[all-commits] [llvm/llvm-project] 0ee6ba: [InstCombine] try to forward-propagate some FMF to...

[Sanjay Patel via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 0ee6bad6a6725c2913116a8fa7769b067c219f00
      https://github.com/llvm/llvm-project/commit/0ee6bad6a6725c2913116a8fa7769b067c219f00
  Author: Sanjay Patel <spatel at rotateright.com>
  Date:   2022-12-11 (Sun, 11 Dec 2022)

  Changed paths:
    M llvm/lib/Transforms/InstCombine/InstCombineSelect.cpp
    M llvm/test/Transforms/InstCombine/fabs.ll
    M llvm/test/Transforms/InstCombine/fneg-fabs.ll

  Log Message:
  -----------
  [InstCombine] try to forward-propagate some FMF to select

This is intended to mitigate potential regressions that
would result from restricting this fold for NANs as
discussed in issue #59279.

Ideally, we could do this more generally because we have
known problems seeing/generating FMF on a select, but there
are likely many corner cases that need to verified.

For example, I thought this propagation would be valid
without looking at the condition value and for 'nsz' too,
but according to Alive2, it is not:
https://alive2.llvm.org/ce/z/AnG6As