Test: tail recurison

Is using tail-end recursion (where the recursion happens at the end of the function) any better?

Historical Results

Based on (2) saved test runs, The test labeled "normal recursion" was (on average) the faster by 0.0509 seconds, (8.280% faster)

normal recursion 100%

tail recursion 91.72%

The normal recursion test took 0.5634 seconds.
The tail recursion test took 0.6143 seconds.

Nitty-Gritty

Each test case ran 20 random code order iterations consisting of 133,628 loops for a total of 2,672,550 runs.

Line execution difference (0.000019) milliseconds.
Avg difference (0.000) milliseconds per 133,628 loops.
Total difference 50.87 milliseconds for 2,672,550 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, "normal recursion", was:

/*
function recurse_tail($i, $inside)
{
	$data = '<div>' . $inside . '</div>';

	if ($i <= 0)
		return $data;
	else
		return recurse_tail($i - 1, $data);
}
*/

$result = recurse_tail(200, '');

The second test, "tail recursion", was:

/*
function recurse_normal($i, $inside)
{
	$data = '<div>';
	if ($i <= 0)
		$data .= $inside;
	else
		$data .= recurse_normal($i - 1, $data);
	$data .= '</div>';

	return $data;
}
*/

$result = recurse_normal(200, '');

PHP Benchmarks