{HEAD ~ The mask} generated from the most significant bits section of the pointer includes bits corresponding to various regions of {TAIL ~ the output mask} 
{ HEAD ~ The mask } generated from the most significant bits section of the pointer includes bits corresponding to various regions of { TAIL ~ the output mask }
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL