From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 887 invoked by alias); 17 Mar 2009 14:45:46 -0000 Received: (qmail 879 invoked by uid 22791); 17 Mar 2009 14:45:45 -0000 X-SWARE-Spam-Status: No, hits=1.6 required=5.0 tests=BAYES_50,DEAR_SOMETHING X-Spam-Check-By: sourceware.org Received: from mailserv.unb.ca (HELO mailserv.unb.ca) (131.202.1.21) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Tue, 17 Mar 2009 14:45:40 +0000 Received: from gollum.unb.ca (gollum.unb.ca [131.202.1.19]) by mailserv.unb.ca (8.13.6.20060614/8.13.6) with ESMTP id n2HEjWoa003326; Tue, 17 Mar 2009 11:45:33 -0300 Received: from localhost (localhost.localdomain [127.0.0.1]) by gollum.unb.ca (8.13.1/8.12.8) with ESMTP id n2HEjV5D001107; Tue, 17 Mar 2009 11:45:32 -0300 Received: from 198.164.100.100 ([198.164.100.100]) by webmail.unb.ca (IMP) with HTTP for ; Tue, 17 Mar 2009 11:45:31 -0300 Message-ID: <1237301131.49bfb78bd12ec@webmail.unb.ca> Date: Tue, 17 Mar 2009 14:45:00 -0000 From: "Wei, Wanxia" Reply-to: wanxia.wei@unb.ca To: gcc-help@gcc.gnu.org Subject: Ask for help MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit User-Agent: Internet Messaging Program (IMP) 3.2.2 Mailing-List: contact gcc-help-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-help-owner@gcc.gnu.org X-SW-Source: 2009-03/txt/msg00188.txt.bz2 Dear Sir/Madam: I am sorry I met a problem when I used gcc to compile my C program and ran the executables on servers. I compiled my C program with the following two different ways with different options. gcc -m32 -O3 -DNDEBUG -fno-strict-aliasing -static –lm gcc -m32 –O3 –lm My problem is that the two executables obtained by using the above two ways have the same performance on some inputs but have different performance on other inputs. I am sorry I do not know whether executables with different options should always have the same performance if the parameters are the same when executing these two executables. If two executables with different options should always have the same performance, the different performance of the two executables of my C program means there are bugs in this program? Thank you for your time and help. Yours sincerely, Wanxia Wei