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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
> 


      


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