Use the splat index to generate the desired shuffle. Otherwise we
could only get undefs and the vector shuffle becomes an undef,
generating wrong code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137295 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 217a7bc..ae57328 100644
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -4125,15 +4125,15 @@
int NumElems = SrcVT.getVectorNumElements();
assert(SrcVT.is256BitVector() && "unknown howto handle vector type");
+ assert(SV->isSplat() && "shuffle must be a splat");
- SmallVector<int, 4> Mask;
- for (int i = 0; i < NumElems/2; ++i)
- Mask.push_back(SV->getMaskElt(i));
+ int SplatIdx = SV->getSplatIndex();
+ const int Mask[4] = { SplatIdx, SplatIdx, SplatIdx, SplatIdx };
EVT SVT = EVT::getVectorVT(*DAG.getContext(), SrcVT.getVectorElementType(),
NumElems/2);
SDValue SV1 = DAG.getVectorShuffle(SVT, dl, V1.getOperand(1),
- DAG.getUNDEF(SVT), &Mask[0]);
+ DAG.getUNDEF(SVT), Mask);
SDValue InsV = Insert128BitVector(DAG.getUNDEF(SrcVT), SV1,
DAG.getConstant(0, MVT::i32), DAG, dl);