Author: Robert Hyatt
Date: 14:25:04 06/27/02
Go up one level in this thread
On June 27, 2002 at 17:24:00, Robert Hyatt wrote: >On June 26, 2002 at 09:20:03, Daniel Clausen wrote: > >>On June 26, 2002 at 09:14:19, Russell Reagan wrote: >> >>>On June 26, 2002 at 04:50:00, Daniel Clausen wrote: >>> >>>>I don't follow your logic. Whether your move format includes the captured piece >>>>type or not, how does that help you to find out what piece sits on E6? >>> >>>I think he means that he uses the 64-word array so that he can convert a move to >>>a string. For example, if he had a move from g1 to f3 of the knight, how is he >>>going to convert that to "Nf3"? He would either have to search through all of >>>his bitboards to see which piece was being moved, or he could just use an array. >>>That is how I understand it, but I could be missing his point also. >>> >>>Russell >> >>But converting a move to a string is not time-critical at all, since it's only >>used to print out the PV and stuff like that. I can't imagine that Bob updates a >>64-word array during the search to print out the PV at the end in a microsecond >>faster. :) >> >>Sargon > > >No... I _really_ need to know what I am capturing. But mainly for move >ordering. I could use the Swap() function, but if I am capturing a queen with >a pawn, then no Swap() call is necessary since that wins at least 8 points of >material, and maybe 9. That's a good enough estimate to avoid the Swap() >calculation. > >But to do that, I need to know the moving piece, which I do since I generate >moves piece by piece. But I also need to know what I am capturing, and to find >that requires stomping thru 6 bitboards, one for each kind of opponent piece. >On a 32 bit machine, that is a bit inefficient. On a 64 bit machine, I would >probably re-think this and dump the 64 char board totally.... BTW, this is why I use PieceOnSquare() (a macro) everywhere. So that should I choose, it could be modifed to eliminate the board[sq] reference and instead check all the piece bitboards and return the right value...
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