[PATCH] D98627: [JumpThreading] Do not use AA after a block has been destroyed. PR43276

[Max Kazantsev via Phabricator via llvm-commits]

mkazantsev created this revision.
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JumpThreading uses Alias Analysis that keeps references to basic blocks in its
internals. At the same time, JumpThreading may delete basic blocks. Under
some circumstances, it may end up querying AA about some blocks that have
been destroyed by this moment. It results in UB.

The proposed solution is to give up using the alias analysis after we've removed
a basic block.


https://reviews.llvm.org/D98627

Files:
  llvm/lib/Transforms/Scalar/JumpThreading.cpp
  llvm/test/Transforms/JumpThreading/pr43276.ll
  llvm/test/Transforms/JumpThreading/thread-loads.ll

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