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/*! \file
    \brief Reference implementation for GEMM in host-side code.
*/
#pragma once

#include "cutlass/cutlass.h"
#include "cutlass/array.h"

namespace cutlass {
namespace reference {
namespace detail {

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

/// Template function to compute an inner product.
#pragma hd_warning_disable  // Suppresses warnings when attempting to
                            // instantiate with a host-only type
template <typename Atype, typename Btype, typename Ctype>
CUTLASS_HOST_DEVICE Ctype inner_product(Atype a, Btype b, Ctype c) {
    return Ctype(a) * Ctype(b) + c;
}

/// Specialization for matrix multiplication with binary operands
template <>
CUTLASS_HOST_DEVICE int
inner_product<Array<bin1_t, 32>, Array<bin1_t, 32>, int>(Array<bin1_t, 32> a,
                                                         Array<bin1_t, 32> b,
                                                         int c) {
    int accum = 0;
    for (int bit = 0; bit < 32; bit++) {
        accum += a[bit] ^ b[bit];
    }
    return accum + c;
}

/*
/// Specialization for matrix multiplication with signed 4-bit integer operands
template <>
CUTLASS_HOST_DEVICE
int inner_product<Array<int4b_t, 8>, Array<int4b_t, 8>, int>(
    Array<int4b_t, 8> a,
    Array<int4b_t, 8> b,
    int c) {

  int accum = 0;
  for (int k = 0; k < 8; k++) {
    accum += a[k] * b[k];
  }
  return accum + c;
}

/// Specialization for matrix multiplication with unsigned 4-bit integer
operands template <> CUTLASS_HOST_DEVICE int inner_product<Array<uint4b_t, 8>,
Array<uint4b_t, 8>, int>( Array<uint4b_t, 8> a, Array<uint4b_t, 8> b, int c) {

  int accum = 0;
  for (int k = 0; k < 8; k++) {
    accum += a[k] * b[k];
  }
  return accum + c;
}
*/

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

template <typename SrcType, typename DstType>
struct Cast {
    // Default behavior: convert to the destination type
#pragma hd_warning_disable  // Suppresses warnings when attempting to
                            // instantiate complex<T> with a host-only type
    CUTLASS_HOST_DEVICE
    static DstType apply(SrcType src) { return static_cast<DstType>(src); };
};

template <>
struct Cast<float, int8_t> {
    CUTLASS_HOST_DEVICE
    static int8_t apply(float src) {
        // Clamp to the range of signed 8-bit integers.
        return static_cast<int8_t>(fmaxf(-128.f, fminf(127.f, src)));
    };
};

template <>
struct Cast<float, uint8_t> {
    CUTLASS_HOST_DEVICE
    static uint8_t apply(float src) {
        // Clamp to the range of signed 8-bit integers.
        return static_cast<uint8_t>(fmaxf(0.f, fminf(255.f, src)));
    };
};

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

}  // namespace detail
}  // namespace reference
}  // namespace cutlass
