Author: blass uri
Date: 09:22:05 12/03/99
1)I am interested to know if bitboards help to do programs faster relative to
arrays of attack.
I started to try to write a chess program and
I think to use arrays like rookattack[i]-the number of the attacking rooks of
square i and I am interested to know if there is a way to be faster by
bitboards.
2)I found this piece of code in crafty at evaluate.c
if (WhiteBishops) {
if (WhiteBishops&mask_A7H7) {
if (WhiteBishops&SetMask(A7) && SetMask(B6)&BlackPawns)
score-=BISHOP_TRAPPED;
else if (WhiteBishops&SetMask(H7) && SetMask(G6)&BlackPawns)
score-=BISHOP_TRAPPED;
}
}
a)is it possible to save time by avoiding the first line
if (WhiteBishops)?
b)I guess that whitebishops is a 64 digits number and that this number gets 1
for every square with a white bishop.
I guess that mask_a7h7 gets 1 only for WhiteBishops at a7 or h7 and that the
other 62 digits of it are 0
Am I right?
c)what do the 64 bit numbers SetMask(A7),Setmask(B6) mean?
d)Do bitboards help to evaluate the trapped bishop faster relative to evaluating
the same information without bitboards?
Uri
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.