LINUX-C-编译内存对齐问题

#include <stdio.h>
int main(void){
struct  YY
{
long long i;
char c1;
char c2;

};
printf("%d\n",sizeof(struct YY));
}

 deepfuture@deepfuture-laptop:~/private/mytest$ gcc -o test13 test13.c

deepfuture@deepfuture-laptop:~/private/mytest$ ./test13

12

deepfuture@deepfuture-laptop:~/private/mytest$