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 6E9313858035; Thu, 11 Nov 2021 00:21:31 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 6E9313858035
From: "navidrahimi at microsoft dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/101955] (signed<<31)>>31 should become -(signed&1)
Date: Thu, 11 Nov 2021 00:21:31 +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: 12.0
X-Bugzilla-Keywords: easyhack, missed-optimization
X-Bugzilla-Severity: enhancement
X-Bugzilla-Who: navidrahimi at microsoft 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: <bug-101955-4-1BtMsm2wSp@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-101955-4@http.gcc.gnu.org/bugzilla/>
References: <bug-101955-4@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, 11 Nov 2021 00:21:31 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D101955

navidrahimi <navidrahimi at microsoft dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |navidrahimi at microsoft d=
ot com

--- Comment #5 from navidrahimi <navidrahimi at microsoft dot com> ---
I think rather than just=20

int f(int b)
{
    return (((b)<<31)>>31);
}

We should optimize long too:
int f(int b)
{
    return (((b)<<63)>>63);
}


1) https://compiler-explorer.com/z/dnrr54v4r=