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path: root/lib/Transforms/InstCombine/InstCombineSelect.cpp
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Diffstat (limited to 'lib/Transforms/InstCombine/InstCombineSelect.cpp')
-rw-r--r--lib/Transforms/InstCombine/InstCombineSelect.cpp9
1 files changed, 6 insertions, 3 deletions
diff --git a/lib/Transforms/InstCombine/InstCombineSelect.cpp b/lib/Transforms/InstCombine/InstCombineSelect.cpp
index 82ce31128c..c15378bc74 100644
--- a/lib/Transforms/InstCombine/InstCombineSelect.cpp
+++ b/lib/Transforms/InstCombine/InstCombineSelect.cpp
@@ -195,7 +195,10 @@ static bool isSelect01(Constant *C1, Constant *C2) {
ConstantInt *C2I = dyn_cast<ConstantInt>(C2);
if (!C2I)
return false;
- return (C1I->isZero() || C1I->isOne()) && (C2I->isZero() || C2I->isOne());
+ if (!C1I->isZero() && !C2I->isZero()) // One side must be zero.
+ return false;
+ return C1I->isOne() || C1I->isAllOnesValue() ||
+ C2I->isOne() || C2I->isAllOnesValue();
}
/// FoldSelectIntoOp - Try fold the select into one of the operands to
@@ -219,7 +222,7 @@ Instruction *InstCombiner::FoldSelectIntoOp(SelectInst &SI, Value *TrueVal,
Constant *C = GetSelectFoldableConstant(TVI);
Value *OOp = TVI->getOperand(2-OpToFold);
// Avoid creating select between 2 constants unless it's selecting
- // between 0 and 1.
+ // between 0, 1 and -1.
if (!isa<Constant>(OOp) || isSelect01(C, cast<Constant>(OOp))) {
Instruction *NewSel = SelectInst::Create(SI.getCondition(), OOp, C);
InsertNewInstBefore(NewSel, SI);
@@ -248,7 +251,7 @@ Instruction *InstCombiner::FoldSelectIntoOp(SelectInst &SI, Value *TrueVal,
Constant *C = GetSelectFoldableConstant(FVI);
Value *OOp = FVI->getOperand(2-OpToFold);
// Avoid creating select between 2 constants unless it's selecting
- // between 0 and 1.
+ // between 0, 1 and -1.
if (!isa<Constant>(OOp) || isSelect01(C, cast<Constant>(OOp))) {
Instruction *NewSel = SelectInst::Create(SI.getCondition(), C, OOp);
InsertNewInstBefore(NewSel, SI);