Реализовать сложение, вычитание, умножение многочленов - Assembler

.model small
.stack 256
.386
.data
mes1 db 0Dh, 0Ah, 'Enter the degree: $'
mes2 db 0Dh, 0Ah, 'Enter the coef of x^$'
mes3 db ': $'
mes4 db 0Dh, 0Ah, 'Choose action: $'
mes5 db 0Dh, 0Ah, '= $'
polynom struc
    coef dw 256 dup ('0')
polynom ends
polynoms struc
    coefs dw 512 dup ('0')
polynoms ends
deg1 db 0
deg2 db 0
temp dw 0
signs db 0
pol1 polynom <>
pol2 polynom <>
res polynoms <>
.code
rchar proc
    mov ah, 1
    int 21h
    ret
rchar endp
wchar proc ; v AL dolzhen lezhat kod simvola
    push ax
    mov ah, 2
    mov dl, al
    int 21h
    pop ax
    ret
wchar endp
rnum proc ; v DX sohranyaetsa chislo
    push ax
    push bx
    push cx
    mov cx, 0
    mov bx, 1
    mov dx, 0
read:
    call rchar
    cmp al, 13
    je end_read
    cmp al, '-'
    je otr
    xor ah, ah
    sub al, '0'
    push ax
    inc cx
    jmp read
otr:
    mov signs, 1
    jmp read
end_read:
    pop ax
    mul bx
    add dx, ax
    mov ax, 10
    mul bx
    mov bx, ax
    loop end_read
    cmp signs, 1
    je change_sign
    jmp ender
change_sign:
    neg dx
ender:
    pop cx
    pop bx
    pop ax
    ret
rnum endp
wnum proc ; v AX dolzhno lezhat chislo
    push ax
    push bx
    push cx
    push dx
    test ax, ax
    js write_minus
    jmp write_num
write_minus:
    push ax
    push dx
    mov al, '-'
    call wchar
    pop dx
    pop ax
    neg ax
write_num:
    mov bl, 10
    mov cx, 0
divs:
    div bl
    add ah, '0'
    push ax
    inc cx
    cmp al, 0
    je end_div
    xor ah, ah
    jmp divs
end_div:
    pop ax
    mov al, ah
    call wchar
    loop end_div
    pop dx
    pop cx
    pop bx
    pop ax
    ret
wnum endp
input proc ; v BX dolzhen lezhat adres nachala polynoma, v AL - stepen polynoma
    push ax
    push bx
    push cx
    push dx
    xor ah, ah
    mov cx, ax
    inc cx
cycle:
    mov ah, 9
    lea dx, mes2
    int 21h
    xor ah, ah
    call wnum
    mov ah, 9
    lea dx, mes3
    int 21h
    call rnum
    xor ah, ah
    mov si, ax
    add si, si
    mov [bx + si], dx
    sub si, 2
    loop cycle
    pop dx
    pop cx
    pop bx
    pop ax
    ret
input endp
output proc ; v BX dolzhen lezhat adres nachala polynoma, v AX - stepen polynoma
    push ax
    push bx
    push cx
    push dx
    mov ah, 9
    lea dx, mes5
    int 21h
    mov cx, ax
    inc cx
    mov si, ax
    add si, si
cicl:
    mov ax, [bx + si]
    push bx
    push ax
    cmp ax, 0
    je skip
    test ax, ax
    jns write_plus
nazad:
    call wnum
    jmp sled
write_plus:
    mov al, '+'
    call wchar
    jmp nazad
sled:
    mov al, 'x'
    call wchar
    mov al, '^'
    call wchar
    pop ax
    mov bx, 2
    div bx
    call wnum
    sub si, 2
    pop bx
    loop cicl
    jmp rest
skip:
    sub si, 2
    pop ax
    pop bx
    loop cicl
rest:
    pop dx
    pop cx
    pop bx
    pop ax
    ret
output endp
start:
    mov ax, @data
    mov ds, ax
    mov ah, 9
    lea dx, mes1
    int 21h
    call rnum
    mov deg1, dl
    lea bx, pol1.coef
    mov al, deg1
    call input
    mov ah, 9
    lea dx, mes1
    int 21h
    call rnum
    mov deg2, dl
    lea bx, pol2.coef
    mov al, deg2
    call input
    mov ah, 4ch
    int 21h
end start