From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 14248 invoked by alias); 5 Aug 2009 13:48:50 -0000 Received: (qmail 14238 invoked by uid 22791); 5 Aug 2009 13:48:48 -0000 X-SWARE-Spam-Status: No, hits=-1.8 required=5.0 tests=AWL,BAYES_00,RCVD_IN_SORBS_WEB X-Spam-Check-By: sourceware.org Received: from web112510.mail.gq1.yahoo.com (HELO web112510.mail.gq1.yahoo.com) (98.137.26.158) by sourceware.org (qpsmtpd/0.43rc1) with SMTP; Wed, 05 Aug 2009 13:48:39 +0000 Received: (qmail 37428 invoked by uid 60001); 5 Aug 2009 13:48:37 -0000 Message-ID: <161390.36664.qm@web112510.mail.gq1.yahoo.com> Received: from [123.238.26.108] by web112510.mail.gq1.yahoo.com via HTTP; Wed, 05 Aug 2009 06:48:36 PDT Date: Wed, 05 Aug 2009 13:48:00 -0000 From: paawan oza Subject: Re: final i386.floating.record.patch To: Michael Snyder Cc: Hui Zhu , "gdb-patches@sourceware.org" In-Reply-To: <4A78E14C.2070608@vmware.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org X-SW-Source: 2009-08/txt/msg00072.txt.bz2 Hi Hui and Michael, Sure, I will preserve it. I modify the code and preserve it. I will send you the updated patch soon. this modification does not affect the core functionality, but as you sugges= ted, we are debugger, and should revert all register back. thank you for your inputs. Regards, Oza. --- On Wed, 8/5/09, Michael Snyder wrote: > From: Michael Snyder > Subject: Re: final i386.floating.record.patch > To: "paawan oza" > Cc: "Hui Zhu" , "gdb-patches@sourceware.org" > Date: Wednesday, August 5, 2009, 7:03 AM > paawan oza wrote: > > Hi Hui, > >=20 > > please find my analysis as follows. > >=20 > > following are the registers which you may find it > different. > >=20 > > fstat > > ftag > > fiseg > > fioff > > foseg > > fooff > > fop > >=20 > > In my opinion, we do not need to record all these > registers. because these registers are purly depends on > instruction's execution status in FPU unit. > >=20 > >=20 > > for e.g. > > fop register stores te last opcode executed by x87 FPU > unit. > > fstat register may contain c0, c1, c2, c3 flag > status... > >=20 > > why we dont need to record, because even if we reply > the recod... > > Anyway these register are going to be change by FPU HW > unit based on any fp insn's nature and its execution. (next > insn which FPU is going to execute) > >=20 > > so it doesnt make much sense to store it, because even > if we restore it, FPU unit doesnt use them directly, but FPU > HW sets them after executing current fp insn. so anyway they > are going to reset as soon as FPU executes next insn. > >=20 > > but still if you feel that we must record those > registers because user might want to observe those > registers, then I can do that. > >=20 > > please let me know you opinion about it. >=20 > It may be that saving the registers is not purely > necessary, but > we are not just a simulator -- we are a debugger.=A0 The > user might > be confused if he steps backward and sees that the register > did not > change. >=20 > So I think we should preserve it and revert it. >=20 >=20