// ARM64 only.
	if p.arch.Family != sys.ARM64 {
		return false
	}
	// R1.xxx
	return p.peek() == '.'
}

// 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] {