[PATCH] D15857: [InstCombine] Defend against worst-case exponential execution time

[James Molloy via llvm-commits]

jmolloy updated this revision to Diff 44450.
jmolloy added a comment.

Hi Joerg,

Thanks for that bug report. It saved me some embarassment when the asan bot would have picked it up post-commit.

The issue was holding a reference into a DenseMap which can be invalidated during a hashtable resize. This is solved (as in other places in LLVM) by explicitly using a std::map.

James


Repository:
  rL LLVM

http://reviews.llvm.org/D15857

Files:
  include/llvm/Transforms/Utils/Local.h
  lib/CodeGen/CodeGenPrepare.cpp
  lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
  lib/Transforms/Utils/Local.cpp
  test/Transforms/CodeGenPrepare/bitreverse-hang.ll
  test/Transforms/CodeGenPrepare/bitreverse-recognize.ll
  test/Transforms/InstCombine/bitreverse-hang.ll

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