Author: Uri Blass
Date: 02:16:49 05/05/04
Go up one level in this thread
On May 05, 2004 at 05:06:43, Daniel Shawul wrote: >On May 05, 2004 at 05:01:55, Uri Blass wrote: > >>On May 05, 2004 at 04:40:43, Andrew Williams wrote: >> >>>On May 05, 2004 at 03:03:15, Daniel Shawul wrote: >>> >>>>Hello >>>> >>>>Is incremental attack table slower than creating them on fly? >>>>I have both versions working properly right now but the incremental >>>>one further drops NPS by 30% , though InCheck and Checks are for free in this >>>>case. Anybody have similar experience? I am sure i have made no mistake in >>>>updating because i checked it with the known perft positions and node count is >>>>perfect. >>>> >>>>best >>>>daniel >>> >>>It's a very long time since I implemented them, but at the time I compared the >>>incremental ones were faster. I can't remember exactly how much faster it was, >>>but I think it was of the order of 10 to 15%, if only because that is what a >>>comment in an old source file says. What I don't know is if this was *after* >>>thorough debugging. >>> >>>Andrew >> >>I have different attack tables. >> >>Last time that I implemented incremental tables was a long time ago before I had >>a chess program. >> >>I did not make notes to see how much faster it was but it was more than being >>1000% faster in calculating perft. >> >>Uri > >How can incrementally updating attack tables make perft faster? I need the attack tables to generate legal moves. I have a function that generates the legal moves and it is dependent on the tables. My tables tell me if a square is attacked by the opponent so I do not generate moves that put the king in check. My tables also tell me the directions that a square is attacked and the square of the attacker from every direction so in case that the king is attacked I have a special function to generate moves that is using this information. I never had move generator that is not dependent on the tables and makemove always updated the tables. Uri
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