luke/verilator
1
0
Fork 0
mirror of https://github.com/verilator/verilator.git synced 2026-09-03 08:24:31 +02:00
Code Issues Packages Projects Releases Wiki Activity

Fix scoped randomize with array members under rand_mode (#7877)

Browse Source
This commit is contained in:
Yilou Wang
2026-07-11 20:28:49 -07:00
committed by GitHub
parent ec124a0905
commit 7ca78a75e7
4 changed files with 379 additions and 13 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/V3Randomize.cpp
+80 -9
View File
@@ -631,6 +631,8 @@ class RandomizeMarkVisitor final : public VNVisitor {
}
handleRandomizeArgument(argp->exprp(), fromVarp, false);
}
// Re-mark members after the class became inline-randomized above.
if (classp && classp->user1() == IS_RANDOMIZED_INLINE) markMembers(classp);
}
void visit(AstConstraintUnique* nodep) override {
VL_RESTORER(m_stmtp);
@@ -900,13 +902,13 @@ class ConstraintExprVisitor final : public VNVisitor {
handle.relink(getConstFormat(nodep));
return true;
}
void editSMT(AstNodeExpr* nodep, AstNodeExpr* lhsp = nullptr, AstNodeExpr* rhsp = nullptr,
AstNodeExpr* thsp = nullptr) {
AstSFormatF* editSMT(AstNodeExpr* nodep, AstNodeExpr* lhsp = nullptr,
AstNodeExpr* rhsp = nullptr, AstNodeExpr* thsp = nullptr) {
// Replace incomputable (result-dependent) expression with SMT expression
std::string smtExpr = nodep->emitSMT(); // Might need child width (AstExtend)
if (smtExpr == "") {
nodep->v3warn(E_UNSUPPORTED, "Unsupported expression inside constraint");
return;
return nullptr;
}
if (lhsp)
@@ -957,6 +959,7 @@ class ConstraintExprVisitor final : public VNVisitor {
}
nodep->replaceWith(newp);
VL_DO_DANGLING(pushDeletep(nodep), nodep);
return newp;
}
AstNodeExpr* editSingle(FileLine* fl, AstNode* itemsp) {
@@ -1897,13 +1900,15 @@ class ConstraintExprVisitor final : public VNVisitor {
void visit(AstAssocSel* nodep) override {
if (editFormat(nodep)) return;
FileLine* const fl = nodep->fileline();
// Adaptive formatting and type handling for associative array keys
// Keep a pre-edit clone for the rand_mode hoist below.
AstNodeExpr* const origp = nodep->cloneTree(false);
AstSFormatF* newp = nullptr;
if (VN_IS(nodep->bitp(), VarRef) && VN_AS(nodep->bitp(), VarRef)->isString()) {
VNRelinker handle;
AstNodeExpr* const idxp = new AstSFormatF{fl, (m_structSel ? "%32x" : "#x%32x"), false,
nodep->bitp()->unlinkFrBack(&handle)};
handle.relink(idxp);
editSMT(nodep, nodep->fromp(), idxp);
newp = editSMT(nodep, nodep->fromp(), idxp);
} else if (VN_IS(nodep->bitp(), CvtPackString)
&& VN_IS(nodep->bitp()->dtypep(), BasicDType)) {
AstCvtPackString* const stringp = VN_AS(nodep->bitp(), CvtPackString);
@@ -1918,7 +1923,7 @@ class ConstraintExprVisitor final : public VNVisitor {
AstNodeExpr* const idxp = new AstSFormatF{fl, (m_structSel ? "%32x" : "#x%32x"), false,
stringp->lhsp()->unlinkFrBack(&handle)};
handle.relink(idxp);
editSMT(nodep, nodep->fromp(), idxp);
newp = editSMT(nodep, nodep->fromp(), idxp);
} else {
if (VN_IS(nodep->bitp()->dtypep(), BasicDType)
|| (VN_IS(nodep->bitp()->dtypep(), StructDType)
@@ -1940,13 +1945,16 @@ class ConstraintExprVisitor final : public VNVisitor {
AstNodeExpr* const idxp
= new AstSFormatF{fl, fmt, false, nodep->bitp()->unlinkFrBack(&handle)};
handle.relink(idxp);
editSMT(nodep, nodep->fromp(), idxp);
newp = editSMT(nodep, nodep->fromp(), idxp);
} else {
nodep->bitp()->v3error(
"Illegal non-integral expression or subexpression in random constraint."
" (IEEE 1800-2023 18.3)");
}
}
if (!newp || !hoistRandModeOverSelect(newp, origp)) {
VL_DO_DANGLING(origp->deleteTree(), origp);
}
}
void visit(AstArraySel* nodep) override {
if (editFormat(nodep)) return;
@@ -1971,13 +1979,65 @@ class ConstraintExprVisitor final : public VNVisitor {
handle.relink(indexp);
editSMT(nodep, nodep->fromp(), indexp);
} else {
// Index is constant or non-rand -- format as hex literal
// Index is constant or non-rand -- format as hex literal.
