Skip to content

[SCEV] Improve code using DenseMap::lookup (NFC) #147507

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Jul 8, 2025
Merged

[SCEV] Improve code using DenseMap::lookup (NFC) #147507

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
38 changes: 17 additions & 21 deletions llvm/lib/Analysis/ScalarEvolution.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1559,9 +1559,8 @@ ScalarEvolution::getZeroExtendExpr(const SCEV *Op, Type *Ty, unsigned Depth) {
Ty = getEffectiveSCEVType(Ty);

FoldID ID(scZeroExtend, Op, Ty);
auto Iter = FoldCache.find(ID);
if (Iter != FoldCache.end())
return Iter->second;
if (const SCEV *S = FoldCache.lookup(ID))
return S;

const SCEV *S = getZeroExtendExprImpl(Op, Ty, Depth);
if (!isa<SCEVZeroExtendExpr>(S))
Expand Down Expand Up @@ -1894,9 +1893,8 @@ ScalarEvolution::getSignExtendExpr(const SCEV *Op, Type *Ty, unsigned Depth) {
Ty = getEffectiveSCEVType(Ty);

FoldID ID(scSignExtend, Op, Ty);
auto Iter = FoldCache.find(ID);
if (Iter != FoldCache.end())
return Iter->second;
if (const SCEV *S = FoldCache.lookup(ID))
return S;

const SCEV *S = getSignExtendExprImpl(Op, Ty, Depth);
if (!isa<SCEVSignExtendExpr>(S))
Expand Down Expand Up @@ -14521,15 +14519,15 @@ void ScalarEvolution::verify() const {

for (const auto &KV : ExprValueMap) {
for (Value *V : KV.second) {
auto It = ValueExprMap.find_as(V);
if (It == ValueExprMap.end()) {
const SCEV *S = ValueExprMap.lookup(V);
if (!S) {
dbgs() << "Value " << *V
<< " is in ExprValueMap but not in ValueExprMap\n";
std::abort();
}
if (It->second != KV.first) {
dbgs() << "Value " << *V << " mapped to " << *It->second
<< " rather than " << *KV.first << "\n";
if (S != KV.first) {
dbgs() << "Value " << *V << " mapped to " << *S << " rather than "
<< *KV.first << "\n";
std::abort();
}
}
Expand Down Expand Up @@ -14648,15 +14646,15 @@ void ScalarEvolution::verify() const {
}
for (auto [Expr, IDs] : FoldCacheUser) {
for (auto &FoldID : IDs) {
auto I = FoldCache.find(FoldID);
if (I == FoldCache.end()) {
const SCEV *S = FoldCache.lookup(FoldID);
if (!S) {
dbgs() << "Missing entry in FoldCache for expression " << *Expr
<< "!\n";
std::abort();
}
if (I->second != Expr) {
dbgs() << "Entry in FoldCache doesn't match FoldCacheUser: "
<< *I->second << " != " << *Expr << "!\n";
if (S != Expr) {
dbgs() << "Entry in FoldCache doesn't match FoldCacheUser: " << *S
<< " != " << *Expr << "!\n";
std::abort();
}
}
Expand Down Expand Up @@ -15624,8 +15622,7 @@ void ScalarEvolution::LoopGuards::collectFromBlock(
// existing rewrite because we want to chain further rewrites onto the
// already rewritten value. Otherwise returns \p S.
auto GetMaybeRewritten = [&](const SCEV *S) {
auto I = RewriteMap.find(S);
return I != RewriteMap.end() ? I->second : S;
return RewriteMap.lookup_or(S, S);
};

// Check for the SCEV expression (A /u B) * B while B is a constant, inside
Expand Down Expand Up @@ -15928,9 +15925,8 @@ const SCEV *ScalarEvolution::LoopGuards::rewrite(const SCEV *Expr) const {
Bitwidth > Op->getType()->getScalarSizeInBits()) {
Type *NarrowTy = IntegerType::get(SE.getContext(), Bitwidth);
auto *NarrowExt = SE.getZeroExtendExpr(Op, NarrowTy);
auto I = Map.find(NarrowExt);
if (I != Map.end())
return SE.getZeroExtendExpr(I->second, Ty);
if (const SCEV *S = Map.lookup(NarrowExt))
return SE.getZeroExtendExpr(S, Ty);
Bitwidth = Bitwidth / 2;
}

Expand Down
Loading