Best Board Representation for 32bit CPUs

[net]

What is the best board representation for 32bit CPU?

I'm planning to run my chess engine (when it's developed, will be starting development at the end of the summer) on a raspberry pi or a beagleboard and unfortunately those are 32 bit processors. It's too bad that they don't have 64bit yet so I'll have to forgo using bitboards.

Thanks.

p.s. I found this research paper http://www.doiserbia.nb.rs/img/doi/0354 ... 00011V.pdf unfortunately they didn't run move generation benchmarks o_O

[H.G.Muller]

Probably a ray representation, where you describe the board as a collection of rays, and have a bit set for each ray. An 4x64 table would tell you for each square and direction at what index you can find the ray running through that square in a given direction.

[Gerd Isenberg]

HGM's Ray Vectors seem quite nice specially for greater board sizes. You may have a look to 15*N or 16*N Vector Attacks, ala Reul's none bitboard New Architecture with compact blocking loops to generate captures. With 16 32-bit registers of the ARM processor one may still consider bitboards. There is a 32-bit optimized bitscan by Matt Taylor, and resource friendly 32-bit kindergarten bbs to generate sliding attacks. I am a bit skeptical concerning the performance of Vučković's Compact Chessboard Representation, thanks for posting his paper, which seems a revised version of the his (2008) ICGA Journal paper.

[H.G.Muller]

Indeed, the idea was that when you only have a 32-bit machine, 8x8 is already a 'larger board size'.

[net]

thanks