diff options
| -rw-r--r-- | lib/Transforms/Scalar/InstructionCombining.cpp | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp index 3b181c85d2..a1a3333382 100644 --- a/lib/Transforms/Scalar/InstructionCombining.cpp +++ b/lib/Transforms/Scalar/InstructionCombining.cpp @@ -10613,7 +10613,6 @@ static Value *FindScalarElement(Value *V, unsigned EltNo) { } Instruction *InstCombiner::visitExtractElementInst(ExtractElementInst &EI) { - // If vector val is undef, replace extract with scalar undef. if (isa<UndefValue>(EI.getOperand(0))) return ReplaceInstUsesWith(EI, UndefValue::get(EI.getType())); @@ -10623,8 +10622,9 @@ Instruction *InstCombiner::visitExtractElementInst(ExtractElementInst &EI) { return ReplaceInstUsesWith(EI, Constant::getNullValue(EI.getType())); if (ConstantVector *C = dyn_cast<ConstantVector>(EI.getOperand(0))) { - // If vector val is constant with uniform operands, replace EI - // with that operand + // If vector val is constant with all elements the same, replace EI with + // that element. When the elements are not identical, we cannot replace yet + // (we do that below, but only when the index is constant). Constant *op0 = C->getOperand(0); for (unsigned i = 1; i < C->getNumOperands(); ++i) if (C->getOperand(i) != op0) { |