anchor.diff:  
   (define-reg-use (call attrs . args) general-register-count)
   
  -(define (varrec-value varrec)
  -  (varrec-attr (or (varrec-attr varrec 'origin) varrec) 'value))
  -
   (define-codegen (call attrs func . args)
     (let* ((new-frame-base in-frame-base))
       (dolist (arg (reverse args))
  
positive.code:       (varrec-attr-set! varrec 'mode mode)
        (set! index (1+ index)))))
  
  (define-codegen-sections (lambda attrs body)
    (let* ((label (gen-label)))
      (form-attr-set! form 'label label)
      (codegen-sections body out)
  
      (emit out ".text")
  
negative.code:     (assign-varrec-indices (attr-ref attrs 'closure) 'closure)
      (assign-varrec-indices (attr-ref attrs 'params) 'param)
  
      (when self-varrec
        (emit-comment out "~S" (car self-varrec))
        (unless (varrec-written? self-varrec)
          (varrec-attr-set! self-varrec 'mode 'self)))
  
      (emit-label out label)
      (emit-function-prologue out)
  