[all-commits] [llvm/llvm-project] e976fb: [EarlyCSE] Fix crash with expensive checks after D...

[Krzysztof Parzyszek via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: e976fb1e54f30403ca31764da69cba3769487e6a
      https://github.com/llvm/llvm-project/commit/e976fb1e54f30403ca31764da69cba3769487e6a
  Author: Krzysztof Parzyszek <kparzysz at quicinc.com>
  Date:   2020-09-23 (Wed, 23 Sep 2020)

  Changed paths:
    M llvm/lib/Transforms/Scalar/EarlyCSE.cpp
    A llvm/test/Transforms/EarlyCSE/getmatchingvalue-crash.ll

  Log Message:
  -----------
  [EarlyCSE] Fix crash with expensive checks after D87691

D87691 reordered some checks, which turned out to be unsafe. More
specifically, when examining a store instruction, the check against
getOrCreateResult should be done before attempting to call
isSameMemGeneration. Otherwise a crash in MSSA walker can occur.

This patch restores the order of these calls to what it was originally.