_iclass
#define ICLASS(ilp) ((ilp)->_iclass.class_u.class_chunk)
#define ICLASS_SET(ilp, l) ((ilp)->_iclass.class_u.class_chunk = (l))
((_Classification)(((ilp)->_iclass.class_u.class_ar[0] << 8) | \
(ilp)->_iclass.class_u.class_ar[1]))
((ilp)->_iclass.class_u.class_ar[0] = (uint8_t)((l)>> 8), \
(ilp)->_iclass.class_u.class_ar[1] = (uint8_t)(l))