Test: create_function vs. func callback

Using a pre-created function, is there any penalty in calling it versus a regular free function using a callback?

Historical Results

Based on (6) saved test runs, The test labeled "create_function()" was (on average) the faster by 0.0133 seconds, (1.777% faster)

create_function() 100%

regular callback 98.223%

The create_function() test took 0.7343 seconds.
The regular callback test took 0.7475 seconds.

Nitty-Gritty

Each test case ran 20 random code order iterations consisting of 146,826 loops for a total of 2,936,513 runs.

Line execution difference (0.000005) milliseconds.
Avg difference (0.000) milliseconds per 146,826 loops.
Total difference 13.28 milliseconds for 2,936,513 loops

The iteration variablity for Code 1 was (0.0000) milliseconds and Code 2 was (0.0000) milliseconds. The lower and the closer together there values are the more accurate the results are.

Code

The first test, "create_function()", was:

/*
$GLOBALS['dummy'] = create_function('', '
	$x = 0;
	$x += 5;

	if ($x >= 5)
		$x = 0;

	$x;
	$x;');
*/

$GLOBALS['dummy']();

The second test, "regular callback", was:

/*
function dummy()
{
	$x = 0;
	$x += 5;

	if ($x >= 5)
		$x = 0;

	$x;
	$x;
}
$GLOBALS['dummy_cb'] = 'dummy';
*/

$GLOBALS['dummy_cb']();

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