anchor.diff:  		      (t
   		       (translate-datum item)))))
   
  -(defun layout-basic-block (basic-block)
  +(defun layout-basic-block (basic-block static-environment)
     (destructuring-bind (first last owner) basic-block
       (declare (ignore owner))
       (append (loop for instruction = first
  
positive.code: 					 collect (gethash successor *tags*))))
  	      (if (= (length successors) 1)
  		  (list (translate-simple-instruction
  			 last input-vars output-vars nil)
  			`(go ,(gethash (first successors) *tags*)))
  		  (list (translate-branch-instruction
  			 last input-vars output-vars successor-tags)))))))
  
negative.code: 	  do (setf (gethash instruction *tags*) (gensym)))
      (let ((tagbody
  	     `(tagbody
  		 ,@(layout-basic-block first nil)
  		 ,@(loop for basic-block in rest
  			 collect (gethash (first basic-block) *tags*)
  			 append (layout-basic-block basic-block nil))))
  	  (owned-vars (compute-owned-variables initial-instruction)))
        `(lambda (&rest args)
  	 (block nil
  