WordPress Conditional Tag for Login Page

WordPress have conditional tags. The Conditional Tags can be used in your Template files to change what content is displayed and how that content is displayed on a particular page depending on what conditions that page matches

Following conditional tag is specific to Login Page, that is currently not available on WordPress Codex

if ( in_array( $GLOBALS['pagenow'], array( 'wp-login.php', 'wp-register.php' ) ) ) {
//Conditional statement here