/// @file grotto/gadgets/activations/softplus.hpp
/// @author Ryan Henry <ryan.henry@ucalgary.ca>
/// @brief Cleartext reference for `softplus`.
/// @copyright Copyright (c) 2019-2023 Ryan Henry and others
/// @license Released under a GNU General Public v2.0 (GPLv2) license;
///          see [LICENSE.md](@ref license) for details.

#ifndef LIBDPF_INCLUDE_GROTTO_GADGETS_ACTIVATIONS_SOFTPLUS_HPP__
#define LIBDPF_INCLUDE_GROTTO_GADGETS_ACTIVATIONS_SOFTPLUS_HPP__

#include <cmath>
#include <array>
#include <limits>

#include "grotto/gadget_hints.hpp"

namespace grotto
{

namespace gadgets
{

HEDLEY_DIAGNOSTIC_PUSH
HEDLEY_DIAGNOSTIC_DISABLE_DEPRECATED


static constexpr double softplus_default_beta = 1;
template <double const & beta = softplus_default_beta>
struct HEDLEY_DEPRECATED_FOR(2026, grotto::eval_window) softplus
{
    template <typename T>
    T operator()(T x)
    {
        if (x > 20) return x*beta;
        return (std::log1p(std::exp(beta*x)))/beta;
    }
};

template <double const & beta>
struct gadget_hints<softplus<beta>>
{
    static constexpr double min = std::numeric_limits<double>::min();
    static constexpr double max = std::numeric_limits<double>::max();
    static constexpr double poles[] = { };
    static constexpr double interesting_points[] = { 20 };
    static constexpr unsigned degree = 3;
    static constexpr bool has_canonical_representation = false;
    static constexpr double canonical_bounds[] = { };
    static constexpr std::array<double, degree+1> canonical_polys[] = { };
};

HEDLEY_DIAGNOSTIC_POP

}  // namespace gadgets

}  // namespace grotto

#endif  // LIBDPF_INCLUDE_GROTTO_GADGETS_ACTIVATIONS_SOFTPLUS_HPP__