gcc/testsuite/g++.dg/simulate-thread/bitfields-2.C

/* { dg-do link } */
/* { dg-options "-fno-allow-store-data-races" } */
/* { dg-final { simulate-thread } } */

/* Test that setting <var.a> does not touch either <var.b> or <var.c>.
   In the C++ memory model, non contiguous bitfields ("a" and "c"
   here) should be considered as distinct memory locations, so we
   can't use bit twiddling to set either one.  */

#include <stdio.h>
#include "simulate-thread.h"

#define CONSTA 12

static int global;
struct S
{
  unsigned int a : 4;
  unsigned char b;
  unsigned int c : 6;
} var;

__attribute__((noinline))
void set_a()
{
  var.a = CONSTA;
}

void simulate_thread_other_threads()
{
  ++global;
  var.b = global;
  var.c = global;
}

int simulate_thread_step_verify()
{
  int ret = 0;
  if (var.b != global)
    {
      printf ("FAIL: Unexpected value: var.b is %d, should be %d\n",
	      var.b, global);
      ret = 1;
    }
  if (var.c != global)
    {
      printf ("FAIL: Unexpected value: var.c is %d, should be %d\n",
	      var.c, global);
      ret = 1;
    }
  return ret;
}

int simulate_thread_final_verify()
{
  int ret = simulate_thread_step_verify();
  if (var.a != CONSTA)
    {
      printf ("FAIL: Unexpected value: var.a is %d, should be %d\n",
	      var.a, CONSTA);
      ret = 1;
    }
  return ret;
}

__attribute__((noinline))
void simulate_thread_main()
{
  set_a();
}

int main()
{
  simulate_thread_main();
  simulate_thread_done();
  return 0;
}