From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 21472 invoked by alias); 24 Feb 2014 21:27:25 -0000 Mailing-List: contact crossgcc-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: crossgcc-owner@sourceware.org Received: (qmail 21461 invoked by uid 89); 24 Feb 2014 21:27:24 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-0.4 required=5.0 tests=AWL,BAYES_20,FREEMAIL_FROM,RCVD_IN_DNSWL_NONE,RP_MATCHES_RCVD,SPF_HELO_PASS,SPF_PASS autolearn=ham version=3.3.2 X-HELO: plane.gmane.org Received: from plane.gmane.org (HELO plane.gmane.org) (80.91.229.3) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES256-SHA encrypted) ESMTPS; Mon, 24 Feb 2014 21:27:23 +0000 Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1WI33U-0002NY-IK for crossgcc@sourceware.org; Mon, 24 Feb 2014 22:27:16 +0100 Received: from dsl.comtrol.com ([64.122.56.22]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Mon, 24 Feb 2014 22:27:16 +0100 Received: from grant.b.edwards by dsl.comtrol.com with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Mon, 24 Feb 2014 22:27:16 +0100 To: crossgcc@sourceware.org From: Grant Edwards Subject: 32-bit host vs 64-bit host Date: Mon, 24 Feb 2014 21:27:00 -0000 Message-ID: User-Agent: slrn/1.0.1 (Linux) X-IsSubscribed: yes X-SW-Source: 2014-02/txt/msg00060.txt.bz2 Let's say I build two copies of the "same" toolchain: one on a 32-bit (i686) host and the other on a 64-bit (amd64) host: both are using the same configuration, same sources files, for the same target (e.g. ARM). Would you expect the two toolchains to produce identical code when given identical sources? Or are there certain optimizations or transformations that differ depend on the _host_ machine word-size or architecture? For example: for the past few years you've been building an embedded linux linux system for an ARM9 target using a 32-bit hosted toolchain. How much of a risk is there if you move development to a 64-bit host and rebuild your toolchains as 64-bit apps? [Yes, I know that if you have 32-bit compatibility libraries you can continue to use the existing 32-bit toolchain binaries.] -- Grant Edwards grant.b.edwards Yow! Make me look like at LINDA RONSTADT again!! gmail.com -- For unsubscribe information see http://sourceware.org/lists.html#faq