Re: mov seg, reg/mov reg, seg and size prefix

On Mar 21, 2:38 am, Frank Kotler  <spamt...@[EMAIL PROTECTED]
> wrote:

>
> That's why we should *never* emit the useless, redundant, cache-filling
> override when segreg is the *destination*. This one really *is* "always
> 16 bits". Might as well emit a "nop". Again, it'd be a painless one to
> get wrong.

A quick follow-up.
If the do***entation claims that the H.O. bits of EAX are undefined
after "mov eax,ds" (as opposed to being zero or left unchanged), why
bother emitting the prefix?  There are other instructions in the x86
instruction where Intel does this.
hLater,
Randy Hyde