From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Original-To: caml-list@sympa.inria.fr Delivered-To: caml-list@sympa.inria.fr Received: from mail2-relais-roc.national.inria.fr (mail2-relais-roc.national.inria.fr [192.134.164.83]) by sympa.inria.fr (Postfix) with ESMTPS id F0A2C7FD0C for ; Tue, 8 Nov 2016 11:00:31 +0100 (CET) Authentication-Results: mail2-smtp-roc.national.inria.fr; spf=None smtp.pra=goswin-v-b@web.de; spf=Pass smtp.mailfrom=goswin-v-b@web.de; spf=None smtp.helo=postmaster@mout.web.de Received-SPF: None (mail2-smtp-roc.national.inria.fr: no sender authenticity information available from domain of goswin-v-b@web.de) identity=pra; client-ip=212.227.15.4; receiver=mail2-smtp-roc.national.inria.fr; envelope-from="goswin-v-b@web.de"; x-sender="goswin-v-b@web.de"; x-conformance=sidf_compatible Received-SPF: Pass (mail2-smtp-roc.national.inria.fr: domain of goswin-v-b@web.de designates 212.227.15.4 as permitted sender) identity=mailfrom; client-ip=212.227.15.4; receiver=mail2-smtp-roc.national.inria.fr; envelope-from="goswin-v-b@web.de"; x-sender="goswin-v-b@web.de"; x-conformance=sidf_compatible; x-record-type="v=spf1" Received-SPF: None (mail2-smtp-roc.national.inria.fr: no sender authenticity information available from domain of postmaster@mout.web.de) identity=helo; client-ip=212.227.15.4; receiver=mail2-smtp-roc.national.inria.fr; envelope-from="goswin-v-b@web.de"; x-sender="postmaster@mout.web.de"; x-conformance=sidf_compatible IronPort-PHdr: =?us-ascii?q?9a23=3A9zBzhxCUKG0NNkqWxg5XUyQJP3N1i/DPJgcQr6Af?= =?us-ascii?q?oPdwSP7zpsbcNUDSrc9gkEXOFd2CrakV0ayH7uu5AzxIyK3CmUhKSIZLWR4BhJ?= =?us-ascii?q?detC0bK+nBN3fGKuX3ZTcxBsVIWQwt1Xi6NU9IBJS2PAWK8TWM5DIfUi/yKRBy?= =?us-ascii?q?brysXNWD1YLmiqvroc2bSj4LrQL1Wal1IhSyoFeZnegtqqwmFJwMzADUqGBDYe?= =?us-ascii?q?VcyDAgD1uSmxHh+pX4p8Y7oGx48sgs/M9YUKj8Y79wDfkBVGxnYCgJ45ihjxjI?= =?us-ascii?q?TQKV6jMjFEBQ2jhPBQXeplmuRJb6sgPzsOxwyCiTe8rsQuZndy6l6vJETwT3iS?= =?us-ascii?q?FPKTk/uEvNh8B9lqZcv1r1qBtk3I/SJZ/QPtJhc6mbcd5MFjkJZdpYSyEUWtD0?= =?us-ascii?q?VIAIFedUeL8A94Q=3D?= X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: =?us-ascii?q?A0ARAAAjoSFYhwQP49RdGgEBAQECAQEBA?= =?us-ascii?q?QgBAQEBFgEBAQMBAQEJAQEBgwQBAQEBAXd/jTmXAowViD6CCCmFewKCEj8UAQE?= =?us-ascii?q?BAQEBAQEBAQESAQEBCA0JCR0wgjMEARUBBIIQAQEEOj8QCxgJJQ8FKCGIVAEeC?= =?us-ascii?q?rRdhw0fhBwBAQEBAQUBAQEBAR0FixOHeIIvBYhIh06KGIY2igaJdQqGII0thAY?= =?us-ascii?q?egUyDJ4FpcQGFa4FOAQEB?= X-IPAS-Result: =?us-ascii?q?A0ARAAAjoSFYhwQP49RdGgEBAQECAQEBAQgBAQEBFgEBAQM?= =?us-ascii?q?BAQEJAQEBgwQBAQEBAXd/jTmXAowViD6CCCmFewKCEj8UAQEBAQEBAQEBAQESA?= =?us-ascii?q?QEBCA0JCR0wgjMEARUBBIIQAQEEOj8QCxgJJQ8FKCGIVAEeCrRdhw0fhBwBAQE?= =?us-ascii?q?BAQUBAQEBAR0FixOHeIIvBYhIh06KGIY2igaJdQqGII0thAYegUyDJ4FpcQGFa?= =?us-ascii?q?4FOAQEB?