Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Thoughts about board representations...

Author: Robert Hyatt

Date: 20:21:09 02/10/00

Go up one level in this thread


On February 10, 2000 at 22:03:24, Tom Kerrigan wrote:

>On February 10, 2000 at 17:50:54, Robert Hyatt wrote:
>
>>There are pros and cons for all implementations.  The pros for bitmaps don't
>>become apparent until they are run on a 'native' architecture (64 bit machines).
>>When all is said and done, it is likely that both approaches are going to end
>>up pretty much equal, except for the 'data width' problem.  IE an 0x88 program
>
>But you can look at the "data width" problem from the other direction: bitmaps
>don't run efficiently on non-64-bit processors.
>
>I like having a program that runs reasonably well on a small processor with
>small memory...
>
>-Tom


Two important points:  (1) 64 bits are the future, not 32 bits,  So in 5 years,
32 bits will probably be like 286's today.

(2) super-scalar architectures have a problem keeping both pipes full.  Bitmap
programs aren't as inefficient as first suspected, as they offer thousands of
places where two 32 bit and/or/xor/etc operations are needed to complete a 64
bit operation.  Super-scalar eats that alive and makes the penalty much less
than expected.  IE I'll bet a bitmap program actually executes 2 instructions
per clock way more than a non-bitmap program, which means part of the 'loss'
is covered by clever hardware...



This page took 0.01 seconds to execute

Last modified: Thu, 15 Apr 21 08:11:13 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.