[all-commits] [llvm/llvm-project] 54da54: [SelectionDAG] Avoid one comparison when legalizin...

[Nikita Popov via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 54da543a14da6dd0e594875241494949cb659b08
      https://github.com/llvm/llvm-project/commit/54da543a14da6dd0e594875241494949cb659b08
  Author: Nikita Popov <npopov at redhat.com>
  Date:   2025-06-04 (Wed, 04 Jun 2025)

  Changed paths:
    M llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
    M llvm/test/CodeGen/AArch64/fmaximum-legalization.ll
    M llvm/test/CodeGen/ARM/fp-maximum-legalization.ll
    M llvm/test/CodeGen/NVPTX/bf16-instructions.ll
    M llvm/test/CodeGen/NVPTX/math-intrins.ll
    M llvm/test/CodeGen/PowerPC/fminimum-fmaximum-f128.ll
    M llvm/test/CodeGen/PowerPC/fminimum-fmaximum.ll
    M llvm/test/CodeGen/X86/fminimum-fmaximum-i686.ll
    M llvm/test/CodeGen/X86/fminimum-fmaximum.ll

  Log Message:
  -----------
  [SelectionDAG] Avoid one comparison when legalizing fmaximum (#142732)

When ordering signed zero, only check the sign of one of the values. We
already know at this point that both values must be +/-0.0, so it is
sufficient to check one of them to correctly order them.

For example, for fmaximum, if we know LHS is `+0.0` then we can always
select LHS, value of RHS does not matter. If LHS is `-0.0` we can always
select RHS, value of RHS doesn't matter.



To unsubscribe from these emails, change your notification settings at https://github.com/llvm/llvm-project/settings/notifications