diff options
Diffstat (limited to 'llvm/lib/Analysis')
-rw-r--r-- | llvm/lib/Analysis/InstructionSimplify.cpp | 16 | ||||
-rw-r--r-- | llvm/lib/Analysis/ValueTracking.cpp | 10 |
2 files changed, 26 insertions, 0 deletions
diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp index 4cb3fdb..42e4433 100644 --- a/llvm/lib/Analysis/InstructionSimplify.cpp +++ b/llvm/lib/Analysis/InstructionSimplify.cpp @@ -4080,6 +4080,22 @@ static Value *simplifySelectWithICmpCond(Value *CondVal, Value *TrueVal, std::swap(TrueVal, FalseVal); } + // Check for integer min/max with a limit constant: + // X > MIN_INT ? X : MIN_INT --> X + // X < MAX_INT ? X : MAX_INT --> X + if (TrueVal->getType()->isIntOrIntVectorTy()) { + Value *X, *Y; + SelectPatternFlavor SPF = + matchDecomposedSelectPattern(cast<ICmpInst>(CondVal), TrueVal, FalseVal, + X, Y).Flavor; + if (SelectPatternResult::isMinOrMax(SPF) && Pred == getMinMaxPred(SPF)) { + APInt LimitC = getMinMaxLimit(getInverseMinMaxFlavor(SPF), + X->getType()->getScalarSizeInBits()); + if (match(Y, m_SpecificInt(LimitC))) + return X; + } + } + if (Pred == ICmpInst::ICMP_EQ && match(CmpRHS, m_Zero())) { Value *X; const APInt *Y; diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp index b146f07..1e63fc0 100644 --- a/llvm/lib/Analysis/ValueTracking.cpp +++ b/llvm/lib/Analysis/ValueTracking.cpp @@ -6253,6 +6253,16 @@ CmpInst::Predicate llvm::getInverseMinMaxPred(SelectPatternFlavor SPF) { return getMinMaxPred(getInverseMinMaxFlavor(SPF)); } +APInt llvm::getMinMaxLimit(SelectPatternFlavor SPF, unsigned BitWidth) { + switch (SPF) { + case SPF_SMAX: return APInt::getSignedMaxValue(BitWidth); + case SPF_SMIN: return APInt::getSignedMinValue(BitWidth); + case SPF_UMAX: return APInt::getMaxValue(BitWidth); + case SPF_UMIN: return APInt::getMinValue(BitWidth); + default: llvm_unreachable("Unexpected flavor"); + } +} + std::pair<Intrinsic::ID, bool> llvm::canConvertToMinOrMaxIntrinsic(ArrayRef<Value *> VL) { // Check if VL contains select instructions that can be folded into a min/max |