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-rw-r--r--llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp26
1 files changed, 12 insertions, 14 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
index cfae47fbd7e..6121b80f23b 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
@@ -424,24 +424,22 @@ static bool adjustMinMax(SelectInst &Sel, ICmpInst &Cmp) {
Value *FalseVal = Sel.getFalseValue();
// We may move or edit the compare, so make sure the select is the only user.
- if (!Cmp.hasOneUse())
+ const APInt *CmpC;
+ if (!Cmp.hasOneUse() || !match(CmpRHS, m_APInt(CmpC)))
return false;
- // FIXME: Use m_APInt to allow vector folds.
- auto *CI = dyn_cast<ConstantInt>(CmpRHS);
- if (!CI)
- return false;
-
- // These transformations only work for selects over integers.
- IntegerType *SelectTy = dyn_cast<IntegerType>(Sel.getType());
- if (!SelectTy)
+ // These transforms only work for selects of integers or vector selects of
+ // integer vectors.
+ Type *SelTy = Sel.getType();
+ auto *SelEltTy = dyn_cast<IntegerType>(SelTy->getScalarType());
+ if (!SelEltTy || SelTy->isVectorTy() != Cmp.getType()->isVectorTy())
return false;
Constant *AdjustedRHS;
if (Pred == ICmpInst::ICMP_UGT || Pred == ICmpInst::ICMP_SGT)
- AdjustedRHS = ConstantInt::get(CI->getContext(), CI->getValue() + 1);
+ AdjustedRHS = ConstantInt::get(CmpRHS->getType(), *CmpC + 1);
else if (Pred == ICmpInst::ICMP_ULT || Pred == ICmpInst::ICMP_SLT)
- AdjustedRHS = ConstantInt::get(CI->getContext(), CI->getValue() - 1);
+ AdjustedRHS = ConstantInt::get(CmpRHS->getType(), *CmpC - 1);
else
return false;
@@ -454,8 +452,8 @@ static bool adjustMinMax(SelectInst &Sel, ICmpInst &Cmp) {
// Types do not match. Instead of calculating this with mixed types, promote
// all to the larger type. This enables scalar evolution to analyze this
// expression.
- else if (CmpRHS->getType()->getScalarSizeInBits() < SelectTy->getBitWidth()) {
- Constant *SextRHS = ConstantExpr::getSExt(AdjustedRHS, SelectTy);
+ else if (CmpRHS->getType()->getScalarSizeInBits() < SelEltTy->getBitWidth()) {
+ Constant *SextRHS = ConstantExpr::getSExt(AdjustedRHS, SelTy);
// X = sext x; x >s c ? X : C+1 --> X = sext x; X <s C+1 ? C+1 : X
// X = sext x; x <s c ? X : C-1 --> X = sext x; X >s C-1 ? C-1 : X
@@ -469,7 +467,7 @@ static bool adjustMinMax(SelectInst &Sel, ICmpInst &Cmp) {
CmpLHS = FalseVal;
AdjustedRHS = SextRHS;
} else if (Cmp.isUnsigned()) {
- Constant *ZextRHS = ConstantExpr::getZExt(AdjustedRHS, SelectTy);
+ Constant *ZextRHS = ConstantExpr::getZExt(AdjustedRHS, SelTy);
// X = zext x; x >u c ? X : C+1 --> X = zext x; X <u C+1 ? C+1 : X
// X = zext x; x <u c ? X : C-1 --> X = zext x; X >u C-1 ? C-1 : X
// zext + signed compare cannot be changed:
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