mirror of
https://github.com/bolero-MURAKAMI/Sprout
synced 2024-11-12 21:09:01 +00:00
99 lines
2.8 KiB
C++
99 lines
2.8 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_BIT_PARITY_HPP
|
|
#define SPROUT_BIT_PARITY_HPP
|
|
|
|
#include <climits>
|
|
#include <type_traits>
|
|
#include <sprout/config.hpp>
|
|
#include <sprout/workaround/std/cstddef.hpp>
|
|
#include <sprout/bit/shlr.hpp>
|
|
|
|
namespace sprout {
|
|
namespace detail {
|
|
# if SPROUT_USE_BUILTIN_BIT_OPERATION
|
|
inline SPROUT_CONSTEXPR int
|
|
parity(unsigned x) {
|
|
return __builtin_parity(x);
|
|
}
|
|
inline SPROUT_CONSTEXPR int
|
|
parity(unsigned long x) {
|
|
return __builtin_parityl(x);
|
|
}
|
|
inline SPROUT_CONSTEXPR int
|
|
parity(unsigned long long x) {
|
|
return __builtin_parityll(x);
|
|
}
|
|
# endif
|
|
template<std::size_t N, typename Integral>
|
|
inline SPROUT_CONSTEXPR typename std::enable_if<
|
|
(N == 1),
|
|
Integral
|
|
>::type
|
|
parity_bytes(Integral x) SPROUT_NOEXCEPT {
|
|
return x;
|
|
}
|
|
template<std::size_t N, typename Integral>
|
|
inline SPROUT_CONSTEXPR typename std::enable_if<
|
|
(N > 1),
|
|
Integral
|
|
>::type
|
|
parity_bytes(Integral x) SPROUT_NOEXCEPT {
|
|
return sprout::detail::parity_bytes<N / 2>(
|
|
x ^ sprout::shlr(x, N / 2 * CHAR_BIT)
|
|
);
|
|
}
|
|
template<typename Integral>
|
|
inline SPROUT_CONSTEXPR Integral
|
|
parity_bytes(Integral x) SPROUT_NOEXCEPT {
|
|
return sprout::detail::parity_bytes<sizeof(Integral)>(x);
|
|
}
|
|
template<typename Integral>
|
|
inline SPROUT_CONSTEXPR Integral
|
|
parity_bits4(Integral x) SPROUT_NOEXCEPT {
|
|
return x ^ sprout::shlr(x, 4);
|
|
}
|
|
template<typename Integral>
|
|
inline SPROUT_CONSTEXPR Integral
|
|
parity_bits2(Integral x) SPROUT_NOEXCEPT {
|
|
return sprout::detail::parity_bits4(
|
|
x ^ sprout::shlr(x, 2)
|
|
);
|
|
}
|
|
template<typename Integral>
|
|
inline SPROUT_CONSTEXPR Integral
|
|
parity_bits1(Integral x) SPROUT_NOEXCEPT {
|
|
return sprout::detail::parity_bits2(
|
|
x ^ sprout::shlr(x, 1)
|
|
);
|
|
}
|
|
template<typename Integral>
|
|
inline SPROUT_CONSTEXPR Integral
|
|
parity_bits(Integral x) SPROUT_NOEXCEPT {
|
|
return sprout::detail::parity_bits1(x);
|
|
}
|
|
template<typename Integral>
|
|
inline SPROUT_CONSTEXPR int
|
|
parity(Integral x) {
|
|
return static_cast<int>(sprout::detail::parity_bytes(sprout::detail::parity_bits(x))) & 1;
|
|
}
|
|
} // namespace detail
|
|
//
|
|
// parity
|
|
//
|
|
template<typename Integral>
|
|
inline SPROUT_CONSTEXPR typename std::enable_if<
|
|
std::is_integral<Integral>::value,
|
|
int
|
|
>::type
|
|
parity(Integral x) {
|
|
return sprout::detail::parity(x);
|
|
}
|
|
} // namespace sprout
|
|
|
|
#endif // #ifndef SPROUT_BIT_PARITY_HPP
|