ASSEMBLY - how to do sum between two numbers(interval)

Question

Hey guys can you help? I dont know how to do sum between two numbers For example :

first number>1

second number>5

sum w

Answer 1

You can use conditional jump to do so. Below, there is a simple code snippet in which ebx contains current number to be added, ecx contains number of times loop will run (i.e, second_number - first_number +1). sum will be stored in eax.

mov eax,0               ; initialise sum with 0
mov ebx,dword[first_number]    ;initialise ebx with first_number
mov ecx,dword[second_number]  
sub ecx,dword[first_number]
inc ecx                 ; ecx content will be end_number - start_number + 1, now
calculation:            ; after calculation sum can be accessed from eax
        add eax,ebx     ; sum = sum + ebx content
        inc ebx         ; ebx = ebx + 1
        dec ecx         ; ecx = ecx - 1
        cmp ecx,0h      ; ecx == 0 ?
        jne calculation ; if not then once again go through calculation.