--- a/src/hotspot/share/opto/gcm.cpp	Fri Jul 13 11:21:55 2018 +0800
+++ b/src/hotspot/share/opto/gcm.cpp	Thu Jul 12 16:31:28 2018 +0200
@@ -1263,6 +1263,7 @@
         Node* use = self->fast_out(i);
         LCA = raise_LCA_above_use(LCA, use, self, this);
       }
+      guarantee(LCA != NULL, "There must be a LCA");
     }  // (Hide defs of imax, i from rest of block.)
 
     // Place temps in the block of their use.  This isn't a