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- apparently some systems can't handle floating point numbers defined directly (thanks, sjarkie!)

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git-svn-id: http://phpseclib.svn.sourceforge.net/svnroot/phpseclib/trunk@48 21d32557-59b3-4da0-833f-c5933fad653e
This commit is contained in:
Jim Wigginton 2009-10-02 21:34:13 +00:00
parent 8b1265d27c
commit 91a9079cf9
1 changed files with 11 additions and 4 deletions
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15
phpseclib/Math/BigInteger.php
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@ -69,7 +69,7 @@
* @author Jim Wigginton <terrafrost@php.net> * @author Jim Wigginton <terrafrost@php.net>
* @copyright MMVI Jim Wigginton * @copyright MMVI Jim Wigginton
* @license http://www.gnu.org/licenses/lgpl.txt * @license http://www.gnu.org/licenses/lgpl.txt
* @version $Id: BigInteger.php,v 1.11 2009-09-02 19:20:48 terrafrost Exp $ * @version $Id: BigInteger.php,v 1.12 2009-10-02 21:34:13 terrafrost Exp $
* @link http://pear.php.net/package/Math_BigInteger * @link http://pear.php.net/package/Math_BigInteger
*/ */
@ -150,6 +150,13 @@ define('MATH_BIGINTEGER_MODE_BCMATH', 2);
define('MATH_BIGINTEGER_MODE_GMP', 3); define('MATH_BIGINTEGER_MODE_GMP', 3);
/**#@-*/ /**#@-*/
/**
* The largest digit that may be used in addition / subtraction
*
* @access private
*/
define('MATH_BIGINTEGER_MAX_DIGIT52', pow(2, 52));
/** /**
* Pure-PHP arbitrary precision integer arithmetic library. Supports base-2, base-10, base-16, and base-256 * Pure-PHP arbitrary precision integer arithmetic library. Supports base-2, base-10, base-16, and base-256
* numbers. * numbers.
@ -607,8 +614,8 @@ class Math_BigInteger {
for ($i = 0; $i < $size - 1; $i+=2) { for ($i = 0; $i < $size - 1; $i+=2) {
$sum = $x[$i + 1] * 0x4000000 + $x[$i] + $y[$i + 1] * 0x4000000 + $y[$i] + $carry; $sum = $x[$i + 1] * 0x4000000 + $x[$i] + $y[$i + 1] * 0x4000000 + $y[$i] + $carry;
$carry = $sum >= 4503599627370496; // eg. floor($sum / 2**52); only possible values (in any base) are 0 and 1 $carry = $sum >= MATH_BIGINTEGER_MAX_DIGIT52; // eg. floor($sum / 2**52); only possible values (in any base) are 0 and 1
$sum = $carry ? $sum - 4503599627370496 : $sum; $sum = $carry ? $sum - MATH_BIGINTEGER_MAX_DIGIT52 : $sum;
$temp = floor($sum / 0x4000000); $temp = floor($sum / 0x4000000);
@ -709,7 +716,7 @@ class Math_BigInteger {
for ($i = 0; $i < $size - 1; $i+=2) { for ($i = 0; $i < $size - 1; $i+=2) {
$sum = $x[$i + 1] * 0x4000000 + $x[$i] - $y[$i + 1] * 0x4000000 - $y[$i] + $carry; $sum = $x[$i + 1] * 0x4000000 + $x[$i] - $y[$i + 1] * 0x4000000 - $y[$i] + $carry;
$carry = $sum < 0 ? -1 : 0; // eg. floor($sum / 2**52); only possible values (in any base) are 0 and 1 $carry = $sum < 0 ? -1 : 0; // eg. floor($sum / 2**52); only possible values (in any base) are 0 and 1
$sum = $carry ? $sum + 4503599627370496 : $sum; $sum = $carry ? $sum + MATH_BIGINTEGER_MAX_DIGIT52 : $sum;
$temp = floor($sum / 0x4000000); $temp = floor($sum / 0x4000000);