diff options
| author | Hao Liu <Hao.Liu@arm.com> | 2013-05-13 02:07:05 +0000 |
|---|---|---|
| committer | Hao Liu <Hao.Liu@arm.com> | 2013-05-13 02:07:05 +0000 |
| commit | 3778c04b2e3bc879cb7f175ba4d42f23fb9cef76 (patch) | |
| tree | d362021d1e3028b1154e3b8473dd3eecaba168e8 /lib/CodeGen | |
| parent | 4a971705bc6030dc2e4338b3cd5cffa2e0f88b7b (diff) | |
Fix PR15950 A bug in DAG Combiner about undef mask
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181682 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/CodeGen')
| -rw-r--r-- | lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 35 |
1 files changed, 25 insertions, 10 deletions
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index c54dffbb13..076684993a 100644 --- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -9254,19 +9254,34 @@ static SDValue partitionShuffleOfConcats(SDNode *N, SelectionDAG &DAG) { for (unsigned I = 0; I != NumConcats; ++I) { // Make sure we're dealing with a copy. unsigned Begin = I * NumElemsPerConcat; - if (SVN->getMaskElt(Begin) % NumElemsPerConcat != 0) - return SDValue(); + bool AllUndef = true, NoUndef = true; + for (unsigned J = Begin; J != Begin + NumElemsPerConcat; ++J) { + if (SVN->getMaskElt(J) >= 0) + AllUndef = false; + else + NoUndef = false; + } - for (unsigned J = 1; J != NumElemsPerConcat; ++J) { - if (SVN->getMaskElt(Begin + J - 1) + 1 != SVN->getMaskElt(Begin + J)) + if (NoUndef) { + unsigned Begin = I * NumElemsPerConcat; + if (SVN->getMaskElt(Begin) % NumElemsPerConcat != 0) return SDValue(); - } - unsigned FirstElt = SVN->getMaskElt(Begin) / NumElemsPerConcat; - if (FirstElt < N0.getNumOperands()) - Ops.push_back(N0.getOperand(FirstElt)); - else - Ops.push_back(N1.getOperand(FirstElt - N0.getNumOperands())); + for (unsigned J = 1; J != NumElemsPerConcat; ++J) + if (SVN->getMaskElt(Begin + J - 1) + 1 != SVN->getMaskElt(Begin + J)) + return SDValue(); + + unsigned FirstElt = SVN->getMaskElt(Begin) / NumElemsPerConcat; + if (FirstElt < N0.getNumOperands()) + Ops.push_back(N0.getOperand(FirstElt)); + else + Ops.push_back(N1.getOperand(FirstElt - N0.getNumOperands())); + + } else if (AllUndef) { + Ops.push_back(DAG.getUNDEF(N0.getOperand(0).getValueType())); + } else { // Mixed with general masks and undefs, can't do optimization. + return SDValue(); + } } return DAG.getNode(ISD::CONCAT_VECTORS, N->getDebugLoc(), VT, Ops.data(), |