function wp_exist_post_by_title( $title ) {
	global $wpdb;
	$return = $wpdb->get_row( "SELECT ID FROM wp_posts WHERE post_title = '" . $title . "' && post_status = 'publish' && post_type = 'post' ", 'ARRAY_N' );
	if( empty( $return ) ) {
		return false;
	} else {
		return true;
	}
}

// usage
if( wp_exist_post_by_title( $post->name ) ) {
	// post exist
} else { 
	// post does not exist
}