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 6FDB4385842F; Tue, 12 Oct 2021 18:37:41 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 6FDB4385842F
From: "cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug libstdc++/100387] ranges::minmax compares moved-out value
Date: Tue, 12 Oct 2021 18:37:41 +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: 12.0
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: cvs-commit at gcc dot gnu.org
X-Bugzilla-Status: ASSIGNED
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: ppalka at gcc dot gnu.org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: 
Message-ID: <bug-100387-4-rjxbPvbhjr@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-100387-4@http.gcc.gnu.org/bugzilla/>
References: <bug-100387-4@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: Tue, 12 Oct 2021 18:37:41 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D100387

--- Comment #6 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-10 branch has been updated by Patrick Palka
<ppalka@gcc.gnu.org>:

https://gcc.gnu.org/g:1335d35a530f31f60874cea1d5c98de81deed335

commit r10-10196-g1335d35a530f31f60874cea1d5c98de81deed335
Author: Patrick Palka <ppalka@redhat.com>
Date:   Fri Jun 18 19:33:39 2021 -0400

    libstdc++: Reduce ranges::minmax/minmax_element comparison complexity

    This rewrites ranges::minmax and ranges::minmax_element so that it
    performs at most 3*N/2 many comparisons, as required by the standard.
    In passing, this also fixes PR100387 by avoiding a premature std::move
    in ranges::minmax and in std::shift_right.

            PR libstdc++/100387

    libstdc++-v3/ChangeLog:

            * include/bits/ranges_algo.h (__minmax_fn::operator()): Rewrite
            to limit comparison complexity to 3*N/2.
            (__minmax_element_fn::operator()): Likewise.
            (shift_right): Avoid premature std::move of __result.
            * testsuite/25_algorithms/minmax/constrained.cc (test04, test05=
):
            New tests.
            * testsuite/25_algorithms/minmax_element/constrained.cc (test02=
):
            Likewise.

    (cherry picked from commit cc9c94d43dcfa98436152af9c00f011e9dab25f6)=