shixi111.asm

这是用汇编语言编写的关于十进制表达式的程序！输入完表达式之后

data segment
  opnd dw 100 dup(?)
  optr dw 100 dup(?)
  topopnd dw ?
  topoptr dw ?
  flag dw 0
  mess db 'REZULT:','$'
  op dw ?
  ordnum db '+','-','*','/','(',')','#'
  ordtable dw 0,0,1,1,1,0,0    ;符号的优先次序
           dw 0,0,1,1,1,0,0
           dw 0,0,0,0,1,0,0
           dw 0,0,0,0,1,0,0
           dw 1,1,1,1,1,2,4
           dw 0,0,0,0,4,0,0
           dw 1,1,1,1,1,4,3
  branch_table dw routine_1
               dw routine_2
               dw routine_3
               ;dw routine_4
  branch_table2 dw routine2_1    
                dw routine2_2            
                dw routine2_3
                dw routine2_4
data ends
code segment
  main proc far
   assume cs:code,ds:data
start:  
  push ds
  sub ax,ax
  push ax
  mov ax,data
  mov ds,ax
  mov si,0
  mov di,0
  mov optr[di],6d
  mov topoptr,0d
newchar:      ;输入表达式
  mov ah,1h
  int 21h
  cmp al,30h
  jl dealop   ; 输入的是运算符号
  mov flag,0h
  sub al,30h  ;ASSCII to binary
  cbw
  xchg ax,bx   ;把二进制转换成十进制
  mov cx,10d
  mul cx
  xchg ax,bx
  add bx,ax
  jmp newchar
dealop:       ; 处理运算符号
  cmp flag,1h
  jz next
  mov opnd[si],bx ;把操作数存入opnd
  mov topopnd,si
  add si,2
next:
  mov flag,1h
  push si
  mov si,0
findnum:
  cmp al,ordnum[si]
  jz next1
  inc si
  jmp findnum
next1:
  mov ax,si
  ;cmp ax,6d
  ;jnz next2
  ;mov flag1,1
;next2:
  ;mov bx,topoptr
  ;cmp optr[bx],6d
  ;jnz next3
  ;mov flag2,1
;next3:
  ;push ax
  ;mov ax,flag1
  ;mul flag2
  ;pop ax
  ;jnz return;not complete........
  mov bx,topoptr
  mov op,ax
  mov ax,2
  mul op
  mov si,ax
  mov ax,14
  mul optr[bx]
  mov bx,ax
  mov ax,ordtable[bx][si]
  cmp ax,3;------------ \\\\\\\\\
  jz exit1;--------------\\\\\\\\
  mov cx,2
  mul cx
  mov si,ax
  jmp branch_table[si]
exit1:
  jmp exit
routine_1:
    mov di,topoptr   ；初始化操作符栈顶指针
    mov si,optr[di]
    mov ax,si
    mov cx,2
    mul cx
    mov si,ax
    mov bx,0;----------------------------------
    jmp  branch_table2[si]
routine_2:             ；操作符栈顶的弹出
    add di,2
    mov cx,op
    mov optr[di],cx
    mov topoptr,di
    pop si
    mov bx,0;----------------------------------
    jmp newchar
routine_3:        ；操作数的弹出
   sub di,2
   pop si
   mov bx,0;-----------------------------------
   jmp newchar
;routine_4:       ；显示字符串
 ;  mov ah,09h
  ; lea dx,mess
   ;int 21h
   ;mov dx,0
   ;mov bx,opnd[0]
   ;call binidec
   ;ret
routine2_1:  ;做加法处理
   ;pop si
   mov di,topoptr
   sub di,2
   mov topoptr,di
   mov si,topopnd
   mov ax,opnd[si]
   add opnd[si-2],ax
   sub si,2
   mov topopnd,si
   add si,2
   push si
   mov ax,2
   mul op
   mov si,ax
   mov ax,14
   mul optr[di]
   mov bx,ax
   mov ax,ordtable[bx][si]
   cmp ax,3;------------ \\\\\\\\\
   jz exit2;--------------\\\\\\\\
   mov cx,2
   mul cx
   mov si,ax
   jmp branch_table[si]
exit2:
   jmp exit
routine2_2:;do '-'
   ;pop si
   mov di,topoptr
   sub di,2
   mov topoptr,di
   mov si,topopnd
   mov ax,opnd[si]
   sub opnd[si-2],ax
   sub si,2
   mov topopnd,si
   add si,2
   push si
   mov ax,2
   mul op
   mov si,ax
   mov ax,14
   mul optr[di]
   mov bx,ax
   mov ax,ordtable[bx][si]
   cmp ax,3;------------ \\\\\\\\\
  jz exit3;--------------\\\\\\\\
   mov cx,2
   mul cx
   mov si,ax
   jmp branch_table[si]
exit3:
   jmp exit
routine2_3:;do '*'
   ;pop si
   mov di,topoptr
   sub di,2
   mov topoptr,di
   mov si,topopnd
   mov ax,opnd[si]
   mul opnd[si-2]
   mov opnd[si-2],ax
   sub si,2
   mov topopnd,si
   add si,2
   push si
   mov ax,2
   mul op
   mov si,ax
   mov ax,14
   mul optr[di]
   mov bx,ax
   mov ax,ordtable[bx][si]
   cmp ax,3;------------ \\\\\\\\\
  jz exit;--------------\\\\\\\\
   mov cx,2
   mul cx
   mov si,ax
   jmp branch_table[si]
routine2_4:;do '/'
   ;pop si
   mov di,topoptr
   sub di,2
   mov topoptr,di
   mov si,topopnd
   mov ax,opnd[si-2]
   mov dx,0
   div opnd[si]
   mov opnd[si-2],ax
   sub si,2
   mov topopnd,si
   add si,2
   push si
   mov ax,2
   mul op
   mov si,ax
   mov ax,14
   mul optr[di]
   mov bx,ax
   mov ax,ordtable[bx][si]
   cmp ax,3;------------ \\\\\\\\\
  jz exit;--------------\\\\\\\\
   mov cx,2
   mul cx
   mov si,ax
   jmp branch_table[si]
exit:
   mov bx,opnd[0]
   call binidec
   mov ah,4ch
   int 21h
main endp
binidec proc near    ；输出处理
  mov cx,10000d
  call dec_div
  mov cx,1000d
  call dec_div
  mov cx,100d
  call dec_div
  mov cx,10d
  call dec_div
  mov cx,1d
  call dec_div
  ret
dec_div proc near    ；除法操作
   mov ax,bx
   mov dx,0
   div cx
   mov bx,dx
   mov dl,al
   add dl,30h
   mov ah,2h
   int 21h
   ret
dec_div endp
binidec endp
code ends
   end start