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Subject: Re: Bitboard question

Author: Russell Reagan

Date: 09:58:58 05/25/02

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On May 25, 2002 at 09:49:50, Gian-Carlo Pascutto wrote:

>On May 25, 2002 at 09:32:58, Russell Reagan wrote:
>
>>The problem is that you
>>have pseudo-attacks.
>
>No
>
>>Again, this seems like you could calculate pseudo-mobility,
>
>No
>
>You pick the right bitboard depending on the occupation of
>a rank/file/diagonal.
>
>You need to calculate bitboards in advance for every possible
>occupation of rank/file/diagonal.
>
>--
>GCP

I realize that you have to calculate the occupation of the rank/file/diagonal,
but calculating the occupation of the rank/file/diagonal involves ray tracing
just like it would in a non-bitboard approach.

So for non-bitboard approach, the steps would be:

1. ray trace

And for bitboards, the steps would be:

1. ray trace
2. array lookup
3. AND operation

So I still do not see how this could possibly be faster. Even after this, you
can't calculate absolute attacks or mobility, unless there is some method
someone would like to describe.

So, I still don't get it obviously.

Russell



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