; THIS CODE HAS BEEN TESTED AND IS FULLY OPERATIONAL.

; Problem Statement: Write X86/64 ALP to count number of positive and negative numbers from the array.

; Code from Microprocessor (SPPU - Second Year - Computer Engineering - Content) repository on KSKA Git: https://git.kska.io/sppu-se-comp-content/Microprocessor/


; BEGINNING OF CODE
%macro print 2
mov rax,1     ; Standard output
mov rdi,1     ; Input write
mov rsi,%1    ; Display message address
mov rdx,%2    ; Message length
syscall       ; Interrupt for kernel in 64-bit
%endmacro

section .data

m1 db 10,"ALP to count positive and negative numbers from an array",10
l1 equ $-m1

m2 db 10,"The count of positive numbers is:",10
l2 equ $-m2

m3 db 10,"The count of negative numbers is:",10
l3 equ $-m3

;array dw 8132h,6879h,711Ah,3567h,4567h
;array dd 81328132h,12346879h,6735711Ah,34563567h,67894567h
array dq 81328132ABCDh,12346879AAAAh,6735711AFFFFh,34563567EEEEh,67894567DEFAh

newline db 10
pcnt db 00
ncnt db 00

section .bss
displaybuffer resb 2

section .text

global _start:
_start:

print m1,l1

mov rsi,array
mov rcx,05

up:
bt qword [rsi],63		  	; Check the most significant bit for negativity
jnc pnxt							  ; If not negative, jump to pnxt
inc byte[ncnt]  				; Increment negative count
jmp pskip							  ; Jump to pskip
pnxt: inc byte[pcnt]    ; Increment positive count
pskip: add rsi,8				; Move to next 8 bytes
loop up									; Loop until rcx becomes zero

print m2,l2
mov bl,[pcnt]
call display
print newline,1

print m3,l3
mov bl,[ncnt]
call display
print newline,1

mov rax,60
syscall

display:
  mov rdi,displaybuffer  ; Destination for displaying
  mov rcx,02             ; Display 2 characters
dloop:
  rol bl,04              ; Rotate left by 4 bits
  mov dl,bl              ; Move contents of bl to dl
  and dl,0fh             ; Mask out upper bits
  add dl,30h             ; Convert to ASCII
  cmp dl,39h             ; Compare if greater than '9'
  jbe skip               ; Jump if below or equal
  add dl,07h             ; Adjust for letters
skip:
  mov [rdi],dl           ; Store the character
  inc rdi                ; Move to next position
  loop dloop             ; Loop until rcx becomes zero
print displaybuffer,2    ; Print the display buffer
ret
; END OF CODE