EVOLUTION-MANAGER

Edit File: primitive_util.h

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==============================================================================*/

// Utilities for dealing with XLA primitive types.

#ifndef TENSORFLOW_COMPILER_XLA_PRIMITIVE_UTIL_H_
#define TENSORFLOW_COMPILER_XLA_PRIMITIVE_UTIL_H_

#include <type_traits>

#include "absl/strings/string_view.h"
#include "tensorflow/compiler/xla/status_macros.h"
#include "tensorflow/compiler/xla/statusor.h"
#include "tensorflow/compiler/xla/types.h"
#include "tensorflow/compiler/xla/xla_data.pb.h"

namespace xla {
namespace primitive_util {

// Returns the count of significand (mantissa) bits for float datatypes.
// For non-float datatypes, results in a LOG(FATAL).
int SignificandWidth(PrimitiveType type);

// The number of exponent bits in a BF16 value.
const int kBFloat16ExponentBits = 8;

// The number of mantissa bits in a BF16 value. There is an implicit leading
// 1, so there is an implicit additional bit of precision.
const int kBFloat16MantissaBits = 7;

// Returns the XLA primitive type (eg, F32) corresponding to the given
// template parameter native type (eg, float).
template <typename NativeT>
PrimitiveType NativeToPrimitiveType() {
  // Make the expression depend on the template parameter NativeT so
  // that this compile-time error only appears if this function is
  // instantiated with some concrete type that is not specialized
  // below.
  static_assert(!std::is_same<NativeT, NativeT>::value,
                "Cannot map native type to primitive type.");
  return PRIMITIVE_TYPE_INVALID;
}

// Declarations of specializations for each native type which correspond to a
// XLA primitive type.  As an optimization, these are declared inline in the
// header.
template <>
inline PrimitiveType NativeToPrimitiveType<bool>() {
  return PRED;
}

// Unsigned integer
template <>
inline PrimitiveType NativeToPrimitiveType<uint8>() {
  return U8;
}

template <>
inline PrimitiveType NativeToPrimitiveType<uint16>() {
  return U16;
}

template <>
inline PrimitiveType NativeToPrimitiveType<uint32>() {
  return U32;
}

template <>
inline PrimitiveType NativeToPrimitiveType<uint64>() {
  return U64;
}

// Signed integer
template <>
inline PrimitiveType NativeToPrimitiveType<int8>() {
  return S8;
}

template <>
inline PrimitiveType NativeToPrimitiveType<int16>() {
  return S16;
}

template <>
inline PrimitiveType NativeToPrimitiveType<int32>() {
  return S32;
}

template <>
inline PrimitiveType NativeToPrimitiveType<int64>() {
  return S64;
}

// Floating point
template <>
inline PrimitiveType NativeToPrimitiveType<float>() {
  return F32;
}

template <>
inline PrimitiveType NativeToPrimitiveType<double>() {
  return F64;
}

template <>
inline PrimitiveType NativeToPrimitiveType<half>() {
  return F16;
}

template <>
inline PrimitiveType NativeToPrimitiveType<bfloat16>() {
  return BF16;
}

// Complex
template <>
inline PrimitiveType NativeToPrimitiveType<complex64>() {
  return C64;
}

template <>
inline PrimitiveType NativeToPrimitiveType<complex128>() {
  return C128;
}

bool IsFloatingPointType(PrimitiveType type);

bool IsComplexType(PrimitiveType type);

bool IsSignedIntegralType(PrimitiveType type);

bool IsUnsignedIntegralType(PrimitiveType type);

bool IsIntegralType(PrimitiveType type);

// Returns true if values of the given primitive type are held in array shapes.
bool IsArrayType(PrimitiveType primitive_type);

// Returns the number of bits in the representation for a given type.
int BitWidth(PrimitiveType type);

PrimitiveType UnsignedIntegralTypeForBitWidth(int64 src_bitwidth);

PrimitiveType SignedIntegralTypeForBitWidth(int64 src_bitwidth);

// Returns the real, imag component type underlying the given complex type.
// LOG(FATAL)'s if complex_type is not complex.
PrimitiveType ComplexComponentType(PrimitiveType complex_type);

// Returns the native type (eg, float) corresponding to the given template
// parameter XLA primitive type (eg, F32).
template <PrimitiveType>
struct PrimitiveTypeToNative;

// Declarations of specializations for each native type which correspond to a
// XLA primitive type.
template <>
struct PrimitiveTypeToNative<PRED> {
  using type = bool;
};

// Unsigned integer
template <>
struct PrimitiveTypeToNative<U8> {
  using type = uint8;
};

template <>
struct PrimitiveTypeToNative<U16> {
  using type = uint16;
};

template <>
struct PrimitiveTypeToNative<U32> {
  using type = uint32;
};

template <>
struct PrimitiveTypeToNative<U64> {
  using type = uint64;
};

// Signed integer
template <>
struct PrimitiveTypeToNative<S8> {
  using type = int8;
};

template <>
struct PrimitiveTypeToNative<S16> {
  using type = int16;
};

template <>
struct PrimitiveTypeToNative<S32> {
  using type = int32;
};

template <>
struct PrimitiveTypeToNative<S64> {
  using type = int64;
};

// Floating point
template <>
struct PrimitiveTypeToNative<F32> {
  using type = float;
};
template <>
struct PrimitiveTypeToNative<F64> {
  using type = double;
};
template <>
struct PrimitiveTypeToNative<F16> {
  using type = half;
};

template <>
struct PrimitiveTypeToNative<BF16> {
  using type = bfloat16;
};

// Complex
template <>
struct PrimitiveTypeToNative<C64> {
  using type = complex64;
};

template <>
struct PrimitiveTypeToNative<C128> {
  using type = complex128;
};

// Returns the lower-case name of the given primitive type.
const string& LowercasePrimitiveTypeName(PrimitiveType s);

// Returns the PrimitiveType matching the given name. The given name is expected
// to be lower-case.
StatusOr<PrimitiveType> StringToPrimitiveType(absl::string_view name);

// Returns true if the given name is a primitive type string (lower-case).
bool IsPrimitiveTypeName(absl::string_view name);

}  // namespace primitive_util
}  // namespace xla

#endif  // TENSORFLOW_COMPILER_XLA_PRIMITIVE_UTIL_H_