AMDGPUTargetParser.h

Go to the documentation of this file.

//===-- AMDGPUTargetParser - Parser for AMDGPU features ---------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file implements a target parser to recognise AMDGPU hardware features.
//
//===----------------------------------------------------------------------===//
 
#ifndef LLVM_TARGETPARSER_AMDGPUTARGETPARSER_H
#define LLVM_TARGETPARSER_AMDGPUTARGETPARSER_H
 
#include "llvm/ADT/Bitset.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/Compiler.h"
#include "llvm/TargetParser/Triple.h"
#include <cstdint>
#include <optional>
#include <string>
#include <utility>
 
namespace llvm {
 
class raw_ostream;
template <typename T> class SmallVectorImpl;
class Triple;
 
namespace AMDGPU {
 
/// GPU kinds supported by the AMDGPU target.
enum GPUKind : uint8_t {
  // Not specified processor.
  GK_NONE = 0,
 
#define GET_R600_GPU_ENUM
#include "llvm/TargetParser/R600TargetParserDef.inc"
 
#define GET_AMDGPU_GPU_ENUM
#include "llvm/TargetParser/AMDGPUTargetParserDef.inc"
};
 
/// One enumerator per frontend-visible feature bit; NUM_FEATURES is the count.
enum AMDGPUFeature : unsigned {
#define GET_AMDGPU_FEATURE_ENUM
#include "llvm/TargetParser/AMDGPUTargetParserDef.inc"
};
 
using AMDGPUFeatureBitset = Bitset<NUM_FEATURES>;
 
/// One enumerator per frontend-visible R600 feature bit; R600_NUM_FEATURES is
/// the count.
enum R600Feature : unsigned {
#define GET_R600_FEATURE_ENUM
#include "llvm/TargetParser/R600TargetParserDef.inc"
};
 
using R600FeatureBitset = Bitset<R600_NUM_FEATURES>;
 
/// Instruction set architecture version.
struct IsaVersion {
  uint8_t Major;
  uint8_t Minor;
  uint8_t Stepping;
 
  bool operator==(const IsaVersion &Other) const {
    return Major == Other.Major && Minor == Other.Minor &&
           Stepping == Other.Stepping;
  }
  bool operator!=(const IsaVersion &Other) const { return !(*this == Other); }
};
 
enum FeatureError : uint32_t {
  NO_ERROR = 0,
  INVALID_FEATURE_COMBINATION,
  UNSUPPORTED_TARGET_FEATURE
};
 
LLVM_ABI StringRef getArchFamilyNameAMDGCN(GPUKind AK);
 
LLVM_ABI Triple::SubArchType getSubArch(GPUKind AK);
 
/// Returns the preferred subarch for a GPU name \p CPU, or NoSubArch if
/// unrecognized.
LLVM_ABI Triple::SubArchType getSubArchFromGPUName(StringRef CPU);
 
LLVM_ABI Triple::SubArchType getMajorSubArch(Triple::SubArchType SubArch);
 
/// Return true if subarch \p A is compatible with subarch \p B, i.e. they are
/// equal or one is the major-family subarch of the other (e.g. AMDGPUSubArch9
/// is compatible with AMDGPUSubArch900). NoSubArch is compatible with anything.
LLVM_ABI bool isSubArchCompatible(const Triple &A, const Triple &B);
LLVM_ABI bool isSubArchCompatible(Triple::SubArchType A, Triple::SubArchType B);
 
/// Return true if the GPU \p AK is usable with the triple subarch \p SubArch.
/// A NoSubArch triple (legacy "amdgcn") accepts any GPU. Otherwise the GPU's
/// subarch must equal \p SubArch, or \p SubArch must be the major-family
/// subarch of the GPU (e.g. the amdgpu9 triple accepts gfx900).
LLVM_ABI bool isCPUValidForSubArch(Triple::SubArchType SubArch, GPUKind AK);
 
/// Convenience overload of isCPUValidForSubArch taking a GPU name \p CPU, which
/// is parsed via parseArchAMDGCN. An unrecognized name is never valid.
LLVM_ABI bool isCPUValidForSubArch(Triple::SubArchType SubArch, StringRef CPU);
 
/// Return true if \p AK is a pseudo target (e.g. "generic"/"generic-hsa"): a
/// recognized AMDGCN GPU that represents no concrete hardware and has no
/// subarch of its own. Such targets are resolved by the backend as a default
/// device but are not valid as an explicit -mcpu.
LLVM_ABI bool isPseudoTarget(GPUKind AK);
 
