From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 46343 invoked by alias); 24 Nov 2016 16:14:31 -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 46328 invoked by uid 89); 24 Nov 2016 16:14:31 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-4.7 required=5.0 tests=AWL,BAYES_00,RP_MATCHES_RCVD autolearn=ham version=3.3.2 spammy=quality, H*r:8.13.8 X-HELO: gate.crashing.org Received: from gate.crashing.org (HELO gate.crashing.org) (63.228.1.57) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Thu, 24 Nov 2016 16:14:30 +0000 Received: from gate.crashing.org (localhost.localdomain [127.0.0.1]) by gate.crashing.org (8.14.1/8.13.8) with ESMTP id uAOGEPfE004875; Thu, 24 Nov 2016 10:14:26 -0600 Received: (from segher@localhost) by gate.crashing.org (8.14.1/8.14.1/Submit) id uAOGEOmD004874; Thu, 24 Nov 2016 10:14:24 -0600 Date: Thu, 24 Nov 2016 16:14:00 -0000 From: Segher Boessenkool To: Jeff Law Cc: Bernd Schmidt , GCC Patches Subject: Re: [0/3] Fix PR78120, in ifcvt/rtlanal/i386. Message-ID: <20161124161423.GG14394@gate.crashing.org> References: <2bde94e0-b470-8aad-6a9c-91e45dc8b687@redhat.com> <20161124142119.GD14394@gate.crashing.org> <165a4b5a-86f3-4b0c-a2fe-dd5a40ef4f08@redhat.com> <20161124143632.GE14394@gate.crashing.org> <1cd79d19-c745-c3e6-10ca-a53709e35e09@redhat.com> <20161124145354.GF14394@gate.crashing.org> <3fbcaeeb-7855-82c8-8380-de893c08735e@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3fbcaeeb-7855-82c8-8380-de893c08735e@redhat.com> User-Agent: Mutt/1.4.2.3i X-IsSubscribed: yes X-SW-Source: 2016-11/txt/msg02570.txt.bz2 On Thu, Nov 24, 2016 at 08:48:04AM -0700, Jeff Law wrote: > On 11/24/2016 07:53 AM, Segher Boessenkool wrote: > > > >That we compare different kinds of costs (which really has no meaning at > >all, it's a heuristic at best) in various places is a known problem, not > >a regression. > But the problems with the costing system exhibit themselves as a code > quality regression. In the end that's what the end-users see -- a > regression in the quality of the code GCC generates. Yes, exactly -- and I fear this all-encompassing change will cause just such a regression for many users. Tests are running, will know more later today (or tomorrow). The PR is about a very specific problem; the patch is not. The patch is not a bug fix. If we allow anything that "makes things better" in stage 3, what make it different from stage 1 then? Segher