title: difference between .IF and IF in assembly
body: <p>what is the difference of .IF and IF directive in assembly?
  in document for .IF :</p>
  
  <pre><code>.IF condition1 
        statements
     [[.ELSEIF condition2 
              statements]]
     [[.ELSE
              statements]]
        .ENDIF
  </code></pre>
  
  <p>and for IF :</p>
  
  <pre><code>IF expression1
        ifstatements
     [[ELSEIF expression2
              elseifstatements]]
     [[ELSE
              elsestatements]]
     ENDIF
  </code></pre>