[all-commits] [llvm/llvm-project] 30001a: [BasicAA] Ignore CanBeFreed in minimal extent reas...

[Nikita Popov via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 30001af84ec5fa0c4f88da1df9c6682bdff44226
      https://github.com/llvm/llvm-project/commit/30001af84ec5fa0c4f88da1df9c6682bdff44226
  Author: Nikita Popov <nikita.ppv at gmail.com>
  Date:   2021-10-04 (Mon, 04 Oct 2021)

  Changed paths:
    M llvm/lib/Analysis/BasicAliasAnalysis.cpp
    M llvm/test/Analysis/BasicAA/dereferenceable.ll

  Log Message:
  -----------
  [BasicAA] Ignore CanBeFreed in minimal extent reasoning

When determining NoAlias based on object size and dereferenceability
information, we can ignore frees for the same reason we can ignore
possible null pointers (if null is not a valid pointer): Actually
accessing the null pointer / freed pointer would be immediate UB,
and AA results are only valid under the assumption of an access.

This addresses a minor regression from D110745.

Differential Revision: https://reviews.llvm.org/D111028