From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 1947 invoked by alias); 11 Feb 2020 18:12:21 -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 1938 invoked by uid 89); 11 Feb 2020 18:12:21 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-2.3 required=5.0 tests=AWL,BAYES_00,KAM_SHORT,RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 spammy= 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; Tue, 11 Feb 2020 18:12:20 +0000 Received: from gate.crashing.org (localhost.localdomain [127.0.0.1]) by gate.crashing.org (8.14.1/8.14.1) with ESMTP id 01BICHN8010599; Tue, 11 Feb 2020 12:12:17 -0600 Received: (from segher@localhost) by gate.crashing.org (8.14.1/8.14.1/Submit) id 01BICG6k010598; Tue, 11 Feb 2020 12:12:16 -0600 Date: Tue, 11 Feb 2020 18:12:00 -0000 From: Segher Boessenkool To: Roman Zhuykov Cc: Richard Biener , "Kewen.Lin" , GCC Patches , Bill Schmidt , "bin.cheng" Subject: Re: [PATCH 0/4 GCC11] IVOPTs consider step cost for different forms when unrolling Message-ID: <20200211181216.GX22482@gate.crashing.org> References: <20200120123332.GV3191@gate.crashing.org> <52c8eecc-3383-81ad-70ce-27c149d7a103@linux.ibm.com> <20200210212910.GL22482@gate.crashing.org> <20200211074859.GV22482@gate.crashing.org> <1ac98132-734e-0ee3-5ea2-7ec256ee92d2@ispras.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1ac98132-734e-0ee3-5ea2-7ec256ee92d2@ispras.ru> User-Agent: Mutt/1.4.2.3i X-IsSubscribed: yes X-SW-Source: 2020-02/txt/msg00666.txt.bz2 Hi! On Tue, Feb 11, 2020 at 03:46:05PM +0300, Roman Zhuykov wrote: > Hmm, even when trying to move it just few passes earlier many years ago, > got another opinion: > https://gcc.gnu.org/ml/gcc-patches/2011-10/msg01526.html > Although without such a move we still have annoying issues which RTL > folks can't solve, see e.q. > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93264#c2 Basic block partitioning has wildly disproportionate fallout in all later passes, both in terms of what those *do* (or don't, if partitioning is enabled), and of impact on the code (not to mention developer time). Maybe the implementation can be improved, but probably we should do this in a different way altogether. The current situation is not good. Segher