Sprout/sprout/math/rem_quo.hpp
2019-01-07 17:47:17 +09:00

145 lines
6.3 KiB
C++

/*=============================================================================
Copyright (c) 2011-2019 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_REM_QUO_HPP
#define SPROUT_MATH_REM_QUO_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/signbit.hpp>
#include <sprout/math/fabs.hpp>
#include <sprout/math/ilogb.hpp>
#include <sprout/math/scalbn.hpp>
#include <sprout/type_traits/enabler_if.hpp>
#include <sprout/type_traits/float_promote.hpp>
#include <sprout/utility/pair/pair.hpp>
namespace sprout {
namespace math {
namespace detail {
template<typename R, typename FloatType, typename Pair>
inline SPROUT_CONSTEXPR sprout::pair<FloatType, R>
rem_quo_ret(Pair const& p) {
typedef sprout::pair<FloatType, R> type;
return type(static_cast<FloatType>(p.first), p.second);
}
template<typename R, typename T>
inline SPROUT_CONSTEXPR sprout::pair<T, R>
rem_quo_impl_7(T x, T y, int k, R iquo, T x1, T z) {
typedef sprout::pair<T, R> type;
return (z > y) || ((z == y) && ((iquo & 1) != 0))
? x < 0 ? type(-(x1 - y), ((iquo + 1) & 0x7) * k) : type(x1 - y, ((iquo + 1) & 0x7) * k)
: x < 0 ? type(-x1, (iquo & 0x7) * k) : type(x1, (iquo & 0x7) * k)
;
}
template<typename R, typename T>
inline SPROUT_CONSTEXPR sprout::pair<T, R>
rem_quo_impl_6(T x, T y, int k, R iquo, T x1) {
return x1 >= y
? sprout::math::detail::rem_quo_impl_7(x, y, k, iquo + 1, x1 - y, (x1 - y) + (x1 - y))
: sprout::math::detail::rem_quo_impl_7(x, y, k, iquo, x1, x1 + x1)
;
}
template<typename R, typename T>
inline SPROUT_CONSTEXPR sprout::pair<T, R>
rem_quo_impl_5(T x, T y, int k, R iquo, T x1, T y1, T z, int iscy, int idiff, int i) {
return i != idiff
? z >= 0
? sprout::math::detail::rem_quo_impl_5(x, y, k, iquo + iquo + 2, z + z, y1, z + z - y1, iscy, idiff, i + 1)
: sprout::math::detail::rem_quo_impl_5(x, y, k, iquo + iquo, x1 + x1, y1, x1 + x1 - y1, iscy, idiff, i + 1)
: sprout::math::detail::rem_quo_impl_6(x, y, k, iquo, sprout::math::scalbn(x1, iscy))
;
}
template<typename R, typename T>
inline SPROUT_CONSTEXPR sprout::pair<T, R>
rem_quo_impl_4(T x, T y, int k, R iquo, T x1, T y1, int iscy, int idiff, int i) {
return sprout::math::detail::rem_quo_impl_5(x, y, k, iquo, x1, y1, x1 - y1, iscy, idiff, i);
}
template<typename R, typename T>
inline SPROUT_CONSTEXPR sprout::pair<T, R>
rem_quo_impl_3(T x, T y, int k, R iquo, T x1, int iscx, int iscy, int idiff) {
return idiff < 0 ? sprout::math::detail::rem_quo_impl_7(x, y, k, iquo, x1, x1 + x1)
: idiff ? sprout::math::detail::rem_quo_impl_4(x, y, k, iquo, sprout::math::scalbn(x1, -iscx), sprout::math::scalbn(y, -iscy), iscy, idiff, 0)
: sprout::math::detail::rem_quo_impl_6(x, y, k, iquo, x1)
;
}
template<typename R, typename T>
inline SPROUT_CONSTEXPR sprout::pair<T, R>
rem_quo_impl_2(T x, T y, int k, R iquo, T x1, int iscx, int iscy) {
return sprout::math::detail::rem_quo_impl_3(x, y, k, iquo, x1, iscx, iscy, iscx - iscy);
}
template<typename R, typename T>
inline SPROUT_CONSTEXPR sprout::pair<T, R>
rem_quo_impl_1(T x, T y, int k, R iquo, T x1) {
return sprout::math::detail::rem_quo_impl_2(x, y, k, iquo, x1, sprout::math::ilogb(x1), sprout::math::ilogb(y));
}
template<typename R, typename T>
inline SPROUT_CONSTEXPR sprout::pair<T, R>
rem_quo_impl(T x, T y, R iquo) {
return sprout::math::detail::rem_quo_impl_1(x, sprout::math::fabs(y), (sprout::math::signbit(x) ^ sprout::math::signbit(y) ? -1 : 1), iquo, sprout::math::fabs(x));
}
} // namespace detail
//
// rem_quo
//
//
// issue:
// rem_quo(-NaN, -NaN) returns {-NaN, _} .
// # returns {+NaN, _} . ( same as rem_quo(+NaN, +NaN) )
//
template<
typename R = int,
typename FloatType,
typename sprout::enabler_if<std::is_floating_point<FloatType>::value && std::is_integral<R>::value>::type = sprout::enabler
>
inline SPROUT_CONSTEXPR sprout::pair<FloatType, R>
rem_quo(FloatType x, FloatType y) {
typedef sprout::pair<FloatType, R> type;
return y == 0 ? type(-sprout::numeric_limits<FloatType>::quiet_NaN(), R(0))
: sprout::math::isnan(y)
? sprout::math::isnan(x)
? type(sprout::math::signbit(y) && sprout::math::signbit(x) ? -sprout::numeric_limits<FloatType>::quiet_NaN() : sprout::numeric_limits<FloatType>::quiet_NaN(), R(0))
: type(y, R(0))
: sprout::math::isnan(x) ? type(x, R(0))
: x == sprout::numeric_limits<FloatType>::infinity() || x == -sprout::numeric_limits<FloatType>::infinity()
? type(-sprout::numeric_limits<FloatType>::quiet_NaN(), R(0))
: x == 0 ? type(x, R(0))
: y == sprout::numeric_limits<FloatType>::infinity() || y == -sprout::numeric_limits<FloatType>::infinity() ? type(x, R(0))
: sprout::math::detail::rem_quo_ret<R, FloatType>(sprout::math::detail::rem_quo_impl(
static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(x),
static_cast<typename sprout::math::detail::float_compute<FloatType>::type>(y),
R(0)
))
;
}
template<
typename R = int,
typename ArithmeticType1,
typename ArithmeticType2,
typename sprout::enabler_if<
std::is_arithmetic<ArithmeticType1>::value && std::is_arithmetic<ArithmeticType2>::value && std::is_integral<R>::value
>::type = sprout::enabler
>
inline SPROUT_CONSTEXPR sprout::pair<
typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type,
R
>
rem_quo(ArithmeticType1 x, ArithmeticType2 y) {
typedef typename sprout::float_promote<ArithmeticType1, ArithmeticType2>::type type;
return sprout::math::rem_quo(static_cast<type>(x), static_cast<type>(y));
}
} // namespace math
using sprout::math::rem_quo;
} // namespace sprout
#endif // #ifndef SPROUT_MATH_REM_QUO_HPP