[all-commits] [llvm/llvm-project] 78ba1d: X86: Stop overriding getRegClass

[Matt Arsenault via All-commits]

  Branch: refs/heads/users/arsenm/x86/stop-overriding-getRegClass-2
  Home:   https://github.com/llvm/llvm-project
  Commit: 78ba1dce1a8152119a4290a1ce927b541a3f6b57
      https://github.com/llvm/llvm-project/commit/78ba1dce1a8152119a4290a1ce927b541a3f6b57
  Author: Matt Arsenault <Matthew.Arsenault at amd.com>
  Date:   2026-09-21 (Mon, 21 Sep 2026)

  Changed paths:
    M llvm/include/llvm/CodeGen/TargetInstrInfo.h
    M llvm/lib/Target/X86/X86InstrAMX.td
    M llvm/lib/Target/X86/X86InstrFPStack.td
    M llvm/lib/Target/X86/X86InstrInfo.cpp
    M llvm/lib/Target/X86/X86InstrInfo.h
    M llvm/lib/Target/X86/X86InstrOperands.td
    M llvm/lib/Target/X86/X86InstrPredicates.td
    M llvm/lib/Target/X86/X86InstrSSE.td
    M llvm/lib/Target/X86/X86InstrSystem.td
    M llvm/lib/Target/X86/X86InstrTBM.td
    A llvm/test/MC/X86/apx/no-rex2-reject.s
    A llvm/test/MachineVerifier/X86/apx-norex2-regclass.mir
    A llvm/test/MachineVerifier/X86/lit.local.cfg
    M llvm/utils/TableGen/AsmMatcherEmitter.cpp
    M llvm/utils/TableGen/X86FoldTablesEmitter.cpp
    M llvm/utils/TableGen/X86RecognizableInstr.cpp

  Log Message:
  -----------
  X86: Stop overriding getRegClass

Making TargetInstrInfo::getRegClass virtual was an AMDGPU hack that should not
spread to other backends (X86 overrode it in #70958). The override kept GPR
operands out of the *_NOREX2 subclasses for instructions that cannot encode
r16-r31 with EGPR. Express this constraint with RegClassByHwMode instead, which
allows dropping the virtual.

This also enables the machine verifier to enforce the constraint, which was
previously ignored. Also fixes missing assembler tests enforcing the constraint.
There is custom assembler code for this case which may be deletable after this.

I don't really know about all the X86isms here, AI did most of that.

Co-authored-by: Claude (Opus 4.8) <noreply at anthropic.com>


  Commit: ec4db72cd006671b6328751e28ea7b51efef7490
      https://github.com/llvm/llvm-project/commit/ec4db72cd006671b6328751e28ea7b51efef7490
  Author: Matt Arsenault <Matthew.Arsenault at amd.com>
  Date:   2026-09-21 (Mon, 21 Sep 2026)

  Changed paths:
    M llvm/utils/TableGen/X86FoldTablesEmitter.cpp
    M llvm/utils/TableGen/X86RecognizableInstr.cpp

  Log Message:
  -----------
  Recognize RegClassByHwMode operands in isRegisterOperand


  Commit: 7c115cf8a0d7e718de107389a0b076ead3081006
      https://github.com/llvm/llvm-project/commit/7c115cf8a0d7e718de107389a0b076ead3081006
  Author: Matt Arsenault <Matthew.Arsenault at amd.com>
  Date:   2026-09-21 (Mon, 21 Sep 2026)

  Changed paths:
    M llvm/lib/Target/X86/X86InstrKL.td
    M llvm/lib/Target/X86/X86InstrMMX.td
    M llvm/lib/Target/X86/X86InstrOperands.td
    M llvm/lib/Target/X86/X86InstrSSE.td
    M llvm/test/MC/X86/apx/no-rex2-reject.s
    M llvm/test/MachineVerifier/X86/apx-norex2-regclass.mir
    M llvm/utils/TableGen/X86RecognizableInstr.cpp

  Log Message:
  -----------
  Mark more EGPR incompatible instruction cases


Compare: https://github.com/llvm/llvm-project/compare/1ea7ebb224bb...7c115cf8a0d7

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