[PATCH] D104564: [AArch64][X86] Allow 64-bit label differences lower to IMAGE_REL_*_REL32

[Fangrui Song via Phabricator via llvm-commits]

MaskRay created this revision.
MaskRay added reviewers: mstorsjo, rnk.
Herald added subscribers: wenlei, danielkiss, pengfei, hiraditya, kristof.beyls.
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`IMAGE_REL_ARM64_REL64/IMAGE_REL_AMD64_REL64` do not exist and `.quad a - .` is
currently not representable.

For instrumentation, `.quad a - .` is useful representing a cross-section
reference in a metadata section, to allow ELF medium/large code models. The COFF
limitation makes such generic instrumentations inconvenient. I plan to make a
PGO/coverage metadata section field relative in D104556 <https://reviews.llvm.org/D104556>.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D104564

Files:
  llvm/lib/Target/AArch64/MCTargetDesc/AArch64WinCOFFObjectWriter.cpp
  llvm/lib/Target/X86/MCTargetDesc/X86WinCOFFObjectWriter.cpp
  llvm/test/MC/AArch64/coff-relocations.s
  llvm/test/MC/COFF/cross-section-relative-err.s
  llvm/test/MC/COFF/cross-section-relative.s

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