linux下将C语言编译为汇编代码，需用-S参数，如下代码
void fun(int a,int b)
{
/*这个函数什么也不做*/
}
int main(void)
{
fun(100,200);
return 0;
}
编译命令为：
$ gcc -S s1.c
编译后的结果为：
1 .file "s1.c"
2 .text
3 .globl fun
4 .type fun, @function
5 fun:
6 pushl %ebp
7 movl %esp, %ebp
8 popl %ebp
9 ret
10 .size fun, .-fun
11 .globl main
12 .type main, @function
13 main:
14 pushl %ebp
15 movl %esp, %ebp
16 subl $8, %esp
17 movl $200, 4(%esp)
18 movl $100, (%esp)
19 call fun
20 movl $0, %eax
21 leave
22 ret
23 .size main, .-main
24 .ident "GCC: (Ubuntu/Linaro 4.4.4-14ubuntu5) 4.4.5"
25 .section .note.GNU-stack,"",@progbits