From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: "Alfred M. Szmidt" Newsgroups: gmane.emacs.devel Subject: Re: Shrinking the C core Date: Sun, 20 Aug 2023 16:11:54 -0400 Message-ID: References: <20230809094655.793FC18A4654@snark.thyrsus.com> <87jztzkgct.fsf@dataswamp.org> <87y1if8j8t.fsf@linux-m68k.org> <87y1ifi9fv.fsf@dataswamp.org> <87zg2uqdmv.fsf@localhost> <87edk3gbh3.fsf@dataswamp.org> <87jztvnuyb.fsf@localhost> <875y5bdutt.fsf@dataswamp.org> <87y1i6e1uh.fsf@localhost> <874jkub40o.fsf@dataswamp.org> <87jztqdw2l.fsf@localhost> <87msym9i4r.fsf@dataswamp.org> <877cpp914t.fsf@localhost> <871qfx8yfq.fsf@localhost> <87sf8d7hj0.fsf@localhost> <838ra5wn8r.fsf@gnu.org> Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="20871"; mail-complaints-to="usenet@ciao.gmane.io" Cc: yantar92@posteo.net, incal@dataswamp.org, emacs-devel@gnu.org To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Sun Aug 20 22:12:55 2023 Return-path: Envelope-to: ged-emacs-devel@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1qXon8-0005G1-Ud for ged-emacs-devel@m.gmane-mx.org; Sun, 20 Aug 2023 22:12:55 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qXomD-0003vR-3D; Sun, 20 Aug 2023 16:11:57 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qXomB-0003v6-4k for emacs-devel@gnu.org; Sun, 20 Aug 2023 16:11:55 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qXomA-0001Rc-I1; Sun, 20 Aug 2023 16:11:54 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=gnu.org; s=fencepost-gnu-org; h=Date:References:Subject:In-Reply-To:To:From: mime-version; bh=a1tiVdzbr3o97qGninbSB46iS4nwdL64L2del3fbiOg=; b=jaiflM1cFFV+ olKO+T9urYBh/5eKmCnSw5oPivwV3f+RW5woN4ImCGUijoOYfFnWayqg7kQ/liGQoCOZyxeGEG/vr mHRttav3cH45we1SAxga7gX4BW1Cgom6Uhz+jPZqRj5YHzCbe4GaPCrwl2Ac38l8bjn8iIGzVXr6F UO8LiyW4vyFc/gFV9zk1mTF/jepMgyMrdJMIJT8xI6Mo7P+p5NbqtlpR0h0tSi6rz56lGY6gREq9C OZkAwj5SudB62wXXMmqdAoNs9qEahSQGpc5pXlwxRK3wQf2Bb3ewvgOFZfpXKbXNUll7m9YfxP8uY 9uvTWnXrQbtU6+OVqi3e/Q==; Original-Received: from ams by fencepost.gnu.org with local (Exim 4.90_1) (envelope-from ) id 1qXomA-00055z-9p; Sun, 20 Aug 2023 16:11:54 -0400 In-Reply-To: <838ra5wn8r.fsf@gnu.org> (message from Eli Zaretskii on Sun, 20 Aug 2023 22:02:44 +0300) X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.29 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-mx.org@gnu.org Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.devel:308993 Archived-At: > From: "Alfred M. Szmidt" > Cc: incal@dataswamp.org, emacs-devel@gnu.org > Date: Sun, 20 Aug 2023 14:54:43 -0400 > > > Does not look too bad in terms of the number of instructions. And I do > > not see any obvious indirection. > > > > The Emacs VM will incure a switch to C for each call, SBCL doesn't. > > You really cannot see the difference that makes? > > May you elaborate what you mean by "switch to C"? > Emacs VM is running in C already. > > How does the decoding of bytecode to C happen? It doesn't. bytecode.c is already written in C. Tardy wording on my side, Emacs has to loop over the byte code to execute it, and then maybe call C or Lisp depending. While SBCL will compile everything to whatever the target architecture is -- so no bytecode is involved, and that (small) indirection is avoided since it all becomes a normal function call.