From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 11654 invoked by alias); 12 Dec 2002 22:58:42 -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 11626 invoked from network); 12 Dec 2002 22:58:42 -0000 Received: from unknown (HELO mail.cdt.org) (206.112.85.61) by sources.redhat.com with SMTP; 12 Dec 2002 22:58:42 -0000 Received: from dberlin.org (h-69-3-5-6.mclnva23.covad.net [69.3.5.6]) by mail.cdt.org (Postfix) with ESMTP id CFB60490103; Thu, 12 Dec 2002 17:56:11 -0500 (EST) Received: from [192.168.1.102] (account dberlin HELO dberlin.org) by dberlin.org (CommuniGate Pro SMTP 4.0.2) with ESMTP-TLS id 1801567; Thu, 12 Dec 2002 17:58:40 -0500 Date: Thu, 12 Dec 2002 15:28:00 -0000 Subject: Re: possible gcse failure: not able to eliminate redundant loads Content-Type: text/plain; charset=US-ASCII; format=flowed Mime-Version: 1.0 (Apple Message framework v551) Cc: David Edelsohn , Dale Johannesen , "Sanjiv Kumar Gupta, Noida" , gcc@gcc.gnu.org To: Richard Henderson From: Daniel Berlin In-Reply-To: <20021212224213.GD28987@redhat.com> Message-Id: <3FC59349-0E25-11D7-8880-000393575BCC@dberlin.org> Content-Transfer-Encoding: 7bit X-SW-Source: 2002-12/txt/msg00682.txt.bz2 On Thursday, December 12, 2002, at 05:42 PM, Richard Henderson wrote: > On Thu, Dec 12, 2002 at 05:31:39PM -0500, David Edelsohn wrote: >> I do not believe that the code exists, or if the code exists it is >> disabled because it is broken in other ways, not alias.c. > > Yawn. > > int x; > void foo() > { > int i; > for (i = 0; i < 100; i++) > x += i; > } > > foo: > movl x, %eax > xorl %edx, %edx > .p2align 4,,15 > .L6: > addl %edx, %eax > incl %edx > cmpl $99, %edx > jle .L6 > movl %eax, x > ret > > And from the .loop dump file, > > Loop from 10 to 31: 6 real insns. > Continue at insn 23. > Hoisted regno 62 r/w from (mem/f:SI (symbol_ref:SI ("x")) [2 x+0 S4 > A32]) > > Believe me now? I remember someone saying that store motion should replace this, since it subsumes it. > > r~