汇编指令学习

2023-12-15 18:29:16

1?栈和过程调用

```00000000 <swap>:
   0:    55                       push   %ebp
   1:    89 e5                    mov    %esp,%ebp
   3:    83 ec 10                 sub    $0x10,%esp
   6:    8b 45 08                 mov    0x8(%ebp),%eax
   9:    8b 00                    mov    (%eax),%eax
   b:    89 45 fc                 mov    %eax,-0x4(%ebp)
   e:    8b 45 0c                 mov    0xc(%ebp),%eax
  11:    8b 10                    mov    (%eax),%edx
  13:    8b 45 08                 mov    0x8(%ebp),%eax
  16:    89 10                    mov    %edx,(%eax)
  18:    8b 45 0c                 mov    0xc(%ebp),%eax
  1b:    8b 55 fc                 mov    -0x4(%ebp),%edx
  1e:    89 10                    mov    %edx,(%eax)
  20:    c9                       leave  
  21:    c3                       ret

?详解：

  1. ```00000000 <swap>:
  2. 0: 55? ? ? ?push %ebp
  3. 1: 89 e5? ? ?mov %esp,%ebp
  4. 3: 83 ec 10? ?sub $0x10,%esp? ? //分配16字节空间（10进制
  5. 6: 8b 45 08? ?mov 0x8(%ebp),%eax? //M[0x8(%ebp)]的参数移到%eax
  6. 9: 8b 00? ? ?mov (%eax),%eax? ?//将%eax指向的内存地址移到寄存器%eax
  7. b: 89 45 fc? ?mov %eax,-0x4(%ebp) //将%eax的值赋给基址-0x4(%ebp)
  8. e: 8b 45 0c? ?mov 0xc(%ebp),%eax //M[0xc(%ebp)]的参数移到%eax
  9. 11: 8b 10? ? mov (%eax),%edx?
  10. 13: 8b 45 08? mov 0x8(%ebp),%eax?
  11. 16: 89 10? ? mov %edx,(%eax)? ?//将%edx指向的值移到%eax指向的内存地址
  12. 18: 8b 45 0c? mov 0xc(%ebp),%eax? //
  13. 1b: 8b 55 fc? mov -0x4(%ebp),%edx //?
  14. 1e: 89 10? ? mov %edx,(%eax)? ?//将%edx指向的值移到%eax指向的内存地址
  15. 20: c9? ? ? leave
  16. 21: c3? ? ? ret

C语言代码参考?

int swap(int *x,int*y){
//**********Begin**********
    int t;
    t=*x;
    *x=*y;
    *y=t;


//**********End**********
}

2 条件/选择结构分析

? ? ? ? 2.1?if else条件选择结构

08049172 <main>:
 8049172:       8d 4c 24 04             lea    0x4(%esp),%ecx
 8049176:       83 e4 f0                and    $0xfffffff0,%esp
 8049179:       ff 71 fc                pushl  -0x4(%ecx)
 804917c:       55                      push   %ebp
 804917d:       89 e5                   mov    %esp,%ebp
 804917f:       51                      push   %ecx
 8049180:       83 ec 14                sub    $0x14,%esp
 8049183:       83 ec 04                sub    $0x4,%esp
 8049186:       8d 45 f0                lea    -0x10(%ebp),%eax
 8049189:       50                      push   %eax
 804918a:       8d 45 f4                lea    -0xc(%ebp),%eax
 804918d:       50                      push   %eax
 804918e:       68 08 a0 04 08          push   $0x804a008
 8049193:       e8 b8 fe ff ff          call   8049050 <__isoc99_scanf@plt>
 8049198:       83 c4 10                add    $0x10,%esp
 804919b:       8b 55 f4                mov    -0xc(%ebp),%edx
 804919e:       8b 45 f0                mov    -0x10(%ebp),%eax
 80491a1:       39 c2                   cmp    %eax,%edx
 80491a3:       7e 18                   jle    80491bd <main+0x4b>
 80491a5:       8b 55 f0                mov    -0x10(%ebp),%edx
