#47422 [Opn->Csd]: modulus operator returns incorrect results on 64 bit linux

ID: 47422 Updated by: mattwil@php.net Reported By: d_kelsey at uk dot ibm dot com -Status: Open +Status: Closed Bug Type: Scripting Engine problem Operating System: Linux 64Bit PHP Version: 5.2CVS-2009-02-17 (CVS) New Comment: This bug has been fixed in CVS. Snapshots of the sources are packaged every three hours; this change will be in the next snapshot. You can grab the snapshot at http://snaps.php.net/. Thank you for the report, and for helping us make PHP better. Thanks. Actually, just -1 needs to be checked there anyway, since only when doing LONG_MIN % -1 (in PHP, "(-PHP_INT_MAX - 1) % -1;") would there be a crash/error (which that's there to catch of course). Previous Comments: ------------------------------------------------------------------------ [2009-02-17 12:36:14] d_kelsey at uk dot ibm dot com Description: ------------ on a 64bit system the following var_dump(1%4294967295); should return 1, but returns 0. The problem is in the ZEND_API int mod_function(...) in zend_operators.c A call is made to abs which expects a 32bit int and returns a 32bit int, but 4294967295 is > 32 bits in size so the abs call returns an incorrect value. A proposed fix is to change the line "if (abs(op2->value.lval) == 1) {" to "if (op2->value.lval == 1 || op2->value.lval == -1) {" ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=47422&edit=1