From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf1-f52.google.com (mail-lf1-f52.google.com [209.85.167.52]) by sourceware.org (Postfix) with ESMTPS id 75BCD38618D4 for ; Fri, 5 Feb 2021 23:47:11 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 75BCD38618D4 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=rtems.org Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=joel.sherrill@gmail.com Received: by mail-lf1-f52.google.com with SMTP id h7so12426384lfc.6 for ; Fri, 05 Feb 2021 15:47:11 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:reply-to :from:date:message-id:subject:to; bh=IH94Oyjk2c9CCHThdXhvlZcwm0zDgOec6pC0rCD8oII=; b=LWeq4CrBLYB9IWGLFhWKeHKTFVIz2NsX8UrjwYgO3OhA6J4CaU472kfnqLKSYax2cO 57RjeAUkp4Q549x/DsM1DweZ+/07/Wz8jYegTaD98nGf498fCnWjkr/kDzkcrON9VYzq FEhfIxkge7HtjjxofrMyaeLLR/gJ57NWA6TvVRUwInwQYjnKK54R3xnOo7YG4fIpLHGG gx8CSPUdCTzbB5JxsGhj24MN+ilGML7yPYfCt0IZqKkBQf3hJVozkSwgXYNlzP2tppG1 rynGJLTrLxJT/hwGsqO653JeDI86Ax2WoS5FoNZsS4WD7xPkk0bUizxQpmFX8zS+KhZU 9RIQ== X-Gm-Message-State: AOAM532nWdvhgtpvzE2w+LR9nYYYtpsWAQbYW2bKWXYFm1BxcAz2MTJO 7F15EAGWqeCXCPz5evwX7Fy7mX9caiQ= X-Google-Smtp-Source: ABdhPJxm1FGAFFK1dMC4z4mTHD3CjtL5UjMyMIC+9X0ijygVkKTxnxb0uDJGq1LD99pzB9ewuklVtw== X-Received: by 2002:a2e:97c3:: with SMTP id m3mr4041280ljj.286.1612568829981; Fri, 05 Feb 2021 15:47:09 -0800 (PST) Received: from mail-lf1-f49.google.com (mail-lf1-f49.google.com. [209.85.167.49]) by smtp.gmail.com with ESMTPSA id p19sm1183051ljn.75.2021.02.05.15.47.09 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 05 Feb 2021 15:47:09 -0800 (PST) Received: by mail-lf1-f49.google.com with SMTP id h12so12384306lfp.9 for ; Fri, 05 Feb 2021 15:47:09 -0800 (PST) X-Received: by 2002:a05:651c:1301:: with SMTP id u1mr4029301lja.463.1612568829328; Fri, 05 Feb 2021 15:47:09 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: Reply-To: joel@rtems.org From: Joel Sherrill Date: Fri, 5 Feb 2021 17:46:57 -0600 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: accuracy of mathematical functions To: Newlib X-Spam-Status: No, score=-3031.9 required=5.0 tests=BAYES_00, FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS, HTML_MESSAGE, KAM_DMARC_STATUS, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H2, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=no autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.29 X-BeenThere: newlib@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Newlib mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 05 Feb 2021 23:47:14 -0000 On Fri, Feb 5, 2021 at 5:01 PM Brian Inglis wrote: > On 2021-02-05 03:43, Paul Zimmermann wrote: > > I have updated my comparison with the newly released 2.33 version. > > No big difference with the previous version, except that I included > > the "long double" format (aka ldbl-96), which is not supported by Newlib. > > > > https://members.loria.fr/PZimmermann/papers/#accuracy > > Thanks for doing this work and making it available is greatly appreciated. > > While newlib is mainly targeted to smaller platforms, the Cygwin port math > library supports gcc __FLT64X_...__/__FLT128_...__ under > .../newlib-cygwin/winsup/cygwin/math/ and related includes. > Any thoughts on what's required to have long double support on the targets where long double != double? Someone was recently cleaning up the warnings from the RTEMS tests which check that the headers match POSIX's man page and I generated this list of architectures from the RTEMS tools and which have long double support in libm.a no aarch64-rtems6 yes arm-rtems6 yes bfin-rtems6 no i386-rtems6 yes lm32-rtems6 no m68k-rtems6 yes microblaze-rtems6 yes mips-rtems6 yes moxie-rtems6 yes nios2-rtems6 yes or1k-rtems6 yes powerpc-rtems6 no riscv-rtems6 yes sh-rtems6 no sparc64-rtems6 yes sparc-rtems6 yes v850-rtems6 no x86_64-rtems6 It probably is a decent GSoC project if upstream sources for long double on some of those architectures can be identified for potential incorporation. > > As you may already be aware, clang and gcc have added support for ARM > __FLT16/__fp16, AMD and Intel have added it to x86/amd64 as CVT16/FP16C > https://en.wikipedia.org/wiki/F16C, and more compiler and library support > are > likely to follow, as they are already used in graphics and GPGPU areas. > What would this require from newlib, if anything? He asks ignorantly. :) --joel > -- > Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada > > This email may be disturbing to some readers as it contains > too much technical detail. Reader discretion is advised. > [Data in binary units and prefixes, physical quantities in SI.] > > [Shame your CORE-Math proposal was rejected: desperately needed these > days, as > I've never been a math natural but often seemed more comfortable than > other > programmers doing related work. > Maybe have to comb the literature on reproducible builds, need for > verification > no backdoors or vulnerabilities have been introduced, and testing results > produced are identical across platforms; maybe comb Risks or contact PGN > for > math horror stories as references and justifications for resubmission.] >