anchor.diff:             (let* ((src-interval (interval-at allocator src instruction-index))
                     (dst-interval (interval-at allocator dst instruction-index))
                     (first-active-range (first (allocator-active-ranges allocator)))
  -                  (first-remaining-range (first (allocator-remaining-ranges allocator))))
  +                  (first-remaining-range (next-remaining-range allocator)))
                (and (not (interval-spilled-p allocator src-interval))
                     (eql first-active-range src-interval)
                     (eql (live-range-end first-active-range) instruction-index)
  
positive.code:                   (format t "remaining ~:S~%" (allocator-remaining-ranges allocator)))
                  (activate-interval allocator new-range reg))
                ;; Shouldn't be any remaining ranges coming live on this instruction.
                (assert (or (endp (allocator-remaining-ranges allocator))
                            (not (eql (live-range-start (first (allocator-remaining-ranges allocator))) instruction-index)))))
               (t
                (update-active-intervals allocator inst instruction-index)))
         (allocate-instants allocator inst instruction-index))
  
negative.code:        (cond ((and (typep inst 'ir:move-instruction)
                     (mergable-move-instruction-p allocator inst instruction-index))
                (let* ((old-range (pop (allocator-active-ranges allocator)))
                       (new-range (vector-pop (allocator-remaining-ranges allocator)))
                       (reg (gethash old-range (allocator-range-allocations allocator))))
                  (assert (eql (live-range-start new-range) instruction-index))
                  (unless ir::*shut-up*
  