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| author | Matt Arsenault <Matthew.Arsenault@amd.com> | 2017-03-21 16:20:16 +0000 |
|---|---|---|
| committer | Matt Arsenault <Matthew.Arsenault@amd.com> | 2017-03-21 16:20:16 +0000 |
| commit | dce313c3cf3948b057428ee97145d7641951afbb (patch) | |
| tree | 6dda11bdbbe0762e45a2ebefd84826c323644c80 /llvm/lib/CodeGen | |
| parent | 3bf24449b074f11f17935af7b928d4eea852f1ef (diff) | |
| download | bcm5719-llvm-dce313c3cf3948b057428ee97145d7641951afbb.tar.gz bcm5719-llvm-dce313c3cf3948b057428ee97145d7641951afbb.zip | |
DAG: Fold bitcast/extract_vector_elt of undef to undef
Fixes not eliminating store when intrinsic is lowered to undef.
llvm-svn: 298385
Diffstat (limited to 'llvm/lib/CodeGen')
| -rw-r--r-- | llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index 40ce46a0d79..bc051f07bb2 100644 --- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -8320,6 +8320,9 @@ SDValue DAGCombiner::visitBITCAST(SDNode *N) { SDValue N0 = N->getOperand(0); EVT VT = N->getValueType(0); + if (N0.isUndef()) + return DAG.getUNDEF(VT); + // If the input is a BUILD_VECTOR with all constant elements, fold this now. // Only do this before legalize, since afterward the target may be depending // on the bitconvert. @@ -13189,6 +13192,9 @@ SDValue DAGCombiner::visitEXTRACT_VECTOR_ELT(SDNode *N) { EVT VT = InVec.getValueType(); EVT NVT = N->getValueType(0); + if (InVec.isUndef()) + return DAG.getUNDEF(NVT); + if (InVec.getOpcode() == ISD::SCALAR_TO_VECTOR) { // Check if the result type doesn't match the inserted element type. A // SCALAR_TO_VECTOR may truncate the inserted element and the |
