From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 1958 invoked by alias); 3 Dec 2015 11:53:52 -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 1948 invoked by uid 89); 3 Dec 2015 11:53:51 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-2.0 required=5.0 tests=AWL,BAYES_00,SPF_PASS,T_RP_MATCHES_RCVD autolearn=ham version=3.3.2 X-HELO: fencepost.gnu.org Received: from fencepost.gnu.org (HELO fencepost.gnu.org) (208.118.235.10) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES128-SHA encrypted) ESMTPS; Thu, 03 Dec 2015 11:53:50 +0000 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59580) by fencepost.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1a4SSJ-0003hG-VB for gcc-patches@gnu.org; Thu, 03 Dec 2015 06:53:48 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1a4SSE-00036p-G5 for gcc-patches@gnu.org; Thu, 03 Dec 2015 06:53:47 -0500 Received: from relay1.mentorg.com ([192.94.38.131]:33764) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1a4SSE-000360-AR for gcc-patches@gnu.org; Thu, 03 Dec 2015 06:53:42 -0500 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 1a4SSD-0002DD-9A from Tom_deVries@mentor.com ; Thu, 03 Dec 2015 03:53:41 -0800 Received: from [127.0.0.1] (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; Thu, 3 Dec 2015 11:53:38 +0000 Subject: Re: [PATCH, 4/16] Implement -foffload-alias To: Jakub Jelinek , Richard Biener References: <5640BD31.2060602@mentor.com> <5640C560.1000007@mentor.com> <20151111110034.GF5675@tucnak.redhat.com> CC: "gcc-patches@gnu.org" From: Tom de Vries Message-ID: <56602D3E.7020804@mentor.com> Date: Thu, 03 Dec 2015 11:53:00 -0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: <20151111110034.GF5675@tucnak.redhat.com> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit X-detected-operating-system: by eggs.gnu.org: Windows NT kernel [generic] [fuzzy] X-Received-From: 192.94.38.131 X-SW-Source: 2015-12/txt/msg00428.txt.bz2 On 11/11/15 12:00, Jakub Jelinek wrote: > On Wed, Nov 11, 2015 at 11:51:02AM +0100, Richard Biener wrote: >>> The option -foffload-alias=pointer instructs the compiler to assume that >>> objects references in an offload region do not alias. >>> >>> The option -foffload-alias=all instructs the compiler to make no >>> assumptions about aliasing in offload regions. >>> >>> The default value is -foffload-alias=none. >> >> I think global options for this is nonsense. Please follow what >> we do for #pragma GCC ivdep for example, thus allow the alias >> behavior to be specified per "region" (whatever makes sense here >> in the context of offloading). > > Yeah, completely agreed. I don't see why the offloaded region would be in > any way special, they are C/C++/Fortran code as any other. > What we can and should improve is teach IPA aliasing/points to analysis > about the way we lower the host vs. offloading region boundary, so that > if alias analysis on the caller of GOMP_target_ext/GOACC_parallel_keyed > determines something it can be used on the offloaded function side and vice > versa, but a switch like the above is just wrong. Filed the GOMP_target_ext bit as PR 68675 - Handle GOMP_target_ext optimally in ipa-pta. Thanks, - Tom