.. index:: pair: struct; dnnl::lstm_forward::desc
.. _doxid-structdnnl_1_1lstm__forward_1_1desc:

struct dnnl::lstm_forward::desc
===============================

.. toctree::
	:hidden:

Overview
~~~~~~~~

Descriptor for an LSTM forward propagation primitive. :ref:`More...<details-structdnnl_1_1lstm__forward_1_1desc>`


.. ref-code-block:: cpp
	:class: doxyrest-overview-code-block

	#include <dnnl.hpp>
	
	struct desc
	{
		// fields
	
		:ref:`dnnl_rnn_desc_t<doxid-structdnnl__rnn__desc__t>` :target:`data<doxid-structdnnl_1_1lstm__forward_1_1desc_1a9156fe0f8ff193c6ce76d30299d8c59a>`;

		// construction
	
		:ref:`desc<doxid-structdnnl_1_1lstm__forward_1_1desc_1a34bca69c5da0771ca90bdd2c037ceb6b>`(
			:ref:`prop_kind<doxid-group__dnnl__api__attributes_1gac7db48f6583aa9903e54c2a39d65438f>` aprop_kind,
			:ref:`rnn_direction<doxid-group__dnnl__api__rnn_1ga33315cf335d1cbe26fd6b70d956e23d5>` direction,
			const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& src_layer_desc,
			const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& src_iter_desc,
			const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& src_iter_c_desc,
			const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& weights_layer_desc,
			const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& weights_iter_desc,
			const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& weights_peephole_desc,
			const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& weights_projection_desc,
			const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& bias_desc,
			const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& dst_layer_desc,
			const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& dst_iter_desc,
			const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& dst_iter_c_desc,
			:ref:`rnn_flags<doxid-group__dnnl__api__rnn_1gad27d0db2a86ae3072207769f5c2ddd1e>` flags = :ref:`rnn_flags::undef<doxid-group__dnnl__api__rnn_1ggad27d0db2a86ae3072207769f5c2ddd1eaf31ee5e3824f1f5e5d206bdf3029f22b>`
			);
	
		:ref:`desc<doxid-structdnnl_1_1lstm__forward_1_1desc_1a9a621c76d5797ab63e597cf412075cff>`(
			:ref:`prop_kind<doxid-group__dnnl__api__attributes_1gac7db48f6583aa9903e54c2a39d65438f>` aprop_kind,
			:ref:`rnn_direction<doxid-group__dnnl__api__rnn_1ga33315cf335d1cbe26fd6b70d956e23d5>` direction,
			const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& src_layer_desc,
			const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& src_iter_desc,
			const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& src_iter_c_desc,
			const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& weights_layer_desc,
			const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& weights_iter_desc,
			const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& weights_peephole_desc,
			const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& bias_desc,
			const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& dst_layer_desc,
			const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& dst_iter_desc,
			const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& dst_iter_c_desc,
			:ref:`rnn_flags<doxid-group__dnnl__api__rnn_1gad27d0db2a86ae3072207769f5c2ddd1e>` flags = :ref:`rnn_flags::undef<doxid-group__dnnl__api__rnn_1ggad27d0db2a86ae3072207769f5c2ddd1eaf31ee5e3824f1f5e5d206bdf3029f22b>`
			);
	
		:ref:`desc<doxid-structdnnl_1_1lstm__forward_1_1desc_1a2d895c8ee23f15cbfb2cd6b67551673f>`(
			:ref:`prop_kind<doxid-group__dnnl__api__attributes_1gac7db48f6583aa9903e54c2a39d65438f>` aprop_kind,
			:ref:`rnn_direction<doxid-group__dnnl__api__rnn_1ga33315cf335d1cbe26fd6b70d956e23d5>` direction,
			const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& src_layer_desc,
			const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& src_iter_desc,
			const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& src_iter_c_desc,
			const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& weights_layer_desc,
			const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& weights_iter_desc,
			const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& bias_desc,
			const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& dst_layer_desc,
			const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& dst_iter_desc,
			const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& dst_iter_c_desc,
			:ref:`rnn_flags<doxid-group__dnnl__api__rnn_1gad27d0db2a86ae3072207769f5c2ddd1e>` flags = :ref:`rnn_flags::undef<doxid-group__dnnl__api__rnn_1ggad27d0db2a86ae3072207769f5c2ddd1eaf31ee5e3824f1f5e5d206bdf3029f22b>`
			);
	};
.. _details-structdnnl_1_1lstm__forward_1_1desc:

Detailed Documentation
~~~~~~~~~~~~~~~~~~~~~~

Descriptor for an LSTM forward propagation primitive.

