From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 24935 invoked by alias); 17 Dec 2001 21:21:32 -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 24887 invoked from network); 17 Dec 2001 21:21:29 -0000 Received: from unknown (HELO igw3.watson.ibm.com) (198.81.209.18) by sources.redhat.com with SMTP; 17 Dec 2001 21:21:29 -0000 Received: from sp1n293en1.watson.ibm.com (sp1n293en1.watson.ibm.com [9.2.112.57]) by igw3.watson.ibm.com (8.11.4/8.11.4) with ESMTP id fBHLKvn28666; Mon, 17 Dec 2001 16:20:57 -0500 Received: from makai.watson.ibm.com (makai.watson.ibm.com [9.2.216.144]) by sp1n293en1.watson.ibm.com (8.11.4/8.11.4) with ESMTP id fBHLKvn22726; Mon, 17 Dec 2001 16:20:57 -0500 Received: from watson.ibm.com (localhost [127.0.0.1]) by makai.watson.ibm.com (AIX4.3/8.9.3/8.9.3/01-10-2000) with ESMTP id QAA22932; Mon, 17 Dec 2001 16:20:57 -0500 Message-Id: <200112172120.QAA22932@makai.watson.ibm.com> To: degger@fhm.edu cc: gcc@gcc.gnu.org Subject: Re: rs6000: Trivial code generation stupidity In-Reply-To: Message from degger@fhm.edu of "Mon, 17 Dec 2001 19:44:55 +0100." <20011217195138.8D51E6C3A@Nicole.fhm.edu> Date: Mon, 17 Dec 2001 13:21:00 -0000 From: David Edelsohn X-SW-Source: 2001-12/txt/msg00938.txt.bz2 >>>>> degger writes: degger> Is there anything that can be done about it? Gcc 3.1 (or what it is now) degger> generates quite good code for me at the moment except for in some really degger> obvious cases (like the ones mentioned) and thus it would be a shame to degger> give away some performance by those nasties. Also, you can look at the output from intermediate passes and see where gcc-2.95 chose the output in the correct register while gcc-3.1 introduces the extra copies. Track down which phase in gcc-3.1 is not collapsing the register copies or why it is introducing register copies. David