mirror of
https://github.com/bolero-MURAKAMI/Sprout.git
synced 2024-11-14 10:39:05 +00:00
62 lines
1.7 KiB
C++
62 lines
1.7 KiB
C++
/*=============================================================================
|
|
Copyright (c) 2011-2014 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_POPCOUNT_HPP
|
|
#define SPROUT_BIT_POPCOUNT_HPP
|
|
|
|
#include <type_traits>
|
|
#include <sprout/config.hpp>
|
|
|
|
namespace sprout {
|
|
namespace detail {
|
|
# if SPROUT_USE_BUILTIN_BIT_OPERATION
|
|
inline SPROUT_CONSTEXPR int
|
|
popcount(unsigned n) {
|
|
return __builtin_popcount(n);
|
|
}
|
|
inline SPROUT_CONSTEXPR int
|
|
popcount(unsigned long n) {
|
|
return __builtin_popcountl(n);
|
|
}
|
|
inline SPROUT_CONSTEXPR int
|
|
popcount(unsigned long long n) {
|
|
return __builtin_popcountll(n);
|
|
}
|
|
# endif
|
|
template<typename T>
|
|
inline SPROUT_CONSTEXPR typename std::enable_if<
|
|
std::is_unsigned<T>::value,
|
|
int
|
|
>::type
|
|
popcount(T n) {
|
|
return n == 0 ? 0
|
|
: 1 + sprout::detail::popcount(static_cast<T>(n & (n - 1)))
|
|
;
|
|
}
|
|
template<typename T>
|
|
inline SPROUT_CONSTEXPR typename std::enable_if<
|
|
std::is_signed<T>::value,
|
|
int
|
|
>::type
|
|
popcount(T n) {
|
|
return sprout::detail::popcount(static_cast<typename std::make_unsigned<T>::type>(n));
|
|
}
|
|
} // namespace detail
|
|
//
|
|
// popcount
|
|
//
|
|
template<typename T>
|
|
inline SPROUT_CONSTEXPR typename std::enable_if<
|
|
std::is_integral<T>::value,
|
|
int
|
|
>::type
|
|
popcount(T n) {
|
|
return sprout::detail::popcount(n);
|
|
}
|
|
} // namespace sprout
|
|
|
|
#endif // #ifndef SPROUT_BIT_POPCOUNT_HPP
|