title: How to store three small numbers into one double?
body: <p>I have <code>int A, B, C</code>. And <code>A</code> is in range <code>0-9999</code>, <code>B</code> is <code>0-99</code>, <code>C</code> is <code>0-99</code>.</p>
  
  <p>Because the function must return only one <code>double</code>, I think of putting them all into one number. Otherwise I need to call function three times.
  But I cannot write an efficient code to do this. This will be called millions times, so it should be quite effective, but no ASM.</p>
  
  <p>I need a function <code>double pack3int_to_double(int A, int B, int C) {}</code></p>