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| author | Evan Cheng <evan.cheng@apple.com> | 2008-03-10 07:19:13 +0000 |
|---|---|---|
| committer | Evan Cheng <evan.cheng@apple.com> | 2008-03-10 07:19:13 +0000 |
| commit | f79e60649a5edea03bdccf8521d77c15cbb33af4 (patch) | |
| tree | ec61ba44f6cbfaaba814a8a2ab3ab859e8c906ac /lib | |
| parent | 8d88dbcbae38ba4e6d7bd43dd499a13bf091999d (diff) | |
| download | external_llvm-f79e60649a5edea03bdccf8521d77c15cbb33af4.zip external_llvm-f79e60649a5edea03bdccf8521d77c15cbb33af4.tar.gz external_llvm-f79e60649a5edea03bdccf8521d77c15cbb33af4.tar.bz2 | |
Avoid creating BUILD_VECTOR of all zero elements of "non-normalized" type (e.g. v8i16 on x86) after legalizer. Instruction selection does not expect to see them. In all likelihood this can only be an issue in a bugpoint reduced test case.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48136 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib')
| -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 963a1fe..1b00855 100644 --- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -1103,6 +1103,10 @@ SDOperand DAGCombiner::visitSUB(SDNode *N) { // fold (sub x, x) -> 0 if (N0 == N1) + if (ISD::isBuildVectorAllZeros(N0.Val)) + // Zero vectors might be normalized to a particular vector type to ensure + // they are CSE'd. Return it as it is. + return N0; return DAG.getConstant(0, N->getValueType(0)); // fold (sub c1, c2) -> c1-c2 if (N0C && N1C) |