mirror of
https://github.com/bolero-MURAKAMI/Sprout.git
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48 lines
1.3 KiB
C++
48 lines
1.3 KiB
C++
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#ifndef SPROUT_BIT_POPCOUNT_HPP
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#define SPROUT_BIT_POPCOUNT_HPP
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#include <type_traits>
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#include <sprout/config.hpp>
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#include <sprout/type_traits/enabler_if.hpp>
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namespace sprout {
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namespace detail {
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# if SPROUT_USE_BUILTIN_BIT_OPERATION
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inline SPROUT_CONSTEXPR int
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popcount(unsigned n) {
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return __builtin_popcount(n);
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}
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inline SPROUT_CONSTEXPR int
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popcount(unsigned long n) {
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return __builtin_popcountl(n);
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}
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inline SPROUT_CONSTEXPR int
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popcount(unsigned long long n) {
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return __builtin_popcountll(n);
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}
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# endif
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template<typename T, typename sprout::enabler_if<std::is_unsigned<T>::value>::type = sprout::enabler>
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inline SPROUT_CONSTEXPR int
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popcount(T n) {
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return n == 0 ? 0
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: 1 + sprout::detail::popcount(static_cast<T>(n & (n - 1)))
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;
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}
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template<typename T, typename sprout::enabler_if<std::is_signed<T>::value>::type = sprout::enabler>
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inline SPROUT_CONSTEXPR int
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popcount(T n) {
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return sprout::detail::popcount(static_cast<typename std::make_unsigned<T>::type>(n));
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}
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} // namespace detail
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//
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// popcount
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//
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template<typename T, typename sprout::enabler_if<std::is_integral<T>::value>::type = sprout::enabler>
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inline SPROUT_CONSTEXPR int
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popcount(T n) {
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return sprout::detail::popcount(n);
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}
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} // namespace sprout
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#endif // #ifndef SPROUT_BIT_POPCOUNT_HPP
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