switch p.arch.Family {
	case sys.ARM64, sys.Loong64:
		// R1.xxx
		return p.peek() == '.'
	default:
		return false
	}
}

// registerReference parses a register given either the name, R10, or a parenthesized form, SPR(10).
func (p *Parser) registerReference(name string) (int16, bool) {
	r, present := p.arch.Register[name]
	if present {
		return r, true
	}
	if !p.arch.RegisterPrefix[name] {