From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 24219 invoked by alias); 15 Apr 2004 10:46:42 -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 24198 invoked from network); 15 Apr 2004 10:46:40 -0000 Received: from unknown (HELO miranda.se.axis.com) (193.13.178.2) by sources.redhat.com with SMTP; 15 Apr 2004 10:46:40 -0000 Received: from axis.com (ironmaiden.se.axis.com [10.13.8.120]) by miranda.se.axis.com (8.12.9/8.12.9/Debian-5local0.1) with ESMTP id i3FAk2Um005268; Thu, 15 Apr 2004 12:46:02 +0200 Message-ID: <407E67EA.80701@axis.com> Date: Thu, 15 Apr 2004 10:46:00 -0000 From: Orjan Friberg Organization: Axis Communications User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6) Gecko/20040113 MIME-Version: 1.0 To: Daniel Jacobowitz CC: gdb-patches@sources.redhat.com Subject: Re: Multiplexed registers and invalidating the register cache References: <407D242B.109@axis.com> <20040414144607.GA5700@nevyn.them.org> In-Reply-To: <20040414144607.GA5700@nevyn.them.org> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-SW-Source: 2004-04/txt/msg00301.txt.bz2 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? > I'm not sure whether it should be in the generic > code that writes a register or the user-level code triggered by set > $reg = val, though. So either something like target_register_write (regno) where the target-specific code can do whatever it wants (presumably calling flush_cached_frames), or a more specialized function target_flush_register_cache_on_register_write (regno) and then have whatever calls that function do the actual frame cache flushing. > Andrew convinced me that the performance cost associated with this > would be small in practice. So, it's not worth the trouble implementing a more fine-grained solution like "refetch only the modified register". -- Orjan Friberg Axis Communications