Corrected form of https://gcc.gnu.org/bugzilla/show_bug.cgi?

#include <stdlib.h>
#include <stdio.h>

union Alias {
int pi;
double pd;
};

int main()
{
  void *p = malloc(10);
  union Alias* alias = p;

  alias->pi = 1;
  printf("*pi = %d\n", alias->pi);

  int a = alias->pi;
  alias->pd = 0;
  alias->pi = a;

  printf("p = %p\n", p);
  printf("*pi = %d\n", alias->pi);
}