Senpai 1.0 (new engine)

Xann · Post by **Xann** » Mon Mar 17, 2014 7:41 pm

Hi Mark!

I don't smoke, but I do computer chess.
I tried to quit but ... it's not easy.
Say NO to computer chess

mvk · Post by **mvk** » Mon Mar 17, 2014 7:45 pm

Xann wrote: I have been working on a new GPL engine: Senpai.

Very nice and great to see you back!

Can you enlighten us about the cause of the 50% TT bug if you have found it? I think I have seen it before, long long time ago, but not even sure if it was in my own program or elsewhere...

Joerg Oster · Post by **Joerg Oster** » Mon Mar 17, 2014 7:45 pm

Nice to see you're back!

Senpai runs just fine under LinuxMint on my AMD FX-8120.
Another great participant for the next TCEC!
Thanks!

Gerd Isenberg · Post by **Gerd Isenberg** » Mon Mar 17, 2014 7:58 pm

Hi Fabien,

Wow, great news!
And congrats also for the 10th Fruit 1.0 anniversary.

I see, Senpai has little endian file:rank mapping. Allows cheaper pawn moves. Little bit disappointed about so many loops so far

For sliders, you traverse not only the first blocker but all pieces on those rays?

Code: Select all

bit_t piece_attacks_from(int pc, int f, const board::Board & bd) {

   assert(pc != piece::PAWN);

   bit_t ts = Piece_Attacks[pc][f];

   for (bit_t b = bd.all() & Blockers[pc][f]; b != 0; b = bit::rest(b)) {
      int sq = bit::first(b);
      ts &= ~Behind[f][sq];
   }

   return ts;
}

I guess you will gain some speedup later

Cheers & much fun,
Gerd

Xann · Post by **Xann** » Mon Mar 17, 2014 7:59 pm

I wish I knew the cause. I tried everything from random numbers, different ways of measuring the percentage, switching to unsigned numbers. None of this made any difference. So I guess one of the remaining candidates would be the scoring formula to decide which entry to overwrite.

Xann · Post by **Xann** » Mon Mar 17, 2014 8:05 pm

TCEC uses Linux?
But ... Senpai must first pass some stability test I suppose; we couldn't test SMP very much.

Xann · Post by **Xann** » Mon Mar 17, 2014 8:08 pm

Hi Gerd!

BTW I used CPW a lot when beginning the engine. This is so much easier than reading hundreds (if not thousands) of old posts.

Yes, I loop over all blockers. I somehow find this simple and elegant with the endgame in mind. In the middle game, I agree it's a sure way to cripple NPS though. There's a reason why nobody uses this.

Gerd Isenberg · Post by **Gerd Isenberg** » Mon Mar 17, 2014 8:13 pm

Xann wrote: Yes, I loop over all blockers. I somehow find this simple and elegant with the endgame in mind. In the middle game, I agree it's a sure way to cripple NPS though. There's a reason why nobody uses this.

Ok, this deserves an own sliding piece attack site devoted to you

Xann · Post by **Xann** » Mon Mar 17, 2014 8:14 pm

Are you sure? This looks like the most basic way to do bitboards.

tralala · Post by **tralala** » Mon Mar 17, 2014 8:16 pm

JuLieN wrote:As Fabien is a bit busy right now, I'll take a shot and emulate what his answers will probably be.

Steve Maughan wrote:+ After an absence of a few years, what was the motivation for writing Senpai?
The clones wars were fading, so I needed to release some new strong open sources. Plus we need a new R[edited out by moderator]a 5.

Steve Maughan wrote:+ How long did it take you write Senpai?
A pair of hours in a six years span.

Steve Maughan wrote:+ Why did you start a new codebase? Why not continue with the development of Fruit?
Fruit is lame, it's only about 2800.

Steve Maughan wrote:+ Have you accomplished everything you set out to do with Senpai, or is this a work-in-progress?
The answer is contained in the name of the engine.

Steve Maughan wrote:+ LMR became popular after it was introduced in Fruit - is there any new "secret sauce" in Sanpai which you think may be of interest to other programmers?
There's a big hint hidden in the release readme !

Steve Maughan wrote:+ Why did you choose C++11 as the development language?
Trendy is funny.

*hiding*

Too bad there is no liking functionality.

Senpai 1.0 (new engine)

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