[all-commits] [llvm/llvm-project] cfd911: [X86] Skip unused VRegs traverse (#78229)

[Evgenii Kudriashov via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: cfd91199caed12b3f40ab35cf7f6c7fbce38d776
      https://github.com/llvm/llvm-project/commit/cfd91199caed12b3f40ab35cf7f6c7fbce38d776
  Author: Evgenii Kudriashov <evgenii.kudriashov at intel.com>
  Date:   2024-01-26 (Fri, 26 Jan 2024)

  Changed paths:
    M llvm/lib/Target/X86/X86DomainReassignment.cpp
    M llvm/lib/Target/X86/X86FastPreTileConfig.cpp
    M llvm/test/CodeGen/X86/AMX/amx-fastpreconfig.mir
    M llvm/test/CodeGen/X86/domain-reassignment.mir

  Log Message:
  -----------
  [X86] Skip unused VRegs traverse (#78229)

Almost all loops with getNumVirtRegs skip unused registers by means
of reg_nodbg_empty or empty live interval. Except for these two cases
that are revealed by GlobalISel since it can skip RegClass assignment
for unused registers.

Closes #64452, closes #71926