Search found 4 matches

by Pemrograman
Thu May 09, 2013 12:45
Forum: Draughts, Computer, Internet
Topic: International checkers bitboard representation
Replies: 8
Views: 6010

Re: International checkers bitboard representation

[...] We never thought of bitwise rotate, only bitwise shift, and then 64 bits are not enough to wrap all 4 edges :( Main reason why bitwise rotate is not so much used is that C++ does not have a builtin operator for it. Do you perhaps program in Java? C++, I use the vs2012 compiler intrinsics for ...
by Pemrograman
Wed May 08, 2013 14:37
Forum: Draughts, Computer, Internet
Topic: International checkers bitboard representation
Replies: 8
Views: 6010

Re: International checkers bitboard representation

But if you offset the cylinder with a row of ghosts, wouldn't that lead to a donut with wrangled seams and achieving the same goal? It would require the rotate instruction though. [57][58][59][60][61][62] [63] 00, 01, 02, 03, 04, 05, 06, 07, 08, 09, [10] [10] 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, ...
by Pemrograman
Wed May 08, 2013 11:39
Forum: Draughts, Computer, Internet
Topic: International checkers bitboard representation
Replies: 8
Views: 6010

Re: International checkers bitboard representation

This design was inspired by that bitboard tutorial. In a spreadsheet I tried different values for left and right rotating, and found that 1 and 14 worked very nice. I had not read about the ghost square bitboard, and I probably would not have tried this approach if I had known about it. I'm not comp...
by Pemrograman
Wed May 08, 2013 01:02
Forum: Draughts, Computer, Internet
Topic: International checkers bitboard representation
Replies: 8
Views: 6010

International checkers bitboard representation

I don't know if this is already known, but I found that using this bit layout has some nice properties. 49 36 23 10 61 48 35 22 9 60 34 21 8 59 46 33 20 7 58 45 19 6 57 44 31 18 5 56 43 30 4 55 42 29 16 3 54 41 28 15 53 40 27 14 1 52 39 26 13 0 With 64 bit, it is always rotate 1 or rotate 14 bits. F...