Intel® oneAPI Deep Neural Network Developer Guide and Reference
                    
                        ID
                        768875
                    
                
                
                    Date
                    2/28/2024
                
                
                    Public
                
            A newer version of this document is available. Customers should click here to go to the newest version.
                                                
                                                
                                                    
                                                    
                                                        Abs
                                                    
                                                    
                                                
                                                    
                                                    
                                                        AbsBackward
                                                    
                                                    
                                                
                                                    
                                                    
                                                        Add
                                                    
                                                    
                                                
                                                    
                                                    
                                                        AvgPool
                                                    
                                                    
                                                
                                                    
                                                    
                                                        AvgPoolBackward
                                                    
                                                    
                                                
                                                    
                                                    
                                                        BatchNormForwardTraining
                                                    
                                                    
                                                
                                                    
                                                    
                                                        BatchNormInference
                                                    
                                                    
                                                
                                                    
                                                    
                                                        BatchNormTrainingBackward
                                                    
                                                    
                                                
                                                    
                                                    
                                                        BiasAdd
                                                    
                                                    
                                                
                                                    
                                                    
                                                        BiasAddBackward
                                                    
                                                    
                                                
                                                    
                                                    
                                                        Clamp
                                                    
                                                    
                                                
                                                    
                                                    
                                                        ClampBackward
                                                    
                                                    
                                                
                                                    
                                                    
                                                        Concat
                                                    
                                                    
                                                
                                                    
                                                    
                                                        Convolution
                                                    
                                                    
                                                
                                                    
                                                    
                                                        ConvolutionBackwardData
                                                    
                                                    
                                                
                                                    
                                                    
                                                        ConvolutionBackwardWeights
                                                    
                                                    
                                                
                                                    
                                                    
                                                        ConvTranspose
                                                    
                                                    
                                                
                                                    
                                                    
                                                        ConvTransposeBackwardData
                                                    
                                                    
                                                
                                                    
                                                    
                                                        ConvTransposeBackwardWeights
                                                    
                                                    
                                                
                                                    
                                                    
                                                        Dequantize
                                                    
                                                    
                                                
                                                    
                                                    
                                                        Divide
                                                    
                                                    
                                                
                                                    
                                                    
                                                        DynamicDequantize
                                                    
                                                    
                                                
                                                    
                                                    
                                                        DynamicQuantize
                                                    
                                                    
                                                
                                                    
                                                    
                                                        Elu
                                                    
                                                    
                                                
                                                    
                                                    
                                                        EluBackward
                                                    
                                                    
                                                
                                                    
                                                    
                                                        End
                                                    
                                                    
                                                
                                                    
                                                    
                                                        Exp
                                                    
                                                    
                                                
                                                    
                                                    
                                                        GELU
                                                    
                                                    
                                                
                                                    
                                                    
                                                        GELUBackward
                                                    
                                                    
                                                
                                                    
                                                    
                                                        HardSigmoid
                                                    
                                                    
                                                
                                                    
                                                    
                                                        HardSigmoidBackward
                                                    
                                                    
                                                
                                                    
                                                    
                                                        HardSwish
                                                    
                                                    
                                                
                                                    
                                                    
                                                        HardSwishBackward
                                                    
                                                    
                                                
                                                    
                                                    
                                                        Interpolate
                                                    
                                                    
                                                
                                                    
                                                    
                                                        InterpolateBackward
                                                    
                                                    
                                                
                                                    
                                                    
                                                        LayerNorm
                                                    
                                                    
                                                
                                                    
                                                    
                                                        LayerNormBackward
                                                    
                                                    
                                                
                                                    
                                                    
                                                        LeakyReLU
                                                    
                                                    
                                                
                                                    
                                                    
                                                        Log
                                                    
                                                    
                                                
                                                    
                                                    
                                                        LogSoftmax
                                                    
                                                    
                                                
                                                    
                                                    
                                                        LogSoftmaxBackward
                                                    
                                                    
                                                
                                                    
                                                    
                                                        MatMul
                                                    
                                                    
                                                
                                                    
                                                    
                                                        Maximum
                                                    
                                                    
                                                
                                                    
                                                    
                                                        MaxPool
                                                    
                                                    
                                                
                                                    
                                                    
                                                        MaxPoolBackward
                                                    
                                                    
                                                
                                                    
                                                    
                                                        Minimum
                                                    
                                                    
                                                
                                                    
                                                    
                                                        Mish
                                                    
                                                    
                                                
                                                    
                                                    
                                                        MishBackward
                                                    
                                                    
                                                
                                                    
                                                    
                                                        Multiply
                                                    
                                                    
                                                
                                                    
                                                    
                                                        Pow
                                                    
                                                    
                                                
                                                    
                                                    
                                                        PReLU
                                                    
                                                    
                                                
                                                    
                                                    
                                                        PReLUBackward
                                                    
                                                    
                                                
                                                    
                                                    
                                                        Quantize
                                                    
                                                    
                                                
                                                    
                                                    
                                                        Reciprocal
                                                    
                                                    
                                                
                                                    
                                                    
                                                        ReduceL1
                                                    
                                                    
                                                
                                                    
                                                    
                                                        ReduceL2
                                                    
                                                    
                                                
                                                    
                                                    
                                                        ReduceMax
                                                    
                                                    
                                                
                                                    
                                                    
                                                        ReduceMean
                                                    
                                                    
                                                
                                                    
                                                    
                                                        ReduceMin
                                                    
                                                    
                                                
                                                    
                                                    
                                                        ReduceProd
                                                    
                                                    
                                                
