Test: tail recurison

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

Historical Results

Based on (3) saved test runs, The test labeled "normal recursion" was (on average) the faster by 0.0147 seconds, (1.699% faster)

normal recursion 100%

tail recursion 98.301%

The normal recursion test took 0.8521 seconds.
The tail recursion test took 0.8668 seconds.

Nitty-Gritty

Each test case ran 20 random code order iterations consisting of 218,409 loops for a total of 4,368,173 runs.

Line execution difference (0.000003) milliseconds.
Avg difference (0.000) milliseconds per 218,409 loops.
Total difference 14.73 milliseconds for 4,368,173 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, '');

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