[all-commits] [llvm/llvm-project] cd8804: [CodeGen][AArch64] Add TargetInstrInfo hook to mod...

[NickGuy-Arm via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: cd880442ae66561e45257f2440321a0a671acae7
      https://github.com/llvm/llvm-project/commit/cd880442ae66561e45257f2440321a0a671acae7
  Author: Nicholas Guy <nicholas.guy at arm.com>
  Date:   2021-02-08 (Mon, 08 Feb 2021)

  Changed paths:
    M llvm/include/llvm/CodeGen/TargetInstrInfo.h
    M llvm/lib/CodeGen/MachineBlockPlacement.cpp
    M llvm/lib/Target/AArch64/AArch64InstrInfo.cpp
    M llvm/lib/Target/AArch64/AArch64InstrInfo.h
    A llvm/test/CodeGen/AArch64/aarch64-tail-dup-size.ll

  Log Message:
  -----------
  [CodeGen][AArch64] Add TargetInstrInfo hook to modify the TailDuplicateSize default threshold

Different targets might handle branch performance differently, so this patch allows for
targets to specify the TailDuplicateSize threshold. Said threshold defines how small a branch
can be and still be duplicated to generate straight-line code instead.
This patch also specifies said override values for the AArch64 subtarget.

Differential Revision: https://reviews.llvm.org/D95631