return &optab[p.Optab-1]
	}
	if len(p.RestArgs) > 3 {
		c.ctxt.Diag("too many RestArgs: got %v, maximum is 3\n", len(p.RestArgs))
		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)
	}

type Optab struct {
	as    obj.As // Opcode
	a1    uint8  // p.From argument (obj.Addr). p is of type obj.Prog.
	a2    uint8  // p.Reg argument (int16 Register)
	a3    uint8  // p.RestArgs[0]  (obj.AddrPos)
	a4    uint8  // p.RestArgs[1]
	a5    uint8  // p.RestARgs[2]
	a6    uint8  // p.To (obj.Addr)
	type_ int8   // cases in asmout below. E.g., 44 = st r,(ra+rb); 45 = ld (ra+rb), r
	size  int8   // Text space in bytes to lay operation

func unpackOps4(p *obj.Prog) (arg0, arg1, arg2, dst *obj.Addr) {
	return &p.From, &p.RestArgs[0].Addr, &p.RestArgs[1].Addr, &p.To
}

// unpackOps5 extracts 5 operands from p.
func unpackOps5(p *obj.Prog) (arg0, arg1, arg2, arg3, dst *obj.Addr) {
	return &p.From, &p.RestArgs[0].Addr, &p.RestArgs[1].Addr, &p.RestArgs[2].Addr, &p.To

const (
	REGFROM = 1
)

type Optab struct {
	as    obj.As
	a1    uint8 // Prog.From
	a2    uint8 // 2nd source operand, Prog.Reg or Prog.RestArgs[XXX]
	a3    uint8 // 3rd source operand, Prog.RestArgs[XXX]
	a4    uint8 // Prog.To
	a5    uint8 // 2nd destination operand, Prog.RegTo2 or Prog.RestArgs[XXX]
	type_ int8
	size_ int8 // the value of this field is not static, use the size() method to return the value
	param int16
	flag  int8