[all-commits] [llvm/llvm-project] 2b3725: [BasicAA] Don't track visited blocks for phi-phi a...

[Nikita Popov via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 2b372570ee0be853f61de5feef7fc67b96bf1460
      https://github.com/llvm/llvm-project/commit/2b372570ee0be853f61de5feef7fc67b96bf1460
  Author: Nikita Popov <nikita.ppv at gmail.com>
  Date:   2020-10-22 (Thu, 22 Oct 2020)

  Changed paths:
    M llvm/lib/Analysis/BasicAliasAnalysis.cpp
    M llvm/test/Analysis/BasicAA/phi-aa.ll

  Log Message:
  -----------
  [BasicAA] Don't track visited blocks for phi-phi alias query

We only need the VisitedPhiBBs to disambiguate comparisons of
values from two different loop iterations. If we're comparing
two phis from the same basic block in lock-step, the compared
values will always be on the same iteration.

While this also increases precision, this is mainly intended
to clarify the scope of VisitedPhiBBs.