[all-commits] [llvm/llvm-project] 6b9882: AArch64: emit `fcmp ord %a, zeroinitializer` as a ...

[Tim Northover via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 6b98824a587ac9e091abf3e180f289647c23a9e9
      https://github.com/llvm/llvm-project/commit/6b98824a587ac9e091abf3e180f289647c23a9e9
  Author: Tim Northover <tnorthover at apple.com>
  Date:   2022-12-07 (Wed, 07 Dec 2022)

  Changed paths:
    M llvm/lib/Target/AArch64/GISel/AArch64PostLegalizerLowering.cpp
    M llvm/test/CodeGen/AArch64/GlobalISel/lower-neon-vector-fcmp.mir
    M llvm/test/CodeGen/AArch64/neon-compare-instructions.ll

  Log Message:
  -----------
  AArch64: emit `fcmp ord %a, zeroinitializer` as a single fcmeq.

Most "ord" checks need two real-world compares to implement, but this is the
canonical form of a "!isnan" check, which is equivalent to comparing the input
for equality against itself.