mirror of
https://github.com/bolero-MURAKAMI/Sprout.git
synced 2024-11-14 10:39:05 +00:00
87 lines
2.6 KiB
C++
87 lines
2.6 KiB
C++
/*=============================================================================
|
|
Copyright (c) 2011-2013 Bolero MURAKAMI
|
|
https://github.com/bolero-MURAKAMI/Sprout
|
|
|
|
Distributed under the Boost Software License, Version 1.0. (See accompanying
|
|
file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
|
|
=============================================================================*/
|
|
#ifndef SPROUT_MATH_TANH_HPP
|
|
#define SPROUT_MATH_TANH_HPP
|
|
|
|
#include <type_traits>
|
|
#include <sprout/config.hpp>
|
|
#include <sprout/limits.hpp>
|
|
#include <sprout/math/detail/config.hpp>
|
|
#include <sprout/math/detail/float_compute.hpp>
|
|
#include <sprout/math/isnan.hpp>
|
|
#include <sprout/math/exp.hpp>
|
|
#include <sprout/type_traits/enabler_if.hpp>
|
|
|
|
namespace sprout {
|
|
namespace math {
|
|
namespace detail {
|
|
#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
|
|
inline SPROUT_CONSTEXPR float
|
|
builtin_tanh(float x) {
|
|
return __builtin_tanhf(x);
|
|
}
|
|
inline SPROUT_CONSTEXPR double
|
|
builtin_tanh(double x) {
|
|
return __builtin_tanh(x);
|
|
}
|
|
inline SPROUT_CONSTEXPR long double
|
|
builtin_tanh(long double x) {
|
|
return __builtin_tanhl(x);
|
|
}
|
|
#endif
|
|
|
|
template<typename T>
|
|
inline SPROUT_CONSTEXPR T
|
|
tanh_impl_2(T t, T u) {
|
|
return (t - u) / (t + u);
|
|
}
|
|
template<typename T>
|
|
inline SPROUT_CONSTEXPR T
|
|
tanh_impl_1(T t) {
|
|
return sprout::math::detail::tanh_impl_2(t, T(1) / t);
|
|
}
|
|
template<typename T>
|
|
inline SPROUT_CONSTEXPR T
|
|
tanh_impl(T x) {
|
|
return sprout::math::detail::tanh_impl_1(sprout::math::exp(x));
|
|
}
|
|
} // namespace detail
|
|
//
|
|
// tanh
|
|
//
|
|
template<
|
|
typename FloatType,
|
|
typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
|
|
>
|
|
inline SPROUT_CONSTEXPR FloatType
|
|
tanh(FloatType x) {
|
|
return sprout::math::isnan(x) ? x
|
|
: x == sprout::numeric_limits<FloatType>::infinity() ? FloatType(1)
|
|
: x == -sprout::numeric_limits<FloatType>::infinity() ? FloatType(-1)
|
|
#if SPROUT_USE_BUILTIN_CMATH_FUNCTION
|
|
: sprout::math::detail::builtin_tanh(x)
|
|
#else
|
|
: x == 0 ? x
|
|
: static_cast<FloatType>(sprout::math::detail::tanh_impl(static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x)))
|
|
#endif
|
|
;
|
|
}
|
|
template<
|
|
typename IntType,
|
|
typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
|
|
>
|
|
inline SPROUT_CONSTEXPR double
|
|
tanh(IntType x) {
|
|
return sprout::math::tanh(static_cast<double>(x));
|
|
}
|
|
} // namespace math
|
|
|
|
using sprout::math::tanh;
|
|
} // namespace sprout
|
|
|
|
#endif // #ifndef SPROUT_MATH_TANH_HPP
|