mirror of
https://github.com/matrix-construct/construct
synced 2024-05-15 17:33:46 +02:00
60 lines
1.4 KiB
C++
60 lines
1.4 KiB
C++
// The Construct
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//
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// Copyright (C) The Construct Developers, Authors & Contributors
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// Copyright (C) 2016-2023 Jason Volk <jason@zemos.net>
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//
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// Permission to use, copy, modify, and/or distribute this software for any
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// purpose with or without fee is hereby granted, provided that the above
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// copyright notice and this permission notice is present in all copies. The
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// full license for this software is available in the LICENSE file.
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#pragma once
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#define HAVE_IRCD_UTIL_POPCOUNT_H
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namespace ircd {
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inline namespace util
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{
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template<class T>
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constexpr int popcount(const T) noexcept;
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template<> constexpr int popcount(const unsigned long long) noexcept;
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template<> constexpr int popcount(const unsigned long) noexcept;
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template<> constexpr int popcount(const unsigned int) noexcept;
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}}
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template<>
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constexpr int
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ircd::util::popcount(const unsigned long long a)
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noexcept
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{
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#if __has_feature(__cpp_lib_bitops)
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return std::popcount(a);
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#else
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return __builtin_popcountll(a);
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#endif
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}
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template<>
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constexpr int
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ircd::util::popcount(const unsigned long a)
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noexcept
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{
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#if __has_feature(__cpp_lib_bitops)
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return std::popcount(a);
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#else
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return __builtin_popcountl(a);
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#endif
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}
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template<>
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constexpr int
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ircd::util::popcount(const unsigned int a)
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noexcept
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{
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#if __has_feature(__cpp_lib_bitops)
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return std::popcount(a);
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#else
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return __builtin_popcount(a);
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#endif
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}
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