From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 10819 invoked by alias); 19 Oct 2009 17:47:36 -0000 Received: (qmail 10809 invoked by uid 22791); 19 Oct 2009 17:47:35 -0000 X-SWARE-Spam-Status: No, hits=-2.6 required=5.0 tests=AWL,BAYES_00,SPF_HELO_PASS,SPF_PASS X-Spam-Check-By: sourceware.org Received: from smtp-out.google.com (HELO smtp-out.google.com) (216.239.45.13) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Mon, 19 Oct 2009 17:47:31 +0000 Received: from spaceape11.eur.corp.google.com (spaceape11.eur.corp.google.com [172.28.16.145]) by smtp-out.google.com with ESMTP id n9JHlRaK005330 for ; Mon, 19 Oct 2009 10:47:28 -0700 Received: from fg-out-1718.google.com (fgg16.prod.google.com [10.86.7.16]) by spaceape11.eur.corp.google.com with ESMTP id n9JHlPY0018054 for ; Mon, 19 Oct 2009 10:47:25 -0700 Received: by fg-out-1718.google.com with SMTP id 16so673381fgg.7 for ; Mon, 19 Oct 2009 10:47:24 -0700 (PDT) Received: by 10.86.227.1 with SMTP id z1mr3171697fgg.56.1255974444886; Mon, 19 Oct 2009 10:47:24 -0700 (PDT) Received: from coign.google.com (adsl-71-133-8-30.dsl.pltn13.pacbell.net [71.133.8.30]) by mx.google.com with ESMTPS id e3sm7280fga.9.2009.10.19.10.47.21 (version=TLSv1/SSLv3 cipher=RC4-MD5); Mon, 19 Oct 2009 10:47:23 -0700 (PDT) To: "H.J. Lu" Cc: Michael Matz , Richard Guenther , Uros Bizjak , gcc-patches@gcc.gnu.org, Jakub Jelinek Subject: Re: PATCH: PR target/40838: gcc shouldn't assume that the stack is aligned References: <20090806214216.GA14439@lucon.org> <6dc9ffc80910171229u38ddfbf2m8ce1e2a9faa0745a@mail.gmail.com> <84fc9c000910171235p6f23ba3at22436dad2c4a22ca@mail.gmail.com> <6dc9ffc80910171246v19b116eby6ae6b01803e3affa@mail.gmail.com> <84fc9c000910171301xd87370eyada33fd9ae1bfd75@mail.gmail.com> <6dc9ffc80910190936j5d629f1fw1e2a83b96492b3fc@mail.gmail.com> <6dc9ffc80910191016k10a25518h7af44bb7903cc1fb@mail.gmail.com> <6dc9ffc80910191045u5bae5dcfl85e80cabca77ed9e@mail.gmail.com> From: Ian Lance Taylor Date: Mon, 19 Oct 2009 17:55:00 -0000 In-Reply-To: <6dc9ffc80910191045u5bae5dcfl85e80cabca77ed9e@mail.gmail.com> (H. J. Lu's message of "Mon\, 19 Oct 2009 10\:45\:11 -0700") Message-ID: User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-System-Of-Record: true X-IsSubscribed: yes 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 X-SW-Source: 2009-10/txt/msg01231.txt.bz2 "H.J. Lu" writes: >> If somebody asked you "where does gcc set the required stack >> alignment?" would you expect the answer to be "in the vectorizer >> code?" > > Yes, vectorizer may put requirement on stack alignment. But it is up > to backend to decide and it isn't the only place gcc may require > certain stack alignment. It's the only place your patch changes. >> Is there any way we can fix incoming stack alignment so that it can be >> controlled by automatic stack variables? =C2=A0I don't understand why th= is > > The incoming stack alignment can be controlled by automatic stack > variables. But it can't be controlled by pseudo registers. > >> is not done by the prologue and epilogue code. >> > > Because the prologue and epilogue code is generated after > RTL expansion starts? That just restates my question without answering it. Ian