[PATCH] D134600: [RISCV][LLD] Add RISCV zcmt optimise in linker relaxation

[Xinlong Wu via Phabricator via llvm-commits]

VincentWu created this revision.
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This patch implements optimizations for the zcmt extension in lld.

A new `TableJumpSectio` has been added.

Scans each `R_RISCV_CALL/R_RISCV_CALL_PLT` relocType in each section before the linker relaxation, recording the name of the symbol.

In `finalizeContents` the recorded symbol names are sorted in descending order by the number of jumps.

Optimise and insert a new `cm.jt/cm.jalt` during the relax process. in the process, we reused the`R_RISCV_JAL` relocType

co-author: @ScottEgerton


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D134600

Files:
  lld/ELF/Arch/RISCV.cpp
  lld/ELF/Config.h
  lld/ELF/Driver.cpp
  lld/ELF/InputSection.h
  lld/ELF/Options.td
  lld/ELF/SyntheticSections.cpp
  lld/ELF/SyntheticSections.h
  lld/ELF/Target.h
  lld/ELF/Writer.cpp
  lld/test/ELF/riscv-tbljal-call.s
  lld/test/ELF/riscv-tbljal-syms.s

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