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Subject: Re: Integer or Floating Point for Scoring?

Author: Robert Hyatt

Date: 05:58:55 02/09/99

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On February 09, 1999 at 02:43:52, Larry Griffiths wrote:

>I have been using Floating point (double) for my evaluation (scoring)
>function.  I set some variables to 0.0 when starting the Alpha-Beta search.
>I add values to these variables when a move is made and then subtract them
>back out when restoreing the piece.  I have found that the result is not
>always returned back to 0.0.  I get something like 3.56234567343534-18.
>
>Should I be using integers for scoring instead?
>
>Thanks in advance!   :->
>
>Larry


there are two reasons to use FP scoring.  On some machines, FP is faster
than integers.  IE on the Cray using a floating point doesn't hurt.  On the
intel, it frees up a register since you can keep the eval in an FP register
rather than tying up eax or whatever.  This might make it worthwhile.  Since
the newer intel machines do floating point adds in parallel with the other
instructions, the somewhat slower time might not be a problem.

best advice:  test it.  not hard to replace 'float' with 'int' and recompile
and test.



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