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Subject: Re: "Using de Bruijn Sequences to Index a 1 in a Computer Word"

Author: Ricardo Gibert

Date: 02:03:32 02/12/02

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On February 11, 2002 at 20:23:08, Dann Corbit wrote:

>On February 09, 2002 at 12:53:32, Ricardo Gibert wrote:
>
>>On February 08, 2002 at 17:17:26, Oliver Roese wrote:
>>
>>>Hi!
>>>
>>>http://citeseer.nj.nec.com/338945.html
>>>Hope you find it interesting.
>>>
>>>Oliver
>>
>>Yes, it is quite interesting. Thanks!
>>
>>For 32 bits, the perfect hash function x%37 instead of the minimal perfect hash
>>function (x*debruijn32)>>27 also works well. The difference is a slightly larger
>>lookup table will be needed and a division is performed instead of a
>>multiplication plus a shift. For 64 bits the modulus 67 works.
>
>Have you made a 64 bit version?  I would be interested to know your benchmark
>results.

I have and have confirmed that "division is evil". The only thing going for it
is, it handles zero without any complication, but this is not enough.



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