chr vs pack

bench_chr_vs_pack.php

<?php

function pack_cc($n) {
    for ($i = 0; $i < $n; ++$i) {
        $num = \pack('CC', 0xcc, 200);
    }
}

function chr_cc($n) {
    for ($i = 0; $i < $n; ++$i) {
        $num = "\xcc".\chr(200);
    }
}

function pack_ccc($n) {
    for ($i = 0; $i < $n; ++$i) {
        $num = \pack('CCC', 0xc7, 100, 200);
    }
}

function chr_ccc($n) {
    for ($i = 0; $i < $n; ++$i) {
        $num = "\xcc".\chr(100).\chr(200);
    }
}

function pack_cn($n) {
    for ($i = 0; $i < $n; ++$i) {
        $num = \pack('Cn', 0xdc, 1234);
    }
}

function chr_cn($n) {
    for ($i = 0; $i < $n; ++$i) {
        $num = "\xdc".\chr(1234 >> 8).\chr(1234);
    }
}

function pack_cnc($n) {
    for ($i = 0; $i < $n; ++$i) {
        $num = \pack('CnC', 0xc8, 1234, 42);
    }
}

function chr_cnc($n) {
    for ($i = 0; $i < $n; ++$i) {
        $num = "\xc8".\chr(1234 >> 8).\chr(1234).\chr(42);
    }
}

function pack_w_chars($n) {
    for ($i = 0; $i < $n; ++$i) {
        $num = \pack('CnC', 0xc9, 1234, 42);
    }
}

function pack_wo_chars($n) {
    for ($i = 0; $i < $n; ++$i) {
        $num = "\xc9".\pack('n', 1234).\chr(42);
    }
}

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);
    $pad = str_repeat(" ", 24-strlen($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("-", 24);
    echo $pad."\n";
    $num = number_format($total,3);
    $pad = str_repeat(" ", 24-strlen("Total")-strlen($num));
    echo "Total".$pad.$num."\n";
}

const N = 10000000;

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

pack_cc(N);
$t = end_test($t, 'pack_cc', $overhead);

chr_cc(N);
$t = end_test($t, 'chr_cc', $overhead);

pack_ccc(N);
$t = end_test($t, 'pack_ccc', $overhead);

chr_ccc(N);
$t = end_test($t, 'chr_ccc', $overhead);

pack_cn(N);
$t = end_test($t, 'pack_cn', $overhead);

chr_cn(N);
$t = end_test($t, 'chr_cn', $overhead);

pack_cnc(N);
$t = end_test($t, 'pack_cnc', $overhead);

chr_cnc(N);
$t = end_test($t, 'chr_cnc', $overhead);

pack_w_chars(N);
$t = end_test($t, 'pack_w_chars', $overhead);

pack_wo_chars(N);
$t = end_test($t, 'pack_wo_chars', $overhead);

total();

output.txt

$ php tests/bench_chr_vs_pack.php
empty_loop         0.085
pack_cc            1.310    1.225
chr_cc             0.600    0.514
pack_ccc           1.452    1.366
chr_ccc            0.924    0.839
pack_cn            1.297    1.211
chr_cn             0.847    0.761
pack_cnc           1.494    1.409
chr_cnc            1.497    1.412
pack_w_chars       1.481    1.396
pack_wo_chars      1.813    1.728
------------------------
Total             12.801


$ php -v
PHP 7.0.5 (cli) (built: Apr 23 2016 10:48:01) ( NTS )
Copyright (c) 1997-2016 The PHP Group
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