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| author | Arnaldo Carvalho de Melo <acme@redhat.com> | 2010-04-30 19:31:12 -0300 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2010-05-02 12:00:44 -0300 |
| commit | fb72014d98afd51e85aab9c061344ef32d615606 (patch) | |
| tree | 18713d4d1084870c604b512396b893944a2bbdab /tools/perf/util/hweight.c | |
| parent | bc4b473f1aa2ef785ccfd890a24a1de5a6660f98 (diff) | |
| download | kernel_samsung_espresso10-fb72014d98afd51e85aab9c061344ef32d615606.zip kernel_samsung_espresso10-fb72014d98afd51e85aab9c061344ef32d615606.tar.gz kernel_samsung_espresso10-fb72014d98afd51e85aab9c061344ef32d615606.tar.bz2 | |
perf tools: Don't use code surrounded by __KERNEL__
We need to refactor code to be explicitely shared by the kernel and at
least the tools/ userspace programs, so, till we do that, copy the bare
minimum bitmap/bitops code needed by tools/perf.
Reported-by: "H. Peter Anvin" <hpa@zytor.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util/hweight.c')
| -rw-r--r-- | tools/perf/util/hweight.c | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/tools/perf/util/hweight.c b/tools/perf/util/hweight.c new file mode 100644 index 0000000..5c1d0d0 --- /dev/null +++ b/tools/perf/util/hweight.c @@ -0,0 +1,31 @@ +#include <linux/bitops.h> + +/** + * hweightN - returns the hamming weight of a N-bit word + * @x: the word to weigh + * + * The Hamming Weight of a number is the total number of bits set in it. + */ + +unsigned int hweight32(unsigned int w) +{ + unsigned int res = w - ((w >> 1) & 0x55555555); + res = (res & 0x33333333) + ((res >> 2) & 0x33333333); + res = (res + (res >> 4)) & 0x0F0F0F0F; + res = res + (res >> 8); + return (res + (res >> 16)) & 0x000000FF; +} + +unsigned long hweight64(__u64 w) +{ +#if BITS_PER_LONG == 32 + return hweight32((unsigned int)(w >> 32)) + hweight32((unsigned int)w); +#elif BITS_PER_LONG == 64 + __u64 res = w - ((w >> 1) & 0x5555555555555555ul); + res = (res & 0x3333333333333333ul) + ((res >> 2) & 0x3333333333333333ul); + res = (res + (res >> 4)) & 0x0F0F0F0F0F0F0F0Ful; + res = res + (res >> 8); + res = res + (res >> 16); + return (res + (res >> 32)) & 0x00000000000000FFul; +#endif +} |