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-rw-r--r--lib/VMCore/ConstantFold.cpp8
1 files changed, 5 insertions, 3 deletions
diff --git a/lib/VMCore/ConstantFold.cpp b/lib/VMCore/ConstantFold.cpp
index 7f713d15c6..2449739aaf 100644
--- a/lib/VMCore/ConstantFold.cpp
+++ b/lib/VMCore/ConstantFold.cpp
@@ -1839,14 +1839,16 @@ Constant *llvm::ConstantFoldCompareInstruction(LLVMContext &Context,
}
}
- if (!isa<ConstantExpr>(C1) && isa<ConstantExpr>(C2)) {
+ if ((!isa<ConstantExpr>(C1) && isa<ConstantExpr>(C2)) ||
+ (C1->isNullValue() && !C2->isNullValue())) {
// If C2 is a constant expr and C1 isn't, flip them around and fold the
// other way if possible.
+ // Also, if C1 is null and C2 isn't, flip them around.
switch (pred) {
case ICmpInst::ICMP_EQ:
case ICmpInst::ICMP_NE:
// No change of predicate required.
- return ConstantFoldCompareInstruction(Context, pred, C2, C1);
+ return ConstantExpr::getICmp(pred, C2, C1);
case ICmpInst::ICMP_ULT:
case ICmpInst::ICMP_SLT:
@@ -1858,7 +1860,7 @@ Constant *llvm::ConstantFoldCompareInstruction(LLVMContext &Context,
case ICmpInst::ICMP_SGE:
// Change the predicate as necessary to swap the operands.
pred = ICmpInst::getSwappedPredicate((ICmpInst::Predicate)pred);
- return ConstantFoldCompareInstruction(Context, pred, C2, C1);
+ return ConstantExpr::getICmp(pred, C2, C1);
default: // These predicates cannot be flopped around.
break;