+(defun handle-nested-dynamic-extent-lvars (dx lvar)
+ (let ((uses (lvar-uses lvar)))
+ ;; DX value generators must end their blocks: see UPDATE-UVL-LIVE-SETS.
+ ;; Uses of mupltiple-use LVARs already end their blocks, so we just need
+ ;; to process uses of single-use LVARs.
+ (when (node-p uses)
+ (node-ends-block uses))
+ ;; If this LVAR's USE is good for DX, it is either a CAST, or it
+ ;; must be a regular combination whose arguments are potentially DX as well.
+ (flet ((recurse (use)
+ (etypecase use
+ (cast
+ (handle-nested-dynamic-extent-lvars dx (cast-value use)))
+ (combination
+ (loop for arg in (combination-args use)
+ ;; deleted args show up as NIL here
+ when (and arg (lvar-good-for-dx-p arg dx))
+ append (handle-nested-dynamic-extent-lvars dx arg)))
+ (ref
+ (let* ((other (trivial-lambda-var-ref-lvar use)))
+ (unless (eq other lvar)
+ (handle-nested-dynamic-extent-lvars dx other)))))))
+ (cons lvar
+ (if (listp uses)
+ (loop for use in uses
+ when (use-good-for-dx-p use dx)
+ nconc (recurse use))
+ (when (use-good-for-dx-p uses dx)
+ (recurse uses)))))))
+