= X-IronPort-AV: E=Sophos;i="5.31,609,1473112800"; d="scan'208";a="244050009" Received: from mout.web.de ([212.227.15.4]) by mail2-smtp-roc.national.inria.fr with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 08 Nov 2016 11:00:31 +0100 Received: from frosties.localnet ([78.43.233.192]) by smtp.web.de (mrweb004) with ESMTPSA (Nemesis) id 0MaYGX-1cNeYJ1C4f-00K8RE; Tue, 08 Nov 2016 11:00:30 +0100 Received: from mrvn by frosties.localnet with local (Exim 4.87) (envelope-from ) id 1c43Cf-0004tp-GY; Tue, 08 Nov 2016 11:00:29 +0100 Date: Tue, 8 Nov 2016 11:00:29 +0100 From: Goswin von Brederlow To: "Richard W.M. Jones" Cc: caml-list@inria.fr Message-ID: <20161108100029.GB18517@frosties> References: <20161107132201.GG27249@annexia.org> <20161107154843.GH27249@annexia.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161107154843.GH27249@annexia.org> User-Agent: Mutt/1.6.0 (2016-04-01) X-Provags-ID: V03:K0:/SrQ2cOaSS2lfRrhHo/nHv6dWCwk7xRSAxoZImd8NByaZUGOHOB wXtZVfwsBRWlBrhtNvGWEqFLhE6VjeBk7HoIH7ixq7yRDm0mSzshvokp1I4BnQtfiFwqmiP +c8T1X2reizyNur+XPvd23BQeUAJRR+QvXM4NQUVCRy7J38vqbCwwSIc2TFVVJAH6bhC2lM ZjiK4sFwA+EKFaOGwFRug== X-UI-Out-Filterresults: notjunk:1;V01:K0:DHZqCdW4w2A=:OqpO+X3eu9dTLZYLrgaQBr EtTWHVN2eMbgXyO6GP/XRz6ZYdr2+PeIu9nInqL0qD+9By0mxILqQbH9ILSA9C18BDv4hC25D oDxZyd/sjL0dox3wbKgDX+g9EBp9uINMNRlc8MyIRikpQ5fFVPxzL8IqcvAYqi1qCvs35dc2T PmM1UQRyMZlVnbKVpx8kGlo1EcDu/P1bagvNriBZC5pzhqjsxbmyWWfg4qOOVAbk+JOtFsO0b x9OTYcNZE2nIRdN3ouJlHN53hfIT/V6SJ4l8HyhUVWI2uBEpLKIfw0X+VjRJnuhi1vyqQc/3c 8NoBKy1ZciHB87EdLloLb1hSW0ATbN1uaQ21Meyfjanohe5N7IPXXHzVccWum7YLYNsTMkZEx V7/iHfKo2INddkcragd4Xd+58UFnuIgxiqVtZAgBSuubo69ceUyoBiha4/dovBhu4g8DpddA5 hxW0Pke2gSNW080nm6X1fg+tTykr61XNpnf7XDN5OMMl6aR9d78DwY6ZT/hrESe1DYfMLlLoa NXG+lQLqRwv9WUtaipoq9J4jHrRJOOfCzb8hL/suwv9qx9yVPn2zXYNfZAow0GdbgxmV8xh17 3D8w/1MkhPc6XGu+h9M5hu4MWzDV7S9+m1lj940gfjEZk7+Cfgf2GrOyMQb/UiIFXTyn3boJj InfJA0jQwI4fILAZaVKfXa5NQMr/mK+plArPEJHbb3eb3Lj/7dNoXN6GmTrWsGi3zd67Cirs/ QkoftrMfmHlKGmTFdwSColF+5G5f1XcoPj/Ag/ZKUeuPtvRY2JaFUyjPFY4= Subject: Re: [Caml-list] Zarith problems on ppc64le On Mon, Nov 07, 2016 at 03:48:43PM +0000, Richard W.M. Jones wrote: > On Mon, Nov 07, 2016 at 01:22:01PM +0000, Richard W.M. Jones wrote: > > > > https://bugzilla.redhat.com/show_bug.cgi?id=1392247 > > > > Zarith fails tests on OCaml 4.04.0 + ppc64le with some fairly gross > > errors, eg: > > > > of_float -1. > > - = -1 > > + = 0 > > > > (It passes fine on OCaml 4.04.0 + ppc64) > > > > The implementation of Zarith is quite complex and I've so far failed > > to understand what's going on. > > FWIW this seems like it is invoking undefined behaviour in C. See > my analysis here: > > https://bugzilla.redhat.com/show_bug.cgi?id=1392247#c3 > > Rich. What I don't get is why this ihappens only on ppc64le. For it to consistently return 0 there has to be some check in there for negative values. But that check is only present in some specialized ppc64le code? Seems like something the generic code for all archs should already have. Just out of interest: So what's so special about ppc64le that checking for negatives is present just there? MfG Goswin