(use-modules (system vm special-variable))
;; This makes sure to treat s special and not box it
(define (g x) 
  (let ((s 0)) 
    (mark-as-special s)  
    (let lp ((i 0)) 
      (if (< i 10000000) 
	  (begin (set! s (+ i s)) 
		 (lp (+ i 1))) 
	  s))))

#|
,x g

0    (assert-nargs-ee/locals 17)     ;; 1 arg, 2 locals
   2    (make-int8:0)                   ;; 0
   3    (local-set 1)                   ;; `s'
   5    (new-frame)                     
   6    (toplevel-ref 1)                ;; `((system vm special-variable) special #f)'
   8    (local-ref 1)                   ;; `s'
  10    (mv-call 1 :L583)               ;; MV -> 20
  15    (drop)                          
  16    (br :L584)                      ;; -> 23
  20    (truncate-values 0 0)           
  23    (br :L585)                      ;; -> 56
  27    (local-ref 2)                   ;; `i'
  29    (make-int16 3 232)              ;; 1000
  32    (lt?)                           
  33    (br-if-not :L586)               ;; -> 53
  37    (local-ref 2)                   ;; `i'
  39    (local-ref 1)                   ;; `s'
  41    (add)                           
  42    (local-set 1)                   ;; `s'
  44    (local-ref 2)                   ;; `i'
  46    (add1)                          
  47    (local-set 2)                   ;; `i'
  49    (br :L587)                      ;; -> 27
  53    (local-ref 1)                   ;; `s'
  55    (return)                        
  56    (make-int8:0)                   ;; 0
  57    (local-set 2)                   
  59    (br :L587)                      ;; -> 27

|#
;; This makes sure to treat s as special but we cannot box it because it's 
;; referenced in closure, set! + closure  = boxed
(define (g2 x) 
  (let ((s 0)) 
    (mark-as-special s)  
    (let lp ((i 0)) 
      (if (< i 10000000) 
	  (begin (set! s (+ i s)) 
		 (lp (+ i 1))) 
	  (lambda () s)))))


#|
0    (assert-nargs-ee/locals 17)     ;; 1 arg, 2 locals
   2    (make-int8:0)                   ;; 0                  at /home/stis/src/special.scm:45:2
   3    (box 1)                         
   5    (new-frame)                                           at /home/stis/src/special.scm:46:4
   6    (toplevel-ref 1)                ;; `((system vm special-variable) special #f)'
   8    (local-boxed-ref 1)             ;; `s'
  10    (mv-call 1 :L824)               ;; MV -> 20
  15    (drop)                          
  16    (br :L825)                      ;; -> 23
  20    (truncate-values 0 0)           
  23    (br :L826)                      ;; -> 67              at /home/stis/src/special.scm:47:4
  27    (local-ref 2)                   ;; `i'
  29    (make-uint64 0 0 0 0 0 152 150 128);; 10000000
  38    (lt?)                                                 at /home/stis/src/special.scm:48:10
  39    (br-if-not :L827)               ;; -> 59              at /home/stis/src/special.scm:48:6
  43    (local-ref 2)                   ;; `i'
  45    (local-boxed-ref 1)             ;; `s'
  47    (add)                                                 at /home/stis/src/special.scm:49:25
  48    (local-boxed-set 1)             ;; `s'                at /home/stis/src/special.scm:49:17
  50    (local-ref 2)                   ;; `i'
  52    (add1)                                                at /home/stis/src/special.scm:50:21
  53    (local-set 2)                   ;; `i'
  55    (br :L828)                      ;; -> 27              at /home/stis/src/special.scm:50:17
  59    (object-ref 2)                  ;; #<procedure 13bbe80 at /home/stis/src/special.scm:51:10 ()>
  61    (local-ref 1)                   ;; `s'
  63    (make-closure 0 1)              
  66    (return)                                              at /home/stis/src/special.scm:47:4
  67    (make-int8:0)                   ;; 0
  68    (local-set 2)                   
  70    (br :L828)                      ;; -> 27
|#