title: How instanceof is implemented inside JAVA?
body: <p>Now I'm writing an ORM Framework and very care about performance.</p>
  
  <p>In this Framework , I have to use <code>instanceof</code> and <code>Class.isAssignableFrom</code> to check type compability.</p>
  
  <p>So I have a little doubt about the performance of <code>instanceof</code> and <code>Class.isAssignableFrom</code></p>
  
  <p>How slow exactly it is?</p>