From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 14276 invoked by alias); 6 May 2005 14:59:59 -0000 Mailing-List: contact binutils-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: binutils-owner@sources.redhat.com Received: (qmail 14249 invoked from network); 6 May 2005 14:59:53 -0000 Received: from unknown (HELO mx1.suse.de) (195.135.220.2) by sourceware.org with SMTP; 6 May 2005 14:59:53 -0000 Received: from hermes.suse.de (hermes-ext.suse.de [195.135.221.8]) (using TLSv1 with cipher EDH-RSA-DES-CBC3-SHA (168/168 bits)) (No client certificate requested) by mx1.suse.de (Postfix) with ESMTP id 3897C160FC35; Fri, 6 May 2005 16:59:53 +0200 (CEST) From: Andreas Schwab To: "Dave Korn" Cc: "'Jan Beulich'" , Subject: Re: [PATCH] x86: suppress emission of zero displacements in memoryoperands References: X-Yow: I am deeply CONCERNED and I want something GOOD for BREAKFAST! Date: Fri, 06 May 2005 15:04:00 -0000 In-Reply-To: (Dave Korn's message of "Fri, 6 May 2005 15:48:48 +0100") Message-ID: User-Agent: Gnus/5.110003 (No Gnus v0.3) Emacs/22.0.50 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit X-SW-Source: 2005-05/txt/msg00268.txt.bz2 "Dave Korn" writes: > Well, yes, it's vital for the assembler to support branch optimisation, > because the programmer can't know in advance which branches will be in range > or not. But it's also in the case of hand-coded assembler that the coder is > *most* likely to want to specify an exact instruction sequence, Most of the time you want optimal assembler code. > because the coder knows things about the program that the assembler > doesn't, and it ought to be (at least) possible if not (IMO) the default > behaviour. What if the zero is written as `foo - bar', where foo and bar are local labels surrounding a region that may be empty? Surely you want to get optimal assembler code independent of the value of foo - bar. > Relaxing branches without the "--relax" option violates the 'least > surprise' principle. I disagree. Andreas. -- Andreas Schwab, SuSE Labs, schwab@suse.de SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5 "And now for something completely different."