From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 3898 invoked by alias); 25 Jul 2011 17:44:51 -0000 Received: (qmail 3886 invoked by uid 22791); 25 Jul 2011 17:44:50 -0000 X-SWARE-Spam-Status: No, hits=-2.5 required=5.0 tests=AWL,BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,RCVD_IN_DNSWL_LOW,TW_FD X-Spam-Check-By: sourceware.org Received: from mail-fx0-f51.google.com (HELO mail-fx0-f51.google.com) (209.85.161.51) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Mon, 25 Jul 2011 17:44:35 +0000 Received: by fxh10 with SMTP id 10so9540687fxh.10 for ; Mon, 25 Jul 2011 10:44:33 -0700 (PDT) Received: by 10.223.159.2 with SMTP id h2mr7160156fax.5.1311615873813; Mon, 25 Jul 2011 10:44:33 -0700 (PDT) Received: from sg-laptop ([178.123.134.191]) by mx.google.com with ESMTPS id q1sm1421502faa.3.2011.07.25.10.44.29 (version=TLSv1/SSLv3 cipher=OTHER); Mon, 25 Jul 2011 10:44:30 -0700 (PDT) Date: Mon, 25 Jul 2011 17:44:00 -0000 From: Sergei Gavrikov To: Ilija Kocho cc: eCos developers Subject: Re: Single precision math library, porting to eCos. In-Reply-To: <4E253131.3030607@siva.com.mk> Message-ID: References: <4E253131.3030607@siva.com.mk> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-IsSubscribed: yes 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: 2011-07/txt/msg00005.txt.bz2 On Tue, 19 Jul 2011, Ilija Kocho wrote: > Hello colleagues Hello Ilija, my $0.02. > We are working on a port of Newlib's single precision math library > /float/ type functions/. We are going to contribute the port, so we > would like to know if there is interest to incorporate it into main > eCos tree. It's very excited and honour task. But, AFAIK, eCos libm are based on Free Domain Libm fdlibm 5.X (5.2?). The *fdlibm* is a part of netlib software collection, the references: http://www.netlib.org/ http://www.netlib.org/fdlibm/ and it (fdlibm) is labeled as C math library for machines that support IEEE 754 floating-point > Rartionale: Some recent/upcoming architectures such as Cortex-M4, > Cortex-R, MPC 55xx can execute single precision floating point in > hardware. This is also recognised by GCC, for instance GCC 4.6 can > generate /-mhard-float/ code for Cortex-M4. Good point. But, may be first you would look on *Cephes Mathematical Library* http://www.netlib.org/cephes/singldoc.html It would be nice to get a set of single precision special math functions like logf(), sinf(), cosf(), etc. as eCos math alternative which cephes provides us. But, this is my brief view only. It seemed for me that to get *cephes* under eCos is less complex task than to port the same part from NewLib (may be I wrong, I have not dived in the subject). In any case I like your idea to use hardware for single precision calculations and value your efforts in this direction. Sergei > Regards > > Ilija Kocho, manager > SIvA doo > http://www.siva.mk >