 80491a8:       8b 45 f4                mov    -0xc(%ebp),%eax
 80491ab:       83 ec 04                sub    $0x4,%esp
 80491ae:       52                      push   %edx
 80491af:       50                      push   %eax
 80491b0:       68 0d a0 04 08          push   $0x804a00d
 80491b5:       e8 76 fe ff ff          call   8049030 <printf@plt>
 80491ba:       83 c4 10                add    $0x10,%esp
 80491bd:       8b 55 f4                mov    -0xc(%ebp),%edx
 80491c0:       8b 45 f0                mov    -0x10(%ebp),%eax
 80491c3:       39 c2                   cmp    %eax,%edx
 80491c5:       75 1a                   jne    80491e1 <main+0x6f>
 80491c7:       8b 55 f0                mov    -0x10(%ebp),%edx
 80491ca:       8b 45 f4                mov    -0xc(%ebp),%eax
 80491cd:       83 ec 04                sub    $0x4,%esp
 80491d0:       52                      push   %edx
 80491d1:       50                      push   %eax
 80491d2:       68 15 a0 04 08          push   $0x804a015
 80491d7:       e8 54 fe ff ff          call   8049030 <printf@plt>
 80491dc:       83 c4 10                add    $0x10,%esp
 80491df:       eb 18                   jmp    80491f9 <main+0x87>
 80491e1:       8b 55 f0                mov    -0x10(%ebp),%edx
 80491e4:       8b 45 f4                mov    -0xc(%ebp),%eax
 80491e7:       83 ec 04                sub    $0x4,%esp
 80491ea:       52                      push   %edx
 80491eb:       50                      push   %eax
 80491ec:       68 1d a0 04 08          push   $0x804a01d
 80491f1:       e8 3a fe ff ff          call   8049030 <printf@plt>
 80491f6:       83 c4 10                add    $0x10,%esp
 80491f9:       b8 00 00 00 00          mov    $0x0,%eax
 80491fe:       8b 4d fc                mov    -0x4(%ebp),%ecx
 8049201:       c9                      leave
 8049202:       8d 61 fc                lea    -0x4(%ecx),%esp
 8049205:       c3                      ret

?详解：

  1. 08049172 <main>:
  2. 8049172: 8d 4c 24 04? ? lea 0x4(%esp),%ecx
  3. 8049176: 83 e4 f0? ? ? and $0xfffffff0,%esp //16字节对齐
  4. 8049179: ff 71 fc? ? ? pushl -0x4(%ecx)
  5. 804917c: 55? ? ? ? ? push %ebp
  6. 804917d: 89 e5? ? ? ? mov %esp,%ebp
  7. 804917f: 51? ? ? ? ? push %ecx //把%ecx压入栈
  8. 8049180: 83 ec 14? ? ? sub $0x14,%esp
  9. 8049183: 83 ec 04? ? ? sub $0x4,%esp
  10. 8049186: 8d 45 f0? ? ? lea -0x10(%ebp),%eax //
  11. 8049189: 50? ? ? ? ? push %eax
  12. 804918a: 8d 45 f4? ? ? lea -0xc(%ebp),%eax
  13. 804918d: 50? ? ? ? ? push %eax
  14. 804918e: 68 08 a0 04 08? push $0x804a008
  15. 8049193: e8 b8 fe ff ff? call 8049050 <__isoc99_scanf@plt> //调用scanf
  16. 8049198: 83 c4 10? ? ? add $0x10,%esp //回收栈上的空间
  17. 804919b: 8b 55 f4? ? ? mov -0xc(%ebp),%edx // 内存的值赋给%edx
  18. 804919e: 8b 45 f0? ? ? mov -0x10(%ebp),%eax?// 内存的值赋给%eax
  19. 80491a1: 39 c2? ? ? ? cmp %eax,%edx //比较eax与edx
  20. 80491a3: 7e 18? ? ? ? jle 80491bd <main+0x4b> //小于就跳转到80491bd
  21. 80491a5: 8b 55 f0? ? ? mov -0x10(%ebp),%edx
