From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 13824 invoked by alias); 6 Apr 2011 19:33:32 -0000 Received: (qmail 13814 invoked by uid 22791); 6 Apr 2011 19:33:31 -0000 X-SWARE-Spam-Status: No, hits=-6.9 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_HI,SPF_HELO_PASS,T_RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Wed, 06 Apr 2011 19:33:22 +0000 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id p36JX9M2027891 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Wed, 6 Apr 2011 15:33:09 -0400 Received: from ns3.rdu.redhat.com (ns3.rdu.redhat.com [10.11.255.199]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id p36JX8X5017662; Wed, 6 Apr 2011 15:33:09 -0400 Received: from [10.3.113.84] (ovpn-113-84.phx2.redhat.com [10.3.113.84]) by ns3.rdu.redhat.com (8.13.8/8.13.8) with ESMTP id p36JX7qb005819; Wed, 6 Apr 2011 15:33:07 -0400 Message-ID: <4D9CBFF2.4050400@redhat.com> Date: Wed, 06 Apr 2011 19:33:00 -0000 From: Jeff Law User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.15) Gecko/20110307 Fedora/3.1.9-0.39.b3pre.fc14 Lightning/1.0b3pre Thunderbird/3.1.9 MIME-Version: 1.0 To: Steven Bosscher CC: Eric Botcazou , gcc-patches@gcc.gnu.org Subject: Re: [RFC] Remove kludge in commit_edge_insertions References: <201104042307.56517.ebotcazou@adacore.com> <4D9C9A58.6050205@redhat.com> <4D9CADDC.5080909@redhat.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-IsSubscribed: yes 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 X-SW-Source: 2011-04/txt/msg00509.txt.bz2 -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 04/06/11 12:39, Steven Bosscher wrote: > On Wed, Apr 6, 2011 at 8:37 PM, Steven Bosscher wrote: >> On Wed, Apr 6, 2011 at 8:15 PM, Jeff Law wrote: >> >>>> AFAIU the patch doesn't change behavior for the GIMPLE CFG. It only affects RTL. >>> But the elimination of the PHI results in creating RTL that is inserted >>> on a CFG edge. >> >> Yes, but gimple_expand_cfg() calls find_many_sub_basic_blocks(), and >> that should be enough, no?? >> >> /me goes back to trying to understand this code :-) > > Could you please add an explanation to the PR about how that PHI > results in a loop on an edge? My fantasy is not big enough to > visualize any case where that can happen! Presumably it's the vector initialization. THere's a fair amount of backend goop that comes into play. Peek at expand_set_or_movmem_via_loop. jeff -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) Comment: Using GnuPG with Fedora - http://enigmail.mozdev.org/ iQEcBAEBAgAGBQJNnL/yAAoJEBRtltQi2kC7LfoH/jWh+8b77bjuLQnVyBrB8Naj UWOPmPQHzs6DT1THXz8ef+pS3Bvuhbm+RxnHWhUTJQ9qBYwCf2oXzZDgytadfGo7 PKEtRpJTe4z7dwTGvp6UUX16TEI29OLHeNyyiDdEQ2ryCHJaSYB1MC8PEANilaHW uYAvTOkLbk6ORjx06pleVGy0IJW1UwLeQoJ2ggZvvmPZz8NghAWuvdfVkoX409wo vjOJ/EnDI603zKazh8yLI0c1K+jZNjnqqlxM8kC3GSt1lJt0LSO5vKW47H0E4zf0 rXhfj5WTiNJ0b0QjGGreIbKjUT8HLPjTJe3gurqgS25R2NtWCv9zxkYFu7sCGPo= =2tG9 -----END PGP SIGNATURE-----