--- old/src/share/vm/opto/memnode.cpp	2015-09-16 10:30:34.456196540 +0200
+++ new/src/share/vm/opto/memnode.cpp	2015-09-16 10:30:34.158133719 +0200
@@ -2363,6 +2363,16 @@
   return NO_HASH;
 }
 
+#ifdef ASSERT
+static bool maybe_unaligned_store(Node* n) {
+  StoreNode* st = n->as_Store();
+  return st->Opcode() == Op_StoreL ||
+    st->Opcode() == Op_StoreI ||
+    st->Opcode() == Op_StoreB ||
+    st->Opcode() == Op_StoreC;
+}
+#endif
+
 //------------------------------Ideal------------------------------------------
 // Change back-to-back Store(, p, x) -> Store(m, p, y) to Store(m, p, x).
 // When a store immediately follows a relevant allocation/initialization,
@@ -2393,7 +2403,8 @@
              st->Opcode() == Op_StoreVector ||
              Opcode() == Op_StoreVector ||
              phase->C->get_alias_index(adr_type()) == Compile::AliasIdxRaw ||
-             (Opcode() == Op_StoreL && st->Opcode() == Op_StoreI), // expanded ClearArrayNode
+             (Opcode() == Op_StoreL && st->Opcode() == Op_StoreI) || // expanded ClearArrayNode
+             (UseUnalignedAccesses && (maybe_unaligned_store(st) || maybe_unaligned_store(this))),
              err_msg_res("no mismatched stores, except on raw memory: %s %s", NodeClassNames[Opcode()], NodeClassNames[st->Opcode()]));
 
       if (st->in(MemNode::Address)->eqv_uncast(address) &&