From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id CBA713836028; Mon, 2 Aug 2021 08:38:32 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org CBA713836028 From: "rguenth at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug tree-optimization/101705] Missed optimization opportunity when copying lots of bitfields Date: Mon, 02 Aug 2021 08:38:32 +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: 11.1.1 X-Bugzilla-Keywords: missed-optimization X-Bugzilla-Severity: normal X-Bugzilla-Who: rguenth 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: blocked Message-ID: In-Reply-To: References: 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 List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 02 Aug 2021 08:38:32 -0000 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D101705 Richard Biener changed: What |Removed |Added ---------------------------------------------------------------------------- Blocks| |53947 --- Comment #4 from Richard Biener --- SLP vectorization handles this and it even splits the groups and would use smaller groups for the tail but then it fails: t.i:244:10: note: =3D=3D=3D vect_slp_analyze_instance_alignment =3D=3D=3D t.i:244:10: missed: desired vector type conflicts with earlier one for _1= 13 =3D s_129(D)->b113; t.i:244:10: note: removing SLP instance operations starting from: d_130(D)->b113 =3D _113; t.i:252:10: note: =3D=3D=3D vect_slp_analyze_instance_alignment =3D=3D=3D t.i:252:10: missed: desired vector type conflicts with earlier one for _1= 21 =3D s_129(D)->b121; t.i:252:10: note: removing SLP instance operations starting from: d_130(D)->b121 =3D _121; t.i:256:10: note: =3D=3D=3D vect_slp_analyze_instance_alignment =3D=3D=3D t.i:256:10: missed: desired vector type conflicts with earlier one for _1= 25 =3D s_129(D)->b125; t.i:256:10: note: removing SLP instance operations starting from: d_130(D)->b125 =3D _125; which is a pre-existing issue (and I think there's a duplicate for the vectorizer issue). Not sure what part Andrew wants to look at. Without vectorization we don't merge anything. Referenced Bugs: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D53947 [Bug 53947] [meta-bug] vectorizer missed-optimizations=