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| author | Benjamin Kramer <benny.kra@googlemail.com> | 2011-03-11 14:46:49 +0000 |
|---|---|---|
| committer | Benjamin Kramer <benny.kra@googlemail.com> | 2011-03-11 14:46:49 +0000 |
| commit | 391a946fa98296f8f525c060b62f499facaff9d2 (patch) | |
| tree | 4a10409f268b529be3896ecf64e2f7f567fe626a /llvm/lib/Analysis/ValueTracking.cpp | |
| parent | 51897bcd3eead808ec85318b64d42cdda75b9e21 (diff) | |
| download | llvm-391a946fa98296f8f525c060b62f499facaff9d2.zip llvm-391a946fa98296f8f525c060b62f499facaff9d2.tar.gz llvm-391a946fa98296f8f525c060b62f499facaff9d2.tar.bz2 | |
ComputeMaskedBits: sub falls through to add, and sub doesn't have the same overflow semantics as add.
Should fix the selfhost failures that started with r127463.
llvm-svn: 127465
Diffstat (limited to 'llvm/lib/Analysis/ValueTracking.cpp')
| -rw-r--r-- | llvm/lib/Analysis/ValueTracking.cpp | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp index 33fb1e8..6c33d2d 100644 --- a/llvm/lib/Analysis/ValueTracking.cpp +++ b/llvm/lib/Analysis/ValueTracking.cpp @@ -431,7 +431,8 @@ void llvm::ComputeMaskedBits(Value *V, const APInt &Mask, } // Are we still trying to solve for the sign bit? - if (Mask.isNegative() && !KnownZero.isNegative() && !KnownOne.isNegative()){ + if (I->getOpcode() == Instruction::Add && + Mask.isNegative() && !KnownZero.isNegative() && !KnownOne.isNegative()){ OverflowingBinaryOperator *OBO = cast<OverflowingBinaryOperator>(I); if (OBO->hasNoSignedWrap()) { // Adding two positive numbers can't wrap into negative ... |