forked from osmocom/wireshark
31 lines
670 B
C
31 lines
670 B
C
/* popcount.c
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*
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* popcount() replacement function for systems that don't provide their own.
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*
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* Wireshark - Network traffic analyzer
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* By Gerald Combs <gerald@wireshark.org>
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* Copyright 1998 Gerald Combs
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*
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* SPDX-License-Identifier: GPL-2.0+
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*/
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#include "config.h"
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#include "wsutil/popcount.h"
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int
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popcount(unsigned int mask)
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{
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#if (__GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4))
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/* GCC 3.4 or newer */
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return __builtin_popcount(mask);
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#else
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/* HACKMEM 169 */
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unsigned long y;
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y = (mask >> 1) &033333333333;
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y = mask - y - ((y >>1) & 033333333333);
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return (((y + (y >> 3)) & 030707070707) % 077);
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#endif
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}
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