diff options
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp | 37 | ||||
| -rw-r--r-- | llvm/test/Transforms/InstCombine/bitcast.ll | 13 |
2 files changed, 8 insertions, 42 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp index 23bf40124b5..4afe1bb243f 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp @@ -1715,40 +1715,6 @@ static Value *optimizeIntegerToVectorInsertions(BitCastInst &CI, 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) { @@ -1920,9 +1886,6 @@ Instruction *InstCombiner::visitBitCast(BitCastInst &CI) { } } - if (Instruction *I = foldBitCastExtElt(CI, *this, DL)) - return I; - if (SrcTy->isPointerTy()) return commonPointerCastTransforms(CI); return commonCastTransforms(CI); diff --git a/llvm/test/Transforms/InstCombine/bitcast.ll b/llvm/test/Transforms/InstCombine/bitcast.ll index 132147f6532..2a8194e5303 100644 --- a/llvm/test/Transforms/InstCombine/bitcast.ll +++ b/llvm/test/Transforms/InstCombine/bitcast.ll @@ -64,7 +64,7 @@ define float @test3(<2 x float> %A, <2 x i64> %B) { ; CHECK-NEXT: ret float %add } -; Both bitcasts are unnecessary; change the extractelement. +; TODO: Both bitcasts are unnecessary; change the extractelement. define float @bitcast_extelt1(<2 x float> %A) { %bc1 = bitcast <2 x float> %A to <2 x i32> @@ -73,11 +73,13 @@ define float @bitcast_extelt1(<2 x float> %A) { ret float %bc2 ; CHECK-LABEL: @bitcast_extelt1( -; CHECK-NEXT: %bc2 = extractelement <2 x float> %A, i32 0 +; CHECK-NEXT: %bc1 = bitcast <2 x float> %A to <2 x i32> +; CHECK-NEXT: %ext = extractelement <2 x i32> %bc1, i32 0 +; CHECK-NEXT: %bc2 = bitcast i32 %ext to float ; CHECK-NEXT: ret float %bc2 } -; Second bitcast can be folded into the first. +; TODO: Second bitcast can be folded into the first. define i64 @bitcast_extelt2(<4 x float> %A) { %bc1 = bitcast <4 x float> %A to <2 x double> @@ -86,8 +88,9 @@ define i64 @bitcast_extelt2(<4 x float> %A) { ret i64 %bc2 ; CHECK-LABEL: @bitcast_extelt2( -; CHECK-NEXT: %bc = bitcast <4 x float> %A to <2 x i64> -; CHECK-NEXT: %bc2 = extractelement <2 x i64> %bc, i32 1 +; CHECK-NEXT: %bc1 = bitcast <4 x float> %A to <2 x double> +; CHECK-NEXT: %ext = extractelement <2 x double> %bc1, i32 1 +; CHECK-NEXT: %bc2 = bitcast double %ext to i64 ; CHECK-NEXT: ret i64 %bc2 } |
