From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: VIRT_ADDR_VARIES Date: Thu, 10 Nov 2011 20:06:27 +0200 Message-ID: <83bosjhmxo.fsf@gnu.org> References: <4EB73983.1060000@cs.ucla.edu> <4EB86864.5080709@cs.ucla.edu> <4EB96841.7020701@cs.ucla.edu> <4EB99C7D.8000407@cs.ucla.edu> <4EBABBF5.5030602@cs.ucla.edu> <4EBB8882.6080504@cs.ucla.edu> <4EBBFBF7.2030107@cs.ucla.edu> <83d3d0gc85.fsf@gnu.org> <4EBC00DF.3010906@cs.ucla.edu> Reply-To: Eli Zaretskii NNTP-Posting-Host: lo.gmane.org X-Trace: dough.gmane.org 1320948552 30093 80.91.229.12 (10 Nov 2011 18:09:12 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Thu, 10 Nov 2011 18:09:12 +0000 (UTC) Cc: emacs-devel@gnu.org To: Paul Eggert Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Thu Nov 10 19:09:08 2011 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([140.186.70.17]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1ROZ3k-0003Q0-H6 for ged-emacs-devel@m.gmane.org; Thu, 10 Nov 2011 19:09:08 +0100 Original-Received: from localhost ([::1]:42557 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ROZ3j-0006FQ-KT for ged-emacs-devel@m.gmane.org; Thu, 10 Nov 2011 13:09:07 -0500 Original-Received: from eggs.gnu.org ([140.186.70.92]:35013) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ROZ3h-0006FH-8P for emacs-devel@gnu.org; Thu, 10 Nov 2011 13:09:06 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ROZ3f-0001vd-Fw for emacs-devel@gnu.org; Thu, 10 Nov 2011 13:09:04 -0500 Original-Received: from mtaout21.012.net.il ([80.179.55.169]:36625) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ROZ3f-0001uw-9a for emacs-devel@gnu.org; Thu, 10 Nov 2011 13:09:03 -0500 Original-Received: from conversion-daemon.a-mtaout21.012.net.il by a-mtaout21.012.net.il (HyperSendmail v2007.08) id <0LUG00900I8BBA00@a-mtaout21.012.net.il> for emacs-devel@gnu.org; Thu, 10 Nov 2011 20:08:25 +0200 (IST) Original-Received: from HOME-C4E4A596F7 ([84.228.182.120]) by a-mtaout21.012.net.il (HyperSendmail v2007.08) with ESMTPA id <0LUG009NTIE0AL30@a-mtaout21.012.net.il>; Thu, 10 Nov 2011 20:08:25 +0200 (IST) In-reply-to: <4EBC00DF.3010906@cs.ucla.edu> X-012-Sender: halo1@inter.net.il X-detected-operating-system: by eggs.gnu.org: Solaris 10 (beta) X-Received-From: 80.179.55.169 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:145978 Archived-At: > Date: Thu, 10 Nov 2011 08:50:39 -0800 > From: Paul Eggert > CC: emacs-devel@gnu.org > > On 11/10/11 08:43, Eli Zaretskii wrote: > > But why would someone do such a thing? > > Performance. > > Comparing against my_edata takes just one instruction. > Comparing against both the start and the end of 'pure' > takes two comparisons and some glue instructions and > typically includes a conditional branch. I'm surprised. Saving a few instructions in something that is never called inside any time-critical code would be more than just premature optimization in my book.