anchor.diff:  (defmethod (setf basic-block) (new (instruction sicl-mir:instruction))
     (setf (basic-block (find-instruction-info instruction))
   	new))
  +
  +(defgeneric predecessors (object)
  +  (:method ((object sicl-mir:instruction))
  +    (sicl-mir:predecessors object)))
  +
  +(defgeneric (setf predecessors) (new-predecessors object)
  +  (:method (new-predecessors (object sicl-mir:instruction))
  +    (setf (sicl-mir:predecessors object) new-predecessors)))
   
   (defun successors (instruction)
     (sicl-mir:successors instruction))
  
positive.code:       (error "no instruction-info for instruction ~s" instruction))
      info))
  
  (defmethod predecessors ((instruction sicl-mir:instruction))
    (predecessors (find-instruction-info instruction)))
  
  (defmethod (setf predecessors) (new (instruction sicl-mir:instruction))
    (setf (predecessors (find-instruction-info instruction))
  	new))
  
  (defmethod owner ((instruction sicl-mir:instruction))
    (owner (find-instruction-info instruction)))
  
  
negative.code: (set-processor 'basic-blocks 'compute-basic-blocks)
  
  (add-dependencies 'basic-blocks
  		  '(instruction-ownership))
  
  ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  ;;;
  