glibc/posix/sched_cpucount.c

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/* Copyright (C) 2007-2018 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <sched.h>
int
__sched_cpucount (size_t setsize, const cpu_set_t *setp)
{
int s = 0;
const __cpu_mask *p = setp->__bits;
const __cpu_mask *end = &setp->__bits[setsize / sizeof (__cpu_mask)];
while (p < end)
{
__cpu_mask l = *p++;
#ifdef POPCNT
s += POPCNT (l);
#else
if (l == 0)
continue;
_Static_assert (sizeof (l) == sizeof (unsigned int)
|| sizeof (l) == sizeof (unsigned long)
|| sizeof (l) == sizeof (unsigned long long),
"sizeof (__cpu_mask");
if (sizeof (__cpu_mask) == sizeof (unsigned int))
s += __builtin_popcount (l);
else if (sizeof (__cpu_mask) == sizeof (unsigned long))
s += __builtin_popcountl (l);
else
s += __builtin_popcountll (l);
#endif
}
return s;
}