[all-commits] [llvm/llvm-project] c87bd2: [AArch64] Implement .variant_pcs directive

[Cullen Rhodes via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: c87bd2d8eb378d152f2b6bde4cb088ad390a676c
      https://github.com/llvm/llvm-project/commit/c87bd2d8eb378d152f2b6bde4cb088ad390a676c
  Author: Cullen Rhodes <cullen.rhodes at arm.com>
  Date:   2020-10-13 (Tue, 13 Oct 2020)

  Changed paths:
    M llvm/include/llvm/BinaryFormat/ELF.h
    M llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
    M llvm/lib/Target/AArch64/AsmParser/AArch64AsmParser.cpp
    M llvm/lib/Target/AArch64/MCTargetDesc/AArch64ELFStreamer.cpp
    M llvm/lib/Target/AArch64/MCTargetDesc/AArch64TargetStreamer.h
    A llvm/test/CodeGen/AArch64/variant-pcs.ll
    A llvm/test/MC/AArch64/directive-variant_pcs-err.s
    A llvm/test/MC/AArch64/directive-variant_pcs.s

  Log Message:
  -----------
  [AArch64] Implement .variant_pcs directive

A dynamic linker with lazy binding support may need to handle variant
PCS function symbols specially, so an ELF symbol table marking
STO_AARCH64_VARIANT_PCS [1] was added to address this.

Function symbols that follow the vector PCS are marked via the
.variant_pcs assembler directive, which takes a single parameter
specifying the symbol name and sets the STO_AARCH64_VARIANT_PCS st_other
flag in the object file.

[1] https://github.com/ARM-software/abi-aa/blob/master/aaelf64/aaelf64.rst#st-other-values

Reviewed By: sdesmalen

Differential Revision: https://reviews.llvm.org/D89138