Merge d16f3988de into 574c69c092

docs/CONTRIBUTORS

@@ -105,6 +105,7 @@ Jamey Hicks
 Jamie Iles
 Jan Van Winkel
 Jean Berniolles
+Jens Yuechao Liu
 Jeremy Bennett
 Jesse Taube
 Jevin Sweval

docs/guide/exe_verilator.rst

@@ -719,6 +719,11 @@ Summary:
    automatically. Variables explicitly annotated with
    :option:`/*verilator&32;split_var*/` are still split.
 
+.. option:: --fslice-element-limit
+
+   Rarely needed.  Set the maximum array size (number of elements)
+   for slice optimization to avoid excessive memory usage.
+
 .. option:: -future0 <option>
 
    Rarely needed.  Suppress an unknown Verilator option for an option that

src/V3AstNodeOther.h

@@ -941,6 +941,7 @@ public:
     void dump(std::ostream& str) const override;
     void dumpJson(std::ostream& str) const override;
     string name() const override VL_MT_STABLE { return m_name; }  // * = Scope name
+    void name(const string& name) override { m_name = name; }  // * = Scope name
     bool isGateOptimizable() const override { return false; }
     bool isPredictOptimizable() const override { return false; }
     bool maybePointedTo() const override VL_MT_SAFE { return true; }
@@ -1871,7 +1872,7 @@ class AstVar final : public AstNode {
     bool m_ignorePostWrite : 1;  // Ignore writes in 'Post' blocks during ordering
     bool m_ignoreSchedWrite : 1;  // Ignore writes in scheduling (for special optimizations)
     bool m_dfgMultidriven : 1;  // Singal is multidriven, used by DFG to avoid repeat processing
-
+    bool m_globalConstrained : 1;  // Global constraint per IEEE 1800-2023 18.5.8
     void init() {
         m_ansi = false;
         m_declTyped = false;
@@ -1921,6 +1922,7 @@ class AstVar final : public AstNode {
         m_ignorePostWrite = false;
         m_ignoreSchedWrite = false;
         m_dfgMultidriven = false;
+        m_globalConstrained = false;
     }
 
 public:
@@ -2085,7 +2087,8 @@ public:
     void setIgnoreSchedWrite() { m_ignoreSchedWrite = true; }
     bool dfgMultidriven() const { return m_dfgMultidriven; }
     void setDfgMultidriven() { m_dfgMultidriven = true; }
-
+    void globalConstrained(bool flag) { m_globalConstrained = flag; }
+    bool globalConstrained() const { return m_globalConstrained; }
     // METHODS
     void name(const string& name) override { m_name = name; }
     void tag(const string& text) override { m_tag = text; }

src/V3Options.cpp

@@ -1458,13 +1458,16 @@ void V3Options::parseOptsList(FileLine* fl, const string& optdir, int argc,
     DECL_OPTION("-freloop", FOnOff, &m_fReloop);
     DECL_OPTION("-freorder", FOnOff, &m_fReorder);
     DECL_OPTION("-fslice", FOnOff, &m_fSlice);
+    DECL_OPTION("-fslice-element-limit", CbVal, [this, fl](const char* valp) {
+        m_fSliceElementLimit = std::atoi(valp);
+        if (m_fSliceElementLimit < 0) fl->v3fatal("--fslice-element-limit must be >= 0: " << valp);
+    });
     DECL_OPTION("-fsplit", FOnOff, &m_fSplit);
     DECL_OPTION("-fsubst", FOnOff, &m_fSubst);
     DECL_OPTION("-fsubst-const", FOnOff, &m_fSubstConst);
     DECL_OPTION("-ftable", FOnOff, &m_fTable);
     DECL_OPTION("-ftaskify-all-forked", FOnOff, &m_fTaskifyAll).undocumented();  // Debug
     DECL_OPTION("-fvar-split", FOnOff, &m_fVarSplit);
-
     DECL_OPTION("-G", CbPartialMatch, [this](const char* optp) { addParameter(optp, false); });
     DECL_OPTION("-gate-stmts", Set, &m_gateStmts);
     DECL_OPTION("-gdb", CbCall, []() {});  // Processed only in bin/verilator shell

src/V3Options.h

@@ -413,6 +413,7 @@ private:
     bool m_fReloop;      // main switch: -fno-reloop: reform loops
     bool m_fReorder;     // main switch: -fno-reorder: reorder assignments in blocks
     bool m_fSlice = true;  // main switch: -fno-slice: array assignment slicing
+    int  m_fSliceElementLimit = 256;  // main switch: --fslice-element-limit
     bool m_fSplit;       // main switch: -fno-split: always assignment splitting
     bool m_fSubst;       // main switch: -fno-subst: substitute expression temp values
     bool m_fSubstConst;  // main switch: -fno-subst-const: final constant substitution
@@ -726,6 +727,7 @@ public:
     bool fReloop() const { return m_fReloop; }
     bool fReorder() const { return m_fReorder; }
     bool fSlice() const { return m_fSlice; }
+    int fSliceElementLimit() const { return m_fSliceElementLimit; }
     bool fSplit() const { return m_fSplit; }
     bool fSubst() const { return m_fSubst; }
     bool fSubstConst() const { return m_fSubstConst; }

src/V3Randomize.cpp

@@ -54,10 +54,17 @@ VL_DEFINE_DEBUG_FUNCTIONS;
 enum ClassRandom : uint8_t {
     NONE,  // randomize() is not called
     IS_RANDOMIZED,  // randomize() is called
+    IS_RANDOMIZED_GLOBAL,  // randomize() is called with global constraints
     IS_RANDOMIZED_INLINE,  // randomize() with args is called
     IS_STD_RANDOMIZED,  // std::randomize() is called
 };
 