Construction
------------

.. index:: pair: function; desc
.. _doxid-structdnnl_1_1lstm__forward_1_1desc_1a34bca69c5da0771ca90bdd2c037ceb6b:

.. ref-code-block:: cpp
	:class: doxyrest-title-code-block

	desc(
		:ref:`prop_kind<doxid-group__dnnl__api__attributes_1gac7db48f6583aa9903e54c2a39d65438f>` aprop_kind,
		:ref:`rnn_direction<doxid-group__dnnl__api__rnn_1ga33315cf335d1cbe26fd6b70d956e23d5>` direction,
		const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& src_layer_desc,
		const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& src_iter_desc,
		const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& src_iter_c_desc,
		const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& weights_layer_desc,
		const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& weights_iter_desc,
		const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& weights_peephole_desc,
		const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& weights_projection_desc,
		const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& bias_desc,
		const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& dst_layer_desc,
		const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& dst_iter_desc,
		const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& dst_iter_c_desc,
		:ref:`rnn_flags<doxid-group__dnnl__api__rnn_1gad27d0db2a86ae3072207769f5c2ddd1e>` flags = :ref:`rnn_flags::undef<doxid-group__dnnl__api__rnn_1ggad27d0db2a86ae3072207769f5c2ddd1eaf31ee5e3824f1f5e5d206bdf3029f22b>`
		)

Constructs a descriptor for an LSTM (with or without peephole and with or without projection) forward propagation primitive.

The following arguments may point to a zero memory descriptor:

* ``src_iter_desc`` together with ``src_iter_c_desc``,

* ``weights_peephole_desc``,

* ``bias_desc``,

* ``dst_iter_desc`` together with ``dst_iter_c_desc``.

This would then indicate that the LSTM forward propagation primitive should not use them and should default to zero values instead.

The ``weights_projection_desc`` may point to a zero memory descriptor. This would then indicate that the LSTM doesn't have recurrent projection layer.

.. note:: 

   All memory descriptors can be initialized with an :ref:`dnnl::memory::format_tag::any <doxid-structdnnl_1_1memory_1a8e71077ed6a5f7fb7b3e6e1a5a2ecf3fa100b8cad7cf2a56f6df78f171f97a1ec>` value of ``format_tag``.



.. rubric:: Parameters:

.. list-table::
	:widths: 20 80

	*
		- aprop_kind

		- Propagation kind. Possible values are :ref:`dnnl::prop_kind::forward_training <doxid-group__dnnl__api__attributes_1ggac7db48f6583aa9903e54c2a39d65438fa24775787fab8f13aa4809e1ce8f82aeb>`, and :ref:`dnnl::prop_kind::forward_inference <doxid-group__dnnl__api__attributes_1ggac7db48f6583aa9903e54c2a39d65438fa3b9fad4f80d45368f856b5403198ac4c>`.

	*
		- direction

		- RNN direction. See :ref:`dnnl::rnn_direction <doxid-group__dnnl__api__rnn_1ga33315cf335d1cbe26fd6b70d956e23d5>` for more info.

	*
		- src_layer_desc

		- Memory descriptor for the input vector.

	*
		- src_iter_desc

		- Memory descriptor for the input recurrent hidden state vector.

	*
		- src_iter_c_desc

		- Memory descriptor for the input recurrent cell state vector.

	*
		- weights_layer_desc

		- Memory descriptor for the weights applied to the layer input.

	*
		- weights_iter_desc

		- Memory descriptor for the weights applied to the recurrent input.

