[all-commits] [llvm/llvm-project] f72fe2: [InstCombine] Preserve FMF in foldLogicOfFCmps.

[Craig Topper via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: f72fe2ef67aac421d77270d0bd9550950a474787
      https://github.com/llvm/llvm-project/commit/f72fe2ef67aac421d77270d0bd9550950a474787
  Author: Craig Topper <craig.topper at sifive.com>
  Date:   2022-03-09 (Wed, 09 Mar 2022)

  Changed paths:
    M llvm/lib/Transforms/InstCombine/InstCombineAndOrXor.cpp
    M llvm/test/Transforms/InstCombine/and-fcmp.ll
    M llvm/test/Transforms/InstCombine/or-fcmp.ll

  Log Message:
  -----------
  [InstCombine] Preserve FMF in foldLogicOfFCmps.

This patch intersects the fast math flags from the two fcmps instead
of dropping them.

I poked at this a bunch with Alive2 for nnan and ninf flags and it seemed
to check out. With the other flags it told me "Couldn't prove the
correctness of the transformation". Not sure if I should just preserve
nnan and ninf?

Reviewed By: spatel, lebedev.ri

Differential Revision: https://reviews.llvm.org/D121243