diff options
Diffstat (limited to 'posix/sched_cpucount.c')
-rw-r--r-- | posix/sched_cpucount.c | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/posix/sched_cpucount.c b/posix/sched_cpucount.c new file mode 100644 index 0000000000..8404e8f3c0 --- /dev/null +++ b/posix/sched_cpucount.c @@ -0,0 +1,52 @@ +/* Copyright (C) 2007 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, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <limits.h> +#include <sched.h> + + +int +__sched_cpucount (cpu_set_t *setp) +{ + int s = 0; + for (unsigned int j = 0; j < __CPU_SETSIZE / __NCPUBITS; ++j) + { + __cpu_mask l = setp->__bits[j]; + if (l == 0) + continue; + +#if LONG_BIT > 32 + l = (l & 0x5555555555555555ul) + ((l >> 1) & 0x5555555555555555ul); + l = (l & 0x3333333333333333ul) + ((l >> 2) & 0x3333333333333333ul); + l = (l & 0x0f0f0f0f0f0f0f0ful) + ((l >> 4) & 0x0f0f0f0f0f0f0f0ful); + l = (l & 0x00ff00ff00ff00fful) + ((l >> 8) & 0x00ff00ff00ff00fful); + l = (l & 0x0000ffff0000fffful) + ((l >> 16) & 0x0000ffff0000fffful); + l = (l & 0x00000000fffffffful) + ((l >> 32) & 0x00000000fffffffful); +#else + l = (l & 0x55555555ul) + ((l >> 1) & 0x55555555ul); + l = (l & 0x33333333ul) + ((l >> 2) & 0x33333333ul); + l = (l & 0x0f0f0f0ful) + ((l >> 4) & 0x0f0f0f0ful); + l = (l & 0x00ff00fful) + ((l >> 8) & 0x00ff00fful); + l = (l & 0x0000fffful) + ((l >> 16) & 0x0000fffful); +#endif + + s += l; + } + + return s; +} |