a2 = rclass(p.Reg)
	}

	a3 := C_NONE
	if p.GetFrom3() != nil {
		a3 = int(p.GetFrom3().Class)
		if a3 == 0 {
			a3 = c.aclass(p.GetFrom3())
			p.GetFrom3().Class = int8(a3)
		}
	}

	a4 := int(p.To.Class)
	if a4 == 0 {
		a4 = c.aclass(&p.To)
		if p.To.Type == obj.TYPE_MEM {
			if isMOVop(p.As) && (cmp(C_LAUTO, a4) || cmp(C_LOREG, a4)) {

		return &optab[a1-1]
	}
	a1 = int(p.From.Class)
	if a1 == 0 {
		a1 = c.aclass(&p.From) + 1
		p.From.Class = int8(a1)
	}
	a1--

	argsv := [3]int{C_NONE + 1, C_NONE + 1, C_NONE + 1}
	for i, ap := range p.RestArgs {
		argsv[i] = int(ap.Addr.Class)
		if argsv[i] == 0 {
			argsv[i] = c.aclass(&ap.Addr) + 1
			ap.Addr.Class = int8(argsv[i])
		}

	}
	a3 := argsv[0] - 1

		return nil
	}

	// Initialize classes for all arguments.
	p.From.Class = int8(c.aclass(&p.From) + 1)
	p.To.Class = int8(c.aclass(&p.To) + 1)
	for i := range p.RestArgs {
		p.RestArgs[i].Addr.Class = int8(c.aclass(&p.RestArgs[i].Addr) + 1)
	}

	// Mirrors the argument list in Optab.
	args := [...]int8{
		p.From.Class - 1,
		C_NONE, // p.Reg