BOX_C0_LOG        905 ext/gd/libgd/gd_topal.c #define BOX_C0_ELEMS  (1<<BOX_C0_LOG)	/* # of hist cells in update box */
BOX_C0_LOG        909 ext/gd/libgd/gd_topal.c #define BOX_C0_SHIFT  (C0_SHIFT + BOX_C0_LOG)
BOX_C0_LOG       1229 ext/gd/libgd/gd_topal.c   c0 >>= BOX_C0_LOG;
BOX_C0_LOG       1258 ext/gd/libgd/gd_topal.c   c0 <<= BOX_C0_LOG;		/* convert ID back to base cell indexes */