[all-commits] [llvm/llvm-project] 44706b: [InstCombine] Don't add fcmp instructions to stric...

[ostannard via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 44706bd4f0e26f86eda24e4888044897fd4f92a8
      https://github.com/llvm/llvm-project/commit/44706bd4f0e26f86eda24e4888044897fd4f92a8
  Author: ostannard <oliver.stannard at arm.com>
  Date:   2024-02-13 (Tue, 13 Feb 2024)

  Changed paths:
    M llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
    M llvm/test/Transforms/InstCombine/fpclass-check-idioms.ll

  Log Message:
  -----------
  [InstCombine] Don't add fcmp instructions to strictfp functions (#81498)

The strictfp attribute has the requirement that "LLVM will not introduce
any new floating-point instructions that may trap". The llvm.is.fpclass
intrinsic is documented as "The function never raises floating-point
exceptions", and the fcmp instruction may raise one, so we can't
transform the former into the latter in functions with the strictfp
attribute.