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| author | Bob Wilson <bob.wilson@apple.com> | 2010-05-19 23:42:58 +0000 |
|---|---|---|
| committer | Bob Wilson <bob.wilson@apple.com> | 2010-05-19 23:42:58 +0000 |
| commit | 42603958fb850b95ab987bb547bb7347a0a75e74 (patch) | |
| tree | ad297e7df0acfa8025b5b147dd764313421fb17e /llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp | |
| parent | fa6010b6e4c6f296c5dd99f9933223f16c3c1008 (diff) | |
| download | bcm5719-llvm-42603958fb850b95ab987bb547bb7347a0a75e74.tar.gz bcm5719-llvm-42603958fb850b95ab987bb547bb7347a0a75e74.zip | |
Optimize away insertelement of an undef value. This shows up in
test/Codegen/ARM/reg_sequence.ll but it doesn't affect the generated code
because the coalescer cleans it up. Radar 7998853.
llvm-svn: 104185
Diffstat (limited to 'llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp')
| -rw-r--r-- | llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index 347024f0ae4..0ea46af2acf 100644 --- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -6024,6 +6024,10 @@ SDValue DAGCombiner::visitINSERT_VECTOR_ELT(SDNode *N) { SDValue InVal = N->getOperand(1); SDValue EltNo = N->getOperand(2); + // If the inserted element is an UNDEF, just use the input vector. + if (InVal.getOpcode() == ISD::UNDEF) + return InVec; + // If the invec is a BUILD_VECTOR and if EltNo is a constant, build a new // vector with the inserted element. if (InVec.getOpcode() == ISD::BUILD_VECTOR && isa<ConstantSDNode>(EltNo)) { |
