Maximum ammount of local variables in cg shaders ?

Hello,

I have a few questions about local variables in cg shaders...

I read arb_fragment_program and arb_fragment_program2 specification which is
about the assembly side of things...

There seem to be about 64 temporarely registers available or so...

However so far it seems it's possible to use many more local variables in
cg/cgfx shaders ?

For now I wonder what will happen if there are for example 1000 local
variables in a shader all "active" at the same time ?

Is this possible ? If so how is it implemented ? Does the gpu have some kind
of stack where excessive temporarely variables are pushed onto, and popped
off as needed ?

Or is there simply some kind of "temporarely variable limitation in cg
shaders" ?

So far I have already noticed one limitation: loop indexes only go to
4096...

Bye,
Skybuck.