Online PHP editor | output for SiTnY

@ 2017-10-26T13:27:45Z

<?php

function roundup_pow2(int $v, int $p2): int
{
    $p2 = 2 ** $p2 - 1;
    return ($v + $p2) & ~$p2;
}

/* examples: round up to the multiple of 32 (2^5) */
echo roundup_pow2(31, 5), PHP_EOL;
echo roundup_pow2(32, 5), PHP_EOL;
echo roundup_pow2(33, 5), PHP_EOL;

/* and here's how you align your strings using it */
$test = "12345";    /* let's align this to 4 chars boundary */
echo str_pad($test, roundup_pow2(strlen($test), 2), "0", STR_PAD_LEFT), PHP_EOL;

Output for 7.0.0 - 7.0.25, 7.1.0 - 7.1.20, 7.2.6 - 7.2.33, 7.3.16 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.4, 8.3.6: 32 32 64 00012345
Output for 8.3.5: Warning: PHP Startup: Unable to load dynamic library 'sodium.so' (tried: /usr/lib/php/8.3.5/modules/sodium.so (libsodium.so.23: cannot open shared object file: No such file or directory), /usr/lib/php/8.3.5/modules/sodium.so.so (/usr/lib/php/8.3.5/modules/sodium.so.so: cannot open shared object file: No such file or directory)) in Unknown on line 0 32 32 64 00012345

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