Question

Using Windows 32 framework , write an assembly language program;

Write a recursive procedure to find the greatest common divisor of
two non negative numbers. You should use Euclidean algorithm and this is typically
discussed in CSC 230. Your procedure:
❼ Needs to follow cdecl protocol.
❼ Needs to take two parameters.
❼ Should return -1, if the parameters are negative.
❼ Should return gcd, if the parameters are non negative.
Your main procedure should do the followings.
❼ Read two integers using input macro.
❼ Call above gcd procedure after appropriately passing parameters.
❼ Display an appropriate message using output macro if procedure returns -1 or
❼ Display the valid result returned from your procedure using the output macro.
Euclid Algorithm:
         gcd(m, 0) = m
         gcd(m, n) = gcd(n, m mod n)

Answer 1

1). ANSWER :

GIVENTHAT :

Assembly code for gcd of two numbers .(M,N).

.MODEL SMALL
.STACK 100H

.DATA
PROMPT_1 DB 'Enter the value of M = $'
PROMPT_2 DB 0DH,0AH,'Enter the value of N = $'
PROMPT_3 DB 0DH,0AH,'The GCD of M and N is = $'

.CODE
MAIN PROC
MOV AX, @DATA
MOV DS, AX

LEA DX, PROMPT_1
MOV AH, 9
INT 21H

CALL INDEC

PUSH AX   

LEA DX, PROMPT_2
MOV AH, 9
INT 21H

CALL INDEC   

MOV BX, AX   

POP AX

@REPEAT:   
XOR DX, DX   
DIV BX   

CMP DX, 0
JE @END_LOOP

MOV AX, BX   
MOV BX, DX   
JMP @LOOP

@END_LOOP:   

LEA DX, PROMPT_3
MOV AH, 9
INT 21H

MOV AX, BX

CALL OUTDEC   

MOV AH, 4CH   
INT 21H
MAIN ENDP