--- a/src/hotspot/cpu/x86/x86_64.ad	Thu Sep 05 12:39:48 2019 +0200
+++ b/src/hotspot/cpu/x86/x86_64.ad	Thu Sep 05 13:56:17 2019 +0200
@@ -7763,6 +7763,17 @@
   ins_pipe(empty);
 %}
 
+instruct castLL(rRegL dst)
+%{
+  match(Set dst (CastLL dst));
+
+  size(0);
+  format %{ "# castLL of $dst" %}
+  ins_encode(/* empty encoding */);
+  ins_cost(0);
+  ins_pipe(empty);
+%}
+
 // LoadP-locked same as a regular LoadP when used with compare-swap
 instruct loadPLocked(rRegP dst, memory mem)
 %{