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Subject: Re: To bitboard or not to bitboard?

Author: Jorge Pichard

Date: 12:09:16 08/31/03

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On August 31, 2003 at 14:57:28, Jorge Pichard wrote:

>On August 31, 2003 at 08:22:10, Tord Romstad wrote:
>
>>On August 31, 2003 at 08:03:48, Uri Blass wrote:
>>
>>>I have other questions.
>>>
>>>You say that the tables are not updated incrementally.
>>>I also remember that your evaluation is the most expensive part of
>>>your program.
>>>
>>>1)Do you update your attack tables after every move for things like better
>>>order of moves?
>>
>>Yes.  The tables are generated in the evaluation function (see my answer to
>>your second question below), and the evaluation function is called at all
>>nodes in the tree, before the moves are generated.
>>
>>>2)Do you consider the time of updating your attack tables as part of the
>>>time of your evaluation?


What if you use a transposition and pawn hash tables to reuse many previously
calculated results :-)


>>Yes, it is part of my evaluation function.  While I loop through all the
>>pieces and the squares they attack, I do various other things simultaneously
>>(like checking if a rook is on an open file or supports a passed pawn,
>>and assigning bonuses for that), in order to avoid having to loop more than
>>necessary.  Therefore I cannot easily move the attack table generation
>>out of the evaluation function without slowing things down.
>>
>>Tord
>
>
>What about 64-bit unsigned integers used as the board representation, they can
>be used for move generation as well without slowing it down too much. Or do
>they?
>
>Pichard



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