; File: arrayinc.asm
;
; A subroutine to be called from C programs.
; Parameters: int A[], int n
; Result: A[0], ... A[n-1] are each incremented by 1


        SECTION .text
        global arrayinc

arrayinc:
        push    ebp                     ; set up stack frame
        mov     ebp, esp

        ; registers ebx, esi and edi must be saved, if used
        push    ebx
        push    edi

        mov     edi, [ebp+8]            ; get address of A
        mov     ecx, [ebp+12]           ; get num of elts
        mov     ebx, 0                  ; initialize count 

for_loop:
        mov     eax, [edi+4*ebx]        ; get array element
        inc     eax                     ; add 1
        mov     [edi+4*ebx], eax        ; put it back
        inc     ebx                     ; update counter
        loop    for_loop

        pop     edi                     ; restore registers
        pop     ebx
        
        mov     esp, ebp                ; take down stack frame
        pop     ebp

        ret