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| author | Duncan P. N. Exon Smith <dexonsmith@apple.com> | 2013-12-06 21:48:36 +0000 |
|---|---|---|
| committer | Duncan P. N. Exon Smith <dexonsmith@apple.com> | 2013-12-06 21:48:36 +0000 |
| commit | 42883d0ac4388c12c856225760fe591a361db7bc (patch) | |
| tree | d1b34bcd6a84136d12e6b42efe7c8df97b76dc59 /lib/Transforms/InstCombine | |
| parent | 92b10e5f858b5554a569007eeaf7a48bad622aea (diff) | |
| download | llvm-42883d0ac4388c12c856225760fe591a361db7bc.tar.gz llvm-42883d0ac4388c12c856225760fe591a361db7bc.tar.bz2 llvm-42883d0ac4388c12c856225760fe591a361db7bc.tar.xz | |
Don't use isNullValue to evaluate ConstantExpr
ConstantExpr can evaluate to false even when isNullValue gives false.
Fixes PR18143.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196611 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Transforms/InstCombine')
| -rw-r--r-- | lib/Transforms/InstCombine/InstructionCombining.cpp | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/lib/Transforms/InstCombine/InstructionCombining.cpp b/lib/Transforms/InstCombine/InstructionCombining.cpp index 27f1a3eb69..191a101e0a 100644 --- a/lib/Transforms/InstCombine/InstructionCombining.cpp +++ b/lib/Transforms/InstCombine/InstructionCombining.cpp @@ -699,7 +699,10 @@ Instruction *InstCombiner::FoldOpIntoPhi(Instruction &I) { Value *TrueVInPred = TrueV->DoPHITranslation(PhiTransBB, ThisBB); Value *FalseVInPred = FalseV->DoPHITranslation(PhiTransBB, ThisBB); Value *InV = 0; - if (Constant *InC = dyn_cast<Constant>(PN->getIncomingValue(i))) + // Beware of ConstantExpr: it may eventually evaluate to getNullValue, + // even if currently isNullValue gives false. + Constant *InC = dyn_cast<Constant>(PN->getIncomingValue(i)); + if (InC && !isa<ConstantExpr>(InC)) InV = InC->isNullValue() ? FalseVInPred : TrueVInPred; else InV = Builder->CreateSelect(PN->getIncomingValue(i), |