                                                    
                                                    
                                                        ReduceSum
                                                    
                                                    
                                                
                                                    
                                                    
                                                        ReLU
                                                    
                                                    
                                                
                                                    
                                                    
                                                        ReLUBackward
                                                    
                                                    
                                                
                                                    
                                                    
                                                        Reorder
                                                    
                                                    
                                                
                                                    
                                                    
                                                        Round
                                                    
                                                    
                                                
                                                    
                                                    
                                                        Select
                                                    
                                                    
                                                
                                                    
                                                    
                                                        Sigmoid
                                                    
                                                    
                                                
                                                    
                                                    
                                                        SigmoidBackward
                                                    
                                                    
                                                
                                                    
                                                    
                                                        SoftMax
                                                    
                                                    
                                                
                                                    
                                                    
                                                        SoftMaxBackward
                                                    
                                                    
                                                
                                                    
                                                    
                                                        SoftPlus
                                                    
                                                    
                                                
                                                    
                                                    
                                                        SoftPlusBackward
                                                    
                                                    
                                                
                                                    
                                                    
                                                        Sqrt
                                                    
                                                    
                                                
                                                    
                                                    
                                                        SqrtBackward
                                                    
                                                    
                                                
                                                    
                                                    
                                                        Square
                                                    
                                                    
                                                
                                                    
                                                    
                                                        SquaredDifference
                                                    
                                                    
                                                
                                                    
                                                    
                                                        StaticReshape
                                                    
                                                    
                                                
                                                    
                                                    
                                                        StaticTranspose
                                                    
                                                    
                                                
                                                    
                                                    
                                                        Subtract
                                                    
                                                    
                                                
                                                    
                                                    
                                                        Tanh
                                                    
                                                    
                                                
                                                    
                                                    
                                                        TanhBackward
                                                    
                                                    
                                                
                                                    
                                                    
                                                        TypeCast
                                                    
                                                    
                                                
                                                    
                                                    
                                                        Wildcard
                                                    
                                                    
                                                
                                            
                                        
                                                            
                                                            
                                                                
                                                                
                                                                    enum dnnl_alg_kind_t
                                                                
                                                                
                                                            
                                                                
                                                                
                                                                    enum dnnl_normalization_flags_t
                                                                
                                                                
                                                            
                                                                
                                                                
                                                                    enum dnnl_primitive_kind_t
                                                                
                                                                
                                                            
                                                                
                                                                
                                                                    enum dnnl_prop_kind_t
                                                                
                                                                
                                                            
                                                                
                                                                
                                                                    enum dnnl_query_t
                                                                
                                                                
                                                            
                                                                
                                                                
                                                                    enum dnnl::normalization_flags
                                                                
                                                                
                                                            
                                                                
                                                                
                                                                    enum dnnl::query
                                                                
                                                                
                                                            
                                                                
                                                                
                                                                    struct dnnl_exec_arg_t
                                                                
                                                                
                                                            
                                                                
                                                                
                                                                    struct dnnl_primitive
                                                                
                                                                
                                                            
                                                                
                                                                
                                                                    struct dnnl_primitive_desc
                                                                
                                                                
                                                            
                                                                
                                                                    struct dnnl::primitive
                                                                
                                                                
                                                                
                                                            
                                                                
                                                                
                                                                    struct dnnl::primitive_desc
                                                                
                                                                
                                                            
                                                                
                                                                
                                                                    struct dnnl::primitive_desc_base
                                                                
                                                                
                                                            
                                                        
                                                    
                                                            
                                                            
                                                                
                                                                
                                                                    enum dnnl_rnn_direction_t
                                                                
                                                                
                                                            
                                                                
                                                                
                                                                    enum dnnl_rnn_flags_t
                                                                
                                                                
                                                            
                                                                
                                                                
                                                                    enum dnnl::rnn_direction
                                                                
                                                                
                                                            
                                                                
                                                                
                                                                    enum dnnl::rnn_flags
                                                                
                                                                
                                                            
                                                                
                                                                    struct dnnl::augru_backward
                                                                
                                                                
                                                                
                                                            
                                                                
                                                                    struct dnnl::augru_forward
                                                                
                                                                
                                                                
                                                            
                                                                
                                                                    struct dnnl::gru_backward
                                                                
                                                                
                                                                
                                                            
                                                                
                                                                    struct dnnl::gru_forward
                                                                
                                                                
                                                                
                                                            
                                                                
                                                                    struct dnnl::lbr_augru_backward
                                                                
                                                                
                                                                
                                                            
                                                                
                                                                    struct dnnl::lbr_augru_forward
                                                                
                                                                
                                                                
                                                            
                                                                
                                                                    struct dnnl::lbr_gru_backward
                                                                
                                                                
                                                                
                                                            
                                                                
                                                                    struct dnnl::lbr_gru_forward
                                                                
                                                                
                                                                
                                                            
                                                                
                                                                    struct dnnl::lstm_backward
                                                                
                                                                
                                                                
                                                            
                                                                
                                                                    struct dnnl::lstm_forward
                                                                
                                                                
                                                                
                                                            
                                                                
                                                                
                                                                    struct dnnl::rnn_primitive_desc_base
                                                                
                                                                
                                                            
                                                                
                                                                    struct dnnl::vanilla_rnn_backward
                                                                
                                                                
                                                                
                                                            
                                                                
                                                                    struct dnnl::vanilla_rnn_forward
                                                                
                                                                
                                                                
                                                            
                                                        