+// ######################################################################
+// Constants for global constraint processing
+
+static constexpr const char* GLOBAL_CONSTRAINT_SEPARATOR = "__DT__";
+static constexpr const char* BASIC_RANDOMIZE_FUNC_NAME = "__VBasicRand";
+
 // ######################################################################
 // Establishes the target of a rand_mode() call
 
@@ -138,6 +145,9 @@ class RandomizeMarkVisitor final : public VNVisitor {
     AstNodeModule* m_modp;  // Current module
     AstNodeStmt* m_stmtp = nullptr;  // Current statement
     std::set<AstNodeVarRef*> m_staticRefs;  // References to static variables under `with` clauses
+    AstWith* m_withp = nullptr;  // Current 'with' constraint node
+    std::vector<AstConstraint*> m_clonedConstraints;  // List of cloned global constraints
+    std::unordered_set<const AstVar*> m_processedVars;  // Track by variable instance, not class
 
     // METHODS
     void markMembers(const AstClass* nodep) {
@@ -196,18 +206,145 @@ class RandomizeMarkVisitor final : public VNVisitor {
             staticRefp->classOrPackagep(VN_AS(staticRefp->varp()->user2p(), NodeModule));
         }
     }
+    void markNestedGlobalConstrainedRecurse(AstNode* nodep) {
+        if (const AstVarRef* const refp = VN_CAST(nodep, VarRef)) {
+            AstVar* const varp = refp->varp();
+            if (varp->globalConstrained()) return;
+            varp->globalConstrained(true);
+        } else if (const AstMemberSel* const memberSelp = VN_CAST(nodep, MemberSel)) {
+            if (memberSelp->varp()) {
+                AstVar* const varp = memberSelp->varp();
+                if (varp->globalConstrained()) return;
+                varp->globalConstrained(true);
+            }
+            markNestedGlobalConstrainedRecurse(memberSelp->fromp());
+        }
+    }
+
+    // Build MemberSel chain from variable path
+    AstNodeExpr* buildMemberSelChain(AstVarRef* rootVarRefp, const std::vector<AstVar*>& path) {
+        AstNodeExpr* exprp = rootVarRefp->cloneTree(false);
+        for (AstVar* memberVarp : path) {
+            AstMemberSel* memberSelp
+                = new AstMemberSel{rootVarRefp->fileline(), exprp, memberVarp};
+            memberSelp->user2p(m_classp);
+            exprp = memberSelp;
+        }
+        return exprp;
+    }
+
+    // Process a single constraint during nested constraint cloning
+    void processNestedConstraint(AstConstraint* const constrp, AstVarRef* rootVarRefp,
+                                 const std::vector<AstVar*>& newPath) {
+        std::string pathPrefix = rootVarRefp->name();
+        for (AstVar* pathMemberVarp : newPath) {
+            pathPrefix += GLOBAL_CONSTRAINT_SEPARATOR + pathMemberVarp->name();
+        }
+
+        const std::string newName = pathPrefix + GLOBAL_CONSTRAINT_SEPARATOR + constrp->name();
+
+        for (const AstConstraint* existingConstrp : m_clonedConstraints) {
+            if (existingConstrp->name() == newName) {
+                // Multiple paths lead to same constraint - unsupported pattern
+                std::string fullPath = rootVarRefp->name();
+                for (AstVar* pathVar : newPath) { fullPath += "." + pathVar->name(); }
+                constrp->v3warn(E_UNSUPPORTED, "Unsupported: One variable '"
+                                                   << fullPath
+                                                   << "' cannot have multiple global constraints");
+                return;
+            }
+        }
+
+        AstConstraint* const cloneConstrp = constrp->cloneTree(false);
+        cloneConstrp->name(newName);
+        cloneConstrp->foreach([&](AstVarRef* varRefp) {
+            AstNodeExpr* const chainp = buildMemberSelChain(rootVarRefp, newPath);
+            AstMemberSel* const finalSelp
+                = new AstMemberSel{varRefp->fileline(), chainp, varRefp->varp()};
+            finalSelp->user2p(m_classp);
+            varRefp->replaceWith(finalSelp);
+            VL_DO_DANGLING(varRefp->deleteTree(), varRefp);
+        });
+
+        m_clonedConstraints.push_back(cloneConstrp);
+    }
+
+    // Clone constraints from nested rand class members
+    void cloneNestedConstraintsRecurse(AstVarRef* rootVarRefp, AstClass* classp,
+                                       const std::vector<AstVar*>& pathToClass) {
+        for (AstNode* memberNodep = classp->membersp(); memberNodep;
+             memberNodep = memberNodep->nextp()) {
+            AstVar* const memberVarp = VN_CAST(memberNodep, Var);
+            if (!memberVarp) continue;
+            if (!memberVarp->rand().isRandomizable()) continue;
+            const AstClassRefDType* const memberClassRefp
+                = VN_CAST(memberVarp->dtypep()->skipRefp(), ClassRefDType);
+            if (!memberClassRefp || !memberClassRefp->classp()) continue;
+
+            AstClass* nestedClassp = memberClassRefp->classp();
+
+            std::vector<AstVar*> newPath = pathToClass;
+            newPath.push_back(memberVarp);
+            // Replace all variable references inside the cloned constraint with proper
+            // member selections
+            nestedClassp->foreachMember(
+                [&](AstClass* const containingClassp, AstConstraint* const constrp) {
+                    processNestedConstraint(constrp, rootVarRefp, newPath);
+                });
+
+            cloneNestedConstraintsRecurse(rootVarRefp, nestedClassp, newPath);
+        }
+    }
+
+    void cloneNestedConstraints(AstVarRef* rootVarRefp, AstClass* rootClass) {
+        std::vector<AstVar*> emptyPath;
+        cloneNestedConstraintsRecurse(rootVarRefp, rootClass, emptyPath);
+    }
+
+    void nameManipulation(AstVarRef* fromp, AstConstraint* cloneCons) {
+        cloneCons->name(fromp->name() + GLOBAL_CONSTRAINT_SEPARATOR + cloneCons->name());
+        cloneCons->foreach([&](AstVarRef* varRefp) {
+            AstVarRef* const clonedFromp = fromp->cloneTree(false);
+            AstMemberSel* const varMemberp
+                = new AstMemberSel{cloneCons->fileline(), clonedFromp, varRefp->varp()};
+            varMemberp->user2p(m_classp);
+            varRefp->replaceWith(varMemberp);
+            VL_DO_DANGLING(varRefp->deleteTree(), varRefp);
+        });
+    }
+
+    // Process a globally constrained variable by cloning its constraints
+    void processGlobalConstraint(AstVarRef* varRefp, AstClass* gConsClass) {
+        AstVar* const objVar = varRefp->varp();
+
+        // Process per-variable (object instance), not per-class
+        // This allows multiple objects of the same class (e.g., obj1 and obj2 of type Sub)
+        if (m_processedVars.insert(objVar).second) {
+            // Clone constraints from the top-level class (e.g., Level1 for obj_a)
+            gConsClass->foreachMember([&](AstClass* const classp, AstConstraint* const constrp) {
+                AstConstraint* const cloneConstrp = constrp->cloneTree(false);
+                nameManipulation(varRefp, cloneConstrp);
+                m_clonedConstraints.push_back(cloneConstrp);
+            });
+
+            cloneNestedConstraints(varRefp, gConsClass);
+        }
+    }
 
