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 05:33:50 +0300 Message-ID: <831qfxw2cx.fsf@gnu.org> References: <20230809094655.793FC18A4654@snark.thyrsus.com> <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> <83fs4dwwdo.fsf@gnu.org> <874jkt90a5.fsf@localhost> <87y1i57jqi.fsf@localhost> <87pm3h7h8k.fsf@localhost> <87h6ot7cf3.fsf@localhost> <87edjx7c0b.fsf@localhost> Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="22622"; 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 04:34:35 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 1qXukV-0005ha-1z for ged-emacs-devel@m.gmane-mx.org; Mon, 21 Aug 2023 04:34:35 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qXujg-0004kF-8s; Sun, 20 Aug 2023 22:33:44 -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 1qXujb-0004k1-Lm for emacs-devel@gnu.org; Sun, 20 Aug 2023 22:33:39 -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 1qXujX-0004t1-7U; Sun, 20 Aug 2023 22:33:35 -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=Erq+8tIE3VObkaX0eXqe2DwOeZBFberWs78b7OW5M7k=; b=qZA7zdPkvohz DEUplEiAX1/BwSRl/GqDq27kNJIQGcR3a/H/pYPUDAxXFryPgK9We56BjsSQorKPnNzYuvFn1Ruyo nsx/oxnGyKGMQ/lj8nwiyCfSI2j5LYQuowlDs06vuyEbJ5ffAwzLfQkBRz4zJK2wyp5HmC3fSpVD9 OGwFEi0X98L0TZnjWCqYdSh/FQ9Q1A1ojCkUTgt+Z0SM7WWqvWr4x3iPN+TrH6ghVN+xsP7pl46AD jYWKla+imeDtGfUXFMVG0Aq9Yt6U7qZUyRtZj+MleJ7paihFXNjySAgdAQYLkQExlHXHoit1NUqU/ 3YTwYZt7ldGxhwAGmj5EmA==; In-Reply-To: <87edjx7c0b.fsf@localhost> (message from Ihor Radchenko on Sun, 20 Aug 2023 19:24:36 +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:309012 Archived-At: > From: Ihor Radchenko > Cc: eliz@gnu.org, incal@dataswamp.org, emacs-devel@gnu.org > Date: Sun, 20 Aug 2023 19:24:36 +0000 > > If I am right here, it might actually be worth it to rewrite some of the > subroutines into Elisp. For example rounding_driver (called by > `floor') code is full of runtime type checks: > > CHECK_NUMBER (n); > if (NILP (d)) > ... > CHECK_NUMBER (d); > ... > if (FIXNUMP (d)) > if (XFIXNUM (d) == 0) > ... > if (FIXNUMP (n)) > ... > else if (FLOATP (d)) > if (XFLOAT_DATA (d) == 0) > int nscale = FLOATP (n) ? double_integer_scale (XFLOAT_DATA (n)) : 0; > .. > > During native compilation, if type information and n and d is available, > GCC might have a chance to cut a number of branches away from the above > code. Cut them how? AFAICT, none of the tests above are redundant.