On Mar 13, 2007, at 8:53 AM, Brian Ginsbach wrote:

> /*
> * Exchange values in memory.  test_and_set is unconditional.
> * compare_and_swap is conditional, returning 1 and swapping if the
> * memory value equals "old".

Yah, that's basically what I'm doing.  I just don't want to be forced  
to return the old value if the swap does not occur, nor do I  
particularly want to return the old value at all (partially because it  
means more instructions in the inner-loop of most load-locked/store- 
conditional type systems).

-- thorpej