PHP int 超大溢出整数的 加减运算函数，如果有更好的方法欢迎探讨

【分享】PHP int 超大溢出整数的 加减运算函数，如果有更好的方法欢迎探讨
分享一个溢出整数加减的运算函数，刚刚写的，对于溢出的整数可以用这个来进行加减运算。
遗憾的几点是：

一代码太多；

二只有加减运算，乘除取余都没有；

mysql> SELECT 11234123413241341234123412341234+1;

+------------------------------------+

| 11234123413241341234123412341234+1 |

+------------------------------------+

|   11234123413241341234123412341235 |

+------------------------------------+

1 row in set (0.00 sec)



mysql> SELECT 11234123413241341234123412341234*12341234123;

+----------------------------------------------+

| 11234123413241341234123412341234*12341234123 |

+----------------------------------------------+

|   138642947209487270472850788378836360727782 |

+----------------------------------------------+

1 row in set (0.00 sec)

/* big int operate [by fuzb 20130826] */

function bigintO($num1,$op,$num2)

{

    $arr = array();

    $endop = '';

    $num1o = $num1;

    $num2o = $num2;

    if($num1 
    {

        $c1 = -1;

        $num1 = preg_replace('/^(-)/','',$num1);


    } else {

        $c1 = 1;

    }


    if($num2 
    {

        $c2 = -1;

        $num2 = preg_replace('/^(-)/','',$num2);

    } else {

        $c2 = 1;

    }


    $len1 = strlen($num1);

    $len2 = strlen($num2);

    $len = max(strlen($num1),strlen($num2));

    if($len1 
    if($len2 



    if($op == '+')

    {

        if($c1 == $c2)

        {