[PATCH] D78711: AArch64-MachO: use linker-private symbols for jump-tables

[Tim Northover via Phabricator via llvm-commits]

t.p.northover created this revision.
Herald added subscribers: danielkiss, hiraditya, kristof.beyls, mcrosier.
Herald added a project: LLVM.

This kind of kills two birds with one stone:

When they are in `__TEXT,__const` the separate symbols surviving to link stage allow the linker to split and separately dead-code eliminate any orphaned tables (if the functions are not called for example).

When they are at the end of a huge function, we still produce relocations for some reason (could probably be fixed) but MachO only allows 24-bit signed addends so these can be incorrect. Switching to linker-private means the relocations will be against that linker symbol rather than the start of the function and have no addend. Everything will work.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D78711

Files:
  llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
  llvm/lib/Target/AArch64/AArch64MCInstLower.cpp
  llvm/test/CodeGen/AArch64/GlobalISel/arm64e-jump-table-hardening.ll
  llvm/test/CodeGen/AArch64/arm64-jumptable.ll
  llvm/test/CodeGen/AArch64/arm64e-jump-table-hardening.ll
  llvm/test/CodeGen/AArch64/jump-table-32.ll
  llvm/test/CodeGen/AArch64/jump-table.ll

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