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Subject: Re: SSE2 bit[64] * byte[64] dot product

Author: Fabien Letouzey

Date: 08:35:10 07/19/04

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On July 19, 2004 at 10:59:05, Anthony Cozzie wrote:

>32 cycles is _really_ good.  I think that on average rotated bitboard attack
>generation is 20 cycles, so that is 50 cycles / piece / mobility = 500 cycles
>(~250 ns on my computer) for all pieces, which is really not bad.  In fact, 32
>cycles is not that much slower than popcount!

>anthony

Why would it be?  Maybe I misunderstand the calculation but it seems to me that
a table-based solution, similar to one for popcount, would also do the work?!

I am not saying that it would be better than Gerd's code, but my point is that I
would expect that there is a solution mearly as fast as a general popcount (not
one specific for sparse boards).

Fabien.




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