1 files changed, 25 insertions, 0 deletions
diff --git a/gcc/testsuite/g++.dg/opt/anonunion1.C b/gcc/testsuite/g++.dg/opt/anonunion1.C
new file mode 100644
index 000000000..445ebaa7c
--- /dev/null
+++ b/gcc/testsuite/g++.dg/opt/anonunion1.C
@@ -0,0 +1,25 @@
+// PR c++/5748
+// This testcase ICEd because used flag from the anon union variables
+// was not propagated back to the anon union itself, causing addressof
+// not to be replaced with stack slot.
+// { dg-do compile }
+// { dg-options "-O2" }
+
+struct A {
+  A ();
+  ~A ();
+  int foo ();
+  int bar (void *x, int y);
+};
+
+int A::foo()
+{
+  union {
+    int a;
+    int b;
+  };
+
+  if (bar (&a, sizeof (int)) != 32)
+    return 16;
+  return 0;
+}