From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: ludo@gnu.org (Ludovic =?iso-8859-1?Q?Court=E8s?=) Newsgroups: gmane.lisp.guile.devel Subject: Re: Register VM WIP Date: Wed, 16 May 2012 22:39:44 +0200 Message-ID: <87likr273j.fsf@gnu.org> References: <871umqr8q0.fsf@pobox.com> <873972zczy.fsf@gnu.org> <87bolpmgew.fsf@pobox.com> <871umkbvp3.fsf@netris.org> <87fwb0k35g.fsf@pobox.com> <87sjf09r5v.fsf@netris.org> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Trace: dough.gmane.org 1337200798 32341 80.91.229.3 (16 May 2012 20:39:58 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Wed, 16 May 2012 20:39:58 +0000 (UTC) Cc: Andy Wingo , Mark H Weaver , guile-devel@gnu.org To: Noah Lavine Original-X-From: guile-devel-bounces+guile-devel=m.gmane.org@gnu.org Wed May 16 22:39:57 2012 Return-path: Envelope-to: guile-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 1SUl0k-0003lR-UW for guile-devel@m.gmane.org; Wed, 16 May 2012 22:39:55 +0200 Original-Received: from localhost ([::1]:50896 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SUl0k-00056o-CE for guile-devel@m.gmane.org; Wed, 16 May 2012 16:39:54 -0400 Original-Received: from eggs.gnu.org ([208.118.235.92]:37844) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SUl0g-00056e-EZ for guile-devel@gnu.org; Wed, 16 May 2012 16:39:51 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SUl0e-0002Ic-2w for guile-devel@gnu.org; Wed, 16 May 2012 16:39:50 -0400 Original-Received: from xanadu.aquilenet.fr ([88.191.123.111]:58773) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SUl0d-0002IH-TR for guile-devel@gnu.org; Wed, 16 May 2012 16:39:48 -0400 Original-Received: from localhost (localhost [127.0.0.1]) by xanadu.aquilenet.fr (Postfix) with ESMTP id EA1CCD4D8; Wed, 16 May 2012 22:39:45 +0200 (CEST) Original-Received: from xanadu.aquilenet.fr ([127.0.0.1]) by localhost (xanadu.aquilenet.fr [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id OwDtUyox5XzV; Wed, 16 May 2012 22:39:45 +0200 (CEST) Original-Received: from pluto (reverse-83.fdn.fr [80.67.176.83]) by xanadu.aquilenet.fr (Postfix) with ESMTPSA id 042D3D48E; Wed, 16 May 2012 22:39:44 +0200 (CEST) X-URL: http://www.fdn.fr/~lcourtes/ X-Revolutionary-Date: 28 =?iso-8859-1?Q?Flor=E9al?= an 220 de la =?iso-8859-1?Q?R=E9volution?= X-PGP-Key-ID: 0xEA52ECF4 X-PGP-Key: http://www.fdn.fr/~lcourtes/ludovic.asc X-PGP-Fingerprint: 83C4 F8E5 10A3 3B4C 5BEA D15D 77DD 95E2 EA52 ECF4 X-OS: x86_64-unknown-linux-gnu In-Reply-To: (Noah Lavine's message of "Wed, 16 May 2012 10:54:37 -0400") User-Agent: Gnus/5.110018 (No Gnus v0.18) Emacs/24.0.93 (gnu/linux) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 3) X-Received-From: 88.191.123.111 X-BeenThere: guile-devel@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "Developers list for Guile, the GNU extensibility library" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: guile-devel-bounces+guile-devel=m.gmane.org@gnu.org Original-Sender: guile-devel-bounces+guile-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.lisp.guile.devel:14477 Archived-At: Hi, Noah Lavine skribis: > I think what Andy is proposing to do is to get rid of the > temporary-variable stack and operate directly on the local-variable > stack. We shouldn't think of these registers as being like machine > registers, and in fact maybe "registers" is not a good name for these > objects. They are really just variables in the topmost stack frame. Yeah, I too was confused the first time I heard about =E2=80=9Cregister VMs= .=E2=80=9D The key idea is that opcodes encode the offset of the operand they work on, rather than working only on the last words of the stack (for example, =E2=80=98add x y=E2=80=99 instead of =E2=80=98local-ref x=E2=80=99 + =E2=80= =98local-ref y=E2=80=99 + =E2=80=98add=E2=80=99 + =E2=80=98local-set x=E2= =80=99.) Thanks, Ludo=E2=80=99.