How to compare two 64 bit numbers
<p>In PHP I have a 64 bit number which represents tasks that must be completed.  A second 64 bit number represents the tasks which have been completed:</p>

<pre><code>$pack_code = 1001111100100000000000000011111101001111100100000000000000011111
$veri_code = 0000000000000000000000000001110000000000000000000000000000111110
</code></pre>

<p>I need to compare the two and provide a percentage of tasks completed figure.  I could loop through both and find how many bits are set, but I don't know if this is the fastest way?</p>