     // VISITORS
     void visit(AstClass* nodep) override {
         VL_RESTORER(m_classp);
         VL_RESTORER(m_modp);
+        VL_RESTORER(m_clonedConstraints);
         m_modp = m_classp = nodep;
         iterateChildrenConst(nodep);
         if (nodep->extendsp()) {
-            // Save pointer to derived class
+            // Record derived class for inheritance hierarchy tracking
             const AstClass* const basep = nodep->extendsp()->classp();
             m_baseToDerivedMap[basep].insert(nodep);
         }
+        for (AstConstraint* const constrp : m_clonedConstraints) m_classp->addStmtsp(constrp);
+        m_clonedConstraints.clear();
     }
     void visit(AstNodeStmt* nodep) override {
         VL_RESTORER(m_stmtp);
@@ -464,8 +601,52 @@ class RandomizeMarkVisitor final : public VNVisitor {
         // of type AstLambdaArgRef. They are randomized too.
         const bool randObject = nodep->fromp()->user1() || VN_IS(nodep->fromp(), LambdaArgRef);
         nodep->user1(randObject && nodep->varp()->rand().isRandomizable());
+
+        if (m_withp) {
+            AstNode* backp = m_withp;
+            while (backp->backp()) {
+                if (const AstMethodCall* const callp = VN_CAST(backp, MethodCall)) {
+                    AstClassRefDType* classdtype
+                        = VN_AS(callp->fromp()->dtypep()->skipRefp(), ClassRefDType);
+                    nodep->user2p(classdtype->classp());
+                    break;
+                }
+                backp = backp->backp();
+            }
+        } else {
             nodep->user2p(m_modp);
         }
+        if (randObject && nodep->varp()
+            && nodep->varp()->rand().isRandomizable()) {  // Process global constraints
+            if (m_classp && m_classp->user1() == IS_RANDOMIZED) {
+                m_classp->user1(IS_RANDOMIZED_GLOBAL);
+            }
+            // Mark the entire nested chain as participating in global constraints
+            if (VN_IS(nodep->fromp(), VarRef) || VN_IS(nodep->fromp(), MemberSel)) {
+                markNestedGlobalConstrainedRecurse(nodep->fromp());
+            } else if (VN_IS(nodep->fromp(), ArraySel)) {
+                nodep->v3warn(E_UNSUPPORTED, "Unsupported: " << nodep->prettyTypeName()
+                                                             << " within a global constraint");
+            }
+            // Global constraint processing algorithm:
+            // 1. Detect globally constrained object variables in randomized classes
+            // 2. Clone constraint trees from the constrained object's class
+            // 3. Rename cloned constraints with object prefix (obj.var format)
+            // 4. Insert cloned constraints into current class for solver processing
+            // 5. Use basic randomization for non-constrained variables to avoid recursion
+
+            // Extract and validate components early to avoid repeated type checks
+            AstVarRef* const varRefp = VN_CAST(nodep->fromp(), VarRef);
+            if (!varRefp) return;
+
+            const AstClassRefDType* const classRefp
+                = VN_AS(varRefp->dtypep()->skipRefp(), ClassRefDType);
+
+            if (nodep->user1() && varRefp->varp()->globalConstrained()) {
+                processGlobalConstraint(varRefp, classRefp->classp());
+            }
+        }
+    }
     void visit(AstNodeModule* nodep) override {
         VL_RESTORER(m_modp);
         m_modp = nodep;
@@ -479,6 +660,11 @@ class RandomizeMarkVisitor final : public VNVisitor {
         nodep->user2p(m_modp);
         iterateChildrenConst(nodep);
     }
+    void visit(AstWith* nodep) override {
+        VL_RESTORER(m_withp);
+        m_withp = nodep;
+        iterateChildrenConst(nodep);
+    }
 
     void visit(AstNodeExpr* nodep) override {
         iterateChildrenConst(nodep);
@@ -519,6 +705,20 @@ class ConstraintExprVisitor final : public VNVisitor {
     bool m_structSel = false;  // Marks when inside structSel
                                // (used to format "%@.%@" for struct arrays)
 
