1 files changed, 36 insertions, 0 deletions
diff --git a/gcc/testsuite/g++.dg/ext/alias-canon2.C b/gcc/testsuite/g++.dg/ext/alias-canon2.C
new file mode 100644
index 000000000..4833db852
--- /dev/null
+++ b/gcc/testsuite/g++.dg/ext/alias-canon2.C
@@ -0,0 +1,36 @@
+// { dg-do compile }
+// PR c++/37553
+typedef unsigned int ui32;
+__extension__ typedef unsigned long long int ui64;
+
+typedef ui32 __attribute__ ((__may_alias__)) ui32a;
+typedef ui64 __attribute__ ((__may_alias__)) ui64a;
+
+union u_u32
+{
+  ui32a v;
+} __attribute__ ((__may_alias__));
+
+union u_u64
+{
+  ui64a v;
+  struct
+  {
+    union u_u32 lo32, hi32;
+  } u;
+} __attribute__ ((__may_alias__));
+
+void
+out_long (ui64 longVal)
+{
+  if ((*(union u_u64 *) &longVal).u.lo32.v < 0x10000000ul)
+    {
+      if ((ui32) ((*(union u_u64 *) &longVal).u.lo32.v) < 0x4000u)
+        {
+          /* do something useful */
+        }
+    }
+}
+
+void f(ui32 *) { }
+void f(ui32a *) { }