FIELD_DWORD_SHIFT
#define FIELD_BIT_MASK(type, field) (((1 << FIELD_BIT_SIZE(type, field)) - 1) << FIELD_DWORD_SHIFT(type, field))
#define SET_VAR_FIELD(var, type, field, val) var[FIELD_DWORD_OFFSET(type, field)] &= (~FIELD_BIT_MASK(type, field)); var[FIELD_DWORD_OFFSET(type, field)] |= (val) << FIELD_DWORD_SHIFT(type, field)