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| author | Frederic Weisbecker <fweisbec@gmail.com> | 2010-05-12 23:19:01 +0200 |
|---|---|---|
| committer | Frederic Weisbecker <fweisbec@gmail.com> | 2010-05-12 23:20:33 +0200 |
| commit | a9aa1d02de36b450990b0e25a88fc2ff1c3e6b94 (patch) | |
| tree | 1f9d19f1642d263e65906a916a48be9339accc73 /lib/hweight.c | |
| parent | nmi_watchdog: Tell the world we're active (diff) | |
| parent | Linux 2.6.34-rc7 (diff) | |
| download | linux-a9aa1d02de36b450990b0e25a88fc2ff1c3e6b94.tar.xz linux-a9aa1d02de36b450990b0e25a88fc2ff1c3e6b94.zip | |
Merge commit 'v2.6.34-rc7' into perf/nmi
Merge reason: catch up with latest softlockup detector changes.
Diffstat (limited to 'lib/hweight.c')
| -rw-r--r-- | lib/hweight.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/lib/hweight.c b/lib/hweight.c index 389424ecb129..63ee4eb1228d 100644 --- a/lib/hweight.c +++ b/lib/hweight.c @@ -11,11 +11,18 @@ unsigned int hweight32(unsigned int w) { +#ifdef ARCH_HAS_FAST_MULTIPLIER + w -= (w >> 1) & 0x55555555; + w = (w & 0x33333333) + ((w >> 2) & 0x33333333); + w = (w + (w >> 4)) & 0x0f0f0f0f; + return (w * 0x01010101) >> 24; +#else 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; +#endif } EXPORT_SYMBOL(hweight32); |