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 [170.10.129.124]) by sourceware.org (Postfix) with ESMTPS id C613F3858C54 for ; Mon, 14 Nov 2022 14:35:59 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org C613F3858C54 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=1668436559; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=VaqGOwzMOEFTlCpdIbDpBDiIaRVl3BUedA+1EqowL9I=; b=ZyoymvIvo+/czhyFZY99Kd+r/EIiIcaQr+DsGV1CX8tV1vJZXTDxyZG//ocY7WL3yK7XY0 ubfjQA/hQ8E03U88jQke1ctUezRaoavC5zna2nyo2hd5WlCzejRpJDDrVjN7T3k6JPncXG TUJxNxt7DuYlMXUaTCyS4pVcWuIyBR8= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-547-0LulcexlOk2AWym6m2R1Tg-1; Mon, 14 Nov 2022 09:35:58 -0500 X-MC-Unique: 0LulcexlOk2AWym6m2R1Tg-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 D50F52A2AD74; Mon, 14 Nov 2022 14:35:57 +0000 (UTC) Received: from tucnak.zalov.cz (unknown [10.39.192.38]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 75F182166B2B; Mon, 14 Nov 2022 14:35:57 +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 2AEEZqmY2854659 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT); Mon, 14 Nov 2022 15:35:52 +0100 Received: (from jakub@localhost) by tucnak.zalov.cz (8.17.1/8.17.1/Submit) id 2AEEZpx32854658; Mon, 14 Nov 2022 15:35:51 +0100 Date: Mon, 14 Nov 2022 15:35:50 +0100 From: Jakub Jelinek To: Jeff Law Cc: Aldy Hernandez , "Joseph S. Myers" , GCC patches , Andrew MacLeod Subject: Re: [PATCH] [range-ops] Implement sqrt. Message-ID: Reply-To: Jakub Jelinek References: <20221113200553.440728-1-aldyh@redhat.com> <6909e534-616b-035d-47fd-705a4e9fa86e@gmail.com> MIME-Version: 1.0 In-Reply-To: <6909e534-616b-035d-47fd-705a4e9fa86e@gmail.com> 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=WINDOWS-1252 Content-Disposition: inline Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-3.9 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,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, Nov 14, 2022 at 07:30:18AM -0700, Jeff Law via Gcc-patches wrote: > To Jakub's concern.  I thought sqrt was treated like +-/* WRT accuracy > requirements by IEEE.   ie, for any input there is a well defined answer for > a confirming IEEE implementation.   In fact, getting to that .5ulp bound is > a significant amount of the  cost for a NR or Goldschmidt (or hybrid) > implementation if you've got a reasonable (say 12 or 14 bit) estimator and > high performance fmacs. That might be the case (except for the known libquadmath sqrtq case PR105101 which fortunately is not a builtin). But we'll need to ulps infrastructure for other functions anyway and it would be nice to write a short testcase first that will test sqrt{,f,l,f32,f64,f128} and can be easily adjusted to test other functions. I'll try to cook something up tomorrow. Jakub