Which perft result is correct (and why)?

sluijten · Post by **sluijten** » Sat May 21, 2011 7:27 am

Finally have set up my Visual C+ Express to target for x64,
Perft gets a boost of 1.68x, comparing 32-bit mode with 64-bit mode, cool.

sluijten · Post by **sluijten** » Sat May 21, 2011 7:31 am

bob wrote:perft 7 from starting position: total moves=119060324 time=5.44

total moves=119060324 , isn't that perft 6?

bob · Post by **bob** » Sat May 21, 2011 7:34 am

sluijten wrote:
bob wrote:perft 7 from starting position: total moves=119060324 time=5.44
total moves=119060324 , isn't that perft 6?

Yes, "7" was next to "6" and in the dark...

sluijten · Post by **sluijten** » Sat May 21, 2011 2:19 pm

Just out of curiosity, on what CPU do you get this speed?

bob · Post by **bob** » Sat May 21, 2011 6:37 pm

sluijten wrote:Just out of curiosity, on what CPU do you get this speed?

This is an intel core-2 duo laptop, 2.53ghz, P9600. Nothing particularly "magic" as there are many much faster processors around...

Machine is a Dell Lattitude E4300

sluijten · Post by **sluijten** » Sun May 22, 2011 1:02 am

Hmmmm, you have programmed perft as a single thread (me too). My engine's perft 6 takes 11.7 seconds, running on an i3 M330 (2.13 GHz), which is only slightly slower than yours (not a factor 2).
- bitboards
- magics for ranks, files, and diagonals (so I need 4 multiplications for a queen)
I'll have to dig into this...

sluijten · Post by **sluijten** » Tue May 31, 2011 3:46 pm

Just added another perft test position here, #see 4. Not invented by me, but just thought it's a good one to keep for the records. Any volunteers to check my results? Or add the checkmate counts? (my perft doesn't count them).

sje · Post by **sje** » Thu Jun 02, 2011 3:35 am

[D]r3k2r/Pppp1ppp/1b3nbN/nP6/BBP1P3/q4N2/Pp1P2PP/R2Q1RK1 w kq - 0 1

Code: Select all

Depth&#58; 1   Count&#58; 6
Depth&#58; 2   Count&#58; 264
Depth&#58; 3   Count&#58; 9,467
Depth&#58; 4   Count&#58; 422,333
Depth&#58; 5   Count&#58; 15,833,292
Depth&#58; 6   Count&#58; 706,045,033
Depth&#58; 7   Count&#58; 27,209,691,363
Depth&#58; 8   Count&#58; 1,209,257,875,296

Mark · Post by **Mark** » Fri Jun 03, 2011 1:34 am

sje wrote:[D]r3k2r/Pppp1ppp/1b3nbN/nP6/BBP1P3/q4N2/Pp1P2PP/R2Q1RK1 w kq - 0 1

Code: Select all

Depth&#58; 1   Count&#58; 6
Depth&#58; 2   Count&#58; 264
Depth&#58; 3   Count&#58; 9,467
Depth&#58; 4   Count&#58; 422,333
Depth&#58; 5   Count&#58; 15,833,292
Depth&#58; 6   Count&#58; 706,045,033
Depth&#58; 7   Count&#58; 27,209,691,363
Depth&#58; 8   Count&#58; 1,209,257,875,296

I got the same results through depth 7. Took almost 4 hours!

elcabesa · Post by **elcabesa** » Fri Jun 03, 2011 7:08 pm

sluijten wrote:Hmmmm, you have programmed perft as a single thread (me too). My engine's perft 6 takes 11.7 seconds, running on an i3 M330 (2.13 GHz), which is only slightly slower than yours (not a factor 2).
- bitboards
- magics for ranks, files, and diagonals (so I need 4 multiplications for a queen)
I'll have to dig into this...

I'm playing with your code in Linux, I got your code compiling under Linux with few modification.

besides that i'm playing with your code to make it run faster. With my compiler (gcc) i got a big boost modifying move.c and move.h, setting all the move.h function (e.g. setFrom etc..) to inline gave me a +50%boost.

the original code took on my pc 29 seconds to compute perft 6, while the modified one took only 20 seconds. (maybe your compiler already set them inline automatically and you'll got no boost at all)

A big problem for your code to be fast is the fact you use a lot of "if" and "switch", I still don't know how to solve the problem, ( i'll dig inside it next days) ,but for example Stockfish has not a bitmap for every piece ( whiteking, white rook, etc,) instead it has a bitmap array indexed by piece type, this should remove a lot of if in you code!

I'm very interested in you code, and i'm learning a lot from it, good luck[/code]

Which perft result is correct (and why)?

Re: Which perft result is correct (and why)?

Re: Which perft result is correct (and why)?

Re: Which perft result is correct (and why)?

Re: Which perft result is correct (and why)?

Re: Which perft result is correct (and why)?

Re: Which perft result is correct (and why)?

Re: Which perft result is correct (and why)?

#4

Re: #4

Re: Which perft result is correct (and why)?