TypeTraits.hpp

// Copyright (c) 2017 Graphcore Ltd. All rights reserved.
 
#ifndef poplar_TypeTraits_hpp
#define poplar_TypeTraits_hpp
 
#include <cstdint>
#include <type_traits>
#include <vector>
 
namespace poplar {
 
// A half type internal to Poplar.
class IeeeHalf;
 
// A quarter type internal to Poplar.
class Quarter;
 
struct TypeTraits {
 
  std::size_t size;
  std::size_t align;
  bool isIntegral;
  bool isFloat;
  bool isSigned;
 
  template <typename T> static TypeTraits make();
 
  template <typename T> static constexpr bool isSimpleType();
 
  template <typename T> static constexpr bool requiresMetadata();
 
  bool isSimpleType() const { return isIntegral || isFloat; }
};
 
template <typename T> TypeTraits TypeTraits::make() {
  TypeTraits t;
  t.size = sizeof(T);
  t.align = std::alignment_of<T>::value;
  t.isIntegral = std::is_integral<T>::value;
  t.isFloat = std::is_floating_point<T>::value;
  t.isSigned = std::is_signed<T>::value;
  return t;
}
 
template <> inline TypeTraits TypeTraits::make<IeeeHalf>() {
  TypeTraits t;
  t.size = sizeof(uint16_t);
  t.align = std::alignment_of<uint16_t>::value;
  t.isIntegral = false;
  t.isFloat = true;
  t.isSigned = true;
  return t;
}
 
template <> inline TypeTraits TypeTraits::make<Quarter>() {
  TypeTraits t;
  t.size = sizeof(uint8_t);
  t.align = std::alignment_of<uint8_t>::value;
  t.isIntegral = false;
  t.isFloat = true;
  t.isSigned = true;
  return t;
}
 
template <typename T> constexpr bool TypeTraits::isSimpleType() {
  return std::is_integral<T>::value || std::is_floating_point<T>::value;
}
 
template <> constexpr bool TypeTraits::isSimpleType<IeeeHalf>() { return true; }
 
template <> constexpr bool TypeTraits::isSimpleType<Quarter>() { return true; }
 
template <typename T> constexpr bool TypeTraits::requiresMetadata() {
  return false;
}
 
template <> constexpr bool TypeTraits::requiresMetadata<Quarter>() {
  return true;
}
 
} // end namespace poplar
 
#endif // poplar_TypeTraits_hpp