/*******************************************************************************
* Copyright 2016-2018 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.
*******************************************************************************/

#ifndef MKLDNN_TYPES_H
#define MKLDNN_TYPES_H

#ifdef __cplusplus
extern "C" {
#endif

#ifndef DOXYGEN_SHOULD_SKIP_THIS
#include <stddef.h>
#include <stdint.h>
#endif

/** @addtogroup c_api C API
 *  @{
 *
 *  @addtogroup c_api_types Types
 *  @{
 *
 *  @addtogroup c_api_types_generic Generic
 *  @{ */

/** Status values returned by Intel(R) MKL-DNN functions. */
typedef enum {
    /** The operation was successful */
    mkldnn_success = 0,
    /** The operation failed due to an out-of-memory condition */
    mkldnn_out_of_memory = 1,
    /** The operation failed and should be retried */
    mkldnn_try_again = 2,
    /** The operation failed because of incorrect function arguments  */
    mkldnn_invalid_arguments = 3,
    /** The operation failed because a primitive was not ready for execution */
    mkldnn_not_ready = 4,
    /** The operation failed because requested functionality is not implemented
     */
    mkldnn_unimplemented = 5,
    /** Primitive iterator passed over last primitive descriptor */
    mkldnn_iterator_ends = 6,
    /** Primitive or engine failed on execution */
    mkldnn_runtime_error = 7,
    /** Queried element is not required for given primitive */
    mkldnn_not_required = 8,
} mkldnn_status_t;

/** Data type specification */
typedef enum {
    /** Undefined data type, used for empty memory descriptors. */
    mkldnn_data_type_undef = 0,
    /** 32-bit/single-precision floating point. */
    mkldnn_f32 = 1,
    /** 32-bit signed integer. */
    mkldnn_s32 = 2,
    /** 16-bit signed integer. */
    mkldnn_s16 = 4,
    /** 8-bit signed integer. */
    mkldnn_s8 = 5,
    /** 8-bit unsigned integer. */
    mkldnn_u8 = 6,
} mkldnn_data_type_t;

/** Rounding mode */
typedef enum {
    /** Round nearest */
    mkldnn_round_nearest = 1,
    /** Round down */
    mkldnn_round_down = 2,
} mkldnn_round_mode_t;

