gcc/testsuite/gcc.dg/torture/pr37868.c

   1 /* { dg-do run } */
   2 /* { dg-options "-fno-strict-aliasing" } */
   3 /* { dg-skip-if "unaligned access" { sparc*-*-* } "*" "" } */
   4
   5 extern void abort (void);
   6
   7 struct X {
   8   unsigned char pad : 4;
   9   unsigned int a : 32;
  10   unsigned int b : 24;
  11   unsigned int c : 6;
  12 } __attribute__((packed));
  13
  14 int main (void)
  15 {
  16   struct X x;
  17   unsigned int bad_bits;
  18
  19   x.pad = -1;
  20   x.a = -1;
  21   x.b = -1;
  22   x.c = -1;
  23
  24   bad_bits = ((unsigned int)-1) ^ *(1+(unsigned int *) &x);
  25   if (bad_bits != 0)
  26     abort ();
  27   return 0;
  28 }
  29