[all-commits] [llvm/llvm-project] f76544: [LoopUnroll] Clean up exit folding (NFC)

[Nikita Popov via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: f765445a691187c69a8a7c14991acb4589314e93
      https://github.com/llvm/llvm-project/commit/f765445a691187c69a8a7c14991acb4589314e93
  Author: Nikita Popov <nikita.ppv at gmail.com>
  Date:   2021-05-28 (Fri, 28 May 2021)

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

  Log Message:
  -----------
  [LoopUnroll] Clean up exit folding (NFC)

This does some non-functional cleanup of exit folding during
unrolling. The two main changes are:

 * First rewrite latch->header edges, which is unrelated to exit
   folding.
 * Combine folding for latch and non-latch exits. After the
   previous change, the only difference in their logic is that
   for non-latch exits we currently only fold "known non-exit"
   cases, but not "known exit" cases.

I think this helps a lot to clarify this code and prepare it for
future changes.

Differential Revision: https://reviews.llvm.org/D103333