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Subject: Re: Crafty profits little from Itanium and Opteron versus Commercials

Author: Sune Fischer

Date: 05:24:28 08/07/03

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On August 07, 2003 at 08:15:08, Uri Blass wrote:

>>Crafty is 64 bit prog, which means it's slow on 32 bit, even I have found that
>>doing a lookup is faster than shifting, I simply never do 1<<sq, I use a table
>>for that.
>
>I guess that it is only for 64 bits and if you have 32 bits number then it is
>better to do 1<<i when 0<=i<32 and not to use arrays.
>
>Correct?

If you can do the shift in 1 clock, then you can't go any faster, but 64 bit
shifts are slow on old 32 bit chips so the table becomes faster.

So for pure 64 bit you get fewer tables, faster and cleaner code.

-S.

>Uri



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