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 109753858D3C; Fri,  4 Feb 2022 11:58:45 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 109753858D3C
From: "rguenther at suse dot de" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/50883] [ARM] Suboptimal optimization for small structures
Date: Fri, 04 Feb 2022 11:58:44 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: target
X-Bugzilla-Version: 4.6.2
X-Bugzilla-Keywords: missed-optimization
X-Bugzilla-Severity: enhancement
X-Bugzilla-Who: rguenther at suse dot de
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: 
Message-ID: <bug-50883-4-wwaLdeBjgt@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-50883-4@http.gcc.gnu.org/bugzilla/>
References: <bug-50883-4@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: Fri, 04 Feb 2022 11:58:45 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D50883

--- Comment #13 from rguenther at suse dot de <rguenther at suse dot de> ---
On Fri, 4 Feb 2022, ebotcazou at gcc dot gnu.org wrote:

> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D50883
>=20
> Eric Botcazou <ebotcazou at gcc dot gnu.org> changed:
>=20
>            What    |Removed                     |Added
> -------------------------------------------------------------------------=
---
>                  CC|                            |ebotcazou at gcc dot gnu=
.org
>=20
> --- Comment #12 from Eric Botcazou <ebotcazou at gcc dot gnu.org> ---
> > Btw, I thought about this issue quite extensively together with Michael=
 Matz
> > and it's going to be a mess, in particular on the call side.  Represent=
ing
> > things on GIMPLE will also be fun.=20
>=20
> Is it really worth the hassle though for real-world code, i.e. as opposed=
 to
> toy examples, now that we have IPA-SRA and the like?

I've looked at this in the context of BB vectorization which can
cause awful code when parameters / return vars are participating
and GIMPLE represents things as memory but RTL not.

But no, I don't remember any case from SPEC where it makes a difference
in the end.  Judging from the amount of duplicates we get around
parameter / return issues people do run into this.=