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/* popcount.c
*
* popcount() replacement function for systems that don't provide their own.
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "config.h"
#include "wsutil/popcount.h"
int
popcount(unsigned int mask)
{
#if (__GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 4))
/* GCC 3.4 or newer */
return __builtin_popcount(mask);
#else
/* HACKMEM 169 */
unsigned long y;
y = (mask >> 1) &033333333333;
y = mask - y - ((y >>1) & 033333333333);
return (((y + (y >> 3)) & 030707070707) % 077);
#endif
}
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