[PATCH] D81359: [ELF] Add --[no-]relax for RISC-V

[Fangrui Song via Phabricator via llvm-commits]

MaskRay added a comment.

> In the past we usually never added a code for "sooner or later" when there is a chance that it never be needed. For example, I believe we do not implement all possible relaxations for i386 and nobody seems to care about them. I wouldn't be surprised to see the same situation for RISC-V, though I know almost nothing about it.

In the first revision I added support for x86 as well. It is just a two line change. config->relax it totally justified. (I still don't think it is so useless that we should not implement it. The implementation is trivial.)

> Or may be something else might change, as as far I understand this is only used in linux kernel for RISC-V. It sounds strange to me that this is the only target that needs it (it seems). Why do other targets don't need to stop relaxing? Is it a chance this will be solved differently? I.e. a with a compiler flag may be.

Linker relaxation is more powerful/troublesome on RISC-V: it can rewrite two instructions into one and shrink sections. Many more projects may request --relax or --no-relax if they rely on stable code sequences.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D81359/new/

https://reviews.llvm.org/D81359