casting int to uint and vice versa - performance

[Michal Minich]

What is performance overhead for casting value of type int to uint and in 
the opposite direction. What happen when I cast int to int or uint to uint 
(for the simplicity in generic code). I suppose there is no difference, 
and it is in fact no-op for processor - it depends only on 
interpretation. Only when making other operations compiler may generate 
different instruction when he considers some value of either of types. Am 
I right?

Thank you.