[Assembly] 어셈블리 구구단 출력

실행 환경

- cpu : intel(32bit)

- 컴파일러 : nasm

- 리눅스 : ubuntu 20.04 LTS

 

설치방법

- sudo apt-get install build-essential gcc-multiplib nasm

 

 

mul-test.c

#include <stdio.h>

void mul(int n)
{
		for (int i = 1; i < = 9; i++)
        printf("%d * %d = %d \n", n, i, n * i);
		return;
}

int main(void)
{
		int num_array[10] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 0};
		for (int i = 1; i < 9; i++)
				mul(num_array[i]);
		return 0;
}

 

 

mul-test.asm

extern printf

section .data
    msg db "%d * %d = %d", 0x0A

section .text
    global main

mul_func:
    push ebp
    mov ebp,esp
    sub esp,4 ; i(지역변수 공간 확보)
    mov DWORD [ebp-4], 1 ; i = 1
    jmp S2 ; for loop starts

S1:
    mov eax, DWORD [ebp-4]
    mul DWORD [ebp+8]
    push eax; n*i
    push DWORD [ebp-4]; i
    push DWORD [ebp+8]; n 
    push msg; "%d * %d = %d \n"
    call printf ; printf(); 
    add esp, 16 ; clear arguments of printf
    add DWORD [ebp-4], 1 ; i++


S2:
    cmp DWORD [ebp-4], 0x9 ; compare i and 9
    jle S1 ; jump if less or equal

    leave ; function epilogue starts
    ret ; function epilogue ends


main:
    push ebp
    mov ebp,esp

    sub esp,44 ; int num_array
    mov DWORD [ebp-4],0
    mov DWORD [ebp-8],9
    mov DWORD [ebp-12],8
    mov DWORD [ebp-16],7
    mov DWORD [ebp-20],6
    mov DWORD [ebp-24],5
    mov DWORD [ebp-28],4
    mov DWORD [ebp-32],3
    mov DWORD [ebp-36],2
    mov DWORD [ebp-40],1 ; int num_array[10] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 0}
    mov DWORD [ebp-44],1 ; i = 1
    jmp L2

L1:
    mov eax, [ebp-44] ; i
    push DWORD [ebp-44+eax*4] ; send argument : num_array[i] char * ptr; (array+ptr*4)
    call mul_func ; mul_func(int n);
    add esp, 4 ; clear arguments of mul_func
    add DWORD [ebp-44], 1 ; i++

L2:
    cmp DWORD [ebp-44], 0x9 ; compare i and 9
    jl L1 ; jump if less

    leave ; function epilogue starts
    ret ; function epilogue ends

1. __cdecl 함수 호출 규약을 따름.

2. printf 함수를 extern하여 사용함. -> gcc로 컴파일 하였다.