anchor.diff:      nil
       nil
       nil
  -    nil
  -    nil
  +    (decode-movzx8)
  +    (decode-movzx16)
       nil ; B8
       nil
       nil
       nil
       nil
       nil
  -    nil
  -    nil
  +    (decode-movsx8)
  +    (decode-movsx16)
       (decode-eb-gb sys.lap-x86:xadd8) ; C0
       (decode-ev-gv sys.lap-x86:xadd16 sys.lap-x86:xadd32 sys.lap-x86:xadd64)
       nil
  
positive.code:            (make-instruction 'sys.lap-x86:cmpxchg8b
                               (decode-gpr64-or-mem r/m (rex-b info)))))
        (t nil))))
  
  (defun decode-mov+r-ib (context info)
    (let ((reg (ldb (byte 3 0) (getf info :opcode))))
  
negative.code:     (decode-ev-sw sys.lap-x86:movseg)
      (decode-gv-ev nil sys.lap-x86:lea32 sys.lap-x86:lea64)
      (decode-sw-ew sys.lap-x86:movseg)
      (decode-group-1a)
      (decode-xchg+r) ; 90
      (decode-xchg+r)
      (decode-xchg+r)
  