PHP page perfomance test by time

<?php

function processing_time($START=false)
{
$an = 4; // How much digit return after point

if(!$START) return time() + microtime();
$END = time() + microtime();
return round($END – $START, $an);
}

?>

<?php
require_once “./pageload.php”;
$START = processing_time();

#####some code here########

$RESULT = processing_time($START);
echo $RESULT;

?>

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