[all-commits] [llvm/llvm-project] 813377: [SCEV] Fully invalidate SCEVUnknown on RAUW

[Nikita Popov via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 8133778d3c8d481891143e21e0c5081a02a9889d
      https://github.com/llvm/llvm-project/commit/8133778d3c8d481891143e21e0c5081a02a9889d
  Author: Nikita Popov <npopov at redhat.com>
  Date:   2022-03-07 (Mon, 07 Mar 2022)

  Changed paths:
    M llvm/lib/Analysis/ScalarEvolution.cpp

  Log Message:
  -----------
  [SCEV] Fully invalidate SCEVUnknown on RAUW

When a SCEVUnknown gets RAUWd, we currently drop it from the folding
set, but don't forget memoized values. I believe we should be
treating RAUW the same way as deletion here and invalidate all
caches and dependent expressions.

I don't have any specific cases where this causes issues right now,
but it does address the FIXME in https://reviews.llvm.org/D119488.

Differential Revision: https://reviews.llvm.org/D120033