1 /*
2 This test checks promotion of bitfields. Bitfields should be promoted
3 very much like chars and shorts:
4
5 Bitfields (signed or unsigned) should be promoted to signed int if their
6 value will fit in a signed int, otherwise to an unsigned int if their
7 value will fit in an unsigned int, otherwise we don't promote them (ANSI/ISO
8 does not specify the behavior of bitfields larger than an unsigned int).
9
10 We test the behavior by subtracting two from the promoted value: this will
11 result in a negitive value for signed types, a positive value for unsigned
12 types. This test (of course) assumes that the compiler is correctly
13 implementing signed and unsigned arithmetic.
14 */
15
16 struct X {
17 unsigned int u3:3;
18 signed long int s31:31;
19 signed long int s32:32;
20 unsigned long int u31:31;
21 unsigned long int u32:32;
22 unsigned long long ull3 :3;
23 unsigned long long ull35:35;
24 unsigned u15:15;
25 };
26
27 struct X x;
28
main()29 main ()
30 {
31 if ((x.u3 - 2) >= 0) /* promoted value should be signed */
32 abort ();
33
34 if ((x.s31 - 2) >= 0) /* promoted value should be signed */
35 abort ();
36
37 if ((x.s32 - 2) >= 0) /* promoted value should be signed */
38 abort ();
39
40 if ((x.u15 - 2) >= 0) /* promoted value should be signed */
41 abort ();
42
43 /* Conditionalize check on whether integers are 4 bytes or larger, i.e.
44 larger than a 31 bit bitfield. */
45 if (sizeof (int) >= 4)
46 {
47 if ((x.u31 - 2) >= 0) /* promoted value should be signed */
48 abort ();
49 }
50 else
51 {
52 if ((x.u31 - 2) < 0) /* promoted value should be UNsigned */
53 abort ();
54 }
55
56 if ((x.u32 - 2) < 0) /* promoted value should be UNsigned */
57 abort ();
58
59 if ((x.ull3 - 2) >= 0) /* promoted value should be signed */
60 abort ();
61
62 if ((x.ull35 - 2) < 0) /* promoted value should be UNsigned */
63 abort ();
64
65 exit (0);
66 }
67