From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pigeon.gentoo.org ([208.92.234.80] helo=lists.gentoo.org) by finch.gentoo.org with esmtp (Exim 4.60) (envelope-from ) id 1QcTOa-0004Pd-KW for garchives@archives.gentoo.org; Fri, 01 Jul 2011 02:23:52 +0000 Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id B58AE1C019; Fri, 1 Jul 2011 02:22:42 +0000 (UTC) Received: from oproxy4-pub.bluehost.com (oproxy4-pub.bluehost.com [69.89.21.11]) by pigeon.gentoo.org (Postfix) with SMTP id 5F78C1C019 for ; Fri, 1 Jul 2011 02:22:42 +0000 (UTC) Received: (qmail 988 invoked by uid 0); 1 Jul 2011 02:22:41 -0000 Received: from unknown (HELO box443.bluehost.com) (69.89.31.243) by cpoproxy1.bluehost.com with SMTP; 1 Jul 2011 02:22:41 -0000 Received: from c-66-41-30-59.hsd1.mn.comcast.net ([66.41.30.59] helo=crud.chemoelectric.org) by box443.bluehost.com with esmtpsa (TLSv1:AES256-SHA:256) (Exim 4.69) (envelope-from ) id 1QcTNR-0003YY-D3 for gentoo-amd64@lists.gentoo.org; Thu, 30 Jun 2011 20:22:41 -0600 Received: by crud.chemoelectric.org (Postfix, from userid 1501) id 20D971807CBB; Thu, 30 Jun 2011 21:22:39 -0500 (CDT) Date: Thu, 30 Jun 2011 21:22:39 -0500 From: Barry Schwartz To: gentoo-amd64@lists.gentoo.org Subject: Re: [gentoo-amd64] Re: GCC-4.5.2 Has Serious Problems Message-ID: <20110701022239.GA13184@crud> References: <20110630174530.9bcbcd47.frank.peters@comcast.net> <20110630210429.fbcd8904.frank.peters@comcast.net> Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-amd64@lists.gentoo.org Reply-to: gentoo-amd64@lists.gentoo.org MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20110630210429.fbcd8904.frank.peters@comcast.net> User-Agent: Mutt/1.5.21 (2010-09-15) Content-Transfer-Encoding: quoted-printable X-Identified-User: {1474:box443.bluehost.com:crudfact:crudfactory.com} {sentby:smtp auth 66.41.30.59 authed with crudfactory@crudfactory.com} X-Archives-Salt: X-Archives-Hash: 4f8ffbc75b3d853864201b060c81a2cc Frank Peters skribis: > A few days ago I posted about a possible problem with a floating > point test called the UCBTEST. After examining the source code > of this test, I see violations of aliasing rules throughout. > It's hard to efficiently manipulate variables without them. C is essentially a glorified assembly language for PDP-11, designed for bit-twiddling, which the original K&R book encouraged, and which this code is doing. So all is well, from my point of view. :) Fancy optimizations are not to be trusted on assembly code; never be afraid to turn them off. You probably don=E2=80=99t need them, anyway. :)