// CHECK-NEXT: [[RES:%.*]] = "tf.Sub"({{%.*}}, [[V]])
// CHECK: "tf_mlrt.tf_promise"([[PROMISE]], [[RES]])
// CHECK: return

// CHECK-LABEL: func private @main_stream_{{[0-9]*}}
// CHECK-SAME: ([[CONTROL_FUTURE:%.*]]: !mlrt.future, [[PROMISE:%.*]]: !mlrt.promise, [[PROMISE_HANDLE:%.*]]: !mlrt.promise)
// CHECK: [[HANDLE:%.*]] = "tf.VarHandleOp"
// CHECK-NEXT: "tf_mlrt.tf_promise"([[PROMISE_HANDLE]], [[HANDLE]])

// CHECK-NEXT:    "tf_mlrt.tf_promise"(%arg2, %1) : (!mlrt.promise, tensor<i32>) -> ()
// CHECK-NEXT:    %2 = "tf.PartitionedCall"(%1, %arg5) <{config = "", config_proto = "", executor_type = "", f = @"map/while_cond/TfMlrtAsyncWhilePredicate"}> : (tensor<i32>, tensor<i32>) -> tensor<i1>
// CHECK-NEXT:    "tf_mlrt.tf_promise"(%arg0, %2) : (!mlrt.promise, tensor<i1>) -> ()

  // CHECK: tf_mlrt.promise [[promise_c]], [[c]]
  "tf_mlrt.tf_promise"(%promise_c, %c) : (!mlrt.promise, tensor<i32>) -> ()
  // CHECK: [[d:%.*]] = tf_mlrt.executeop([[c]])
  // CHECK-SAME: Abs
  %d = "tf.Abs"(%c) {__op_key = 5: i32}: (tensor<i32>) -> tensor<i32>
  // CHECK: tf_mlrt.promise [[promise_d]], [[d]]
  "tf_mlrt.tf_promise"(%promise_d, %d) : (!mlrt.promise, tensor<i32>) -> ()
  // CHECK: return
  return
}

  let arguments = (ins
    MlrtFutureType:$future
  );

  let results = (outs
    TF_Tensor:$result
  );
}

// tf_mlrt.tf_promise takes a tensorflow Tensor. It is a fake op that is only
// used during parallelization and has no runtime implementation.
def TFPromiseOp: TensorflowMlrt_Op<"tf_promise", [TF_MustExecute, TFRT_CostFunctionInterface, TFRT_FixedCost<1>]> {
  let summary = "Set a tensor in a promise";

  let description = [{

// CHECK-NEXT: tf.Mul
// CHECK-NEXT: tf_mlrt.tf_await
// CHECK-NEXT: tf_mlrt.tf_await
// CHECK-NEXT: tf.TensorListSetItem
// CHECK-NEXT: tf.TensorListSetItem
// CHECK-NEXT: tf_mlrt.tf_promise
// CHECK-NEXT: tf_mlrt.tf_promise
// CHECK-NEXT: return

// CHECK-LABEL: tf.MultiListWhileRegion_cond