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add popcount, clz, ctz

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bolero-MURAKAMI 2012-06-22 22:56:25 +09:00
parent ee8c952d05
commit 3500d0d49c
8 changed files with 181 additions and 38 deletions
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52
sprout/bit/clz.hpp Normal file
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#ifndef SPROUT_BIT_CLZ_HPP
#define SPROUT_BIT_CLZ_HPP
#include <climits>
#include <type_traits>
#include <sprout/config.hpp>
namespace sprout {
namespace detail {
# if SPROUT_USE_BUILTIN_BIT_OPERATION
inline SPROUT_CONSTEXPR int
clz(unsigned n) {
return __builtin_clz(n);
}
inline SPROUT_CONSTEXPR int
clz(unsigned long n) {
return __builtin_clzl(n);
}
inline SPROUT_CONSTEXPR int
clz(unsigned long long n) {
return __builtin_clzll(n);
}
# endif
template<typename T>
inline SPROUT_CONSTEXPR int
clz_impl(T n, T m = T(1) << (CHAR_BIT * sizeof(T) - 1)) {
return m == 0 || n & m ? 0
: 1 + sprout::detail::clz_impl(n, static_cast<T>(m >> 1))
;
}
template<typename T, typename sprout::enabler_if<std::is_unsigned<T>::value>::type = sprout::enabler>
inline SPROUT_CONSTEXPR int
clz(T n) {
return sprout::detail::clz_impl(static_cast<T>(n));
}
template<typename T, typename sprout::enabler_if<std::is_signed<T>::value>::type = sprout::enabler>
inline SPROUT_CONSTEXPR int
clz(T n) {
return sprout::detail::clz(static_cast<typename std::make_unsigned<T>::type>(n));
}
} // namespace detail
//
// clz
//
template<typename T, typename sprout::enabler_if<std::is_integral<T>::value>::type = sprout::enabler>
inline SPROUT_CONSTEXPR int
clz(T n) {
return sprout::detail::clz(n);
}
} // namespace sprout
#endif // #ifndef SPROUT_BIT_CLZ_HPP