I have yet to see a dive computer that can handle the following scenario:

9:00am At Sea Level, computer turned on.

12:00pm Arrive at lake at 8000'

1:00pm First dive at high altitude lake.

(Computer correctly "pre-loads" nitrogen loading for trip to altitude (doing proper calculations as treating the first dive as a "repetive dive".) Most computers "assume" that you have been at altitude for 24 hours and does the standard "altitude profile".)