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| author | Andi Kleen <ak@suse.de> | 2006-09-26 10:52:38 +0200 |
|---|---|---|
| committer | Andi Kleen <andi@basil.nowhere.org> | 2006-09-26 10:52:38 +0200 |
| commit | 0136611c62e8650e354b95c76dff6d2ce6030eff (patch) | |
| tree | 9ba66105bccc4d83b84663b8dda7e51962c22a04 /include/asm-i386 | |
| parent | 8380aabb99719af583447133f19a4d8074b5c337 (diff) | |
| download | lwn-0136611c62e8650e354b95c76dff6d2ce6030eff.tar.gz lwn-0136611c62e8650e354b95c76dff6d2ce6030eff.zip | |
[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>
Diffstat (limited to 'include/asm-i386')
0 files changed, 0 insertions, 0 deletions