Author: Inmann Werner
Date: 13:41:35 12/02/98
Analyzing my program, I found, that it spends most time in the routine detecting if the king is in check. I think, using Bitboard Representation will speed up a lot, and using Bitboards for this at the start will increase my learning. After some thinking and reading, I have some nice working routines but one big problem. I have a Bitboard with one Bit set to one, all others to zero. Now I want to know the number of the bit, counted from the "right side". Example: 64 should be 7 (or 6?) cause its the 7th (or 6th) bit. I programmed some routines which are more than bad. Is there a simple, but fast routine available? Please help! Second question. I will work with lookup tables. Cause I do not want to use rotated bitboards (at the beginning) I came to a "trick" for sliding figures. After some ANDs and ORs I know the Position of the king and the "attacking" rook for example. Now I have to find, if another figure blocks the attacking. With some other ANDs and XORs I have all possible "blockers" in a bitboard. Now I "AND" it with an attacktable which is defined as following. BITBOARD ATTACKTABLE[64][64]. In it are all BITBOARDS where all possible blocking Positions are in between the king and the attacking rook. Thats it. Is this a really bad idea? Any suggestions. Werner PS: I know, I "invite" old known things, but I want to understand what I do.
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