/** Memory format specification.
 *
 * Intel(R) MKL-DNN uses the following notation for memory format names:
 *  - @c 'n' denotes the mini-batch dimension
 *  - @c 'c' denotes a channels dimension
 *  - When there are multiple channel dimensions (for example, in convolution
 *    weights tensor), @c 'i' and @c 'o' denote dimensions of input and output
 *    channels
 *  - @c 'h' and @c 'w' denote spatial width and height
 *  - Upper-case letters indicate that the data is laid out in blocks
 *    for a particular dimension. In such cases, the format name contains both
 *    upper- and lower-case letters for that dimension with lower-case letter
 *    preceded by the block size. For example: @c 'mkldnn_nChw8c' describes a
 *    format where the outermost dimension is mini-batch, followed by the
 *    channel block number, followed by the spatial height and width, and
 *    finally followed by 8-element channel blocks.
 *
 * @note
 *    Channel designations can be different. For example: both the @c
 *    'mkldnn_nc' and @c 'mkldnn_io' formats can be used to describe a 2D
 *    tensor.
 */
typedef enum {
    /** Undefined memory format, used for empty memory descriptors. */
    mkldnn_format_undef = 0,
    /** Unspecified format. The primitive selects a format
     * automatically. */
    mkldnn_any,
    /** A tensor in a generic format described by the stride and blocking
     * values in each dimension. See #mkldnn_blocking_desc_t for more
     * information. */
    mkldnn_blocked,
    /** 1D data tensor. */
    mkldnn_x,
    /** 2D data tensor. */
    mkldnn_nc,
    /** 4D data tensor in the @c nchw format typically used in Caffe. */
    mkldnn_nchw,
    /** 4D data tensor in the @c nhwc format typically used in TensorFlow. */
    mkldnn_nhwc,
    /** 4D data tensor in the @c chwn format typically used in Neon. */
    mkldnn_chwn,
    /** 4D data tensor in the @c nchw format with channels data laid out in
     * memory in 8-element blocks. */
    mkldnn_nChw8c,
    /** 4D data tensor in the @c nchw format with channels data laid out in
     * memory in 16-element blocks. */
    mkldnn_nChw16c,
    /** 5D data tensor in the @c ncdhw format. */
    mkldnn_ncdhw,
    /** 5D data tensor in the @c ndhwc format typically used in TensorFlow. */
    mkldnn_ndhwc,
    /** 5D data tensor in the @c ncdhw format with channels data laid out in
     * memory in 16-element blocks. */
    mkldnn_nCdhw16c,
    /** 2D weights tensor in the format (input channels, output channels). */
    mkldnn_oi,
    /** 2D weights tensor in the format (input channels, output channels). */
    mkldnn_io,
    /** 4D weights tensor in the format (input channels, output channels,
     * width, height). */
    mkldnn_oihw,
    /** 4D weights tensor in the format (input channels, height, width,
     * output channels). */
    mkldnn_ihwo,
    /** 4D weights tensor in the format (height, width, input channels,
     * output channels). */
    mkldnn_hwio,
    /** 5D weights tensor in the format (depth, height, width, input channels,
     * output channels). */
    mkldnn_dhwio,
    /** 5D weight tensor in the @c oidhw format. */
    mkldnn_oidhw,
   /** 6D weights tensor in the @c oidhw format with output channels data
    * laid out in memory in 16-element blocks and input channels data
     * laid out in memory in 4-element blocks blocked by quadruple. */
    mkldnn_OIdhw16i16o,
    /** 6D weights tensor in the @c oihw format with both input and output
     * channels data laid out in memory in 16-element blocks. */
    mkldnn_OIdhw16o16i,
    /** 5D weights tensor in the blocked version of @c oidhw format with output
     * channels data laid out in memory in 16-element blocks. */
    mkldnn_Oidhw16o,
    /** 5D weights tensor in the blocked version of @c oidhw format with output
     * channels data laid out in memory in 16-element blocks. */
    mkldnn_Odhwi16o,
    /** 4D weights tensor in the @c oihw format with both input and output
     * channels data laid out in memory in 8-element blocks. */
    mkldnn_OIhw8i8o,
    /** 4D weights tensor in the @c oihw format with both input and output
     * channels data laid out in memory in 16-element blocks. */
    mkldnn_OIhw16i16o,
    /** 4D weights tensor in the @c oihw format with output channels data
     * laid out in memory in 16-element blocks and input channels data
     * laid out in memory in 4-element blocks blocked by quadruple. */
    mkldnn_OIhw4i16o4i,
    /** 4D weights tensor in the @c oihw format with output channels data
     * laid out in memory in 16-element blocks and input channels data
     * laid out in memory in 8-element blocks blocked by pairs. */
    mkldnn_OIhw8i16o2i,
    /** 5D weights tensor in the @c oidhw format with output channels data
     * laid out in memory in 16-element blocks and input channels data
     * laid out in memory in 8-element blocks blocked by pairs. */
    mkldnn_OIdhw8i16o2i,
    /** 4D weights tensor in the @c oihw format with input channels data
     * laid out in memory in 16-element blocks and output channels data
     * laid out in memory in 8-element blocks blocked by pairs. */
    mkldnn_OIhw8o16i2o,
    /** 4D weights tensor in the @c oihw format with both input and output
     * channels data laid out in memory in 8-element blocks. */
    mkldnn_OIhw8o8i,
    /** 4D weights tensor in the @c oihw format with both input and output
     * channels data laid out in memory in 16-element blocks. */
    mkldnn_OIhw16o16i,
    /** 4D weights tensor in the @c oihw format with both input and output
     * channels data laid out in memory in 16-element blocks. */
    mkldnn_IOhw16o16i,
    /** 4D weights tensor in the format (output channels, input channels,
     * height, width) with output channels data laid out in memory in 8-element
     * blocks. */
    mkldnn_Oihw8o,
    /** 4D weights tensor in the format (output channels, input channels,
     * height, width) with output channels data laid out in memory in
     * 16-element blocks. */
    mkldnn_Oihw16o,
    /** 4D weights tensor in the format (output channels, width, height, input
     * channels) with output channels data laid out in memory in 8-element
     * blocks. */
    mkldnn_Ohwi8o,
    /** 4D weights tensor in the format (output channels, width, height, input
     * channels) with output channels data laid out in memory in 16-element
     * blocks. */
