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 48D5B3890415; Mon, 26 Apr 2021 09:21:35 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 48D5B3890415
From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/100260] DSE: join stores
Date: Mon, 26 Apr 2021 09:21:35 +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: 11.0
X-Bugzilla-Keywords: missed-optimization
X-Bugzilla-Severity: normal
X-Bugzilla-Who: rguenth 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: everconfirmed bug_status cc cf_reconfirmed_on
Message-ID: <bug-100260-4-QJrlawcU80@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-100260-4@http.gcc.gnu.org/bugzilla/>
References: <bug-100260-4@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: Mon, 26 Apr 2021 09:21:35 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D100260

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW
                 CC|                            |ebotcazou at gcc dot gnu.o=
rg,
                   |                            |jakub at gcc dot gnu.org
   Last reconfirmed|                            |2021-04-26

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Confirmed.  store-merging doesn't seem to consider memset() as candidate to
merge with:

Processing basic block <2>:
Starting active chain number 1 with statement:
s_pam.size =3D 1;
The base object is:
&s_pam
stmt causes chain termination:
_1 =3D use (&s_pam);
Terminating chain with 1 stores

unsigned int foo ()
{
  struct pam s_pam;
  int _1;
  unsigned int _6;

  <bb 2> [local count: 1073741824]:
  memset (&s_pam, 0, 20);
  s_pam.size =3D 1;
  _1 =3D use (&s_pam);
  _6 =3D (unsigned int) _1;
  s_pam =3D{v} {CLOBBER};
  return _6;

}=