大會JMP不跳

Question

的問題是，它並沒有在doi跳即使dl和bl是相等的。有人知道爲什麼

assume cs:code,ds:data 
data segment 
sir1 db "abc" 
l1 equ $-sir1 
sir2 db "a" 
l2 equ $-sir2 
bunbun db "Este!$" 
nu db "NU este!$" 
iesire db "Apasa Enter!$" 

data ends 

code segment 
start: 
    mov ax,data 
    mov ds,ax 

    mov bp,offset sir1 
    mov si,offset sir2 
    dec bp 
    push bp 
    push si 
    mov ah,l1 
    mov bh,l2 

unu: 
    pop si 
    pop bp 
    inc bp 
    dec ah 
    mov dl,sir1[bp] 
    mov bl,sir2[si] 
    push bp 
    push si 
    cmp dl,bl 
    je doi 
    cmp ah,0 
    je nu_bun 
    jmp unu 

doi: 
    inc si 
    inc bp 
    dec ah 
    mov dl,sir1[bp] 
    mov bl,sir2[si] 
    cmp dl,bl 
    jne unu 
    cmp bh,0 
    je bun 
    jmp doi 

bun: 
    mov dx,offset bunbun 
    mov ah,09h 
    int 21h 
    mov ah, 09h 
    mov dx,offset iesire 
    int 21h 
    mov ah, 0ah 
    int 21h 
    mov ax,4c00h 
    int 21h 

nu_bun: 
    mov dx,offset nu 
    mov ah,09h 
    int 21h 
    mov ah, 09h 
    mov dx,offset iesire 
    int 21h 
    mov ah, 0ah 
    int 21h 
    mov ax,4c00h 
    int 21h 

code ends 
end start 

Answer 1

doi: 
    xchg di, bp 
    mov cx, ax 
    xor ax, ax 

cmp_next: 
    lodsb 
    dec si 
    cmpsb 
    jnz not_equal 
    or al, al 
    jz do_equal 
    jmp cmp_next 

do_equal: 
    xchg di, bp 
    mov ax, cx 
    jmp somewhere_togo_when_equal 

not_equal: 
    xchg di, bp 
    mov ax, cx 
    jmp somewhere_togo_when_not_equal