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 52F823858005; Sun, 25 Jul 2021 05:07:31 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 52F823858005
From: "pinskia at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/80588] GCC can't simplify static inline
 function with xor/xnor
Date: Sun, 25 Jul 2021 05:07:31 +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: 7.0
X-Bugzilla-Keywords: missed-optimization
X-Bugzilla-Severity: enhancement
X-Bugzilla-Who: pinskia at gcc dot gnu.org
X-Bugzilla-Status: ASSIGNED
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: pinskia at gcc dot gnu.org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: cf_reconfirmed_on everconfirmed bug_status
 assigned_to
Message-ID: <bug-80588-4-6JJpjwHpxT@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-80588-4@http.gcc.gnu.org/bugzilla/>
References: <bug-80588-4@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: Sun, 25 Jul 2021 05:07:31 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D80588

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2021-07-25
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |ASSIGNED
           Assignee|unassigned at gcc dot gnu.org      |pinskia at gcc dot =
gnu.org

--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
On the trunk the only one missing is test2b:
  _8 =3D a_4(D) !=3D 0;
  _9 =3D b_3(D) !=3D 0;
  _10 =3D _8 ^ _9;
  _1 =3D ~_10;
  _7 =3D _8 =3D=3D _9;
  _2 =3D _1 =3D=3D _7;
  _5 =3D (int) _2;

If _7 is converted to _8 ^ _9
we would see _7 and _10 are the same
  _10 =3D _8 ^ _9;
  _1 =3D ~_10;
  _7 =3D _10;
  _2 =3D _1 ^ _7;

And then you have:
(~_10 ^ _10)
Which is always 1
And done.

So:

(simplify
 (eq truth_value@0 truth_value@1)
 (bit_xor @0 @1))
(simplify
 (ne truth_value@0 truth_value@1)
 (bit_xor (bit_xor @0 @1)) { build_one_cst (type); })=