Search found 269 matches

by Aaron Becker
Fri Sep 23, 2016 2:03 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Correct node counting ?
Replies: 6
Views: 1438

Re: Correct node counting ?

I don't think there's a clear standard for what counts as a node--different engines count differently.

One common, simple approach is "increment the node count whenever you make a move".
by Aaron Becker
Thu Sep 22, 2016 6:05 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Google Compute Engine pre-emptible instances
Replies: 11
Views: 2873

Re: Google Compute Engine pre-emptible instances

I don't think Oracle cares about selling to anyone who isn't spending millions of dollars. Computer chess hobbyists aren't really their target market :)
by Aaron Becker
Fri Sep 09, 2016 6:46 am
Forum: Computer Chess Club: Tournaments and Matches
Topic: CCRL Engine Authors' Tournament (will start October 1st)
Replies: 181
Views: 33033

Re: CCRL Engine Authors' Tournament (will start October 1st)

I've been quietly working on a rewrite of Daydreamer. If it's ready in time, I'd like to enter it.
by Aaron Becker
Fri Jan 17, 2014 3:34 am
Forum: Computer Chess Club: General Topics
Topic: Good question: What % improvement is hardware vs. software?
Replies: 9
Views: 2108

Re: Good question: What % improvement is hardware vs. softwa

I don't think it's really possible to disentangle the effects of improved hardware and improved software, because they have evolved together. For example, modern bitboard move generation is a giant leap forward from 70's techniques, but it couldn't have practically been used on the hardware of the 7...
by Aaron Becker
Tue Jan 07, 2014 9:18 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: How to compile discocheck?
Replies: 14
Views: 2087

Re: How to compile discocheck?

The error message suggests that the build is actually using an older compiler that doesn't understand c++11. You might need to edit make.sh to explicitly use g++-4.8 or something along those lines.
by Aaron Becker
Tue Jan 07, 2014 9:13 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: copy/make vs make/unmake
Replies: 8
Views: 2836

Re: copy/make vs make/unmake

Weird coincidence, I've been slowly revamping my engine and ran a similar do/undo vs copy experiment last week. My result was similar--about a 5% advantage to explicit undo (with a somewhat smaller board state to copy).
by Aaron Becker
Tue Dec 10, 2013 7:35 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: How could a compiler break the lockless hashing method?
Replies: 312
Views: 28010

Re: How could a compiler break the lockless hashing method?

I think you are confusing an unknown/undefined value with undefined behaviour. The latter is a technical term with a specific, well-defined, meaning. Reading a volatile variable isn't UB. Well, it was said somewhere that race conditions are mentioned in the standard as a form of undefined behavior,...
by Aaron Becker
Mon Dec 09, 2013 4:02 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: How could a compiler break the lockless hashing method?
Replies: 312
Views: 28010

Re: How could a compiler break the lockless hashing method?

On a side note, you can find a good overview of potential pitfalls in the use of volatile variables here: http://blog.regehr.org/archives/28. Items 5-8 are especially relevant. I think people often overestimate the guarantees that volatile variables provide, and the insides of modern superscalar mul...
by Aaron Becker
Mon Dec 09, 2013 3:46 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: How could a compiler break the lockless hashing method?
Replies: 312
Views: 28010

Re: How could a compiler break the lockless hashing method?

The C standard in fact agrees with you: Accessing a volatile object, modifying an object , modifying a file, or calling a function that does any of those operations are all side effects, which are changes in the state of the execution environment. Evaluation of an expression may produce side effect...
by Aaron Becker
Wed Mar 13, 2013 6:25 am
Forum: Computer Chess Club: General Topics
Topic: Selling Chess engines?!
Replies: 13
Views: 2926

Re: Selling Chess engines?!

Today I came across this interesting app in the Play Store: https://play.google.com/store/apps/details?id=org.chessenginespack It has bundled all UCI engines for Android with NO Chess board or UI and is being sold for $1.29!! "Free updates forever." <-- Classic! :-) Developer's site: http://juanlui...