From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: Paul Eggert Newsgroups: gmane.emacs.devel Subject: Re: Crashes in "C-h h" Date: Fri, 5 Jul 2019 20:42:09 -0700 Organization: UCLA Computer Science Department Message-ID: References: <83y31hes6r.fsf@gnu.org> <83r279epwe.fsf@gnu.org> <09f72051-d740-9115-c6fd-c4344c749568@cs.ucla.edu> <83muhvd9nm.fsf@gnu.org> <9b78b85d-a3c8-761f-e500-d51d4a985fa8@cs.ucla.edu> <83k1cybk8c.fsf@gnu.org> <83ef36ar0p.fsf@gnu.org> <5e9b9214-4ccd-68a4-2016-7ac3ea8a06d9@cs.ucla.edu> <83wogwapf7.fsf@gnu.org> <83sgrkanbo.fsf@gnu.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="121166"; mail-complaints-to="usenet@blaine.gmane.org" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.2 Cc: emacs-devel@gnu.org To: Eli Zaretskii , Pip Cet Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Sat Jul 06 05:42:32 2019 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([209.51.188.17]) by blaine.gmane.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1hjban-000VLh-2J for ged-emacs-devel@m.gmane.org; Sat, 06 Jul 2019 05:42:29 +0200 Original-Received: from localhost ([::1]:57554 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hjbam-0006Fi-2o for ged-emacs-devel@m.gmane.org; Fri, 05 Jul 2019 23:42:28 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:48584) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hjbah-0006FY-46 for emacs-devel@gnu.org; Fri, 05 Jul 2019 23:42:24 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hjbag-00056n-85 for emacs-devel@gnu.org; Fri, 05 Jul 2019 23:42:23 -0400 Original-Received: from zimbra.cs.ucla.edu ([131.179.128.68]:45782) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hjbaZ-000508-VL; Fri, 05 Jul 2019 23:42:17 -0400 Original-Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id 0B1BF1626AC; Fri, 5 Jul 2019 20:42:11 -0700 (PDT) Original-Received: from zimbra.cs.ucla.edu ([127.0.0.1]) by localhost (zimbra.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id InN9lA_fmGR2; Fri, 5 Jul 2019 20:42:10 -0700 (PDT) Original-Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id 47E671626B8; Fri, 5 Jul 2019 20:42:10 -0700 (PDT) X-Virus-Scanned: amavisd-new at zimbra.cs.ucla.edu Original-Received: from zimbra.cs.ucla.edu ([127.0.0.1]) by localhost (zimbra.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id EY6nHreTxspt; Fri, 5 Jul 2019 20:42:10 -0700 (PDT) Original-Received: from [192.168.1.9] (cpe-23-242-74-103.socal.res.rr.com [23.242.74.103]) by zimbra.cs.ucla.edu (Postfix) with ESMTPSA id 1EB401626AC; Fri, 5 Jul 2019 20:42:10 -0700 (PDT) In-Reply-To: <83sgrkanbo.fsf@gnu.org> Content-Language: en-US X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 131.179.128.68 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.23 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:238374 Archived-At: Eli Zaretskii wrote: > It is not useful to compare to a function that does nothing. It's standard in benchmarking to do that, to try to distinguish the overhead of running the benchmark from the code one is actually trying to measure. > Useful > comparisons would be with functions that do this: > > return x == y; That depends on what one means by "useful". I was trying to compare the performance of EQ+make_fixnum to that of FIXNUMP+XFIXNUM, not to that of ==. > comparing with make_fixnum, i.e. > > EQ (x, make_fixnum (n)) > > is TRT when you are NOT certain that X is a fixnum ... > If you ARE certain that X is a fixnum, then > > XFIXNUM (x) == n > > is also OK. Yes, that's right. > The comparison with > > if (FIXNUMP (x) && XFIXNUM (x) == n) > > is IMO not useful, because it should be clear up front that it will > always lose due to the additional test. I suspect much of this thread is due to a misunderstanding then, as I interpreted your earlier comment "It normally shouldn't matter either way" to mean the opposite, which is why I ran the benchmarks. Apparently my interpretation was a misunderstanding of what you intended. It is amusing that those benchmarks yield such wildly-different results on different CPUs, though.