From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 72061 invoked by alias); 20 Oct 2015 22:30:16 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Received: (qmail 72045 invoked by uid 89); 20 Oct 2015 22:30:15 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.3 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_LOW,SPF_PASS autolearn=ham version=3.3.2 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; Tue, 20 Oct 2015 22:30:14 +0000 Received: from nat-ies.mentorg.com ([192.94.31.2] helo=SVR-IES-FEM-01.mgc.mentorg.com) by relay1.mentorg.com with esmtp id 1ZofQ2-0006RI-Nq from joseph_myers@mentor.com ; Tue, 20 Oct 2015 15:30:10 -0700 Received: from digraph.polyomino.org.uk (137.202.0.76) by SVR-IES-FEM-01.mgc.mentorg.com (137.202.0.104) with Microsoft SMTP Server id 14.3.224.2; Tue, 20 Oct 2015 23:30:09 +0100 Received: from jsm28 (helo=localhost) by digraph.polyomino.org.uk with local-esmtp (Exim 4.82) (envelope-from ) id 1ZofPz-0000ou-Sa; Tue, 20 Oct 2015 22:30:07 +0000 Date: Tue, 20 Oct 2015 22:55:00 -0000 From: Joseph Myers To: Eric Botcazou CC: Jeff Law , Subject: Re: [patch] Fix failure of ACATS c45503c at -O2 In-Reply-To: <1528671.mzKt47kMez@polaris> Message-ID: References: <1990513.tXxA4OvBVE@polaris> <56268F8A.1040707@redhat.com> <1528671.mzKt47kMez@polaris> User-Agent: Alpine 2.10 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" X-SW-Source: 2015-10/txt/msg01996.txt.bz2 On Wed, 21 Oct 2015, Eric Botcazou wrote: > > Isn't this a function of the language and in some cases isn't it > > implementation defined (true for C/C++ until C++11)? > > I don't think that C/C++ use FLOOR_MOD_EXPR, only Ada does AFAIK. In any > case, I don't see how this can be implementation-defined given: And, given that RTL semantics are as well-defined and target-independent as GENERIC / GIMPLE semantics here, a corollary is that the MMIX option -mknuthdiv is fundamentally ill-conceived (affecting as it does the semantics of RTL operations whose semantics are assumed by the rest of the compiler to be target-independent). -- Joseph S. Myers joseph@codesourcery.com