汇编BCD

<pre><code class=”lang-bash”>section .text
global _start ;must be declared for using gcc

_start: ;tell linker entry point

mov esi, 4 ;pointing to the rightmost digit
mov ecx, 5 ;num of digits
clc
add_loop:
mov al, [num1 + esi]
adc al, [num2 + esi]
aaa
pushf
or al, 30h
popf

mov [sum + esi], al
dec esi
loop add_loop

mov edx,len ;message length
mov ecx,msg ;message to write
mov ebx,1 ;file descriptor (stdout)
mov eax,4 ;system call number (sys_write)
int 0x80 ;call kernel

mov edx,5 ;message length
mov ecx,sum ;message to write
mov ebx,1 ;file descriptor (stdout)
mov eax,4 ;system call number (sys_write)
int 0x80 ;call kernel

mov eax,1 ;system call number (sys_exit)
int 0x80 ;call kernel

section .data
msg db 'The Sum is:',0xa
len equ $ – msg
num1 db '12345'
num2 db '23456'
sum db ' '
</code></pre>