VIA PadLock support

[Alan Modra]

On Thu, Mar 11, 2004 at 04:08:10PM +0100, Michal Ludvig wrote:
> Hi all,
> this patch adds support for (dis)assembling VIA Nehemiah PadLock 
> instructions. These insns are 3 bytes long and except for 'xstore' must 
> have a 'rep' prefix. I modified add_prefix() to accept 'xcrypt' insns 
> both with and without explicitly mentioned 'rep' (although it is always 
> emitted exacly once without complains).

I think it would be better to warn if a rep prefix is given with these
instructions.  Also, do any of these instructions take a lock prefix?
Since rep and lock are mutually exclusive on other x86 archs, the
assembler warns if you use both.

Assuming lock isn't allowed,
 - then your changes aren't correct as you'll lose the lock warning.  
 - you could dipense with the add_prefix change, and instead check
   i.prefix[LOCKREP_PREFIX] in the following code before calling
   add_prefix.

> +      if (i.tm.cpu_flags & CpuPadLock) {
> +	if (i.tm.base_opcode & 0xff000000)
> +	  add_prefix ((i.tm.base_opcode >> 24) & 0xff, 1);
> +      }	else {
> +	if (i.tm.base_opcode & 0xff0000)
> +	  add_prefix ((i.tm.base_opcode >> 16) & 0xff, 0);
> +      }

Formatting here and elsewhere.  Braces go on separate lines.

-- 
Alan Modra
IBM OzLabs - Linux Technology Centre