35 lines
1.2 KiB
C
35 lines
1.2 KiB
C
/*
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* Copyright (c) 2020 Hans Petter Selasky <hps@selasky.org>
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*
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* Permission to use, copy, modify, and 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 appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*/
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#pragma once
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#if defined(_MSC_VER) && defined(_M_X64)
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#include <intrin.h>
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#endif
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static inline uint64_t util_mul_div64(uint64_t num, uint64_t mul, uint64_t div)
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{
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#if defined(_MSC_VER) && defined(_M_X64)
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unsigned __int64 high;
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const unsigned __int64 low = _umul128(num, mul, &high);
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unsigned __int64 rem;
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return _udiv128(high, low, div, &rem);
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#else
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const uint64_t rem = num % div;
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return (num / div) * mul + (rem * mul) / div;
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#endif
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}
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