From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 9635 invoked by alias); 23 Apr 2003 10:59:17 -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 9535 invoked from network); 23 Apr 2003 10:59:14 -0000 Received: from unknown (HELO d12lmsgate-4.de.ibm.com) (194.196.100.237) by sources.redhat.com with SMTP; 23 Apr 2003 10:59:14 -0000 Received: from d12relay02.de.ibm.com (d12relay02.de.ibm.com [9.165.215.23]) by d12lmsgate-4.de.ibm.com (8.12.9/8.12.8) with ESMTP id h3NAx5DI032328; Wed, 23 Apr 2003 12:59:05 +0200 Received: from d12ml028.de.ibm.com (d12ml028_cs0 [9.165.223.24]) by d12relay02.de.ibm.com (8.12.8/NCO/VER6.5) with ESMTP id h3NAx4O1195256; Wed, 23 Apr 2003 12:59:04 +0200 Importance: Normal Sensitivity: Subject: Re: Profiling on S390 To: Richard Henderson Cc: Jan Hubicka , gcc@gcc.gnu.org, aj@suse.de Message-ID: From: "Ulrich Weigand" Date: Wed, 23 Apr 2003 12:19:00 -0000 MIME-Version: 1.0 Content-type: text/plain; charset=us-ascii X-SW-Source: 2003-04/txt/msg01140.txt.bz2 Richard Henderson wrote: >It could, but if you don't have add/load/store insns that don't >clobber CC, then you'll get in trouble with reload too. We can load/store without clobbering CC; while we don't have a general addition operation that does not clobber CC, we do have a load-address operation, which is all reload actually needs (if things are set up correctly). However, LA is a 31-bit addition and cannot be used to implement 32-bit or even 64-bit integer arithmetic. However, it is certainly true that the use of gen_add2_insn in reload is really broken as it doesn't care at all whether CC gets clobbered. It is only by setting things up so that reload actually never tries to use gen_add2_insn that things work out ... >This is all about a movstrsi or cmpstrsi pattern? Perhaps it >would be better to keep this as one unit until after reload? It's only about cmpstrsi. The idea behind exposing the loop early was to potentially benefit from loop unrolling ... Mit freundlichen Gruessen / Best Regards Ulrich Weigand -- Dr. Ulrich Weigand Linux for S/390 Design & Development IBM Deutschland Entwicklung GmbH, Schoenaicher Str. 220, 71032 Boeblingen Phone: +49-7031/16-3727 --- Email: Ulrich.Weigand@de.ibm.com