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

   1 /* { dg-do run } */
   2 /* { dg-options "-fno-strict-aliasing" } */
   3 /* { dg-skip-if "unaligned access" { arc*-*-* epiphany-*-* nds32*-*-* sparc*-*-* sh*-*-* tic6x-*-* } "*" "" } */
   4
   5 extern void abort (void);
   6 #if (__SIZEOF_INT__ <= 2)
   7 struct X {
   8   unsigned char pad : 4;
   9   unsigned int a : 16;
  10   unsigned int b : 8;
  11   unsigned int c : 6;
  12 } __attribute__((packed));
  13 #else
  14 struct X {
  15   unsigned char pad : 4;
  16   unsigned int a : 32;
  17   unsigned int b : 24;
  18   unsigned int c : 6;
  19 } __attribute__((packed));
  20
  21 #endif
  22
  23
  24 int main (void)
  25 {
  26   struct X x;
  27   unsigned int bad_bits;
  28
  29   x.pad = -1;
  30   x.a = -1;
  31   x.b = -1;
  32   x.c = -1;
  33
  34   bad_bits = ((unsigned int)-1) ^ *(1+(unsigned int *) &x);
  35   if (bad_bits != 0)
  36     abort ();
  37   return 0;
  38 }
  39