1/* Copyright 2002 Free Software Foundation, Inc.
2
3   Tests correct signedness of operations on bitfields; in particular
4   that integer promotions are done correctly, including the case when
5   casts are present.
6
7   The C front end was eliding the cast of an unsigned bitfield to
8   unsigned as a no-op, when in fact it forces a conversion to a
9   full-width unsigned int. (At the time of writing, the C++ front end
10   has a different bug; it erroneously promotes the uncast unsigned
11   bitfield to an unsigned int).
12
13   Source: Neil Booth, 25 Jan 2002, based on PR 3325 (and 3326, which
14   is a different manifestation of the same bug).
15*/
16
17extern void abort ();
18
19int
20main(int argc, char *argv[])
21{
22  struct x { signed int i : 7; unsigned int u : 7; } bit;
23
24  unsigned int u;
25  int i;
26  unsigned int unsigned_result = -13U % 61;
27  int signed_result = -13 % 61;
28
29  bit.u = 61, u = 61;
30  bit.i = -13, i = -13;
31
32  if (i % u != unsigned_result)
33    abort ();
34  if (i % (unsigned int) u != unsigned_result)
35    abort ();
36
37  /* Somewhat counter-intuitively, bit.u is promoted to an int, making
38     the operands and result an int.  */
39  if (i % bit.u != signed_result)
40    abort ();
41
42  if (bit.i % bit.u != signed_result)
43    abort ();
44
45  /* But with a cast to unsigned int, the unsigned int is promoted to
46     itself as a no-op, and the operands and result are unsigned.  */
47  if (i % (unsigned int) bit.u != unsigned_result)
48    abort ();
49
50  if (bit.i % (unsigned int) bit.u != unsigned_result)
51    abort ();
52
53  return 0;
54}
55