func (p *Parser) address(operand []lex.Token) obj.Addr {
	p.start(operand)
	addr := obj.Addr{}
	p.operand(&addr)
	return addr
}

// parseScale converts a decimal string into a valid scale factor.
func (p *Parser) parseScale(s string) int8 {
	switch s {
	case "1", "2", "4", "8":
		return int8(s[0] - '0')
	}
	p.errorf("bad scale: %s", s)
	return 0
}