[PATCH] D72463: [Driver][X86] Add -malign-branch* and -malign-branch-within-32B-boundaries

[Fangrui Song via Phabricator via cfe-commits]

MaskRay created this revision.
MaskRay added reviewers: skan, craig.topper, LuoYuanke, annita.zhang, jyknight, reames, chandlerc, tstellar.
Herald added a project: clang.
Herald added a subscriber: cfe-commits.

Based on D72227 <https://reviews.llvm.org/D72227>.

Add -mbranches-within-32B-boundaries to align branches within a 32-Byte
boundary to reduce the potential performance loss of the microcode
update. It is equivalent to the combination of three options:

-malign-branch=fused+jcc+jmp
-malign-branch-boundary=32
-malign-branch-prefix-size=5

Fine-grained -malign-branch* can override individual values.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D72463

Files:
  clang/include/clang/Basic/DiagnosticDriverKinds.td
  clang/include/clang/Driver/Options.td
  clang/lib/Driver/ToolChains/Clang.cpp
  clang/test/Driver/x86-malign-branch.c
  clang/test/Driver/x86-malign-branch.s

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