global _start
_start:

section .text
%macro dispmsg 2
mov rax,1
mov rdi,1
mov rsi, %1
mov rdx, %2
syscall
%endmacro

%macro accept 2
mov rax,0
mov rdi,0
mov rsi, %1
mov rdx, %2
syscall
%endmacro

dispmsg msg1,len1
accept num, 03
call convert
mov [no1],al

dispmsg msg2,len2
accept num, 03
call convert
mov [no2],al

;shift & add
mov ax,[no1]
mov bx,[no2]
mov cx,0000H
mov [res],cx

a1:
shr bx,01
jnc a2
add[res],ax

a2:
shl ax,01
cmp ax,00
jz a3
cmp bx,00
jnz a1

a3:
dispmsg msg3,len3
mov rax,[res]
call display

mov rax, 60
mov rdi,0
syscall


convert:
mov rsi,num
mov al,[rsi]
cmp al,39H
jbe l3
sub al,07H

l3:
sub al,30H
rol al,04
mov bl,al
inc rsi
mov al,[rsi]
cmp al,39H
jbe l4
sub al,07H

l4:
sub al,30H
add al,bl
ret

display:
mov rsi,disparr+15
mov rcx,16

l2: mov rdx,0
mov rbx,10h
div rbx
cmp dl,09h
jbe l1
add dl,07h

l1: add dl,30h
mov [rsi],dl
dec rsi
dec rcx
jnz l2

mov rax,1
mov rdi,1
mov rsi,disparr
mov rdx,16
syscall
ret

section .data
msg1 db "Enter a number 1:",0ah
len1 equ $-msg1

msg2 db "Enter a number 2 : ",0ah
len2 equ $-msg2

msg3 db "Multiplication using successive addition : ",0ah
len3 equ $-msg3


section .bss
disparr resb 40
res resb 40
no1 resb 40
no2 resb 40
num resb 40