/// Convenience overload of isPseudoTarget taking a GPU name \p CPU, which is
/// parsed via parseArchAMDGCN.
LLVM_ABI bool isPseudoTarget(StringRef CPU);
 
/// Returns the effective triple appropriate to use when linking \p B into \p A
/// by merging the subarches in case of inexact match.
///
/// In cases where isSubArchCompatible would return / false, returns \p B. This
/// assumes that the non-arch triple components are the same
LLVM_ABI std::string mergeSubArch(const Triple &A, const Triple &B);
 
LLVM_ABI StringRef getArchNameAMDGCN(GPUKind AK);
LLVM_ABI StringRef getArchNameR600(GPUKind AK);
 
/// Returns the canonical GPU name for an AMDGPU subarch, e.g.
/// AMDGPUSubArch1030 -> "gfx1030", AMDGPUSubArch9 -> "gfx9-generic",
/// AMDGPUSubArch6 -> "gfx600". Returns "" for NoSubArch or a non-AMDGPU
/// subarch. The major-only subarches map to their generic/lowest
/// representative, matching the default subtarget for an unspecified -mcpu.
LLVM_ABI StringRef getArchNameFromSubArch(Triple::SubArchType SubArch);
 
/// Returns the triple subarch name for an AMDGPU subarch, e.g.
/// AMDGPUSubArch900 -> "amdgpu9.00". Returns "amdgpu" for NoSubArch.
LLVM_ABI StringRef getSubArchName(Triple::SubArchType SubArch);
LLVM_ABI StringRef getCanonicalArchName(const Triple &T, StringRef Arch);
LLVM_ABI GPUKind parseArchAMDGCN(StringRef CPU);
LLVM_ABI GPUKind parseArchR600(StringRef CPU);
LLVM_ABI GPUKind getGPUKindFromSubArch(Triple::SubArchType SubArch);
 
/// Returns \p AK's feature bitset, or an empty bitset if unknown.
LLVM_ABI const AMDGPUFeatureBitset &getFeatureBitset(GPUKind AK);
 
/// Returns R600 GPU \p AK's feature bitset, or an empty bitset if unknown.
LLVM_ABI const R600FeatureBitset &getFeatureBitsetR600(GPUKind AK);
 
/// Appends the feature name of each bit set in \p Features to \p Names.
LLVM_ABI void getFeatureNames(const AMDGPUFeatureBitset &Features,
                              SmallVectorImpl<StringRef> &Names);
 
/// Append the valid AMDGCN GPU names to \p Values. If \p SubArch is not
/// NoSubArch, only GPUs compatible with that subarch (see isCPUValidForSubArch)
/// are appended.
LLVM_ABI void
fillValidArchListAMDGCN(SmallVectorImpl<StringRef> &Values,
                        Triple::SubArchType SubArch = Triple::NoSubArch);
LLVM_ABI void fillValidArchListR600(SmallVectorImpl<StringRef> &Values);
 
LLVM_ABI IsaVersion getIsaVersion(StringRef GPU);
LLVM_ABI IsaVersion getIsaVersion(Triple::SubArchType SubArch);
 
enum { FIXED_NUM_SGPRS_FOR_INIT_BUG = 96 };
 
LLVM_ABI unsigned getTotalNumSGPRs(GPUKind AK);
LLVM_ABI unsigned getTotalNumSGPRs(Triple::SubArchType SubArch);
 
LLVM_ABI unsigned getAddressableNumSGPRs(GPUKind AK);
LLVM_ABI unsigned getAddressableNumSGPRs(Triple::SubArchType SubArch);
 
LLVM_ABI unsigned getSGPRAllocGranule(GPUKind AK);
LLVM_ABI unsigned getSGPRAllocGranule(Triple::SubArchType SubArch);
 
/// \returns VGPR allocation granularity for \p AK, in registers. \p IsWave32
/// selects the wavefront size, which is a per-kernel mode rather than a
/// property of the GPU. This does not account for dynamic VGPR mode, where the
/// block size chosen by the caller is the granule.
LLVM_ABI unsigned getVGPRAllocGranule(GPUKind AK, bool IsWave32);
LLVM_ABI unsigned getVGPRAllocGranule(Triple::SubArchType SubArch,
                                      bool IsWave32);
 
