%macro scall 4 ;macro to take input and output
mov rax,%1
mov rdi,%2
mov rsi,%3
mov rdx,%4
syscall
%endmacro
section .data
menu db 10d,13d," MENU For Multiplication"
db 10d,"1. Successive Addition"
lnmenu equ $-menu
m1 db 10d,13d,"Utkarsh Pandule 2121049 "
l1 equ $-m1
m2 db 10d,13d,"Enter First Number: "
l2 equ $-m2
m3 db 10d,13d,"Enter Second Number: "
l3 equ $-m3
m4 db 10d,13d,"Answer: "
l4 equ $-m4
nwline db 10d,13d
section .bss
choice resb 2
answer resb 20
num1 resb 20
num2 resb 20
temp resb 20
section .text
global _start
_start:
;**********************MAIN LOGIC****************************
main:
scall 1,1,m1,l1
scall 0,0,temp,17
call asciihextohex
mov qword[num1],rbx
scall 1,1,m2,l2
scall 0,0,temp,17
call asciihextohex
mov qword[num2],rbx
mov rbx,qword[num1]
mov rcx,qword[num2]
mov rax,0 ;rax to store answer
cmp rcx,0 ;check multiplication with 0 condition
je skip3
loop1:
add rax,rbx
loop loop1 ;auto-decrement rcx and jmp
skip3:
mov rbx,rax ;backup rax in rbx
scall 1,1,m3,l3
mov rax,rbx ;restore rax which has answer
call display ;display answer from rax register
mov rax,60
mov rdi,0
syscall
;******************PROCEDURES********************************
asciihextohex:
mov rsi,temp
mov rcx,16
mov rbx,0
mov rax,0
loop4: rol rbx,04
mov al,[rsi]
cmp al,39h
jbe skip1
sub al,07h
skip1: sub al,30h
add rbx,rax
inc rsi
dec rcx
jnz loop4
ret
display:
mov rsi,answer+15
mov rcx,16
loop5: mov rdx,0
mov rbx,16
div rbx
cmp dl,09h
jbe skip2
add dl,07h
skip2: add dl,30h
mov [rsi],dl
dec rsi
dec rcx
jnz loop5
scall 1,1,answer,16
ret
Write, Run & Share Assembly code online using OneCompiler's Assembly online compiler for free. It's one of the robust, feature-rich online compilers for Assembly language. Getting started with the OneCompiler's Assembly compiler is simple and pretty fast. The editor shows sample boilerplate code when you choose language as Assembly and start coding.
Assembly language(asm) is a low-level programming language, where the language instructions will be more similar to machine code instructions.
Every assembler may have it's own assembly language designed for a specific computers or an operating system.
Assembly language requires less execution time and memory. It is more helful for direct hardware manipulation, real-time critical applications. It is used in device drivers, low-level embedded systems etc.
Assembly language usually consists of three sections,
Data section
To initialize variables and constants, buffer size these values doesn't change at runtime.
bss section
To declare variables
text section
_start specifies the starting of this section where the actually code is written.
There are various define directives to allocate space for variables for both initialized and uninitialized data.
variable-name define-directive initial-value
| Define Directive | Description | Allocated Space |
|---|---|---|
| DB | Define Byte | 1 byte |
| DW | Define Word | 2 bytes |
| DD | Define Doubleword | 4 bytes |
| DQ | Define Quadword | 8 bytes |
| DT | Define Ten Bytes | 10 bytes |
| Define Directive | Description |
|---|---|
| RESB | Reserve a Byte |
| RESW | Reserve a Word |
| RESD | Reserve a Doubleword |
| RESQ | Reserve a Quadword |
| REST | Reserve a Ten Bytes |
Constants can be defined using
CONSTANT_NAME EQU regular-exp or value
%assign constant_name value
%define constant_name value
Loops are used to iterate a set of statements for a specific number of times.
mov ECX,n
L1:
;<loop body>
loop L1
where n specifies the no of times loops should iterate.
Procedure is a sub-routine which contains set of statements. Usually procedures are written when multiple calls are required to same set of statements which increases re-usuability and modularity.
procedure_name:
;procedure body
ret