From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 14993 invoked by alias); 15 Apr 2004 15:29:26 -0000 Mailing-List: contact gdb-patches-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sources.redhat.com Received: (qmail 14961 invoked from network); 15 Apr 2004 15:29:25 -0000 Received: from unknown (HELO localhost.redhat.com) (66.30.197.194) by sources.redhat.com with SMTP; 15 Apr 2004 15:29:25 -0000 Received: from gnu.org (localhost [127.0.0.1]) by localhost.redhat.com (Postfix) with ESMTP id 05D752B9C; Thu, 15 Apr 2004 11:29:16 -0400 (EDT) Message-ID: <407EAA4B.7000500@gnu.org> Date: Thu, 15 Apr 2004 15:29:00 -0000 From: Andrew Cagney User-Agent: Mozilla/5.0 (X11; U; NetBSD macppc; en-GB; rv:1.4.1) Gecko/20040217 MIME-Version: 1.0 To: Orjan Friberg Cc: Daniel Jacobowitz , gdb-patches@sources.redhat.com Subject: Re: Multiplexed registers and invalidating the register cache References: <407D242B.109@axis.com> <20040414144607.GA5700@nevyn.them.org> <407E67EA.80701@axis.com> <407E70FD.7060709@axis.com> In-Reply-To: <407E70FD.7060709@axis.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-SW-Source: 2004-04/txt/msg00311.txt.bz2 > Orjan Friberg wrote: > >> Daniel Jacobowitz wrote: >> >>> >>> I think you should make this change unconditionally - and flush the >>> entire frame cache. >> >> >> >> Pardon my ignorance, but why should the entire frame cache be flushed, instead of just invalidating the current set of registers? Is it because frame pointer/return address registers (or something else affecting other frames) might change? Consider the effect of modifying the $sp. While it might in theory be possible to implement some sort of complicated look-aside cache schema, in reality there is zero return on investment. Since recovery from the flush can't be slower than recovery from single-step, and single step is way way more critical, we should focus on single step. Andrew