run_shortcode() is a faster way to call individual shortcodes -- at least 4x faster on a vanilla install, speed increases to 10x or greater with the number of shortcodes registered

run_shortcode.php

<?php

// Faster replacement for do_shortcode *for individual shortcodes only*
// If you have nested shortcodes or shortcodes intermixed in content, do_shortcode() is the still the way to go.

// Inspired by: https://kovshenin.com/2013/dont-do_shortcode/
// WordPress Core Trac Ticket: https://core.trac.wordpress.org/ticket/25435

// Usage

// run_shortcode( 'test_shortcode' );
// VS
// do_shortcode( '[example_shortcode]' );
// NOT
// run_shortcode( 'This is a [test_shortcode].' ); // this will not work

// Optionally specify attributes and/or content

// run_shortcode( 'test_shortcode', array( 'foo' => 'bar'  ), 'content' );

if( ! function_exists( 'run_shortcode' ) ){
	function run_shortcode( $tag, $args = null, $content = null ){

		global $shortcode_tags;
		
		if( isset( $shortcode_tags[ $tag ] ) ){
			$func = $shortcode_tags[ $tag ];
		}

		if( ! empty( $func ) && function_exists( $func ) ){
			return call_user_func( $func, $args, $content, $tag );
		}

	}
}