[PATCH] D44608: [x86] put nops into the WriteNop class and customize for Jaguar

[Sanjay Patel via Phabricator via llvm-commits]

spatel updated this revision to Diff 138855.
spatel retitled this revision from "[x86] put nops into the WriteNop class and make latency = 0 for Jaguar" to "[x86] put nops into the WriteNop class and customize for Jaguar".
spatel added a reviewer: andreadb.
spatel added a comment.

Patch updated:

1. Use latency = 1 and specify units for Jaguar. As noted in the comment, this tells the scheduler (and presumably llvm-mca) how to model the resource requirements better even though a nop has no dependencies.
2. Move 'fnop' from the default WriteMicrocoded class to WriteNop. This may not be completely accurate for Jaguar, but it's still closer to the truth (and also for Silvermont based on Agner's tables).


https://reviews.llvm.org/D44608

Files:
  lib/Target/X86/X86InstrFPStack.td
  lib/Target/X86/X86InstrInfo.td
  lib/Target/X86/X86ScheduleBtVer2.td
  test/CodeGen/X86/schedule-x86_64.ll
  test/CodeGen/X86/sse-schedule.ll
  test/CodeGen/X86/x87-schedule.ll

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