--- a/src/hotspot/share/interpreter/interpreterRuntime.hpp	Wed Nov 01 19:43:13 2017 -0400
+++ b/src/hotspot/share/interpreter/interpreterRuntime.hpp	Thu Oct 26 11:35:09 2017 -0700
@@ -42,29 +42,54 @@
   friend class PrintingClosure; // for method and bcp
 
  private:
-  // Helper functions to access current interpreter state
-  static frame     last_frame(JavaThread *thread)    { return thread->last_frame(); }
-  static Method*   method(JavaThread *thread)        { return last_frame(thread).interpreter_frame_method(); }
-  static address   bcp(JavaThread *thread)           { return last_frame(thread).interpreter_frame_bcp(); }
-  static int       bci(JavaThread *thread)           { return last_frame(thread).interpreter_frame_bci(); }
-  static void      set_bcp_and_mdp(address bcp, JavaThread*thread);
-  static Bytecodes::Code code(JavaThread *thread)    {
+  // Helper class to access current interpreter state
+  class LastFrameAccessor : public StackObj {
+    frame _last_frame;
+  public:
+    LastFrameAccessor(JavaThread* thread) {
+      assert(thread == Thread::current(), "sanity");
+      _last_frame = thread->last_frame();
+    }
+    bool is_interpreted_frame() const              { return _last_frame.is_interpreted_frame(); }
+    Method*   method() const                       { return _last_frame.interpreter_frame_method(); }
+    address   bcp() const                          { return _last_frame.interpreter_frame_bcp(); }
+    int       bci() const                          { return _last_frame.interpreter_frame_bci(); }
+    address   mdp() const                          { return _last_frame.interpreter_frame_mdp(); }
+
+    void      set_bcp(address bcp)                 { _last_frame.interpreter_frame_set_bcp(bcp); }
+    void      set_mdp(address dp)                  { _last_frame.interpreter_frame_set_mdp(dp); }
+
     // pass method to avoid calling unsafe bcp_to_method (partial fix 4926272)
-    return Bytecodes::code_at(method(thread), bcp(thread));
-  }
-  static Bytecode  bytecode(JavaThread *thread)      { return Bytecode(method(thread), bcp(thread)); }
-  static int       get_index_u1(JavaThread *thread, Bytecodes::Code bc)
-                                                        { return bytecode(thread).get_index_u1(bc); }
-  static int       get_index_u2(JavaThread *thread, Bytecodes::Code bc)
-                                                        { return bytecode(thread).get_index_u2(bc); }
-  static int       get_index_u2_cpcache(JavaThread *thread, Bytecodes::Code bc)
-                                                        { return bytecode(thread).get_index_u2_cpcache(bc); }
-  static int       get_index_u4(JavaThread *thread, Bytecodes::Code bc)
-                                                        { return bytecode(thread).get_index_u4(bc); }
-  static int       number_of_dimensions(JavaThread *thread)  { return bcp(thread)[3]; }
+    Bytecodes::Code code() const                   { return Bytecodes::code_at(method(), bcp()); }
+
+    Bytecode  bytecode() const                     { return Bytecode(method(), bcp()); }
+    int get_index_u1(Bytecodes::Code bc) const     { return bytecode().get_index_u1(bc); }
+    int get_index_u2(Bytecodes::Code bc) const     { return bytecode().get_index_u2(bc); }
+    int get_index_u2_cpcache(Bytecodes::Code bc) const
+                                                   { return bytecode().get_index_u2_cpcache(bc); }
+    int get_index_u4(Bytecodes::Code bc) const     { return bytecode().get_index_u4(bc); }
+    int number_of_dimensions() const               { return bcp()[3]; }
+    ConstantPoolCacheEntry* cache_entry_at(int i) const
+                                                   { return method()->constants()->cache()->entry_at(i); }
+    ConstantPoolCacheEntry* cache_entry() const    { return cache_entry_at(Bytes::get_native_u2(bcp() + 1)); }
 
-  static ConstantPoolCacheEntry* cache_entry_at(JavaThread *thread, int i)  { return method(thread)->constants()->cache()->entry_at(i); }
-  static ConstantPoolCacheEntry* cache_entry(JavaThread *thread)            { return cache_entry_at(thread, Bytes::get_native_u2(bcp(thread) + 1)); }
+    oop callee_receiver(Symbol* signature) {
+      return _last_frame.interpreter_callee_receiver(signature);
+    }
+    BasicObjectLock* monitor_begin() const {
+      return _last_frame.interpreter_frame_monitor_begin();
+    }
+    BasicObjectLock* monitor_end() const {
+      return _last_frame.interpreter_frame_monitor_end();
+    }
+    BasicObjectLock* next_monitor(BasicObjectLock* current) const {
+      return _last_frame.next_monitor_in_interpreter_frame(current);
+    }
+
+    frame& get_frame()                             { return _last_frame; }
+  };
+
+  static void      set_bcp_and_mdp(address bcp, JavaThread*thread);
   static void      note_trap_inner(JavaThread* thread, int reason,
                                    const methodHandle& trap_method, int trap_bci, TRAPS);
   static void      note_trap(JavaThread *thread, int reason, TRAPS);
@@ -139,7 +164,7 @@
   static void _breakpoint(JavaThread* thread, Method* method, address bcp);
   static Bytecodes::Code get_original_bytecode_at(JavaThread* thread, Method* method, address bcp);
   static void            set_original_bytecode_at(JavaThread* thread, Method* method, address bcp, Bytecodes::Code new_code);
-  static bool is_breakpoint(JavaThread *thread) { return Bytecodes::code_or_bp_at(bcp(thread)) == Bytecodes::_breakpoint; }
+  static bool is_breakpoint(JavaThread *thread) { return Bytecodes::code_or_bp_at(LastFrameAccessor(thread).bcp()) == Bytecodes::_breakpoint; }
 
   // Safepoints
   static void    at_safepoint(JavaThread* thread);