[all-commits] [llvm/llvm-project] 0cb415: [X86][BranchAlign] Suppress branch alignment for {...

[Fangrui Song via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 0cb415c189092e75eaaccabbae41497e446fb3f1
      https://github.com/llvm/llvm-project/commit/0cb415c189092e75eaaccabbae41497e446fb3f1
  Author: Fangrui Song <maskray at google.com>
  Date:   2020-01-18 (Sat, 18 Jan 2020)

  Changed paths:
    M llvm/lib/Target/X86/X86MCInstLower.cpp
    A llvm/test/CodeGen/X86/align-branch-boundary-suppressions-tls.ll

  Log Message:
  -----------
  [X86][BranchAlign] Suppress branch alignment for {,_}__tls_get_addr

The x86-64 General Dynamic TLS code sequence uses prefixes to allow
linker relaxation.  Adding segment override prefix or NOPs can break
linker relaxation (ld -pie/-no-pie).

i386 General Dynamic and x86-64 Local Dynamic do not use prefixes, but
for simplicity, just disable auto padding consistently.

Reviewed By: skan, LuoYuanke

Differential Revision: https://reviews.llvm.org/D72878