#25877 [Opn->Csd]: >> operator bug for negative LOP

ID: 25877 Updated by: vrana@php.net Reported By: cestmirl at freeside dot sk -Status: Open +Status: Closed Bug Type: Documentation problem Operating System: Linux Debian, Win32 PHP Version: 4.3.3 New Comment: This bug has been fixed in the documentation's XML sources. Since the online and downloadable versions of the documentation need some time to get updated, we would like to ask you to be a bit patient. Thank you for the report, and for helping us make our documentation better. "Don't right shift for more than 32 bits on 32 bits systems. Don't left shift in case it results to number longer than 32 bits." Previous Comments: ------------------------------------------------------------------------ [2003-10-16 11:22:49] jay@php.net Yeah, that would probably be a good idea. Maybe just a note that this sort of behaviour is undefined. We should probably check to see how it acts on Windows, too. (I don't have a Win box in front of me at the moment so if anybody could check...) J ------------------------------------------------------------------------ [2003-10-15 19:55:56] moriyoshi@php.net You may want to see the following thread brought up in the past at the php internals list: http://marc.theaimsgroup.com/?l=php-dev&m=103530736509081&w=2 Anyway, Jay, do you think it is more than enough to add a slight comment on the relevant page that the opeators cannot be used for unsigned operation? I see no reason to bogusify this as I regard this as a documentation problem. ------------------------------------------------------------------------ [2003-10-15 12:57:34] cestmirl at freeside dot sk You're right, it's the same semantics as GCC or Java has for signed int (though I've never experienced this yet as I've raised in Pascal world...). However, in this case, I think it's worth considering to implement Java unsigned shift ops (<<<, >>>) in PHP. Of course, there's no problem to mask out appropriate number of bits from left after making "signed shift" right, but standard operator would be much cleaner solution. ------------------------------------------------------------------------ [2003-10-15 11:54:01] jay@php.net This is expected. (1 << 31) wraps the 32-bit integer limit, and I believe this behaviour is undefined, at least in C and C++. If you run the same code in C or C++, the result is the same as what you're experiencing. J ------------------------------------------------------------------------ [2003-10-15 08:00:22] moriyoshi@php.net Heh, who told me that C supports '>>>' operator... there's no such operator in that language. ------------------------------------------------------------------------ The remainder of the comments for this report are too long. To view the rest of the comments, please view the bug report online at http://bugs.php.net/25877 -- Edit this bug report at http://bugs.php.net/?id=25877&edit=1