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| author | Sanjay Patel <spatel@rotateright.com> | 2019-11-25 16:07:10 -0500 |
|---|---|---|
| committer | Sanjay Patel <spatel@rotateright.com> | 2019-11-25 16:24:06 -0500 |
| commit | 214683f3b2d6f421c346debf41d545de18cc0caa (patch) | |
| tree | 6ba0786a2486f27fffa50977fb3fc0839dbe13d6 /llvm/lib/CodeGen/SelectionDAG | |
| parent | 3c5142597a451a03db21c2ffe8f6520c7eacce59 (diff) | |
| download | bcm5719-llvm-214683f3b2d6f421c346debf41d545de18cc0caa.tar.gz bcm5719-llvm-214683f3b2d6f421c346debf41d545de18cc0caa.zip | |
[DAGCombiner] avoid crash on out-of-bounds insert index (PR44139)
We already have this simplification at node-creation-time, but
the test from:
https://bugs.llvm.org/show_bug.cgi?id=44139
...shows that we can combine our way to an assert/crash too.
Diffstat (limited to 'llvm/lib/CodeGen/SelectionDAG')
| -rw-r--r-- | llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp index d56e737226e..793352c16d3 100644 --- a/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp @@ -16756,6 +16756,11 @@ SDValue DAGCombiner::visitINSERT_VECTOR_ELT(SDNode *N) { EVT VT = InVec.getValueType(); unsigned NumElts = VT.getVectorNumElements(); + // Insert into out-of-bounds element is undefined. + if (auto *IndexC = dyn_cast<ConstantSDNode>(EltNo)) + if (IndexC->getZExtValue() >= VT.getVectorNumElements()) + return DAG.getUNDEF(VT); + // Remove redundant insertions: // (insert_vector_elt x (extract_vector_elt x idx) idx) -> x if (InVal.getOpcode() == ISD::EXTRACT_VECTOR_ELT && |
