#45953 [NEW]: Sign-Bit Manipulating is buggy
| From: | ben at umingo dot de | Date: | Sat, 30 Aug 2008 10:23:30 +0000 |
| Subject: | #45953 [NEW]: Sign-Bit Manipulating is buggy | ||
| Groups: | php.bugs | ||
| Request: | Send a blank email to php-bugs+get-128548@lists.php.net to get a copy of this message | ||
From: ben at umingo dot de
Operating system: Windows XP 32Bit
PHP version: 5.2.6
PHP Bug Type: Output Control
Bug description: Sign-Bit Manipulating is buggy
Description:
------------
Problem is with sign bit.
If i have 0x81234567 then first bit is set to 1 (sign bit).
I would expect that number to be negative, as all integers are signed 32
bit integers.
If i echo that number, it is positive!
If i compute something with this number, it turns negative!
I have a standard PHP 5.2.6 Version and did not modify anything at it.
Reproduce code:
---------------
<?
//sign bit is not handled correctly
//a | a is expected to be a ...
//WORKS NOT
echo "with sign bit <br>";
echo (0x81234567 | 0x81234567); //result is negative
echo "<br>";
echo (0x81234567 );//result is positive
echo "<br>without sign bit <br>";
//WORKS
echo (0x71234567 | 0x71234567);
echo "<br>";
echo (0x71234567 );
?>
Expected result:
----------------
with sign bit
-2128394905
-2128394905
without sign bit
1898136935
1898136935
Actual result:
--------------
with sign bit
-2128394905
2166572391
without sign bit
1898136935
1898136935
--
Edit bug report at http://bugs.php.net/?id=45953&edit=1
--
Try a CVS snapshot (PHP 5.2): http://bugs.php.net/fix.php?id=45953&r=trysnapshot52
Try a CVS snapshot (PHP 5.3): http://bugs.php.net/fix.php?id=45953&r=trysnapshot53
Try a CVS snapshot (PHP 6.0): http://bugs.php.net/fix.php?id=45953&r=trysnapshot60
Fixed in CVS: http://bugs.php.net/fix.php?id=45953&r=fixedcvs
Fixed in release: http://bugs.php.net/fix.php?id=45953&r=alreadyfixed
Need backtrace: http://bugs.php.net/fix.php?id=45953&r=needtrace
Need Reproduce Script: http://bugs.php.net/fix.php?id=45953&r=needscript
Try newer version: http://bugs.php.net/fix.php?id=45953&r=oldversion
Not developer issue: http://bugs.php.net/fix.php?id=45953&r=support
Expected behavior: http://bugs.php.net/fix.php?id=45953&r=notwrong
Not enough info: http://bugs.php.net/fix.php?id=45953&r=notenoughinfo
Submitted twice: http://bugs.php.net/fix.php?id=45953&r=submittedtwice
register_globals: http://bugs.php.net/fix.php?id=45953&r=globals
PHP 4 support discontinued: http://bugs.php.net/fix.php?id=45953&r=php4
Daylight Savings: http://bugs.php.net/fix.php?id=45953&r=dst
IIS Stability: http://bugs.php.net/fix.php?id=45953&r=isapi
Install GNU Sed: http://bugs.php.net/fix.php?id=45953&r=gnused
Floating point limitations: http://bugs.php.net/fix.php?id=45953&r=float
No Zend Extensions: http://bugs.php.net/fix.php?id=45953&r=nozend
MySQL Configuration Error: http://bugs.php.net/fix.php?id=45953&r=mysqlcfg