Search found 724 matches

by jwes
Mon Jul 17, 2017 3:04 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: PEXT Bitboards
Replies: 19
Views: 7146

Re: PEXT Bitboards

lucasart wrote:To make software PEXT useful for chess, it needs to be on par with magic multiplication. And I really don't think the above will be.

So, the choice is still between hardware PEXT and Magic.
Of course, the main reason for such a routine would be to make your program compatible with older processors.
by jwes
Sun Jul 16, 2017 4:40 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Hash table bug
Replies: 24
Views: 3021

Re: Hash table bug

The first thing I would look at is why your program thinks Qc1 is not a good reply. Either use a debugger or put in enough log statements to see why. Three other things: 1. the PV from ply 4 does not show a score at ply 5. 2. The first line at ply 5 (5 70 261 3778419 h4h6 g7h6 f2f3 e4f3) has a very...
by jwes
Sat Jul 15, 2017 11:08 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Hash table bug
Replies: 24
Views: 3021

Re: Hash table bug

The first thing I would look at is why your program thinks Qc1 is not a good reply. Either use a debugger or put in enough log statements to see why. Three other things: 1. the PV from ply 4 does not show a score at ply 5. 2. The first line at ply 5 (5 70 261 3778419 h4h6 g7h6 f2f3 e4f3) has a very ...
by jwes
Sun Jul 09, 2017 6:07 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: On-line engine blitz tourney June
Replies: 41
Views: 6218

Re: On-line engine blitz tourney June

Why are you guys calling these things in assembly? I use built-in functions like __builtin_ctzll and I don't have to worry about such low-level details as what bits in rax are set by some instruction. I thought everyone would be using built-in functions these days. The problem with built-in functio...
by jwes
Sun Jul 02, 2017 11:32 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Algorithm for mate recognition
Replies: 10
Views: 2279

Re: Algorithm for mate recognition

I think after this, you would need to look at ASCII conversion and overlapped I/O to speed it up significantly. ASCII conversion takes 12,69% of the time and fwrite 8,47%. Thanks for your suggestions, I will test them. However the atks array will be very huge: 20 bytes * 64 * 64 = 80kB I suspect th...
by jwes
Sun Jul 02, 2017 6:07 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Algorithm for mate recognition
Replies: 10
Views: 2279

Re: Algorithm for mate recognition

I think after this, you would need to look at ASCII conversion and overlapped I/O to speed it up significantly.
by jwes
Sun Jul 02, 2017 5:07 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Algorithm for mate recognition
Replies: 10
Views: 2279

Re: Algorithm for mate recognition

Thanks for the reply, I should have stated clearly my objective. I profiled SCID code when exporting a database to PGN and discovered that a lot of time is spent testing for check/mate. The current code works mostly like you suggested: it is only missing the cutoff. Exporting 1 million games to PGN...
by jwes
Thu Jun 22, 2017 1:09 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Testing endgame strength
Replies: 11
Views: 2390

Re: Testing endgame strength

Hi, I want to start working on the late-endgame evaluation in RuyDos. I have a lot of ideas of what to try, but no good way to test them. The standard mechanism of playing a gazillion bullet games has the problem that most bullet games (at least at my engine's current skill level) don't make it to ...
by jwes
Tue Jun 13, 2017 4:03 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: End game and Null move
Replies: 8
Views: 1675

Re: End game and Null move

In general we don't do null move in the end game because of the danger of ZugZwang. BUT: How common is zugzwag ? How endgame is endgame ? Is it worth drawing a few games due to zugzwang to get the extra depth search gives with null move ? Would my elo be better if I didn't worry about protecting ag...
by jwes
Tue Jun 13, 2017 1:22 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Zobrist free
Replies: 32
Views: 4758

Re: Zobrist free

I run it almost 24/7 on the chess servers. I also run routinely thousands of games on 60 distributed cores for several hours at a stretch, for testing. Sometimes I have had practically 24/7 usage on that cluster for days. Stockfish also does not do full legal move checking - it calls pos.pseudo_leg...