  22. 80491a8: 8b 45 f4? ? ? mov -0xc(%ebp),%eax
  23. 80491ab: 83 ec 04? ? ? sub $0x4,%esp
  24. 80491ae: 52? ? ? ? ? push %edx
  25. 80491af: 50? ? ? ? ? push %eax
  26. 80491b0: 68 0d a0 04 08 push $0x804a00d
  27. 80491b5: e8 76 fe ff ff call 8049030 <printf@plt>
  28. 80491ba: 83 c4 10? ? ?add $0x10,%esp
  29. 80491bd: 8b 55 f4? ? ?mov -0xc(%ebp),%edx
  30. 80491c0: 8b 45 f0? ? ?mov -0x10(%ebp),%eax
  31. 80491c3: 39 c2? ? ? ?cmp %eax,%edx
  32. 80491c5: 75 1a? ? ? ?jne 80491e1 <main+0x6f> //不相等就跳转80491e1
  33. 80491c7: 8b 55 f0? ? ?mov -0x10(%ebp),%edx
  34. 80491ca: 8b 45 f4? ? ?mov -0xc(%ebp),%eax
  35. 80491cd: 83 ec 04? ? ?sub $0x4,%esp
  36. 80491d0: 52? ? ? ? ?push %edx
  37. 80491d1: 50? ? ? ? ?push %eax
  38. 80491d2: 68 15 a0 04 08 push $0x804a015
  39. 80491d7: e8 54 fe ff ff call 8049030 <printf@plt>
  40. 80491dc: 83 c4 10 ? ? add $0x10,%esp
  41. 80491df: eb 18 ? ? ? jmp 80491f9 <main+0x87>?
  42. 80491e1: 8b 55 f0 ? ? mov -0x10(%ebp),%edx
  43. 80491e4: 8b 45 f4? ? mov -0xc(%ebp),%eax
  44. 80491e7: 83 ec 04 ? ? sub $0x4,%esp
  45. 80491ea: 52 ? ? ? ? push %edx
  46. 80491eb: 50 ? ? ? ? push %eax
  47. 80491ec: 68 1d a0 04 08 push $0x804a01d
  48. 80491f1: e8 3a fe ff ff call 8049030 <printf@plt>
  49. 80491f6: 83 c4 10 ? ? add $0x10,%esp
  50. 80491f9: b8 00 00 00 00 mov $0x0,%eax
  51. 80491fe: 8b 4d fc ? ? mov -0x4(%ebp),%ecx
  52. 8049201: c9 ? ? ? ? leave
  53. 8049202: 8d 61 fc ? ? lea -0x4(%ecx),%esp
  54. 8049205: c3 ? ? ? ? ret

?C语言代码参考?

#include <stdio.h>
int main()
{
	int a, b;
	scanf("%d%d", &a, &b);
	printf("评测结果：成功\n评测脚本：C\n返回结果：");//此行不在汇编代码中
    //**********Begin**********
    if(a>b)
	//**********End************	
        printf("%d > %d", a, b);
	
    
    //**********Begin**********
   if(a==b)
	//**********End************    
    	printf("%d = %d", a, b);


    //**********Begin**********
    if(a<b)
    //**********End************
		printf("%d < %d", a, b);
    
    return 0;
}

?

????????2.2?switch选择结构

08049182 <main>:
 8049182:       8d 4c 24 04             lea    0x4(%esp),%ecx
 8049186:       83 e4 f0                and    $0xfffffff0,%esp
 8049189:       ff 71 fc                pushl  -0x4(%ecx)
 804918c:       55                      push   %ebp
 804918d:       89 e5                   mov    %esp,%ebp
 804918f:       51                      push   %ecx
 8049190:       83 ec 14                sub    $0x14,%esp
 8049193:       83 ec 08                sub    $0x8,%esp
 8049196:       8d 45 f4                lea    -0xc(%ebp),%eax
 8049199:       50                      push   %eax
 804919a:       68 08 a0 04 08          push   $0x804a008
 804919f:       e8 bc fe ff ff          call   8049060 <__isoc99_scanf@plt>
 80491a4:       83 c4 10                add    $0x10,%esp
 80491a7:       83 ec 0c                sub    $0xc,%esp
 80491aa:       68 0c a0 04 08          push   $0x804a00c
 80491af:       e8 7c fe ff ff          call   8049030 <printf@plt>
