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-rw-r--r--posix/sched_cpucount.c52
1 files changed, 52 insertions, 0 deletions
diff --git a/posix/sched_cpucount.c b/posix/sched_cpucount.c
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+/* 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;
+}