SQUARE_FROM_64    188 src/board.cpp        sq = SQUARE_FROM_64(sq_64);
SQUARE_FROM_64    242 src/board.cpp           sq = SQUARE_FROM_64(sq_64);
SQUARE_FROM_64    317 src/board.cpp           sq = SQUARE_FROM_64(sq_64);
SQUARE_FROM_64     37 src/move.h     #define MOVE_FROM(move)                (SQUARE_FROM_64(((move)>>6)&077))
SQUARE_FROM_64     38 src/move.h     #define MOVE_TO(move)                  (SQUARE_FROM_64((move)&077))