//===--- RISCVVIntrinsicUtils.h - RISC-V Vector Intrinsic Utils -*- 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

//

//===----------------------------------------------------------------------===//

#ifndef CLANG_SUPPORT_RISCVVINTRINSICUTILS_H

#define CLANG_SUPPORT_RISCVVINTRINSICUTILS_H

#include "llvm/ADT/ArrayRef.h"

#include "llvm/ADT/BitmaskEnum.h"

#include "llvm/ADT/Optional.h"

#include "llvm/ADT/SmallVector.h"

#include "llvm/ADT/StringRef.h"

#include <cstdint>

#include <string>

#include <vector>

namespace clang {

namespace RISCV {

using VScaleVal = llvm::Optional<unsigned>;

// Modifier for vector type.

enum class VectorTypeModifier : uint8_t {

  NoModifier,

  Widening2XVector,

  Widening4XVector,

  Widening8XVector,

  MaskVector,

  Log2EEW3,

  Log2EEW4,

  Log2EEW5,

  Log2EEW6,

  FixedSEW8,

  FixedSEW16,

  FixedSEW32,

  FixedSEW64,

  LFixedLog2LMULN3,

  LFixedLog2LMULN2,

  LFixedLog2LMULN1,

  LFixedLog2LMUL0,

  LFixedLog2LMUL1,

  LFixedLog2LMUL2,

  LFixedLog2LMUL3,

  SFixedLog2LMULN3,

  SFixedLog2LMULN2,

  SFixedLog2LMULN1,

  SFixedLog2LMUL0,

  SFixedLog2LMUL1,

  SFixedLog2LMUL2,

  SFixedLog2LMUL3,

};

// Similar to basic type but used to describe what's kind of type related to

// basic vector type, used to compute type info of arguments.

enum class BaseTypeModifier : uint8_t {

  Invalid,

  Scalar,

  Vector,

  Void,

  SizeT,

  Ptrdiff,

  UnsignedLong,

  SignedLong,

};

// Modifier for type, used for both scalar and vector types.

enum class TypeModifier : uint8_t {

  NoModifier = 0,

  Pointer = 1 << 0,

  Const = 1 << 1,

  Immediate = 1 << 2,

  UnsignedInteger = 1 << 3,

  SignedInteger = 1 << 4,

  Float = 1 << 5,

  // LMUL1 should be kind of VectorTypeModifier, but that might come with

  // Widening2XVector for widening reduction.

  // However that might require VectorTypeModifier become bitmask rather than

  // simple enum, so we decide keek LMUL1 in TypeModifier for code size

  // optimization of clang binary size.

  LMUL1 = 1 << 6,

  MaxOffset = 6,

  LLVM_MARK_AS_BITMASK_ENUM(LMUL1),

};

// PrototypeDescriptor is used to compute type info of arguments or return

// value.

struct PrototypeDescriptor {

  constexpr PrototypeDescriptor() = default;

  constexpr PrototypeDescriptor(

      BaseTypeModifier PT,

      VectorTypeModifier VTM = VectorTypeModifier::NoModifier,

      TypeModifier TM = TypeModifier::NoModifier)

      : PT(static_cast<uint8_t>(PT)), VTM(static_cast<uint8_t>(VTM)),

        TM(static_cast<uint8_t>(TM)) {}

  constexpr PrototypeDescriptor(uint8_t PT, uint8_t VTM, uint8_t TM)

      : PT(PT), VTM(VTM), TM(TM) {}

  uint8_t PT = static_cast<uint8_t>(BaseTypeModifier::Invalid);

  uint8_t VTM = static_cast<uint8_t>(VectorTypeModifier::NoModifier);

  uint8_t TM = static_cast<uint8_t>(TypeModifier::NoModifier);

  bool operator!=(const PrototypeDescriptor &PD) const {

    return PD.PT != PT || PD.VTM != VTM || PD.TM != TM;

  }

  bool operator>(const PrototypeDescriptor &PD) const {

    return !(PD.PT <= PT && PD.VTM <= VTM && PD.TM <= TM);

  }

  static const PrototypeDescriptor Mask;

  static const PrototypeDescriptor Vector;

  static const PrototypeDescriptor VL;

  static llvm::Optional<PrototypeDescriptor>

  parsePrototypeDescriptor(llvm::StringRef PrototypeStr);

};

llvm::SmallVector<PrototypeDescriptor>

parsePrototypes(llvm::StringRef Prototypes);

