From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugzilla@gcc.gnu.org>
Received: by sourceware.org (Postfix, from userid 48)
 id 833AC3846409; Thu, 12 May 2022 11:27:28 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 833AC3846409
From: "cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug libstdc++/105562] std::function<bool(char)>::_M_invoker may be
 used uninitialized in std::regex move with -fno-strict-aliasing
Date: Thu, 12 May 2022 11:27:28 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: libstdc++
X-Bugzilla-Version: 12.1.0
X-Bugzilla-Keywords: diagnostic, missed-optimization
X-Bugzilla-Severity: normal
X-Bugzilla-Who: cvs-commit at gcc dot gnu.org
X-Bugzilla-Status: ASSIGNED
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P2
X-Bugzilla-Assigned-To: rguenth at gcc dot gnu.org
X-Bugzilla-Target-Milestone: 12.2
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: 
Message-ID: <bug-105562-4-SgvEEqeQyt@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-105562-4@http.gcc.gnu.org/bugzilla/>
References: <bug-105562-4@http.gcc.gnu.org/bugzilla/>
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 <gcc-bugs.gcc.gnu.org>
List-Unsubscribe: <https://gcc.gnu.org/mailman/options/gcc-bugs>,
 <mailto:gcc-bugs-request@gcc.gnu.org?subject=unsubscribe>
List-Archive: <https://gcc.gnu.org/pipermail/gcc-bugs/>
List-Post: <mailto:gcc-bugs@gcc.gnu.org>
List-Help: <mailto:gcc-bugs-request@gcc.gnu.org?subject=help>
List-Subscribe: <https://gcc.gnu.org/mailman/listinfo/gcc-bugs>,
 <mailto:gcc-bugs-request@gcc.gnu.org?subject=subscribe>
X-List-Received-Date: Thu, 12 May 2022 11:27:28 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D105562

--- Comment #13 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Richard Biener <rguenth@gcc.gnu.org>:

https://gcc.gnu.org/g:94b8a37fa16f7638cc1965718f4ec71719506743

commit r13-340-g94b8a37fa16f7638cc1965718f4ec71719506743
Author: Richard Biener <rguenther@suse.de>
Date:   Thu May 12 12:13:29 2022 +0200

    tree-optimization/105562 - avoid uninit diagnostic with better FRE

    We can avoid some uninit diagnostics by making FRE disambiguate
    against CLOBBERs since any aliasing there would invoke undefined
    behavior for a read we are looking up.

    2022-05-12  Richard Biener  <rguenther@suse.de>

            PR tree-optimization/105562
            * tree-ssa-sccvn.cc (vn_reference_lookup_3): Disambiguate
            against all CLOBBER defs if there's not an obvious must-alias
            and we are not doing redundant store elimination.
            (vn_walk_cb_data::redundant_store_removal_p): New field.
            (vn_reference_lookup_pieces): Initialize it.
            (vn_reference_lookup): Add argument to specify if we are
            doing redundant store removal.
            (eliminate_dom_walker::eliminate_stmt): Specify we do.
            * tree-ssa-sccvn.h (vn_reference_lookup): Adjust.

            * g++.dg/warn/uninit-pr105562.C: New testcase.=