;; sum all elements in an array
;;  quad core running strip 4
;;   result  
;;           one core 142 instructions
;;           dual core 80 instructions
;;           quad core 58 instructions

;; s = 0
;; i = 0
;; while i < N
;;   a = b[i]
;;   s = s + a
;;   i = i + 1


.symbol

  stop  	0
  print1 	17
  print2 	18

  ;; register
  link  	15
  retval 	27
  ;;  global variable and constants
  N     	20   ;; size of input 
  aB    	200  ;; ads of array
  sum2  	300  ;; share var sum from p2
  sum3		301
  sum4		302 

;; r2 : s, r3 : i, r4 : N, r5 : a

.code 0

  cid r3
  eq r2 r3 #0
  jt r2 p1
  eq r2 r3 #1
  jt r2 p2
  eq r2 r3 #2
  jt r2 p3
  jmp p4

:p1		;; sum 0,4,..
  mv r3 #0  	;; i = 0
  jal link suma
  mv r1 r2
  trap print1
  sync
  ld r2 sum2
  add r1 r1 r2
  ld r2 sum3
  add r1 r1 r2
  ld r2 sum4
  add r1 r1 r2
  trap print1
  trap stop

:p2		;; sum 1,5,..
  mv r3 #1  	;; i = 1
  jal link suma
  mv r1 r2
  trap print2
  st r1 sum2
  sync
  trap stop

:p3		;; sum 2,6,..
  mv r3 #2  	;; i = 2
  jal link suma
  mv r1 r2
  trap print2
  st r1 sum3
  sync
  trap stop

:p4		;; sum 3,7,..
  mv r3 #3  	;; i = 3
  jal link suma
  mv r1 r2
  trap print2
  st r1 sum4
  sync
  trap stop

:suma		;; strip by 4
  mv r2 r0  	;; s = 0
  mv r4 #N
  mv r7 #aB  	;; &b[.]  
:while
  lt r6 r3 r4  	;; i < N
  jf r6 exit
  ld r5 +r3 r7
  add r2 r2 r5
  add r3 r3 #4
  jmp while
:exit
  ret link

.data 200
  1 2 3 4 5 6 7 8 9 10
  11 12 13 14 15 16 17 18 19 20

.end