gcc/testsuite/gcc.dg/pr45819.c

   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" } } */