Search found 4166 matches

by syzygy
Tue Jul 10, 2012 11:40 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Proper way to learn c ?
Replies: 63
Views: 11961

Re: Proper way to learn c ?

mar wrote:
syzygy wrote:I don't see why a kernel written in C++ could not run existing C programs.
Name mangling being reason #1 (overloading). There's more, much more :wink:
Do you realise that Linux executables are not linked against kernel object code?

Name mangling is not an issue here at all.
by syzygy
Tue Jul 10, 2012 8:04 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Proper way to learn c ?
Replies: 63
Views: 11961

Re: Proper way to learn c ?

Huh. C++ is a superset of C. So I really don't see why Torvalds wanted to rewrite the kernel in C++, that's completely stupid as it would break existing C programs. :shock: I see two reasons why that "C++ rewrite" of the Linux kernel failed: 1) You cannot simply "rewrite" something as complex as an...
by syzygy
Tue Jul 10, 2012 7:54 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Random value compute or table hard coded ?
Replies: 25
Views: 3624

Re: Random value compute or table hard coded ?

Do you know why strelka crash with this method, Well, your code clearly has a bug. It is not the method that crashes the program, but something you did when implementing the method. Maybe you didn't properly allocate the memory where you store the random values. Maybe you don't properly reference t...
by syzygy
Wed Jul 04, 2012 10:32 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: LMR Research
Replies: 21
Views: 5688

Re: LMR Research

bob wrote:You should not draw conclusions on a few test positions, rather over complete games, where the difference is not so big.
bob wrote:I didn't say "test positions". I said "positions".
by syzygy
Sat Jun 30, 2012 2:40 pm
Forum: Computer Chess Club: General Topics
Topic: Question about Critter 1.6 & Gaviota gtb's
Replies: 14
Views: 2931

Re: Question about Critter 1.6 & Gaviota gtb's

I would be surprised if HDD seek time beats USB2 access time. For tablebase access, seek time is what counts. USB access is 20-100x faster than HDD-access. Because of that, all TBs are very, very slow on HDDs! Yes, that's what I thought. Of course a real SSD would perform better than a USB stick. N...
by syzygy
Fri Jun 29, 2012 11:47 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: info about zappa on 512 cores ?
Replies: 23
Views: 3904

Re: transposition tables

Give N small hash tables of the same size with K entries, how do you hash a position with zobrist hash hash_key ? Assume the small hash tables are physically separate (on different processor if you will). If I understand you correctly, the N small hash tables form one large hash table. Each positio...
by syzygy
Fri Jun 29, 2012 8:49 pm
Forum: Computer Chess Club: General Topics
Topic: Question about Critter 1.6 & Gaviota gtb's
Replies: 14
Views: 2931

Re: Question about Critter 1.6 & Gaviota gtb's

flash memory certainly lessens wear and tear on the HDD. But what about access time? Using flash memory requires USB (usb2 in most cases) access time as opposed to HDD access time. I would be surprised if HDD seek time beats USB2 access time. For tablebase access, seek time is what counts. Of cours...
by syzygy
Mon Jun 25, 2012 7:02 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Texel recipe to fix TT draws scores
Replies: 8
Views: 1660

Re: Texel recipe to fix TT draws scores

If fixes the problem during the last 20 plies before the 50-move rule that hash grafts can cause the 50-move rule to be applied incorrectly. It doesn't in general fix draw by repetition problems though. It may "accidentally" fix some draw by repetition problems as a side effect of giving fewer hash...
by syzygy
Sun Jun 24, 2012 2:24 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: KQKP and KRKP endgames
Replies: 38
Views: 3544

Re: KQKP and KRKP endgames

In the eval, you only need suitable PSTs for solving KQK, KBNK, KRK, and you need nothing special to play KQKQ perfectly. So this can't be what Joona is talking about. I almost agree, except for the "PST" argument since mating the lone king usually also requires to approach the own king to the enem...
by syzygy
Sun Jun 24, 2012 12:39 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: KQKP and KRKP endgames
Replies: 38
Views: 3544

Re: KQKP and KRKP endgames

Could it be that Joona is talking about internal node recognisers that cut a whole subtree when a position with known outcome is reached? I suppose it could indeed be hard to statically determine with 100% certainty whether KQKQ is draw, but I don't see the need for the evaluation to evaluate KQKQ ...