                                                    rnn_training_f32 cpp
This C++ API example demonstrates how to build GNMT model training. Annotated version: RNN f32 training example
This C++ API example demonstrates how to build GNMT model training. Annotated version: RNN f32 training example
/*******************************************************************************
* Copyright 2018-2022 Intel Corporation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*     http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*******************************************************************************/
#include <cstring>
#include <math.h>
#include <numeric>
#include <utility>
#include "oneapi/dnnl/dnnl.hpp"
#include "example_utils.hpp"
using namespace dnnl;
// User input is:
//     N0 sequences of length T0
const int N0 = 1 + rand() % 31;
//     N1 sequences of length T1
const int N1 = 1 + rand() % 31;
// Assume T0 > T1
const int T0 = 31 + 1 + rand() % 31;
const int T1 = 1 + rand() % 31;
// Memory required to hold it: N0 * T0 + N1 * T1
// However it is possible to have these coming
// as padded chunks in larger memory:
//      e.g. (N0 + N1) * T0
// We don't need to compact the data before processing,
// we can address the chunks via sub-memory and
// process the data via two RNN primitives:
//     of time lengths T1 and T0 - T1.
// The leftmost primitive will process N0 + N1 subsequences of length T1
// The rightmost primitive will process remaining N0 subsequences
// of T0 - T1 length
const int leftmost_batch = N0 + N1;
const int rightmost_batch = N0;
const int leftmost_seq_length = T1;
const int rightmost_seq_length = T0 - T1;
// Number of channels
const int common_feature_size = 1024;
// RNN primitive characteristics
const int common_n_layers = 1;
const int lstm_n_gates = 4;
void simple_net(engine::kind engine_kind) {
    using tag = memory::format_tag;
    using dt = memory::data_type;
    auto eng = engine(engine_kind, 0);
    stream s(eng);
    bool is_training = true;
    auto fwd_inf_train = is_training ? prop_kind::forward_training
                                     : prop_kind::forward_inference;
    std::vector<primitive> fwd_net;
    std::vector<primitive> bwd_net;
    // Input tensor holds two batches with different sequence lengths.
    // Shorter sequences are padded
    memory::dims net_src_dims = {
            T0, // time, maximum sequence length
            N0 + N1, // n, total batch size
            common_feature_size // c, common number of channels
    };
    // Two RNN primitives for different sequence lengths,
    // one unidirectional layer, LSTM-based
    memory::dims leftmost_src_layer_dims = {
            leftmost_seq_length, // time
            leftmost_batch, // n
            common_feature_size // c
    };
    memory::dims rightmost_src_layer_dims = {
            rightmost_seq_length, // time
            rightmost_batch, // n
            common_feature_size // c
    };
    memory::dims common_weights_layer_dims = {
            common_n_layers, // layers
            1, // directions
            common_feature_size, // input feature size
            lstm_n_gates, // gates number
            common_feature_size // output feature size
    };
    memory::dims common_weights_iter_dims = {
            common_n_layers, // layers
            1, // directions
            common_feature_size, // input feature size
            lstm_n_gates, // gates number
            common_feature_size // output feature size
    };
    memory::dims common_bias_dims = {
            common_n_layers, // layers
            1, // directions
            lstm_n_gates, // gates number
            common_feature_size // output feature size
    };
    memory::dims leftmost_dst_layer_dims = {
            leftmost_seq_length, // time
            leftmost_batch, // n
            common_feature_size // c
    };
    memory::dims rightmost_dst_layer_dims = {
            rightmost_seq_length, // time
            rightmost_batch, // n
            common_feature_size // c
    };
    // leftmost primitive passes its states to the next RNN iteration
    // so it needs dst_iter parameter.
    //
    // rightmost primitive will consume these as src_iter and will access the
    // memory via a sub-memory because it will have different batch dimension.
    // We have arranged our primitives so that
    // leftmost_batch >= rightmost_batch, and so the rightmost data will fit
    // into the memory allocated for the leftmost.
    memory::dims leftmost_dst_iter_dims = {
            common_n_layers, // layers
            1, // directions
            leftmost_batch, // n
            common_feature_size // c
    };
    memory::dims leftmost_dst_iter_c_dims = {
            common_n_layers, // layers
            1, // directions
            leftmost_batch, // n
            common_feature_size // c
    };
    memory::dims rightmost_src_iter_dims = {
            common_n_layers, // layers
            1, // directions
            rightmost_batch, // n
            common_feature_size // c
    };
    memory::dims rightmost_src_iter_c_dims = {
            common_n_layers, // layers
            1, // directions
            rightmost_batch, // n
            common_feature_size // c
    };
    // multiplication of tensor dimensions
