mirror of
https://github.com/bolero-MURAKAMI/Sprout.git
synced 2024-11-29 01:03:45 +00:00
85 lines
3.4 KiB
C++
85 lines
3.4 KiB
C++
/*=============================================================================
|
|
Copyright (c) 2011-2016 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_FUNCTIONAL_HASH_DETAIL_HASH_FLOAT_HPP
|
|
#define SPROUT_FUNCTIONAL_HASH_DETAIL_HASH_FLOAT_HPP
|
|
|
|
#include <sprout/config.hpp>
|
|
#include <sprout/workaround/std/cstddef.hpp>
|
|
#include <sprout/limits.hpp>
|
|
#include <sprout/functional/hash/hash_fwd.hpp>
|
|
#include <sprout/math/fpclassify.hpp>
|
|
#include <sprout/math/ldexp.hpp>
|
|
#include <sprout/math/float2_sig_exp.hpp>
|
|
#include <sprout/detail/integer/static_log2.hpp>
|
|
|
|
namespace sprout {
|
|
namespace detail {
|
|
inline SPROUT_CONSTEXPR std::size_t
|
|
hash_float_combine(std::size_t seed, std::size_t value) {
|
|
return seed ^ (value + (seed << 6) + (seed >> 2));
|
|
}
|
|
|
|
template<typename T>
|
|
inline SPROUT_CONSTEXPR std::size_t
|
|
float_hash_value_impl_4(T v, int exp, std::size_t seed, std::size_t length, std::size_t i = 0) {
|
|
return i != length ? sprout::detail::float_hash_value_impl_4(
|
|
sprout::ldexp(v - static_cast<T>(static_cast<std::size_t>(v)), sprout::numeric_limits<std::size_t>::digits),
|
|
exp, sprout::detail::hash_float_combine(seed, static_cast<std::size_t>(v)),
|
|
length, i + 1
|
|
)
|
|
: sprout::detail::hash_float_combine(seed, exp)
|
|
;
|
|
}
|
|
template<typename T>
|
|
inline SPROUT_CONSTEXPR std::size_t
|
|
float_hash_value_impl_3(T v, int exp) {
|
|
return sprout::detail::float_hash_value_impl_4(
|
|
sprout::ldexp(v - static_cast<T>(static_cast<std::size_t>(v)), sprout::numeric_limits<std::size_t>::digits),
|
|
exp, static_cast<std::size_t>(v),
|
|
(sprout::numeric_limits<T>::digits * sprout::detail::static_log2<sprout::numeric_limits<T>::radix>::value + sprout::numeric_limits<std::size_t>::digits - 1)
|
|
/ sprout::numeric_limits<std::size_t>::digits
|
|
);
|
|
}
|
|
template<typename T>
|
|
inline SPROUT_CONSTEXPR std::size_t
|
|
float_hash_value_impl_2(T v, int exp) {
|
|
return sprout::detail::float_hash_value_impl_3(sprout::ldexp(v, sprout::numeric_limits<std::size_t>::digits), exp);
|
|
}
|
|
template<typename T, typename P>
|
|
inline SPROUT_CONSTEXPR std::size_t
|
|
float_hash_value_impl_1(P const& p) {
|
|
return ((p.first) < 0) ? sprout::detail::float_hash_value_impl_2(
|
|
-p.first, p.second + (sprout::numeric_limits<T>::max_exponent - sprout::numeric_limits<T>::min_exponent)
|
|
)
|
|
: sprout::detail::float_hash_value_impl_2(p.first, p.second)
|
|
;
|
|
}
|
|
template<typename T>
|
|
inline SPROUT_CONSTEXPR std::size_t
|
|
float_hash_value_impl(T v) {
|
|
return sprout::detail::float_hash_value_impl_1<T>(sprout::math::float2_sig_exp(v));
|
|
}
|
|
|
|
template<typename T>
|
|
inline SPROUT_CONSTEXPR std::size_t
|
|
float_hash_value_1(T v, int fp) {
|
|
return fp == FP_ZERO ? 0
|
|
: fp == FP_INFINITE ? std::size_t(v > 0 ? -1 : -2)
|
|
: fp == FP_NAN ? std::size_t(-3)
|
|
: sprout::detail::float_hash_value_impl(v)
|
|
;
|
|
}
|
|
template<typename T>
|
|
inline SPROUT_CONSTEXPR std::size_t
|
|
float_hash_value(T v) {
|
|
return sprout::detail::float_hash_value_1(v, sprout::fpclassify(v));
|
|
}
|
|
} // namespace detail
|
|
} // namespace sprout
|
|
|
|
#endif // #ifndef SPROUT_FUNCTIONAL_HASH_DETAIL_HASH_FLOAT_HPP
|