diff options
| -rw-r--r-- | lib/Transforms/InstCombine/InstCombineCasts.cpp | 21 | ||||
| -rw-r--r-- | test/Transforms/InstCombine/bitcast.ll | 8 |
2 files changed, 23 insertions, 6 deletions
diff --git a/lib/Transforms/InstCombine/InstCombineCasts.cpp b/lib/Transforms/InstCombine/InstCombineCasts.cpp index 98fd05a8a3..fbc259b92b 100644 --- a/lib/Transforms/InstCombine/InstCombineCasts.cpp +++ b/lib/Transforms/InstCombine/InstCombineCasts.cpp @@ -1738,11 +1738,22 @@ Instruction *InstCombiner::visitBitCast(BitCastInst &CI) { } if (VectorType *SrcVTy = dyn_cast<VectorType>(SrcTy)) { - if (SrcVTy->getNumElements() == 1 && !DestTy->isVectorTy()) { - Value *Elem = - Builder->CreateExtractElement(Src, - Constant::getNullValue(Type::getInt32Ty(CI.getContext()))); - return CastInst::Create(Instruction::BitCast, Elem, DestTy); + if (SrcVTy->getNumElements() == 1) { + // If our destination is not a vector, then make this a straight + // scalar-scalar cast. + if (!DestTy->isVectorTy()) { + Value *Elem = + Builder->CreateExtractElement(Src, + Constant::getNullValue(Type::getInt32Ty(CI.getContext()))); + return CastInst::Create(Instruction::BitCast, Elem, DestTy); + } + + // Otherwise, see if our source is an insert. If so, then use the scalar + // component directly. + if (InsertElementInst *IEI = + dyn_cast<InsertElementInst>(CI.getOperand(0))) + return CastInst::Create(Instruction::BitCast, IEI->getOperand(1), + DestTy); } } diff --git a/test/Transforms/InstCombine/bitcast.ll b/test/Transforms/InstCombine/bitcast.ll index c980b8926c..1e6113256b 100644 --- a/test/Transforms/InstCombine/bitcast.ll +++ b/test/Transforms/InstCombine/bitcast.ll @@ -137,4 +137,10 @@ define i32 @All111(i32 %in) { ; CHECK: ret i32 0 } - +define <2 x i16> @BitcastInsert(i32 %a) { + %v = insertelement <1 x i32> undef, i32 %a, i32 0 + %r = bitcast <1 x i32> %v to <2 x i16> + ret <2 x i16> %r +; CHECK: @BitcastInsert +; CHECK: bitcast i32 %a to <2 x i16> +} |