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| author | Sanjay Patel <spatel@rotateright.com> | 2019-12-02 12:10:05 -0500 |
|---|---|---|
| committer | Sanjay Patel <spatel@rotateright.com> | 2019-12-02 12:17:38 -0500 |
| commit | af4e59949cc4cc895be76a441a2a867189ee0f55 (patch) | |
| tree | 73c01f739c0ec95ca5995e3981fa5c2363d30c1e /llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp | |
| parent | d8d51062256ae59e8c34a94c541119b813b53a79 (diff) | |
| download | bcm5719-llvm-af4e59949cc4cc895be76a441a2a867189ee0f55.tar.gz bcm5719-llvm-af4e59949cc4cc895be76a441a2a867189ee0f55.zip | |
[InstCombine] fix undef propagation for vector urem transform (PR44186)
As described here:
https://bugs.llvm.org/show_bug.cgi?id=44186
The match() code safely allows undef values, but we can't safely
propagate a vector constant that contains an undef to the new
compare instruction.
Diffstat (limited to 'llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp')
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp b/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp index 0b9128a9f5a..f7b39d98d49 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp @@ -1368,8 +1368,10 @@ Instruction *InstCombiner::visitURem(BinaryOperator &I) { } // 1 urem X -> zext(X != 1) - if (match(Op0, m_One())) - return CastInst::CreateZExtOrBitCast(Builder.CreateICmpNE(Op1, Op0), Ty); + if (match(Op0, m_One())) { + Value *Cmp = Builder.CreateICmpNE(Op1, ConstantInt::get(Ty, 1)); + return CastInst::CreateZExtOrBitCast(Cmp, Ty); + } // X urem C -> X < C ? X : X - C, where C >= signbit. if (match(Op1, m_Negative())) { |
