diff options
Diffstat (limited to 'lib/CodeGen/SelectionDAG/DAGCombiner.cpp')
-rw-r--r-- | lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index ff5505c977213..6af01423ca106 100644 --- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -16214,23 +16214,29 @@ static SDValue reduceBuildVecToShuffleWithZero(SDNode *BV, SelectionDAG &DAG) { // The build vector contains some number of undef elements and exactly // one other element. That other element must be a zero-extended scalar // extracted from a vector at a constant index to turn this into a shuffle. + // Also, require that the build vector does not implicitly truncate/extend + // its elements. // TODO: This could be enhanced to allow ANY_EXTEND as well as ZERO_EXTEND. + EVT VT = BV->getValueType(0); SDValue Zext = BV->getOperand(ZextElt); if (Zext.getOpcode() != ISD::ZERO_EXTEND || !Zext.hasOneUse() || Zext.getOperand(0).getOpcode() != ISD::EXTRACT_VECTOR_ELT || - !isa<ConstantSDNode>(Zext.getOperand(0).getOperand(1))) + !isa<ConstantSDNode>(Zext.getOperand(0).getOperand(1)) || + Zext.getValueSizeInBits() != VT.getScalarSizeInBits()) return SDValue(); - // The zero-extend must be a multiple of the source size. + // The zero-extend must be a multiple of the source size, and we must be + // building a vector of the same size as the source of the extract element. SDValue Extract = Zext.getOperand(0); unsigned DestSize = Zext.getValueSizeInBits(); unsigned SrcSize = Extract.getValueSizeInBits(); - if (DestSize % SrcSize != 0) + if (DestSize % SrcSize != 0 || + Extract.getOperand(0).getValueSizeInBits() != VT.getSizeInBits()) return SDValue(); // Create a shuffle mask that will combine the extracted element with zeros // and undefs. - int ZextRatio = DestSize / SrcSize; + int ZextRatio = DestSize / SrcSize; int NumMaskElts = NumBVOps * ZextRatio; SmallVector<int, 32> ShufMask(NumMaskElts, -1); for (int i = 0; i != NumMaskElts; ++i) { @@ -16260,7 +16266,7 @@ static SDValue reduceBuildVecToShuffleWithZero(SDNode *BV, SelectionDAG &DAG) { SDValue ZeroVec = DAG.getConstant(0, DL, VecVT); SDValue Shuf = DAG.getVectorShuffle(VecVT, DL, Extract.getOperand(0), ZeroVec, ShufMask); - return DAG.getBitcast(BV->getValueType(0), Shuf); + return DAG.getBitcast(VT, Shuf); } // Check to see if this is a BUILD_VECTOR of a bunch of EXTRACT_VECTOR_ELT |