// see comments in func preprocess for details.
		o2 = 0

	case 7: /* mov r, soreg ==> sw o(r) */
		r := p.To.Reg
		if r == obj.REG_NONE {
			r = o.param
		}
		v := c.regoff(&p.To)
		o1 = OP_IRR(c.opirr(p.As), uint32(v), r, p.From.Reg)

	case 8: /* mov soreg, r ==> lw o(r) */
		r := p.From.Reg
		if r == obj.REG_NONE {
			r = o.param
		}
		v := c.regoff(&p.From)

		default:
			c.ctxt.Diag("unexpected branch encoding\n%v", p)
		}

	case 7: // mov r, soreg
		r := int(p.To.Reg)
		if r == 0 {
			r = int(o.param)
		}
		v := c.regoff(&p.To)
		o1 = OP_12IRR(c.opirr(p.As), uint32(v), uint32(r), uint32(p.From.Reg))

	case 8: // mov soreg, r
		r := int(p.From.Reg)
		if r == 0 {
			r = int(o.param)
		}
		v := c.regoff(&p.From)