Write an assembly language program that calculates the sum of all even numbers from 1 to N
Statement
Write an assembly language program that calculates the sum of all even numbers from 1 to N, where N is the largest digit of your VUID. Use jumps and labels to implement the necessary loops and conditionals. Store the final sum in a variable named sum.
Requirements:
- Calculate the sum of all even numbers from 1 to N, where N is the largest digit of your VUID.
- Use jumps and labels to implement loops and conditionals.
- Store the final sum in a variable named sum.
Solution:
section .data
VUID db "M17123456" ; Example VUID
sum dw 0 ; Variable to store the sum
max_digit db 0 ; Variable to store the largest digit
section .text
global _start
_start:
; Find the largest digit in VUID
mov ecx, 8 ; Loop counter (length of VUID)
mov esi, VUID ; Pointer to the VUID string
movzx eax, byte [esi] ; Load the first digit
mov max_digit, al ; Store it as the initial largest digit
; Loop to find the largest digit
find_largest_digit:
inc esi ; Move to the next digit
movzx eax, byte [esi] ; Load the digit
cmp al, max_digit ; Compare with the current largest digit
jle continue_loop ; If less than or equal, continue the loop
mov max_digit, al ; Update the largest digit
continue_loop:
loop find_largest_digit
; Calculate the sum of even numbers from 1 to N
mov cx, max_digit ; Initialize loop counter with the largest digit
mov bx, 1 ; Initialize the current number
mov ax, 0 ; Initialize the sum
calculate_sum:
test bx, 1 ; Check if the number is even
jnz next_number ; If not even, skip to the next number
add ax, bx ; Add the even number to the sum
next_number:
inc bx ; Increment the current number
loop calculate_sum
; Store the final sum in the sum variable
mov [sum], ax
; Exit the program
mov eax, 1 ; Exit syscall number
xor ebx, ebx ; Exit status
int 0x80 ; Call the kernel
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