From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id D4371385801D; Sat, 27 Mar 2021 21:32:12 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org D4371385801D From: "msebor at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug middle-end/57832] compiling sha-256 code (xz 5.0.5) generates false warnings when using -march=native on Atom CPU Date: Sat, 27 Mar 2021 21:32:12 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: middle-end X-Bugzilla-Version: 4.8.1 X-Bugzilla-Keywords: diagnostic X-Bugzilla-Severity: normal X-Bugzilla-Who: msebor at gcc dot gnu.org 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: 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: Sat, 27 Mar 2021 21:32:12 -0000 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D57832 --- Comment #6 from Martin Sebor --- In the reduced test cases (in comment #3 and comment #4) d is a global vari= able so it's value is zero. c is assigned in the first iteration of the loop (w= hen e is zero) and used in subsequent iterations when it has a defined value, so the warning .seems like a clear false postive to me. (I didn't look at the= big test case.)=