Search found 825 matches

by wgarvin
Tue May 31, 2016 10:01 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Undefined behavior
Replies: 10
Views: 1621

Re: Undefined behavior

A bit confusing that it doesn't simply say the array bounds are violated, when it apparently sees that they are. Unfortunately, by the time the compiler sees something bad that it wants to warn about, it has probably transformed the code into something quite different from what you started with, an...
by wgarvin
Thu May 26, 2016 12:58 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: public domain mini-LZ library
Replies: 14
Views: 1833

Re: public domain mini-LZ library

By the way, if you haven't come across them before, Charles Bloom has written years worth of good blog posts about LZ parsing. I suggest to start with these two: http://cbloomrants.blogspot.ca/2012/09/09-24-12-lz-string-matcher-decision-tree.html http://cbloomrants.blogspot.ca/2015/03/03-04-15-lz-ma...
by wgarvin
Fri May 20, 2016 11:49 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Interesting machine
Replies: 30
Views: 7020

Re: Interesting machine

5 pieces take about an hour on my machine (i7-3930K at 4.2Ghz, 6 cores / 12 threads). 6 pieces around 100x as long. Just an aside.. its awesome that we now live in a world where someone can generate 6-piece tablebases for chess in less than a week on a single machine costing only a few thousand dol...
by wgarvin
Fri May 20, 2016 2:13 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: How to speed up my engine
Replies: 88
Views: 12165

Re: How to speed up my engine

Asserts are a way for programmers to check their assumptions at runtime. If you thought the program would be in a certain state at that point and its not in that state, you want to find out about that sooner rather than later. As John Carmack once wrote: Most bugs are a result of the execution state...
by wgarvin
Thu May 19, 2016 7:47 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Question to syzygy author
Replies: 132
Views: 20593

Re: Question to syzygy author

Yours is linear in N and mine seems to be quadratic on average. Skipping the last loop is of course also possible in your approach. It is possble to do the unmapping in O(k) since you know the inner while loop (in Rein's modified code) will exit when sq is of the order of fact(k)*root^k(index). So ...
by wgarvin
Wed Apr 06, 2016 1:49 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Some questions from a beginner
Replies: 27
Views: 5977

Re: Some questions from a beginner

Thanks for your detailed explanations, Gerd! And also to you Sven! This really helps me a lot! I'm looking forward to reimplementing the slider attacks with the magics I just fed my move generation with the 218-move-position and the engine found them all :) And yes, you can compute the magics on th...
by wgarvin
Sat Mar 12, 2016 7:50 pm
Forum: Computer Chess Club: General Topics
Topic: Go has fallen to computer domination?
Replies: 161
Views: 36068

Re: Go has fallen to computer domination?

These poor programmers or researchers that switched from Chess to GO after it appeared that Chess had been 'solved' where should they go to now ? Apparently StarCraft. I would be surprised if that's even as hard, but I know nothing about it. StarCraft is an RTS with 3 assymetric but extremely well-...
by wgarvin
Sat Mar 12, 2016 9:53 am
Forum: Computer Chess Club: General Topics
Topic: Lee Sedol vs. AlphaGo [link to live feed]
Replies: 121
Views: 27647

Re: Lee Sedol vs. AlphaGo [link to live feed]

I awoke early, so I watched most of game 3. I found Michael Redmond's commentary annoying today. I may be overestimating, but today it seemed as though about 3/4 of the time he was guessing the next player's move wrongly, and then doing variations from a position that the viewer could see was never...
by wgarvin
Wed Jan 13, 2016 10:55 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: smaller tables for PEXT-style attack getters
Replies: 4
Views: 1272

Re: smaller tables for PEXT-style attack getters

For rooks I guess you'd need 64*(4*sizeof(BB) + 2*sizeof(PTR)), plus the 8 occupancy lookup tables which are 64 bytes each. So that adds up to a measly 3.5 KB on a 64bit machine. Bishops might need more occupancy tables, I am not sure. Even with a pessimistic assumption of needing 64 occupancy table...
by wgarvin
Wed Jan 13, 2016 10:36 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: smaller tables for PEXT-style attack getters
Replies: 4
Views: 1272

smaller tables for PEXT-style attack getters

A half-baked idea just came to me, but maybe Gerd or someone, will pick it up and run with it. :D I was thinking about PEXT/PDEP for rook or bishop attacks, and it occurred to me that you could use two different masks for the same square (i.e. instead of a table lookup of up to 12 bits, you'd have t...