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| author | Evan Cheng <evan.cheng@apple.com> | 2009-12-15 00:41:36 +0000 |
|---|---|---|
| committer | Evan Cheng <evan.cheng@apple.com> | 2009-12-15 00:41:36 +0000 |
| commit | ca7c690d3b51f44ccb1ec1bb1c01bd74610b3f8e (patch) | |
| tree | 3dc184fc2633201d68b8c85a470656b183119665 /llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp | |
| parent | d5218331f75a6e3456747ec90e0941612c1a7c4c (diff) | |
| download | bcm5719-llvm-ca7c690d3b51f44ccb1ec1bb1c01bd74610b3f8e.tar.gz bcm5719-llvm-ca7c690d3b51f44ccb1ec1bb1c01bd74610b3f8e.zip | |
Propagate zest through logical shift.
llvm-svn: 91378
Diffstat (limited to 'llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index 027348c0f6d..52b7ed5f158 100644 --- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -3278,6 +3278,16 @@ SDValue DAGCombiner::visitZERO_EXTEND(SDNode *N) { if (SCC.getNode()) return SCC; } + // (zext (shl (zext x), y)) -> (shl (zext x), (zext y)) + if ((N0.getOpcode() == ISD::SHL || N0.getOpcode() == ISD::SRL) && + N0.getOperand(0).getOpcode() == ISD::ZERO_EXTEND && + N0.hasOneUse()) { + DebugLoc dl = N->getDebugLoc(); + return DAG.getNode(N0.getOpcode(), dl, VT, + DAG.getNode(ISD::ZERO_EXTEND, dl, VT, N0.getOperand(0)), + DAG.getNode(ISD::ZERO_EXTEND, dl, VT, N0.getOperand(1))); + } + return SDValue(); } |
