From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 25888 invoked by alias); 7 Jun 2006 20:09:37 -0000 Received: (qmail 25637 invoked by uid 22791); 7 Jun 2006 20:09:25 -0000 X-Spam-Check-By: sourceware.org Received: from intranet.codesourcery.com (HELO mail.codesourcery.com) (65.74.133.6) by sourceware.org (qpsmtpd/0.31) with ESMTP; Wed, 07 Jun 2006 20:08:31 +0000 Received: (qmail 8800 invoked from network); 7 Jun 2006 20:07:45 -0000 Received: from unknown (HELO 85-210-7-2.dsl.pipex.com) (paul@127.0.0.2) by mail.codesourcery.com with ESMTPA; 7 Jun 2006 20:07:45 -0000 From: Paul Brook To: gcc@gcc.gnu.org Subject: Re: [RFC] Optimization Diary Date: Wed, 07 Jun 2006 20:20:00 -0000 User-Agent: KMail/1.9.1 Cc: Devang Patel , tromey@redhat.com References: <44872EC4.70504@gmail.com> In-Reply-To: <44872EC4.70504@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200606072107.44277.paul@codesourcery.com> Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Archive: List-Post: List-Help: Sender: gcc-owner@gcc.gnu.org X-SW-Source: 2006-06/txt/msg00275.txt.bz2 > > I still don't see how gcc maintainers would know to make this > > distinction. Perhaps I'm misunderstanding the distinction between > > command and display. > > for (i=0; i<4; i++) > { > C[i] = A[i] + C[i+3]; > } > > Auto vectorizer emits three messages. > 1) This loop is not vectorized because of data dependency. > 2) Highlight C[i] > 3) Highlight C[i+3] > > Here vectorizer knows that 2) and 3) are commands and 1) is display > message. I don't buy this. Whether things are highlighted or comments added seems like something that the consumer should decide. ie. the compiler generates: 1) {points at for loop} Loop not vectorized because of data dependency 1a) {points at C[i]} Conflicting data element 1b) {points at C[i+3]} Conflicting data element Paul