title: How conversion from int32 to int64 works
body: <p>My question is: How does the conversion from int32 to int64 work? I'm not interested in functions that do that, I'm interested in <strong>HOW</strong> they do that. What happens at the bit level?</p>
  
  <p>I'm particularly interested how negative int32 (ie. -23) is converted into int64.</p>