Assignment 4

;Lab Assignment 3: Write an X86/64 ALP to find the largest
;of given Byte/Word/Dword/64-bit numbers.

section .data
array db 11h, 55h, 33h, 22h,44h
msg1 db 10,13,"Largest no in an array is:"
len1 equ $-msg1

section .bss
cnt resb 1
result resb 16

section .text
global _start
_start:
mov byte[cnt],5
mov rsi,array
mov al,0
LP: cmp al,[rsi]
jg skip
xchg al ,[rsi]
skip: inc rsi
dec byte[cnt]
jnz LP

;display
	mov Rax,1
	mov Rdi,1
	mov Rsi,msg1
	mov Rdx,len1
	syscall

;display al

call display

;exit system call
	mov Rax ,60
	mov Rdi,0
	syscall


%macro dispmsg 2
	mov Rax,1
	mov Rdi,1
	mov rsi,%1
	mov rdx,%2
	syscall
%endmacro
display:
	mov rbx,rax                      ; store no in rbx
	mov rdi,result                   ;point rdi to result variable 
	mov cx,16                        ;load count of rotation in cl  

	up1: 
		rol rbx,04               ;rotate no of 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 greater 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 counter
		jnz up1                  ; if not zero jump to repeat
		dispmsg result,16        ;call to macro
ret