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 2D244385DC1F; Thu, 20 Jul 2023 12:46:23 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 2D244385DC1F
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1689857183;
	bh=ScArxCyVNv4skh7bUjLDaKLfpWwqD8G3WC6v3vSc8SQ=;
	h=From:To:Subject:Date:In-Reply-To:References:From;
	b=yT/SD/knooGi4m04QwqzGmqPDa18tTt829zQU+vNihyje02jlOp5+BxpMwWhH/4z4
	 mVNPuNuaJBuhHhS2C+My+tPGMQCnBzed3dzaPlM9ySmfNObGWPUtCSUhnV65t3GjXf
	 BzZoKRNb35VhmJISjSUO0C33IHUY0ISex5VGR2Jg=
From: "cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/110204] [14 Regression] Suspicous warning
 when compiling ranges-v3 using GCC trunk (iteration 9223372036854775807
 invokes undefined behavior)
Date: Thu, 20 Jul 2023 12:46:22 +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: 14.0
X-Bugzilla-Keywords: diagnostic, missed-optimization, needs-bisection,
 needs-reduction
X-Bugzilla-Severity: normal
X-Bugzilla-Who: cvs-commit at gcc dot gnu.org
X-Bugzilla-Status: UNCONFIRMED
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P3
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-110204-4-GAKPom4uUj@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-110204-4@http.gcc.gnu.org/bugzilla/>
References: <bug-110204-4@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=3D110204

--- Comment #7 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Richard Biener <rguenth@gcc.gnu.org>:

https://gcc.gnu.org/g:d0de3bf9175877d6c51c94fe04662c6e031876e1

commit r14-2674-gd0de3bf9175877d6c51c94fe04662c6e031876e1
Author: Richard Biener <rguenther@suse.de>
Date:   Mon Jul 17 12:15:29 2023 +0200

    tree-optimization/110204 - second level redundancy and simplification

    When PRE discovers a full redundancy during insertion it cannot unite
    the two value sets.  Instead it inserts a copy old-val =3D new-val where
    new-val can also be a constant.  The following looks through such
    copies during elimination, providing one extra level of constant and
    copy propagation.  For the PR this helps avoiding a bogus diagnostic
    that's emitted on unreachable code during loop optimization.

            PR tree-optimization/110204
            * tree-ssa-sccvn.cc (eliminate_dom_walker::eliminate_avail):
            Look through copies generated by PRE.=