+    // Build full path for a MemberSel chain (e.g., "obj.l2.l3.l4")
+    std::string buildMemberPath(const AstMemberSel* const memberSelp) {
+        const AstNode* fromp = memberSelp->fromp();
+        if (const AstVarRef* const refp = VN_CAST(fromp, VarRef)) {
+            // Base case: reached root VarRef
+            return refp->name() + "." + memberSelp->name();
+        } else if (const AstMemberSel* const selp = VN_CAST(fromp, MemberSel)) {
+            // Recursive case: build path from outer levels
+            return buildMemberPath(selp) + "." + memberSelp->name();
+        }
+        memberSelp->v3fatalSrc("Unexpected node type in MemberSel chain");
+        return "";
+    }
+
     AstSFormatF* getConstFormat(AstNodeExpr* nodep) {
         return new AstSFormatF{nodep->fileline(), (nodep->width() & 3) ? "#b%b" : "#x%x", false,
                                nodep};
@@ -641,19 +841,30 @@ class ConstraintExprVisitor final : public VNVisitor {
                 CONSTRAINTIGN,
                 "Size constraint combined with element constraint may not work correctly");
         }
-        AstMemberSel* membersel = VN_IS(nodep->backp(), MemberSel)
-                                      ? VN_AS(nodep->backp(), MemberSel)->cloneTree(false)
-                                      : nullptr;
+
+        // Check if this variable is marked as globally constrained
+        const bool isGlobalConstrained = nodep->varp()->globalConstrained();
+
+        AstMemberSel* membersel = nullptr;
+        std::string smtName;
+        if (isGlobalConstrained && VN_IS(nodep->backp(), MemberSel)) {
+            // For global constraints: build complete path from topmost MemberSel
+            AstNode* topMemberSel = nodep->backp();
+            while (VN_IS(topMemberSel->backp(), MemberSel)) {
+                topMemberSel = topMemberSel->backp();
+            }
+            membersel = VN_AS(topMemberSel, MemberSel)->cloneTree(false);
+            smtName = buildMemberPath(membersel);
+        } else {
+            // No MemberSel: just variable name
+            smtName = nodep->name();
+        }
+
         if (membersel) varp = membersel->varp();
         AstNodeModule* const classOrPackagep = nodep->classOrPackagep();
         const RandomizeMode randMode = {.asInt = varp->user1()};
         if (!randMode.usesMode && editFormat(nodep)) return;
 
-        // In SMT just variable name, but we also ensure write_var for the variable
-        const std::string smtName = membersel
-                                        ? membersel->fromp()->name() + "." + membersel->name()
-                                        : nodep->name();  // Can be anything unique
-
         VNRelinker relinker;
         nodep->unlinkFrBack(&relinker);
         AstNodeExpr* exprp = new AstSFormatF{nodep->fileline(), smtName, false, nullptr};
@@ -666,12 +877,18 @@ class ConstraintExprVisitor final : public VNVisitor {
                 VCMethod::ARRAY_AT, new AstConst{nodep->fileline(), randMode.index}};
             atp->dtypeSetUInt32();
             exprp = new AstCond{varp->fileline(), atp, exprp, constFormatp};
-        } else {
+        } else if (!membersel || !isGlobalConstrained) {
+            // Only delete nodep here if it's not a global constraint
+            // Global constraints need nodep for write_var processing
             VL_DO_DANGLING(pushDeletep(nodep), nodep);
         }
         relinker.relink(exprp);
 
-        if (!varp->user3()) {
+        // For global constraints: always call write_var with full path even if varp->user3() is
+        // set For normal constraints: only call write_var if varp->user3() is not set
+        if (!varp->user3() || (membersel && nodep->varp()->globalConstrained())) {
+            // For global constraints, delete nodep here after processing
+            if (membersel && isGlobalConstrained) VL_DO_DANGLING(pushDeletep(nodep), nodep);
             AstCMethodHard* const methodp = new AstCMethodHard{
                 varp->fileline(),
                 new AstVarRef{varp->fileline(), VN_AS(m_genp->user2p(), NodeModule), m_genp,
@@ -693,10 +910,14 @@ class ConstraintExprVisitor final : public VNVisitor {
             methodp->dtypeSetVoid();
             AstClass* const classp
                 = membersel ? VN_AS(membersel->user2p(), Class) : VN_AS(varp->user2p(), Class);
+            if (membersel) {
+                methodp->addPinsp(membersel);
+            } else {
                 AstVarRef* const varRefp
                     = new AstVarRef{varp->fileline(), classp, varp, VAccess::WRITE};
                 varRefp->classOrPackagep(classOrPackagep);
-            membersel ? methodp->addPinsp(membersel) : methodp->addPinsp(varRefp);
+                methodp->addPinsp(varRefp);
+            }
             AstNodeDType* tmpDtypep = varp->dtypep();
             while (VN_IS(tmpDtypep, UnpackArrayDType) || VN_IS(tmpDtypep, DynArrayDType)
                    || VN_IS(tmpDtypep, QueueDType) || VN_IS(tmpDtypep, AssocArrayDType))
@@ -911,8 +1132,21 @@ class ConstraintExprVisitor final : public VNVisitor {
         editSMT(nodep, nodep->fromp(), indexp);
     }
     void visit(AstMemberSel* nodep) override {
-        if (nodep->user1()) {
-            nodep->v3warn(CONSTRAINTIGN, "Global constraints ignored (unsupported)");
+        if (nodep->varp()->rand().isRandomizable() && nodep->fromp()) {
+            AstNode* rootNode = nodep->fromp();
+            while (const AstMemberSel* const selp = VN_CAST(rootNode, MemberSel))
+                rootNode = selp->fromp();
+            // Check if the root variable participates in global constraints
+            if (const AstVarRef* const varRefp = VN_CAST(rootNode, VarRef)) {
+                AstVar* const constrainedVar = varRefp->varp();
+                if (constrainedVar->globalConstrained()) {
+                    // Global constraint - unwrap the MemberSel
+                    iterateChildren(nodep);
+                    nodep->replaceWith(nodep->fromp()->unlinkFrBack());
+                    VL_DO_DANGLING(nodep->deleteTree(), nodep);
+                    return;
+                }
+            }
         }
         // Handle MemberSel references created by captureRefByThis()
         if (VN_IS(nodep->fromp(), VarRef)
@@ -1943,9 +2177,18 @@ class RandomizeVisitor final : public VNVisitor {
                     return;
                 }
                 AstFunc* const memberFuncp
-                    = V3Randomize::newRandomizeFunc(m_memberMap, classRefp->classp());
+                    = memberVarp->globalConstrained()
+                          ? V3Randomize::newRandomizeFunc(m_memberMap, classRefp->classp(),
+                                                          BASIC_RANDOMIZE_FUNC_NAME)
+                          : V3Randomize::newRandomizeFunc(m_memberMap, classRefp->classp());
                 AstMethodCall* const callp
-                    = new AstMethodCall{fl, new AstVarRef{fl, classp, memberVarp, VAccess::WRITE},
+                    = memberVarp->globalConstrained()
+                          ? new AstMethodCall{fl,
+                                              new AstVarRef{fl, classp, memberVarp,
+                                                            VAccess::WRITE},
+                                              BASIC_RANDOMIZE_FUNC_NAME, nullptr}
+                          : new AstMethodCall{
+                                fl, new AstVarRef{fl, classp, memberVarp, VAccess::WRITE},
                                 "randomize", nullptr};
                 callp->taskp(memberFuncp);
                 callp->dtypeFrom(memberFuncp);
@@ -2123,6 +2366,8 @@ class RandomizeVisitor final : public VNVisitor {
         if (!nodep->user1()) return;  // Doesn't need randomize, or already processed
         UINFO(9, "Define randomize() for " << nodep);
         nodep->baseMostClassp()->needRNG(true);
+
+        const bool globalConstrained = nodep->user1() == IS_RANDOMIZED_GLOBAL;
         AstFunc* const randomizep = V3Randomize::newRandomizeFunc(m_memberMap, nodep);
         AstVar* const fvarp = VN_AS(randomizep->fvarp(), Var);
         addPrePostCall(nodep, randomizep, "pre_randomize");
@@ -2184,7 +2429,18 @@ class RandomizeVisitor final : public VNVisitor {
         }
 
