From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.devel Subject: Re: pure-fns in byte-opt.el Date: Sat, 25 Jul 2020 16:59:39 -0400 Message-ID: References: <20170725020650.GA12601@holos.localdomain> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="6601"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.0.50 (gnu/linux) Cc: Richard Stallman , Emacs developers To: Philipp Stephani Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Sat Jul 25 23:00:26 2020 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 1jzRHN-0001d7-Vb for ged-emacs-devel@m.gmane-mx.org; Sat, 25 Jul 2020 23:00:25 +0200 Original-Received: from localhost ([::1]:37416 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jzRHM-0006wc-W9 for ged-emacs-devel@m.gmane-mx.org; Sat, 25 Jul 2020 17:00:25 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:56414) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jzRGk-0006X1-A4 for emacs-devel@gnu.org; Sat, 25 Jul 2020 16:59:46 -0400 Original-Received: from mailscanner.iro.umontreal.ca ([132.204.25.50]:37301) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jzRGi-0004s6-7Z; Sat, 25 Jul 2020 16:59:45 -0400 Original-Received: from pmg1.iro.umontreal.ca (localhost.localdomain [127.0.0.1]) by pmg1.iro.umontreal.ca (Proxmox) with ESMTP id 6BB551002FA; Sat, 25 Jul 2020 16:59:42 -0400 (EDT) Original-Received: from mail01.iro.umontreal.ca (unknown [172.31.2.1]) by pmg1.iro.umontreal.ca (Proxmox) with ESMTP id E635D1002CF; Sat, 25 Jul 2020 16:59:40 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=iro.umontreal.ca; s=mail; t=1595710780; bh=sMQuIwC+ctmYSZi7mWM2/giPckf7nllVI0G/qRP6fpo=; h=From:To:Cc:Subject:References:Date:In-Reply-To:From; b=GpqxXkzKL/cLCVWLrg4rKwRpUCJtxA4zO0V3cq4VxKWiUFjyK5729fWzZ58TtOn4v QhAc/uD1Dyr0xL0KKlG2Y/eflImEIXHa11cuZLDdgXXfIx3968vnvD3fKBMsPAO2gG PbzZT/LUFdGIElxiX4uGzySfhfJUQJiSTaNTxJx3sx8tYo7NVOmfpIJXONQUWjHKXa 1Zfn+6vaN8akSeCISopFDzZnYYVkJXFzkZyfsdOXvr5NbFwfL2zkfUPiEZ045+jk2T Fel8KLWv5dNgjLd1mp4ybKM+YUcHbr5jK61TRM7Dq25MnGKPEmJt0S19om5OceD5Ot Xaq0OuAsq7lOg== Original-Received: from milanesa (unknown [104.247.229.155]) by mail01.iro.umontreal.ca (Postfix) with ESMTPSA id B2324120784; Sat, 25 Jul 2020 16:59:40 -0400 (EDT) In-Reply-To: (Philipp Stephani's message of "Sat, 25 Jul 2020 22:08:36 +0200") Received-SPF: pass client-ip=132.204.25.50; envelope-from=monnier@iro.umontreal.ca; helo=mailscanner.iro.umontreal.ca X-detected-operating-system: by eggs.gnu.org: First seen = 2020/07/25 14:14:04 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] X-Spam_score_int: -42 X-Spam_score: -4.3 X-Spam_bar: ---- X-Spam_report: (-4.3 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, RCVD_IN_DNSWL_MED=-2.3, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.23 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" Xref: news.gmane.io gmane.emacs.devel:253237 Archived-At: >> The above "definition" seems to allow that: based on looking at the code >> you should be able to assess whether it's safe to allow the compiler (or >> anything else for that matter) to precompute the call. > I wouldn't know how that should be possible without knowing how the > compiler operates (or what it "knows" or can know). Why would you need to know that? As mentioned between parentheses it's not specific to a compiler. Is it that you find "precompute" unclear? > It relies on some (rather vague) terms about the compiler, such as > "precompute" and "know". What if we change the compiler significantly > so that it "knows" much more? Doesn't make a difference: it will just make it possible for the compiler to precompute more often, whereas what this flag says is "when the compiler is *able* to precompute the call, should it be *allowed* to do so". Stefan