From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by sourceware.org (Postfix) with ESMTPS id 33B0D385DC37 for ; Mon, 28 Mar 2022 13:38:53 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 33B0D385DC37 Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-115-l_ew5HXiOViG3cdWQ5PS8g-1; Mon, 28 Mar 2022 09:38:49 -0400 X-MC-Unique: l_ew5HXiOViG3cdWQ5PS8g-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 3BB241C01E94; Mon, 28 Mar 2022 13:38:49 +0000 (UTC) Received: from tucnak.zalov.cz (unknown [10.39.192.15]) by smtp.corp.redhat.com (Postfix) with ESMTPS id F131B2166B25; Mon, 28 Mar 2022 13:38:48 +0000 (UTC) Received: from tucnak.zalov.cz (localhost [127.0.0.1]) by tucnak.zalov.cz (8.16.1/8.16.1) with ESMTPS id 22SDcko93627982 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Mon, 28 Mar 2022 15:38:46 +0200 Received: (from jakub@localhost) by tucnak.zalov.cz (8.16.1/8.16.1/Submit) id 22SDcjSe3627981; Mon, 28 Mar 2022 15:38:45 +0200 Date: Mon, 28 Mar 2022 15:38:45 +0200 From: Jakub Jelinek To: Richard Biener Cc: gcc-patches@gcc.gnu.org, msebor@redhat.com Subject: Re: [PATCH] tree-optimization/105080 - make sure SCEV is available for ranger Message-ID: Reply-To: Jakub Jelinek References: <20220328131625.05BFC13215@imap2.suse-dmz.suse.de> <2orq11q-7817-95q3-2p9r-s3q5958q1r@fhfr.qr> MIME-Version: 1.0 In-Reply-To: <2orq11q-7817-95q3-2p9r-s3q5958q1r@fhfr.qr> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Spam-Status: No, score=-4.4 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, RCVD_IN_DNSWL_LOW, RCVD_IN_MSPIKE_H4, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_NONE, TXREP, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: gcc-patches@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 28 Mar 2022 13:38:54 -0000 On Mon, Mar 28, 2022 at 03:26:11PM +0200, Richard Biener wrote: > On Mon, 28 Mar 2022, Jakub Jelinek wrote: > > > On Mon, Mar 28, 2022 at 03:16:24PM +0200, Richard Biener wrote: > > > When doing format diagnostics at -O0 we should make sure to make > > > SCEV available to avoid false positives due to ranges we otherwise > > > can trivially compute. > > > > > > Bootstrap and regtest running on x86_64-unknown-linux-gnu. > > > > > > OK if that succeeds? > > > > Doesn't this slow down -O0 compilation too much? > > Not if you do not enable the warning. If you enable it you > probably are set to pay for it. Are you specifically > concerned about the cases where SCEV / niter analysis take > a lot of time or are you concerned about the constant overhead > of enabling loops/SCEV? I was just worried about the worst case compile time for -O0. I think we already have tons of -fcompare-debug=-Wall (or -Wextra) dependent code generation (mainly in the C++ FE) so until we are able to deal with it making this -W* dependent isn't the end of the world. Guess the patch is ok. If we find bad compile time issues with it, one way would be to enable it lazily (don't enable it initially, when about to emit first warning instead enable it and retry). Jakub