From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 3637 invoked by alias); 30 Jun 2005 14:42:23 -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 3544 invoked by uid 22791); 30 Jun 2005 14:42:12 -0000 Received: from mail-out4.apple.com (HELO mail-out4.apple.com) (17.254.13.23) by sourceware.org (qpsmtpd/0.30-dev) with ESMTP; Thu, 30 Jun 2005 14:42:12 +0000 Received: from mailgate1.apple.com (a17-128-100-225.apple.com [17.128.100.225]) by mail-out4.apple.com (8.12.11/8.12.11) with ESMTP id j5UEfxQX019969 for ; Thu, 30 Jun 2005 07:41:59 -0700 (PDT) Received: from relay3.apple.com (relay3.apple.com) by mailgate1.apple.com (Content Technologies SMTPRS 4.3.17) with ESMTP id ; Thu, 30 Jun 2005 07:41:59 -0700 Received: from [17.219.196.159] ([17.219.196.159]) by relay3.apple.com (8.12.11/8.12.11) with ESMTP id j5UEfvZV012033; Thu, 30 Jun 2005 07:41:58 -0700 (PDT) In-Reply-To: <200506250206.23245.stevenb@suse.de> References: <91fc834a41b6161b507a2a714c7b867a@physics.uc.edu> <200506250206.23245.stevenb@suse.de> Mime-Version: 1.0 (Apple Message framework v730) Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed Message-Id: <4B4BAEC7-6348-4408-B415-F6B6788C7374@apple.com> Cc: gcc@gcc.gnu.org, Andrew Pinski Content-Transfer-Encoding: 7bit From: fjahanian Subject: Re: [RFH] - Less than optimal code compiling 252.eon -O2 for x86 Date: Thu, 30 Jun 2005 14:42:00 -0000 To: Steven Bosscher X-SW-Source: 2005-06/txt/msg01305.txt.bz2 On Jun 24, 2005, at 5:06 PM, Steven Bosscher wrote: > On Saturday 25 June 2005 01:48, fjahanian wrote: > >> On Jun 24, 2005, at 3:16 PM, Andrew Pinski wrote: >> >>> I wonder why combine can do the simplification though which is why >>> still >>> produce good code for the simple testcase: >>> void f1(double *d,float *f2) >>> { >>> *f2 = 0.0; >>> *d = 0.0; >>> } >>> >> >> It is hard to reproduce the simple test case, exhibiting the same >> problem (-O1 producing better code than -O2). Yes, small test cases >> move the desired simplification to other phases. >> > > It often helps if you know what function your poorer code is in. You > could e.g. try to make the .optimized dump of that function compilable > and see if the problem shows up there again. Then work your way down > to something small. Yes, I am planning to do this. My first question was though if the RTL generated by -O2, which does not get simplified, is correct and should be optimized in one of the rtl optimizers. If not, then focus shifts to tree optimizers. - Thanks ,fariborz > > Gr. > Steven > >