From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 22073 invoked by alias); 16 Feb 2011 07:07:46 -0000 Received: (qmail 22061 invoked by uid 22791); 16 Feb 2011 07:07:45 -0000 X-SWARE-Spam-Status: No, hits=-2.2 required=5.0 tests=AWL,BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,SPF_HELO_PASS,T_RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from smtp-out.google.com (HELO smtp-out.google.com) (74.125.121.67) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Wed, 16 Feb 2011 07:07:40 +0000 Received: from wpaz1.hot.corp.google.com (wpaz1.hot.corp.google.com [172.24.198.65]) by smtp-out.google.com with ESMTP id p1G77bHn008891 for ; Tue, 15 Feb 2011 23:07:37 -0800 Received: from iyj8 (iyj8.prod.google.com [10.241.51.72]) by wpaz1.hot.corp.google.com with ESMTP id p1G77ZCd023269 (version=TLSv1/SSLv3 cipher=RC4-SHA bits=128 verify=NOT) for ; Tue, 15 Feb 2011 23:07:36 -0800 Received: by iyj8 with SMTP id 8so973783iyj.26 for ; Tue, 15 Feb 2011 23:07:35 -0800 (PST) Received: by 10.42.219.137 with SMTP id hu9mr330991icb.363.1297840055389; Tue, 15 Feb 2011 23:07:35 -0800 (PST) Received: from coign.google.com (adsl-71-133-8-30.dsl.pltn13.pacbell.net [71.133.8.30]) by mx.google.com with ESMTPS id ca7sm3792620icb.0.2011.02.15.23.07.34 (version=TLSv1/SSLv3 cipher=OTHER); Tue, 15 Feb 2011 23:07:34 -0800 (PST) From: Ian Lance Taylor To: sankar chebolu Cc: gcc-help@gcc.gnu.org Subject: Re: Variant code generation References: <90570.60405.qm@web30708.mail.mud.yahoo.com> Date: Wed, 16 Feb 2011 08:53:00 -0000 In-Reply-To: <90570.60405.qm@web30708.mail.mud.yahoo.com> (sankar chebolu's message of "Tue, 15 Feb 2011 21:25:05 -0800 (PST)") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-System-Of-Record: true X-IsSubscribed: yes 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: 2011-02/txt/msg00226.txt.bz2 sankar chebolu writes: > Does GCC has any command line switches which generate variant code? > To be more precise, Does GCC has some switches which, if applied to certain input program, it is not necessary that they will generate exactly the same code everytime. GCC is generally intended to be deterministic, in the sense that if you run it twice with the same input and the same options, you should get precisely the same result. There are a few exceptions: there are a few places where GCC uses random numbers. For those places you can use the -frandom-seed option where deterministic output is important. See the description of that option for the cases where random numbers are used. Ian