src/hotspot/share/interpreter/interpreterRuntime.cpp

*** 733,10 ***
--- 733,19 ---
  // be shared by method invocation and synchronized blocks.
  //%note synchronization_3
  
  //%note monitor_1
  JRT_ENTRY_NO_ASYNC(void, InterpreterRuntime::monitorenter(JavaThread* current, BasicObjectLock* elem))
+   if (!UseHeavyMonitors && UseFastLocking) {
+     // This is a hack to get around the limitation of registers in x86_32. We really
+     // send an oopDesc* instead of a BasicObjectLock*.
+     Handle h_obj(current, oop((reinterpret_cast<oopDesc*>(elem))));
+     assert(Universe::heap()->is_in_or_null(h_obj()),
+            "must be NULL or an object");
+     ObjectSynchronizer::enter(h_obj, NULL, current);
+     return;
+   }
  #ifdef ASSERT
    current->last_frame().interpreter_frame_verify_monitor(elem);
  #endif
    Handle h_obj(current, elem->obj());
    assert(Universe::heap()->is_in_or_null(h_obj()),