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[SCEV] Use m_scev_Mul in a few more places. (NFC) #163364

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Merged
merged 2 commits into from
Oct 16, 2025
Merged

[SCEV] Use m_scev_Mul in a few more places. (NFC) #163364

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e9bf4f5
[SCEV] Use m_scev_Mul in a few more places. (NFC)
fhahn Oct 14, 2025
e5092e9
Merge branch 'main' into scev-use-more-mul-urem-pattern
fhahn Oct 16, 2025
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14 changes: 7 additions & 7 deletions llvm/include/llvm/Analysis/ScalarEvolutionPatternMatch.h
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Original file line number Diff line number Diff line change
Expand Up @@ -95,6 +95,10 @@ inline bind_ty<const SCEVAddExpr> m_scev_Add(const SCEVAddExpr *&V) {
return V;
}

inline bind_ty<const SCEVMulExpr> m_scev_Mul(const SCEVMulExpr *&V) {
return V;
}

/// Match a specified const SCEV *.
struct specificscev_ty {
const SCEV *Expr;
Expand Down Expand Up @@ -284,14 +288,10 @@ template <typename Op0_t, typename Op1_t> struct SCEVURem_match {
<< SE.getTypeSizeInBits(TruncTy));
return Op0.match(LHS) && Op1.match(RHS);
}
const auto *Add = dyn_cast<SCEVAddExpr>(Expr);
if (Add == nullptr || Add->getNumOperands() != 2)
return false;

const SCEV *A = Add->getOperand(1);
const auto *Mul = dyn_cast<SCEVMulExpr>(Add->getOperand(0));

if (Mul == nullptr)
const SCEV *A;
const SCEVMulExpr *Mul;
if (!SCEVPatternMatch::match(Expr, m_scev_Add(m_scev_Mul(Mul), m_SCEV(A))))
return false;

const auto MatchURemWithDivisor = [&](const SCEV *B) {
Expand Down
27 changes: 10 additions & 17 deletions llvm/lib/Analysis/ScalarEvolution.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -4623,17 +4623,11 @@ const SCEV *ScalarEvolution::getNegativeSCEV(const SCEV *V,

/// If Expr computes ~A, return A else return nullptr
static const SCEV *MatchNotExpr(const SCEV *Expr) {
const SCEVAddExpr *Add = dyn_cast<SCEVAddExpr>(Expr);
if (!Add || Add->getNumOperands() != 2 ||
!Add->getOperand(0)->isAllOnesValue())
return nullptr;

const SCEVMulExpr *AddRHS = dyn_cast<SCEVMulExpr>(Add->getOperand(1));
if (!AddRHS || AddRHS->getNumOperands() != 2 ||
!AddRHS->getOperand(0)->isAllOnesValue())
return nullptr;

return AddRHS->getOperand(1);
const SCEV *MulOp;
if (match(Expr, m_scev_Add(m_scev_AllOnes(),
m_scev_Mul(m_scev_AllOnes(), m_SCEV(MulOp)))))
return MulOp;
return nullptr;
}

/// Return a SCEV corresponding to ~V = -1-V
Expand Down Expand Up @@ -12220,12 +12214,11 @@ ScalarEvolution::computeConstantDifference(const SCEV *More, const SCEV *Less) {
// Try to match a common constant multiply.
auto MatchConstMul =
[](const SCEV *S) -> std::optional<std::pair<const SCEV *, APInt>> {
auto *M = dyn_cast<SCEVMulExpr>(S);
if (!M || M->getNumOperands() != 2 ||
!isa<SCEVConstant>(M->getOperand(0)))
return std::nullopt;
return {
{M->getOperand(1), cast<SCEVConstant>(M->getOperand(0))->getAPInt()}};
const APInt *C;
const SCEV *Op;
if (match(S, m_scev_Mul(m_scev_APInt(C), m_SCEV(Op))))
return {{Op, *C}};
return std::nullopt;
};
if (auto MatchedMore = MatchConstMul(More)) {
if (auto MatchedLess = MatchConstMul(Less)) {
Expand Down
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