[all-commits] [llvm/llvm-project] 2d9b6a: [GlobalISel][AArch64] AArch64O0PreLegalizerCombine...

[Tobias Stadler via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 2d9b6a01c7a77ee76a5c279901bca1659a550499
      https://github.com/llvm/llvm-project/commit/2d9b6a01c7a77ee76a5c279901bca1659a550499
  Author: Tobias Stadler <mail at stadler-tobias.de>
  Date:   2024-06-14 (Fri, 14 Jun 2024)

  Changed paths:
    M llvm/include/llvm/CodeGen/GlobalISel/CombinerInfo.h
    M llvm/lib/CodeGen/GlobalISel/Combiner.cpp
    M llvm/lib/Target/AArch64/GISel/AArch64O0PreLegalizerCombiner.cpp
    M llvm/test/CodeGen/AArch64/GlobalISel/localizer-arm64-tti.ll

  Log Message:
  -----------
  [GlobalISel][AArch64] AArch64O0PreLegalizerCombiner: Disable fixed-point iteration (#94291)

This adds an option to CombinerInfo to limit the number of iterations in the
Combiner. This option is then used to disable fixed-point iteration for the
AArch64O0PreLegalizerCombiner. The combines there are simple enough that
code quality impact should be minimal with the current heuristics
(instructions are processed from top to bottom of the basic block,
new/changed instructions are added back to the worklist). Test changes
are due to some instructions not being DCE'd, which has no actual impact
because InstructionSelect performs DCE as well.

AArch64 CTMark O0:
-0.9% geomean compile-time (instruction count)
no change in size..text for any of the benchmarks



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