From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 92C1E3858400; Tue, 14 Dec 2021 13:09:36 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 92C1E3858400 From: "kobalicek.petr at gmail dot com" To: gcc-bugs@gcc.gnu.org Subject: [Bug c++/103699] Reading or writing a constant unaligned value is wrongly optimized causing an incorrect result (GCC-11 and up) Date: Tue, 14 Dec 2021 13:09:36 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: c++ X-Bugzilla-Version: 11.0 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: kobalicek.petr at gmail dot com X-Bugzilla-Status: RESOLVED X-Bugzilla-Resolution: INVALID X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: gcc-bugs@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-bugs mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 14 Dec 2021 13:09:36 -0000 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D103699 --- Comment #15 from Petr --- Unfortunately GCC doesn't report any issues even with `-Wstrict-aliasing=3D= 1`. BTW now I know I must use the may_alias attribute to my satisfaction, and t= his is what I'm gonna do, however, from user perspective I'm not really happy as GCC does something very silently. Personally, I would be happier if my code doesn't compile at all than having it compiled with bugs.=