[PATCH] D113615: [ELF] Make --no-relax disable R_X86_64_{,REX_}GOTPCRELX GOT optimization

[Fangrui Song via Phabricator via llvm-commits]

MaskRay created this revision.
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This brings back the original version of D81359 <https://reviews.llvm.org/D81359>.
I can find several use cases now.

- Unlike GNU ld, LLD's relocation processing is one pass. If we decide to optimize(relax) R_X86_64_{,REX_}GOTPCRELX, we will suppress GOT generation and cannot undo the decision later. Optimizing R_X86_64_REX_GOTPCRELX can usually make it easy to hit `relocation R_X86_64_REX_GOTPCRELX` relocation out of range. Without --no-relax, the user has to recompile with `-Wa,-mrelax-relocations=no`.
- The option would help during my investigationg of the root cause of https://git.kernel.org/linus/09e43968db40c33a73e9ddbfd937f46d5c334924
- There is need for relaxation for AArch64 & RISC-V. Implementing this for x86-64 improves consistency with little target-specific cost (two-line X86_64.cpp change).


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D113615

Files:
  lld/ELF/Arch/X86_64.cpp
  lld/ELF/Config.h
  lld/ELF/Driver.cpp
  lld/ELF/Options.td
  lld/docs/ld.lld.1
  lld/test/ELF/x86-64-gotpc-relax.s

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