From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 9821 invoked by alias); 19 Jul 2016 14:49:31 -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 8084 invoked by uid 89); 19 Jul 2016 14:49:30 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-3.2 required=5.0 tests=BAYES_00,RP_MATCHES_RCVD,SPF_HELO_PASS autolearn=ham version=3.3.2 spammy=Hx-languages-length:545, perfectly X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES256-GCM-SHA384 encrypted) ESMTPS; Tue, 19 Jul 2016 14:49:29 +0000 Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id DE997F263D; Tue, 19 Jul 2016 14:49:27 +0000 (UTC) Received: from localhost.localdomain (vpn1-4-21.ams2.redhat.com [10.36.4.21]) by int-mx13.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u6JEnQI2029679; Tue, 19 Jul 2016 10:49:27 -0400 Subject: Re: [PATCH 8/9] shrink-wrap: shrink-wrapping for separate concerns To: Segher Boessenkool References: <019d5b4c3f6b8119e1511e33a16a8ea96078b094.1465347472.git.segher@kernel.crashing.org> <20160718163411.GA5741@gate.crashing.org> <20160719144602.GA26941@gate.crashing.org> Cc: gcc-patches@gcc.gnu.org, dje.gcc@gmail.com From: Bernd Schmidt Message-ID: Date: Tue, 19 Jul 2016 14:49:00 -0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.0 MIME-Version: 1.0 In-Reply-To: <20160719144602.GA26941@gate.crashing.org> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-IsSubscribed: yes X-SW-Source: 2016-07/txt/msg01149.txt.bz2 On 07/19/2016 04:46 PM, Segher Boessenkool wrote: > But you need the profile to make even reasonably good decisions. I'm not worried about making cost decisions: as far as I'm concerned it's perfectly fine for that. I'm worried about correctness - you can't validly save registers inside a loop. So IMO there needs to be an additional cfg-based check that verifies whether the bb where we want to place parts of the prologue is guaranteed to be executed at most once. Bernd