Wie viel Zeit kosten Funktionsaufrufe in PHP?

test.php

<?php

define('MAX', 10000);

$varianteA = '/tmp/varianteA.php';
$varianteB = '/tmp/varianteB.php';

function funcName($i) {
    $n = '';
    while ($i > 25) {
        $n = chr(($i % 26) + 97) . $n;
        $i = $i / 26;
    }
    return '_' . chr($i + 97) . $n;
}

/*** TEIL A ***/
$source = '<?php
ini_set("xdebug.max_nesting_level", ' . (MAX + 4) . ');';

$oldname = '$v = 12';
for ($i = 0; $i < MAX; $i++) {
    $name = funcName($i);
    $rnd = rand(-10, 10);
    $source .= '
function '.$name.'($z) {
        $z += ' . $rnd .';
        ' . $oldname . ';
        $z -= ' . $rnd .';
        return $z;
}';
    $oldname = '$z = ' . $name . '($z)';
}
$source .= '
$__a = microtime();
echo ' . $name . '(12) . "\n";
$__b = microtime();
$zeitA = $__b - $__a;
echo $zeitA . "\n";
';
file_put_contents($varianteA, $source);
echo $varianteA . " erzeugt\n";

/*** TEIL B ***/
$sourcePre = '<?php
$__a = microtime();
$z = 12;';
$sourcePost = '
echo $z . "\n";
$__b = microtime();
$zeitB = $__b - $__a;
echo $zeitB . "\n";
';

$oldname = '$z';
for ($i = 0; $i < MAX; $i++) {
    $name = '$' . funcName($i);
    $rnd = rand(-10, 10);
    $sourcePre = $sourcePre . '
' . $name . ' = ' . $oldname . ';
' . $name . ' += ' . $rnd . ';';
    $sourcePost = '
' . $name . ' -= ' . $rnd . ';
' . $oldname . ' = ' . $name . ';' . $sourcePost;
    $oldname = $name;
}
$source = $sourcePre . '
$z = 12;
' . $sourcePost;
file_put_contents($varianteB, $source);
echo $varianteB . " erzeugt\n";


/* Auswertung */
include($varianteA);
include($varianteB);
echo 'Mehrkosten durch die ' . MAX . ' Funktionsaufrufe: ' . ($zeitA - $zeitB) . "\n";
echo 'Macht pro Aufruf ' . ($zeitA - $zeitB) / MAX . "s\n";