From: Andi Kleen Date: Tue, 26 Sep 2006 08:52:38 +0000 (+0200) Subject: [PATCH] optimize hweight64 for x86_64 X-Git-Tag: v2.6.19-rc1~1077^2~62 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0136611c62e8650e354b95c76dff6d2ce6030eff;p=pandora-kernel.git [PATCH] optimize hweight64 for x86_64 Based on patch from David Rientjes , 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 --- Reading git-diff-tree failed