Converting IP address ranges into CIDR format

/****************************************************************************************************************/
/* Description: This snippet is provide simple way to help user Converting IP address ranges into CIDR format   */
/*              suggestions for different city locations across the country.                                    */
/*              There are 1 steps in this snippet. For information, please visit IP2Location tutorial page at:  */
/*https://www.ip2location.com/tutorials/how-to-convert-ip-address-range-into-cidr                               */
/****************************************************************************************************************/

<?php
    function iprange2cidr($ipStart, $ipEnd){
        if (is_string($ipStart) || is_string($ipEnd)){
            $start = ip2long($ipStart);
            $end = ip2long($ipEnd);
        }
        else{
            $start = $ipStart;
            $end = $ipEnd;
        }

        $result = array();

        while($end >= $start){
            $maxSize = 32;
            while ($maxSize > 0){
                $mask = hexdec(iMask($maxSize - 1));
                $maskBase = $start & $mask;
                if($maskBase != $start) break;
                $maxSize--;
            }
            $x = log($end - $start + 1)/log(2);
            $maxDiff = floor(32 - floor($x));

            if($maxSize < $maxDiff){
                $maxSize = $maxDiff;
            }

            $ip = long2ip($start);
            array_push($result, "$ip/$maxSize");
            $start += pow(2, (32-$maxSize));
        }
        return $result;
    }

    function iMask($s){
        return base_convert((pow(2, 32) - pow(2, (32-$s))), 10, 16);
    }

?>