From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: James Cloos Newsgroups: gmane.emacs.devel Subject: Re: Code for converting between Elisp and Calc floats Date: Thu, 22 Oct 2009 16:04:54 -0400 Message-ID: References: <200910082047.n98KlkAB020482@godzilla.ics.uci.edu> <87aazj2r7d.fsf_-_@vh213601.truman.edu> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: ger.gmane.org 1256242302 32491 80.91.229.12 (22 Oct 2009 20:11:42 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Thu, 22 Oct 2009 20:11:42 +0000 (UTC) Cc: emacs-devel@gnu.org To: jay.p.belanger@gmail.com Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Thu Oct 22 22:11:31 2009 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by lo.gmane.org with esmtp (Exim 4.50) id 1N140Q-0005R9-GT for ged-emacs-devel@m.gmane.org; Thu, 22 Oct 2009 22:11:30 +0200 Original-Received: from localhost ([127.0.0.1]:56490 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1N140P-0002Vb-Sg for ged-emacs-devel@m.gmane.org; Thu, 22 Oct 2009 16:11:29 -0400 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1N13zv-0002F0-1T for emacs-devel@gnu.org; Thu, 22 Oct 2009 16:10:59 -0400 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1N13zp-0002CO-Ui for emacs-devel@gnu.org; Thu, 22 Oct 2009 16:10:58 -0400 Original-Received: from [199.232.76.173] (port=40724 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1N13zp-0002CE-HH for emacs-devel@gnu.org; Thu, 22 Oct 2009 16:10:53 -0400 Original-Received: from eagle.jhcloos.com ([207.210.242.212]:3513) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1N13zp-000269-3i for emacs-devel@gnu.org; Thu, 22 Oct 2009 16:10:53 -0400 Original-Received: by eagle.jhcloos.com (Postfix, from userid 10) id 0099040173; Thu, 22 Oct 2009 20:10:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=jhcloos.com; s=eagle; t=1256242251; bh=NEkeE1sJvqhY+D9dqponFSLVov71s3SSqCRVjDE9C3I=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=B/VimjkVv+zm7xWnoQQZ+5FK4MDWDhcxWeCV7AVQB++RprBUSD8a1SfuoIL7sVK8L gX1CBc5+vx0pqnFDnF1fqhSVvTsl92uGvvVnjSrtp02GhmO9+s3dFAhyWRxngewSMs qxusMtkPF0B+YLjHjhfTgWmWzCgMMq3zhndP+C8Q= Original-Received: by lugabout.jhcloos.org (Postfix, from userid 500) id CBEDB99B4F; Thu, 22 Oct 2009 20:05:18 +0000 (UTC) In-Reply-To: <87aazj2r7d.fsf_-_@vh213601.truman.edu> (Jay Belanger's message of "Thu, 22 Oct 2009 13:56:06 -0500") User-Agent: Gnus/5.110011 (No Gnus v0.11) Emacs/23.1.50 (gnu/linux) Face: iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAYAAAAf8/9hAAAABHNCSVQICAgIfAhkiAAAAI1J REFUOE+lU9ESgCAIg64P1y+ngUdxhl5H8wFbbM0OmUiEhKkCYaZThXCo6KE5sCbA1DDX3genvO4d eBQgEMaM5qy6uWk4SfBYfdu9jvBN9nSVDOKRtwb+I3epboOsOX5pZbJNsBJFvmQQ05YMfieIBnYX FK2N6dOawd97r/e8RjkTLzmMsiVgrAoEugtviCM3v2WzjgAAAABJRU5ErkJggg== Copyright: Copyright 2009 James Cloos OpenPGP: ED7DAEA6; url=http://jhcloos.com/public_key/0xED7DAEA6.asc OpenPGP-Fingerprint: E9E9 F828 61A4 6EA9 0F2B 63E7 997A 9F17 ED7D AEA6 Original-Lines: 29 X-Hashcash: 1:30:091022:jay.p.belanger@gmail.com::IFtMgySvKDSDfX13:0000000000000000000000000000000000007aa2b X-Hashcash: 1:30:091022:emacs-devel@gnu.org::kIImZdDW5nZ1UirO:00000000000000000000000000000000000000000uoTRP X-detected-operating-system: by monty-python.gnu.org: Genre and OS details not recognized. X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:116312 Archived-At: >>>>> "Jay" == Jay Belanger writes: Jay> +--------------------+----------------------------------------+ Jay> |10 |79bit binary IEEE is used by Lisp floats| Jay> +--------------------+----------------------------------------+ Jay> # elif (DBL_MANT_DIG == 1+64 \ Jay> && DBL_MIN_EXP == 1+-16382 \ Jay> && DBL_MAX_EXP == 1+16383) Jay> # define HAVE_DOUBLE_SIZEOF 10 Jay> # elif (DBL_MANT_DIG == 1+112 \ Jay> && DBL_MIN_EXP == 1+-16382 \ Jay> && DBL_MAX_EXP == 1+16383) Jay> # define HAVE_DOUBLE_SIZEOF 16 Jay> # else Jay> # define HAVE_DOUBLE_SIZEOF 0 Jay> # endif As there is no implied bit in the i387's 80-bit float; I suspect that the DBL_MANT_DIG == 1+64 will never match. Also -- and I've no idea whether this is relevant -- the 128 bit long doubles used on IBM's mainframes (and perhaps elsewhere) are the sum of two 64 bit doubles; they have more significant bits, but their exponents are no larger than a double. -JimC -- James Cloos OpenPGP: 1024D/ED7DAEA6