         AstVarRef* const fvarRefp = new AstVarRef{fl, fvarp, VAccess::WRITE};
+
+        // For global constraints: call basic randomize first (without global constraints)
+        if (globalConstrained) {
+            AstFunc* const basicRandomizep
+                = V3Randomize::newRandomizeFunc(m_memberMap, nodep, BASIC_RANDOMIZE_FUNC_NAME);
+            addBasicRandomizeBody(basicRandomizep, nodep, randModeVarp);
+            AstFuncRef* const basicRandomizeCallp = new AstFuncRef{fl, basicRandomizep, nullptr};
+            randomizep->addStmtsp(new AstAssign{fl, fvarRefp, basicRandomizeCallp});
+        } else {
+            // For normal classes: use beginValp (standard flow)
             randomizep->addStmtsp(new AstAssign{fl, fvarRefp, beginValp});
+        }
 
         if (AstTask* const resizeAllTaskp
             = VN_AS(m_memberMap.findMember(nodep, "__Vresize_constrained_arrays"), Task)) {
@@ -2192,15 +2448,23 @@ class RandomizeVisitor final : public VNVisitor {
             randomizep->addStmtsp(resizeTaskRefp->makeStmt());
         }
 
-        AstFunc* const basicRandomizep
-            = V3Randomize::newRandomizeFunc(m_memberMap, nodep, "__Vbasic_randomize");
-        addBasicRandomizeBody(basicRandomizep, nodep, randModeVarp);
-        AstFuncRef* const basicRandomizeCallp = new AstFuncRef{fl, basicRandomizep, nullptr};
         AstVarRef* const fvarRefReadp = fvarRefp->cloneTree(false);
         fvarRefReadp->access(VAccess::READ);
 
+        // For global constraints: combine with solver result (beginValp)
+        // For normal classes: call basic randomize after resize
+        if (globalConstrained) {
             randomizep->addStmtsp(new AstAssign{fl, fvarRefp->cloneTree(false),
+                                                new AstAnd{fl, fvarRefReadp, beginValp}});
+        } else {
+            AstFunc* const basicRandomizep
+                = V3Randomize::newRandomizeFunc(m_memberMap, nodep, BASIC_RANDOMIZE_FUNC_NAME);
+            addBasicRandomizeBody(basicRandomizep, nodep, randModeVarp);
+            AstFuncRef* const basicRandomizeCallp = new AstFuncRef{fl, basicRandomizep, nullptr};
+            randomizep->addStmtsp(
+                new AstAssign{fl, fvarRefp->cloneTree(false),
                               new AstAnd{fl, fvarRefReadp, basicRandomizeCallp}});
+        }
         addPrePostCall(nodep, randomizep, "post_randomize");
         nodep->user1(false);
     }
@@ -2417,7 +2681,7 @@ class RandomizeVisitor final : public VNVisitor {
         randomizeFuncp->addStmtsp(localGenp);
 
         AstFunc* const basicRandomizeFuncp
-            = V3Randomize::newRandomizeFunc(m_memberMap, classp, "__Vbasic_randomize");
+            = V3Randomize::newRandomizeFunc(m_memberMap, classp, BASIC_RANDOMIZE_FUNC_NAME);
         AstFuncRef* const basicRandomizeFuncCallp
             = new AstFuncRef{nodep->fileline(), basicRandomizeFuncp, nullptr};
 

src/V3Slice.cpp

@@ -58,6 +58,7 @@ class SliceVisitor final : public VNVisitor {
 
     // STATE - across all visitors
     VDouble0 m_statAssigns;  // Statistic tracking
+    VDouble0 m_statSliceElementSkips;  // Statistic tracking
 
     // STATE - for current visit position (use VL_RESTORER)
     AstNode* m_assignp = nullptr;  // Assignment we are under
@@ -248,6 +249,14 @@ class SliceVisitor final : public VNVisitor {
             return false;
         }
 