/// \returns Number of physical VGPRs, i.e. the size of the register file a
/// work-group's waves share. \p IsWave32 selects the wavefront size.
LLVM_ABI unsigned getTotalNumVGPRs(GPUKind AK, bool IsWave32);
LLVM_ABI unsigned getTotalNumVGPRs(Triple::SubArchType SubArch, bool IsWave32);
 
/// \returns Number of VGPRs a single wave can address. On a target with a
/// unified register file this covers the AGPRs as well. This does not account
/// for dynamic VGPR mode, which caps allocation at a fixed number of blocks.
LLVM_ABI unsigned getAddressableNumVGPRs(GPUKind AK, bool IsWave32);
LLVM_ABI unsigned getAddressableNumVGPRs(Triple::SubArchType SubArch,
                                         bool IsWave32);
 
/// \returns Maximum LDS in bytes a single work-group can address. This is a
/// fixed hardware cap and does not depend on how many SIMDs a work-group runs
/// on.
LLVM_ABI unsigned getMaxHWAddressableLocalMemorySize(GPUKind AK);
LLVM_ABI unsigned
getMaxHWAddressableLocalMemorySize(Triple::SubArchType SubArch);
 
/// \returns Number of LDS banks per compute unit.
LLVM_ABI unsigned getLDSBankCount(GPUKind AK);
LLVM_ABI unsigned getLDSBankCount(Triple::SubArchType SubArch);
 
/// \returns Number of SIMDs a work-group's waves run on. All four SIMDs of the
/// functional block in full-SIMD mode, half of them otherwise.
constexpr unsigned getNumWorkGroupSIMDs(bool FullSIMDMode) {
  return FullSIMDMode ? 4 : 2;
}
 
/// \returns Minimum number of waves per execution unit.
constexpr unsigned getMinWavesPerEU() { return 1; }
 
/// \returns Number of bits in the num_records field in a buffer resource,
/// or nullopt if it is not known concretely.
LLVM_ABI std::optional<unsigned> getBufferResourceNumRecordsWidth(GPUKind AK);
LLVM_ABI std::optional<unsigned>
getBufferResourceNumRecordsWidth(Triple::SubArchType SubArch);
 
/// \returns Maximum number of waves per execution unit without any kind of
/// limitation.
LLVM_ABI unsigned getMaxWavesPerEU(GPUKind AK);
LLVM_ABI unsigned getMaxWavesPerEU(Triple::SubArchType SubArch);
 
/// \returns Minimum flat work group size.
constexpr unsigned getMinFlatWorkGroupSize() { return 1; }
 
/// \returns Maximum flat work group size.
constexpr unsigned getMaxFlatWorkGroupSize() {
  // Some subtargets allow encoding 2048, but this isn't tested or supported.
  return 1024;
}
 
/// Fills Features map with default values for given target GPU.
/// \p Features contains overriding target features and this function returns
/// default target features with entries overridden by \p Features.
LLVM_ABI std::pair<FeatureError, StringRef>
fillAMDGPUFeatureMap(StringRef GPU, const Triple &T, StringMap<bool> &Features);
 
enum class TargetIDSetting { Unsupported, Any, Off, On };
 
class LLVM_ABI TargetID {
private:
  GPUKind Arch;
  std::string TargetTripleString;
  TargetIDSetting XnackSetting;
  TargetIDSetting SramEccSetting;
  bool IsAMDHSA;
 
public:
  TargetID(GPUKind Arch, const Triple &TT, TargetIDSetting XnackSetting,
           TargetIDSetting SramEccSetting);
 
  /// Construct a TargetID from a triple \p TT and the processor+features string
  /// e.g. "gfx90a", "gfx90a:xnack+:sramecc-", "".
  TargetID(const Triple &TT, StringRef TargetIDStr);
 
  ~TargetID() = default;
 
  /// \return True if the current xnack setting is not "Unsupported".
  bool isXnackSupported() const {
    return XnackSetting != TargetIDSetting::Unsupported;
  }
 
  /// \returns True if the current xnack setting is "On" or "Any".
  bool isXnackOnOrAny() const {
    return XnackSetting == TargetIDSetting::On ||
           XnackSetting == TargetIDSetting::Any;
  }
 
