Author: Robert Hyatt
Date: 07:46:37 11/20/02
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On November 20, 2002 at 08:58:13, Kim Roper Jensen wrote: >Hi > >I just wondered, if we take an bitboard program and its evaluation function, and >then looked at all the bitmaps used/generated in it how many would be the same >?? > >What i wanted to know was, if there is any redundancy in the evaluation >bitboards, for example the same bitboard gets generated multiple times but in >different areas of evaluation. Not if the programmer knows what he is doing. But then, this is the same issue that faces non-bitboard programmers. you _never_ want to duplicate effort. It is wasted. > >My idea was something like this: > >I assume that every evaluation rule is dependant on 1 or more bitboards, so we >can say that a eval rule is dependant on 1 or more bitboards. > >Every evaluation rule that is used only 1 time gets scored first. >Every evaluation rule that uses 2 or more bitboards that the first rule has >generated >and so on. > >The trick should be that we only generate each bitboard once and then never >again and arrange code so we're using this fact. > >simple example with pawn eval: > >pawnBitBoard >> 8; all pawn moves 1 forward(or backward dependant on >orientation), but this can also be used to se if a pawn can interpose between an >attacker and defender. > >So instead of making clean easy readable code, we evaluate at once when we have >the bitboards that the rule is dependant of. > >With regards >Kim > >PS If this sounds like rubbish, theres a big chance it is, im not using >bitboards myself but like fiddling with stuff :) > >PPS If the start of the first PS is correct please dont flame me, im on work, >tired and almost drugged dead by coffe :)
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