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 E3ADD3858D35; Sun, 19 Nov 2023 09:42:49 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org E3ADD3858D35
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1700386969;
	bh=nWF5j3folzAXycudNnfF7i6aPbsTdf+G2C1tQ7lfGEE=;
	h=From:To:Subject:Date:In-Reply-To:References:From;
	b=BjGARlqv/TDuqn7rpAd2ii3Lr9xHO6M661eX0uHyJYGiXq7v52TjyscgRPYkS5PsW
	 796OnK7McxwTiOHfcy8oyHxeeJNN757zASUgZ+iaO6329MQBmq+wbxda1f3+BaUWMW
	 SGyweerY+x0Xhzb/BOUSOHeFw1ydnBhWFVQ0o0RE=
From: "sjames at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug middle-end/112572] [14 regression] LLVM miscompiled since
 r14-5355-g3cd3a09b3f91a1
Date: Sun, 19 Nov 2023 09:42:48 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: middle-end
X-Bugzilla-Version: 14.0
X-Bugzilla-Keywords: wrong-code
X-Bugzilla-Severity: blocker
X-Bugzilla-Who: sjames at gcc dot gnu.org
X-Bugzilla-Status: NEW
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P1
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: 14.0
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: 
Message-ID: <bug-112572-4-Qk1JUcKh7e@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-112572-4@http.gcc.gnu.org/bugzilla/>
References: <bug-112572-4@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
List-Id: <gcc-bugs.sourceware.org>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D112572

--- Comment #27 from Sam James <sjames at gcc dot gnu.org> ---
(In reply to Andrew Pinski from comment #18)
> This fixes the issue for me:
> ```
> diff --git a/gcc/compare-elim.cc b/gcc/compare-elim.cc
> [...]

This solves both pipewire (unreported, was working on reducing it; found it
needed -fstack-protector-strong and I think PIE) and LLVM failures. Thank y=
ou
Andrew & thanks Sergei for looking at it too.

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D112613#c3 is an interesting
comment wrt checking. Is that feasible?

It would be nice if this was catchable with --enable-checking=3Drtl or
--enable-checking=3Ddf (I don't test with this regularly, but it would've b=
een
helpful after seeing the bisect result), especially given there's some clear
(possible) misuse.=