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 B59203858414; Tue, 16 Nov 2021 08:42:17 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org B59203858414
From: "tnfchris at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/103253] [12 Regression] ICE: Segmentation
 fault (in convert_mult_to_fma or in vect_recog_mask_conversion_pattern) since
 r12-5129-g8ed62c929c7c4462
Date: Tue, 16 Nov 2021 08:42:17 +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: 12.0
X-Bugzilla-Keywords: ice-on-valid-code
X-Bugzilla-Severity: normal
X-Bugzilla-Who: tnfchris at gcc dot gnu.org
X-Bugzilla-Status: ASSIGNED
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: tnfchris at gcc dot gnu.org
X-Bugzilla-Target-Milestone: 12.0
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: bug_status assigned_to
Message-ID: <bug-103253-4-iyXOUFoOV7@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-103253-4@http.gcc.gnu.org/bugzilla/>
References: <bug-103253-4@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, 16 Nov 2021 08:42:17 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D103253

Tamar Christina <tnfchris at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
           Assignee|unassigned at gcc dot gnu.org      |tnfchris at gcc dot=
 gnu.org

--- Comment #4 from Tamar Christina <tnfchris at gcc dot gnu.org> ---
Strange... I'll take a look.

It looks like the vectorizer has generated correct code even after this cha=
nge

  _54 =3D .COND_MUL (mask_patt_20.12_45, vect__1.9_38, { 2.0e+0, 2.0e+0, 2.=
0e+0,
2.0e+0, 2.0e+0, 2.0e+0, 2.0e+0, 2.0e+0 }, { 1.0e+0, 1.0e+0, 1.0e+0, 1.0e+0,
1.0e+0, 1.0e+0, 1.0e+0, 1.0e+0 });
  vect_patt_21.13_48 =3D _54;
  _55 =3D .COND_MUL (mask_patt_20.12_46, vect__1.9_39, { 2.0e+0, 2.0e+0, 2.=
0e+0,
2.0e+0, 2.0e+0, 2.0e+0, 2.0e+0, 2.0e+0 }, { 1.0e+0, 1.0e+0, 1.0e+0, 1.0e+0,
1.0e+0, 1.0e+0, 1.0e+0, 1.0e+0 });
  vect_patt_21.13_49 =3D _55;
  iftmp.0_3 =3D i_10 !=3D 0 ? iftmp.0_8 : 1.0e+0;
  # RANGE [1, 17] NONZERO 31
  i_9 =3D i_10 + 1;
  ivtmp_2 =3D ivtmp_4 - 1;
  ivtmp_53 =3D ivtmp_52 + 1;
  if (ivtmp_53 < 1)

but DCE6 mangles this to invalid gimple:

  .COND_MUL (mask_patt_20.12_45, vect__1.9_38, { 2.0e+0, 2.0e+0, 2.0e+0,
2.0e+0, 2.0e+0, 2.0e+0, 2.0e+0, 2.0e+0 }, { 1.0e+0, 1.0e+0, 1.0e+0, 1.0e+0,
1.0e+0, 1.0e+0, 1.0e+0, 1.0e+0 });
  .COND_MUL (mask_patt_20.12_46, vect__1.9_39, { 2.0e+0, 2.0e+0, 2.0e+0,
2.0e+0, 2.0e+0, 2.0e+0, 2.0e+0, 2.0e+0 }, { 1.0e+0, 1.0e+0, 1.0e+0, 1.0e+0,
1.0e+0, 1.0e+0, 1.0e+0, 1.0e+0 });
  ivtmp_53 =3D ivtmp_52 + 1;
  if (ivtmp_53 < 1)


it removes the dead statements but removes the SSA var _55 without removing
it's definition.=