[PATCH] D76286: [X86][MC] Support enhanced relaxation for branch align

[Kan Shengchen via Phabricator via llvm-commits]

skan added a comment.

Applied D76286 <https://reviews.llvm.org/D76286>,D76475 <https://reviews.llvm.org/D76475> on commit 7b808b105f6aedc4066502b68b71cf205bafa582 <https://reviews.llvm.org/rG7b808b105f6aedc4066502b68b71cf205bafa582>

I collected the memory usage for the prefix padding and NOP padding when building SPEC

With LTO, the prefix padding solution consumes 17% more memory than NOP padding in geomean. The highest outlier is 43%.  Without LTO, the prefix padding solution consumes  5% more memory than NOP padding in geomean. The highest outlier is 28%.

Options for NOP padding: 
-x86-align-branch-boundary=32  -x86-align-branch=fused+jcc+jmp+indirect+call+ret -x86-pad-max-prefix-size=0

Options for prefix padding: 
-x86-align-branch-boundary=32  -x86-align-branch=fused+jcc+jmp+indirect+call+ret -x86-pad-max-prefix-size=5


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D76286/new/

https://reviews.llvm.org/D76286