1 files changed, 77 insertions, 0 deletions
diff --git a/gcc/testsuite/g++.dg/simulate-thread/bitfields-2.C b/gcc/testsuite/g++.dg/simulate-thread/bitfields-2.C
new file mode 100644
index 00000000000..077514a3ff5
--- /dev/null
+++ b/gcc/testsuite/g++.dg/simulate-thread/bitfields-2.C
@@ -0,0 +1,77 @@
+/* { dg-do link } */
+/* { dg-options "--param allow-load-data-races=0 --param allow-store-data-races=0" } */
+/* { 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;
+}