gcc-4.4.0/gcc/testsuite/gcc.c-torture/execute/builtins/lib/bzero.c

extern int inside_main;

void
bzero (void *s, __SIZE_TYPE__ n)
{
  char *p;

  for (p = s; n-- > 0; p++)
    *p = 0;

#ifdef __OPTIMIZE__
  if (inside_main)
    abort ();
#endif
}