From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <binutils-return-38269-listarch-binutils=sources.redhat.com@sources.redhat.com>
Received: (qmail 9664 invoked by alias); 25 Feb 2005 15:45:59 -0000
Mailing-List: contact binutils-help@sources.redhat.com; run by ezmlm
Precedence: bulk
List-Subscribe: <mailto:binutils-subscribe@sources.redhat.com>
List-Archive: <http://sources.redhat.com/ml/binutils/>
List-Post: <mailto:binutils@sources.redhat.com>
List-Help: <mailto:binutils-help@sources.redhat.com>, <http://sources.redhat.com/ml/#faqs>
Sender: binutils-owner@sources.redhat.com
Received: (qmail 9558 invoked from network); 25 Feb 2005 15:45:47 -0000
Received: from unknown (HELO pollux.ds.pg.gda.pl) (153.19.208.7)
  by sourceware.org with SMTP; 25 Feb 2005 15:45:47 -0000
Received: from localhost (localhost [127.0.0.1])
	by pollux.ds.pg.gda.pl (Postfix) with ESMTP
	id 9D45DE1D46; Fri, 25 Feb 2005 16:45:42 +0100 (CET)
Received: from pollux.ds.pg.gda.pl ([127.0.0.1])
 by localhost (pollux [127.0.0.1]) (amavisd-new, port 10024) with ESMTP
 id 22187-09; Fri, 25 Feb 2005 16:45:42 +0100 (CET)
Received: from piorun.ds.pg.gda.pl (piorun.ds.pg.gda.pl [153.19.208.8])
	by pollux.ds.pg.gda.pl (Postfix) with ESMTP
	id 63453E1D01; Fri, 25 Feb 2005 16:45:42 +0100 (CET)
Received: from blysk.ds.pg.gda.pl (macro@blysk.ds.pg.gda.pl [153.19.208.6])
	by piorun.ds.pg.gda.pl (8.13.1/8.13.1) with ESMTP id j1PFjjoL024895;
	Fri, 25 Feb 2005 16:45:45 +0100
Date: Fri, 25 Feb 2005 20:25:00 -0000
From: "Maciej W. Rozycki" <macro@linux-mips.org>
To: cgd@broadcom.com
Cc: rsandifo@redhat.com, binutils@sources.redhat.com
Subject: Re: [patch] MIPS: Fix synthesized doubleword transfers (ping)
In-Reply-To: <yov51xb539ng.fsf@xl-sj1-01.sj.broadcom.com>
Message-ID: <Pine.LNX.4.61L.0502251535500.9216@blysk.ds.pg.gda.pl>
References: <Pine.LNX.4.61L.0502242001360.23589@blysk.ds.pg.gda.pl>
 <87sm3lhdo1.fsf@firetop.home> <mailpost.1109279149.22995@news-sj1-1>
 <yov51xb539ng.fsf@xl-sj1-01.sj.broadcom.com>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
X-Virus-Status: Clean
X-SW-Source: 2005-02/txt/msg00641.txt.bz2

On Thu, 24 Feb 2005 cgd@broadcom.com wrote:

> > I suppose bad things could happen if you composed an aligned
> > address from an unaligned symbol and an unaligned offset,
> > but is that allowed?
> 
> yes, at least as far as the ISA is concerned.

 For any ISA actually -- that MIPS IV limitation on address bases and 
displacements was essentially a hoax -- AFAIK, no MIPS IV processor has 
implemented it (including the R8000) and it's been explicitly removed for 
the MIPS64 ISA.  Besides, it would have broken binary compatibility with 
MIPS II and MIPS III anyway.

 It was probably meant as a way to allow some address calculation 
optimisation, which has never actually happened.

  Maciej