Assembly: Bubble Sort

Group needs help on below assignment:

Add a variable to the below bubble sort procedure that is set to 1 whenever a pair of values is exchanged within the inner loop. use the variable to exit the sort before its normal completion.
extras:
-place values into a table
-run with 50 numbers (random array possibly)
-run comparison drill

;---------------------------------------------------------------------------
BubbleSort PROC USES eax ecx esi'
pArray

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TR DWORD' ; ointer array
Count

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WORD ; rray size

;
'Sort an array of 32-bit signed integers in ascending
;order, using the bubble sort algorithm.
;Receives: pointer to array, array size
;Returns:nothing
;---------------------------------------------------------------------------

mov ecx,Count
dec ecx ; decrement count by 1

L1: push ecx ; save outer loop count
mov esi,pArray ; point to first value

L2: mov eax, [esi] ; get array value
cmp [esi+4],eax ; compare a pair of values
jge L3 ; if [esi] <= [edi], don't exch
xchg eax, [esi+4] ; exchange the pair
mov [esi], eax
L3: add esi, 4 ; move both pointers forward
loop L2 ; inner loop

pop ecx ; retrieve outer loop count
loop L1 ; else repeat outer loop

L4: ret
BubbleSort ENDP

 

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sorry about the mistake

first half of procedure is:


BubbleSort PROC USES eax ecx esi,
pArray

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TR DWORD', ; pointer array
Count

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WORD ; array size

 

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Code:

;---------------------------------------------------------------------------
BubbleSort PROC USES eax ebx ecx esi'
   pArray:PTR DWORD'                        ; pointer array
   Count: DWORD                             ; array size

;Sort an array of 32-bit signed integers in ascending
;order, using the bubble sort algorithm.
;Receives: pointer to array, array size
;Returns:nothing
;---------------------------------------------------------------------------

   mov ecx,Count
   dec ecx                                  ; decrement count by 1
 
   L1: push ecx                             ; save outer loop count
       mov esi,pArray                       ; point to first value
       mov ebx, 0			    ; init the exit var

   L2: mov eax, [esi]                       ; get array value
       cmp [esi+4],eax                      ; compare a pair of values
       jge L3                               ; if [esi]  <= [edi],  don't exch
       xchg eax, [esi+4]                    ; exchange the pair
       mov [esi], eax			    
       cmp ebx,1			    ; if ebx = 1, exit
       je L4

   L3: add esi, 4                           ; move both pointers forward
       loop L2                              ; inner loop

       pop ecx                              ; retrieve outer loop count
       loop L1                              ; else repeat outer loop

   L4: ret
   BubbleSort  ENDP

Here is one way to answer the first question, but is it a beginner course or is there a hidden trap I didn't saw? Anyway, I added a counter ebx that will stop the procedure as soon as one exchange will have been done. You can give it a name if you want (do as with Count). An optimised version will not use ebx : just delete the added lines and replace je L4 by jmp L4.
On more thing that could be done : in my modifications, you could replace je L4 by a jump to pop ecx. Just have a look on what it would do... However, I don't remember if it would be a BubbleSort anymore.

 

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Bub Help

It's a beginner course, nothing hidden. But I'm sure this will get us on our way. Thanks!