Bug #80732 [Com]: The sum of two large integers lead to errors when overflow occurs.

Edit report at https://bugs.php.net/bug.php?id=80732&edit=1 ID: 80732 Comment by: 809721719 at qq dot com Reported by: 809721719 at qq dot com Summary: The sum of two large integers lead to errors when overflow occurs. Status: Not a bug Type: Bug Package: *General Issues Operating System: MacOS 10.14 (64bit) PHP Version: 7.4.15 Block user comment: N Private report: N New Comment: Thanks for helping! Previous Comments: ------------------------------------------------------------------------ [2021-02-11 18:12:35] requinix@php.net 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 https://www.php.net/manual/en/language.types.integer.php > If PHP encounters a number beyond the bounds of the int type, it will be > interpreted as a float instead. Also, an operation which results in a number > beyond the bounds of the int type will return a float instead. > When converting from float to int, the number will be rounded towards zero. > > If the float is beyond the boundaries of int (usually +/- 2.15e+9 = 2^31 on > 32-bit platforms and +/- 9.22e+18 = 2^63 on 64-bit platforms), the result is > undefined, since the float doesn't have enough precision to give an exact int > result. No warning, not even a notice will be issued when this happens! ------------------------------------------------------------------------ [2021-02-11 17:15:45] 809721719 at qq dot com Summary is modified. ------------------------------------------------------------------------ [2021-02-11 16:57:56] 809721719 at qq dot com Modification summary ------------------------------------------------------------------------ [2021-02-11 16:30:05] 809721719 at qq dot com Description: ------------ The addition of two integers exceeds the maximum value of the integer. After an overflow occurs, the resulting value is distorted. I test in C/C++/Go and got different results from PHP, but they get the same results. Test script: --------------- var_dump(intval(9223372036854775807 + 1)); // int(-9223372036854775808) var_dump(intval(9223372036854775807 + 2)); // int(-9223372036854775808) var_dump(intval(9223372036854775807 + 3)); // int(-9223372036854775808) Expected result: ---------------- int(-9223372036854775808) int(-9223372036854775807) int(-9223372036854775806) Actual result: -------------- int(-9223372036854775808) int(-9223372036854775808) int(-9223372036854775808) ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=80732&edit=1