+        // Skip optimization if array is too large
+        const int elements = arrayp->rangep()->elementsConst();
+        const int elementLimit = v3Global.opt.fSliceElementLimit();
+        if (elements > elementLimit && elementLimit > 0) {
+            ++m_statSliceElementSkips;
+            return false;
+        }
+
         UINFO(4, "Slice optimizing " << nodep);
         ++m_statAssigns;
 
@@ -256,7 +265,6 @@ class SliceVisitor final : public VNVisitor {
         // Assign of an ascending range slice to a descending range one must reverse
         // the elements
         AstNodeAssign* newlistp = nullptr;
-        const int elements = arrayp->rangep()->elementsConst();
         for (int elemIdx = 0; elemIdx < elements; ++elemIdx) {
             // Original node is replaced, so it is safe to copy it one time even if it is impure.
             AstNodeAssign* const newp
@@ -383,6 +391,8 @@ public:
     explicit SliceVisitor(AstNetlist* nodep) { iterate(nodep); }
     ~SliceVisitor() override {
         V3Stats::addStat("Optimizations, Slice array assignments", m_statAssigns);
+        V3Stats::addStat("Optimizations, Slice array skips due to size limit",
+                         m_statSliceElementSkips);
     }
 };
 

test_regress/t/t_constraint_global_arr_unsup.out

@@ -0,0 +1,26 @@
+%Error-UNSUPPORTED: t/t_constraint_global_arr_unsup.v:41:20: Unsupported: MEMBERSEL 'm_x' within a global constraint
+                                                           : ... note: In instance 't_constraint_global_arr_unsup'
+   41 |     m_mid.m_arr[0].m_x == 200;
+      |                    ^~~
+                    ... For error description see https://verilator.org/warn/UNSUPPORTED?v=latest
+%Error-UNSUPPORTED: t/t_constraint_global_arr_unsup.v:42:20: Unsupported: MEMBERSEL 'm_y' within a global constraint
+                                                           : ... note: In instance 't_constraint_global_arr_unsup'
+   42 |     m_mid.m_arr[0].m_y == 201;
+      |                    ^~~
+%Error-UNSUPPORTED: t/t_constraint_global_arr_unsup.v:47:18: Unsupported: MEMBERSEL 'm_obj' within a global constraint
+                                                           : ... note: In instance 't_constraint_global_arr_unsup'
+   47 |     m_mid_arr[0].m_obj.m_x == 300;
+      |                  ^~~~~
+%Error-UNSUPPORTED: t/t_constraint_global_arr_unsup.v:48:18: Unsupported: MEMBERSEL 'm_obj' within a global constraint
+                                                           : ... note: In instance 't_constraint_global_arr_unsup'
+   48 |     m_mid_arr[0].m_obj.m_y == 301;
+      |                  ^~~~~
+%Error-UNSUPPORTED: t/t_constraint_global_arr_unsup.v:53:18: Unsupported: MEMBERSEL 'm_arr' within a global constraint
+                                                           : ... note: In instance 't_constraint_global_arr_unsup'
+   53 |     m_mid_arr[1].m_arr[2].m_y == 400;
+      |                  ^~~~~
+%Error-UNSUPPORTED: t/t_constraint_global_arr_unsup.v:53:27: Unsupported: MEMBERSEL 'm_y' within a global constraint
+                                                           : ... note: In instance 't_constraint_global_arr_unsup'
+   53 |     m_mid_arr[1].m_arr[2].m_y == 400;
+      |                           ^~~
+%Error: Exiting due to

test_regress/t/t_constraint_global_arr_unsup.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.lint(fails=test.vlt_all, expect_filename=test.golden_filename)
+
+test.passes()

test_regress/t/t_constraint_global_arr_unsup.v

@@ -0,0 +1,86 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2025 by PlanV GmbH.
+// SPDX-License-Identifier: CC0-1.0
+
+/* verilator lint_off WIDTHTRUNC */
+class Inner;
+  rand int m_x;
+  rand int m_y;
+endclass
+
+class Middle;
+  rand Inner m_obj;
+  rand Inner m_arr[3];
+endclass
+
+class Outer;
+  rand Middle m_mid;
+  rand Middle m_mid_arr[2];
+
+  function new();
+    m_mid = new;
+    m_mid.m_obj = new;
+    foreach (m_mid.m_arr[i]) m_mid.m_arr[i] = new;
+    foreach (m_mid_arr[i]) begin
+      m_mid_arr[i] = new;
+      m_mid_arr[i].m_obj = new;
+      foreach (m_mid_arr[i].m_arr[j]) m_mid_arr[i].m_arr[j] = new;
+    end
+  endfunction
+
+  // Case 1: Simple nested member access (should work)
+  constraint c_simple {
+    m_mid.m_obj.m_x == 100;
+    m_mid.m_obj.m_y == 101;
+  }
+
+  // Case 2: Array indexing in the path (may not work)
+  constraint c_array_index {
+    m_mid.m_arr[0].m_x == 200;
+    m_mid.m_arr[0].m_y == 201;
+  }
+
+  // Case 3: Nested array indexing
+  constraint c_nested_array {
+    m_mid_arr[0].m_obj.m_x == 300;
+    m_mid_arr[0].m_obj.m_y == 301;
+  }
+
+  // Case 4: Multiple array indices
+  constraint c_multi_array {
+    m_mid_arr[1].m_arr[2].m_y == 400;
+  }
+endclass
+
+module t_constraint_global_arr_unsup;
+  initial begin
+    Outer o = new;
+    if (o.randomize()) begin
+      $display("Case 1 - Simple: mid.obj.x = %0d (expected 100)", o.m_mid.m_obj.m_x);
+      $display("Case 1 - Simple: mid.obj.y = %0d (expected 101)", o.m_mid.m_obj.m_y);
+      $display("Case 2 - Array[0]: mid.arr[0].x = %0d (expected 200)", o.m_mid.m_arr[0].m_x);
+      $display("Case 2 - Array[0]: mid.arr[0].y = %0d (expected 201)", o.m_mid.m_arr[0].m_y);
+      $display("Case 3 - Nested[0]: mid_arr[0].obj.x = %0d (expected 300)", o.m_mid_arr[0].m_obj.m_x);
+      $display("Case 3 - Nested[0]: mid_arr[0].obj.y = %0d (expected 301)", o.m_mid_arr[0].m_obj.m_y);
+      $display("Case 4 - Multi[1][2]: mid_arr[1].arr[2].y = %0d (expected 400)", o.m_mid_arr[1].m_arr[2].m_y);
+
+      // Check results
+      if (o.m_mid.m_obj.m_x == 100 && o.m_mid.m_obj.m_y == 101 &&
+          o.m_mid.m_arr[0].m_x == 200 && o.m_mid.m_arr[0].m_y == 201 &&
+          o.m_mid_arr[0].m_obj.m_x == 300 && o.m_mid_arr[0].m_obj.m_y == 301 &&
+          o.m_mid_arr[1].m_arr[2].m_y == 400) begin
+        $display("*-* All Finished *-*");
+        $finish;
+      end else begin
+        $display("*-* FAILED *-*");
+        $stop;
+      end
+    end else begin
+      $display("*-* FAILED: randomize() returned 0 *-*");
+      $stop;
+    end
+  end
+endmodule
+/* verilator lint_off WIDTHTRUNC */