    auto tz_volume = [=](memory::dims tz_dims) {
        return std::accumulate(tz_dims.begin(), tz_dims.end(), (memory::dim)1,
                std::multiplies<memory::dim>());
    };
    // Create auxillary f32 memory descriptor
    // based on user- supplied dimensions and layout.
    auto formatted_md
            = [=](const memory::dims &dimensions, memory::format_tag layout) {
                  return memory::desc {{dimensions}, dt::f32, layout};
              };
    // Create auxillary generic f32 memory descriptor
    // based on supplied dimensions, with format_tag::any.
    auto generic_md = [=](const memory::dims &dimensions) {
        return formatted_md(dimensions, tag::any);
    };
    //
    // I/O memory, coming from user
    //
    // Net input
    std::vector<float> net_src(tz_volume(net_src_dims), 1.0f);
    // NOTE: in this example we study input sequences with variable batch
    // dimension, which get processed by two separate RNN primitives, thus
    // the destination memory for the two will have different shapes: batch
    // is the second dimension currently: see format_tag::tnc.
    // We are not copying the output to some common user provided memory as we
    // suggest that the user should rather keep the two output memories separate
    // throughout the whole topology and only reorder to something else as
    // needed.
    // So there's no common net_dst, but there are two destinations instead:
    //    leftmost_dst_layer_memory
    //    rightmost_dst_layer_memory
    // Memory for the user allocated memory
    // Suppose user data is in tnc format.
    auto net_src_memory
            = dnnl::memory({{net_src_dims}, dt::f32, tag::tnc}, eng);
    write_to_dnnl_memory(net_src.data(), net_src_memory);
    // src_layer memory of the leftmost and rightmost RNN primitives
    // are accessed through the respective sub-memories in larger memory.
    // View primitives compute the strides to accommodate for padding.
    auto user_leftmost_src_layer_md = net_src_memory.get_desc().submemory_desc(
            leftmost_src_layer_dims, {0, 0, 0}); // t, n, c offsets
    auto user_rightmost_src_layer_md
            = net_src_memory.get_desc().submemory_desc(rightmost_src_layer_dims,
                    {leftmost_seq_length, 0, 0}); // t, n, c offsets
    auto leftmost_src_layer_memory = net_src_memory;
    auto rightmost_src_layer_memory = net_src_memory;
    // Other user provided memory arrays, descriptors and primitives with the
    // data layouts chosen by user. We'll have to reorder if RNN
    // primitive prefers it in a different format.
    std::vector<float> user_common_weights_layer(
            tz_volume(common_weights_layer_dims), 1.0f);
    auto user_common_weights_layer_memory = dnnl::memory(
            {common_weights_layer_dims, dt::f32, tag::ldigo}, eng);
    write_to_dnnl_memory(
            user_common_weights_layer.data(), user_common_weights_layer_memory);
    std::vector<float> user_common_weights_iter(
            tz_volume(common_weights_iter_dims), 1.0f);
    auto user_common_weights_iter_memory = dnnl::memory(
            {{common_weights_iter_dims}, dt::f32, tag::ldigo}, eng);
    write_to_dnnl_memory(
            user_common_weights_layer.data(), user_common_weights_iter_memory);
    std::vector<float> user_common_bias(tz_volume(common_bias_dims), 1.0f);
    auto user_common_bias_memory
            = dnnl::memory({{common_bias_dims}, dt::f32, tag::ldgo}, eng);
    write_to_dnnl_memory(user_common_bias.data(), user_common_bias_memory);
    std::vector<float> user_leftmost_dst_layer(
            tz_volume(leftmost_dst_layer_dims), 1.0f);
    auto user_leftmost_dst_layer_memory
            = dnnl::memory({{leftmost_dst_layer_dims}, dt::f32, tag::tnc}, eng);
    write_to_dnnl_memory(
            user_leftmost_dst_layer.data(), user_leftmost_dst_layer_memory);
    std::vector<float> user_rightmost_dst_layer(
            tz_volume(rightmost_dst_layer_dims), 1.0f);
    auto user_rightmost_dst_layer_memory = dnnl::memory(
            {{rightmost_dst_layer_dims}, dt::f32, tag::tnc}, eng);
    write_to_dnnl_memory(
            user_rightmost_dst_layer.data(), user_rightmost_dst_layer_memory);
    // Describe layer, forward pass, leftmost primitive.
    // There are no primitives to the left from here,
    // so src_iter_desc needs to be zero memory desc
    auto leftmost_prim_desc = lstm_forward::primitive_desc(eng, // engine
            fwd_inf_train, // aprop_kind
            rnn_direction::unidirectional_left2right, // direction
            user_leftmost_src_layer_md, // src_layer_desc
            memory::desc(), // src_iter_desc
            memory::desc(), // src_iter_c_desc
            generic_md(common_weights_layer_dims), // weights_layer_desc
            generic_md(common_weights_iter_dims), // weights_iter_desc
            generic_md(common_bias_dims), // bias_desc
            formatted_md(leftmost_dst_layer_dims, tag::tnc), // dst_layer_desc
            generic_md(leftmost_dst_iter_dims), // dst_iter_desc
            generic_md(leftmost_dst_iter_c_dims) // dst_iter_c_desc
    );
    //
    // Need to connect leftmost and rightmost via "iter" parameters.
    // We allocate memory here based on the shapes provided by RNN primitive.
    //
