mirror of
https://github.com/matrix-construct/construct
synced 2024-11-18 07:50:57 +01:00
58 lines
1.2 KiB
C
58 lines
1.2 KiB
C
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// Matrix Construct
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//
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// Copyright (C) Matrix Construct Developers, Authors & Contributors
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// Copyright (C) 2016-2021 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_MATH_LOG2_H
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namespace ircd::math
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{
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template<class Z> constexpr bool is_pow2(const Z);
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template<class Z> constexpr Z next_pow2(const Z);
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template<class Z> constexpr Z log2(const Z);
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template<class Z> constexpr Z sqr(const Z);
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}
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template<class Z>
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inline constexpr Z
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ircd::math::sqr(const Z n)
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{
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return pow(n, 2);
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}
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template<class Z>
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inline constexpr Z
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ircd::math::log2(const Z n)
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{
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return n > Z{1}?
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Z{1} + log2(n >> 1):
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0;
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}
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template<class Z>
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inline constexpr Z
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ircd::math::next_pow2(Z v)
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{
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--v;
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v |= v >> 1;
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v |= v >> 2;
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v |= v >> 4;
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v |= v >> 8;
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v |= v >> 16;
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v |= v >> 32;
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return ++v;
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}
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template<class Z>
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inline constexpr bool
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ircd::math::is_pow2(const Z v)
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{
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return v && !(v & (v - Z{1}));
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}
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