test_regress/t/t_constraint_global_nested_unsup.out

@@ -0,0 +1,6 @@
+%Error-UNSUPPORTED: t/t_constraint_global_nested_unsup.v:9:14: Unsupported: One variable 'm_mid.m_inner' cannot have multiple global constraints
+                                                             : ... note: In instance 't'
+    9 |   constraint c_inner { m_val inside {[1:10]}; }
+      |              ^~~~~~~
+                    ... For error description see https://verilator.org/warn/UNSUPPORTED?v=latest
+%Error: Exiting due to

test_regress/t/t_constraint_global_nested_unsup.py

@@ -0,0 +1,16 @@
+#!/usr/bin/env python3
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2024 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.lint(fails=test.vlt_all, expect_filename=test.golden_filename)
+
+test.passes()

test_regress/t/t_constraint_global_nested_unsup.v

@@ -0,0 +1,51 @@
+// DESCRIPTION: Verilator: Test for unsupported multiple global constraints
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2025 by PlanV GmbH.
+// SPDX-License-Identifier: CC0-1.0
+
+
+class Inner;
+  rand int m_val;
+  constraint c_inner { m_val inside {[1:10]}; }
+  function new(); m_val = 0; endfunction
+endclass
+
+class Mid;
+  rand Inner m_inner;
+  rand int m_x;
+  // Mid has global constraint on m_inner.m_val
+  constraint c_mid_global {
+    m_x > m_inner.m_val;
+    m_x inside {[5:15]};
+  }
+  function new();
+    m_inner = new();
+    m_x = 0;
+  endfunction
+endclass
+
+class Top;
+  rand Mid m_mid;
+  rand int m_y;
+  // Top also has global constraint on m_mid.m_inner.m_val
+  constraint c_top_global {
+    m_y < m_mid.m_inner.m_val;
+    m_y inside {[1:5]};
+  }
+  function new();
+    m_mid = new();
+    m_y = 0;
+  endfunction
+endclass
+
+module t;
+  Top top;
+  /* verilator lint_off WIDTHTRUNC */
+  initial begin
+    top = new();
+    if (!top.randomize()) $stop;
+    $write("*-* All Finished *-*\n");
+    $finish;
+  end
+  /* verilator lint_off WIDTHTRUNC */
+endmodule

test_regress/t/t_constraint_global_random.py

@@ -0,0 +1,21 @@
+#!/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 not test.have_solver:
+    test.skip("No constraint solver installed")
+
+test.compile()
+
+test.execute()
+
+test.passes()

