anchor.diff:            vcsw-total (vcsw-gc 0) tmp-vcsw-before-gc
             ivcsw-total (ivcsw-gc 0) tmp-ivcsw-before-gc
             (gc-count 0)
  +          (empty-papi-set-p (zerop (length (events-of event-set))))
             return-values)
         (declare (type (signed-byte #.(* 8 (foreign-type-size :long-long)))
                        real-nsec-total user-nsec-total)
  
positive.code:         (setq page-faults-total (- faults page-faults-total))
          (setq vcsw-total (- vcsw vcsw-total))
          (setq ivcsw-total (- ivcsw ivcsw-total)))
        ;; Aggregate measurements.
        (let ((hw-event-results
               (loop for event in (events-of event-set) and i from 0 collect
  
negative.code:            (setq tmp-real-nsec-before-gc (papi-get-real-nsec))
             (setq tmp-user-nsec-before-gc (papi-get-virt-nsec)))
            (:after
             (unless empty-papi-set-p
               (papi-accum handle gc-values))
             (incf real-nsec-gc
                   (- (papi-get-real-nsec) tmp-real-nsec-before-gc))
             (incf user-nsec-gc
  