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 28DDF3870878; Mon, 14 Sep 2020 13:22:19 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 28DDF3870878
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
 s=default; t=1600089739;
 bh=+Wwj1YPJbdyhXiwmC7QI71uL0C+fWYbCd6BYfSg+oSM=;
 h=From:To:Subject:Date:In-Reply-To:References:From;
 b=VNbXrnylDHygrmmHBZQeAgpzuQmKRaEdZYDrkzUc61WOah60q2iA1nn7we2xDzpBn
 t3rW3MRkbuaGI08lr95EPVgzu0pAdmmn6+d1Twau+D+1Pui7IoKQafGeR4r4a8cyRw
 p9PRPP3NrGIZFcBdYi2iZr4doGuD3ggs6LoXxzuA=
From: "cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/97043] latent wrong-code with SLP vectorization
Date: Mon, 14 Sep 2020 13:22:19 +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: 10.2.1
X-Bugzilla-Keywords: wrong-code
X-Bugzilla-Severity: normal
X-Bugzilla-Who: cvs-commit at gcc dot gnu.org
X-Bugzilla-Status: ASSIGNED
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: rguenth at gcc dot gnu.org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: 
Message-ID: <bug-97043-4-NKAjrgEqaF@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-97043-4@http.gcc.gnu.org/bugzilla/>
References: <bug-97043-4@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, 14 Sep 2020 13:22:19 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D97043

--- Comment #2 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-10 branch has been updated by Richard Biener
<rguenth@gcc.gnu.org>:

https://gcc.gnu.org/g:e93428a8b056aed83a7678d4dc8272131ab671ba

commit r10-8759-ge93428a8b056aed83a7678d4dc8272131ab671ba
Author: Richard Biener <rguenther@suse.de>
Date:   Mon Sep 14 11:25:04 2020 +0200

    tree-optimization/97043 - fix latent wrong-code with SLP vectorization

    When the unrolling decision comes late and would have prevented
    eliding a SLP load permutation we can end up generating aligned
    loads when the load is in fact unaligned.  Most of the time
    alignment analysis figures out the load is in fact unaligned
    but that cannot be relied upon.

    The following removes the SLP load permutation eliding based on
    the still premature vectorization factor.

    2020-09-14  Richard Biener  <rguenther@suse.de>

            PR tree-optimization/97043
            * tree-vect-slp.c (vect_analyze_slp_instance): Do not
            elide a load permutation if the current vectorization
            factor is one.=