gnu / gcc / d769c5040874bf9546f2524f3f1d2a894165f92a / . / gcc / testsuite / gcc.c-torture / execute / bf-sign-2.c

/* | |

This test checks promotion of bitfields. Bitfields should be promoted | |

very much like chars and shorts: | |

Bitfields (signed or unsigned) should be promoted to signed int if their | |

value will fit in a signed int, otherwise to an unsigned int if their | |

value will fit in an unsigned int, otherwise we don't promote them (ANSI/ISO | |

does not specify the behavior of bitfields larger than an unsigned int). | |

We test the behavior by subtracting two from the promoted value: this will | |

result in a negitive value for signed types, a positive value for unsigned | |

types. This test (of course) assumes that the compiler is correctly | |

implementing signed and unsigned arithmetic. | |

*/ | |

struct X { | |

unsigned int u3:3; | |

signed long int s31:31; | |

signed long int s32:32; | |

unsigned long int u31:31; | |

unsigned long int u32:32; | |

unsigned long long ull3 :3; | |

unsigned long long ull35:35; | |

unsigned u15:15; | |

}; | |

struct X x; | |

main () | |

{ | |

if ((x.u3 - 2) >= 0) /* promoted value should be signed */ | |

abort (); | |

if ((x.s31 - 2) >= 0) /* promoted value should be signed */ | |

abort (); | |

if ((x.s32 - 2) >= 0) /* promoted value should be signed */ | |

abort (); | |

if ((x.u15 - 2) >= 0) /* promoted value should be signed */ | |

abort (); | |

/* Conditionalize check on whether integers are 4 bytes or larger, i.e. | |

larger than a 31 bit bitfield. */ | |

if (sizeof (int) >= 4) | |

{ | |

if ((x.u31 - 2) >= 0) /* promoted value should be signed */ | |

abort (); | |

} | |

else | |

{ | |

if ((x.u31 - 2) < 0) /* promoted value should be UNsigned */ | |

abort (); | |

} | |

if ((x.u32 - 2) < 0) /* promoted value should be UNsigned */ | |

abort (); | |

if ((x.ull3 - 2) >= 0) /* promoted value should be signed */ | |

abort (); | |

if ((x.ull35 - 2) < 0) /* promoted value should be UNsigned */ | |

abort (); | |

exit (0); | |

} |