output.
### `-tf-tpu-host-computation-expansion`

_Expands host computation before and after TPU computation._

This pass expands outside compilation attributes to Identity/Cast ops
at the head of TPU computation if it's only used by outside compiled ops.
### `-tf-tpu-identity-pruning`

_Removes Identity/IdentityN ops from the TPU computation_

### `-tf-tpu-merge-variables-with-execute`

    }
  }
}

// Since we have the outputs from host and device computation after moving
// outside compiled ops, we can create the actual parallel_execute regions.
// Still, one region is for the host computation for outside compilation and
// the other one is for the original Device cluster computation.
mlir::tf_device::ParallelExecuteOp CreateFinalParallelExecuteOp(

  let summary = "Op that compiles a computation in MLIR into a TPU program, and loads and executes it on a TPU device.";

  let description = [{
For the internal use of the TPU compiler.

'static_shapes' are tensors specifying the maximum dimension sizes for the tensors specified in `dynamic_operands`.
'args' are inputs to the TPU computation.

// 2) Any resource stores except the last one.
// TODO(ycao): Store-load forwarding implemented here is only correct when
// computation is purely sequential (no concurrency). Need to support concurrent
// computation as well.
void ForwardStoreToLoad(Block* block) {
  // resource_handle_to_last_store_op keeps track of the most recent (last)

   * computation is {@linkplain java.util.concurrent.Future#isDone() complete} or, if the
   * computation is already complete, immediately.
   *
   * <p>The callback is run on {@code executor}. There is no guaranteed ordering of execution of
   * callbacks, but any callback added through this method is guaranteed to be called once the
   * computation is complete.
   *

   * computation is {@linkplain java.util.concurrent.Future#isDone() complete} or, if the
   * computation is already complete, immediately.
   *
   * <p>The callback is run on {@code executor}. There is no guaranteed ordering of execution of
   * callbacks, but any callback added through this method is guaranteed to be called once the
   * computation is complete.
   *

  FunctionLibraryDefinition flib_def(graph->op_registry(), flib);
  TF_ASSERT_OK(
      MarkForCompilationPassTestHelper::MarkForCompilation(&graph, &flib_def));
  auto clusters = GetClusters(*graph);

  // The computation is: C = A + relu(A)
  // where A sits in ScopeA, relu(A) sits in ScopeB, and C sits in ScopeC.
  // In this case, the GlobalJitLevel overrides the scopes to cluster while
  // ignoring scopes.

        //   ApplyWeightUpdates_2 -> "iteration++"
        //   ApplyWeightUpdates_0 -> Computation_A
        //   ApplyWeightUpdates_1 -> Computation_B
        //   ApplyWeightUpdates_2 -> Computation_C
        //   Computation_A -> NoOp
        //   Computation_B -> NoOp
        //   Computation_C -> NoOp
        //   "iteration++" -> NoOp
        // }
        //

// suggest a representation, namely using 1-1-1 00:00:00 UTC as the
// epoch, and that's what we do.
//
// The Add and Sub computations are oblivious to the choice of epoch.
//
// The presentation computations - year, month, minute, and so on - all
// rely heavily on division and modulus by positive constants. For
// calendrical calculations we want these divisions to round down, even

 * java.util.concurrent.Executor) Futures.catching}.
 *
 * <p>This class implements all methods in {@code ListenableFuture}. Subclasses should provide a way
 * to set the result of the computation through the protected methods {@link #set(Object)}, {@link
 * #setFuture(ListenableFuture)} and {@link #setException(Throwable)}. Subclasses may also override