gcc/testsuite/gcc.dg/20141029-1.c

   1 /* { dg-do compile } */
   2 /* { dg-options "-fstrict-volatile-bitfields -fdump-rtl-final" } */
   3
   4 #define PERIPH (*(volatile struct system_periph *)0x81234)
   5
   6 struct system_periph {
   7   union {
   8     unsigned short WORD;
   9     struct {
  10       unsigned short a:1;
  11       unsigned short b:1;
  12       unsigned short  :5;
  13       unsigned short c:1;
  14       unsigned short  :8;
  15     } BIT;
  16   } ALL;
  17 } __attribute__((aligned(2)));
  18
  19 void
  20 foo()
  21 {
  22   while (1)
  23     {
  24       PERIPH.ALL.BIT.a = 1;
  25     }
  26 }
  27 /* { dg-final { scan-rtl-dump-times "mem/v(/.)*:HI" 4 "final" } } */