gcc/testsuite/gcc.dg/pr53352.c

   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 }