[all-commits] [llvm/llvm-project] 2820a2: Move -fno-semantic-interposition dso_local logic f...

[Fangrui Song via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 2820a2ca3a0e69c3f301845420e0067ffff2251b
      https://github.com/llvm/llvm-project/commit/2820a2ca3a0e69c3f301845420e0067ffff2251b
  Author: Fangrui Song <i at maskray.me>
  Date:   2020-12-29 (Tue, 29 Dec 2020)

  Changed paths:
    M clang/lib/CodeGen/CodeGenModule.cpp
    A clang/test/CodeGen/semantic-interposition-no.c
    M llvm/lib/Target/TargetMachine.cpp
    R llvm/test/CodeGen/X86/semantic-interposition-comdat.ll
    R llvm/test/CodeGen/X86/semantic-interposition-infer-dsolocal.ll

  Log Message:
  -----------
  Move -fno-semantic-interposition dso_local logic from TargetMachine to Clang CodeGenModule

This simplifies TargetMachine::shouldAssumeDSOLocal and and gives frontend the
decision to use dso_local. For LLVM synthesized functions/globals, they may lose
inferred dso_local but such optimizations are probably not very useful.

Note: the hasComdat() condition in canBenefitFromLocalAlias (D77429) may be dead now.
(llvm/CodeGen/X86/semantic-interposition-comdat.ll)
(Investigate whether we need test coverage when Fuchsia C++ ABI is clearer)