From patchwork Sun Jul 15 21:49:06 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gerald Pfeifer X-Patchwork-Id: 171107 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from sourceware.org (server1.sourceware.org [209.132.180.131]) by ozlabs.org (Postfix) with SMTP id 9ADCD2C00BF for ; Mon, 16 Jul 2012 07:49:32 +1000 (EST) Comment: DKIM? See http://www.dkim.org DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; d=gcc.gnu.org; s=default; x=1342993774; h=Comment: DomainKey-Signature:Received:Received:Received:Received:Date: From:To:cc:Subject:In-Reply-To:Message-ID:References: MIME-Version:Content-Type:Mailing-List:Precedence:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:Sender: Delivered-To; bh=j3Ha4k+DbQDd7l30+E58z5+rXeE=; b=XtB5gALgOk85F0O 3kad8QykLNGDf5ECfqLOnxx+Zyxyukl4YgqNtMnzBmM2hJRL2otUEwCgtPjCu8Bu OO/YjZGRveEsunY19RdlhV1ov+U+KkqvrVMQDrNnJEvxh3gwZctfCm5/5aNckrkg jr2cwz5d+X43GzT9zVMA52Lh3I1w= Comment: DomainKeys? See http://antispam.yahoo.com/domainkeys DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=default; d=gcc.gnu.org; h=Received:Received:X-SWARE-Spam-Status:X-Spam-Check-By:Received:Received:Date:From:To:cc:Subject:In-Reply-To:Message-ID:References:MIME-Version:Content-Type:X-IsSubscribed:Mailing-List:Precedence:List-Id:List-Unsubscribe:List-Archive:List-Post:List-Help:Sender:Delivered-To; b=hGV3ioTQI/iCr5hEpgmxx7qYLGaIG++L5U6ETTsNu+bRwVRoqKxIpw+mfA2o3N m/GjTT3PJREgOonRj7XMhHOupGxpewVtytyks4igA2uNi4WsiWJik9TzCVOudKEJ raIDa9qdI42fQo73jIfamuv0Uo3wOSwZbnbJftkh1qngo=; Received: (qmail 6817 invoked by alias); 15 Jul 2012 21:49:28 -0000 Received: (qmail 6808 invoked by uid 22791); 15 Jul 2012 21:49:25 -0000 X-SWARE-Spam-Status: No, hits=-3.4 required=5.0 tests=BAYES_00, KHOP_THREADED X-Spam-Check-By: sourceware.org Received: from ainaz.pair.com (HELO ainaz.pair.com) (209.68.2.66) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Sun, 15 Jul 2012 21:49:13 +0000 Received: from ip-109-41-25-88.web.vodafone.de (ip-109-41-25-88.web.vodafone.de [109.41.25.88]) by ainaz.pair.com (Postfix) with ESMTPSA id 2D5633F40F; Sun, 15 Jul 2012 17:49:09 -0400 (EDT) Date: Sun, 15 Jul 2012 23:49:06 +0200 (CEST) From: Gerald Pfeifer To: "H.J. Lu" cc: Jan Hubicka , Richard Henderson , "H. Peter Anvin" , gcc-patches@gcc.gnu.org Subject: Re: PATCH: PR target/53383: Allow -mpreferred-stack-boundary=3 on x86-64 In-Reply-To: Message-ID: References: <20120520144738.GA2225@intel.com> <20120622171126.GA6827@kam.mff.cuni.cz> <20120622181559.GB14390@kam.mff.cuni.cz> MIME-Version: 1.0 X-IsSubscribed: yes Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Delivered-To: mailing list gcc-patches@gcc.gnu.org On Fri, 22 Jun 2012, H.J. Lu wrote: > I am not sure if news.html is the best place for this. news.html definitely is not a good place for this, cf. the comment in that file. ;-) > How about putting it in gcc-4.8/changes.html? Yes, that fits. > Does it look OK? Index: ./gcc-4.8/changes.html =================================================================== +
  • Allow -mpreferred-stack-boundary=3 for the x86-64 + architecture with SSE extensions disabled. Since x86-64 ABI require the...ABI requires + used in controlled environment where stack space is important limitation. is an important limitation + long double and __int128), leading to wrong results. You must build all ... And the header for the supersection was missing. All fixed with the patch below which I committed. Index: gcc-4.8/changes.html =================================================================== RCS file: /cvs/gcc/wwwdocs/htdocs/gcc-4.8/changes.html,v retrieving revision 1.4 diff -u -3 -p -r1.4 changes.html --- gcc-4.8/changes.html 2 Jul 2012 11:35:28 -0000 1.4 +++ gcc-4.8/changes.html 15 Jul 2012 21:23:19 -0000 @@ -63,22 +63,22 @@ more information about requirements to b

    Java (GCJ)

    --> -

    IA-32/x86-64

    • Allow -mpreferred-stack-boundary=3 for the x86-64 - architecture with SSE extensions disabled. Since x86-64 ABI require - 16 byte stack alignment, this is ABI incompatible and intended to be - used in controlled environment where stack space is important limitation. + architecture with SSE extensions disabled. Since the x86-64 ABI + requires 16 byte stack alignment, this is ABI incompatible and + intended to be used in controlled environments where stack space + is an important limitation. This option will lead to wrong code when functions compiled with 16 byte stack alignment (such as functions from a standard library) are called with misaligned stack. In this case, SSE instructions may lead to misaligned memory access traps. In addition, variable arguments will be handled incorrectly for 16 byte aligned objects (including x87 - long double and __int128), leading to wrong results. You must build all + long double and __int128), leading to + wrong results. You must build all modules with -mpreferred-stack-boundary=3, including any libraries. This includes the system libraries and startup modules.