c.ctxt.Diag("illegal combination: %v", p)
		}

	case 20: /* mov/movb/movbu R,O(R) */
		c.aclass(&p.To)

		r := int(p.To.Reg)
		if r == 0 {
			r = int(o.param)
		}
		o1 = c.osr(p.As, int(p.From.Reg), int32(c.instoffset), r, int(p.Scond))

	case 21: /* mov/movbu O(R),R -> lr */
		c.aclass(&p.From)

		r := int(p.From.Reg)
		if r == 0 {
			r = int(o.param)
		}