Re: Any more graceful way to saturate adds?

In article
<e9aa9511-4087-485f-822d-6dad776bce9a@[EMAIL PROTECTED]
>,
	Jim Leonard  <spamtrap@[EMAIL PROTECTED]
> writes:
> I am working in 16-bit 808x assembler (yes, on an old 808x CPU) and
> adding two 8-bit numbers to each other and saturating the result.
> Here is the best I could come up with:
> 
> ; AL and DL have unsigned 8-bit values to add

And the result should be unsigned also I suppose. In that case you
only need to test for overflow. Unsigned overflow sets the carry
flag. Extend the carry flag to all ones (FFh) for overflow and
zero for the normal case. Then it goes something like this:

     add  dl,al     ; do byte size add
     sbb  dh,dh     ; carry -> FFh no carry -> 0
     or   dl,dh     ; saturate
;    xor  dh.dh     ; Want word size result???