Joerg Beekmann writes:
 > Can anyone comment on how much work would be involved in
 > 1) Adding a new 32bit field to the object header
 > 2) Adding a new immediate type like integer, presumable by adding 
 > another tag bit.

What are you trying to do?

If you're trying to speed up object creation for a small frequently
used object then writing a custom primitive to quickly create the
object will be much easier. Squeak's general new primitive is very
slow.  The next release of Exupery going to compile custom new
primitives.

While just speeding up object creation will still be several times
slower than creating a immediate, it may be fast enough. With luck
such a scheme will mean that garbage collection ends up taking most of
the time in object creation heavy code.

Bryce