RD
#define RD(machcode) (((machcode) >> 25) & 0x1f)
#define RD(x) (((union instruct *) (x))->f_3c.rd)
#define RD(r) (ac)->rd((ac)->private, (r))
RD(queue_t *q)
#undef RD
#define RD(x) (((x) >> 25) & 0x1f)