From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from joooj.vinc17.net (joooj.vinc17.net [155.133.131.76]) by sourceware.org (Postfix) with ESMTPS id 1C7D8385841A for ; Fri, 16 Feb 2024 10:23:00 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 1C7D8385841A Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=vinc17.net Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=vinc17.net ARC-Filter: OpenARC Filter v1.0.0 sourceware.org 1C7D8385841A Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=155.133.131.76 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1708078981; cv=none; b=IOf2xWGuuKo0XTNTcow2zHz5l1ziWANE+ztjxzryMYmCOHdsBqcos6R7KHLx6v9+cGgq2ck+QPaDuaBDo2WnE/SXTDTtIFqBl3a7spkZ/554c/b/ODHMHBYwF7SQnF+XrOkDsLdV+dOTKr/J5tINbYXh3HhQDPxieH1LtQF/+HE= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1708078981; c=relaxed/simple; bh=dwlDMEzwJZWX0GXeRJxrh/Xkn8GxrnN7O5Dd9utWRPY=; h=Date:From:To:Subject:Message-ID:MIME-Version; b=ZTSzGmw5vFyH8zV6l8wiC/dn9zO2g03/pTYALKXIA16FW2QR+7NBlRajn13tJ4l5gUqAAKOqGF9vfPX0BQ4mpT8Tk0RBlGuRDGsIBZrVN0ME4tAIZFAvCcFurnGMkfnPwBt41K6OKy2xeaXtht3wBgAry1j2CdSSHgWSNkjtn9Y= ARC-Authentication-Results: i=1; server2.sourceware.org Received: from smtp-qaa.vinc17.net (2a02-8428-1b1d-4d01-96a9-491d-7b48-ba31.rev.sfr.net [IPv6:2a02:8428:1b1d:4d01:96a9:491d:7b48:ba31]) by joooj.vinc17.net (Postfix) with ESMTPSA id 002E31F2; Fri, 16 Feb 2024 11:22:58 +0100 (CET) Received: by qaa.vinc17.org (Postfix, from userid 1000) id B5B78CA3237; Fri, 16 Feb 2024 11:22:58 +0100 (CET) Date: Fri, 16 Feb 2024 11:22:58 +0100 From: Vincent Lefevre To: libc-alpha@sourceware.org Subject: Re: document the fact that "Known Maximum Errors" might not be maximal Message-ID: <20240216102258.GB3653@qaa.vinc17.org> Mail-Followup-To: Vincent Lefevre , libc-alpha@sourceware.org References: <20240216094334.GA3653@qaa.vinc17.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Mailer-Info: https://www.vinc17.net/mutt/ User-Agent: Mutt/2.2.12+69 (354c5b11) vl-149028 (2023-12-10) X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,KAM_DMARC_STATUS,SPF_HELO_NONE,SPF_PASS,TXREP,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: On 2024-02-16 11:02:40 +0100, Paul Zimmermann wrote: > Hi Vincent, > > > Instead of saying that they are "documented elsewhere", shouldn't the > > manual be updated? > > this is one solution I proposed in > https://sourceware.org/pipermail/libc-alpha/2023-December/153279.html, > and Carlos answered: > > > (a) There are known defects where ULPs may reach values that are not useful > > for talking about the library in general. > > > > (b) There is value in being clear about the worst case known ULPs for an > > implementation of a given algorithm. > > > > If a test is marked as XFAIL then it is clearly (a) and listing that worst > > case ULPs in the manual may not be useful. > > thus the proposed patch documents the existence of the "XFAIL" entries. If I understand correctly, Carlos means (unintended) bugs, in which case, values may even be completely wrong (as already seen). I think that saying "documented elsewhere" is misleading. And note that bugs are not specific to the math functions. Any buggy library function will not behave as described in the manual. You should rather say that the given bounds obviously do not take bugs into account, if you think that this is worth recalling. -- Vincent Lefèvre - Web: 100% accessible validated (X)HTML - Blog: Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)