Search found 724 matches

by jwes
Sat Jun 10, 2017 9:41 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Fastest pawn quiet move generation I was able to come with
Replies: 25
Views: 4272

Re: Fastest pawn quiet move generation I was able to come wi

Sure someone can improve this, but I think is really fast. b = bitboard of pawns increment = 8 or 16 uint8_t cas; uint8_t casd; switch (popcount(b)) { default: //> 8 pawns for strange games or positions altremovpeo2 : if (b == 0) return ml; cas = lsb(b); casd = cas ...
by jwes
Mon May 29, 2017 7:02 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: insufficient mating material
Replies: 9
Views: 2062

Re: insufficient mating material

So, the way I was handling this rule was to declare it a draw if both sides had insufficient mating material. However, the presence of enemy pieces that can box in their own king makes this an invalid assumption. Perhaps this is better suited to a lookup. A lookup doesn't help much either. You can ...
by jwes
Sun May 14, 2017 12:55 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: BMI2 intrinsics in gcc
Replies: 3
Views: 1289

Re: BMI2 intrinsics in gcc

Hi, I am trying to use the BMI2 instructions with gcc built-ins. According to the documentation I can find, there should be a function _pdep_u64 if I am compiling with -mbmi2, but whatever I try, the compiler complains that it doesn't know that function. I have gcc version 5.3.0. Any ideas? Thanks!...
by jwes
Sun May 07, 2017 8:26 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Open and parse Winboard.debug file while in use by Winboard
Replies: 4
Views: 1148

Re: Open and parse Winboard.debug file while in use by Winbo

Thanks. Seems I might have a solution now and that the problem was actually my program putting on some sort of a lock when attempting to open to read, which Windows denies. So Google suggests opening files as a stream with no locks to get around this problem and in FreePascal that can be done with ...
by jwes
Sat May 06, 2017 2:59 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Search-Based Opening Book Construction
Replies: 10
Views: 2442

Re: Search-Based Opening Book Construction

I have been thinking about taking my existing book, evaluating all the terminal positions and using minimax values in move selection. Then possibly using dropout expansion. Currently it correctly avoids a lot of bad lines and selects good ones, but the move weights are probably not very optimal. I ...
by jwes
Mon Apr 24, 2017 12:37 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Sorting algorithms
Replies: 61
Views: 13494

Re: Sorting algorithms

I asked something similar a few weeks ago. My sorting is a bit more advanced than what I understood your engine does: 1) I split into phases: hash, captures / queen promotion, killers, quiets. 2) I sort each phase separately, but only if needed. E.g. I don't sort quiets if I'm not done with killers...
by jwes
Wed Apr 19, 2017 2:43 am
Forum: Computer Chess Club: General Topics
Topic: Position easy for computers, hard for me
Replies: 2
Views: 606

Position easy for computers, hard for me

I was going through games my program my program played and came across this position. [d]4k3/5pB1/p3bPr1/1p1qn1pp/5r1P/P1Pp2R1/1P1Q1NP1/R5K1 b - - 0 35 When I saw the move, I thought it was a blunder, but stockfish very quickly showed a winning advantage. Do others have as much difficulty seeing the...
by jwes
Fri Mar 31, 2017 4:23 am
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: WAC 100
Replies: 22
Views: 5311

Re: WAC 100

Texel using MPV:3 found that Be3 is no worse than Mate in 42. 25 06:30 4,445,666,578 11,393,389 +M42 Be3 Bb6 Bd2 Bc7 b6+ Bxb6 Kb5 Bd8 Be3 Ka8 Kxc5 Ba5 Kc6 Bc3 c5 Bb2 Kb5 Ba3 c6 Bd6 Kc4 Kb8 Kd5 Bc7 Ke6 Ka8 Kd7 Ba5 a7 Bb6 Bc1 Kxa7 c7 Bxc7 Kxc7 Ka8 Bd2 Ka7 Be3+ Ka6 Kc6 Ka5 Kd7 Kb4 Bd2+ Kc4 Ke6 Kd3 Kxf...
by jwes
Wed Mar 15, 2017 8:53 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: How to find SMP bugs ?
Replies: 15
Views: 3461

Re: How to find SMP bugs ?

I have a working SMP implementation (lazy). It even scales very well… When it doesn't crash. Problem is: crashes are never reproducible, they just happen randomly. How do you go about finding SMP bugs ? So far the only method I can think of is to remove things one by one, and continue so long as th...
by jwes
Sat Feb 18, 2017 5:56 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Checkers Is Strongly-Solved for 8-pieces
Replies: 98
Views: 30329

Re: Checkers Is Strongly-Solved for 8-pieces

So tell me, what compression technique did they use "20 years ago" that compressed data that used all 256 numbers from 0 to 255 within a single byte? Oh, that's right, there was none You know nothing about compression algorithms? You didn't answer my question. What did "they" use 20 years ago to co...