[all-commits] [llvm/llvm-project] 11fcae: [LLVM] Add `__builtin_readsteadycounter` intrinsic...

[Joseph Huber via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 11fcae69dbea4860e20ab799ecca9b0432d7f19d
      https://github.com/llvm/llvm-project/commit/11fcae69dbea4860e20ab799ecca9b0432d7f19d
  Author: Joseph Huber <huberjn at outlook.com>
  Date:   2024-02-13 (Tue, 13 Feb 2024)

  Changed paths:
    M clang/docs/LanguageExtensions.rst
    M clang/docs/ReleaseNotes.rst
    M clang/include/clang/Basic/Builtins.td
    M clang/lib/CodeGen/CGBuiltin.cpp
    M clang/test/CodeGen/builtins.c
    M llvm/include/llvm/CodeGen/ISDOpcodes.h
    M llvm/include/llvm/IR/Intrinsics.td
    M llvm/include/llvm/Support/TargetOpcodes.def
    M llvm/include/llvm/Target/GenericOpcodes.td
    M llvm/include/llvm/Target/GlobalISel/SelectionDAGCompat.td
    M llvm/include/llvm/Target/TargetSelectionDAG.td
    M llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
    M llvm/lib/CodeGen/IntrinsicLowering.cpp
    M llvm/lib/CodeGen/SelectionDAG/LegalizeDAG.cpp
    M llvm/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp
    M llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.h
    M llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
    M llvm/lib/CodeGen/SelectionDAG/SelectionDAGDumper.cpp
    M llvm/lib/CodeGen/TargetLoweringBase.cpp
    M llvm/lib/Target/AMDGPU/AMDGPULegalizerInfo.cpp
    M llvm/lib/Target/AMDGPU/AMDGPURegisterBankInfo.cpp
    M llvm/lib/Target/AMDGPU/SIISelLowering.cpp
    M llvm/lib/Target/AMDGPU/SMInstructions.td
    M llvm/lib/Target/NVPTX/NVPTXISelLowering.cpp
    M llvm/lib/Target/NVPTX/NVPTXInstrInfo.td
    M llvm/lib/Target/NVPTX/NVPTXIntrinsics.td
    M llvm/test/CodeGen/AArch64/GlobalISel/legalizer-info-validation.mir
    A llvm/test/CodeGen/AMDGPU/readsteadycounter.ll
    M llvm/test/CodeGen/NVPTX/intrinsics.ll
    M llvm/test/TableGen/GlobalISelCombinerEmitter/builtins/match-table-replacerreg.td
    M llvm/test/TableGen/GlobalISelCombinerEmitter/match-table-imms.td
    M llvm/test/TableGen/GlobalISelCombinerEmitter/match-table-intrinsics.td
    M llvm/test/TableGen/GlobalISelCombinerEmitter/match-table-patfrag-root.td
    M llvm/test/TableGen/GlobalISelCombinerEmitter/match-table.td
    M llvm/test/TableGen/GlobalISelEmitter.td

  Log Message:
  -----------
  [LLVM] Add `__builtin_readsteadycounter` intrinsic and builtin for realtime clocks (#81331)

Summary:
This patch adds a new intrinsic and builtin function mirroring the
existing `__builtin_readcyclecounter`. The difference is that this
implementation targets a separate counter that some targets have which
returns a fixed frequency clock that can be used to determine elapsed
time, this is different compared to the cycle counter which often has
variable frequency.

This patch only adds support for the NVPTX and AMDGPU targets.

This is done as a new and separate builtin rather than an argument to
`readcyclecounter` to avoid needing to change existing code and to make
the separation more explicit.