1  /* { dg-do compile } */
       2  /* { dg-options "-O2 -fdump-tree-optimized -w" } */
       3  
       4  struct ehci_regs {
       5      char x;
       6      unsigned int port_status[0];
       7  } __attribute__ ((packed));
       8  
       9  struct ehci_hcd {
      10      struct ehci_regs *regs;
      11  };
      12  
      13  int ehci_hub_control (struct ehci_hcd *ehci, int wIndex)
      14  {
      15    unsigned int *status_reg = &ehci->regs->port_status[wIndex];
      16    return *(volatile unsigned int *)status_reg;
      17  }
      18  
      19  /* { dg-final { scan-tree-dump "={v}" "optimized" } } */