From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 22835 invoked by alias); 21 Aug 2015 09:29:31 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Received: (qmail 22819 invoked by uid 89); 21 Aug 2015 09:29:30 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.7 required=5.0 tests=AWL,BAYES_00,SPF_PASS autolearn=ham version=3.3.2 X-HELO: eu-smtp-delivery-143.mimecast.com Received: from eu-smtp-delivery-143.mimecast.com (HELO eu-smtp-delivery-143.mimecast.com) (146.101.78.143) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Fri, 21 Aug 2015 09:29:29 +0000 Received: from cam-owa1.Emea.Arm.com (fw-tnat.cambridge.arm.com [217.140.96.140]) by eu-smtp-1.mimecast.com with ESMTP id uk-mta-15-XdvfqaL6STCIeBVFY3OlLg-1; Fri, 21 Aug 2015 10:29:25 +0100 Received: from e104437-lin ([10.1.2.79]) by cam-owa1.Emea.Arm.com with Microsoft SMTPSVC(6.0.3790.3959); Fri, 21 Aug 2015 10:29:24 +0100 References: From: Jiong Wang To: Richard Biener Cc: "gcc-patches\@gcc.gnu.org" Subject: Re: [PATCH] Fix PRs 66502 and 67167 Date: Fri, 21 Aug 2015 09:45:00 -0000 In-reply-to: Message-ID: MIME-Version: 1.0 X-MC-Unique: XdvfqaL6STCIeBVFY3OlLg-1 Content-Type: text/plain; charset=WINDOWS-1252 Content-Transfer-Encoding: quoted-printable X-SW-Source: 2015-08/txt/msg01288.txt.bz2 Richard Biener writes: > Given there is now PR67167 I am going forward with the earlier posted > patch to switch SCCVN to PHI elimination in favor of another PHI > (to remove IVs) rather than in favor of its only executable edge value. > > I still see no way to capture both cases without detecting the choice > and re-numbering the SCC twice, eventually choosing the "better" outcome. > And then the situation where both cases happen in the same SCC is not > handled either. > > Bootstrapped and tested on x86_64-unknown-linux-gnu, applied to trunk. > > Richard. > > 2015-08-13 Richard Biener > > PR tree-optimization/66502 > PR tree-optimization/67167 > * tree-ssa-sccvn.c (vn_phi_compute_hash): Do not include > backedge arguments. > (vn_phi_lookup): Adjust. > (vn_phi_insert): Likewise. > (visit_phi): Prefer to value-number to another PHI node > over value-numbering to a PHI argument. > (init_scc_vn): Mark DFS back edges. Richard, I suspect this patch r226850 caused internal compiler error on ./gcc/testsuite/gcc.c-torture/compile/20121027-1.c on arm-non-eabi. The ICE gone away if I revert this patch. it can be easily reproduced by the following command. -mfpu and -mfloat are necessary. =20=20 ./cc1 -O3 -nostdinc 20121027-1.c -march=3Darmv8-a -mthumb -mfpu=3Dcrypto-neon-fp-armv8 -mfloat-abi=3Dhard cc1 is generated from =20=20 ../gcc/configure --target=3Darm-none-eabi --enable-languages=3Dc,c++ do you mind to have a look? Thanks. --=20 Regards, Jiong