test_regress/t/t_constraint_global_random.v

@@ -0,0 +1,124 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2025 by PlanV GmbH.
+// SPDX-License-Identifier: CC0-1.0
+
+class Inner;
+  rand int m_val;
+  constraint c_local { m_val inside {[1:5]}; }
+
+  class NestedInner;
+    rand int nested_val;
+    constraint c_nested { nested_val inside {[1:3]}; }
+  endclass
+
+  rand NestedInner nested_obj;
+
+  function new();
+    m_val = 0;
+    nested_obj = new();
+  endfunction
+endclass
+
+class Mid;
+  int m_limit;
+  rand int m_x;
+  rand Inner m_inner;
+  constraint c_mid { m_x == m_limit; }
+  function new(int lim);
+    m_limit = lim;
+    m_inner = new();
+  endfunction
+endclass
+
+class Top;
+  rand Mid m_m1;
+  rand Mid m_m2;
+  rand int m_y;
+
+  constraint c_global {
+    m_m1.m_inner.m_val < m_m2.m_inner.m_val;
+    m_y > m_m1.m_x;
+    m_y < m_m2.m_x;
+    m_m1.m_inner.m_val + m_m2.m_inner.m_val < 8;
+    // Global constraint on nested class variable (3-level deep)
+    m_m1.m_inner.nested_obj.nested_val == 1;
+    m_m2.m_inner.nested_obj.nested_val == 3;
+  }
+
+  function new();
+    m_m1 = new(3);
+    m_m2 = new(5);
+    m_y = 0;
+  endfunction
+endclass
+
+// Second independent class with global constraints
+
+class AnotherTop;
+  rand Mid m_m3;
+  rand int m_z;
+
+  constraint c_another {
+    m_z < m_m3.m_x;
+  }
+
+  function new();
+    m_m3 = new(10);
+    m_z = 0;
+  endfunction
+endclass
+
+module t_constraint_global_random;
+  int success;
+  Top t;
+  AnotherTop t2;
+
+  initial begin
+    t = new();
+
+    // Test 1: Regular randomize() with global constraints
+    success = t.randomize();
+    if (success != 1) $stop;
+
+    if (t.m_m1.m_x != 3 || t.m_m2.m_x != 5) $stop;
+    if (t.m_m1.m_inner.m_val >= t.m_m2.m_inner.m_val) $stop;
+    if (t.m_y <= t.m_m1.m_x || t.m_y >= t.m_m2.m_x) $stop;
+    if (t.m_m1.m_inner.m_val + t.m_m2.m_inner.m_val >= 8) $stop;
+    if (t.m_m1.m_inner.m_val < 1 || t.m_m1.m_inner.m_val > 5 ||
+        t.m_m2.m_inner.m_val < 1 || t.m_m2.m_inner.m_val > 5) $stop;
+
+    // Verify nested class global constraints (3-level deep: Top -> Mid -> Inner -> NestedInner)
+    if (t.m_m1.m_inner.nested_obj.nested_val != 1) $stop;
+    if (t.m_m2.m_inner.nested_obj.nested_val != 3) $stop;
+
+    // Test 2: randomize() with inline constraint on global-constrained members
+    success = 0;
+    success = t.randomize() with {
+      m_m1.m_inner.m_val == 2;
+      m_m2.m_inner.m_val == 5;
+    };
+    if (success != 1) $stop;
+
+    // Verify inline constraints
+    if (t.m_m1.m_inner.m_val != 2) $stop;
+    if (t.m_m2.m_inner.m_val != 5) $stop;
+
+    // Verify global constraints still hold
+    if (t.m_m1.m_x != 3 || t.m_m2.m_x != 5) $stop;
+    if (t.m_m1.m_inner.m_val >= t.m_m2.m_inner.m_val) $stop;
+    if (t.m_y <= t.m_m1.m_x || t.m_y >= t.m_m2.m_x) $stop;
+    if (t.m_m1.m_inner.m_val + t.m_m2.m_inner.m_val >= 8) $stop;
+
+    // Test 3: Second independent class (tests m_clonedConstraints.clear() bug)
+    t2 = new();
+    success = t2.randomize();
+    if (success != 1) $stop;
+    if (t2.m_z >= t2.m_m3.m_x) $stop;
+    if (t2.m_m3.m_x != 10) $stop;
+
+    $write("*-* All Finished *-*\n");
+    $finish;
+  end
+endmodule

test_regress/t/t_opt_slice_element_limit.py

@@ -0,0 +1,20 @@
+#!/usr/bin/env python3
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2024 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.top_filename = "t/t_opt_slice_element_limit.v"
+
+test.compile(verilator_flags2=['--stats', '--fslice-element-limit', '10'])
+
+test.file_grep(test.stats, r'Optimizations, Slice array skips due to size limit\s+(\d+)', 4)
+
+test.passes()

test_regress/t/t_opt_slice_element_limit.v

@@ -0,0 +1,20 @@
+// DESCRIPTION: Verilator: Verilog Test module
+//
+// This file ONLY is placed under the Creative Commons Public Domain, for
+// any use, without warranty, 2024 by Wilson Snyder.
+// SPDX-License-Identifier: CC0-1.0
+
+module t (
+    input logic [7:0]  i1 [8],
+    input logic [7:0]  i2 [16],
+    input logic [7:0]  i3 [512],
+    output logic [7:0] o1 [8],
+    output logic [7:0]  o2 [16],
+    output logic [7:0] o3 [256]
+   );
+
+   initial begin
+      $write("*-* All Finished *-*\n");
+      $finish;
+   end
+endmodule

test_regress/t/t_opt_slice_element_limit_allow_all.py

@@ -0,0 +1,20 @@
+#!/usr/bin/env python3
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2024 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.top_filename = "t/t_opt_slice_element_limit.v"
+
+test.compile(verilator_flags2=['--stats', '--fslice-element-limit', '0'])
+
+test.file_grep(test.stats, r'Optimizations, Slice array skips due to size limit\s+(\d+)', 0)
+
+test.passes()

test_regress/t/t_opt_slice_element_limit_bad.out

@@ -0,0 +1,2 @@
+%Error: --fslice-element-limit must be >= 0: -100
+        ... See the manual at https://verilator.org/verilator_doc.html?v=5.043 for more assistance.

test_regress/t/t_opt_slice_element_limit_bad.py

@@ -0,0 +1,21 @@
+#!/usr/bin/env python3
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2024 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('linter')
+
+test.top_filename = "t/t_opt_slice_element_limit.v"
+test.golden_filename = "t/t_opt_slice_element_limit_bad.out"
+
+test.lint(fails=True,
+          verilator_flags2=['--stats', '--fslice-element-limit', '-100'],
+          except_filename=test.golden_filename)
+
+test.passes()

test_regress/t/t_opt_slice_element_limit_default.py

@@ -0,0 +1,20 @@
+#!/usr/bin/env python3
+# DESCRIPTION: Verilator: Verilog Test driver/expect definition
+#
+# Copyright 2024 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.top_filename = "t/t_opt_slice_element_limit.v"
+
+test.compile(verilator_flags2=['--stats'])
+
+test.file_grep(test.stats, r'Optimizations, Slice array skips due to size limit\s+(\d+)', 1)
+
+test.passes()

test_regress/t/t_randomize_method_types_unsup.out

@@ -7,9 +7,6 @@
                                                                : ... note: In instance 't'
    27 |       q.size < 5;
       |         ^~~~
-%Warning-CONSTRAINTIGN: t/t_randomize_method_types_unsup.v:31:10: Global constraints ignored (unsupported)
-   31 |      foo.x < y;
-      |          ^
 %Error-UNSUPPORTED: t/t_randomize_method_types_unsup.v:15:13: Unsupported: random member variable with the type of the containing class
                                                             : ... note: In instance 't'
    15 |    rand Cls cls;