You've asked the right question, and for those that think validation is as simpLe as "run it and see if it gets the right result", good start but instruction or

You've asked the right question, and for those that think validation is as simpLe as "run it and see if it gets the right result", good start but instruction ordering can be critical around multi thread aware data structures. Taking a fence out, or an atomic operation might give a big performance gain. Trouble is the structure may now go wrong 1% of the time.