Re: MMX and floating point insn suport for reversible debugging

[paawan oza <paawan1982@yahoo.com>]

Hi,

yes.
I guess, MMX support needs to be added here, 

case 0x0f06:
       break;
       /* MMX/SSE/SSE2/PNI support */
       /* XXX */ 

but before I would start adding floating point support.

I have 2 doubts:
-> in function record_arch_list_add_reg
we are doing:
rec->u.reg.val = (gdb_byte *) xmalloc (MAX_REGISTER_SIZE);
we are allocating 128 bytes.....
but I suppose only SSE extensions can fully utilize the memory...
for rest of the registers, are not we allocating more memory than required for record ?

-> SSE support is not there in linux krenel (ptrace), I also read in some piece of comments also.
but SSE support (PT_GETXMMREGS) is suported in openbsd.

with that sense do we need to add SSE/SSE2/SSE3/SSE4 
support in i386-tdep.c generically ?  (of coursse our first priority is to add floating point suport, but I am querying out of my curiousity)

Regards,
Oza.


--- On Thu, 5/7/09, Hui Zhu <teawater@gmail.com> wrote:

> From: Hui Zhu <teawater@gmail.com>
> Subject: Re: MMX and floating point insn suport for reversible debugging
> To: "paawan oza" <paawan1982@yahoo.com>
> Cc: "Thiago Jung Bauermann" <bauerman@br.ibm.com>, "gdb ml" <gdb@sourceware.org>, "Pedro Alves" <pedro@codesourcery.com>, "Marc Khouzam" <marc.khouzam@ericsson.com>, "Michael Snyder" <msnyder@vmware.com>, "Eli Zaretskii" <eliz@gnu.org>, "Mark Kettenis" <mark.kettenis@xs4all.nl>
> Date: Thursday, May 7, 2009, 8:24 AM
> On Thu, May 7, 2009 at 02:02, paawan
> oza <paawan1982@yahoo.com>
> wrote:
> >
> > Hi Hui,
> >
> > I have started understanding and working on point-1.
> > I have some questions. please let me know my
> understanding is correct ?
> >
> > 1) i386-tdep.c is the one which has been done for
> record-replay. which basically takes care of disassembling
> insns...
> > but I see some code regarding MMX and x87FPU already
> available.
> > may I know exactly, what support is missing ?
> >
> 
>     case 0x0f06:
>       break;
> 
>       /* MMX/SSE/SSE2/PNI support */
>       /* XXX */
> 
>     default:
> 
> Your mean is this part?
> 
> 
> And I suggest you can begin with float point insn
> first.  It doesn't
> record float point reg change.
> 
> 
> Thanks,
> Hui
>