Search found 110 matches

by tvrzsky
Tue Apr 05, 2011 11:57 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: inline assembly -> Windows to Linux port
Replies: 4
Views: 850

Re: inline assembly -> Windows to Linux port

Oops, of course I meant:

Code: Select all

int LSBb(unsigned long long arg)
{
    if ((int)arg) return __builtin_ctz((arg));
    else return (__builtin_ctz((arg>>32))) + 32;
}
by tvrzsky
Tue Apr 05, 2011 11:24 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: inline assembly -> Windows to Linux port
Replies: 4
Views: 850

Re: inline assembly -> Windows to Linux port

Try this: int LSBssf(unsigned long long arg1) { int hword = (int)(arg1 >> 32); int retval; asm( "bsfl %1,%0 \n\t" "jnz 1f \n\t" "bsfl %2,%0 \n\t" "addl $32,%0 \n\t" "1: \n\t" : "=&q" (retval) :"m"(arg1),"q"(hword) : ); return retval; } Or...
by tvrzsky
Fri Mar 25, 2011 12:34 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: clang compiler
Replies: 18
Views: 3955

Re: clang compiler

Interesting, which version of gcc it is? And the build with no pgo was -O3? Any other options?
by tvrzsky
Thu Mar 24, 2011 1:40 am
Forum: Computer Chess Club: General Topics
Topic: Happy 80th birthday, Viktor Korchnoi! :)
Replies: 9
Views: 1740

Re: Happy 80th birthday, Viktor Korchnoi! :)

Tom Barrister wrote:Undoubtedly the strongest player in history to never win the (open) World Championship. Came within a whisker of winning in 1978. At the top of the game for over 50 years and still a force to be reckoned with today.
Don't forget about Paul Keres ...
by tvrzsky
Fri Jan 28, 2011 6:01 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Struggling with Alpha-Beta.
Replies: 7
Views: 1313

Re: Struggling with Alpha-Beta.

Your evaluateComputerMove function is not correct, let's change it this way: short evaluateComputerMove( unsigned long long board, int depth, int alpha, int beta ) { int i, value; unsigned long long new_board; short max = MIN_INFINITY-1; boards_checked++; /* The human (min) just mad...
by tvrzsky
Sat Mar 20, 2010 2:41 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Updating castling rights
Replies: 24
Views: 3773

Re: Updating castling rights

My engine is here in agreement with yours. 4k3/8/8/8/8/8/R7/R3K2R w KQ - 0 1 _______________________________ | |///| |///| |///| |///| | | | | |(k)| | | | |___|___|___|___|___|___|___|___| |///| |///| |///| |///| | | | | | | | | | | |___|___|___|___|___|___|___|___| | |///| |///| |///| |///|...
by tvrzsky
Tue Mar 16, 2010 10:37 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Hash Collision?
Replies: 82
Views: 8619

Re: Hash Collision?

My engines basical use method A, with the slight difference that they only adjust the negative scores. There is no need to adjust both; what is mate-in-N should become mate-in-(N+1) two ply earlier. So the score is only adjusted on one of the two plies. If you would adjust on both plies, some of th...
by tvrzsky
Tue Mar 16, 2010 7:52 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Hash Collision?
Replies: 82
Views: 8619

Re: Hash Collision?

Let me summarize again all important (in my eyes) about mate scores and their handling. Mate scores are completely different animal then usual scores (material + position) so we represent them usually as values close to some constant (let's call it CHECKMATE) big enough so that they are always great...
by tvrzsky
Tue Mar 16, 2010 10:57 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Hash Collision?
Replies: 82
Views: 8619

Re: Hash Collision?

Please, correct all "mat" to "mate". My poor english ... Hi Fred, do not give up! I believe that your bug (as has been pointed out by HGM) lies in handling mat scores in your hash table (TT). You have to realize that mat score is something very different from ordinary (material + position evaluation...
by tvrzsky
Tue Mar 16, 2010 1:49 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Hash Collision?
Replies: 82
Views: 8619

Re: Hash Collision?

Thanks Filip, I don't think I can absorb your post tonight, but tomorrow when I am fresher I will look at it closely. Good idea indeed, I slept only about 3 hours the last night myself and now it is here almost half past two AM ... I will respond to JW point though. If I am just doing transposition...