// Keep a pre-edit clone for the rand_mode hoist below.
AstNodeExpr* const origp = nodep->cloneTree(false);
AstNodeExpr* const indexp
= new AstSFormatF{fl, "#x%8x", false, nodep->bitp()->unlinkFrBack(&handle)};
handle.relink(indexp);
editSMT(nodep, nodep->fromp(), indexp);
AstSFormatF* const newp = editSMT(nodep, nodep->fromp(), indexp);
if (!newp || !hoistRandModeOverSelect(newp, origp)) {
VL_DO_DANGLING(origp->deleteTree(), origp);
}
}
}
// True iff exprp is an ARRAY_AT read of a class's own instance mode array.
static bool isRandModeGate(const AstNodeExpr* exprp) {
const AstCMethodHard* const atp = VN_CAST(exprp, CMethodHard);
if (!atp || atp->method() != VCMethod::ARRAY_AT) return false;
const AstVar* varp = nullptr;
if (const AstVarRef* const refp = VN_CAST(atp->fromp(), VarRef)) {
varp = refp->varp();
} else if (const AstMemberSel* const mselp = VN_CAST(atp->fromp(), MemberSel)) {
varp = mselp->varp();
}
if (!varp) return false;
const AstClass* const classp = VN_CAST(varp->user2p(), Class);
return classp && classp->user2p() == varp;
}
// Lift a rand_mode Cond above the (select ...) chain of a frozen array element.
bool hoistRandModeOverSelect(AstSFormatF* newp, AstNodeExpr* origp) {
// Only for selects yielding a non-array element (full chains)
if (VN_IS(origp->dtypep()->skipRefp(), UnpackArrayDType)) return false;
// Walk nested "(select %s %s)" frames down to a mode-gating AstCond
std::vector<AstSFormatF*> frames;
AstCond* modeCondp = nullptr;
for (AstSFormatF* curp = newp; curp && curp->name() == "(select %s %s)";) {
AstNodeExpr* const firstp = curp->exprsp();
frames.push_back(curp);
if (AstCond* const condp = VN_CAST(firstp, Cond)) {
if (isRandModeGate(condp->condp())) modeCondp = condp;
break;
}
curp = VN_CAST(firstp, SFormatF);
}
if (!modeCondp) return false;
FileLine* const fl = newp->fileline();
AstNodeExpr* const modep = modeCondp->condp()->unlinkFrBack();
AstNodeExpr* activep = modeCondp->thenp()->unlinkFrBack();
// Rebuild the select chain text around the SMT name, innermost first
for (auto it = frames.rbegin(); it != frames.rend(); ++it) {
AstNodeExpr* const idxFmtp = VN_AS((*it)->exprsp()->nextp(), NodeExpr);
idxFmtp->unlinkFrBack();
activep
= new AstSFormatF{fl, "(select %s %s)", false, AstNode::addNext(activep, idxFmtp)};
}
AstCond* const hoistp = new AstCond{fl, modep, activep, getConstFormat(origp)};
hoistp->user1(true); // Mark as formatted
newp->replaceWith(hoistp);
VL_DO_DANGLING(pushDeletep(newp), newp);
return true;
}
void visit(AstMemberSel* nodep) override {
// Check if rootVar is globalConstrained
if (nodep->varp()->rand().isRandomizable() && nodep->fromp()) {
@@ -2367,6 +2427,14 @@ class ConstraintExprVisitor final : public VNVisitor {
FileLine* const fl = nodep->fileline();
if (nodep->method() == VCMethod::ARRAY_AT && nodep->fromp()->user1()) {
// Queue/dynamic element: pre-edit clone for the rand_mode hoist, non-rand index only.
bool indexIsRand = false;
if (nodep->pinsp()) {
nodep->pinsp()->foreach([&](const AstNodeVarRef* vrefp) {
if (vrefp->varp()->rand().isRandomizable()) indexIsRand = true;
});
}
AstNodeExpr* const origp = indexIsRand ? nullptr : nodep->cloneTree(false);
iterateChildren(nodep);
AstNodeExpr* pinp = nodep->pinsp()->unlinkFrBack();
if (VN_IS(pinp, SFormatF) && m_structSel) VN_AS(pinp, SFormatF)->name("%x");
@@ -2378,6 +2446,9 @@ class ConstraintExprVisitor final : public VNVisitor {
newp = new AstSFormatF{fl, "(select %s %s)", false, argsp};
nodep->replaceWith(newp);
VL_DO_DANGLING(nodep->deleteTree(), nodep);
if (origp && !hoistRandModeOverSelect(newp, origp)) {
VL_DO_DANGLING(origp->deleteTree(), origp);
}
return;
}