Author: KarinsDad
Date: 07:55:45 12/05/99
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The problem is that some of us do not have access to 64 bit machines (at least I no longer have access to them). My method is similar to Alessandro's with 15 bytes to handle bishop and diagonal queen attacks and moves. The advantage of this for attacks is that you only have to check 1 of the 15 bytes out of each bitboard (actually, you only need 13 bytes, but my structures are currently set up as 16 bytes just for boundary convenience) per direction (2). The same for moves (I would like to use a system in the future of only creating those diagonal bitmaps that can possibly be used by either side and then only filling in a new byte in the structure as I go down the tree and move a bishop or queen). The disadvantage is that you have to figure out which 2 bytes to use, but I think you have a similar issue with 64 bits (although I haven't studied the Crafty code to figure it out). What I haven't figured out from Alessandro's system yet is why he needs such large bitboard structures (64 * 256). KarinsDad :)
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