Author: Tom Kerrigan
Date: 12:52:53 06/20/00
Go up one level in this thread
On June 20, 2000 at 15:03:48, Robert Hyatt wrote: >On June 20, 2000 at 14:07:39, Tom Kerrigan wrote: > >>On June 19, 2000 at 21:32:56, Robert Hyatt wrote: >> >>>On June 19, 2000 at 20:50:11, John Coffey wrote: >>> >>>>On June 19, 2000 at 19:48:36, Larry Griffiths wrote: >>>> >>>>>I have found bitboards to be an even trade-off on my Pentium system. I have to >>>>>update about 6 bitboards when a piece moves and this generates a lot of >>>>>instructions. I get it back in my IsKingInCheck code so it evens out. I like >>>>>to have fast move generation code, but most of my gains have been through >>>>>alpha-beta, hash-table, killer-move and movelist ordering etc. >>>>> >>>>>Larry. >>>> >>>> >>>>Maybe I am too much of a novice, but I don't see yet why I should convert over >>>>to bitboards. Is move generation faster? If so, why? My program scans the >>>>board and uses simple loops to generate moves. Do you not have to do loops >>>>with bitboards? >>> >>>Not to generate moves, No. You generate all the sliding piece moves with two >>>table lookups... >> >>Hmmm. I do table lookups all over my program, and none of them seem to be >>generating any moves... >>The fact is that you DO need to loop to generate moves in a bitboard program. >>Maybe it's not the same loop, but it's still a loop. >> >>-Tom > > >Who says so? Ask the Dark Thought guys. >Or Slate/Atkin. You only need to loop if you want to take the attack bitmap >and turn it into a list of moves. This is not the way _all_ programs operate >(chess 4.x, Dark Thought, others, any of which generate a few moves at a time, >then take one and search it, without enumerating the other moves.) > >So loops are something you do (with bitmaps) if you want to, not because you >have to. > >As far as your table lookups not generating any moves, that is a programming >issue. Mine do. :) Maybe your makemove() function can take bitboards as input (i.e., here is a set of squares that my pieces can move to) but mine sure can't. -Tom
This page took 0.02 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.