Online PHP editor | refs for SiTnY

<?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;