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/*! \file
  \brief Functor performing linear combination with a maximum operation used by epilogues.
*/

#pragma once

#include <cutlass/array.h>
#include <cutlass/cutlass.h>
#include <cutlass/epilogue/thread/activation.h>
#include <cutlass/epilogue/thread/scale_type.h>
#include <cutlass/functional.h>
#include <cutlass/half.h>
#include <cutlass/numeric_conversion.h>
#include <cutlass/numeric_types.h>

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

namespace cutlass {
namespace epilogue {
namespace thread {

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

__forceinline__ __device__ float copysignf_pos(float a, float b)
{
    float r;
    r = __int_as_float(__float_as_int(a) | (__float_as_int(b) & 0x80000000));
    return r;
}

__forceinline__ __device__ float tanh_opt(float x)
{
#if (__CUDACC_VER_MAJOR__ < 11) || (__CUDA_ARCH__ < 750)
    const float exp_val = -1.f * fabs(2 * x);
    return copysignf_pos((1.0f - __expf(exp_val)) / (__expf(exp_val) + 1.0f), x);
#else
    return fast_tanh(x);
#endif
}

/////////////////////////////////////////////////////////////////////////////////////////////////
}  // namespace thread
}  // namespace epilogue
}  // namespace cutlass

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