Description:
------------
very slow hash('sha1', ...)

Test script:
---------------
<?php
 $i=2000000;

 $x=sha1(microtime(1).mt_rand());

 $time_a=microtime(true);
 for($z=0;$z<$i;$z++){
  $a=sha1($x);
 }
 $time_a=microtime(true)-$time_a;

 $time_b=microtime(true);
 for($z=0;$z<$i;$z++){
  $b=hash('sha1',$x);
 }
 $time_b=microtime(true)-$time_b;

 $time_c=microtime(true);
 for($z=0;$z<$i;$z++){
  $c=hash('sha1',$x,true);
 }
 $time_c=microtime(true)-$time_c;

 print($time_a.' sec');
 print('<br/>');
 print($time_b.' sec');
 print('<br/>');
 print($time_c.' sec');
?>

Expected result:
----------------
0.98706293106079 sec
<=0.98706293106079 sec
<=0.98706293106079 sec

Actual result:
--------------
0.98706293106079 sec
1.248526096344 sec
1.1808590888977 sec