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| author | Andrea Di Biagio <Andrea_DiBiagio@sn.scee.net> | 2014-01-08 18:33:04 +0000 |
|---|---|---|
| committer | Andrea Di Biagio <Andrea_DiBiagio@sn.scee.net> | 2014-01-08 18:33:04 +0000 |
| commit | 638e97f13512b8424fac28e4ed79964300bcf8b0 (patch) | |
| tree | ee7bee181c2f2fb7357e7ef5cfdd5fd396083abb /lib | |
| parent | 2b5313d26ba58fb70b0333a73693ee453315879c (diff) | |
| download | llvm-638e97f13512b8424fac28e4ed79964300bcf8b0.tar.gz llvm-638e97f13512b8424fac28e4ed79964300bcf8b0.tar.bz2 llvm-638e97f13512b8424fac28e4ed79964300bcf8b0.tar.xz | |
Teach the DAGCombiner how to fold 'vselect' dag nodes according
to the following two rules:
1) fold (vselect (build_vector AllOnes), A, B) -> A
2) fold (vselect (build_vector AllZeros), A, B) -> B
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198777 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index 8f4da5a567..da9559ee87 100644 --- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -4402,6 +4402,13 @@ SDValue DAGCombiner::visitVSELECT(SDNode *N) { return DAG.getNode(ISD::CONCAT_VECTORS, DL, VT, Lo, Hi); } + // Fold (vselect (build_vector all_ones), N1, N2) -> N1 + if (ISD::isBuildVectorAllOnes(N0.getNode())) + return N1; + // Fold (vselect (build_vector all_zeros), N1, N2) -> N2 + if (ISD::isBuildVectorAllZeros(N0.getNode())) + return N2; + return SDValue(); } |