<?php
declare(strict_types = 1);
namespace BaconQrCode\Common;
/**
* General bit utilities.
*
* All utility methods are based on 32-bit integers and also work on 64-bit
* systems.
*/
final class BitUtils
{
private function __construct()
{
}
/**
* Performs an unsigned right shift.
*
* This is the same as the unsigned right shift operator ">>>" in other
* languages.
*/
public static function unsignedRightShift(int $a, int $b) : int
{
return (
$a >= 0
? $a >> $b
: (($a & 0x7fffffff) >> $b) | (0x40000000 >> ($b - 1))
);
}
/**
* Gets the number of trailing zeros.
*/
public static function numberOfTrailingZeros(int $i) : int
{
$lastPos = strrpos(str_pad(decbin($i), 32, '0', STR_PAD_LEFT), '1');
return $lastPos === false ? 32 : 31 - $lastPos;
}
}