if (verboseJNI) VM.sysWrite("JNI called: IsInstanceOf  \n");
if (traceJNI) VM.sysWrite("JNI called: IsInstanceOf  \n");
  private static int IsInstanceOf(int envJREF, int objJREF, int classJREF) {    if (verboseJNI) VM.sysWrite("JNI called: IsInstanceOf  \n");    VM_JNIEnvironment env;    try {      env = VM_Thread.getCurrentThread().getJNIEnv();      Class cls = (Class) env.getJNIRef(classJREF);      Object obj = (Object) env.getJNIRef(objJREF);      if (VM_Runtime.instanceOf(obj, java.lang.JikesRVMSupport.getTypeForClass(cls).getTibOffset()))        return 1;      else         return 0;    } catch (Throwable unexpected) {      env = VM_Thread.getCurrentThread().getJNIEnv();      env.recordException(unexpected);      return 0;    }  }