anchor.diff:          (dcval 0))
       (declare #.*optimize*
                (type fixnum tmp0 tmp1 tmp2 tmp3 tmp10 tmp11 tmp12 tmp13 z1 z2 z3 z4 z5 dcval)
  -             (type sint16-2d-array block *ws*)
  +             (type sint16-2d-array block)
                (dynamic-extent tmp0 tmp1 tmp2 tmp3 tmp10 tmp11 tmp12 tmp13 z1 z2 z3 z4 z5 dcval))
       (loop for dptr fixnum from 0 to 7 ; iterating over columns
             if (and (zerop (s16ref block dptr 1))
  
positive.code:     (declare #.*optimize* (type fixnum n))
      (aref +csize+ (plus n 1023)))
  
  ;;; zigzag ordering
  (defun zigzag (buffer)
    (declare #.*optimize*
  	   (type sint16-2d-array buffer)
  	   (type sint16-array *zz-result*))
    (loop for row of-type sint16-array across buffer
       for z-row of-type uint8-array across +zigzag-index+ do
         (loop for x fixnum from 0 to 7 do
  
negative.code:     (declare #.*optimize*
               (type fixnum ncomp Hmax Vmax x-growth y-growth nwidth)
               (type (simple-array t (*)) freqs fr)
               (dynamic-extent fr freqs))
      (catch 'marker
        (loop
  