Search found 1605 matches

by Gerd Isenberg
Tue Jun 05, 2018 9:02 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Bitboard for a non-chess game
Replies: 4
Views: 607

Re: Bitboard for a non-chess game

The naive disjunctiv normal form approach would be, with some subexpressions to optimize oneEmptyNeighbor = ( occupied_shift_left & ~occupied_shift_down & ~occupied_shift_right & ~occupied_shift_up) | (~occupied_shift_left & occupied_shift_down & ~occupied_shift_right & ~occupied_shift_up) | (~occup...
by Gerd Isenberg
Fri Apr 20, 2018 11:30 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Chess Programming Wiki
Replies: 30
Views: 11433

Re: Chess Programming Wiki

CPW is under Creative Commons Attribution-ShareAlike 3.0 Unported (CC BY-SA 3.0).

The new wikimedia cpw makes good progress and will be available in about July with revisited and new content and links. No need to waste bandwidth or memory.
by Gerd Isenberg
Mon Mar 19, 2018 9:30 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Chess Programming Wiki
Replies: 30
Views: 11433

Re: Chess Programming Wiki

We have wikitext backups, and some months time to look for another host. How about digitalocean.com? They're $5/mo. and you get 25gb of ssd disk space, a full linux shell enviornment where you can install whatever you want. I would like to see the 'wikitext backup' for this page: https://chessprogr...
by Gerd Isenberg
Wed Feb 21, 2018 8:32 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Some opening book design questions
Replies: 39
Views: 7750

Re: Some opening book design questions

I wondered about this ymmetry business. In Chess you could also do BW mirroring. But no one I know does this, because in good Chess openings the mirrored positions just never occur. To reach them white would have to lose a tempo, and this is considered very bad in Chess. Is it really an advantage t...
by Gerd Isenberg
Wed Feb 21, 2018 9:52 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Chess Programming Wiki
Replies: 30
Views: 11433

Re: Chess Programming Wiki

1. The US Patent for Gothic Chess was sold for $250,000 to the International team who took a 50% share in the international profits once the International Patent was awarded. Why all the citation claiming "unpaid maintenance fees?" Not even close to the reason. The International Patent overshadows ...
by Gerd Isenberg
Mon Feb 12, 2018 3:32 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Chess Programming Wiki
Replies: 30
Views: 11433

Re: Chess Programming Wiki

I have noticed the announcement that Wikispaces, which is hosting the Chess Programming Wiki, is shutting down ( http://blog.wikispaces.com/ ). I hope there are plans to migrate the content elsewhere, because it has been a good resource and reference. --Jon We have wikitext backups, and some months...
by Gerd Isenberg
Sat Feb 10, 2018 8:22 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: magic number comprising offset
Replies: 5
Views: 1651

Re: magic number comprising offset

Nice! One extra register, parallel executed "and" (with mul) instead of L1 access. I guess it depends on the surrounding instructions and register pressure whether your proposal is faster or slower.
by Gerd Isenberg
Sun Jan 28, 2018 6:51 pm
Forum: Computer Chess Club: General Topics
Topic: BishBosh, Butter-Chess and Chess Engine
Replies: 7
Views: 1032

Re: BishBosh, Butter-Chess and Chess Engine

Günther, can you tell me the exact url of Butter-Chess , please? The current github package is from 09-11-2017. Norbert Readme from Sep 12, 2017 doesn't fit to to the remaining sources from Feb 11, 2017. Readme claims Magic bitboards, Principal variation search, and Null move pruning - which are no...
by Gerd Isenberg
Tue Jan 16, 2018 10:12 am
Forum: Computer Chess Club: General Topics
Topic: Zevra 1.6.2 r536
Replies: 40
Views: 6407

Re: Tevra 1.6.2 r536

Hi Oleg, your code looks like from an obfuscation contest or compiler optimization test - a violation of using bitboards ;-) One sample of many: uint64_t possibleMoves, mask, emask; uint8_t color; if(currentState.whiteMove) { color = WHITE; mask = currentState.white_bit_mask; emask = cu...
by Gerd Isenberg
Fri Dec 15, 2017 5:13 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: N Queens Puzzle Algorithm
Replies: 10
Views: 1949

Re: N Queens Puzzle Algorithm

Mine, Marcel van Kervinck's and Tony Lezard's 8Q approaches:

https://chessprogramming.wikispaces.com ... 0Bitboards