diff options
| 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 | 492fd454ca3aa3d45e76c4f42b602e934cf519b1 (patch) | |
| tree | c2405612125a3f8241c34e9d0b52e81d3bf2dcd0 /lib/CodeGen/SelectionDAG/DAGCombiner.cpp | |
| parent | a7f1354eb5289b340220c9138befff89822119b2 (diff) | |
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@104185 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/CodeGen/SelectionDAG/DAGCombiner.cpp')
| -rw-r--r-- | lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index 347024f0ae..0ea46af2ac 100644 --- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/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)) { |