From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.devel Subject: Re: [PATCH]: Add new bytecode op `switch' for implementing branch tables. Date: Mon, 06 Feb 2017 13:30:56 -0500 Message-ID: References: NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: blaine.gmane.org 1486405902 22268 195.159.176.226 (6 Feb 2017 18:31:42 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Mon, 6 Feb 2017 18:31:42 +0000 (UTC) User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.0.50 (gnu/linux) To: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Mon Feb 06 19:31:39 2017 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 1cao4g-0005az-Uw for ged-emacs-devel@m.gmane.org; Mon, 06 Feb 2017 19:31:39 +0100 Original-Received: from localhost ([::1]:50167 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cao4m-0007nY-Io for ged-emacs-devel@m.gmane.org; Mon, 06 Feb 2017 13:31:44 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:33138) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cao4D-0007n8-34 for emacs-devel@gnu.org; Mon, 06 Feb 2017 13:31:09 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cao49-0000qG-6u for emacs-devel@gnu.org; Mon, 06 Feb 2017 13:31:09 -0500 Original-Received: from [195.159.176.226] (port=54865 helo=blaine.gmane.org) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1cao49-0000q3-04 for emacs-devel@gnu.org; Mon, 06 Feb 2017 13:31:05 -0500 Original-Received: from list by blaine.gmane.org with local (Exim 4.84_2) (envelope-from ) id 1cao41-0003sG-1m for emacs-devel@gnu.org; Mon, 06 Feb 2017 19:30:57 +0100 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 13 Original-X-Complaints-To: usenet@blaine.gmane.org Cancel-Lock: sha1:CYYg2t0rr8LR6x1KiI442YHsF/8= X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 195.159.176.226 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:212055 Archived-At: > The following patch adds support for a new op `switch` to the Emacs > bytecode VM and compiler. I guess the motivation is to speed up some code. Did you make any measurements to see what kind of effect it has? > However, since switch replaces all goto-if-nil code, I've used a few Hmm... so goto-if-nil is never used any more? Aren't there cases where byte-switch results in slower code than goto-if-nil? Stefan