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/*!
    \file
    \brief Defines categories for floating point numbers for use in NVRTC-compiled code
*/

#pragma once

#include <cutlass/detail/helper_macros.hpp> // CUTLASS_HOST_DEVICE
#include <cutlass/platform/platform.h> // uint32_t
#if !defined(__CUDACC_RTC__)
#include <cstring> // std::memcpy
#endif

namespace cutlass {

///////////////////////////////////////////////////////////////////////////////////////////////////

// All floating-point numbers can be put in one of these categories.
enum  {
    FP_NAN =
# define FP_NAN 0
      FP_NAN,
    FP_INFINITE =
# define FP_INFINITE 1
      FP_INFINITE,
    FP_ZERO =
# define FP_ZERO 2
      FP_ZERO,
    FP_SUBNORMAL =
# define FP_SUBNORMAL 3
      FP_SUBNORMAL,
    FP_NORMAL =
# define FP_NORMAL 4
      FP_NORMAL
};

CUTLASS_HOST_DEVICE
int fpclassify(float const& f) {

  uint32_t s;

  #if defined(__CUDA_ARCH__)
  s = reinterpret_cast<uint32_t const &>(f);
  #else
  std::memcpy(&s, &f, sizeof(s));
  #endif

  uint32_t exp      = s & 0x7f800000;
  uint32_t mantissa = s & 0x007fffff;

  if (exp == 0x7f800000) {
    if (mantissa) {
      return FP_NAN;
    }
    else {
      return FP_INFINITE;
    }
  }
  else if (!exp) {
    if (mantissa) {
      return FP_SUBNORMAL;
    }
    else {
      return FP_ZERO;
    }
  }
  return FP_NORMAL;
}

///////////////////////////////////////////////////////////////////////////////////////////////////

} // namespace cutlass

///////////////////////////////////////////////////////////////////////////////////////////////////