--- old/src/hotspot/share/opto/split_if.cpp	2019-03-11 14:26:57.778354441 +0100
+++ new/src/hotspot/share/opto/split_if.cpp	2019-03-11 14:26:57.530354445 +0100
@@ -27,6 +27,7 @@
 #include "opto/callnode.hpp"
 #include "opto/loopnode.hpp"
 #include "opto/movenode.hpp"
+#include "opto/valuetypenode.hpp"
 
 
 //------------------------------split_thru_region------------------------------
@@ -231,6 +232,15 @@
     rtype = TypeLong::INT;
   }
 
+  // Value types should not be split through Phis but each value input
+  // needs to be merged individually. At this point, value types should
+  // only be used by AllocateNodes. Try to remove redundant allocations
+  // and unlink the now dead value type node.
+  if (n->is_ValueType()) {
+    n->as_ValueType()->remove_redundant_allocations(&_igvn, this);
+    return true; // n is now dead
+  }
+
   // Now actually split-up this guy.  One copy per control path merging.
   Node *phi = PhiNode::make_blank(blk1, n);
   for( uint j = 1; j < blk1->req(); j++ ) {