Time to call parent class

With child method.php

<?php
class Foo
{
    //somes attributes and methods
    
    public function display()
    {
        //somes actions...
    }
}

class Bar extends Foo
{
    //somes attributes and methods
    
    public function display()
    {
        parent::display();
    }
}

$bar = new Bar;
$bar->display(); //Time 0.3sec

Without child method.php

<?php
class Foo
{
    //somes attributes and methods
    
    public function display()
    {
        //somes actions...
    }
}

class Bar extends Foo
{
    //somes attributes and methods
}

$bar = new Bar;
$bar->display(); //Time 1.2sec