return false
	}
	return p.at('(', scanner.Int, ')') && lex.IsRegisterShift(p.input[p.inputPos+3].ScanToken)
}

// atRegisterExtension reports whether we are at the start of an ARM64 extended register.
// We have consumed the register or R prefix.
func (p *Parser) atRegisterExtension() bool {
	switch p.arch.Family {
	case sys.ARM64, sys.Loong64:
		// R1.xxx
		return p.peek() == '.'
	default:
		return false