diff options
Diffstat (limited to 'llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp index 3f68d49da68..46d0fcac410 100644 --- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp @@ -1441,6 +1441,11 @@ SDValue SelectionDAG::getVectorShuffle(EVT VT, SDLoc dl, SDValue N1, if (Identity && NElts) return N1; + // Shuffling a constant splat doesn't change the result. + if (N2Undef && N1.getOpcode() == ISD::BUILD_VECTOR) + if (cast<BuildVectorSDNode>(N1)->getConstantSplatValue()) + return N1; + FoldingSetNodeID ID; SDValue Ops[2] = { N1, N2 }; AddNodeIDNode(ID, ISD::VECTOR_SHUFFLE, getVTList(VT), Ops, 2); |
