From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: Shrinking the C core Date: Mon, 21 Aug 2023 14:10:46 +0300 Message-ID: <83ttssvefd.fsf@gnu.org> 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> <835y59wmp1.fsf@gnu.org> <877cpp7b3f.fsf@localhost> <83zg2lunp2.fsf@gnu.org> <87lee44w7c.fsf@localhost> Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="16047"; mail-complaints-to="usenet@ciao.gmane.io" Cc: ams@gnu.org, incal@dataswamp.org, emacs-devel@gnu.org To: Ihor Radchenko Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Mon Aug 21 13:11:02 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 1qY2oH-0003vg-9r for ged-emacs-devel@m.gmane-mx.org; Mon, 21 Aug 2023 13:11:01 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qY2ns-0007Zl-VJ; Mon, 21 Aug 2023 07:10:36 -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 1qY2np-0007Wo-8v for emacs-devel@gnu.org; Mon, 21 Aug 2023 07:10:33 -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 1qY2nn-0001ob-K0; Mon, 21 Aug 2023 07:10:32 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=gnu.org; s=fencepost-gnu-org; h=References:Subject:In-Reply-To:To:From:Date: mime-version; bh=l4o4bU8Q54CwAJrtRD4IrU9NssUlDJKFowGaj+J3STQ=; b=qgIgAZDA5Iz1 PBS7l7S1+tG5/VWS7BXlj8+zSt8TOqvnt58/hxJuHiEY4VMn0lfnUAcckJm7a4LQwpf9yTwID29AX P8f3/s13Bsdfni6CNXImVqXwzRPf66RX/jmPlYwdwvPiWyUqMfUnXJnprjjT0Dxv9Ldoj66B9IW0p CXfKL2Kw9Wxr34tmqpceWOW17d0ZY41mG5zVY0xou2r1VmIL/hEPOT5ZnQnhC8FOcrQeGQOKlpyzg GJFiGcSnoPKufb7eUSp531oaR2XaJY+h0zRh2GH8DbRQkmStVIuAQIzNcjMGgS/QNpfVw7M0lKbGL LQB6WKWriiAM5fGW3Vtckg==; In-Reply-To: <87lee44w7c.fsf@localhost> (message from Ihor Radchenko on Mon, 21 Aug 2023 08:48:55 +0000) 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:309055 Archived-At: > From: Ihor Radchenko > Cc: ams@gnu.org, incal@dataswamp.org, emacs-devel@gnu.org > Date: Mon, 21 Aug 2023 08:48:55 +0000 > > >> Then, I conclude that the example with CL version of `car' is actually > >> not worse in Elisp: > > > > I think you forget the price of running the interpreter. After > > computing the value of 'car', the code must use it, and that's where > > the difference comes from. Look at bytecode.c, from which I quoted a > > tiny fragment, to see what Emacs does with the results of each > > op-code. (It's actually what every byte-code machine out there does.) > > Do I understand correctly that the extra staff that has to be done by > the byte-code machine is register manipulation? Which registers do you have in mind here? bytecode.c implements a stack-based machine, see the comments and "ASCII-art" picture around line 340 in bytecode.c. Then study the macros used in bytecode.c, like TOP, PUSH, etc., and you will see what I mean. > If so, the assembly will probably look similar I don't think so. You can compare the GDB disassembly with the results of byte-code disassembly (the "M-x disassemble" command in Emacs), and I'm quite sure you will see the results are very different.