From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 24507 invoked by alias); 17 May 2003 01:45:23 -0000 Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Archive: List-Post: List-Help: Sender: gcc-owner@gcc.gnu.org Received: (qmail 24461 invoked from network); 17 May 2003 01:45:22 -0000 Received: from unknown (HELO rwcrmhc51.attbi.com) (204.127.198.38) by sources.redhat.com with SMTP; 17 May 2003 01:45:22 -0000 Received: from lucon.org (12-234-88-5.client.attbi.com[12.234.88.5]) by attbi.com (rwcrmhc51) with ESMTP id <20030517014522051001v5ote>; Sat, 17 May 2003 01:45:22 +0000 Received: by lucon.org (Postfix, from userid 1000) id 0D9502C681; Fri, 16 May 2003 18:45:22 -0700 (PDT) Date: Sat, 17 May 2003 05:52:00 -0000 From: "H. J. Lu" To: Richard Henderson , Andreas Schwab , gcc@gcc.gnu.org Subject: Re: Does gcc violate the ia64 ABI? Message-ID: <20030516184522.A7603@lucon.org> References: <20030516144401.A4222@lucon.org> <20030516152508.A4885@lucon.org> <20030517004318.GA18262@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5.1i In-Reply-To: <20030517004318.GA18262@redhat.com>; from rth@redhat.com on Fri, May 16, 2003 at 05:43:18PM -0700 X-SW-Source: 2003-05/txt/msg01653.txt.bz2 On Fri, May 16, 2003 at 05:43:18PM -0700, Richard Henderson wrote: > On Fri, May 16, 2003 at 03:25:08PM -0700, H. J. Lu wrote: > > d. At procedure return, gp must be valid (for the returning prodecure). > > This allows the compiler to optimize calls known to be local (i.e., the > > exceptions to Rule 'c'). > > I was not aware of this clause. I'd have sworn it wasn't a part > of the ABI at one time... > > Indeed, if this clause is truely correct, then virtually all of > the tail-call possibilities on ia64 are invalid. Yes, statics > still can be done, but that's not nearly as frequent. Gcc can skip gp save/restore across a local call. Right now, gcc saves and restores gp across a local call. > > Can you find out when this got added to the ABI? > Sure. BTW, the current one is dated May, 2001. H.J.