 80491b4:       83 c4 10                add    $0x10,%esp
 80491b7:       8b 45 f4                mov    -0xc(%ebp),%eax
 80491ba:       83 f8 06                cmp    $0x6,%eax
 80491bd:       77 73                   ja     8049232 <main+0xb0>
 80491bf:       8b 04 85 54 a0 04 08    mov    0x804a054(,%eax,4),%eax
 80491c6:       ff e0                   jmp    *%eax
 80491c8:       83 ec 0c                sub    $0xc,%esp
 80491cb:       68 43 a0 04 08          push   $0x804a043
 80491d0:       e8 6b fe ff ff          call   8049040 <puts@plt>
 80491d5:       83 c4 10                add    $0x10,%esp
 80491d8:       eb 69                   jmp    8049243 <main+0xc1>
 80491da:       83 ec 0c                sub    $0xc,%esp
 80491dd:       68 45 a0 04 08          push   $0x804a045
 80491e2:       e8 59 fe ff ff          call   8049040 <puts@plt>
 80491e7:       83 c4 10                add    $0x10,%esp
 80491ea:       eb 57                   jmp    8049243 <main+0xc1>
 80491ec:       83 ec 0c                sub    $0xc,%esp
 80491ef:       68 47 a0 04 08          push   $0x804a047
 80491f4:       e8 47 fe ff ff          call   8049040 <puts@plt>
 80491f9:       83 c4 10                add    $0x10,%esp
 80491fc:       eb 45                   jmp    8049243 <main+0xc1>
 80491fe:       83 ec 0c                sub    $0xc,%esp
 8049201:       68 49 a0 04 08          push   $0x804a049
 8049206:       e8 35 fe ff ff          call   8049040 <puts@plt>
 804920b:       83 c4 10                add    $0x10,%esp
 804920e:       eb 33                   jmp    8049243 <main+0xc1>
 8049210:       83 ec 0c                sub    $0xc,%esp
 8049213:       68 4b a0 04 08          push   $0x804a04b
 8049218:       e8 23 fe ff ff          call   8049040 <puts@plt>
 804921d:       83 c4 10                add    $0x10,%esp
 8049220:       83 ec 0c                sub    $0xc,%esp
 8049223:       68 4d a0 04 08          push   $0x804a04d
 8049228:       e8 13 fe ff ff          call   8049040 <puts@plt>
 804922d:       83 c4 10                add    $0x10,%esp
 8049230:       eb 11                   jmp    8049243 <main+0xc1>
 8049232:       83 ec 0c                sub    $0xc,%esp
 8049235:       68 4f a0 04 08          push   $0x804a04f
 804923a:       e8 01 fe ff ff          call   8049040 <puts@plt>
 804923f:       83 c4 10                add    $0x10,%esp
 8049242:       90                      nop
 8049243:       b8 00 00 00 00          mov    $0x0,%eax
 8049248:       8b 4d fc                mov    -0x4(%ebp),%ecx
 804924b:       c9                      leave
 804924c:       8d 61 fc                lea    -0x4(%ecx),%esp
 804924f:       c3                      ret

?详解：只看switch部分

  1. 80491b7: 8b 45 f4 ? ? ? ? mov -0xc(%ebp),%eax //把-0xc(%ebp)赋给%eax
  2. 80491ba: 83 f8 06 ? ? ? ? cmp $0x6,%eax
  3. 80491bd: 77 73 ? ? ? ? ? ja 8049232 <main+0xb0> //大于就跳转8049232
  4. 80491bf: 8b 04 85 54 a0 04 08 mov 0x804a054(,%eax,4),%eax?
