以下是引用Devil_W在2011-11-8 19:09:40的发言：

int strcmp(register const char *s1, register const char * s2)
{
         while (*s1 == *s2++)
                 if (*s1++ == 0)
                         return (0);
         return (*(const unsigned char *)s1 - *(const unsigned char *)(s2 - 1));
}