	*
		- weights_peephole_desc

		- Memory descriptor for the weights applied to the cell states (according to the Peephole LSTM formula).

	*
		- weights_projection_desc

		- Memory descriptor for the weights applied to the hidden states to get the recurrent projection (according to the Projection LSTM formula).

	*
		- bias_desc

		- Bias memory descriptor.

	*
		- dst_layer_desc

		- Memory descriptor for the output vector.

	*
		- dst_iter_desc

		- Memory descriptor for the output recurrent hidden state vector.

	*
		- dst_iter_c_desc

		- Memory descriptor for the output recurrent cell state vector.

	*
		- flags

		- Unused.

.. index:: pair: function; desc
.. _doxid-structdnnl_1_1lstm__forward_1_1desc_1a9a621c76d5797ab63e597cf412075cff:

.. ref-code-block:: cpp
	:class: doxyrest-title-code-block

	desc(
		:ref:`prop_kind<doxid-group__dnnl__api__attributes_1gac7db48f6583aa9903e54c2a39d65438f>` aprop_kind,
		:ref:`rnn_direction<doxid-group__dnnl__api__rnn_1ga33315cf335d1cbe26fd6b70d956e23d5>` direction,
		const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& src_layer_desc,
		const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& src_iter_desc,
		const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& src_iter_c_desc,
		const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& weights_layer_desc,
		const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& weights_iter_desc,
		const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& weights_peephole_desc,
		const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& bias_desc,
		const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& dst_layer_desc,
		const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& dst_iter_desc,
		const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& dst_iter_c_desc,
		:ref:`rnn_flags<doxid-group__dnnl__api__rnn_1gad27d0db2a86ae3072207769f5c2ddd1e>` flags = :ref:`rnn_flags::undef<doxid-group__dnnl__api__rnn_1ggad27d0db2a86ae3072207769f5c2ddd1eaf31ee5e3824f1f5e5d206bdf3029f22b>`
		)

Constructs a descriptor for an LSTM (with or without peephole) forward propagation primitive.

The following arguments may point to a zero memory descriptor:

* ``src_iter_desc`` together with ``src_iter_c_desc``,

* ``weights_peephole_desc``,

* ``bias_desc``,

* ``dst_iter_desc`` together with ``dst_iter_c_desc``.

This would then indicate that the LSTM forward propagation primitive should not use them and should default to zero values instead.

.. note:: 

   All memory descriptors can be initialized with an :ref:`dnnl::memory::format_tag::any <doxid-structdnnl_1_1memory_1a8e71077ed6a5f7fb7b3e6e1a5a2ecf3fa100b8cad7cf2a56f6df78f171f97a1ec>` value of ``format_tag``.



.. rubric:: Parameters:

.. list-table::
	:widths: 20 80

	*
		- aprop_kind

		- Propagation kind. Possible values are :ref:`dnnl::prop_kind::forward_training <doxid-group__dnnl__api__attributes_1ggac7db48f6583aa9903e54c2a39d65438fa24775787fab8f13aa4809e1ce8f82aeb>`, and :ref:`dnnl::prop_kind::forward_inference <doxid-group__dnnl__api__attributes_1ggac7db48f6583aa9903e54c2a39d65438fa3b9fad4f80d45368f856b5403198ac4c>`.

	*
		- direction

		- RNN direction. See :ref:`dnnl::rnn_direction <doxid-group__dnnl__api__rnn_1ga33315cf335d1cbe26fd6b70d956e23d5>` for more info.

	*
		- src_layer_desc

		- Memory descriptor for the input vector.

	*
		- src_iter_desc

		- Memory descriptor for the input recurrent hidden state vector.

	*
		- src_iter_c_desc

		- Memory descriptor for the input recurrent cell state vector.

	*
		- weights_layer_desc

		- Memory descriptor for the weights applied to the layer input.

	*
		- weights_iter_desc

		- Memory descriptor for the weights applied to the recurrent input.

	*
		- weights_peephole_desc

		- Memory descriptor for the weights applied to the cell states (according to the Peephole LSTM formula).