    auto leftmost_dst_iter_memory
            = dnnl::memory(leftmost_prim_desc.dst_iter_desc(), eng);
    auto leftmost_dst_iter_c_memory
            = dnnl::memory(leftmost_prim_desc.dst_iter_c_desc(), eng);
    // rightmost src_iter will be a sub-memory of dst_iter of leftmost
    auto rightmost_src_iter_md
            = leftmost_dst_iter_memory.get_desc().submemory_desc(
                    rightmost_src_iter_dims,
                    {0, 0, 0, 0}); // l, d, n, c offsets
    auto rightmost_src_iter_memory = leftmost_dst_iter_memory;
    auto rightmost_src_iter_c_md
            = leftmost_dst_iter_c_memory.get_desc().submemory_desc(
                    rightmost_src_iter_c_dims,
                    {0, 0, 0, 0}); // l, d, n, c offsets
    auto rightmost_src_iter_c_memory = leftmost_dst_iter_c_memory;
    // Now rightmost primitive
    // There are no primitives to the right from here,
    // so dst_iter_desc is explicit zero memory desc
    auto rightmost_prim_desc = lstm_forward::primitive_desc(eng, // engine
            fwd_inf_train, // aprop_kind
            rnn_direction::unidirectional_left2right, // direction
            user_rightmost_src_layer_md, // src_layer_desc
            rightmost_src_iter_md, // src_iter_desc
            rightmost_src_iter_c_md, // src_iter_c_desc
            generic_md(common_weights_layer_dims), // weights_layer_desc
            generic_md(common_weights_iter_dims), // weights_iter_desc
            generic_md(common_bias_dims), // bias_desc
            formatted_md(rightmost_dst_layer_dims, tag::tnc), // dst_layer_desc
            memory::desc(), // dst_iter_desc
            memory::desc() // dst_iter_c_desc
    );
    //
    // Weights and biases, layer memory
    // Same layout should work across the layer, no reorders
    // needed between leftmost and rigthmost, only reordering
    // user memory to the RNN-friendly shapes.
    //
    auto common_weights_layer_memory = user_common_weights_layer_memory;
    if (leftmost_prim_desc.weights_layer_desc()
            != common_weights_layer_memory.get_desc()) {
        common_weights_layer_memory
                = dnnl::memory(leftmost_prim_desc.weights_layer_desc(), eng);
        reorder(user_common_weights_layer_memory, common_weights_layer_memory)
                .execute(s, user_common_weights_layer_memory,
                        common_weights_layer_memory);
    }
    auto common_weights_iter_memory = user_common_weights_iter_memory;
    if (leftmost_prim_desc.weights_iter_desc()
            != common_weights_iter_memory.get_desc()) {
        common_weights_iter_memory
                = dnnl::memory(leftmost_prim_desc.weights_iter_desc(), eng);
        reorder(user_common_weights_iter_memory, common_weights_iter_memory)
                .execute(s, user_common_weights_iter_memory,
                        common_weights_iter_memory);
    }
    auto common_bias_memory = user_common_bias_memory;
    if (leftmost_prim_desc.bias_desc() != common_bias_memory.get_desc()) {
        common_bias_memory = dnnl::memory(leftmost_prim_desc.bias_desc(), eng);
        reorder(user_common_bias_memory, common_bias_memory)
                .execute(s, user_common_bias_memory, common_bias_memory);
    }
    //
    // Destination layer memory
    //
    auto leftmost_dst_layer_memory = user_leftmost_dst_layer_memory;
    if (leftmost_prim_desc.dst_layer_desc()
            != leftmost_dst_layer_memory.get_desc()) {
        leftmost_dst_layer_memory
                = dnnl::memory(leftmost_prim_desc.dst_layer_desc(), eng);
        reorder(user_leftmost_dst_layer_memory, leftmost_dst_layer_memory)
                .execute(s, user_leftmost_dst_layer_memory,
                        leftmost_dst_layer_memory);
    }
    auto rightmost_dst_layer_memory = user_rightmost_dst_layer_memory;
    if (rightmost_prim_desc.dst_layer_desc()
            != rightmost_dst_layer_memory.get_desc()) {
        rightmost_dst_layer_memory
                = dnnl::memory(rightmost_prim_desc.dst_layer_desc(), eng);
        reorder(user_rightmost_dst_layer_memory, rightmost_dst_layer_memory)
                .execute(s, user_rightmost_dst_layer_memory,
                        rightmost_dst_layer_memory);
    }
    // We also create workspace memory based on the information from
    // the workspace_primitive_desc(). This is needed for internal
    // communication between forward and backward primitives during
    // training.
    auto create_ws = [=](dnnl::lstm_forward::primitive_desc &pd) {
        return dnnl::memory(pd.workspace_desc(), eng);
    };
    auto leftmost_workspace_memory = create_ws(leftmost_prim_desc);
    auto rightmost_workspace_memory = create_ws(rightmost_prim_desc);
    // Construct the RNN primitive objects
    lstm_forward leftmost_layer(leftmost_prim_desc);
    leftmost_layer.execute(s,
            {{DNNL_ARG_SRC_LAYER, leftmost_src_layer_memory},
                    {DNNL_ARG_WEIGHTS_LAYER, common_weights_layer_memory},
                    {DNNL_ARG_WEIGHTS_ITER, common_weights_iter_memory},
                    {DNNL_ARG_BIAS, common_bias_memory},
                    {DNNL_ARG_DST_LAYER, leftmost_dst_layer_memory},
                    {DNNL_ARG_DST_ITER, leftmost_dst_iter_memory},
                    {DNNL_ARG_DST_ITER_C, leftmost_dst_iter_c_memory},
