Author: Vincent Diepeveen
Date: 11:55:58 08/31/03
Go up one level in this thread
On August 30, 2003 at 18:05:01, Anthony Cozzie wrote: >On August 30, 2003 at 17:05:45, Vincent Diepeveen wrote: > >>In REBEL as we can read from its homepage it is also 1 instruction. >> >>Because Ed doesn't know the difference between C and BASIC, >>i'll write down the code for REBEL here in C (of course rebel-engine is 100% >>assembly so 'decompiling' is not happening here) >> >> attackers = MyAtt[sq] & 7; >> >>He that looks very similar to what i do in DIEP! >> >>Now fritz: >> >> attackers = MyAtt[sq] & 7; >> >>He HOW SIMILAR that looks to rebel? >> >>Must i go on? > >how is this incompatible with bitboards? I don't think there is some law saying It is incompatible because generating them with bitboards is going to be 6 times slower than without and that isn't a joke. Of course you can use a crippled bitboard version, so converting when having a bitboard with moves, the moves to a square and then one by one nail them in into the attacktable. Then you can limit the speed loss to a factor 3 perhaps. >you can't have bitboards *and* attack tables. I am giving very serious thought >to including Ed-style tables in Zappa. Crafty's king-safety code is (imo) >inadequate. With pieces like bishops, it trivially doesn't matter if the bishop >is at B1 or D3, it still is attacking the king's field. Maybe at some point >Zappa's bitboards will simply get phased out of existence, but I doubt it. I feel the crucial point is what type of code you use to generate moves, this will determine whether your program is a bitboarder or not. Because if you do that with bitboards, then your scanning code will be all bitboards too most likely. Even more likely you'll hardly have such scanning code (which the commercial engines have bigtime). >They >are simply too convenient for some things. There is many things which are said to be quick in bitboards which i already do for 8 years now in a different way just as quick, if not quicker. But by far the real reason why bitboards seem quick to some, is simply because they do not have all that fancy stuff the commercial guys have. If you don't have something you don't waste system time at it. with 99% sureness you can say then also that they won't show up at a world championship either. Last bitboarder i remember joining a world championship in person has been somewhere London2000 - James Robertson. Note that if i remember well he had written large parts in assembly. What a waste of time... >The rotated bitboard masks are L2 yes, but the others (like the k-p square) are >probably L1. > >anthony
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