> If the signal processing algorithm is appropriately scaled, then all of the
> multiplications can be treated as multiplications by a factor of two.  What
> does that sound like?  Full marks if you said "arithmetic shift left"! :)

If this were true, it would be quite a revolution for the field of
digital signal processing.  Why not take it a step further and say
that "If the signal processing algorithm is appropriately scaled, then
all of the multiplications can be treated as multiplications by a
factor of one", and you could eliminate the shifts, too.

Of course, to scale the signal appropriately in the first place, you
only need to multiply it by a suitable constant...
-- 
Andreas Gustafsson, gson@araneus.fi