diff -r 5865398439d4 -r d7df2dd501ce src/hotspot/share/interpreter/interpreterRuntime.cpp
--- a/src/hotspot/share/interpreter/interpreterRuntime.cpp	Wed Mar 21 17:09:34 2018 -0400
+++ b/src/hotspot/share/interpreter/interpreterRuntime.cpp	Wed Mar 21 19:45:24 2018 -0400
@@ -53,6 +53,7 @@
 #include "runtime/compilationPolicy.hpp"
 #include "runtime/deoptimization.hpp"
 #include "runtime/fieldDescriptor.hpp"
+#include "runtime/frame.inline.hpp"
 #include "runtime/handles.inline.hpp"
 #include "runtime/icache.hpp"
 #include "runtime/interfaceSupport.inline.hpp"
@@ -84,6 +85,58 @@
     }
 };
 
+// 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)
+  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)); }
+
+  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; }
+};
+
+
+bool InterpreterRuntime::is_breakpoint(JavaThread *thread) {
+  return Bytecodes::code_or_bp_at(LastFrameAccessor(thread).bcp()) == Bytecodes::_breakpoint;
+}
+
 //------------------------------------------------------------------------------------------------------------------------
 // State accessors