Author mark.dickinson
Recipients fredrikj, loewis, mark.dickinson, rhettinger, terry.reedy, vstinner
Date 2008-12-13.13:10:05
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Message-id <1229173826.77.0.369626353113.issue3439@psf.upfronthosting.co.za>
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Content
Three files:
(1) bit_length7.patch just does the numbits->bit_length renaming;
    otherwise it's the same as numbits-6b.patch.
(2) bit_length7_opt.patch uses the fast bitcount method that Raymond
    pointed out.
(3) bit_length_pybench.patch adds a test for bit_length to pybench.

On my system (OS X 10.5.5/Core 2 Duo), on a 32-bit non-debug build of 
the trunk, pybench is showing me a 4-5% speedup for the optimized 
version.

(I also tried a version that uses gcc's __builtin_clzl function;  this 
was around 10% faster than the basic version, but of course it's not 
portable.)
History
Date User Action Args
2008-12-13 13:10:26mark.dickinsonsetrecipients: + mark.dickinson, loewis, rhettinger, terry.reedy, vstinner, fredrikj
2008-12-13 13:10:26mark.dickinsonsetmessageid: <1229173826.77.0.369626353113.issue3439@psf.upfronthosting.co.za>
2008-12-13 13:10:10mark.dickinsonlinkissue3439 messages
2008-12-13 13:10:10mark.dickinsoncreate