New submission from Serhiy Storchaka <storchaka+cpyt...@gmail.com>:
sum() assumes that an arithmetic operation on signed longs will wrap modulo 2**(bits_in_long) on overflow. However, signed overflow causes undefined behaviour according to the C standards (e.g., C99 6.5, para. 5), and gcc is known to assume that signed overflow never occurs in correct code, and to make use of this assumption when optimizing. See also issue7406. ---------- components: Interpreter Core messages: 341374 nosy: mark.dickinson, rhettinger, serhiy.storchaka priority: normal severity: normal status: open title: sum() relies on C signed overflow behaviour type: behavior versions: Python 3.7, Python 3.8 _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue36791> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
