1  /* { dg-do run } */
       2  /* { dg-options "-O1" } */
       3  
       4  #include <stdlib.h>
       5  
       6  typedef union
       7  {
       8    struct
       9    {
      10      unsigned char a;
      11      unsigned char b;
      12      unsigned char c;
      13      unsigned char d;
      14    } parts;
      15    unsigned long whole;
      16  } T;
      17  
      18  T *g_t;
      19  
      20  void bar (unsigned long x)
      21  {
      22    if (x != 0)
      23      abort ();
      24  }
      25  
      26  int main ()
      27  {
      28    T one;
      29    T two;
      30    T tmp1, tmp2;
      31  
      32    one.whole = 0xFFE0E0E0UL;
      33    two.whole = 0xFF000000UL;
      34    tmp1.parts = two.parts;
      35    tmp2.parts = one.parts;
      36    tmp2.parts.c = tmp1.parts.c;
      37    one.parts = tmp2.parts;
      38  
      39    g_t = &one;
      40    bar (0);
      41    return 0;
      42  }