ID: 38045 Updated by: [EMAIL PROTECTED] Reported By: igor at oleinikov dot ru -Status: Open +Status: Bogus Bug Type: Scripting Engine problem Operating System: FreeBSD 6.1 Release PHP Version: 5.1.4 New Comment:
Thank you for taking the time to write to us, but this is not a bug. Please double-check the documentation available at http://www.php.net/manual/ and the instructions on how to report a bug at http://bugs.php.net/how-to-report.php 32bit Previous Comments: ------------------------------------------------------------------------ [2006-07-09 09:30:38] igor at oleinikov dot ru Description: ------------ When I want to calculate integer summ of two integers with overflow, I get unexpected result, becouse result converts to float, then converts to integer. Important: I've tested this example on two systems with same versions of php (5.1.4) and different versions of freebsd (4.11 and 6.1). On last operation [$b = (int)($a + $a)], freebsd 4.11 produce expected result: int(0), but freebsd 6.1 produce minimal integer (-2147483648). How can I implement algorithm with integer mathematics, that requires overflows? i have it successfully working on freebsd 4.11, but it don't work on freebsd 6.1 (( Reproduce code: --------------- $a = 0x80000000; //i'd like it would integer, but it float ;) var_dump($a, dechex($a)); $a = (int)0x80000000; //ok, i'll make it integer myself var_dump($a, dechex($a)); $b = $a + $a; //int + int = int ? var_dump($b, dechex($b)); $b = (int)($a + $a); var_dump($b, dechex($b)); Expected result: ---------------- int(-2147483648) string(8) "80000000" int(-2147483648) string(8) "80000000" int(0) string(8) "0" //expected, int + int = int with overflow int(0) string(8) "0" //expected, conversion with overflow Actual result: -------------- float(2147483648) string(8) "80000000" // expected int int(-2147483648) string(8) "80000000" // when I convert to int myself float(-4294967296) string(8) "80000000" //expected int, but it overflows and converts to float int(-2147483648) string(8) "80000000" ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=38045&edit=1
