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Re: MMX & Floating point insn suport for reversible debugging
- From: paawan oza <paawan1982 at yahoo dot com>
- To: Hui Zhu <teawater at gmail dot com>
- Cc: gdb ml <gdb at sourceware dot org>
- Date: Fri, 15 May 2009 07:16:19 -0700 (PDT)
- Subject: Re: MMX & Floating point insn suport for reversible debugging
Thank you for your inputs.
I will try to post question more clearly : )
my question was :
Do we need to record floating point flags (C0,C1,C2 and c3) along with floating point registers ?
Regards,
Oza.
--- On Thu, 5/14/09, Hui Zhu <teawater@gmail.com> wrote:
> From: Hui Zhu <teawater@gmail.com>
> Subject: Re: MMX & Floating point insn suport for reversible debugging
> To: "paawan oza" <paawan1982@yahoo.com>
> Cc: "gdb ml" <gdb@sourceware.org>
> Date: Thursday, May 14, 2009, 12:41 PM
> On Thu, May 14, 2009 at 00:44, paawan
> oza <paawan1982@yahoo.com>
> wrote:
> >
> > I have gone through i387-tdep.c.
> > and I have come up with following doubts.
> >
> > here I start adding floating point register
> support.
> > I think curerntly it records the memory
> >
> > so remaining thing for floating point is store
> > registers st0 to st7.
> >
> >
> >> > code to be added here...
> >> > /* floats */
> >> > /* It just record the memory change
> of
> >> instrcution. */
> >> > case 0xd8:
> >> > case 0xd9:
> >> > case 0xda:
> >> > case 0xdb:
> >> > case 0xdc:
> >> > case 0xdd:
> >> > case 0xde:
> >> > case 0xdf:
> >> >
> >> >
> > do we need to collect affect FPU flags !!
>
> If gdb can output and set this flags, you need to do it.
> And I suggest you post more clear information about your
> question that
> you know when you have question with it. It will make
> people reply
> you mail easyly, right? :)
>
> >
> > and another thing is ;
> > take floating point insn
> > opcode mnemnic desc
> > DE F9 FDIVP Divide ST(1) by ST(0),
> > store result in ST(1),
> and
> > pop the register
> stack.
> >
> > I do not think code is taking care of 2 bytes
> floating
> > instruction..
> > I suspoe ModR/M and SIB byte encoding is taken care
> > with respect to floating point.
>
> Why you can't put the code for "DE F9" in:
> >> > case 0xde:
>
>
> Thanks,
> Hui
>