From owner-freebsd-current Mon Dec 11 17:42:32 2000 From owner-freebsd-current@FreeBSD.ORG Mon Dec 11 17:42:29 2000 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from hand.dotat.at (sfo-gw.covalent.net [207.44.198.62]) by hub.freebsd.org (Postfix) with ESMTP id 719D537B402 for ; Mon, 11 Dec 2000 17:42:29 -0800 (PST) Received: from fanf by hand.dotat.at with local (Exim 3.15 #3) id 145eSS-000Mmq-00; Tue, 12 Dec 2000 01:42:20 +0000 Date: Tue, 12 Dec 2000 01:42:20 +0000 From: Tony Finch To: Matt Dillon Cc: current@freebsd.org Subject: Re: RE: __asm help.. Message-ID: <20001212014220.E76746@hand.dotat.at> References: <200012082129.eB8LTMM22955@earth.backplane.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2i In-Reply-To: <200012082129.eB8LTMM22955@earth.backplane.com> Organization: Covalent Technologies, Inc Sender: fanf@dotat.at Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Matt Dillon wrote: >:As long as gcc uses %ebp to address local variables and functoin parameters >:rather than %esp you should be fine. %esp will be preserved, but if %esp is >:for some odd reason used to address a variable during the C code, you are hosed. > > I strongly recommend against making assumptions about GCC's use of %ebp vs > %esp... not if you want the __asm code to survive the GCC optimizer! But if gcc breaks that assumption, that implies it would break alloca(), and presumably they wouldn't do that. Tony. -- f.a.n.finch fanf@covalent.net dot@dotat.at "Dead! And yet there he stands!" To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message