// Basic type of vector type.

enum class BasicType : uint8_t {

  Unknown = 0,

  Int8 = 1 << 0,

  Int16 = 1 << 1,

  Int32 = 1 << 2,

  Int64 = 1 << 3,

  Float16 = 1 << 4,

  Float32 = 1 << 5,

  Float64 = 1 << 6,

  MaxOffset = 6,

  LLVM_MARK_AS_BITMASK_ENUM(Float64),

};

// Type of vector type.

enum ScalarTypeKind : uint8_t {

  Void,

  Size_t,

  Ptrdiff_t,

  UnsignedLong,

  SignedLong,

  Boolean,

  SignedInteger,

  UnsignedInteger,

  Float,

  Invalid,

};

// Exponential LMUL

struct LMULType {

  int Log2LMUL;

  LMULType(int Log2LMUL);

  // Return the C/C++ string representation of LMUL

  std::string str() const;

  llvm::Optional<unsigned> getScale(unsigned ElementBitwidth) const;

  void MulLog2LMUL(int Log2LMUL);

};

class RVVType;

using RVVTypePtr = RVVType *;

using RVVTypes = std::vector<RVVTypePtr>;

// This class is compact representation of a valid and invalid RVVType.

class RVVType {

  BasicType BT;

  ScalarTypeKind ScalarType = Invalid;

  LMULType LMUL;

  bool IsPointer = false;

  // IsConstant indices are "int", but have the constant expression.

  bool IsImmediate = false;

  // Const qualifier for pointer to const object or object of const type.

  bool IsConstant = false;

  unsigned ElementBitwidth = 0;

  VScaleVal Scale = 0;

  bool Valid;

  std::string BuiltinStr;

  std::string ClangBuiltinStr;

  std::string Str;

  std::string ShortStr;

  enum class FixedLMULType { LargerThan, SmallerThan };

public:

  RVVType() : BT(BasicType::Unknown), LMUL(0), Valid(false) {}

  RVVType(BasicType BT, int Log2LMUL, const PrototypeDescriptor &Profile);

  // Return the string representation of a type, which is an encoded string for

  // passing to the BUILTIN() macro in Builtins.def.

  const std::string &getBuiltinStr() const { return BuiltinStr; }

  // Return the clang builtin type for RVV vector type which are used in the

  // riscv_vector.h header file.

  const std::string &getClangBuiltinStr() const { return ClangBuiltinStr; }

  // Return the C/C++ string representation of a type for use in the

  // riscv_vector.h header file.

  const std::string &getTypeStr() const { return Str; }

  // Return the short name of a type for C/C++ name suffix.

  const std::string &getShortStr() {

    // Not all types are used in short name, so compute the short name by

    // demanded.

    if (ShortStr.empty())

      initShortStr();

    return ShortStr;

  }

  bool isValid() const { return Valid; }

  bool isScalar() const { return Scale.hasValue() && Scale.getValue() == 0; }

  bool isVector() const { return Scale.hasValue() && Scale.getValue() != 0; }

  bool isVector(unsigned Width) const {

    return isVector() && ElementBitwidth == Width;

  }

  bool isFloat() const { return ScalarType == ScalarTypeKind::Float; }

  bool isSignedInteger() const {

    return ScalarType == ScalarTypeKind::SignedInteger;

  }

  bool isFloatVector(unsigned Width) const {

    return isVector() && isFloat() && ElementBitwidth == Width;

  }

  bool isFloat(unsigned Width) const {

    return isFloat() && ElementBitwidth == Width;

  }

private:

  // Verify RVV vector type and set Valid.

  bool verifyType() const;

  // Creates a type based on basic types of TypeRange

  void applyBasicType();

  // Applies a prototype modifier to the current type. The result maybe an

  // invalid type.

  void applyModifier(const PrototypeDescriptor &prototype);

  void applyLog2EEW(unsigned Log2EEW);

  void applyFixedSEW(unsigned NewSEW);

  void applyFixedLog2LMUL(int Log2LMUL, enum FixedLMULType Type);

  // Compute and record a string for legal type.

  void initBuiltinStr();

  // Compute and record a builtin RVV vector type string.

  void initClangBuiltinStr();

  // Compute and record a type string for used in the header.

  void initTypeStr();

  // Compute and record a short name of a type for C/C++ name suffix.

  void initShortStr();

public:

