[PATCH] D80400: [DwarfEHPrepare] Don't prune unreachable resumes at optnone

[Nikita Popov via Phabricator via llvm-commits]

nikic created this revision.
nikic added a reviewer: rnk.
Herald added subscribers: llvm-commits, aprantl.
Herald added a project: LLVM.

Disable pruning of unreachable resumes in the DwarfEHPrepare pass at optnone. While I expect the pruning itself to be essentially free, this does require a dominator tree calculation, that is not used for anything else. Saving this DT construction makes for a a 0.4% O0 compile-time improvement <http://llvm-compile-time-tracker.com/compare.php?from=1a15c766f907390f07a98a95e05f749ef42aac09&to=9212ec9fb4c9f36f1d91670c3096f4f6720bbd2f&stat=instructions>.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D80400

Files:
  include/llvm/CodeGen/Passes.h
  lib/CodeGen/DwarfEHPrepare.cpp
  lib/CodeGen/TargetPassConfig.cpp
  test/CodeGen/AArch64/O0-pipeline.ll
  test/CodeGen/X86/O0-pipeline.ll

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