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 41F803858004; Fri, 13 Jan 2023 11:47:41 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 41F803858004
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1673610461;
	bh=Oc1ZBQZze+h/Rmx0NCKFSZBNWgPXkovYYcbajy6a8uE=;
	h=From:To:Subject:Date:In-Reply-To:References:From;
	b=pWTWz0OK3oaTBlWYqtsq3dplILa4AKub6vzAyA/qm09VRWTOT/oJAiX2Gnz6ySpLu
	 aH7Mf+MOoKXOu495jt5oEUgK0jWQSkPjdhbAVEXmp521HjkWPaK/uEbYZnmyyh4AIC
	 kt4C7Mr/RKhRWwT34/pj0DwbZ6m6vdWkfGooZQiY=
From: "rguenth at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/107467] [12/13 Regression] Miscompilation
 involing -Os , -flto and -fno-strict-aliasing since r12-656-ga564da506f52be66
Date: Fri, 13 Jan 2023 11:47:40 +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: 12.2.0
X-Bugzilla-Keywords: lto, wrong-code
X-Bugzilla-Severity: normal
X-Bugzilla-Who: rguenth at gcc dot gnu.org
X-Bugzilla-Status: ASSIGNED
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P2
X-Bugzilla-Assigned-To: hubicka at gcc dot gnu.org
X-Bugzilla-Target-Milestone: 12.3
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: cf_reconfirmed_on priority
Message-ID: <bug-107467-4-AUCxW322fi@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-107467-4@http.gcc.gnu.org/bugzilla/>
References: <bug-107467-4@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=3D107467

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|2022-10-30 00:00:00         |2023-1-13
           Priority|P3                          |P2

--- Comment #8 from Richard Biener <rguenth at gcc dot gnu.org> ---
> diff -u a.ltrans0.ltrans.115t.vrp1 a.ltrans0.ltrans.116t.dse2
...
 __attribute__((noinline, optimize ("strict-aliasing")))
 bool clashy.isra ()
 {
@@ -90,8 +64,6 @@
   bool _1;

   <bb 2> [local count: 1073741824]:
-  D.5191 =3D get_const.isra ();
-  D.5190 =3D get_const.isra ();
   _1 =3D compare_pairs (&D.5190, &D.5191);

so it's ICFed compare_pairs having modref TBAA info that makes the
stores dead.  I suppose ICF needs to reset / alter the modref summaries?=