[PATCH] D82826: [X86] support .nops directive

[Jian Cai via Phabricator via llvm-commits]

jcai19 updated this revision to Diff 274963.
jcai19 added a comment.

(1) This is a temporary implementation as it breaks the following tests:

  LLVM :: MC/COFF/align-nops.s
  LLVM :: MC/MachO/x86_32-optimal_nop.s
  LLVM :: MC/X86/AlignedBundling/misaligned-bundle-group.s
  LLVM :: MC/X86/AlignedBundling/misaligned-bundle.s
  LLVM :: MC/X86/align-branch-bundle.s
  LLVM :: MC/X86/align-branch-pad-max-prefix.s
  LLVM :: MC/X86/x86_long_nop.s
  LLVM :: MC/X86/x86_nop.s

The breakage was caused by checking X86::Mode32Bit and X86::Mode64Bit in the newly introduced X86AsmBackend::getMaximumNopSize() function. All the above tests would pass if I removed the two checks, but .nops calls would then emit byte-long nop instructions regardless of its second argument.

(2) Will address error messages in the next iteration.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D82826/new/

https://reviews.llvm.org/D82826

Files:
  llvm/include/llvm/MC/MCAsmBackend.h
  llvm/include/llvm/MC/MCFragment.h
  llvm/include/llvm/MC/MCObjectStreamer.h
  llvm/include/llvm/MC/MCStreamer.h
  llvm/lib/MC/MCAssembler.cpp
  llvm/lib/MC/MCFragment.cpp
  llvm/lib/MC/MCObjectStreamer.cpp
  llvm/lib/MC/MCStreamer.cpp
  llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp
  llvm/lib/Target/X86/MCTargetDesc/X86AsmBackend.cpp
  llvm/test/MC/X86/x86-directive-nops-errors.s
  llvm/test/MC/X86/x86-directive-nops.s
  llvm/test/MC/X86/x86_64-directive-nops.s

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