--- a/src/hotspot/share/adlc/adlparse.cpp	Mon Nov 26 12:20:06 2018 -0400
+++ b/src/hotspot/share/adlc/adlparse.cpp	Mon Nov 26 09:36:30 2018 +0100
@@ -2870,7 +2870,8 @@
   const char* param = NULL;
   inst._parameters.reset();
   while ((param = inst._parameters.iter()) != NULL) {
-    OperandForm* opForm = (OperandForm*) inst._localNames[param];
+    OpClassForm* opForm = inst._localNames[param]->is_opclass();
+    assert(opForm != NULL, "sanity");
     encoding->add_parameter(opForm->_ident, param);
   }
 
@@ -3340,7 +3341,8 @@
   const char* param = NULL;
   inst._parameters.reset();
   while ((param = inst._parameters.iter()) != NULL) {
-    OperandForm* opForm = (OperandForm*) inst._localNames[param];
+    OpClassForm* opForm = inst._localNames[param]->is_opclass();
+    assert(opForm != NULL, "sanity");
     encoding->add_parameter(opForm->_ident, param);
   }