From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Gregory Heytings Newsgroups: gmane.emacs.devel Subject: Re: Add more supported primitives in libgccjit IR (was: Shrinking the C core) Date: Mon, 21 Aug 2023 12:33:15 +0000 Message-ID: <77daee02cfb55dd073c1@heytings.org> References: <20230809094655.793FC18A4654@snark.thyrsus.com> <83fs4dwwdo.fsf@gnu.org> <874jkt90a5.fsf@localhost> <87y1i57jqi.fsf@localhost> <87pm3h7h8k.fsf@localhost> <87h6ot7cf3.fsf@localhost> <87edjx7c0b.fsf@localhost> <831qfxw2cx.fsf@gnu.org> <87v8d95918.fsf@localhost> <87zg2lav4b.fsf@yahoo.com> <87sf8d57wf.fsf@localhost> <87r0nxatu1.fsf@yahoo.com> <87pm3h56ig.fsf@localhost> <87edjxarhz.fsf@yahoo.com> <87edjw4uw4.fsf@localhost> <77daee02cf1ba0db70c1@heytings.org> <87v8d8fzr9.fsf@localhost> <77daee02cf12896f33b4@heytings.org> <87h6osfwjc.fsf@localhost> Mime-Version: 1.0 Content-Type: text/plain; format=flowed; charset=us-ascii Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="36716"; mail-complaints-to="usenet@ciao.gmane.io" Cc: Po Lu , Andrea Corallo , Eli Zaretskii , ams@gnu.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 14:33:57 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 1qY46T-0009C7-6m for ged-emacs-devel@m.gmane-mx.org; Mon, 21 Aug 2023 14:33:53 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qY460-0003Fu-KO; Mon, 21 Aug 2023 08:33:24 -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 1qY45x-0003FR-8N for emacs-devel@gnu.org; Mon, 21 Aug 2023 08:33:21 -0400 Original-Received: from heytings.org ([95.142.160.155]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qY45u-0003Ms-Qz; Mon, 21 Aug 2023 08:33:21 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=heytings.org; s=20220101; t=1692621195; bh=No3efZYJQ809cM017QxUiH9v+5oGR6iumQuSOmCHFLk=; h=Date:From:To:cc:Subject:In-Reply-To:Message-ID:References:From; b=6nCE5T9Z9BG3qCU9MIXIvcE6H/y2wxPrjUibqs6MG8p5j9BpMuaVt6ngBTwilxdF5 +OENoDVTUKY1lcsvkx8Cga+H+74co3Xm4HMsG37rmuiiulXx44ugWKZ31gq1HhiRi8 7FS66a3cdFaswAk5IrnRTgFQEHZxhWr6dCpwCdz9QCa15VISXkGh6OhWFTsPWkZEV6 c2Xa6gh6lt9OQIVH4jTqpIG0DIemWsqq5WeRot72jESnoWK68fXfOpX7xcHCUFQgsg SbvvK7KFvLyXHtqSGXEX1V04hOwwlOI7CkvsUbrExVt9tlnHISw3gXMXto85oQbi+o vezjstIEQUeWw== In-Reply-To: <87h6osfwjc.fsf@localhost> Received-SPF: pass client-ip=95.142.160.155; envelope-from=gregory@heytings.org; helo=heytings.org X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action 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:309072 Archived-At: >> Take this equally trivial example: >> >> (setq a most-positive-fixnum) >> (setq a (1+ a)) >> >> The 'a' object was an integer, and became a bignum. > > I understand. I doubt that Emacs native compiler checks this far. > However, such checks are definitely doable - integer bounds are not > unknown and can certainly be handled. > They cannot, certainly not in general. In the trivial example above the compiler could know that 'a' is most-positive-fixnum. But if you have a '1+' somewhere in an actual piece of code, you cannot, except in rare cases, know at compile time its argument (whose value may, for example, depend on the value of a function argument) is an integer and that adding 1 to that integer will not overflow.