#49947 [NEW]: Looks like overlow

From: haochen at pristineprinting dot com Operating system: CentOS 5.3 PHP version: 5.2.11 PHP Bug Type: Math related Bug description: Looks like overlow Description: ------------ It looks like overflow when I do plus 1. But when I do tims 2, it looks correct. Strange! I guess times and division move left or right for binery number(...1011101...). Plus and minus functions maybe have bugs? I don't know my code is wrong or it is a bug. Server is Centos 5.3+PHP 5.2.11+Apache = Web Server I just put this code into public_html And client is WinXP+SP3+IE7. IE open the php. Wrong result. Thanks a lot. Reproduce code: --------------- <?php $x=2; $p=100; $y=pow($x,$p); $a=number_format($y); $b=$y+2; $c=$y*2; $r=number_format($a); $rr=number_format($b); echo "pow($x,$p) = $a <br><br>"; echo "pow($x,$p)+2 = $r <br><br>"; echo "pow($x,$p)*2 = $rr <br><br>"; ?> Expected result: ---------------- pow(2,100) = 1,267,650,600,228,229,401,496,703,205,376 pow(2,100)+2 = 1,267,650,600,228,229,401,496,703,205,378 pow(2,100)*2 = 2,535,301,200,456,458,802,993,406,410,752 Actual result: -------------- pow(2,100) = 1,267,650,600,228,229,401,496,703,205,376 pow(2,100)+2 = 1,267,650,600,228,229,401,496,703,205,376 pow(2,100)*2 = 2,535,301,200,456,458,802,993,406,410,752 -- Edit bug report at http://bugs.php.net/?id=49947&edit=1 -- Try a snapshot (PHP 5.2): http://bugs.php.net/fix.php?id=49947&r=trysnapshot52 Try a snapshot (PHP 5.3): http://bugs.php.net/fix.php?id=49947&r=trysnapshot53 Try a snapshot (PHP 6.0): http://bugs.php.net/fix.php?id=49947&r=trysnapshot60 Fixed in SVN: http://bugs.php.net/fix.php?id=49947&r=fixed Fixed in SVN and need be documented: http://bugs.php.net/fix.php?id=49947&r=needdocs Fixed in release: http://bugs.php.net/fix.php?id=49947&r=alreadyfixed Need backtrace: http://bugs.php.net/fix.php?id=49947&r=needtrace Need Reproduce Script: http://bugs.php.net/fix.php?id=49947&r=needscript Try newer version: http://bugs.php.net/fix.php?id=49947&r=oldversion Not developer issue: http://bugs.php.net/fix.php?id=49947&r=support Expected behavior: http://bugs.php.net/fix.php?id=49947&r=notwrong Not enough info: http://bugs.php.net/fix.php?id=49947&r=notenoughinfo Submitted twice: http://bugs.php.net/fix.php?id=49947&r=submittedtwice register_globals: http://bugs.php.net/fix.php?id=49947&r=globals PHP 4 support discontinued: http://bugs.php.net/fix.php?id=49947&r=php4 Daylight Savings: http://bugs.php.net/fix.php?id=49947&r=dst IIS Stability: http://bugs.php.net/fix.php?id=49947&r=isapi Install GNU Sed: http://bugs.php.net/fix.php?id=49947&r=gnused Floating point limitations: http://bugs.php.net/fix.php?id=49947&r=float No Zend Extensions: http://bugs.php.net/fix.php?id=49947&r=nozend MySQL Configuration Error: http://bugs.php.net/fix.php?id=49947&r=mysqlcfg