Performance impact of using global $post

Question

I have two functions that do the same action: they add a title prefix for expired posts. Which of these functions will affect more the site performance?

function expired_facebook_events_title_prefix_( $title, $id = null ) {

    if( is_singular( 'facebook_events' ) && 'expired' == get_post_status() && in_the_loop() ) {
        return '[expirat] ' . $title;
    }

    return $title;
}
add_filter('the_title', 'expired_facebook_events_title_prefix_', 10, 2);


function expired_facebook_events_title_prefix( $title ) {
    global $post;
    if( $post->post_type == 'facebook_events' && $post->post_status == 'expired' && in_the_loop() ){
        return '[expirat] ' . $title;
   }
   return $title;
}
add_filter( 'the_title', 'expired_facebook_events_title_prefix' );

Answer 1

There is no significant difference. Both will use a cached version of the current $post, in one you will access it via global $post, in other via functions that will get the data from the $post in the cache. I would suggest moving the in_the_loop() condition to be first in the IF.