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fix math: rounding function,etc...

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bolero-MURAKAMI 2013-02-10 11:54:54 +09:00
parent 53b99b25f8
commit 434aa8d3c5
22 changed files with 812 additions and 74 deletions
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142
sprout/math/logb2.hpp Normal file
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#ifndef SPROUT_MATH_LOGB2_HPP
#define SPROUT_MATH_LOGB2_HPP
#include <cstdint>
#include <type_traits>
#include <sprout/config.hpp>
#include <sprout/math/detail/config.hpp>
#include <sprout/type_traits/enabler_if.hpp>
#if SPROUT_FLT_RADIX_IS_2
# include <sprout/math/logb.hpp>
#else
# include <cstdint>
# include <sprout/detail/pow.hpp>
# include <sprout/math/log_a.hpp>
# include <sprout/math/trunc.hpp>
# include <sprout/math/itrunc.hpp>
#endif
namespace sprout {
namespace math {
namespace detail {
#if SPROUT_FLT_RADIX_IS_2
template<
typename FloatType,
typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
>
inline SPROUT_CONSTEXPR FloatType
logb2(FloatType x) {
return sprout::math::logb(x);
}
template<
typename IntType,
typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
>
inline SPROUT_CONSTEXPR double
logb2(IntType x) {
return sprout::math::logb(x);
}
#else
template<typename T>
inline SPROUT_CONSTEXPR T
logb2_impl_2_neg_lo(T x, T x0, T base, T exp) {
return base < 1 ? sprout::math::detail::logb2_impl_2_neg_lo(
x, x0 * 2, x / (x0 / 2), exp - 1
)
: exp
;
}
template<typename T>
inline SPROUT_CONSTEXPR T
logb2_impl_2_neg_hi(T x, T x0, T base, T exp) {
return !(base < 2) ? sprout::math::detail::logb2_impl_2_neg_hi(
x, x0 / 2, x / (x0 * 2), exp + 1
)
: exp
;
}
template<typename T>
inline SPROUT_CONSTEXPR T
logb2_impl_2_pos_lo(T x, T x0, T base, T exp) {
return base < 1 ? sprout::math::detail::logb2_impl_2_pos_lo(
x, x0 * 2, x / (x0 / 2), exp + 1
)
: exp
;
}
template<typename T>
inline SPROUT_CONSTEXPR T
logb2_impl_2_pos_hi(T x, T x0, T base, T exp) {
return !(base < 2) ? sprout::math::detail::logb2_impl_2_pos_hi(
x, x0 / 2, x / (x0 * 2), exp - 1
)
: exp
;
}
template<typename T>
inline SPROUT_CONSTEXPR T
logb2_impl_2(T x, T x0, T base, T exp) {
return exp < 0
? base < 1 ? sprout::math::detail::logb2_impl_2_neg_lo(
x, x0 * 2, x / (x0 / 2), exp - 1
)
: !(base < 2) ? sprout::math::detail::logb2_impl_2_neg_hi(
x, x0 / 2, x / (x0 * 2), exp + 1
)
: exp
: base < 1 ? sprout::math::detail::logb2_impl_2_pos_lo(
x, x0 * 2, x / (x0 / 2), exp + 1
)
: !(base < 2) ? sprout::math::detail::logb2_impl_2_pos_hi(
x, x0 / 2, x / (x0 * 2), exp - 1
)
: exp
;
}
template<typename T>
inline SPROUT_CONSTEXPR T
logb2_impl_1(T x, T x0, T exp) {
return sprout::math::detail::logb2_impl_2(x, x0, x / x0, exp);
}
template<typename T>
inline SPROUT_CONSTEXPR T
logb2_impl(T x, T exp) {
return sprout::math::detail::logb2_impl_1(
x, sprout::detail::pow_n(T(2), sprout::math::itrunc<std::intmax_t>(exp)), exp
);
}
template<
typename FloatType,
typename sprout::enabler_if<std::is_floating_point<FloatType>::value>::type = sprout::enabler
>
inline SPROUT_CONSTEXPR FloatType
logb2(FloatType x) {
return x < 0 ? sprout::math::detail::logb2_impl(
-x, sprout::math::trunc(sprout::math::log_a(FloatType(2), -x))
)
: sprout::math::detail::logb2_impl(
x, sprout::math::trunc(sprout::math::log_a(FloatType(2), x))
)
;
}
template<
typename IntType,
typename sprout::enabler_if<std::is_integral<IntType>::value>::type = sprout::enabler
>
inline SPROUT_CONSTEXPR double
logb2(IntType x) {
return sprout::math::detail::logb2(static_cast<double>(x));
}
#endif
} // namespace detail
using sprout::math::detail::logb2;
} // namespace math
using sprout::math::logb2;
} // namespace sprout
#endif // #ifndef SPROUT_MATH_LOGB2_HPP