}
Instruction *InstCombiner::visitExtractElementInst(ExtractElementInst &EI) {
- if (ConstantAggregateZero *C =
- dyn_cast<ConstantAggregateZero>(EI.getOperand(0))) {
- // If packed val is constant 0, replace extract with scalar 0
- const Type *Ty = cast<PackedType>(C->getType())->getElementType();
- return ReplaceInstUsesWith(EI, Constant::getNullValue(Ty));
- }
+ // If packed val is undef, replace extract with scalar undef.
+ if (isa<UndefValue>(EI.getOperand(0)))
+ return ReplaceInstUsesWith(EI, UndefValue::get(EI.getType()));
+
+ // If packed val is constant 0, replace extract with scalar 0.
+ if (isa<ConstantAggregateZero>(EI.getOperand(0)))
+ return ReplaceInstUsesWith(EI, Constant::getNullValue(EI.getType()));
+
if (ConstantPacked *C = dyn_cast<ConstantPacked>(EI.getOperand(0))) {
// If packed val is constant with uniform operands, replace EI
// with that operand