                    {DNNL_ARG_WORKSPACE, leftmost_workspace_memory}});
    lstm_forward rightmost_layer(rightmost_prim_desc);
    rightmost_layer.execute(s,
            {{DNNL_ARG_SRC_LAYER, rightmost_src_layer_memory},
                    {DNNL_ARG_SRC_ITER, rightmost_src_iter_memory},
                    {DNNL_ARG_SRC_ITER_C, rightmost_src_iter_c_memory},
                    {DNNL_ARG_WEIGHTS_LAYER, common_weights_layer_memory},
                    {DNNL_ARG_WEIGHTS_ITER, common_weights_iter_memory},
                    {DNNL_ARG_BIAS, common_bias_memory},
                    {DNNL_ARG_DST_LAYER, rightmost_dst_layer_memory},
                    {DNNL_ARG_WORKSPACE, rightmost_workspace_memory}});
    // No backward pass for inference
    if (!is_training) return;
    //
    // Backward primitives will reuse memory from forward
    // and allocate/describe specifics here. Only relevant for training.
    //
    // User-provided memory for backward by data output
    std::vector<float> net_diff_src(tz_volume(net_src_dims), 1.0f);
    auto net_diff_src_memory
            = dnnl::memory(formatted_md(net_src_dims, tag::tnc), eng);
    write_to_dnnl_memory(net_diff_src.data(), net_diff_src_memory);
    // diff_src follows the same layout we have for net_src
    auto user_leftmost_diff_src_layer_md
            = net_diff_src_memory.get_desc().submemory_desc(
                    leftmost_src_layer_dims, {0, 0, 0}); // t, n, c offsets
    auto user_rightmost_diff_src_layer_md
            = net_diff_src_memory.get_desc().submemory_desc(
                    rightmost_src_layer_dims,
                    {leftmost_seq_length, 0, 0}); // t, n, c offsets
    auto leftmost_diff_src_layer_memory = net_diff_src_memory;
    auto rightmost_diff_src_layer_memory = net_diff_src_memory;
    // User-provided memory for backpropagation by weights
    std::vector<float> user_common_diff_weights_layer(
            tz_volume(common_weights_layer_dims), 1.0f);
    auto user_common_diff_weights_layer_memory = dnnl::memory(
            formatted_md(common_weights_layer_dims, tag::ldigo), eng);
    write_to_dnnl_memory(user_common_diff_weights_layer.data(),
            user_common_diff_weights_layer_memory);
    std::vector<float> user_common_diff_bias(tz_volume(common_bias_dims), 1.0f);
    auto user_common_diff_bias_memory
            = dnnl::memory(formatted_md(common_bias_dims, tag::ldgo), eng);
    write_to_dnnl_memory(
            user_common_diff_bias.data(), user_common_diff_bias_memory);
    // User-provided input to the backward primitive.
    // To be updated by the user after forward pass using some cost function.
    memory::dims net_diff_dst_dims = {
            T0, // time
            N0 + N1, // n
            common_feature_size // c
    };
    // Suppose user data is in tnc format.
    std::vector<float> net_diff_dst(tz_volume(net_diff_dst_dims), 1.0f);
    auto net_diff_dst_memory
            = dnnl::memory(formatted_md(net_diff_dst_dims, tag::tnc), eng);
    write_to_dnnl_memory(net_diff_dst.data(), net_diff_dst_memory);
    // diff_dst_layer memory of the leftmost and rightmost RNN primitives
    // are accessed through the respective sub-memory in larger memory.
    // View primitives compute the strides to accommodate for padding.
    auto user_leftmost_diff_dst_layer_md
            = net_diff_dst_memory.get_desc().submemory_desc(
                    leftmost_dst_layer_dims, {0, 0, 0}); // t, n, c offsets
    auto user_rightmost_diff_dst_layer_md
            = net_diff_dst_memory.get_desc().submemory_desc(
                    rightmost_dst_layer_dims,
                    {leftmost_seq_length, 0, 0}); // t, n, c offsets
    auto leftmost_diff_dst_layer_memory = net_diff_dst_memory;
    auto rightmost_diff_dst_layer_memory = net_diff_dst_memory;
    // Backward leftmost primitive descriptor
    auto leftmost_bwd_prim_desc = lstm_backward::primitive_desc(eng, // engine
            prop_kind::backward, // aprop_kind
            rnn_direction::unidirectional_left2right, // direction
            user_leftmost_src_layer_md, // src_layer_desc
            memory::desc(), // src_iter_desc
            memory::desc(), // src_iter_c_desc
            generic_md(common_weights_layer_dims), // weights_layer_desc
            generic_md(common_weights_iter_dims), // weights_iter_desc
            generic_md(common_bias_dims), // bias_desc
            formatted_md(leftmost_dst_layer_dims, tag::tnc), // dst_layer_desc
            generic_md(leftmost_dst_iter_dims), // dst_iter_desc
            generic_md(leftmost_dst_iter_c_dims), // dst_iter_c_desc
            user_leftmost_diff_src_layer_md, // diff_src_layer_desc
            memory::desc(), // diff_src_iter_desc
            memory::desc(), // diff_src_iter_c_desc
            generic_md(common_weights_layer_dims), // diff_weights_layer_desc
            generic_md(common_weights_iter_dims), // diff_weights_iter_desc
            generic_md(common_bias_dims), // diff_bias_desc
            user_leftmost_diff_dst_layer_md, // diff_dst_layer_desc
            generic_md(leftmost_dst_iter_dims), // diff_dst_iter_desc
            generic_md(leftmost_dst_iter_c_dims), // diff_dst_iter_c_desc
            leftmost_prim_desc // hint from forward pass
    );
