Search found 825 matches

by wgarvin
Thu Nov 13, 2014 2:05 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: learning question about programs
Replies: 10
Views: 2134

Re: learning question about programs

There was some research around 1998 on this (learning evaluation weights) using the program KnightCap and a "TD-Lambda" algorithm.

https://www.google.ca/#q=knightcap+td+lambda

I don't know if that approach would be successful with today's engines.
by wgarvin
Mon Nov 10, 2014 12:20 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Super Fast 'Looking for magics' 1.0
Replies: 18
Views: 4606

Re: Super Fast 'Looking for magics' 1.0

It looks basically the same as this folding trick by Matt Taylor , although the multiplication constant and BitTable sequence are not quite the same as what is listed on that page. Also, in Stockfish you can find this snippet which I suppose is derived from Tord's original code: // De Bruijn sequenc...
by wgarvin
Sun Nov 09, 2014 2:30 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Super Fast 'Looking for magics' 1.0
Replies: 18
Views: 4606

Re: Super Fast 'Looking for magics' 1.0

I assume this is the table being asked about? const int BitTable[64] = { 63, 30, 3, 32, 25, 41, 22, 33, 15, 50, 42, 13, 11, 53, 19, 34, 61, 29, 2, 51, 21, 43, 45, 10, 18, 47, 1, 54, 9, 57, 0, 35, 62, 31, 40, 4, 49, 5, 52, 26, 60, 6, 23, 44, 46, 27, 56, 16, 7, 39, 48, 24, 59, 14, 12, 55, 38, 28,...
by wgarvin
Mon Nov 03, 2014 12:10 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Perft(14) Weekly Status Report
Replies: 73
Views: 13072

Re: Perft(14) Weekly Status 2014-11-02

There is some slightly scary news with using OpenCL, needed by Oscar in OpenCL mode, on some Apple hardware. It seems that some Macs have heat related failure with the lead-free solder used to connect certain discrete graphic processor chips. The solder joints fail after the GPU runs long and hot, ...
by wgarvin
Sun Nov 02, 2014 11:56 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: UCCI2WB
Replies: 129
Views: 10946

Re: UCCI2WB

If there is only one legal move, the GUI could just make it and not bother the engine. In fact, it wouldn't even have to start the clock. Once the GUI makes a game decision, it is no longer a GUI. That "I" in GUI has a very distinct meaning, it is supposed to simply serve as an interface between th...
by wgarvin
Wed Oct 22, 2014 1:22 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Intel compiler bug?
Replies: 30
Views: 4634

Re: Intel compiler bug?

Oh, I just thought of another good compiler bug. Two of the compilers we currently use (from the same vendor) have a ridiculous parsing bug in them where sometimes they "forget" about an enum declaration and incorrectly report compile errors everywhere you try to use it. One of the compilers is near...
by wgarvin
Wed Oct 22, 2014 1:07 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Intel compiler bug?
Replies: 30
Views: 4634

Re: Intel compiler bug?

I agree, but this is now a confirmed high priority defect that exists since late XE 11 and will be fixed in some of the upcoming updates. If you pay $700 for a compiler (I did), you don't expect it to break some trivial multiply with 256; OTOH bugs just happen. At least they could have given me a d...
by wgarvin
Thu Oct 16, 2014 9:58 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Intel compiler bug?
Replies: 30
Views: 4634

Re: Intel compiler bug?

Quite expensive.... $699 for a single developer "base" license... Yes, considering it's buggy :) Pretty much all optimizing compilers are a little bit buggy, even extremely-well-tested ones. A modern optimizing compiler has a LOT of complex parts that can interact with each other in really subtle w...
by wgarvin
Thu Oct 16, 2014 9:44 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Tablebase access using a Solid State Disk
Replies: 2
Views: 1095

Re: Tablebase access using a Solid State Disk

What's really nice about SSDs is that their "seek time" is pretty much zero. For some use cases that makes a really huge difference. If you get a quality one, the raw throughput will also be excellent.
by wgarvin
Thu Apr 24, 2014 11:57 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Simplified Chess
Replies: 20
Views: 3709

Re: Simplified Chess

The first-repeat-is-a-draw rule seems too draconian, to me. Suppose I advance my queen, and you move something (a knight) to threaten it. I realize my mistake, but I am not allowed to retreat back to my original position without effectively offering you a draw :)