From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Paul Eggert Newsgroups: gmane.emacs.devel Subject: Re: Objects layout and tagging scheme Date: Thu, 02 Aug 2012 11:09:21 -0700 Organization: UCLA Computer Science Department Message-ID: <501AC251.8070203@cs.ucla.edu> References: <501AA66C.2030507@yandex.ru> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Trace: dough.gmane.org 1343930970 3052 80.91.229.3 (2 Aug 2012 18:09:30 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Thu, 2 Aug 2012 18:09:30 +0000 (UTC) To: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Thu Aug 02 20:09:30 2012 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1Swzpy-0002LV-66 for ged-emacs-devel@m.gmane.org; Thu, 02 Aug 2012 20:09:30 +0200 Original-Received: from localhost ([::1]:56204 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Swzpx-00057j-7b for ged-emacs-devel@m.gmane.org; Thu, 02 Aug 2012 14:09:29 -0400 Original-Received: from eggs.gnu.org ([208.118.235.92]:38838) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Swzpt-00057T-Vz for emacs-devel@gnu.org; Thu, 02 Aug 2012 14:09:26 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Swzpq-0000DR-0Y for emacs-devel@gnu.org; Thu, 02 Aug 2012 14:09:25 -0400 Original-Received: from smtp.cs.ucla.edu ([131.179.128.62]:45629) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Swzpp-0000DL-QX for emacs-devel@gnu.org; Thu, 02 Aug 2012 14:09:21 -0400 Original-Received: from localhost (localhost.localdomain [127.0.0.1]) by smtp.cs.ucla.edu (Postfix) with ESMTP id 7700E39E8014 for ; Thu, 2 Aug 2012 11:09:21 -0700 (PDT) X-Virus-Scanned: amavisd-new at smtp.cs.ucla.edu Original-Received: from smtp.cs.ucla.edu ([127.0.0.1]) by localhost (smtp.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id DMZ-PbWdU1RE for ; Thu, 2 Aug 2012 11:09:21 -0700 (PDT) Original-Received: from [192.168.1.4] (pool-108-23-119-2.lsanca.fios.verizon.net [108.23.119.2]) by smtp.cs.ucla.edu (Postfix) with ESMTPSA id 102A539E8013 for ; Thu, 2 Aug 2012 11:09:21 -0700 (PDT) User-Agent: Mozilla/5.0 (X11; Linux i686; rv:14.0) Gecko/20120714 Thunderbird/14.0 In-Reply-To: <501AA66C.2030507@yandex.ru> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 3) X-Received-From: 131.179.128.62 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:152127 Archived-At: On 08/02/2012 09:10 AM, Dmitry Antipov wrote: > vectors and string are affected. So I would like to raise the following > question: if I need, for example, 2 extra bits for each object, where to get them? For strings, 3 bits are free in the pointers to intervals, if we can assume intervals are aligned like other lisp objects, which should be possible to arrange. For vectors the same trick could be played, with next.buffer and next.vector. Presumably we can think of a similar way to do it with next.nbytes, since nbytes is limited.