low_latency.hpp

// Copyright (C) 2021 Intel Corporation
// SPDX-License-Identifier: Apache-2.0
//
 
#pragma once
 
#include <memory>
#include <vector>
 
#include <ngraph/pass/graph_rewrite.hpp>
 
namespace ngraph
{
    namespace pass
    {
        /**
         * @brief The transformation finds all TensorIterator layers in the network,
         * processes all back edges that describe a connection between Result and Parameter
         * of the TensorIterator body,and inserts ReadValue layer between Parameter
         * and the next layers after this Parameter, and Assign layer after the layers
         * before the Result layer. Supported platforms: CPU, GNA.
         *
         * The example below describes the changes to the inner part (body, back edges) of the
         * Tensor Iterator layer.
         *  [] - TensorIterator body
         *  () - new layer
         *
         *  before applying the transformation:
         *  back_edge_1 -> [Parameter -> some layers ... -> Result ] -> back_edge_1
         *
         *  after applying the transformation:
         *  back_edge_1 -> [Parameter -> (ReadValue layer) -> some layers ... -> (Assign layer) ]
         *                                                              \
         *                                                               -> Result ] -> back_edge_1
         *
         * It is recommended to use this transformation in conjunction with the Reshape feature to
         * set  sequence dimension to 1 and with the UnrollTensorIterator transformation.
         * For convenience, we have already enabled the unconditional execution of the
         * UnrollTensorIterator transformation when using the LowLatency transformation for
         * CPU, GNA plugins, no action is required here.
         * After applying both of these transformations, the resulting network can be inferred step
         * by step, the states will store between inferences.
         */
 
        class NGRAPH_API LowLatency : public ngraph::pass::MatcherPass
        {
        public:
            NGRAPH_RTTI_DECLARATION;
            LowLatency();
        };
    } // namespace pass
} // namespace ngraph