From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 98767 invoked by alias); 13 Jun 2019 21:16:15 -0000 Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-owner@gcc.gnu.org Received: (qmail 98753 invoked by uid 89); 13 Jun 2019 21:16:15 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-2.6 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_NONE,SPF_PASS autolearn=ham version=3.3.1 spammy=H*i:sk:ri64l4t, H*f:sk:ri64l4t, HX-Languages-Length:741, sites X-HELO: relay1.mentorg.com Received: from relay1.mentorg.com (HELO relay1.mentorg.com) (192.94.38.131) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Thu, 13 Jun 2019 21:16:14 +0000 Received: from nat-ies.mentorg.com ([192.94.31.2] helo=svr-ies-mbx-01.mgc.mentorg.com) by relay1.mentorg.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-SHA384:256) id 1hbX4s-00022h-Pq from joseph_myers@mentor.com ; Thu, 13 Jun 2019 14:16:10 -0700 Received: from digraph.polyomino.org.uk (137.202.0.90) by svr-ies-mbx-01.mgc.mentorg.com (139.181.222.1) with Microsoft SMTP Server (TLS) id 15.0.1320.4; Thu, 13 Jun 2019 22:16:07 +0100 Received: from jsm28 (helo=localhost) by digraph.polyomino.org.uk with local-esmtp (Exim 4.90_1) (envelope-from ) id 1hbX4p-0007eq-19; Thu, 13 Jun 2019 21:16:07 +0000 Date: Thu, 13 Jun 2019 21:16:00 -0000 From: Joseph Myers To: Martin Jambor CC: Tejas Joshi , , Subject: Re: Expanding roundeven (Was: Re: About GSOC.) In-Reply-To: Message-ID: References: <20190530213839.GF31586@gate.crashing.org> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" X-SW-Source: 2019-06/txt/msg00140.txt.bz2 On Thu, 13 Jun 2019, Martin Jambor wrote: > architecture supports it. (and if IIUC, the intent is to use the 0 mode > from table 4-8 in > https://software.intel.com/sites/default/files/managed/39/c5/325462-sdm-vol-1-2abcd-3abcd.pdf > in instructions that take a rounding a mode to implement roundeven). Note that the rounding mode argument to roundss / roundsd should end up as 8, not 0, so that the inexact exception is not raised. (8 here is the existing ROUND_NO_EXC definition in GCC. A new definition will need adding alongside ROUND_FLOOR, ROUND_CEIL and ROUND_TRUNC to correspond to rounding to nearest with ties to even, evaluating to 0.) -- Joseph S. Myers joseph@codesourcery.com