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| author | Chandler Carruth <chandlerc@gmail.com> | 2015-02-15 07:01:10 +0000 |
|---|---|---|
| committer | Chandler Carruth <chandlerc@gmail.com> | 2015-02-15 07:01:10 +0000 |
| commit | 499d7332c5aafad1f7b20d615e375e332b9b8bfe (patch) | |
| tree | 38e895203c1653da424e225721cbd3a37e530c52 /llvm/lib/CodeGen/SelectionDAG | |
| parent | fe696088398bc934e8b0c661e48d56fec654821b (diff) | |
| download | bcm5719-llvm-499d7332c5aafad1f7b20d615e375e332b9b8bfe.tar.gz bcm5719-llvm-499d7332c5aafad1f7b20d615e375e332b9b8bfe.zip | |
[x86] Fix PR22377, a regression with the new vector shuffle legality
test.
This was just a matter of the DAG combine for vector shuffles being too
aggressive. This is a bit of a grey area, but I think generally if we
can re-use intermediate shuffles, we should. Certainly, given the test
cases I have available, this seems like the right call.
llvm-svn: 229285
Diffstat (limited to 'llvm/lib/CodeGen/SelectionDAG')
| -rw-r--r-- | llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index 747aa43df26..857109119fb 100644 --- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -11770,8 +11770,9 @@ SDValue DAGCombiner::visitVECTOR_SHUFFLE(SDNode *N) { // shuffle(shuffle(A, B, M0), C, M1) -> shuffle(A, C, M2) // shuffle(shuffle(A, B, M0), C, M1) -> shuffle(B, C, M2) // Don't try to fold shuffles with illegal type. - if (N0.getOpcode() == ISD::VECTOR_SHUFFLE && Level < AfterLegalizeDAG && - TLI.isTypeLegal(VT)) { + // Only fold if this shuffle is the only user of the other shuffle. + if (N0.getOpcode() == ISD::VECTOR_SHUFFLE && N->isOnlyUserOf(N0.getNode()) && + Level < AfterLegalizeDAG && TLI.isTypeLegal(VT)) { ShuffleVectorSDNode *OtherSV = cast<ShuffleVectorSDNode>(N0); // The incoming shuffle must be of the same type as the result of the |
