title: division as multiply and LUT ? / fast float division reciprocal
body: <p>Is it possible to make a reciprocal of float division in form 
  of look up table (such like 1/f -> 1*inv[f] ) ? How it could be done? 
  I think some and mask and shift should be appled to float to make 
  it a form of index? How would be it exectly?</p>