51 lines
1.1 KiB
PHP
Executable File
51 lines
1.1 KiB
PHP
Executable File
<?php
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/**
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* BaconQrCode
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*
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* @link http://github.com/Bacon/BaconQrCode For the canonical source repository
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* @copyright 2013 Ben 'DASPRiD' Scholzen
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* @license http://opensource.org/licenses/BSD-2-Clause Simplified BSD License
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*/
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namespace BaconQrCode\Common;
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/**
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* General bit utilities.
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*
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* All utility methods are based on 32-bit integers and also work on 64-bit
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* systems.
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*/
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class BitUtils
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{
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/**
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* Performs an unsigned right shift.
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*
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* This is the same as the unsigned right shift operator ">>>" in other
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* languages.
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*
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* @param integer $a
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* @param integer $b
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* @return integer
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*/
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public static function unsignedRightShift($a, $b)
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{
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return (
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$a >= 0
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? $a >> $b
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: (($a & 0x7fffffff) >> $b) | (0x40000000 >> ($b - 1))
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);
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}
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/**
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* Gets the number of trailing zeros.
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*
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* @param integer $i
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* @return integer
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*/
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public static function numberOfTrailingZeros($i)
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{
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$lastPos = strrpos(str_pad(decbin($i), 32, '0', STR_PAD_LEFT), '1');
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return $lastPos === false ? 32 : 31 - $lastPos;
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}
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} |