+ (if live
+ (write-packed-bit-vector (compute-live-vars live node block var-locs vop)
+ *byte-buffer*)
+ (write-packed-bit-vector
+ (make-array (logandc2 (+ (hash-table-count var-locs) 7) 7)
+ :initial-element 0
+ :element-type 'bit)
+ *byte-buffer*))
+
+ (write-var-string (or (and (typep node 'combination)
+ (combination-step-info node))
+ "")
+ *byte-buffer*)