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From: "rodgertq at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug libstdc++/101274] [11/12 Regression] std::execution::seq has incorrect behaviour under GCC 11.1.0 Date: Fri, 02 Jul 2021 01:03:03 +0000 [thread overview] Message-ID: <bug-101274-4-18kvVwsvkC@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-101274-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101274 --- Comment #4 from Thomas Rodgers <rodgertq at gcc dot gnu.org> --- I did some more reading of http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2020/n4878.pdf and it would seem that you are not even guaranteed a deterministic ordering of the application of binary_op on the non-execution policy accepting overloads of std::reduce(). See [reduce] the note at bullet 9 - "[Note 1 : The difference between reduce and accumulate is that reduce applies binary_op in an unspecified order, which yields a nondeterministic result for non-associative or non-commutative binary_op such as floating-point addition. — end note]"
next prev parent reply other threads:[~2021-07-02 1:03 UTC|newest] Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-06-30 16:08 [Bug c++/101274] New: " general at yhf8377 dot me 2021-06-30 16:09 ` [Bug c++/101274] " general at yhf8377 dot me 2021-07-01 7:17 ` [Bug libstdc++/101274] [11/12 Regression] " rguenth at gcc dot gnu.org 2021-07-01 7:56 ` marxin at gcc dot gnu.org 2021-07-01 18:54 ` rodgertq at gcc dot gnu.org 2021-07-02 1:03 ` rodgertq at gcc dot gnu.org [this message] 2021-07-02 12:00 ` general at yhf8377 dot me 2021-07-02 16:47 ` rodgertq at gcc dot gnu.org
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