[all-commits] [llvm/llvm-project] 7dcc88: [SCEV] Generalize no-self-wrap check in isLoopInva...

[max-azul via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 7dcc8899174f44b7447bc48a9f2ff27f5458f8b7
      https://github.com/llvm/llvm-project/commit/7dcc8899174f44b7447bc48a9f2ff27f5458f8b7
  Author: Max Kazantsev <mkazantsev at azul.com>
  Date:   2020-11-11 (Wed, 11 Nov 2020)

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

  Log Message:
  -----------
  [SCEV] Generalize no-self-wrap check in isLoopInvariantExitCondDuringFirstIterations

Lift limitation on step being `+/- 1`. In fact, the only thing it is needed for
is proving no-self-wrap. We can instead check this flag directly.

Theoretically it can increase the scope of the transform, but I could not
construct such test easily.

Differential Revision: https://reviews.llvm.org/D91126
Reviewed By: apilipenko