message: Add the reference versions of control ops
diff: @@ -78,10 +78,15 @@ REGISTER_XLA_OP(Name("ArgMax")
  .CompileTimeConstInput("dimension"), XlaArgMaxOp);
  REGISTER_XLA_OP(Name("Enter").Device(DEVICE_IPU_XLA_JIT), NoOp);
  +REGISTER_XLA_OP(Name("RefEnter").Device(DEVICE_IPU_XLA_JIT), NoOp);
  REGISTER_XLA_OP(Name("Exit").Device(DEVICE_IPU_XLA_JIT), NoOp);
  +REGISTER_XLA_OP(Name("RefExit").Device(DEVICE_IPU_XLA_JIT), NoOp);
  REGISTER_XLA_OP(Name("LoopCond").Device(DEVICE_IPU_XLA_JIT), NoOp);
  REGISTER_XLA_OP(Name("Merge").Device(DEVICE_IPU_XLA_JIT), NoOp);
  +REGISTER_XLA_OP(Name("RefMerge").Device(DEVICE_IPU_XLA_JIT), NoOp);
  REGISTER_XLA_OP(Name("NextIteration").Device(DEVICE_IPU_XLA_JIT), NoOp);
  +REGISTER_XLA_OP(Name("RefNextIteration").Device(DEVICE_IPU_XLA_JIT), NoOp);
  REGISTER_XLA_OP(Name("Switch").Device(DEVICE_IPU_XLA_JIT), NoOp);
  +REGISTER_XLA_OP(Name("RefSwitch").Device(DEVICE_IPU_XLA_JIT), NoOp);
  } // namespace tensorflow
  