gcc/testsuite/gcc.dg/gomp/appendix-a/a.17.1.c

   1 /* { dg-do compile } */
   2
   3 void
   4 a17_1_wrong ()
   5 {
   6   union
   7   {
   8     int n;
   9     float x;
  10   } u;
  11 #pragma omp parallel
  12   {
  13 #pragma omp atomic
  14     u.n++;
  15 #pragma omp atomic
  16     u.x += 1.0;
  17 /* Incorrect because the atomic constructs reference the same location
  18      through incompatible types */
  19   }
  20 }