From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ua1-x930.google.com (mail-ua1-x930.google.com [IPv6:2607:f8b0:4864:20::930]) by sourceware.org (Postfix) with ESMTPS id D2B833858415; Sat, 8 Jan 2022 19:15:25 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org D2B833858415 Received: by mail-ua1-x930.google.com with SMTP id o1so16362360uap.4; Sat, 08 Jan 2022 11:15:25 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to; bh=x5Hu9yiT72cQ8T/Pm98MwkQ8Xr065h/uj5eQvj9QnRs=; b=bTugEa1SPeAsjIAVI/Kaj+aICRPZBT1l3ITM4MxOLknaVC0c78EKiVK1u6P1wKUSrt epsdO16XUOqFxwyPUAK0/4sRQx/VkBYqqTfU1mrqDdIE3gZTCrtYHD+sYFWeoHd/S8o3 nVJiLE/FoF9oYga4pg/2lINY350XJJa1P33MUUNpCieyD6thVQWE9HfqxdBhcWZ/UDrz s4vjgib1qbe3WLov7tHh9B7HenLnxg4SMv5gTNYiQri0yNh127ZwztDB5rYLOO2VLIT/ TkQyE6r1F59AOX4rtWpZ9FL1k6iK/bP0JrMDbcSbxh261xUrODhV+lCRafl9HjrUT04w yg8Q== X-Gm-Message-State: AOAM531YTEnvFopxrE5yQ6IVYiPSJEu+jkcvPDN/RnjjhSN5/znKMvek XodFzfYfbLFk24RfCmqQ5CwxXKTMGnXLTx15Hug= X-Google-Smtp-Source: ABdhPJwmDmW++dGAN8ztHxaqY8CA05tL5x9RTG0ONpM7bz+pfDnZ5vaBRWQRDDQn1+BF22425IAHrqLDGb2+THMODKA= X-Received: by 2002:a67:e192:: with SMTP id e18mr794987vsl.85.1641669325334; Sat, 08 Jan 2022 11:15:25 -0800 (PST) MIME-Version: 1.0 References: <28f0a876-7281-936d-f727-cb7067c052f9@netcologne.de> <20220107195220.GP2646553@tucnak> <332da363-1c64-e1bf-a05a-d412c600f580@netcologne.de> <20220107214813.GR2646553@tucnak> <124cfb8a-e3d0-207c-8dcb-bdfab29372cb@netcologne.de> <20220108110038.GS2646553@tucnak> <20220108111056.GT2646553@tucnak> <20220108140258.GU2646553@tucnak> <8aff0c01-1715-aa06-5823-ed92567c1ea6@netcologne.de> <20220108141807.GV2646553@tucnak> In-Reply-To: From: David Edelsohn Date: Sat, 8 Jan 2022 14:15:14 -0500 Message-ID: Subject: Re: [power-ieee128] OPEN CONV To: Michael Meissner , Jakub Jelinek , Thomas Koenig , Segher Boessenkool , "fortran@gcc.gnu.org" , Peter Bergner , Bill Schmidt , GCC Patches , David Edelsohn Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-0.7 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, FREEMAIL_FROM, KAM_MANYTO, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: fortran@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Fortran mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 08 Jan 2022 19:15:27 -0000 On Sat, Jan 8, 2022 at 1:59 PM Michael Meissner wrote: > > On Sat, Jan 08, 2022 at 03:18:07PM +0100, Jakub Jelinek wrote: > > On Sat, Jan 08, 2022 at 03:13:10PM +0100, Thomas Koenig wrote: > > > > > > On 08.01.22 15:02, Jakub Jelinek via Fortran wrote: > > > > Note, as for byteswapping, apparently it wasn't ever working right fox > > > > the IBM extended real(kind=16) and complex(kind=16). > > > > > > The lack of bug reports since the conversion feature was introduced in > > > 2006, more than 15 years ago, tells us something, I guess... > > > > powerpc64le was only introduced in GCC 4.8 in 2013, so slightly less > > than that, but still. > > Either nobody interchanges/shares fortran unformatted data between > > powerpc big and little endian, or if they do, they don't use real(kind=16) > > or complex(kind=16) in there... > > I still wish I had had the forethought when we were setting up the LE ABI to > change the default 128-bit format to IEEE instead of IBM. But alas, I didn't. > You would still need converters between the big endian IBM format and little > endian IEEE format, but it would have avoided a lot of the problems where GCC > assumes there is only one floating point format for each size. Mike, The LE ABI initial target was Power8 and IEEE128 hardware support was added to Power9. The ABI was a conscious decision. IEEE 128 was not a viable requirement for the LE ABI at the time of the transition. Thanks, David