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Subject: Re: 64 bits

Author: Robert Hyatt

Date: 17:53:14 06/20/02

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On June 20, 2002 at 18:56:24, Tom Kerrigan wrote:

>On June 20, 2002 at 17:59:13, Robert Hyatt wrote:
>
>>I don't disagree there to a point.  But in places like movegen, evaluate,
>>make/unmake, the majority of the things being fiddled with are 64 bit
>>values.
>
>You keep saying this, but I doubt it.
>
>For example, branches are typically 25% of code, and those aren't 64-bit.

not in movgen, for example...  and they are "bitless" so it really doesn't
matter for them.  I am talking about all the ands, ors, xors, shifts,
bsf's, bsr's, popcnts and the like.

>
>Nor are loop counters, if you have any loops. Or counters, period. Example: if
>you count how many pawns are on white squares. That's not 64-bit.

I have loop counters that are mainly 64 bit values.  I extract a bit, clear it,
and then test the entire thing at the bottom of the loop...


>
>Or, speaking of your eval function, your score isn't 64-bit. And presumably
>you're updating the score frequently. Your piece square tables aren't 64-bit.

The scores are updated, yes.  But only after significant numbers of boolean
operators are applied to the various chess bitmaps.  Those _trigger_ the
simple adds...



>
>I'd like to see actual data instead of handwaving.
>
>-Tom



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