[all-commits] [llvm/llvm-project] 19ce5e: RAGreedyStats: Ignore identity COPYs; count COPYs ...

[Matthias Braun via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 19ce5e515fc5059fad8ec9aee1389ac9d109b647
      https://github.com/llvm/llvm-project/commit/19ce5e515fc5059fad8ec9aee1389ac9d109b647
  Author: Matthias Braun <matze at braunis.de>
  Date:   2022-08-17 (Wed, 17 Aug 2022)

  Changed paths:
    M llvm/lib/CodeGen/RegAllocGreedy.cpp
    M llvm/test/CodeGen/AArch64/arm64-spill-remarks.ll
    M llvm/test/CodeGen/X86/statepoint-ra.ll

  Log Message:
  -----------
  RAGreedyStats: Ignore identity COPYs; count COPYs from/to physregs

Improve copy statistics:

- Count copies from or to physical registers: They are used to model function parameters and calling conventions and the register allocator optimizes for them.
- Check physical registers assigned to virtual registers and stop counting "identity" `COPY`s where source and destination is the same physical registers; they will be removed in the `virtregmap` pass anyway.

Differential Revision: https://reviews.llvm.org/D131932