From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id A78DE3858401; Mon, 26 Jun 2023 08:22:12 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org A78DE3858401 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1687767732; bh=cWW7+1+ynklmeCWw4B+JRyo+hMEVaFu5ZfGMwvoBghI=; h=From:To:Subject:Date:In-Reply-To:References:From; b=QlX5K+pvN0YtyqERbhFL0W1g6i/ABhu9Ht1YSmO45Y6QOW+l1DdNIW2Bn3ntoiQ6F JfWefqb+zZkS9q0WFGfBiwW+v00Uki0t8TgxokbihbBRKsLCIt+foaNMWc97II0ugA n3QCOxaQcLzL3eXf8QXpmQE1IEHQqT+bKyrl84GU= From: "amonakov at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug rtl-optimization/110237] gcc.dg/torture/pr58955-2.c is miscompiled by RTL scheduling after reload Date: Mon, 26 Jun 2023 08:22:11 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: rtl-optimization X-Bugzilla-Version: 14.0 X-Bugzilla-Keywords: wrong-code X-Bugzilla-Severity: normal X-Bugzilla-Who: amonakov 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: In-Reply-To: References: 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: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D110237 --- Comment #13 from Alexander Monakov --- (In reply to rguenther@suse.de from comment #12) > As explained in comment#3 the issue is related to the tree alias oracle > part that gets invoked on the MEM_EXPR for the load where there is > no information that the load could be partial so it gets disambiguated > against a decl that's off less size than the full vector. With my example I'm trying to say that types in the IR are wrong if we disambiguate like that. People writing C need to attach may_alias to vector types for plain load/stores to validly overlap with scalar accesses, and wh= en vectorizer introduces vector accesses it needs to do something like that, or else intermixed scalar accesses may be incorrectly disambiguated against new vector ones.=