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 B6D883858426; Mon,  3 Jan 2022 10:26:29 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org B6D883858426
From: "rguenther at suse dot de" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/92860] [9/10/11/12 regression] Global flags
 affected by -O settings are clobbered by optimize attribute
Date: Mon, 03 Jan 2022 10:26:29 +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: 10.0
X-Bugzilla-Keywords: deferred, opt-attribute
X-Bugzilla-Severity: normal
X-Bugzilla-Who: rguenther at suse dot de
X-Bugzilla-Status: WAITING
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P2
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: 12.0
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: 
Message-ID: <bug-92860-4-DcZjAONBdt@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-92860-4@http.gcc.gnu.org/bugzilla/>
References: <bug-92860-4@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, 03 Jan 2022 10:26:29 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D92860

--- Comment #76 from rguenther at suse dot de <rguenther at suse dot de> ---
On Tue, 14 Dec 2021, marxin at gcc dot gnu.org wrote:

> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D92860
>=20
> --- Comment #75 from Martin Li=C5=A1ka <marxin at gcc dot gnu.org> ---
> (In reply to David Binderman from comment #74)
> > (In reply to Martin Li=C5=A1ka from comment #72)
> > > You will manage, it's not rocket science.
> > >=20
> > > So please, add break point at the place it triggers the ICE and do:
> > >=20
> > > (gdb) p &ptr1->x_help_flag
> > > (gdb) p &ptr2->x_help_flag
> >=20
> > For this to work, I had to replace the options-save.o with a version
> > compiled by -O0 and that made the problem go away ;-<
>=20
> Or you would have to print &ptr1->x_help_flag with a printf and then
> use gdb for the memory.
>=20
> >=20
> > I am still happy to walk away from this bug report. It is known
> > to occur on only one variant of one architecture and it is hard
> > to reproduce. I can think of better things to work on in gcc.
>=20
> Ok...
>=20
> >=20
> > As far as finding a machine with a bdver2 architecture, I suspect
> > any more recent AMD machine would be fine.=20
> >=20
> > Has no one checked the compile farm ?
>=20
> No, there's not a bdver2 machine.

Maybe the issue reproduces with only -mtune=3Dbdver2 or with -march=3Dbdver=
2=20
-mno-xop (XOP is what's removed from znver2 for example, not 100% sure
that's all, but ...).  It does sound like eventually options-save.c
is miscompiled somehow ...=