  5. 80491c6: ff e0 ? ? ? ? ? jmp *%eax //间接跳转 跳到eax对应的值内
  6. 80491c8: 83 ec 0c ? ? ? ? sub $0xc,%esp
  7. 80491cb: 68 43 a0 04 08? ? ?push $0x804a043
  8. 80491d0: e8 6b fe ff ff? ? ?call 8049040 <puts@plt>
  9. 80491d5: 83 c4 10 ? ? ?? ?add $0x10,%esp
  10. 80491d8: eb 69 ? ? ?? ? ?jmp 8049243 <main+0xc1> //无条件跳转243
  11. 80491da: 83 ec 0c ? ? ?? ?sub $0xc,%esp
  12. 80491dd: 68 45 a0 04 08 ? ? push $0x804a045
  13. 80491e2: e8 59 fe ff ff ? ? call 8049040 <puts@plt>
  14. 80491e7: 83 c4 10? ? ? ? ?add $0x10,%esp
  15. 80491ea: eb 57? ? ? ? ? ?jmp 8049243 <main+0xc1>//无条件跳转243
  16. 80491ec: 83 ec 0c ? ? ? ? sub $0xc,%esp
  17. 80491ef: 68 47 a0 04 08? ? ?push $0x804a047
  18. 80491f4: e8 47 fe ff ff? ? ?call 8049040 <puts@plt>
  19. 80491f9: 83 c4 10 ? ? ? ? add $0x10,%esp
  20. 80491fc: eb 45? ? ? ? ? ?jmp 8049243 <main+0xc1>//无条件跳转243
  21. 80491fe: 83 ec 0c ? ? ? ? sub $0xc,%esp
  22. 8049201: 68 49 a0 04 08? ? ?push $0x804a049
  23. 8049206: e8 35 fe ff ff? ? ?call 8049040 <puts@plt>
  24. 804920b: 83 c4 10 ? ? ? ? add $0x10,%esp
  25. 804920e: eb 33? ? ? ? ? jmp 8049243 <main+0xc1>//无条件跳转243
  26. 8049210: 83 ec 0c ? ? ? ? sub $0xc,%esp
  27. 8049213: 68 4b a0 04 08? ? push $0x804a04b
  28. 8049218: e8 23 fe ff ff? ? call 8049040 <puts@plt>
  29. 804921d: 83 c4 10? ? ? ? add $0x10,%esp
  30. 8049220: 83 ec 0c? ? ? ?sub $0xc,%esp
  31. 8049223: 68 4d a0 04 08? ?push $0x804a04d
  32. 8049228: e8 13 fe ff ff? ?call 8049040 <puts@plt>
  33. 804922d: 83 c4 10? ? ? ?add $0x10,%esp
  34. 8049230: eb 11? ? ? ? ?jmp 8049243 <main+0xc1>//无条件跳转243
  35. 8049232: 83 ec 0c? ? ? ?sub $0xc,%esp
  36. 8049235: 68 4f a0 04 08? ?push $0x804a04f
  37. 804923a: e8 01 fe ff ff? ?call 8049040 <puts@plt>
  38. 804923f: 83 c4 10? ? ? ?add $0x10,%esp
  39. 8049242: 90 ? ? ? ? ??nop
  40. 8049243: b8 00 00 00 00 ? mov $0x0,%eax
  41. 8049248: 8b 4d fc ? ? ? mov -0x4(%ebp),%ecx
  42. 804924b: c9 leave
  43. 804924c: 8d 61 fc lea -0x4(%ecx),%esp
  44. 804924f: c3 ret

?C语言代码参考?

#include <stdio.h>
int main()
{
	int a;
	scanf("%d", &a);
	printf("评测结果：成功\n评测脚本：C\n返回结果：");
	switch (a)
	{   
		case 1:
			printf("1\n");
			break;
		//**********Begin********
		case 2:
			printf("2\n");
			break;
        case 3:
			printf("3\n");
			break;
        case 4:
			printf("4\n");
			break;
        case 5:
			printf("5\n");
            printf("6\n");
			break;
        case 6:
			printf("6\n");
			break;
        default: printf("else"); break;
    	//**********End**********
	}
	return 0;
}

3 循环结构分析

????????3.1?for 循环结构

08049172 <main>:
 8049172:       8d 4c 24 04             lea    0x4(%esp),%ecx
 8049176:       83 e4 f0                and    $0xfffffff0,%esp
 8049179:       ff 71 fc                pushl  -0x4(%ecx)
 804917c:       55                      push   %ebp
