 section .data
    array db 11h,59h,33h,22h,44h 

    msg1 db 10,"ALP to find the largest number in an array",10
    msg1_len equ $ - msg1
    
    msg2 db 10,"The Array contains the elements : ",10
    msg2_len equ $ - msg2
    
    msg3 db 10,10, "The Largest number in the array is : ",10
    msg3_len equ $ - msg3

section .bss
    counter resb 1
    result resb 4
    
%macro write 2
    mov rax,1
    mov rdi,1
    mov rsi,%1
    mov rdx,%2
    syscall
%endmacro

section .text
    global _start
    
_start: 
        
        write msg1 , msg1_len
        write msg2 , msg2_len
        
        mov byte[counter],05
        mov rsi,array
next:   mov al,[rsi]
        push rsi
        call disp
        pop rsi
        inc rsi
        dec byte[counter]
        jnz next
        
        write msg3 , msg3_len
        
        mov byte[counter],05
        mov rsi, array
        mov al, 0        ; al is an 8 bit register , al stores max      
repeat: cmp al,[rsi]     ;cmp opr1 , opr2  : opr1 - opr2
        jg skip
        mov al,[rsi]
skip:   inc rsi
        dec byte[counter]
        Jnz repeat
    
        call disp

        mov rax,60
        mov rdi,1
        syscall

disp:
        mov bl,al ;store number in bl
        mov rdi, result ;point rdi to result variable
        mov cx,02 ;load count of rotation in cl
up1:
        rol bl,04 ;rotate number left by four bits
        mov al,bl ;move lower byte in dl
        and al,0fh ; get only LSB
        cmp al,09h ;compare with 39h
        jg add_37 ;if grater than 39h skip add 37
        add al,30h
        jmp skip1 ;else add 30
add_37: add al,37h
skip1:  mov [rdi],al ;store ascii code in result variable
        inc rdi ;point to next byte
        dec cx ;decrement the count of digits to display
        jnz up1 ;if not zero jump to repeat
        
        write result , 4
        
        ret

created 3 years ago

Assembly Online Compiler

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.

About Assembly

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.

Syntax help

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.

Variables

There are various define directives to allocate space for variables for both initialized and uninitialized data.

1. To allocate storage space to Initialized data

Syntax

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

2. To allocate storage space to un-initialized data

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

Constants can be defined using

1. equ

To define numeric constants

CONSTANT_NAME EQU regular-exp or value

2. %assign

To define numeric constants.

%assign constant_name value

3. %define

To define numeric or string constants.

%define constant_name value

Loops

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.

Procedures

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