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| author | Ulrich Drepper <drepper@redhat.com> | 2007-06-08 18:29:24 +0000 |
|---|---|---|
| committer | Ulrich Drepper <drepper@redhat.com> | 2007-06-08 18:29:24 +0000 |
| commit | 7d0e41cebe87f807c70c65b9b8cb001edca66465 (patch) | |
| tree | 7bc3921e4c7778fd578635d43025767c13b24081 /posix | |
| parent | 47779a7d3cdbbe02a9e060770e0069aa40a73267 (diff) | |
| download | glibc-7d0e41cebe87f807c70c65b9b8cb001edca66465.zip glibc-7d0e41cebe87f807c70c65b9b8cb001edca66465.tar.gz glibc-7d0e41cebe87f807c70c65b9b8cb001edca66465.tar.bz2 | |
(__sched_cpucount): Allow using special instruction for counting bits.
Diffstat (limited to 'posix')
| -rw-r--r-- | posix/sched_cpucount.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/posix/sched_cpucount.c b/posix/sched_cpucount.c index d7f6b7b..fd2687d 100644 --- a/posix/sched_cpucount.c +++ b/posix/sched_cpucount.c @@ -30,22 +30,26 @@ __sched_cpucount (size_t setsize, cpu_set_t *setp) if (l == 0) continue; -#if LONG_BIT > 32 +#ifdef POPCNT + s += POPCNT (l); +#else +# 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 +# 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 +# endif s += l; +#endif } return s; |