RE: PATCH: Move operand/address-size override prefixes before SIMD prefix

[malc <av1474 at comtv dot ru>]

On Thu, 7 Dec 2006, Jan Beulich wrote:

> > > > malc <av1474@comtv.ru> 07.12.06 13:34 >>>
> > On Thu, 7 Dec 2006, Dave Korn wrote:
> >
> > > On 07 December 2006 11:50, malc wrote:
> > >
> > >
> > > > So your position is that it's #UD. Objdump disagrees with you, whether
> > > > rightfully or not is an open question (or original question if you will)
> > >
> > >
> > >  Well, can't you just try single-stepping over one in the debugger and see if
> > > it executes something or blows up with an illegal instruction trap?
> >
> > I can. This will proove exactly nothing though. I want an official
> > position of Intel and AMD, even if the position is that the behaviour
> > is unspecified that will suit me just fine.
>
> It is undefined - the manuals say nothing about it being valid. And if 
> you tried this on hardware (I did a while ago), you'd see that it also 
> behaves like that (i.e. depending on count and order of prefixes you get 
> different results).

Thank you for the information.

--
vale