 804917d:       89 e5                   mov    %esp,%ebp
 804917f:       51                      push   %ecx
 8049180:       83 ec 14                sub    $0x14,%esp
 8049183:       c7 45 f4 00 00 00 00    movl   $0x0,-0xc(%ebp)
 804918a:       83 ec 08                sub    $0x8,%esp
 804918d:       8d 45 f0                lea    -0x10(%ebp),%eax
 8049190:       50                      push   %eax
 8049191:       68 08 a0 04 08          push   $0x804a008
 8049196:       e8 b5 fe ff ff          call   8049050 <__isoc99_scanf@plt>
 804919b:       83 c4 10                add    $0x10,%esp
 804919e:       eb 0c                   jmp    80491ac <main+0x3a>
 80491a0:       8b 55 f0                mov    -0x10(%ebp),%edx
 80491a3:       8b 45 f0                mov    -0x10(%ebp),%eax
 80491a6:       0f af c2                imul   %edx,%eax
 80491a9:       01 45 f4                add    %eax,-0xc(%ebp)
 80491ac:       8b 45 f0                mov    -0x10(%ebp),%eax
 80491af:       8d 50 ff                lea    -0x1(%eax),%edx
 80491b2:       89 55 f0                mov    %edx,-0x10(%ebp)
 80491b5:       85 c0                   test   %eax,%eax
 80491b7:       75 e7                   jne    80491a0 <main+0x2e>
 80491b9:       83 ec 08                sub    $0x8,%esp
 80491bc:       ff 75 f4                pushl  -0xc(%ebp)
 80491bf:       68 08 a0 04 08          push   $0x804a008
 80491c4:       e8 67 fe ff ff          call   8049030 <printf@plt>
 80491c9:       83 c4 10                add    $0x10,%esp
 80491cc:       b8 00 00 00 00          mov    $0x0,%eax
 80491d1:       8b 4d fc                mov    -0x4(%ebp),%ecx
 80491d4:       c9                      leave
 80491d5:       8d 61 fc                lea    -0x4(%ecx),%esp
 80491d8:       c3                      ret

详解：只看for循环结构

  1. 804919e: c7 45 f4 00 00 00 00 movl $0x0,-0xc(%ebp) //把立即数0赋给地址
  2. 80491a5: eb 0a? ? ? ? ? ?jmp 80491b1 <main+0x3f>//跳转
  3. 80491a7: 8b 45 f4? ? ? ? ?mov -0xc(%ebp),%eax //i值传递
  4. 80491aa: 01 45 f0? ? ? ? ?add %eax,-0x10(%ebp)// i+sum
  5. 80491ad: 83 45 f4 01? ? ? ?addl $0x1,-0xc(%ebp)//i++
  6. 80491b1: 8b 45 ec? ? ? ? ? mov -0x14(%ebp),%eax //n值传递
  7. 80491b4: 39 45 f4 ? ? ? ? cmp %eax,-0xc(%ebp)? ?//比较i与n
  8. 80491b7: 7c ee? ? ? ? ? ?jl 80491a7 <main+0x35> //小于跳转
  9. 80491b9: 83 ec 08 ? ? ? ? sub $0x8,%esp
  10. 80491bc: ff 75 f0 ? ? ? ? pushl -0x10(%ebp)
  11. 80491bf: 68 08 a0 04 08? ? push $0x804a008
  12. 80491c4: e8 67 fe ff ff? ? call 8049030 <printf@plt>
  13. 80491c9: 83 c4 10? ? ? ? add $0x10,%esp
  14. 80491cc: b8 00 00 00 00? ? mov $0x0,%eax
  15. 80491d1: 8b 4d fc? ? ? ? mov -0x4(%ebp),%ecx
  16. 80491d4: c9 leave
  17. 80491d5: 8d 61 fc lea -0x4(%ecx),%esp
  18. 80491d8: c3 ret

?C语言代码参考?

