From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 1648 invoked by alias); 7 Sep 2003 09:59:38 -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 1641 invoked from network); 7 Sep 2003 09:59:37 -0000 Received: from unknown (HELO atrey.karlin.mff.cuni.cz) (195.113.31.123) by sources.redhat.com with SMTP; 7 Sep 2003 09:59:37 -0000 Received: by atrey.karlin.mff.cuni.cz (Postfix, from userid 29025) id C54684C02C9; Sun, 7 Sep 2003 11:59:36 +0200 (CEST) Date: Sun, 07 Sep 2003 10:39:00 -0000 From: Zdenek Dvorak To: Jim Wilson Cc: gcc@gcc.gnu.org, rth@redhat.com Subject: Re: Redundant check for prologue_epilogue_contains in init_alias_analysis? Message-ID: <20030907095936.GA4527@atrey.karlin.mff.cuni.cz> References: <20030906170936.GA4648@atrey.karlin.mff.cuni.cz> <3F5A90DC.10603@tuliptree.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3F5A90DC.10603@tuliptree.org> User-Agent: Mutt/1.3.28i X-SW-Source: 2003-09/txt/msg00329.txt.bz2 Hello, > Zdenek Dvorak wrote: > >the following check in init_alias_analysis seems partially redundant, > >partially wrong to me: > > In many cases like this, the best answer is to look at the historical > info. We have 6 years of CVS and mailing list logs. It isn't hard to > find that the patch came from here > http://gcc.gnu.org/ml/gcc-patches/1999-08n/msg00048.html > and this message also explains why the patch is there. > > For those that don't click through, the answer is that the FP won't be > considered a constant base pointer if we process prologue/epilogue > insns. There are other ways to handle this problem without ignoring all > prologue/epilogue instructions. would then just forcing fp to be considered a constant base pointer unconditionally be a solution? Zdenek