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Subject: Re: sliding attacks in three #define

Author: rasjid chan

Date: 11:49:28 04/09/04

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On April 09, 2004 at 14:32:43, Sune Fischer wrote:

>On April 09, 2004 at 02:30:36, rasjid chan wrote:
>
>>
>>
>>I have a set of simple macros for bitboard operations and they are meant for
>>those with a new chess program and like to implement fast complete
>>attacks by bishops and rooks. It is basically just three #define and all sliding
>>attacks would then be available for use in evaluations and move ordering. Of
>>course it is only when we don't yet count instruction cycles,
>>but then after things are moving we could EASILY upgrade to
>>rotated bitboards.
>
>If speed is not an issue, have you considered to use fillers directly?
>

>These are pretty handy to have around for other things, especially fillup and
>filldown is something I use a lot.
>
>-S.

I don't know exactly, but i guess there are not many variations or optimizations
possible for bitwise operations on bitboards. I did read
earlier threats that discuss ray extentions and cutoff and that's
what I use from commonsense.

I incrementally update two full king attack-map as if they are queens.
Although costly, just like attack-tables, they have many uses in many places.
So if a move cut a ray I have a cut() and when a move leave a ray, I have
an extend(). I basically use the same technique as in the examples I post.

Rasjid
















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