From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by sourceware.org (Postfix) with ESMTPS id D27823858D33 for ; Tue, 10 Jan 2023 18:23:47 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org D27823858D33 Authentication-Results: sourceware.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1673375027; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:mime-version:mime-version: content-type:content-type:in-reply-to:in-reply-to: references:references; bh=k84GIPyxFxPBkW7CdQUzv7hOq83ehrWA36tIw1bwdg4=; b=Z1ZI3mMdyr4RBoSh1gaCNXSymkhVce8ee4Ns+4rglbl2HjZhvWR2RBmeTcEgv8LF8qNkhW BB6uwrOHbirGwaxjX1qNxwTz1EqdpGhhWfGLenNaUCd6w70zG+gDe2WSW/FJ+j+sxXvSUJ wyNdlsEoV8Zr0WkrceMBQv3MRUkZ4o8= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-136-TK3ldpeXOpeQAJUUcmRKhw-1; Tue, 10 Jan 2023 13:23:31 -0500 X-MC-Unique: TK3ldpeXOpeQAJUUcmRKhw-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id AA19B180A308; Tue, 10 Jan 2023 18:23:30 +0000 (UTC) Received: from tucnak.zalov.cz (unknown [10.39.192.223]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 2E88D2166B2B; Tue, 10 Jan 2023 18:23:30 +0000 (UTC) Received: from tucnak.zalov.cz (localhost [127.0.0.1]) by tucnak.zalov.cz (8.17.1/8.17.1) with ESMTPS id 30AINQxe2777131 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Tue, 10 Jan 2023 19:23:26 +0100 Received: (from jakub@localhost) by tucnak.zalov.cz (8.17.1/8.17.1/Submit) id 30AINNfA2777130; Tue, 10 Jan 2023 19:23:23 +0100 Date: Tue, 10 Jan 2023 19:23:23 +0100 From: Jakub Jelinek To: Michael Meissner , Joseph Myers , Segher Boessenkool , "Kewen.Lin" , GCC Patches , David Edelsohn , Peter Bergner , Richard Biener , Richard Sandiford Subject: Re: [RFC/PATCH] Remove the workaround for _Float128 precision [PR107299] Message-ID: Reply-To: Jakub Jelinek References: <718677e7-614d-7977-312d-05a75e1fd5b4@linux.ibm.com> <20221221212407.GU25951@gate.crashing.org> MIME-Version: 1.0 In-Reply-To: X-Scanned-By: MIMEDefang 3.1 on 10.11.54.6 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Spam-Status: No, score=-3.4 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,KAM_MANYTO,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_NONE,TXREP 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 Mon, Jan 09, 2023 at 10:21:52PM -0500, Michael Meissner wrote: > I had the patches to change the precision to 128, and I just ran them. C and > C++ do not seem to be bothered by changing the precision to 128 (once I got it > to build, etc.). But Fortran on the other hand does actually use the precision > to differentiate between IBM extended double and IEEE 128-bit. In particular, > the following 3 tests fail when long double is IBM extended double: > > gfortran.dg/PR100914.f90 > gfortran.dg/c-interop/typecodes-array-float128.f90 > gfortran.dg/c-interop/typecodes-scalar-float128.f90 > > I tried adding code to use the old precisions for Fortran, but not for C/C++, > but it didn't seem to work. > > So while it might be possible to use a single 128 for the precision, it needs > more work and attention, particularly on the Fortran side. Can't be more than a few lines changed in the fortran FE. Yes, the FE needs to know if it is IBM extended double or IEEE 128-bit so that it can decide on the mangling - where to use the artificial kind 17 and where to use 16. But as long as it can figure that out, it doesn't need to rely on a particular precision. Jakub