| commit | 0136611c62e8650e354b95c76dff6d2ce6030eff | [log] [tgz] |
|---|---|---|
| author | Andi Kleen <ak@suse.de> | Tue Sep 26 10:52:38 2006 +0200 |
| committer | Andi Kleen <andi@basil.nowhere.org> | Tue Sep 26 10:52:38 2006 +0200 |
| tree | 9ba66105bccc4d83b84663b8dda7e51962c22a04 | |
| parent | 8380aabb99719af583447133f19a4d8074b5c337 [diff] |
[PATCH] optimize hweight64 for x86_64 Based on patch from David Rientjes <rientjes@google.com>, but changed by AK. Optimizes the 64-bit hamming weight for x86_64 processors assuming they have fast multiplication. Uses five fewer bitops than the generic hweight64. Benchmark on one EMT64 showed ~25% speedup with 2^24 consecutive calls. Define a new ARCH_HAS_FAST_MULTIPLIER that can be set by other architectures that can also multiply fast. Signed-off-by: Andi Kleen <ak@suse.de>