[all-commits] [llvm/llvm-project] cd7ea4: [LAA] Drop alias scope metadata that is not valid ...

[Nikita Popov via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: cd7ea4ea657ea41b42fcbd0e6b33faa46608d18e
      https://github.com/llvm/llvm-project/commit/cd7ea4ea657ea41b42fcbd0e6b33faa46608d18e
  Author: Nikita Popov <npopov at redhat.com>
  Date:   2024-01-24 (Wed, 24 Jan 2024)

  Changed paths:
    M llvm/lib/Analysis/LoopAccessAnalysis.cpp
    M llvm/test/Analysis/LoopAccessAnalysis/noalias-scope-decl.ll
    M llvm/test/Transforms/PhaseOrdering/X86/loop-vectorizer-noalias.ll

  Log Message:
  -----------
  [LAA] Drop alias scope metadata that is not valid across iterations (#79161)

LAA currently adds memory locations with their original AATags to AST.
However, scoped alias AATags may be valid only within one loop
iteration, while LAA reasons across iterations.

Fix this by determining which alias scopes are defined inside the loop,
and drop AATags that reference these scopes.

Fixes https://github.com/llvm/llvm-project/issues/79137.