(defmethod lap-prepass (backend-function (instruction ir:make-dx-typed-vector-instruction) uses defs)
  (setf (gethash instruction *prepass-data*)
        (allocate-stack-slots
         (1+ (ir:make-dx-typed-vector-size instruction))
         :aligned t
         :livep (eql (sys.int::specialized-array-definition-type
                      (ir:make-dx-typed-vector-type instruction))
                     't))))

(defmethod emit-lap (backend-function (instruction ir:make-dx-typed-vector-instruction) uses defs)
  (let* ((slots (gethash instruction *prepass-data*))
         (size (ir:make-dx-typed-vector-size instruction))
         (words (1+ size)))
    (when (oddp words)
      (incf words))
    ;; Initialize the header.
    (load-literal :x9 (logior (ash (ir:make-dx-typed-vector-size instruction)
                                   sys.int::+object-data-shift+)
                              (ash (sys.int::specialized-array-definition-tag
                                    (ir:make-dx-typed-vector-type instruction))
                                   sys.int::+object-type-shift+)))
    (emit-stack-store :x9 (+ slots words -1))
    ;; Generate pointer.
    (load-literal :x9  (+ (- (* (1+ (+ slots words -1)) 8)) sys.int::+tag-object+))
    (emit `(lap:add ,(ir:make-dx-typed-vector-result instruction) :x29 :x9))
    ;; Possibly zero fill.
    (when (ir:make-dx-typed-vector-zero-fill-p instruction)
      ;;;;;; What is emmited here?
      (emit  ))))