From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 8196 invoked by alias); 9 Aug 2019 08:14:53 -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 8188 invoked by uid 89); 9 Aug 2019 08:14:52 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-6.3 required=5.0 tests=AWL,BAYES_00,SPF_PASS autolearn=ham version=3.3.1 spammy=H*f:sk:dca38a3, H*i:sk:dca38a3, viz, H*F:U*john X-HELO: jocasta.intra Received: from de.cellform.com (HELO jocasta.intra) (88.217.224.109) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Fri, 09 Aug 2019 08:14:49 +0000 Received: from jocasta.intra (localhost [127.0.0.1]) by jocasta.intra (8.15.2/8.15.2/Debian-8) with ESMTPS id x798EeIH004838 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 9 Aug 2019 10:14:40 +0200 Received: (from john@localhost) by jocasta.intra (8.15.2/8.15.2/Submit) id x798Eerd004837; Fri, 9 Aug 2019 10:14:40 +0200 Date: Fri, 09 Aug 2019 08:14:00 -0000 From: John Darrington To: Jeff Law Cc: Segher Boessenkool , Paul Koning , Vladimir Makarov , John Darrington , gcc@gcc.gnu.org Subject: Re: Indirect memory addresses vs. lra Message-ID: <20190809081439.baoyu3ii5i2qfbzt@jocasta.intra> References: <20190804191822.x4hwnfcyplnto3xc@jocasta.intra> <2B3A4EAB-D69E-4714-8FC4-C25E36B07BFF@comcast.net> <20190808172102.GH31406@gate.crashing.org> <2EEBCFAE-FF25-4664-AA5F-B3299CEA3CB1@comcast.net> <20190808191914.GK31406@gate.crashing.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20170113 (1.7.2) X-IsSubscribed: yes X-SW-Source: 2019-08/txt/msg00067.txt.bz2 On Thu, Aug 08, 2019 at 01:57:41PM -0600, Jeff Law wrote: Yea, it's certainly designed with the more mainstream architectures in mind. THe double-indirect case that's being talked about here is well out of the mainstream and not a feature of anything LRA has targetted to date. So I'm not surprised it's not working. My suggestion would be to ignore the double-indirect aspect of the architecture right now, get the port working, then come back and try to make double-indirect addressing modes work. This sounds like sensible advice. However I wonder if this issue is related to the other major outstanding problem I have, viz: the large number of test failures which report "Unable to find a register to spill" - So far, nobody has been able to explain how to solve that issue and even the people who appear to be more knowlegeable have expressed suprise that it is even happening at all. Even if it should turn out not to be related, the message I've been receiving in this thread is lra should not be expected to work for non "mainstream" backends. So perhaps there is another, yet to be discovered, restriction which prevents my backend from ever working? On the other hand, given my lack of experience with gcc, it could be that lra is working perfectly, and I have simply done something incorrectly. But the uncertainty voiced in this thread means that it is hard to be sure that I'm not trying to do something which is currently unsupported. J' -- Avoid eavesdropping. Send strong encrypted email. PGP Public key ID: 1024D/2DE827B3 fingerprint = 8797 A26D 0854 2EAB 0285 A290 8A67 719C 2DE8 27B3 See http://sks-keyservers.net or any PGP keyserver for public key.