[all-commits] [llvm/llvm-project] 6161a8: DAG: Pull fneg out of select feeding fadd into fsub

[Simon Pilgrim via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 6161a8dd5c5a1f190fd964576fb743620e972cc7
      https://github.com/llvm/llvm-project/commit/6161a8dd5c5a1f190fd964576fb743620e972cc7
  Author: Simon Pilgrim <llvm-dev at redking.me.uk>
  Date:   2022-12-19 (Mon, 19 Dec 2022)

  Changed paths:
    M llvm/lib/CodeGen/SelectionDAG/TargetLowering.cpp
    M llvm/test/CodeGen/ARM/fadd-select-fneg-combine.ll

  Log Message:
  -----------
  DAG: Pull fneg out of select feeding fadd into fsub

Enables folding fadd x, (select c, (fneg a), (fneg b))
-> fsub (select a, b), c

Avoids some regressions in a future AMDGPU change.