From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 7376 invoked by alias); 8 Aug 2019 17:21:38 -0000 Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-owner@gcc.gnu.org Received: (qmail 7363 invoked by uid 89); 8 Aug 2019 17:21:38 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-2.2 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 spammy=H*f:sk:2B3A4EA, H*Ad:D*au, H*i:sk:2B3A4EA, peepholes 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, 08 Aug 2019 17:21:37 +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 x78HL4uE014657; Thu, 8 Aug 2019 12:21:04 -0500 Received: (from segher@localhost) by gate.crashing.org (8.14.1/8.14.1/Submit) id x78HL31I014656; Thu, 8 Aug 2019 12:21:03 -0500 Date: Thu, 08 Aug 2019 17:21:00 -0000 From: Segher Boessenkool To: Paul Koning Cc: Vladimir Makarov , John Darrington , gcc@gcc.gnu.org Subject: Re: Indirect memory addresses vs. lra Message-ID: <20190808172102.GH31406@gate.crashing.org> References: <20190804191822.x4hwnfcyplnto3xc@jocasta.intra> <2B3A4EAB-D69E-4714-8FC4-C25E36B07BFF@comcast.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2B3A4EAB-D69E-4714-8FC4-C25E36B07BFF@comcast.net> User-Agent: Mutt/1.4.2.3i X-IsSubscribed: yes X-SW-Source: 2019-08/txt/msg00045.txt.bz2 On Thu, Aug 08, 2019 at 12:43:52PM -0400, Paul Koning wrote: > > On Aug 8, 2019, at 12:25 PM, Vladimir Makarov wrote: > > The old reload (reload[1].c) supports such addressing. As modern mainstream architectures have no this kind of addressing, it was not implemented in LRA. > > Is LRA only intended for "modern mainstream architectures"? I sure hope not! But it has only been *used* and *tested* much on such, so far. Things are designed to work well for modern archs. > If yes, why is the old reload being deprecated? You can't have it both ways. Unless you want to obsolete all "not modern mainstream architectures" in GCC, it doesn't make sense to get rid of core functionality used by those architectures. > > Indirect addressing is a key feature in size-optimized code. That doesn't mean that LRA has to support it, btw, not necessarily; it may well be possible to do a good job of this in the later passes? Maybe postreload, maybe some peepholes, etc.? Segher