From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Richard Stallman Newsgroups: gmane.emacs.devel Subject: Re: Some vars now limited to fixnum size. (Was: Merging bignum to master) Date: Wed, 22 Aug 2018 00:03:05 -0400 Message-ID: References: <877ekwu1mn.fsf@tromey.com> <611579fd-52f2-0104-ef82-a7a4a3929700@cs.ucla.edu> <878t51t32a.fsf_-_@red-bean.com> <28fcabff-d102-d67f-442f-f59eab5040c9@cs.ucla.edu> <6bb0eda0-b408-242c-f584-9b358188af93@cs.ucla.edu> Reply-To: rms@gnu.org NNTP-Posting-Host: blaine.gmane.org Content-Type: text/plain; charset=Utf-8 X-Trace: blaine.gmane.org 1534910648 2238 195.159.176.226 (22 Aug 2018 04:04:08 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Wed, 22 Aug 2018 04:04:08 +0000 (UTC) Cc: kfogel@red-bean.com, tom@tromey.com, pipcet@gmail.com, emacs-devel@gnu.org To: Paul Eggert Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Wed Aug 22 06:04:03 2018 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1fsKNH-0000NN-JA for ged-emacs-devel@m.gmane.org; Wed, 22 Aug 2018 06:04:03 +0200 Original-Received: from localhost ([::1]:56801 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fsKPM-0005vJ-Bo for ged-emacs-devel@m.gmane.org; Wed, 22 Aug 2018 00:06:12 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:39676) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fsKNE-0004Wt-S4 for emacs-devel@gnu.org; Wed, 22 Aug 2018 00:04:02 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fsKN7-0006mP-06 for emacs-devel@gnu.org; Wed, 22 Aug 2018 00:03:55 -0400 Original-Received: from fencepost.gnu.org ([2001:4830:134:3::e]:51395) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fsKMO-0005wZ-WB; Wed, 22 Aug 2018 00:03:10 -0400 Original-Received: from rms by fencepost.gnu.org with local (Exim 4.82) (envelope-from ) id 1fsKML-0002Zn-8j; Wed, 22 Aug 2018 00:03:06 -0400 In-Reply-To: <6bb0eda0-b408-242c-f584-9b358188af93@cs.ucla.edu> (message from Paul Eggert on Mon, 20 Aug 2018 21:09:12 -0700) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 2001:4830:134:3::e X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.21 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" Xref: news.gmane.org gmane.emacs.devel:228796 Archived-At: [[[ To any NSA and FBI agents reading my email: please consider ]]] [[[ whether defending the US Constitution against all enemies, ]]] [[[ foreign or domestic, requires you to follow Snowden's example. ]]] > (setq circular (list 1 2)) > (setcdr (last circular) circular) > (setq n (ash 1 61)) > (nthcdr n bench-circular) > On my circa-2010 64-bit desktop with Emacs master, the nthcdr call consumes 160 How does it do the job so fast? Does it calculate the length of the list, then divide? -- Dr Richard Stallman President, Free Software Foundation (https://gnu.org, https://fsf.org) Internet Hall-of-Famer (https://internethalloffame.org)