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Fix memory leak in V3Const::ifMergeAdjacent (#6449)

This commit is contained in:
Geza Lore 2025-09-18 00:45:28 +02:00 committed by GitHub
parent 57c82b9c34
commit ed6687359b
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GPG Key ID: B5690EEEBB952194
1 changed files with 22 additions and 22 deletions
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44
src/V3Const.cpp
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@ -1528,39 +1528,39 @@ class ConstVisitor final : public VNVisitor {
const int rend = (rstart->toSInt() + rhsp->widthConst());
return (rend == lstart->toSInt());
}
bool ifMergeAdjacent(AstNodeExpr* lhsp, AstNodeExpr* rhsp) {
bool ifMergeAdjacent(const AstNodeExpr* lhsp, const AstNodeExpr* rhsp) {
// called by concatmergeable to determine if {lhsp, rhsp} make sense
if (!v3Global.opt.fAssemble()) return false; // opt disabled
// two same varref
if (operandsSame(lhsp, rhsp)) return true;
const AstSel* lselp = VN_CAST(lhsp, Sel);
const AstSel* rselp = VN_CAST(rhsp, Sel);
// a[i:0] a
if (lselp && !rselp && rhsp->sameGateTree(lselp->fromp()))
rselp = new AstSel{rhsp->fileline(), rhsp->cloneTreePure(false), 0, rhsp->width()};
const AstSel* const lselp = VN_CAST(lhsp, Sel);
const AstSel* const rselp = VN_CAST(rhsp, Sel);
if (!lselp && !rselp) return false;
if (lselp && !VN_IS(lselp->lsbp(), Const)) return false;
if (rselp && !VN_IS(rselp->lsbp(), Const)) return false;
// a[i:j] {a[j-1:k], b}
if (lselp && !rselp && VN_IS(rhsp, Concat))
return ifMergeAdjacent(lhsp, VN_CAST(rhsp, Concat)->lhsp());
// a a[msb:j]
if (rselp && !lselp && lhsp->sameGateTree(rselp->fromp()))
lselp = new AstSel{lhsp->fileline(), lhsp->cloneTreePure(false), 0, lhsp->width()};
return ifMergeAdjacent(lhsp, VN_AS(rhsp, Concat)->lhsp());
// {b, a[j:k]} a[k-1:i]
if (rselp && !lselp && VN_IS(lhsp, Concat))
return ifMergeAdjacent(VN_CAST(lhsp, Concat)->rhsp(), rhsp);
if (!lselp || !rselp) return false;
// a[a:b] a[b-1:c] are adjacent
const AstNode* const lfromp = lselp->fromp();
const AstNode* const rfromp = rselp->fromp();
return ifMergeAdjacent(VN_AS(lhsp, Concat)->rhsp(), rhsp);
// a a[msb:j]
const AstNodeExpr* const lfromp = lselp ? lselp->fromp()
: lhsp->sameGateTree(rselp->fromp()) ? lhsp
: nullptr;
// a[i:0] a
const AstNodeExpr* const rfromp = rselp ? rselp->fromp()
: rhsp->sameGateTree(lselp->fromp()) ? rhsp
: nullptr;
if (!lfromp || !rfromp || !lfromp->sameGateTree(rfromp)) return false;
const AstConst* const lstart = VN_CAST(lselp->lsbp(), Const);
const AstConst* const rstart = VN_CAST(rselp->lsbp(), Const);
if (!lstart || !rstart) return false; // too complicated
const int rend = (rstart->toSInt() + rselp->widthConst());
const int32_t lstart = lselp ? lselp->lsbConst() : 0;
const int32_t rstart = rselp ? rselp->lsbConst() : 0;
const int32_t rend = rstart + (rselp ? rselp->widthConst() : rhsp->width());
// a[i:j] a[j-1:k]
if (rend == lstart->toSInt()) return true;
if (rend == lstart) return true;
// a[i:0] a[msb:j]
if (rend == rfromp->width() && lstart->toSInt() == 0) return true;
if (rend == rfromp->width() && lstart == 0) return true;
return false;
}
bool concatMergeable(const AstNodeExpr* lhsp, const AstNodeExpr* rhsp, unsigned depth) {