From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 1579 invoked by alias); 3 Sep 2014 15:49:18 -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 1569 invoked by uid 89); 3 Sep 2014 15:49:17 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.9 required=5.0 tests=AWL,BAYES_00 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; Wed, 03 Sep 2014 15:49:17 +0000 Received: from nat-ies.mentorg.com ([192.94.31.2] helo=SVR-IES-FEM-02.mgc.mentorg.com) by relay1.mentorg.com with esmtp id 1XPCnz-0001Tz-FA from joseph_myers@mentor.com ; Wed, 03 Sep 2014 08:49:10 -0700 Received: from digraph.polyomino.org.uk (137.202.0.76) by SVR-IES-FEM-02.mgc.mentorg.com (137.202.0.106) with Microsoft SMTP Server id 14.2.247.3; Wed, 3 Sep 2014 16:48:43 +0100 Received: from jsm28 (helo=localhost) by digraph.polyomino.org.uk with local-esmtp (Exim 4.82) (envelope-from ) id 1XPCna-0004KB-Aj; Wed, 03 Sep 2014 15:48:42 +0000 Date: Wed, 03 Sep 2014 15:49:00 -0000 From: "Joseph S. Myers" To: "Maciej W. Rozycki" CC: Adhemerval Zanella , Subject: Re: [PATCH] PowerPC: Implement TARGET_ATOMIC_ASSIGN_EXPAND_FENV In-Reply-To: Message-ID: References: <53E28E53.2000009@linux.vnet.ibm.com> <53F38135.9070604@linux.vnet.ibm.com> <5406433B.3030703@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" X-SW-Source: 2014-09/txt/msg00248.txt.bz2 On Wed, 3 Sep 2014, Maciej W. Rozycki wrote: > (floating-point environment is of course unsupported for soft-float > targets and for the SPE FPU another change is required to implement > floating-point environment handling to complement one proposed here). Support for SPE will depend on the C library just as soft-float support will, because of the need to have trapping on exceptions other than "inexact" enabled in the processor at all times with the kernel then using the prctl settings to determine whether that trap is for emulation or to produce SIGFPE. (The relevant support is in glibc 2.19 for soft-float and e500, in the form of __atomic_feholdexcept, __atomic_feclearexcept and __atomic_feupdateenv functions. I intend to implement the GCC side - conditional on being configured for glibc 2.19 or later on the target, as specified with --with-glibc-version or detected by configure's examination of target headers - once the hard-float support is in GCC. I believe the support in question will be identical for soft-float and e500, since it will be calling libc functions instead of manipulating processor state.) -- Joseph S. Myers joseph@codesourcery.com