diff options
Diffstat (limited to 'llvm/lib/CodeGen')
| -rw-r--r-- | llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 21 |
1 files changed, 10 insertions, 11 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index 573002a6a4b..ee876b8eb8e 100644 --- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -15114,11 +15114,14 @@ static SDValue simplifyShuffleOperands(ShuffleVectorSDNode *SVN, SDValue N0, static SDValue simplifyShuffleMask(ShuffleVectorSDNode *SVN, SDValue N0, SDValue N1, SelectionDAG &DAG) { - // TODO - handle cases other than BUILD_VECTOR. - auto *BV0 = dyn_cast<BuildVectorSDNode>(N0); - auto *BV1 = dyn_cast<BuildVectorSDNode>(N1); - if (!BV0 && !BV1) - return SDValue(); + auto isUndefElt = [](SDValue V, int Idx) { + // TODO - handle more cases as required. + if (V.getOpcode() == ISD::BUILD_VECTOR) + return V.getOperand(Idx).isUndef(); + if (auto *SVN = dyn_cast<ShuffleVectorSDNode>(V)) + return SVN->getMaskElt(Idx) < 0; + return false; + }; EVT VT = SVN->getValueType(0); unsigned NumElts = VT.getVectorNumElements(); @@ -15127,12 +15130,8 @@ static SDValue simplifyShuffleMask(ShuffleVectorSDNode *SVN, SDValue N0, SmallVector<int, 8> NewMask; for (unsigned i = 0; i != NumElts; ++i) { int Idx = SVN->getMaskElt(i); - if (BV0 && 0 <= Idx && Idx < (int)NumElts && - BV0->getOperand(Idx).isUndef()) { - Changed = true; - Idx = -1; - } else if (BV1 && Idx > (int)NumElts && - BV1->getOperand(Idx - NumElts).isUndef()) { + if ((0 <= Idx && Idx < (int)NumElts && isUndefElt(N0, Idx)) || + ((int)NumElts < Idx && isUndefElt(N1, Idx - NumElts))) { Changed = true; Idx = -1; } |
