汇编语言-求分段函数值

 计算函数值

1. 题目：计算给定函数值
2. 要求：编制程序，计算下面函数值
   

其中，从键盘输入x,y，输出数据为a。

输入输出时候都要求有提示信息。

考查知识点：分支结构的应用。

代码如下：

 1 ; Example assembly language program -- 

 2 ; Author:  karllen

 3 ; Date:    revised 5/2014

 4 

 5 .386

 6 .MODEL FLAT

 7 

 8 ExitProcess PROTO NEAR32 stdcall, dwExitCode:DWORD

 9 

10 INCLUDE io.h            ; header file for input/output

11 

12 cr      EQU     0dh     ; carriage return character

13 Lf      EQU     0ah     ; line feed

14 

15 .STACK  4096            ; reserve 4096-byte stack

16 

17 .DATA

18       promotX  BYTE "Please enter a number as X ",0

19       promotY  BYTE "Please enter a number as Y ",0

20       value    BYTE 11 DUP(?)

21       answer   BYTE "The a is"

22         rsa    BYTE 11 DUP(?)

23                BYTE cr,Lf,0

24 .CODE

25 _start:

26       output   promotX       ;ebx = x

27       input    value,11

28       atod     value

29       mov      ebx,eax

30       

31       output   promotY       ;eax = y

32       input    value,11

33       atod     value

34       

35       cmp      ebx,0

36       jl       lzero         ;ebx < 0

37       

38       cmp      ebx,0

39       jg       oo            ;x>0

40       oo: 

41            cmp eax,0 

42            jl  oneg          ;y<0

43       cmp      eax,0         ;ebx>=0

44       jge      ltwozero      ;eax>=0

45      lzero:

46            cmp    eax,0

47            jl     ltwzero      ;eax < 0    

48      oneg:

49            mov     eax,0

50            dtoa   rsa,eax

51            output answer

52            jmp    endCMP      

53      ltwzero:

54            mov    eax,1

55            neg    eax

56            dtoa   rsa,eax

57            output answer

58            jmp    endCMP

59      ltwozero:

60            mov    eax,1

61            dtoa   rsa,eax

62            output answer

63      endCMP:

64       

65               INVOKE  ExitProcess, 0  ; exit with return code 0

66 

67 PUBLIC _start                   ; make entry point public

68 

69 END                             ; end of source code

测试结果