[all-commits] [llvm/llvm-project] a65497: [LoopUnroll] Don't update DT for changeToUnreachable.

[Florian Hahn via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: a6549718d9ba2fdcd14fb8651aeb5000840fa337
      https://github.com/llvm/llvm-project/commit/a6549718d9ba2fdcd14fb8651aeb5000840fa337
  Author: Florian Hahn <flo at fhahn.com>
  Date:   2023-01-16 (Mon, 16 Jan 2023)

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

  Log Message:
  -----------
  [LoopUnroll] Don't update DT for changeToUnreachable.

There is no need to update the DT here, because there must be a unique
latch. Hence if the latch is not exiting it must directly branch back
to the original loop header and does not dominate any nodes.

Skipping a DT update here simplifies D141487.

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D141810