    // As the batch dimensions are different between leftmost and rightmost
    // we need to use a sub-memory. rightmost needs less memory, so it will
    // be a sub-memory of leftmost.
    auto leftmost_diff_dst_iter_memory
            = dnnl::memory(leftmost_bwd_prim_desc.diff_dst_iter_desc(), eng);
    auto leftmost_diff_dst_iter_c_memory
            = dnnl::memory(leftmost_bwd_prim_desc.diff_dst_iter_c_desc(), eng);
    auto rightmost_diff_src_iter_md
            = leftmost_diff_dst_iter_memory.get_desc().submemory_desc(
                    rightmost_src_iter_dims,
                    {0, 0, 0, 0}); // l, d, n, c offsets
    auto rightmost_diff_src_iter_memory = leftmost_diff_dst_iter_memory;
    auto rightmost_diff_src_iter_c_md
            = leftmost_diff_dst_iter_c_memory.get_desc().submemory_desc(
                    rightmost_src_iter_c_dims,
                    {0, 0, 0, 0}); // l, d, n, c offsets
    auto rightmost_diff_src_iter_c_memory = leftmost_diff_dst_iter_c_memory;
    // Backward rightmost primitive descriptor
    auto rightmost_bwd_prim_desc = lstm_backward::primitive_desc(eng, // engine
            prop_kind::backward, // aprop_kind
            rnn_direction::unidirectional_left2right, // direction
            user_rightmost_src_layer_md, // src_layer_desc
            generic_md(rightmost_src_iter_dims), // src_iter_desc
            generic_md(rightmost_src_iter_c_dims), // src_iter_c_desc
            generic_md(common_weights_layer_dims), // weights_layer_desc
            generic_md(common_weights_iter_dims), // weights_iter_desc
            generic_md(common_bias_dims), // bias_desc
            formatted_md(rightmost_dst_layer_dims, tag::tnc), // dst_layer_desc
            memory::desc(), // dst_iter_desc
            memory::desc(), // dst_iter_c_desc
            user_rightmost_diff_src_layer_md, // diff_src_layer_desc
            rightmost_diff_src_iter_md, // diff_src_iter_desc
            rightmost_diff_src_iter_c_md, // diff_src_iter_c_desc
            generic_md(common_weights_layer_dims), // diff_weights_layer_desc
            generic_md(common_weights_iter_dims), // diff_weights_iter_desc
            generic_md(common_bias_dims), // diff_bias_desc
            user_rightmost_diff_dst_layer_md, // diff_dst_layer_desc
            memory::desc(), // diff_dst_iter_desc
            memory::desc(), // diff_dst_iter_c_desc
            rightmost_prim_desc // hint from forward pass
    );
    //
    // Memory for backward pass
    //
    // src layer uses the same memory as forward
    auto leftmost_src_layer_bwd_memory = leftmost_src_layer_memory;
    auto rightmost_src_layer_bwd_memory = rightmost_src_layer_memory;
    // Memory for weights and biases for backward pass
    // Try to use the same memory between forward and backward, but
    // sometimes reorders are needed.
    auto common_weights_layer_bwd_memory = common_weights_layer_memory;
    if (leftmost_bwd_prim_desc.weights_layer_desc()
            != leftmost_prim_desc.weights_layer_desc()) {
        common_weights_layer_bwd_memory
                = memory(leftmost_bwd_prim_desc.weights_layer_desc(), eng);
        reorder(common_weights_layer_memory, common_weights_layer_bwd_memory)
                .execute(s, common_weights_layer_memory,
                        common_weights_layer_bwd_memory);
    }
    auto common_weights_iter_bwd_memory = common_weights_iter_memory;
    if (leftmost_bwd_prim_desc.weights_iter_desc()
            != leftmost_prim_desc.weights_iter_desc()) {
        common_weights_iter_bwd_memory
                = memory(leftmost_bwd_prim_desc.weights_iter_desc(), eng);
        reorder(common_weights_iter_memory, common_weights_iter_bwd_memory)
                .execute(s, common_weights_iter_memory,
                        common_weights_iter_bwd_memory);
    }
    auto common_bias_bwd_memory = common_bias_memory;
    if (leftmost_bwd_prim_desc.bias_desc() != common_bias_memory.get_desc()) {
        common_bias_bwd_memory
                = dnnl::memory(leftmost_bwd_prim_desc.bias_desc(), eng);
        reorder(common_bias_memory, common_bias_bwd_memory)
                .execute(s, common_bias_memory, common_bias_bwd_memory);
    }
    // diff_weights and biases
    auto common_diff_weights_layer_memory
            = user_common_diff_weights_layer_memory;
    auto reorder_common_diff_weights_layer = false;
    if (leftmost_bwd_prim_desc.diff_weights_layer_desc()
            != common_diff_weights_layer_memory.get_desc()) {
        common_diff_weights_layer_memory = dnnl::memory(
                leftmost_bwd_prim_desc.diff_weights_layer_desc(), eng);
        reorder_common_diff_weights_layer = true;
    }
    auto common_diff_bias_memory = user_common_diff_bias_memory;
    auto reorder_common_diff_bias = false;
    if (leftmost_bwd_prim_desc.diff_bias_desc()
            != common_diff_bias_memory.get_desc()) {
        common_diff_bias_memory
                = dnnl::memory(leftmost_bwd_prim_desc.diff_bias_desc(), eng);
        reorder_common_diff_bias = true;
    }
    // dst_layer memory for backward pass
    auto leftmost_dst_layer_bwd_memory = leftmost_dst_layer_memory;
    if (leftmost_bwd_prim_desc.dst_layer_desc()
            != leftmost_dst_layer_bwd_memory.get_desc()) {
        leftmost_dst_layer_bwd_memory
