RE: [PATCH] gdb/x86: handle stap probe arguments in xmm registers

["Metzger, Markus T" <markus.t.metzger@intel.com>]

Hello Andrew,

>> Also, we would need to cast untyped registers to some type for any operation
>like
>> adding stack offsets as in 8@1600(%rbx).  It is arguably cleaner as the type now
>> comes from a particular interpretation of the register's content rather than
>from
>> the register itself, but that's maybe hair-splitting.
>
>I don't know what you mean by hair-splitting in this case.  This seems
>to be the biggest drawback from this proposal, and for me, I think this
>would be a huge step backwards in user experience.

I was referring to a non-user-visible internal-only change where registers would be
untyped and the type would later be added as the register's content get interpreted.
In the 8@1600(%rbx) example this would look like:

  Operation: UNOP_CAST
    Operation: UNOP_IND
      Operation: UNOP_CAST
        Operation: BINOP_ADD
          Operation: OP_LONG
            Type: long
            Constant: 0x0000000000000640
          Operation: UNOP_CAST
            Operation: OP_REGISTER
              String: rbp
            Type: uint8_t *
        Type: uint64_t *
    Type: uint64_t


In the end, this is very similar to the UNOP_EXTRACT you are proposing.

Regards,
Markus.
Intel Deutschland GmbH
Registered Address: Am Campeon 10, 85579 Neubiberg, Germany
Tel: +49 89 99 8853-0, www.intel.de <http://www.intel.de>
Managing Directors: Christin Eisenschmid, Sharon Heck, Tiffany Doon Silva  
Chairperson of the Supervisory Board: Nicole Lau
Registered Office: Munich
Commercial Register: Amtsgericht Muenchen HRB 186928