anchor.diff:             (smash-r8)
              (load-constant :rcx (length (rest (arguments form))))
              (cond ((can-tail-call (rest (arguments form)))
  -                  (emit-tail-call (object-ea :rbx :slot 0) (first (arguments form))))
  +                  (emit-tail-call (object-ea :rbx :slot 0)))
                    (t (emit `(sys.lap-x86:call ,(object-ea :rbx :slot 0)))))
              (if (member *for-value* '(:multiple :tail))
                  (emit-gc-info :multiple-values 0)
  
positive.code:   (and (eql *for-value* :tail)
         (<= (length args) 5)))
  
  (defun emit-tail-call (where &optional what)
    (declare (ignorable what))
    #+nil(format t "Performing tail call to ~S in ~S~%"
            what (lambda-information-name *current-lambda*))
    (emit `(sys.lap-x86:leave)
          `(:gc :no-frame))
    (emit `(sys.lap-x86:jmp ,where)))
  
  (defun cg-variable (form)
  
negative.code:     (smash-r8)
      (load-constant :rcx (length (arguments form)))
      (cond ((can-tail-call (arguments form))
             (emit-tail-call (object-ea :r13 :slot sys.int::+fref-entry-point+))
             nil)
            (t (emit `(sys.lap-x86:call ,(object-ea :r13 :slot sys.int::+fref-entry-point+)))
               (if (member *for-value* '(:multiple :tail))
  