From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 22429 invoked by alias); 13 Jan 2005 20:33:45 -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 21970 invoked from network); 13 Jan 2005 20:33:28 -0000 Received: from unknown (HELO nexus.cs.usfca.edu) (138.202.170.4) by sourceware.org with SMTP; 13 Jan 2005 20:33:28 -0000 Received: by nexus.cs.usfca.edu (Postfix, from userid 203) id 1174721A3F; Thu, 13 Jan 2005 12:33:28 -0800 (PST) To: binutils@sources.redhat.com, cruse@cs.usfca.edu, hjl@lucon.org Subject: Re: Change i386 assembler/disassembler for SIB with INDEX==4 Cc: gcc@gcc.gnu.org, libc-alpha@sources.redhat.com, linux-kernel@vger.kernel.org Message-Id: <20050113203328.1174721A3F@nexus.cs.usfca.edu> Date: Thu, 13 Jan 2005 20:33:00 -0000 From: cruse@cs.usfca.edu (Allan B. Cruse) X-SW-Source: 2005-01/txt/msg00130.txt.bz2 On Thu, 13 Jan 2005, "H. J. Lu" wrote: > > > > Subject: Change i386 assembler/disassembler for SIB with INDEX==4 > > I am proposing to change i386 assembler/disassembler for SIB with > INDEX==4 > > http://sources.redhat.com/bugzilla/show_bug.cgi?id=658 > > It will change the assembler output for (%ebx,[1248]). I am not too > worried about the disassembler output since assembler can't generate > SIB with INDEX==4 directly today. Any comments? > > > H.J. > This change would give programmers the freedom to write instruction- syntax that the processor cannot actually execute, is that right? Perhaps the downside to this would lie in the hours of debugging and private research each programmer would then be faced with, trying to figure out why " movl (%esi,2),%eax " wasn't doing what he/she had intended, and which the assembler had dutifully accepted. --ABC