1/* Copyright (C) 2007-2017 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <http://www.gnu.org/licenses/>. */
17
18#include <limits.h>
19#include <sched.h>
20
21
22int
23__sched_cpucount (size_t setsize, const cpu_set_t *setp)
24{
25 int s = 0;
26 const __cpu_mask *p = setp->__bits;
27 const __cpu_mask *end = &setp->__bits[setsize / sizeof (__cpu_mask)];
28
29 while (p < end)
30 {
31 __cpu_mask l = *p++;
32
33#ifdef POPCNT
34 s += POPCNT (l);
35#else
36 if (l == 0)
37 continue;
38
39# if LONG_BIT > 32
40 l = (l & 0x5555555555555555ul) + ((l >> 1) & 0x5555555555555555ul);
41 l = (l & 0x3333333333333333ul) + ((l >> 2) & 0x3333333333333333ul);
42 l = (l & 0x0f0f0f0f0f0f0f0ful) + ((l >> 4) & 0x0f0f0f0f0f0f0f0ful);
43 l = (l & 0x00ff00ff00ff00fful) + ((l >> 8) & 0x00ff00ff00ff00fful);
44 l = (l & 0x0000ffff0000fffful) + ((l >> 16) & 0x0000ffff0000fffful);
45 l = (l & 0x00000000fffffffful) + ((l >> 32) & 0x00000000fffffffful);
46# else
47 l = (l & 0x55555555ul) + ((l >> 1) & 0x55555555ul);
48 l = (l & 0x33333333ul) + ((l >> 2) & 0x33333333ul);
49 l = (l & 0x0f0f0f0ful) + ((l >> 4) & 0x0f0f0f0ful);
50 l = (l & 0x00ff00fful) + ((l >> 8) & 0x00ff00fful);
51 l = (l & 0x0000fffful) + ((l >> 16) & 0x0000fffful);
52# endif
53
54 s += l;
55#endif
56 }
57
58 return s;
59}
60