  /// Compute output and input types by applying different config (basic type

  /// and LMUL with type transformers). It also record result of type in legal

  /// or illegal set to avoid compute the same config again. The result maybe

  /// have illegal RVVType.

  static llvm::Optional<RVVTypes>

  computeTypes(BasicType BT, int Log2LMUL, unsigned NF,

               llvm::ArrayRef<PrototypeDescriptor> PrototypeSeq);

  static llvm::Optional<RVVTypePtr> computeType(BasicType BT, int Log2LMUL,

                                                PrototypeDescriptor Proto);

};

using RISCVPredefinedMacroT = uint8_t;

enum RISCVPredefinedMacro : RISCVPredefinedMacroT {

  Basic = 0,

  V = 1 << 1,

  Zvfh = 1 << 2,

  RV64 = 1 << 3,

  VectorMaxELen64 = 1 << 4,

  VectorMaxELenFp32 = 1 << 5,

  VectorMaxELenFp64 = 1 << 6,

};

enum PolicyScheme : uint8_t {

  SchemeNone,

  HasPassthruOperand,

  HasPolicyOperand,

};

// TODO refactor RVVIntrinsic class design after support all intrinsic

// combination. This represents an instantiation of an intrinsic with a

// particular type and prototype

class RVVIntrinsic {

private:

  std::string BuiltinName; // Builtin name

  std::string Name;        // C intrinsic name.

  std::string MangledName;

  std::string IRName;

  bool IsMasked;

  bool HasVL;

  PolicyScheme Scheme;

  bool HasUnMaskedOverloaded;

  bool HasBuiltinAlias;

  std::string ManualCodegen;

  RVVTypePtr OutputType; // Builtin output type

  RVVTypes InputTypes;   // Builtin input types

  // The types we use to obtain the specific LLVM intrinsic. They are index of

  // InputTypes. -1 means the return type.

  std::vector<int64_t> IntrinsicTypes;

  RISCVPredefinedMacroT RISCVPredefinedMacros = 0;

  unsigned NF = 1;

public:

  RVVIntrinsic(llvm::StringRef Name, llvm::StringRef Suffix, llvm::StringRef MangledName,

               llvm::StringRef MangledSuffix, llvm::StringRef IRName, bool IsMasked,

               bool HasMaskedOffOperand, bool HasVL, PolicyScheme Scheme,

               bool HasUnMaskedOverloaded, bool HasBuiltinAlias,

               llvm::StringRef ManualCodegen, const RVVTypes &Types,

               const std::vector<int64_t> &IntrinsicTypes,

               const std::vector<llvm::StringRef> &RequiredFeatures, unsigned NF);

  ~RVVIntrinsic() = default;

  RVVTypePtr getOutputType() const { return OutputType; }

  const RVVTypes &getInputTypes() const { return InputTypes; }

  llvm::StringRef getBuiltinName() const { return BuiltinName; }

  llvm::StringRef getName() const { return Name; }

  llvm::StringRef getMangledName() const { return MangledName; }

  bool hasVL() const { return HasVL; }

  bool hasPolicy() const { return Scheme != SchemeNone; }

  bool hasPassthruOperand() const { return Scheme == HasPassthruOperand; }

  bool hasPolicyOperand() const { return Scheme == HasPolicyOperand; }

  bool hasUnMaskedOverloaded() const { return HasUnMaskedOverloaded; }

  bool hasBuiltinAlias() const { return HasBuiltinAlias; }

  bool hasManualCodegen() const { return !ManualCodegen.empty(); }

  bool isMasked() const { return IsMasked; }

  llvm::StringRef getIRName() const { return IRName; }

  llvm::StringRef getManualCodegen() const { return ManualCodegen; }

  PolicyScheme getPolicyScheme() const { return Scheme; }

  RISCVPredefinedMacroT getRISCVPredefinedMacros() const {

    return RISCVPredefinedMacros;

  }

  unsigned getNF() const { return NF; }

  const std::vector<int64_t> &getIntrinsicTypes() const {

    return IntrinsicTypes;

  }

  // Return the type string for a BUILTIN() macro in Builtins.def.

  std::string getBuiltinTypeStr() const;

  static std::string getSuffixStr(

      BasicType Type, int Log2LMUL,

      const llvm::SmallVector<PrototypeDescriptor> &PrototypeDescriptors);

};

} // end namespace RISCV

} // end namespace clang

#endif // CLANG_SUPPORT_RISCVVINTRINSICUTILS_H