[all-commits] [llvm/llvm-project] b3722d: [X86] Add a private member function determinePaddi...

[KanRobert via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: b3722dea3bff1e177104180661fc283610c3c22b
      https://github.com/llvm/llvm-project/commit/b3722dea3bff1e177104180661fc283610c3c22b
  Author: Shengchen Kan <shengchen.kan at intel.com>
  Date:   2020-03-05 (Thu, 05 Mar 2020)

  Changed paths:
    M llvm/lib/Target/X86/MCTargetDesc/X86AsmBackend.cpp
    M llvm/lib/Target/X86/MCTargetDesc/X86BaseInfo.h

  Log Message:
  -----------
  [X86] Add a private member function determinePaddingPrefix for X86AsmBackend

Summary: X86 can reduce the bytes of NOP by padding instructions with prefixes to get a better peformance in some cases. So a private member function `determinePaddingPrefix` is added to determine which prefix is the most suitable.

Reviewers: annita.zhang, reames, MaskRay, craig.topper, LuoYuanke, jyknight

Reviewed By: reames

Subscribers: llvm-commits, dexonsmith, hiraditya

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D75357