	*
		- bias_desc

		- Bias memory descriptor.

	*
		- dst_layer_desc

		- Memory descriptor for the output vector.

	*
		- dst_iter_desc

		- Memory descriptor for the output recurrent hidden state vector.

	*
		- dst_iter_c_desc

		- Memory descriptor for the output recurrent cell state vector.

	*
		- flags

		- Unused.

.. index:: pair: function; desc
.. _doxid-structdnnl_1_1lstm__forward_1_1desc_1a2d895c8ee23f15cbfb2cd6b67551673f:

.. ref-code-block:: cpp
	:class: doxyrest-title-code-block

	desc(
		:ref:`prop_kind<doxid-group__dnnl__api__attributes_1gac7db48f6583aa9903e54c2a39d65438f>` aprop_kind,
		:ref:`rnn_direction<doxid-group__dnnl__api__rnn_1ga33315cf335d1cbe26fd6b70d956e23d5>` direction,
		const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& src_layer_desc,
		const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& src_iter_desc,
		const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& src_iter_c_desc,
		const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& weights_layer_desc,
		const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& weights_iter_desc,
		const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& bias_desc,
		const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& dst_layer_desc,
		const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& dst_iter_desc,
		const :ref:`memory::desc<doxid-structdnnl_1_1memory_1_1desc>`& dst_iter_c_desc,
		:ref:`rnn_flags<doxid-group__dnnl__api__rnn_1gad27d0db2a86ae3072207769f5c2ddd1e>` flags = :ref:`rnn_flags::undef<doxid-group__dnnl__api__rnn_1ggad27d0db2a86ae3072207769f5c2ddd1eaf31ee5e3824f1f5e5d206bdf3029f22b>`
		)

Constructs a descriptor for an LSTM forward propagation primitive.

The following arguments may point to a zero memory descriptor:

* ``src_iter_desc`` together with ``src_iter_c_desc``,

* ``bias_desc``,

* ``dst_iter_desc`` together with ``dst_iter_c_desc``.

This would then indicate that the LSTM forward propagation primitive should not use them and should default to zero values instead.

.. note:: 

   All memory descriptors can be initialized with an :ref:`dnnl::memory::format_tag::any <doxid-structdnnl_1_1memory_1a8e71077ed6a5f7fb7b3e6e1a5a2ecf3fa100b8cad7cf2a56f6df78f171f97a1ec>` value of ``format_tag``.



.. rubric:: Parameters:

.. list-table::
	:widths: 20 80

	*
		- aprop_kind

		- Propagation kind. Possible values are :ref:`dnnl::prop_kind::forward_training <doxid-group__dnnl__api__attributes_1ggac7db48f6583aa9903e54c2a39d65438fa24775787fab8f13aa4809e1ce8f82aeb>`, and :ref:`dnnl::prop_kind::forward_inference <doxid-group__dnnl__api__attributes_1ggac7db48f6583aa9903e54c2a39d65438fa3b9fad4f80d45368f856b5403198ac4c>`.

	*
		- direction

		- RNN direction. See :ref:`dnnl::rnn_direction <doxid-group__dnnl__api__rnn_1ga33315cf335d1cbe26fd6b70d956e23d5>` for more info.

	*
		- src_layer_desc

		- Memory descriptor for the input vector.

	*
		- src_iter_desc

		- Memory descriptor for the input recurrent hidden state vector.

	*
		- src_iter_c_desc

		- Memory descriptor for the input recurrent cell state vector.

	*
		- weights_layer_desc

		- Memory descriptor for the weights applied to the layer input.

	*
		- weights_iter_desc

		- Memory descriptor for the weights applied to the recurrent input.

	*
		- bias_desc

		- Bias memory descriptor.

	*
		- dst_layer_desc

		- Memory descriptor for the output vector.

	*
		- dst_iter_desc

		- Memory descriptor for the output recurrent hidden state vector.

	*
		- dst_iter_c_desc

		- Memory descriptor for the output recurrent cell state vector.

	*
		- flags

		- Unused.