--- a/hotspot/src/share/vm/opto/stringopts.cpp	Thu Nov 19 16:07:22 2015 -0800
+++ b/hotspot/src/share/vm/opto/stringopts.cpp	Fri Nov 20 10:09:42 2015 +0100
@@ -1293,7 +1293,7 @@
   Node* index = __ SubI(charPos, __ intcon((bt == T_BYTE) ? 1 : 2));
   Node* ch = __ AddI(r, __ intcon('0'));
   Node* st = __ store_to_memory(kit.control(), kit.array_element_address(dst_array, index, T_BYTE),
-                                ch, bt, byte_adr_idx, MemNode::unordered);
+                                ch, bt, byte_adr_idx, MemNode::unordered, (bt != T_BYTE) /* mismatched */);
 
   iff = kit.create_and_map_if(head, __ Bool(__ CmpI(q, __ intcon(0)), BoolTest::ne),
                               PROB_FAIR, COUNT_UNKNOWN);
@@ -1331,7 +1331,7 @@
   } else {
     Node* index = __ SubI(charPos, __ intcon((bt == T_BYTE) ? 1 : 2));
     st = __ store_to_memory(kit.control(), kit.array_element_address(dst_array, index, T_BYTE),
-                            sign, bt, byte_adr_idx, MemNode::unordered);
+                            sign, bt, byte_adr_idx, MemNode::unordered, (bt != T_BYTE) /* mismatched */);
 
     final_merge->init_req(merge_index + 1, kit.control());
     final_mem->init_req(merge_index + 1, st);
@@ -1524,7 +1524,7 @@
       } else {
         val = readChar(src_array, i++);
       }
-      __ store(__ ctrl(), adr, __ ConI(val), T_CHAR, byte_adr_idx, MemNode::unordered);
+      __ store(__ ctrl(), adr, __ ConI(val), T_CHAR, byte_adr_idx, MemNode::unordered, true /* mismatched */);
       index = __ AddI(index, __ ConI(2));
     }
     if (src_is_byte) {
@@ -1612,7 +1612,7 @@
   }
   if (!dcon || !dbyte) {
     // Destination is UTF16. Store a char.
-    __ store(__ ctrl(), adr, val, T_CHAR, byte_adr_idx, MemNode::unordered);
+    __ store(__ ctrl(), adr, val, T_CHAR, byte_adr_idx, MemNode::unordered, true /* mismatched */);
     __ set(end, __ AddI(start, __ ConI(2)));
   }
   if (!dcon) {