup_in_class_duplicate_bad.py

@@ -0,0 +1,16 @@
+#!/usr/bin/env python3
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2025 by Wilson Snyder. This program is free software; you
+# can redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+# SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
+
+import vltest_bootstrap
+
+test.scenarios('simulator')
+
+test.compile(fails=True, expect_filename=test.golden_filename)
+
+test.passes()

test_regress/t/t_covergroup_in_class_duplicate_bad.v

@@ -0,0 +1,16 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2025 by Antmicro.
+// SPDX-License-Identifier: CC0-1.0
+
+/* verilator lint_off COVERIGN */
+class myClass;
+    covergroup embeddedCg;
+
+    endgroup
+
+    covergroup embeddedCg;
+
+    endgroup
+endclass

test_regress/t/t_covergroup_new_override_bad.out

@@ -0,0 +1,5 @@
+%Error: t/t_covergroup_new_override_bad.v:10:5: syntax error, unexpected function
+   10 |     function new();
+      |     ^~~~~~~~
+        ... See the manual at https://verilator.org/verilator_doc.html?v=latest for more assistance.
+%Error: Exiting due to

test_regress/t/t_covergroup_new_override_bad.py

@@ -0,0 +1,20 @@
+#!/usr/bin/env python3
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2025 by Wilson Snyder. This program is free software; you
+# can redistribute it and/or modify it under the terms of either the GNU
+# Lesser General Public License Version 3 or the Perl Artistic License
+# Version 2.0.
+# SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
+
+import vltest_bootstrap
+
+test.scenarios('simulator')
+
+if test.vlt_all:
+    test.lint(fails=True, expect_filename=test.golden_filename)
+else:
+    test.compile(nc_flags2=["-coverage", "functional"])
+    test.execute()
+
+test.passes()

test_regress/t/t_covergroup_new_override_bad.v

@@ -0,0 +1,14 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2025 by Antmicro.
+// SPDX-License-Identifier: CC0-1.0
+
+/* verilator lint_off COVERIGN */
+module t();
+    covergroup cg;
+    function new();
+
+    endfunction
+    endgroup
+endmodule