[all-commits] [llvm/llvm-project] 0d9107: [ValueTracking] Don't require strictly positive fo...

[Nikita Popov via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 0d91075f772d3f0e2cf6449b534a726d4d944c62
      https://github.com/llvm/llvm-project/commit/0d91075f772d3f0e2cf6449b534a726d4d944c62
  Author: Nikita Popov <nikita.ppv at gmail.com>
  Date:   2021-04-14 (Wed, 14 Apr 2021)

  Changed paths:
    M llvm/lib/Analysis/ValueTracking.cpp
    M llvm/test/Analysis/ValueTracking/monotonic-phi.ll

  Log Message:
  -----------
  [ValueTracking] Don't require strictly positive for mul nsw recurrence

Just like in the mul nuw case, it's sufficient that the step is
non-zero. If the step is negative, then the values will jump
between positive and negative, "crossing" zero, but the value of
the recurrence is never actually zero.