diff options
Diffstat (limited to 'llvm/lib')
| -rw-r--r-- | llvm/lib/Analysis/InstructionSimplify.cpp | 4 | ||||
| -rw-r--r-- | llvm/lib/IR/ConstantFold.cpp | 5 |
2 files changed, 5 insertions, 4 deletions
diff --git a/llvm/lib/Analysis/InstructionSimplify.cpp b/llvm/lib/Analysis/InstructionSimplify.cpp index 1c5a917cbec..408768e8515 100644 --- a/llvm/lib/Analysis/InstructionSimplify.cpp +++ b/llvm/lib/Analysis/InstructionSimplify.cpp @@ -1422,11 +1422,11 @@ static Value *SimplifyAShrInst(Value *Op0, Value *Op1, bool isExact, if (match(Op0, m_AllOnes())) return Op0; - // undef >>a X -> all ones + // undef >>a X -> 0 // undef >>a X -> undef (if it's exact) if (match(Op0, m_Undef())) return isExact ? UndefValue::get(Op0->getType()) - : Constant::getAllOnesValue(Op0->getType()); + : Constant::getNullValue(Op0->getType()); // (X << A) >> A -> X Value *X; diff --git a/llvm/lib/IR/ConstantFold.cpp b/llvm/lib/IR/ConstantFold.cpp index 49ef3024033..a05c594ac8e 100644 --- a/llvm/lib/IR/ConstantFold.cpp +++ b/llvm/lib/IR/ConstantFold.cpp @@ -960,8 +960,9 @@ Constant *llvm::ConstantFoldBinaryInstruction(unsigned Opcode, // X >>a undef -> undef if (isa<UndefValue>(C2)) return C2; - // undef >>a X -> all ones - return Constant::getAllOnesValue(C1->getType()); + // TODO: undef >>a X -> undef if the shift is exact + // undef >>a X -> 0 + return Constant::getNullValue(C1->getType()); case Instruction::Shl: // X << undef -> undef if (isa<UndefValue>(C2)) |
