From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80]) by finch.gentoo.org (Postfix) with ESMTP id 839621381F3 for ; Mon, 13 May 2013 06:45:57 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 29CADE0A5F; Mon, 13 May 2013 06:45:49 +0000 (UTC) Received: from mail-we0-f170.google.com (mail-we0-f170.google.com [74.125.82.170]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id C9334E09E4 for ; Mon, 13 May 2013 06:45:47 +0000 (UTC) Received: by mail-we0-f170.google.com with SMTP id u54so6014757wes.29 for ; Sun, 12 May 2013 23:45:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=x-received:message-id:date:from:user-agent:mime-version:to:subject :references:in-reply-to:content-type:content-transfer-encoding; bh=+/AnCYQ3jROBqIgj67QZvocf2OgK7PgVRZQU8dTBAe4=; b=SV80cbJY4nLiw/g8nL3fGl0amBBVvqsMZU33xHpauJTyBuRMchEhA7LB6YuwtxKJIm 9KetTUYADi8rPKRc0veJhV6XUgSNQRpK1ATmT6GMXRJkXuE/W1/SO2WAOnaToxcFgkrJ 3jUdRGvme1LHOqiCuJ2kfoWDrpCtCm43nulvSaMZ+VHintRbOtG12Z7ktchfgdweh1zX JEphmWDpdt72evhLvajOX/XCMGs0T0YPD/ICf1tvioW4zkiVjXneum4NlDALQrogBmtq pq57qX3g7iAyrXoZ0raGsK27c8cnIxWmYM9TpHYFqB/mcwgRP0HiWqFMHukCK+ikrXYm iRbQ== X-Received: by 10.180.185.114 with SMTP id fb18mr16087840wic.33.1368427546483; Sun, 12 May 2013 23:45:46 -0700 (PDT) Received: from [10.1.196.113] (dustpuppy.is.co.za. [196.14.169.11]) by mx.google.com with ESMTPSA id g8sm14774056wiy.4.2013.05.12.23.45.44 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Sun, 12 May 2013 23:45:45 -0700 (PDT) Message-ID: <51908C07.3070602@gmail.com> Date: Mon, 13 May 2013 08:45:27 +0200 From: Alan McKinnon User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130413 Thunderbird/17.0.5 Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org MIME-Version: 1.0 To: gentoo-user@lists.gentoo.org Subject: Re: [gentoo-user] Gcc compiling, is this normal? References: <519006A0.2080807@gmail.com> <51900954.9050002@gmail.com> <20130512173736.5f6851c5@osage> In-Reply-To: <20130512173736.5f6851c5@osage> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Archives-Salt: 994e9b58-bb64-4ecf-b155-e855827c3595 X-Archives-Hash: be413c85ec7e6f7e5961bfc1bfcf4a18 On 12/05/2013 23:37, David Relson wrote: >> [1] The logic goes something like this: it's a compiler, so the code >> > it produces must be consistently identical for identical inputs. So, >> > the current compiler builds gcc, giving version Y built by version X. >> > That instance of gcc in turn builds a gcc, giving version Y built by >> > version Y. > Haven't you left out the third compile? > > Let me rephrase the 3 builds. > > 1) gcc-X builds gcc-Y giving gcc-Y1 > 2) gcc-Y1 builds gcc-Y giving gcc-Y2 > 3) gcc-Y2 builds gcc-Y giving gcc-Y3 > > gcc-Y1 and gcc-Y2 are likely to be different (since they were build by > gcc-X and gcc-Y which are likely to have optimizations). > > gcc-Y2 and gcc-Y3 should be identical (since both were built by gcc-Y) > >> > Yeah, I think you're right. Thanks for that. Like I said, I'm fuzzy on the details after all these years. My intention was not to be completely accurate and correct, it was more to get the general idea across to Dale -- Alan McKinnon alan.mckinnon@gmail.com