From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from terminus.zytor.com (terminus.zytor.com [198.137.202.10]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 77938B7C06 for ; Tue, 16 Feb 2010 10:13:25 +1100 (EST) Message-ID: <4B79C775.1050903@zytor.com> Date: Mon, 15 Feb 2010 14:15:17 -0800 From: "H. Peter Anvin" MIME-Version: 1.0 To: Benjamin Herrenschmidt Subject: Re: register long sp asm("r1") incorrect References: <20100209152444.GA30176@atrey.karlin.mff.cuni.cz> <1265866273.16346.34.camel@pasglop> <20100215073405.GB20456@atrey.karlin.mff.cuni.cz> <1266263992.16346.125.camel@pasglop> <20100215202854.GA21601@elf.ucw.cz> <1266267898.16346.135.camel@pasglop> In-Reply-To: <1266267898.16346.135.camel@pasglop> Content-Type: text/plain; charset=UTF-8 Cc: kernel list , linuxppc-dev@ozlabs.org, paulus@samba.org, Pavel Machek List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 02/15/2010 01:04 PM, Benjamin Herrenschmidt wrote: > > It's true that most other use of it we have are global scope (local_paca > in r13, glibc use of r2/r13, etc...) afaik, but since r1 itself is the > stack pointer always, I think they pretty much guarantee it works. > It should work, because r1, being the stack pointer, is already marked a reserved register in gcc. The reference Pavel is citing bascially states that gcc won't globally reserve the register, which is true, but it is already reserved anyway. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.