1.1 传送指令
- push %ebp
- mov %esp,%ebp
- and $0xfffffff0,%esp //边界对齐指令,16字节对齐
- sub $0x20,%esp
- movl $0xa,0x10(%esp) //立即数10- 赋值给偏移量为0x10的基址寄存器esp
- movl $0x9,0x14(%esp) //立即数9赋值
- mov 0x10(%esp),%eax
- mov %eax,0x18(%esp) //立即数10赋值给0x18(%esp)
- mov 0x14(%esp),%eax
- mov %eax,0x1c(%esp) //立即数9赋值给0x1c(%esp)
- mov 0x1c(%esp),%eax
- mov %eax,0x8(%esp) //立即数9赋值给0x8(%esp)
- mov 0x18(%esp),%eax
- mov %eax,0x4(%esp) //立即数10赋值给0x4(%esp)
- movl $0x0,(%esp)
- call 41 <main+0x41>
- leave
- ret
参考代码:
#include"stdio.h"
int main(){
int a,b,c,d;
a=10,b=9;
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**********
c=a;
d=b;
//**********End**********
printf("%d,%d\n",c,d);
}
1.2 传送指令
- mov %esp,%ebp
- and $0xfffffff0,%esp
- sub $0x20,%esp
- movl $0xa,0x18(%esp) //立即数10- 赋值给偏移量为0x18的基址寄存器esp
- mov 0x18(%esp),%eax
- mov %eax,0x1c(%esp)
- mov 0x1c(%esp),%eax
- mov %eax,0x8(%esp) //立即数10- 赋值给- 0x8(%esp)
- mov 0x18(%esp),%eax
- mov %eax,0x4(%esp)
- movl $0x0,(%esp)
- call 31 <main+0x31>
- leave
- ret
参考代码:
#include"stdio.h"
int main(){
int a=10;
int 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********
b=a;
printf("%d,%d\n",a,b);
//**********End**********
}
2.1 加减运算指令
- push %ebp
- mov %esp,%ebp
- and $0xfffffff0,%esp
- sub $0x20,%esp movl
- movl $0x6,0x10(%esp) //立即数6- 赋值给偏移量为0x10的基址寄存器esp
- movl $0x64,0x14(%esp) //16进制 立即数为100
- mov 0x14(%esp),%eax
- mov 0x10(%esp),%edx
- sub %eax,%edx //将edx-eax的值赋值给edx
- mov %edx,%eax
- mov %eax,0x18(%esp) //将edx的值赋值给c
- mov 0x14(%esp),%eax
- mov 0x10(%esp),%edx
- add %edx,%eax //将eax+edx的值赋值给edx
- mov %eax,0x1c(%esp)
- mov 0x1c(%esp),%eax
- mov %eax,0x8(%esp) //将eax的值赋值给c
- mov 0x18(%esp),%eax
- mov %eax,0x4(%esp)
- movl $0x0,(%esp)
- call 4f <main+0x4f>
- leave
- ret
参考代码 :
#include"stdio.h"
int main(){
int a,b,c,d;
a=6,b=100;
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**********
c=a-b;
d=a+b;
//**********End**********
printf("%d,%d\n",c,d);
}
3.1 整数的乘法指令
- push %ebp
- mov %esp,%ebp
- and $0xfffffff0,%esp
- sub $0x20,%esp
- movl $0x3,0x10(%esp) //立即数3- 赋值给偏移量为0x10的基址寄存器esp
- mov 0x10(%esp),%eax
- sub $0x1,%eax //将eax的值-1赋给eax
- imul 0x10(%esp),%eax //将eax与- 0x10(%esp)内的值相乘赋给eax
- mov %eax,0x14(%esp) //赋值给b
- mov 0x10(%esp),%eax
- imul 0x14(%esp),%eax //将c与0x10(%esp)内的值相乘赋给eax
- mov %eax,0x18(%esp) //赋给c
- mov 0x18(%esp),%eax
- add $0x2,%eax //d+2的值赋给eax
- imul 0x10(%esp),%eax //eax与0x10(%esp)内的值相乘赋给eax
- mov %eax,0x1c(%esp) //赋给d
- mov 0x1c(%esp),%eax
- mov %eax,0x8(%esp)//赋给d
- mov 0x18(%esp),%eax
- mov %eax,0x4(%esp)
- movl $0x0,(%esp)
- call 56 <main+0x56>
- leave
- ret
参考代码:
#include"stdio.h"
int main(){
int a,b,c,d;
a=3;
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**********
b=a*(a-1);
c=a*b;
d=a*(c+2);
//**********End**********
printf("%d,%d\n",c,d);
}
4.1 控制转移指令
- 00000000 <sum>:
- 0: 55 push %ebp
- 1: 89 e5 mov %esp,%ebp
- 3: 83 ec 10 sub $0x10,%esp //分配十字节空间
- 6: c7 45 fc 00 00 00 00 movl $0x0,-0x4(%ebp) //s =0
- d: c7 45 f8 00 00 00 00 movl $0x0,-0x8(%ebp) //i =0
- 14: eb 18 jmp 2e <sum+0x2e>
- 16: 8b 45 f8 mov -0x8(%ebp),%eax //
- 19: 8d 14 85 00 00 00 00 lea 0x0(,%eax,4),%edx //a[i]的值赋给edx
- 20: 8b 45 08 mov 0x8(%ebp),%eax //
- 23: 01 d0 add %edx,%eax
- 25: 8b 00 mov (%eax),%eax
- 27: 01 45 fc add %eax,-0x4(%ebp) //s的值+a[i]赋给s
- 2a: 83 45 f8 01 addl $0x1,-0x8(%ebp) //i的值+1赋给i
- 2e: 8b 45 f8 mov -0x8(%ebp),%eax //i的值赋给eax
- 31: 3b 45 0c cmp 0xc(%ebp),%eax //比较i跟n的值;
- 34: 7c e0 jl 16 <sum+0x16>
- 36: 8b 45 fc mov -0x4(%ebp),%eax
- 39: c9 leave
- 3a: c3 ret
参考代码:
#include"stdio.h"
int sum(int a[],int n){
//**********Begin**********
int s = 0;
for (int i = 0;i<n; i++) {
s += a[i];
}
return s;
//**********End**********
}