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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
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#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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