Search found 692 matches

by rbarreira
Sat Aug 30, 2014 9:04 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: How many Elo points change for a doubling of uP time?
Replies: 13
Views: 2811

Re: How many Elo points change for a doubling of uP time?

I expect that it's dependent on how long the time control is. If two engines are playing very long games with good hardware, the number of draws will go up and therefore the advantage of playing better chess is smaller. In very fast games, the quality of the engine shows more as there are fewer draws.
by rbarreira
Sat Jul 26, 2014 5:54 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Linus on gcc-4.9: "your compiler is pure and utter *shi
Replies: 9
Views: 2589

Re: Linus on gcc-4.9: "your compiler is pure and utter

Actually after reading this: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61904 And the similar bug linked there, I think the problem is also present in gcc 4.5.0 through 4.8.3, as well as 4.9.0 and 4.9.1. And it seems to be possible even without -mno-red-zone. On the good side, it seems to be cause...
by rbarreira
Sat Jul 26, 2014 5:00 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Linus on gcc-4.9: "your compiler is pure and utter *shi
Replies: 9
Views: 2589

Re: Linus on gcc-4.9: "your compiler is pure and utter

I don't think anyone compiles their chess engines with -mno-red-zone, so I don't think you should worry too much about this, unless this bug also happens in other ways not illustrated in that email.

As for the constant spilling, that's just a performance problem, not a functional bug.
by rbarreira
Mon Mar 24, 2014 1:00 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: volatile?
Replies: 186
Views: 26369

Re: volatile?

What version of gcc did you use? If you truly have seen gcc optimizing out checks on a variable that's accessed after a call to the standard pthread_mutex_lock then you have found a library and/or compiler bug. He's not calling the standard pthread_mutex_lock. He copied and pasted from the pthreads...
by rbarreira
Sun Mar 23, 2014 10:15 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: volatile?
Replies: 186
Views: 26369

Re: volatile?

OK, some specific points. 1. If you choose to lock EVERY shared access, you still have a problem For example, the simple spin lock in Crafty where a thread waits on work. Do you want to lock to READ the value? As well as write the value? How does that solve the problem? You acquire the lock, you re...
by rbarreira
Sat Mar 22, 2014 9:28 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Solving Chess Kickstarter
Replies: 109
Views: 26864

Re: Solving Chess Kickstarter

This paragraph of the Kickstarter is hilarious: I have currently written software to represent a chess position and a chess move. It can make and unmake moves. It can generate possible moves, check if squares are attacked, etc. What I'd like to do as a first step is finalize this code with extensive...
by rbarreira
Fri Mar 21, 2014 9:19 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: volatile?
Replies: 186
Views: 26369

Re: volatile?

The code looks ugly to me and is probably not safe. If you had just read : It seems splitPoint->moveCount is always accessed under lock protection (except for an assert), so it seems it could be made non-volatile. Please spare us your confused "contributions" if you can't take the time to read firs...
by rbarreira
Fri Mar 21, 2014 12:40 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: volatile?
Replies: 186
Views: 26369

Re: volatile?

The code looks ugly to me and is probably not safe. If you had just read : It seems splitPoint->moveCount is always accessed under lock protection (except for an assert), so it seems it could be made non-volatile. Please spare us your confused "contributions" if you can't take the time to read firs...
by rbarreira
Fri Mar 14, 2014 6:45 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Null move and LMR
Replies: 8
Views: 2689

Re: Null move and LMR

Thanks guys, Im getting the idea now. I don't want to add anything to my program until I understand it. I think I could implement it, but could anyone help with some sample documented code (Imagine you are explaining to a 5 year old) Im guessing its something like: if MoveNumber > something then Re...
by rbarreira
Mon Mar 10, 2014 1:52 am
Forum: Computer Chess Club: General Topics
Topic: Please stop developing free Stockfish
Replies: 34
Views: 9753

Re: Please stop developing free Stockfish

Could you describe the "Free Stockfish Problem" please?