  /// \returns True if current xnack setting is "On" or "Off",
  /// false otherwise.
  bool isXnackOnOrOff() const {
    return getXnackSetting() == TargetIDSetting::On ||
           getXnackSetting() == TargetIDSetting::Off;
  }
 
  /// \returns The current xnack TargetIDSetting, possible options are
  /// "Unsupported", "Any", "Off", and "On".
  TargetIDSetting getXnackSetting() const { return XnackSetting; }
 
  /// Sets xnack setting to \p NewXnackSetting.
  void setXnackSetting(TargetIDSetting NewXnackSetting) {
    XnackSetting = NewXnackSetting;
  }
 
  /// \return True if the current sramecc setting is not "Unsupported".
  bool isSramEccSupported() const {
    return SramEccSetting != TargetIDSetting::Unsupported;
  }
 
  /// \returns True if the current sramecc setting is "On" or "Any".
  bool isSramEccOnOrAny() const {
    return SramEccSetting == TargetIDSetting::On ||
           SramEccSetting == TargetIDSetting::Any;
  }
 
  /// \returns True if current sramecc setting is "On" or "Off",
  /// false otherwise.
  bool isSramEccOnOrOff() const {
    return getSramEccSetting() == TargetIDSetting::On ||
           getSramEccSetting() == TargetIDSetting::Off;
  }
 
  /// \returns The current sramecc TargetIDSetting, possible options are
  /// "Unsupported", "Any", "Off", and "On".
  TargetIDSetting getSramEccSetting() const { return SramEccSetting; }
 
  /// Sets sramecc setting to \p NewSramEccSetting.
  void setSramEccSetting(TargetIDSetting NewSramEccSetting) {
    SramEccSetting = NewSramEccSetting;
  }
 
  GPUKind getGPUKind() const { return Arch; }
 
  StringRef getTargetTripleString() const { return TargetTripleString; }
 
  /// \returns True if this is an AMDHSA target.
  bool isAMDHSA() const { return IsAMDHSA; }
 
  /// Parse and validate a TargetID for triple \p TT from the processor+features
  /// string \p ProcAndFeatures (e.g. "gfx90a", "gfx90a:xnack+:sramecc-", "").
  /// Returns std::nullopt if the triple is not AMDGCN, the processor is
  /// unrecognized, or a feature modifier is invalid for the processor.
  static std::optional<TargetID> parse(const Triple &TT,
                                       StringRef ProcAndFeatures);
 
  /// Parse and validate a TargetID from a full
  /// "<triple>-<processor>:<features>" directive string.
  static std::optional<TargetID>
  parseTargetIDString(StringRef TargetIDDirective);
 
  /// Construct a TargetID for triple \p TT and processor \p CPU, taking the
  /// xnack/sramecc modes from the subtarget \p FeatureString (a comma-separated
  /// "+xnack,-sramecc" list). Unspecified modes keep the processor's default.
  /// The assembler uses this because it has no target directive to carry the
  /// mode.
  static TargetID createFromSubtargetFeatures(const Triple &TT, StringRef CPU,
                                              StringRef FeatureString);
 
  /// Returns true if \p Other denotes the same target as *this, i.e. the same
  /// processor and xnack/sramecc settings on a compatible triple. This is a
  /// semantic equality that looks through spelling differences.
  bool isEquivalent(const TargetID &Other) const;
 
  /// Returns true if a device image for *this can provide the device code for a
  /// request for \p Other. This is directional and models logical-linking
  /// compatibility.
  bool providesFor(const TargetID &Other) const;
 
  void print(raw_ostream &OS) const;
 
  std::string toString() const;
 
  /// Print the canonical processor name followed by any explicit xnack and
  /// sramecc feature modifiers (e.g. "gfx908:sramecc-:xnack+"), without the
  /// triple prefix.
  void printCanonicalTargetIDString(raw_ostream &OS) const;
 
  /// \returns the canonical processor name followed by any explicit xnack and
  /// sramecc feature modifiers order (e.g.  "gfx908:sramecc-:xnack+"), without
  /// the triple prefix.
  std::string getCanonicalFeatureString() const;
 
  bool operator==(const TargetID &Other) const;
  bool operator!=(const TargetID &Other) const { return !(*this == Other); }
};
 
inline raw_ostream &operator<<(raw_ostream &OS, const TargetID &TargetID) {
  TargetID.print(OS);
  return OS;
}
 
} // namespace AMDGPU
 
} // namespace llvm
 
#endif