Test.php

<?php

namespace Teste;

use \ErrorException;

class Test
{

	public function metodox(){

	}

}

set_error_handler(function ($errno, $errstr, $errfile, $errline ) {
		throw new \ErrorException($errstr, 0, $errno, $errfile, $errline);
	});

$start = 0;

$tick = function($msg='') use (&$start) {
	if (!$start) $start = microtime(1);
	else{
		$t = microtime(1);
		$diff = $t - $start;
		echo "<br>$msg $diff";
		$start = $t;
	}
};

$t = new Test();

$ini = microtime(1);
$metodo = array('metodox', 'metodoy');

$tick();

for ($x=0; $x<1000; $x++){
	if (!method_exists($t, $metodo[$x%2])) continue;
	$t->$metodo[$x%2]();
}
$tick('method_exists');

for ($x=0; $x<1000; $x++){
	try{
		$t->$metodo[$x%2]();
	}catch (Exception $e) { }
}
$tick('try');