[all-commits] [llvm/llvm-project] 6d58f4: [MachineOutliner] NFC: Hide LRU-related stuff behi...

[Jessica Paquette via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 6d58f4ab071eb5c891d662295bcbe240ba507d44
      https://github.com/llvm/llvm-project/commit/6d58f4ab071eb5c891d662295bcbe240ba507d44
  Author: Jessica Paquette <jpaquette at apple.com>
  Date:   2022-02-16 (Wed, 16 Feb 2022)

  Changed paths:
    M llvm/include/llvm/CodeGen/MachineOutliner.h
    M llvm/include/llvm/CodeGen/TargetInstrInfo.h
    M llvm/lib/Target/AArch64/AArch64InstrInfo.cpp
    M llvm/lib/Target/AArch64/AArch64InstrInfo.h
    M llvm/lib/Target/ARM/ARMBaseInstrInfo.cpp
    M llvm/lib/Target/ARM/ARMBaseInstrInfo.h
    M llvm/lib/Target/RISCV/RISCVInstrInfo.cpp
    M llvm/lib/Target/RISCV/RISCVInstrInfo.h
    M llvm/lib/Target/X86/X86InstrInfo.cpp
    M llvm/lib/Target/X86/X86InstrInfo.h

  Log Message:
  -----------
  [MachineOutliner] NFC: Hide LRU-related stuff behind helper functions

It's not particularly user-friendly to have to call `initLRU` everywhere. Also,
it wasn't particularly great that the LRU for registers used in a sequence was
also initialized by `initLRU`.

This patch hides this stuff behind some helper functions:

* `isAvailableAcrossAndOutOfSeq`
* `isAnyUnavailableAcrossOrOutOfSeq`
* `isAvailableInsideSeq`

This allows the user to avoid calling `initLRU` explicitly. Also, it allows
us to separate initializing the used-in-sequence LRU from the main LRU.

Since both ARM and AArch64 check LR liveness in `insertOutlinedCall`, this
refactor requires that we de-const the Candidate there.

Some other quality-of-code improvements:

* LRUs in outliner::Candidate now have more descriptive names
* Use `Register` instead of `unsigned` in some places
* Improve readability in some places by using ranges rather than `std::for_each`

This is a preparatory commit for a larger compile time related change for the
AArch64 outliner.