diff -r cadca99d52e7 -r a09af8ef8e5c src/hotspot/share/opto/superword.cpp
--- a/src/hotspot/share/opto/superword.cpp	Thu Apr 26 12:39:15 2018 -0700
+++ b/src/hotspot/share/opto/superword.cpp	Thu Apr 26 12:48:35 2018 -0700
@@ -2144,8 +2144,21 @@
     // we use the memory state of the last load. However, if any load could
     // not be moved down due to the dependence constraint, we use the memory
     // state of the first load.
-    Node* last_mem  = executed_last(pk)->in(MemNode::Memory);
-    Node* first_mem = executed_first(pk)->in(MemNode::Memory);
+    Node* first_mem = pk->at(0)->in(MemNode::Memory);
+    Node* last_mem = first_mem;
+    for (uint i = 1; i < pk->size(); i++) {
+      Node* ld = pk->at(i);
+      Node* mem = ld->in(MemNode::Memory);
+      assert(in_bb(first_mem) || in_bb(mem) || mem == first_mem, "2 different memory state from outside the loop?");
+      if (in_bb(mem)) {
+        if (in_bb(first_mem) && bb_idx(mem) < bb_idx(first_mem)) {
+          first_mem = mem;
+        }
+        if (!in_bb(last_mem) || bb_idx(mem) > bb_idx(last_mem)) {
+          last_mem = mem;
+        }
+      }
+    }
     bool schedule_last = true;
     for (uint i = 0; i < pk->size(); i++) {
       Node* ld = pk->at(i);