diff options
Diffstat (limited to 'llvm/lib/Analysis/InstructionSimplify.cpp')
| -rw-r--r-- | llvm/lib/Analysis/InstructionSimplify.cpp | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp index 4a80558dd1b..c15f649e9c4 100644 --- a/llvm/lib/Analysis/InstructionSimplify.cpp +++ b/llvm/lib/Analysis/InstructionSimplify.cpp @@ -1162,7 +1162,11 @@ static Value *SimplifyShift(Instruction::BinaryOps Opcode, Value *Op0, return Constant::getNullValue(Op0->getType()); // X shift by 0 -> X - if (match(Op1, m_Zero())) + // Shift-by-sign-extended bool must be shift-by-0 because shift-by-all-ones + // would be poison. + Value *X; + if (match(Op1, m_Zero()) || + (match(Op1, m_SExt(m_Value(X))) && X->getType()->isIntOrIntVectorTy(1))) return Op0; // Fold undefined shifts. |
