Description:
------------
Bit operation on php 5.6+ is lower performance than php 5.5-.
php5.5 is faster 3x+ than php5.6 and php7.0.

$ php5 -v
PHP 5.5.31 (cli) (built: Feb 20 2016 20:33:10) 
Copyright (c) 1997-2015 The PHP Group
Zend Engine v2.5.0, Copyright (c) 1998-2015 Zend Technologies

$php5 demo.php 
Done in 0.047697067260742 seconds

$ php -v
PHP 5.6.19 (cli) (built: Mar  6 2016 14:18:03) 
Copyright (c) 1997-2016 The PHP Group
Zend Engine v2.6.0, Copyright (c) 1998-2016 Zend Technologies
    with Xdebug v2.4.0, Copyright (c) 2002-2016, by Derick Retinas

$ php demo.php 
Done in 0.15873312950134 seconds

$ php7 -v
PHP 7.0.4 (cli) (built: Mar  6 2016 14:30:59) ( NTS )
Copyright (c) 1997-2016 The PHP Group
Zend Engine v3.0.0, Copyright (c) 1998-2016 Zend Technologies
    with Zend OPcache v7.0.6-dev, Copyright (c) 1999-2016, by Zend Technologies
    with Xdebug v2.4.0RC4-dev, Copyright (c) 2002-2015, by Derick Rethans

$ php7 demo.php 
Done in 0.10964512825012 seconds

Test script:
---------------
<?php
function microtime_float()
{
   list($usec, $sec) = explode(" ", microtime());
   return ((float)$usec + (float)$sec);
}

$time_start = microtime_float();


$i = 1920 * 1080;
$a = 1;
while ($i--) {
        $a << 1;
}

$time_end = microtime_float();
$time = $time_end - $time_start;

echo "Done in $time seconds\n";

Expected result:
----------------
Bit operation on php7.0 as faster as php5.5 or even better.

Actual result:
--------------
Low performance with bit operation on php7.0.