利用汇编实现表驱动

看Intel汇编语言程序设计的，感觉蛮有意思的

  
    

   
      1 
   
     INCLUDE irvine32.
   
     inc
   
     

   
      2 
   
     

   
      3 
   
     .data

   
      4 
   
     CaseTable BYTE 
   
     '
   
     A
   
     '
   
     

   
      5 
   
      DWORD PROCESS_A

   
      6 
   
     EntrySize = ($ - CaseTable)

   
      7 
   
      BYTE 
   
     '
   
     B
   
     '
   
     

   
      8 
   
      DWORD PROCESS_B

   
      9 
   
      BYTE 
   
     '
   
     C
   
     '
   
     

   
     10 
   
      DWORD PROCESS_C

   
     11 
   
      BYTE 
   
     '
   
     D
   
     '
   
     

   
     12 
   
      DWORD PROCESS_D 

   
     13 
   
     NumberOfEntries = ($-CaseTable)/EntrySize

   
     14 
   
     prompt BYTE 
   
     "
   
     Press capital A,B,C,or D:
   
     "
   
     ,
   
     0
   
     

   
     15 
   
     

   
     16 
   
     msgA BYTE 
   
     "
   
     PROCESS_A
   
     "
   
     ,
   
     0
   
     

   
     17 
   
     msgB BYTE 
   
     "
   
     PROCESS_B
   
     "
   
     ,
   
     0
   
     

   
     18 
   
     msgC BYTE 
   
     "
   
     PROCESS_C
   
     "
   
     ,
   
     0
   
     

   
     19 
   
     msgD BYTE 
   
     "
   
     PROCESS_D
   
     "
   
     ,
   
     0
   
     

   
     20 
   
     

   
     21 
   
     .code

   
     22 
   
     

   
     23 
   
     main PROC

   
     24 
   
      
   
     mov
   
      edx,OFFSET prompt

   
     25 
   
      
   
     call
   
      WriteString

   
     26 
   
      
   
     call
   
      ReadChar

   
     27 
   
      
   
     mov
   
      ebx,OFFSET CaseTable

   
     28 
   
      
   
     mov
   
      ecx,NumberOfEntries

   
     29 
   
     
   
     L1:
   
     

   
     30 
   
      
   
     cmp
   
      al,[ebx]

   
     31 
   
      
   
     jne
   
      L2

   
     32 
   
      
   
     call
   
      NEAR PTR [ebx+
   
     1
   
     ]

   
     33 
   
      
   
     call
   
      WriteString

   
     34 
   
      
   
     call
   
      Crlf

   
     35 
   
      
   
     jmp
   
      L3

   
     36 
   
     
   
     L2:
   
     

   
     37 
   
      
   
     add
   
      ebx,EntrySize

   
     38 
   
     loop L1

   
     39 
   
     

   
     40 
   
     
   
     L3:
   
     

   
     41 
   
      
   
     ret
   
     

   
     42 
   
     main endp

   
     43 
   
     

   
     44 
   
     PROCESS_A PROC

   
     45 
   
      

   
     46 
   
      
   
     mov
   
      edx,OFFSET msgA

   
     47 
   
      
   
     ret
   
     

   
     48 
   
     

   
     49 
   
     PROCESS_A endp

   
     50 
   
     

   
     51 
   
     PROCESS_B PROC

   
     52 
   
      

   
     53 
   
      
   
     mov
   
      edx,OFFSET msgB

   
     54 
   
      
   
     ret
   
     

   
     55 
   
     

   
     56 
   
     PROCESS_B endp

   
     57 
   
     

   
     58 
   
     PROCESS_C PROC

   
     59 
   
      

   
     60 
   
      
   
     mov
   
      edx,OFFSET msgC

   
     61 
   
      
   
     ret
   
     

   
     62 
   
     

   
     63 
   
     PROCESS_C endp

   
     64 
   
     

   
     65 
   
     PROCESS_D PROC

   
     66 
   
      

   
     67 
   
      
   
     mov
   
      edx,OFFSET msgD

   
     68 
   
      
   
     ret
   
     

   
     69 
   
     

   
     70 
   
     PROCESS_D endp

   
     71 
   
     

   
     72 
   
     Debug PROC

   
     73 
   
      

   
     74 
   
      
   
     pushad
   
     

   
     75 
   
      
   
     mov
   
      edx,OFFSET Debug

   
     76 
   
      
   
     call
   
      WriteString

   
     77 
   
      
   
     popad
   
     

   
     78 
   
      
   
     ret
   
     

   
     79 
   
     

   
     80 
   
     Debug endp

   
     81 
   
     

   
     82 
   
     END main