From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 17921 invoked by alias); 19 Jan 2003 18:53:56 -0000 Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Archive: List-Post: List-Help: Sender: gcc-owner@gcc.gnu.org Received: (qmail 17856 invoked from network); 19 Jan 2003 18:53:55 -0000 Received: from unknown (HELO monty-python.gnu.org) (199.232.76.173) by 172.16.49.205 with SMTP; 19 Jan 2003 18:53:55 -0000 Received: from nat-pool-rdu.redhat.com ([66.187.233.200] helo=lacrosse.corp.redhat.com) by monty-python.gnu.org with esmtp (Exim 4.10.13) id 18aKZd-0003xo-00; Sun, 19 Jan 2003 13:53:37 -0500 Received: from free.redhat.lsd.ic.unicamp.br (aoliva.cipe.redhat.com [10.0.1.10]) by lacrosse.corp.redhat.com (8.11.6/8.9.3) with ESMTP id h0JIqNg06964; Sun, 19 Jan 2003 13:52:24 -0500 Received: from free.redhat.lsd.ic.unicamp.br (localhost.localdomain [127.0.0.1]) by free.redhat.lsd.ic.unicamp.br (8.12.6/8.12.6) with ESMTP id h0JIqTj7027588; Sun, 19 Jan 2003 16:52:29 -0200 Received: (from aoliva@localhost) by free.redhat.lsd.ic.unicamp.br (8.12.6/8.12.6/Submit) id h0JIqS9o027584; Sun, 19 Jan 2003 16:52:28 -0200 To: "Kaveh R. Ghazi" Cc: gcc-bugs@gcc.gnu.org, gcc-patches@gcc.gnu.org, gcc@gcc.gnu.org, libstdc++@gcc.gnu.org, oldham@codesourcery.com, ro@TechFak.Uni-Bielefeld.DE, rth@redhat.com Subject: Re: Irix6 long doubles implemented wrong? (27_io/ostream_inserter_arith) References: <200212170531.AAA15561@caip.rutgers.edu> <200212241434.JAA22361@caip.rutgers.edu> <20030107221549.GR12992@redhat.com> <20030110011352.GF9245@redhat.com> <200301191731.MAA18215@caip.rutgers.edu> From: Alexandre Oliva Organization: GCC Team, Red Hat Date: Sun, 19 Jan 2003 22:15:00 -0000 In-Reply-To: <200301191731.MAA18215@caip.rutgers.edu> Message-ID: User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.2 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-SW-Source: 2003-01/txt/msg00907.txt.bz2 On Jan 19, 2003, "Kaveh R. Ghazi" wrote: > So, what happened to the irix6 long double patch? It will require some changes, after all. As per my reading of LIA (this morning, talk about coincidence :-), the minimum normal exponent should be set such that all 107 significant bits are available (and it's 107, not 106, as I implemented it) for normals. This means we'll consider denormals even numbers that have only the lower double as a denormal. Which is in line with one of the approaches I had suggested (not that it counts much; I've probably enumerated all approaches that could possibly make sense, and most that couldn't :-D This conclusion was drawn based on the formal definition of the normalized and denormalized sets, as well as the informal definitions of normalized (those values of a floating point type F that provide the full precision allowed by that type) and denormalized (those that don't), regardless of the actual representation. I believe this settles it. Now it just needs someone to implement these changes. Unfortunately, the mips64-linux-gnu port I'd been working on, that looked like would need IRIX compatibility in terms of floating point format, ended up with a different format, so I no longer have a good reason to put work time into finishing the patch. I've been trying to find spare time to do it in a voluntary basis, but spare time is approaching non-existence from the negative range :-) Anyway, if I had the time, I'd start by adding 53 to the minimum exponent range in real.c and fp-bit.h, bumping up the mantissa size by 1 and reverting the denorm_p changes I made in real.c and c-common.c. This would probably require some tweaks in the functions that convert into and out of ibm_extended_format in real.c, such that the change in the minimum exponent doesn't change the representation of any numbers, and probably some similar fixes in fp-bit.c, for the same reason. Would you like to give it a try? Or would you rather my cobble up some day a new version of the patch for you to try? Please let me know. -- Alexandre Oliva Enjoy Guarana', see http://www.ic.unicamp.br/~oliva/ Red Hat GCC Developer aoliva@{redhat.com, gcc.gnu.org} CS PhD student at IC-Unicamp oliva@{lsd.ic.unicamp.br, gnu.org} Free Software Evangelist Professional serial bug killer