return Result;
}
-/// Given a bitcasted vector fed into an extract element instruction and then
-/// bitcasted again, eliminate at least one bitcast by changing the vector type
-/// of the extractelement instruction.
-/// Example:
-/// bitcast (extractelement (bitcast <2 x float> %X to <2 x i32>), 1) to float
-/// --->
-/// extractelement <2 x float> %X, i32 1
-static Instruction *foldBitCastExtElt(BitCastInst &BitCast, InstCombiner &IC,
- const DataLayout &DL) {
- // TODO: Create and use a pattern matcher for ExtractElementInst.
- auto *ExtElt = dyn_cast<ExtractElementInst>(BitCast.getOperand(0));
- if (!ExtElt || !ExtElt->hasOneUse())
- return nullptr;
-
- Value *InnerBitCast = nullptr;
- if (!match(ExtElt->getOperand(0), m_BitCast(m_Value(InnerBitCast))))
- return nullptr;
-
- VectorType *VecType = cast<VectorType>(InnerBitCast->getType());
- Type *DestType = BitCast.getType();
-
- // If the element type of the vector doesn't match the result type,
- // bitcast it to a vector type that we can extract from.
- if (VecType->getElementType() != DestType) {
- unsigned VecWidth = VecType->getPrimitiveSizeInBits();
- unsigned DestWidth = DestType->getPrimitiveSizeInBits();
- unsigned NumElts = VecWidth / DestWidth;
- VecType = VectorType::get(DestType, NumElts);
- InnerBitCast = IC.Builder->CreateBitCast(InnerBitCast, VecType, "bc");
- }
-
- return ExtractElementInst::Create(InnerBitCast, ExtElt->getOperand(1));
-}
-
static Instruction *foldVecTruncToExtElt(Value *VecInput, Type *DestTy,
unsigned ShiftAmt, InstCombiner &IC,
const DataLayout &DL) {
}
}
- if (Instruction *I = foldBitCastExtElt(CI, *this, DL))
- return I;
-
if (SrcTy->isPointerTy())
return commonPointerCastTransforms(CI);
return commonCastTransforms(CI);