1  extern void abort (void);
       2  extern int inside_main;
       3  
       4  typedef __SIZE_TYPE__ size_t;
       5  
       6  __attribute__ ((__noinline__))
       7  int
       8  strncmp(const char *s1, const char *s2, size_t n)
       9  {
      10    const unsigned char *u1 = (const unsigned char *)s1;
      11    const unsigned char *u2 = (const unsigned char *)s2;
      12    unsigned char c1, c2;
      13  
      14  #ifdef __OPTIMIZE__
      15    if (inside_main)
      16      abort();
      17  #endif
      18  
      19    while (n > 0)
      20      {
      21        c1 = *u1++, c2 = *u2++;
      22        if (c1 == '\0' || c1 != c2)
      23  	return c1 - c2;
      24        n--;
      25      }
      26    return c1 - c2;
      27  }