extern void abort(void);
extern void __assert_fail(const char *, const char *, unsigned int, const char *) __attribute__ ((__nothrow__ , __leaf__)) __attribute__ ((__noreturn__));
void reach_error() { __assert_fail("0", "signextension-1.c", 3, "reach_error"); }

int main() {

  unsigned short int allbits = -1;
  short int signedallbits = allbits;
  int unsignedtosigned = allbits;
  unsigned int unsignedtounsigned = allbits;
  int signedtosigned = signedallbits;
  unsigned int signedtounsigned = signedallbits;

  /*
  printf ("unsignedtosigned: %d\n", unsignedtosigned);
  printf ("unsignedtounsigned: %u\n", unsignedtounsigned);
  printf ("signedtosigned: %d\n", signedtosigned);
  printf ("signedtounsigned: %u\n", signedtounsigned);
  */

  if (unsignedtosigned == 65535 && unsignedtounsigned == 65535
      && signedtosigned == -1 && signedtounsigned == 4294967295) {
    goto ERROR;
  }

  return (0);
  ERROR: {reach_error();abort();}
  return (-1);
}