                = dnnl::memory(leftmost_bwd_prim_desc.dst_layer_desc(), eng);
        reorder(leftmost_dst_layer_memory, leftmost_dst_layer_bwd_memory)
                .execute(s, leftmost_dst_layer_memory,
                        leftmost_dst_layer_bwd_memory);
    }
    auto rightmost_dst_layer_bwd_memory = rightmost_dst_layer_memory;
    if (rightmost_bwd_prim_desc.dst_layer_desc()
            != rightmost_dst_layer_bwd_memory.get_desc()) {
        rightmost_dst_layer_bwd_memory
                = dnnl::memory(rightmost_bwd_prim_desc.dst_layer_desc(), eng);
        reorder(rightmost_dst_layer_memory, rightmost_dst_layer_bwd_memory)
                .execute(s, rightmost_dst_layer_memory,
                        rightmost_dst_layer_bwd_memory);
    }
    // Similar to forward, the backward primitives are connected
    // via "iter" parameters.
    auto common_diff_weights_iter_memory = dnnl::memory(
            leftmost_bwd_prim_desc.diff_weights_iter_desc(), eng);
    auto leftmost_dst_iter_bwd_memory = leftmost_dst_iter_memory;
    if (leftmost_bwd_prim_desc.dst_iter_desc()
            != leftmost_dst_iter_bwd_memory.get_desc()) {
        leftmost_dst_iter_bwd_memory
                = dnnl::memory(leftmost_bwd_prim_desc.dst_iter_desc(), eng);
        reorder(leftmost_dst_iter_memory, leftmost_dst_iter_bwd_memory)
                .execute(s, leftmost_dst_iter_memory,
                        leftmost_dst_iter_bwd_memory);
    }
    auto leftmost_dst_iter_c_bwd_memory = leftmost_dst_iter_c_memory;
    if (leftmost_bwd_prim_desc.dst_iter_c_desc()
            != leftmost_dst_iter_c_bwd_memory.get_desc()) {
        leftmost_dst_iter_c_bwd_memory
                = dnnl::memory(leftmost_bwd_prim_desc.dst_iter_c_desc(), eng);
        reorder(leftmost_dst_iter_c_memory, leftmost_dst_iter_c_bwd_memory)
                .execute(s, leftmost_dst_iter_c_memory,
                        leftmost_dst_iter_c_bwd_memory);
    }
    // Construct the RNN primitive objects for backward
    lstm_backward rightmost_layer_bwd(rightmost_bwd_prim_desc);
    rightmost_layer_bwd.execute(s,
            {{DNNL_ARG_SRC_LAYER, rightmost_src_layer_bwd_memory},
                    {DNNL_ARG_SRC_ITER, rightmost_src_iter_memory},
                    {DNNL_ARG_SRC_ITER_C, rightmost_src_iter_c_memory},
                    {DNNL_ARG_WEIGHTS_LAYER, common_weights_layer_bwd_memory},
                    {DNNL_ARG_WEIGHTS_ITER, common_weights_iter_bwd_memory},
                    {DNNL_ARG_BIAS, common_bias_bwd_memory},
                    {DNNL_ARG_DST_LAYER, rightmost_dst_layer_bwd_memory},
                    {DNNL_ARG_DIFF_SRC_LAYER, rightmost_diff_src_layer_memory},
                    {DNNL_ARG_DIFF_SRC_ITER, rightmost_diff_src_iter_memory},
                    {DNNL_ARG_DIFF_SRC_ITER_C,
                            rightmost_diff_src_iter_c_memory},
                    {DNNL_ARG_DIFF_WEIGHTS_LAYER,
                            common_diff_weights_layer_memory},
                    {DNNL_ARG_DIFF_WEIGHTS_ITER,
                            common_diff_weights_iter_memory},
                    {DNNL_ARG_DIFF_BIAS, common_diff_bias_memory},
                    {DNNL_ARG_DIFF_DST_LAYER, rightmost_diff_dst_layer_memory},
                    {DNNL_ARG_WORKSPACE, rightmost_workspace_memory}});
    lstm_backward leftmost_layer_bwd(leftmost_bwd_prim_desc);
    leftmost_layer_bwd.execute(s,
            {{DNNL_ARG_SRC_LAYER, leftmost_src_layer_bwd_memory},
                    {DNNL_ARG_WEIGHTS_LAYER, common_weights_layer_bwd_memory},
                    {DNNL_ARG_WEIGHTS_ITER, common_weights_iter_bwd_memory},
                    {DNNL_ARG_BIAS, common_bias_bwd_memory},
                    {DNNL_ARG_DST_LAYER, leftmost_dst_layer_bwd_memory},
                    {DNNL_ARG_DST_ITER, leftmost_dst_iter_bwd_memory},
                    {DNNL_ARG_DST_ITER_C, leftmost_dst_iter_c_bwd_memory},
                    {DNNL_ARG_DIFF_SRC_LAYER, leftmost_diff_src_layer_memory},
                    {DNNL_ARG_DIFF_WEIGHTS_LAYER,
                            common_diff_weights_layer_memory},
                    {DNNL_ARG_DIFF_WEIGHTS_ITER,
                            common_diff_weights_iter_memory},
                    {DNNL_ARG_DIFF_BIAS, common_diff_bias_memory},
                    {DNNL_ARG_DIFF_DST_LAYER, leftmost_diff_dst_layer_memory},
                    {DNNL_ARG_DIFF_DST_ITER, leftmost_diff_dst_iter_memory},
                    {DNNL_ARG_DIFF_DST_ITER_C, leftmost_diff_dst_iter_c_memory},
                    {DNNL_ARG_WORKSPACE, leftmost_workspace_memory}});
    if (reorder_common_diff_weights_layer) {
        reorder(common_diff_weights_layer_memory,
                user_common_diff_weights_layer_memory)
                .execute(s, common_diff_weights_layer_memory,
                        user_common_diff_weights_layer_memory);
    }
    if (reorder_common_diff_bias) {
        reorder(common_diff_bias_memory, user_common_diff_bias_memory)
                .execute(s, common_diff_bias_memory,
                        user_common_diff_bias_memory);
    }
    //
    // User updates weights and bias using diffs
    //
    s.wait();
}
int main(int argc, char **argv) {
    return handle_example_errors(simple_net, parse_engine_kind(argc, argv));
}