[all-commits] [llvm/llvm-project] 600624: [LoopVersion] Move an assert [nfc-ish]

[Philip Reames via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 600624a10326ad4be32be409e88b9b8580cef85d
      https://github.com/llvm/llvm-project/commit/600624a10326ad4be32be409e88b9b8580cef85d
  Author: Philip Reames <listmail at philipreames.com>
  Date:   2021-07-06 (Tue, 06 Jul 2021)

  Changed paths:
    M llvm/lib/Transforms/Utils/LoopVersioning.cpp

  Log Message:
  -----------
  [LoopVersion] Move an assert [nfc-ish]


  Commit: 9ffa90d6c27e583bec9656a0aae5062ea5499094
      https://github.com/llvm/llvm-project/commit/9ffa90d6c27e583bec9656a0aae5062ea5499094
  Author: Philip Reames <listmail at philipreames.com>
  Date:   2021-07-06 (Tue, 06 Jul 2021)

  Changed paths:
    M llvm/lib/Transforms/Vectorize/LoopVectorize.cpp

  Log Message:
  -----------
  [LV] Disable epilogue vectorization for non-latch exits

When skimming through old review discussion, I noticed a post commit comment on an earlier patch which had gone unaddressed.  Better late (4 months), than never right?

I'm not aware of an active problem with the combination of non-latch exits and epilogue vectorization, but the interaction was not considered and I'm not modivated to make epilogue vectorization work with early exits. If there were a bug in the interaction, it would be pretty hard to hit right now (as we canonicalize towards bottom tested loops), but an upcoming change to allow multiple exit loops will greatly increase the chance for error.  Thus, let's play it safe for now.


Compare: https://github.com/llvm/llvm-project/compare/74d6ce5d5f16...9ffa90d6c27e