From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Dmitry Antipov Newsgroups: gmane.emacs.devel Subject: Re: [RFC, PATCH] shrink struct vectorlike_header #2 Date: Thu, 08 Nov 2012 17:31:11 +0400 Message-ID: <509BB41F.6080108@yandex.ru> References: <50766A2C.8070705@yandex.ru> <50994448.6020602@yandex.ru> <509A76F7.3050105@yandex.ru> <509B4246.2050203@cs.ucla.edu> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Trace: ger.gmane.org 1352381471 32321 80.91.229.3 (8 Nov 2012 13:31:11 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Thu, 8 Nov 2012 13:31:11 +0000 (UTC) Cc: Stefan Monnier , Emacs development discussions To: Paul Eggert Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Thu Nov 08 14:31:21 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 1TWSCW-00079T-VL for ged-emacs-devel@m.gmane.org; Thu, 08 Nov 2012 14:31:21 +0100 Original-Received: from localhost ([::1]:49674 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TWSCN-0003nS-QM for ged-emacs-devel@m.gmane.org; Thu, 08 Nov 2012 08:31:11 -0500 Original-Received: from eggs.gnu.org ([208.118.235.92]:58659) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TWSCI-0003nK-Hb for emacs-devel@gnu.org; Thu, 08 Nov 2012 08:31:10 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TWSCC-0005kr-Gr for emacs-devel@gnu.org; Thu, 08 Nov 2012 08:31:06 -0500 Original-Received: from forward15.mail.yandex.net ([95.108.130.119]:33463) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TWSCC-0005kR-0P for emacs-devel@gnu.org; Thu, 08 Nov 2012 08:31:00 -0500 Original-Received: from smtp11.mail.yandex.net (smtp11.mail.yandex.net [95.108.130.67]) by forward15.mail.yandex.net (Yandex) with ESMTP id B56A49E2160; Thu, 8 Nov 2012 17:30:56 +0400 (MSK) Original-Received: from smtp11.mail.yandex.net (localhost [127.0.0.1]) by smtp11.mail.yandex.net (Yandex) with ESMTP id 7CCCA7E021A; Thu, 8 Nov 2012 17:30:56 +0400 (MSK) Original-Received: from unknown (unknown [37.139.80.10]) by smtp11.mail.yandex.net (nwsmtp/Yandex) with ESMTP id UtSSOdnS-UuSaufOL; Thu, 8 Nov 2012 17:30:56 +0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex.ru; s=mail; t=1352381456; bh=WfMcpJE2DVqqdAgqjaa8fG5QfZSkONjvboLkmNGSRgI=; h=Message-ID:Date:From:User-Agent:MIME-Version:To:CC:Subject: References:In-Reply-To:Content-Type:Content-Transfer-Encoding; b=AVxFS9faXCiO4/iQlvpYHSfX+3rzgkdxOnQJI0tJviye1bNY1XqMU5ZvXmngvloAJ D0xqw44Y8ugh0UalRhKgVeHHi0L+ea4+lYZZoeveR3qDerb3G8+3WmGEMxKP1fKOpb 38CTRfHNIW2k2ed6dPtf4CoFBYNdXM7zhNDHRyyo= User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:16.0) Gecko/20121026 Thunderbird/16.0.2 In-Reply-To: <509B4246.2050203@cs.ucla.edu> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.4.x-2.6.x [generic] [fuzzy] X-Received-From: 95.108.130.119 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:154731 Archived-At: On 11/08/2012 09:25 AM, Paul Eggert wrote: > But better yet would be to omit the casts entirely. > This might let GCC do more optimizations safely. That is, > change struct Lisp_Vector to be something like this: > > struct Lisp_Vector > { > struct vectorlike_header header; > union > { > Lisp_Object contents[1]; > struct Lisp_Vector *next; > } u; > }; This is the most clean way, but > Replace all current uses of 'contents' > with 'u.contents', is it worth doing such a massive change just to avoid one little glitch? Dmitry