From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 1525 invoked by alias); 30 Jan 2002 20:41:36 -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 1427 invoked from network); 30 Jan 2002 20:41:35 -0000 Received: from unknown (HELO lacrosse.corp.redhat.com) (12.107.208.154) by sources.redhat.com with SMTP; 30 Jan 2002 20:41:35 -0000 Received: from free.redhat.lsd.ic.unicamp.br (dhcpd143.meridian.redhat.com [172.16.47.143]) by lacrosse.corp.redhat.com (8.11.6/8.9.3) with ESMTP id g0UKfX331524; Wed, 30 Jan 2002 15:41:33 -0500 Received: (from aoliva@localhost) by free.redhat.lsd.ic.unicamp.br (8.11.6/8.11.6) id g0UKfOb10808; Wed, 30 Jan 2002 18:41:24 -0200 To: Greg McGary Cc: gcc@gcc.gnu.org Subject: Re: condition codes, haifa-sched and virtual-stack-vars References: <200201301859.g0UIxx606426@kayak.mcgary.org> From: Alexandre Oliva Organization: GCC Team, Red Hat Date: Wed, 30 Jan 2002 13:56:00 -0000 In-Reply-To: Greg McGary's message of "Wed, 30 Jan 2002 11:59:59 -0700" Message-ID: User-Agent: Gnus/5.0805 (Gnus v5.8.5) Emacs/20.7 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-SW-Source: 2002-01/txt/msg01944.txt.bz2 On Jan 30, 2002, Greg McGary wrote: > Haifa-sched schedules the move from virtual-stack-vars between the > bitfield test sequence and the branch. Later, global-reg alloc > instantiates virtual-stack-vars as an offset from FP, so the move > mutates into an add of fp+offset, clobbering the condition codes > computed earlier in the bitfield test. How about having a pre-reload move pattern that clobbers CC, split after reload into one that does not, so that sched2 could put the move between compare and branch should it indeed not affect CC? -- Alexandre Oliva Enjoy Guarana', see http://www.ic.unicamp.br/~oliva/ Red Hat GCC Developer aoliva@{cygnus.com, redhat.com} CS PhD student at IC-Unicamp oliva@{lsd.ic.unicamp.br, gnu.org} Free Software Evangelist *Please* write to mailing lists, not to me