--- old/src/hotspot/share/c1/c1_LIR.hpp	2019-02-13 17:02:40.051733866 -0800
+++ new/src/hotspot/share/c1/c1_LIR.hpp	2019-02-13 17:02:39.831725560 -0800
@@ -873,6 +873,7 @@
 class    LIR_OpUpdateCRC32;
 class    LIR_OpLock;
 class    LIR_OpTypeCheck;
+class    LIR_OpFlattenedStoreCheck;
 class    LIR_OpCompareAndSwap;
 class    LIR_OpProfileCall;
 class    LIR_OpProfileType;
@@ -987,6 +988,9 @@
     , lir_checkcast
     , lir_store_check
   , end_opTypeCheck
+  , begin_opFlattenedStoreCheck
+    , lir_flattened_store_check
+  , end_opFlattenedStoreCheck
   , begin_opCompareAndSwap
     , lir_cas_long
     , lir_cas_obj
@@ -1137,6 +1141,7 @@
   virtual LIR_OpArrayCopy* as_OpArrayCopy() { return NULL; }
   virtual LIR_OpUpdateCRC32* as_OpUpdateCRC32() { return NULL; }
   virtual LIR_OpTypeCheck* as_OpTypeCheck() { return NULL; }
+  virtual LIR_OpFlattenedStoreCheck* as_OpFlattenedStoreCheck() { return NULL; }
   virtual LIR_OpCompareAndSwap* as_OpCompareAndSwap() { return NULL; }
   virtual LIR_OpProfileCall* as_OpProfileCall() { return NULL; }
   virtual LIR_OpProfileType* as_OpProfileType() { return NULL; }
@@ -1595,6 +1600,34 @@
   void print_instr(outputStream* out) const PRODUCT_RETURN;
 };
 
+// LIR_OpFlattenedStoreCheck
+class LIR_OpFlattenedStoreCheck: public LIR_Op {
+ friend class LIR_OpVisitState;
+
+ private:
+  LIR_Opr       _object;
+  ciKlass*      _element_klass;
+  LIR_Opr       _tmp1;
+  LIR_Opr       _tmp2;
+  CodeEmitInfo* _info_for_exception;
+  CodeStub*     _stub;
+
+public:
+  LIR_OpFlattenedStoreCheck(LIR_Opr object, ciKlass* element_klass, LIR_Opr tmp1, LIR_Opr tmp2,
+                            CodeEmitInfo* info_for_exception);
+
+  LIR_Opr object() const                         { return _object;         }
+  LIR_Opr tmp1() const                           { return _tmp1;           }
+  LIR_Opr tmp2() const                           { return _tmp2;           }
+  ciKlass* element_klass() const                 { return _element_klass;  }
+  CodeEmitInfo* info_for_exception() const       { return _info_for_exception; }
+  CodeStub* stub() const                         { return _stub;           }
+
+  virtual void emit_code(LIR_Assembler* masm);
+  virtual LIR_OpFlattenedStoreCheck* as_OpFlattenedStoreCheck() { return this; }
+  virtual void print_instr(outputStream* out) const PRODUCT_RETURN;
+};
+
 // LIR_Op2
 class LIR_Op2: public LIR_Op {
  friend class LIR_OpVisitState;
@@ -2252,6 +2285,7 @@
 
   void instanceof(LIR_Opr result, LIR_Opr object, ciKlass* klass, LIR_Opr tmp1, LIR_Opr tmp2, LIR_Opr tmp3, bool fast_check, CodeEmitInfo* info_for_patch, ciMethod* profiled_method, int profiled_bci);
   void store_check(LIR_Opr object, LIR_Opr array, LIR_Opr tmp1, LIR_Opr tmp2, LIR_Opr tmp3, CodeEmitInfo* info_for_exception, ciMethod* profiled_method, int profiled_bci);
+  void flattened_store_check(LIR_Opr object, ciKlass* element_klass, LIR_Opr tmp1, LIR_Opr tmp2, CodeEmitInfo* info_for_exception);
 
   void checkcast (LIR_Opr result, LIR_Opr object, ciKlass* klass,
                   LIR_Opr tmp1, LIR_Opr tmp2, LIR_Opr tmp3, bool fast_check,