array_values vs array_keys + range + count

bench_range_vs_values.php

<?php

function range_keys($n, $data) {
    for ($i = 0; $i < $n; ++$i) {
        if ($data) {
            $r = array_keys($data) !== range(0, count($data) - 1);
        } else {
            $r = [];
        }
    }
}

function values($n, $data) {
    for ($i = 0; $i < $n; ++$i) {
        $r = array_values($data) !== $data;
    }
}

function empty_loop($n) {
    for ($i = 0; $i < $n; ++$i) {
    }
}

function getmicrotime()
{
    $t = gettimeofday();
    return ($t['sec'] + $t['usec'] / 1000000);
}

function start_test()
{
    ob_start();
    return getmicrotime();
}

function end_test($start, $name, $overhead = null)
{
    global $total;
    global $last_time;
    $end = getmicrotime();
    ob_end_clean();
    $last_time = $end-$start;
    $total += $last_time;
    $num = number_format($last_time,3);
    $pad = str_repeat(" ", 28 - strlen($name) - strlen($num));
    if (is_null($overhead)) {
        echo $name.$pad.$num."\n";
    } else {
        $num2 = number_format($last_time - $overhead, 3);
        echo $name.$pad.$num."    ".$num2."\n";
    }
    ob_start();
    return getmicrotime();
}

function total()
{
    global $total;
    $pad = str_repeat("-", 28);
    echo $pad."\n";
    $num = number_format($total,3);
    $pad = str_repeat(" ", 28 - strlen("Total")-strlen($num));
    echo "Total".$pad.$num."\n";
}

const N = 100000;

$t0 = $t = start_test();
empty_loop(N);
$t = end_test($t, 'empty_loop');
$overhead = $last_time;

// ========================
$size = 0;
$data = [];

values(N, $data);
$t = end_test($t, "values($size)", $overhead);

range_keys(N, $data);
$t = end_test($t, "range_keys($size)", $overhead);

// ========================
$size = 100;
$data = range(0, $size - 1);

values(N, $data);
$t = end_test($t, "values($size)", $overhead);

range_keys(N, $data);
$t = end_test($t, "range_keys($size)", $overhead);

// ========================
$size = 1000;
$data = range(0, $size - 1);

values(N, $data);
$t = end_test($t, "values($size)", $overhead);

range_keys(N, $data);
$t = end_test($t, "range_keys($size)", $overhead);

// ========================
$size = 10000;
$data = range(0, $size - 1);

values(N, $data);
$t = end_test($t, "values($size)", $overhead);

range_keys(N, $data);
$t = end_test($t, "range_keys($size)", $overhead);

// ========================
$size = 100;
$data = range(0, $size - 2);
$data['z'] = $size;

values(N, $data);
$t = end_test($t, "values($size)", $overhead);

range_keys(N, $data);
$t = end_test($t, "range_keys($size)", $overhead);

// ========================
$size = 1000;
$data = range(0, $size - 2);
$data['z'] = $size;

values(N, $data);
$t = end_test($t, "values($size)", $overhead);

range_keys(N, $data);
$t = end_test($t, "range_keys($size)", $overhead);

// ========================
$size = 10000;
$data = range(0, $size - 2);
$data['z'] = $size;

values(N, $data);
$t = end_test($t, "values($size)", $overhead);

range_keys(N, $data);
$t = end_test($t, "range_keys($size)", $overhead);

total();

output.txt

$ php tests/bench_range_vs_values.php
empty_loop             0.001
values(0)              0.005    0.005
range_keys(0)          0.002    0.001
values(100)            0.116    0.115
range_keys(100)        0.166    0.165
values(1000)           1.177    1.176
range_keys(1000)       2.001    2.000
values(10000)         12.136    12.136
range_keys(10000)     20.215    20.214
values(100)            0.125    0.124
range_keys(100)        0.173    0.172
values(1000)           1.183    1.183
range_keys(1000)       2.046    2.045
values(10000)         12.168    12.168
range_keys(10000)     20.260    20.260
----------------------------
Total                 71.775

$ php -v
PHP 7.0.5 (cli) (built: Apr 23 2016 10:48:01) ( NTS )
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Zend Engine v3.0.0, Copyright (c) 1998-2016 Zend Technologies
    with Zend OPcache v7.0.6-dev, Copyright (c) 1999-2016, by Zend Technologies