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

rhyde@[EMAIL PROTECTED]
" asked:

[about seg reg size]

No Randy, there never were any requirement to tell a 'load seg-reg'
-instruction that a seg-reg can only hold 16 bits.

The opposite direction ie: "mov eax,es" does an Zx-extension on modern
CPUs while some oldies left the high word(upper 16 bits) undefined
or unaltered, but a  "push es |pop eax"  sequence  may just show
any previous stack contents in the highword of eax instead of Zero.

So neither 66 nor 67 prefix are required for load sreg, even some tools
may create them for museum-compatibility reasons, but Push/Pop
should be aware of it if not just used for save/restore seg-regs.
__
wolfgang
I expect Rene will be very happy to see you post again :)