From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id 0BF733858C50; Tue, 29 Mar 2022 14:20:15 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 0BF733858C50 From: "mathieu.malaterre at gmail dot com" To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/102466] -O3 -fsanitize=undefined causes warnings (writing 2 bytes into a region of size 0) Date: Tue, 29 Mar 2022 14:20:14 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: tree-optimization X-Bugzilla-Version: 12.0 X-Bugzilla-Keywords: diagnostic X-Bugzilla-Severity: normal X-Bugzilla-Who: mathieu.malaterre at gmail dot com X-Bugzilla-Status: NEW X-Bugzilla-Resolution: 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: cc 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, 29 Mar 2022 14:20:15 -0000 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D102466 Mathieu Malaterre changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |mathieu.malaterre at gmail= dot com --- Comment #3 from Mathieu Malaterre = --- This is also triggered in libjxl codebase: * https://github.com/libjxl/libjxl/blob/main/tools/fuzzer_corpus.cc /usr/include/c++/11/bits/stl_algobase.h:431:30: warning: 'void* __builtin_memmove(void*, const void*, long unsigned int)' writing 1 or more bytes into a region of size 0 overflows the destination [-Wstringop-overflo= w=3D] 431 | __builtin_memmove(__result, __first, sizeof(_Tp) * _Num= ); | ~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~= ~=