From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Tom Tromey Newsgroups: gmane.emacs.devel Subject: Re: Inefficiency in Bgotoifnil byte-code instruction Date: Fri, 06 Jul 2012 14:27:47 -0600 Message-ID: <877gugmy7w.fsf@fleche.redhat.com> References: <87k3yq2htz.fsf@fleche.redhat.com> <87y5n2vupa.fsf@fleche.redhat.com> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: dough.gmane.org 1341606480 26044 80.91.229.3 (6 Jul 2012 20:28:00 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Fri, 6 Jul 2012 20:28:00 +0000 (UTC) Cc: emacs-devel@gnu.org To: Stefan Monnier Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Fri Jul 06 22:27:59 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 1SnF88-0000vV-Er for ged-emacs-devel@m.gmane.org; Fri, 06 Jul 2012 22:27:56 +0200 Original-Received: from localhost ([::1]:46903 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SnF87-0003K3-BM for ged-emacs-devel@m.gmane.org; Fri, 06 Jul 2012 16:27:55 -0400 Original-Received: from eggs.gnu.org ([208.118.235.92]:54835) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SnF84-0003Jy-Lc for emacs-devel@gnu.org; Fri, 06 Jul 2012 16:27:53 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SnF83-0006ty-2O for emacs-devel@gnu.org; Fri, 06 Jul 2012 16:27:52 -0400 Original-Received: from mx1.redhat.com ([209.132.183.28]:18925) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SnF82-0006tr-Q6 for emacs-devel@gnu.org; Fri, 06 Jul 2012 16:27:50 -0400 Original-Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id q66KRnBi008913 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Fri, 6 Jul 2012 16:27:49 -0400 Original-Received: from barimba (ovpn01.gateway.prod.ext.phx2.redhat.com [10.5.9.1]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id q66KRlWs022800 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO); Fri, 6 Jul 2012 16:27:48 -0400 X-Attribution: Tom In-Reply-To: (Stefan Monnier's message of "Tue, 03 Jul 2012 09:19:53 -0400") User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.1 (gnu/linux) X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 209.132.183.28 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:151468 Archived-At: Stefan> There's a lot of room for improvement in the regexp-matcher as Stefan> well, yes. If we could generate the code via something like Stefan> vmgen it would be even better. Yeah. Translating the bytecode engine to vmgen is not trivial, but at first blush it seems doable. This would have a few possible advantages -- TOS caching, superinstructions, possibly better micro-optimization. I didn't look at the regexp matcher with this in mind. It also occurred to me recently that the computed goto treatment could perhaps be applied to mark_object. Tom