#include <stdio.h>

int main()
{
	int n, i, sum = 0;
	scanf("%d", &n);
    printf("评测结果：成功\n评测脚本：C\n返回结果：");//此行不在汇编代码中
    //**********Begin**********
    for(i=1;i<n;i++)
    {
        sum+=i;
    }

    //**********End**********
	printf("%d", sum);
    return 0;
}

????????3.2 while 循环结构

08049172 <main>:
 8049172:       8d 4c 24 04             lea    0x4(%esp),%ecx
 8049176:       83 e4 f0                and    $0xfffffff0,%esp
 8049179:       ff 71 fc                pushl  -0x4(%ecx)
 804917c:       55                      push   %ebp
 804917d:       89 e5                   mov    %esp,%ebp
 804917f:       51                      push   %ecx
 8049180:       83 ec 14                sub    $0x14,%esp
 8049183:       c7 45 f4 00 00 00 00    movl   $0x0,-0xc(%ebp)
 804918a:       83 ec 08                sub    $0x8,%esp
 804918d:       8d 45 f0                lea    -0x10(%ebp),%eax
 8049190:       50                      push   %eax
 8049191:       68 08 a0 04 08          push   $0x804a008
 8049196:       e8 b5 fe ff ff          call   8049050 <__isoc99_scanf@plt>
 804919b:       83 c4 10                add    $0x10,%esp
 804919e:       eb 0c                   jmp    80491ac <main+0x3a>
 80491a0:       8b 55 f0                mov    -0x10(%ebp),%edx
 80491a3:       8b 45 f0                mov    -0x10(%ebp),%eax
 80491a6:       0f af c2                imul   %edx,%eax
 80491a9:       01 45 f4                add    %eax,-0xc(%ebp)
 80491ac:       8b 45 f0                mov    -0x10(%ebp),%eax
 80491af:       8d 50 ff                lea    -0x1(%eax),%edx
 80491b2:       89 55 f0                mov    %edx,-0x10(%ebp)
 80491b5:       85 c0                   test   %eax,%eax
 80491b7:       75 e7                   jne    80491a0 <main+0x2e>
 80491b9:       83 ec 08                sub    $0x8,%esp
 80491bc:       ff 75 f4                pushl  -0xc(%ebp)
 80491bf:       68 08 a0 04 08          push   $0x804a008
 80491c4:       e8 67 fe ff ff          call   8049030 <printf@plt>
 80491c9:       83 c4 10                add    $0x10,%esp
 80491cc:       b8 00 00 00 00          mov    $0x0,%eax
 80491d1:       8b 4d fc                mov    -0x4(%ebp),%ecx
 80491d4:       c9                      leave
 80491d5:       8d 61 fc                lea    -0x4(%ecx),%esp
 80491d8:       c3                      ret

详解：只看while循环结构

  1. 804919e: eb 0c? ? ?jmp 80491ac <main+0x3a>//无条件跳转
  2. 80491a0: 8b 55 f0? ?mov -0x10(%ebp),%edx
  3. 80491a3: 8b 45 f0? ?mov -0x10(%ebp),%eax
  4. 80491a6: 0f af c2? ?imul %edx,%eax
  5. 80491a9: 01 45 f4? ?add %eax,-0xc(%ebp) //sum=sum+n*n
  6. 80491ac: 8b 45 f0? ?mov -0x10(%ebp),%eax
  7. 80491af: 8d 50 ff? ?lea -0x1(%eax),%edx //减去一
  8. 80491b2: 89 55 f0? ?mov %edx,-0x10(%ebp)
  9. 80491b5: 85 c0? ? ?test %eax,%eax
  10. 80491b7: 75 e7? ? ?jne 80491a0 <main+0x2e>//非0跳转
  11. 80491b9: 83 ec 08? ?sub $0x8,%esp
  12. 80491bc: ff 75 f4? ?pushl -0xc(%ebp)
  13. 80491bf: 68 08 a0 04 08 push $0x804a008
  14. 80491c4: e8 67 fe ff ff call 8049030 <printf@plt>
  15. 80491c9: 83 c4 10? ?add $0x10,%esp
  16. 80491cc: b8 00 00 00 00 mov $0x0,%eax
  17. 80491d1: 8b 4d fc? ?mov -0x4(%ebp),%ecx
  18. 80491d4: c9 leave
  19. 80491d5: 8d 61 fc lea -0x4(%ecx),%esp
  20. 80491d8: c3 ret

C语言代码参考?

#include <stdio.h>

int main()
{
	int n, sum = 0;
	scanf("%d", &n);
    printf("评测结果：成功\n评测脚本：C\n返回结果：");//此行不在汇编代码中
    //**********Begin********
    while(n>0)
    {
        
        n--;
        sum=sum+n*n;
    }
	


    //**********End**********
	printf("%d", sum);
    return 0;
}

文章来源:https://blog.csdn.net/axxdxzz/article/details/135020070
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