检测比较结果条件转移指令

发表于 | 分类于 | 阅读次数 | 字数： 439 
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if(ah==ah){
  ah=+ah;
}else{
  ah=+bh;
}

对应的汇编命令

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assume cs:code

code segment
start:	mov ah,1h
		mov bh,1h
		
		cmp ah,bh
		je s
		add ah,bh
		jmp ok  

	s:	add ah,ah
	ok:	mov ax,4c00h
		int 21
	
code ends
end start

2）统计data段中的数值为8的字节个数，用ax保存统计结果

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assume cs:code
data segment
db 8,11,8,1,8,5,63,38
data ends
code segment
start: mov ax,data
	   mov ds,ax
	   mov ax,0
	   mov bx,0
	   mov cx,8
	   
	 s: cmp byte ptr [bx],8
		jne next
		inc ax
  next: inc bx
		loop s
	
	mov ax,4c00h
	int 21
code ends
end start

方法二：

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	assume cs:code
data segment
db 8,11,8,1,8,5,63,38
data ends
code segment
start: mov ax,data
	   mov ds,ax
	   mov ax,0
	   mov bx,0
	   mov cx,8
	   
	 s: cmp byte ptr [bx],8
		je ok
		jmp short next
    ok: inc ax
  next: inc bx
		loop s
	
	mov ax,4c00h
	int 21
code ends
end start

3）统计data段中数值大于8的字节的个数，用ax保存统计结果

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assume cs:code
data segment
db 8,11,8,1,8,5,63,38
data ends
code segment
start: mov ax,data
	   mov ds,ax
	   mov ax,0
	   mov bx,0
	   mov cx,8
	   
	 s: cmp byte ptr [bx],8
		ja ok
		jmp short next
    ok: inc ax
  next: inc bx
		loop s
	
	mov ax,4c00h
	int 21
code ends
end start

方法二：

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assume cs:code
data segment
db 8,11,8,1,8,5,63,38
data ends
code segment
start: mov ax,data
	   mov ds,ax
	   mov ax,0
	   mov bx,0
	   mov cx,8
	   
	 s: cmp byte ptr [bx],8
		jna next
		inc ax
  next: inc bx
		loop s
	
	mov ax,4c00h
	int 21
code ends
end start

4）统计data段中数值小于8的字节个数，用ax保存统计结果

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assume cs:code
data segment
db 8,11,8,1,8,5,63,38
data ends
code segment
start: mov ax,data
	   mov ds,ax
	   mov ax,0
	   mov bx,0
	   mov cx,8
	   
	 s: cmp byte ptr [bx],8
		jnb next
		inc ax
  next: inc bx
		loop s
	
	mov ax,4c00h
	int 21
code ends
end start