From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 1977 invoked by alias); 14 Jan 2012 10:22:30 -0000 Received: (qmail 1967 invoked by uid 22791); 14 Jan 2012 10:22:29 -0000 X-SWARE-Spam-Status: No, hits=-1.1 required=5.0 tests=AWL,BAYES_00 X-Spam-Check-By: sourceware.org Received: from tetra.codeconfidence.com (HELO tetra.codeconfidence.com) (94.229.66.225) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Sat, 14 Jan 2012 10:22:08 +0000 Received: from cog.dallaway.org.uk (cpc1-cmbg10-0-0-cust34.5-4.cable.virginmedia.com [81.102.132.35]) by tetra.codeconfidence.com (Postfix) with ESMTP id 967CC234C179; Sat, 14 Jan 2012 10:22:06 +0000 (GMT) Received: from cog.dallaway.org.uk (cog.dallaway.org.uk [127.0.0.1]) by cog.dallaway.org.uk (8.13.8/8.13.8) with ESMTP id q0EAM5TB019187; Sat, 14 Jan 2012 10:22:06 GMT Message-ID: <4F11574D.9070002@dallaway.org.uk> Date: Sat, 14 Jan 2012 10:22:00 -0000 From: John Dallaway User-Agent: Thunderbird 2.0.0.24 (X11/20111109) MIME-Version: 1.0 To: Ilija Kocho CC: eCos developers Subject: Re: Gnutools: consideration for upgrade to GCC 4.6 References: <4F106345.4080902@siva.com.mk> In-Reply-To: <4F106345.4080902@siva.com.mk> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Mailing-List: contact ecos-devel-help@ecos.sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: ecos-devel-owner@ecos.sourceware.org X-SW-Source: 2012-01/txt/msg00008.txt.bz2 Hi Ilija and all Ilija Kocho wrote: > Our GCC 4.3.2 is ageing and perhaps we should consider an upgrade. > My motive is it's lacking of support for Cortex-M4 SIMD (aka DSP) and > FPU instructions, but I think that other architectures shall gain from > newer compiler too. I have made some signal processing tests with GCC > 4.6.2 against current eCos compiler and they show performance gain even > with Cortex-M3 setting, though moderate. Performance is considerable > when Cortex-M4 setting is selected and is tremendous, as expected, when > SIMD are used. Recently introduced Cortex-M products with FPU (Kinetis > K70, K61, STM32F4) will further emphasise the benefit. > > Another reason, maybe not so important, is that GCC 4.3 is not > officially supported any more. > > Regarding this, I state my wish that we move to the latest stable GCC > release, that is at present rel. 4.6.2, accompanied with respective > binutils. I have tested binutils 2.21 but in meantime 2.22 has been > released. Of course, the list wouldn't be complete without the latest GDB. Moving to a more recent GCC makes sense to me. There are sure to be some new compiler warnings to deal with in the eCos sources. Are you aware of the scale of this issue with eCos CVS and GCC 4.6.2? There are a few patches that were applied to current toolchain sources: ftp://ecos.sourceware.org/pub/ecos/gnutools/src/ It would be useful to review these and determine which are still relevant. Certainly we would need to adjust the multi-libbing for some target architectures. It would also be useful to test eCos with the new toolchain in an automated manner. I wonder if one of the maintainers at eCosCentric could set up testing in their test farm? In any case, I would advocate a cautious approach to roll out, creating an initial "test release" for use mostly by those interested in the new features. We could also consider building the toolchain for arm-eabi targets only in the first instance to reduce overall effort. Does anyone on this list have a particular interest in building eCos with recent GCC for another target architecture? It would be important to retain eCos source compatibility with the current toolchains based on GCC 4.3.2. John Dallaway eCos maintainer http://www.dallaway.org.uk/john