    mkldnn_Ohwi16o,
    /** 4D weights tensor in the @c oihw format with both input and output
     * channels data laid out in memory in 16-element and 4-element blocks. */
    mkldnn_OhIw16o4i,
    /** 5D weights tensor in the @c oihw format with extra outer dimension for
     * groups. */
    mkldnn_goihw,
    /** 5D weights tensor in the @c hwio format with extra dimension for
     * groups that comes after the output channels. */
    mkldnn_hwigo,
    /** 5D weights tensor in the blocked version of @c goihw format with both
     * input and output channels data laid out in memory in 8-element blocks.
     */
    mkldnn_gOIhw8i8o,
    /** 5D weights tensor in the blocked version of @c goihw format with both
     * input and output channels data laid out in memory in 16-element blocks.
     */
    mkldnn_gOIhw16i16o,
    /** 5D weights tensor in the @c oihw format with output channels data
     * laid out in memory in 16-element blocks and input channels data
     * laid out in memory in 4-element blocks blocked by quadruple. */
    mkldnn_gOIhw4i16o4i,
    /** 5D weights tensor in the @c oihw format with output channels data
     * laid out in memory in 16-element blocks and input channels data
     * laid out in memory in 8-element blocks blocked by pairs. */
    mkldnn_gOIhw8i16o2i,
    /** 6D weights tensor in the @c oidhw format with output channels data
     * laid out in memory in 16-element blocks and input channels data
     * laid out in memory in 8-element blocks blocked by pairs. */
    mkldnn_gOIdhw8i16o2i,
    /** 5D weights tensor in the @c oihw format with input channels data
     * laid out in memory in 16-element blocks and output channels data
     * laid out in memory in 8-element blocks blocked by pairs. */
    mkldnn_gOIhw8o16i2o,
    /** 5D weights tensor in the blocked version of @c goihw format with both
     * input and output channels data laid out in memory in 8-element blocks.
     */
    mkldnn_gOIhw8o8i,
    /** 5D weights tensor in the blocked version of @c goihw format with both
     * input and output channels data laid out in memory in 16-element blocks.
     */
    mkldnn_gOIhw16o16i,
    /** 5D weights tensor in the blocked version of @c goihw format with both
     * input and output channels data laid out in memory in 16-element blocks.
     */
    mkldnn_gIOhw16o16i,
    /** 5D weights tensor in the blocked version of @c goihw format with output
     * channels data laid out in memory in 8-element blocks. */
    mkldnn_gOihw8o,
    /** 5D weights tensor in the blocked version of @c goihw format with output
     * channels data laid out in memory in 16-element blocks. */
    mkldnn_gOihw16o,
    /** 5D weights tensor in the blocked version of @c goihw format with output
     * channels data laid out in memory in 8-element blocks. */
    mkldnn_gOhwi8o,
    /** 5D weights tensor in the blocked version of @c goihw format with output
     * channels data laid out in memory in 16-element blocks. */
    mkldnn_gOhwi16o,
    /** 5D weights tensor in the blocked version of @c goihw format with group
     * data laid out in memory in 8-element blocks. */
    mkldnn_Goihw8g,
    /** 5D weights tensor in the blocked version of @c goihw format with group
     * data laid out in memory in 16-element blocks. */
    mkldnn_Goihw16g,
    /** 5D weights tensor in the @c goihw format with both input and output
     * channels data laid out in memory in 16-element and 4-element blocks. */
    mkldnn_gOhIw16o4i,
    /** 6D weight tensor in the @c goidhw format with extra dimension for
     * groups */
    mkldnn_goidhw,
   /** 6D weights tensor in the @c oidhw format with output channels data
    * laid out in memory in 16-element blocks and input channels data
     * laid out in memory in 4-element blocks blocked by quadruple. */
    mkldnn_gOIdhw16i16o,
    /** 6D weights tensor in the blocked version of @c goihw format with both
     * input and output channels data laid out in memory in 16-element blocks.
     */
    mkldnn_gOIdhw16o16i,
    /** 6D weights tensor in the blocked version of @c goidhw format with output
     * channels data laid out in memory in 16-element blocks. */
    mkldnn_gOidhw16o,
    /** 6D weights tensor in the blocked version of @c goidhw format with output
     * channels data laid out in memory in 16-element blocks. */
    mkldnn_gOdhwi16o,
    /** 3D data tensor in the format (batch, seq_length, input channels). */
    mkldnn_ntc,
    /** 3D data tensor in the format (seq_length, batch, input channels). */
    mkldnn_tnc,
    /** 5D states tensor in the format (num_layers, num_directions, num_states,
     * batch, state channels). */
    mkldnn_ldsnc,
    /** 5D weights tensor in the format (num_layers, num_directions,
     *  input_chanels, num_gates, output_channels). */
    mkldnn_ldigo,
    /** 5D weights tensor in the blocked format. */
    mkldnn_ldigo_p,
    /** 5D weights tensor in the format (num_layers, num_directions, num_gates,
     *  output_channels, input_chanels). */
    mkldnn_ldgoi,
    /** 5D weights tensor in the blocked format. */
    mkldnn_ldgoi_p,
    /** 4D bias tensor in the format (num_layers, num_directions, num_gates,
     * output_channels). */
    mkldnn_ldgo,
    /** General tensor format for integer 8bit winograd convolution. */
    mkldnn_wino_fmt,
    /** Just a sentinel, not real memory format. Must be changed after new
     * format is added. */
    mkldnn_format_last,
    /** 4D weights tensor in the oihw format with input channels data laid out
     * in memory in 8-element blocks. */
    mkldnn_oIhw8i = mkldnn_nChw8c,
    /** 4D weights tensor in the oihw format with input channels data laid out
     * in memory in 16-element blocks. */
    mkldnn_oIhw16i = mkldnn_nChw16c,
} mkldnn_memory_format_t;

/** Kinds of padding. Define how to interpret the data in padding regions. */
typedef enum {
    /** The data in padding regions is zero. */
    mkldnn_padding_zero,
} mkldnn_padding_kind_t;

/** Kinds of propagation. */
typedef enum {
    /* TODO: suggest renames */
    /** Undefined propagation type. */
    mkldnn_prop_kind_undef = 0,
    /** Forward data propagation (training mode). In this mode primitives
     * perform computations necessary for subsequent backward propagation. */
    mkldnn_forward_training = 64,
    /** Forward data propagation (inference mode). In this mode primitives only
     * perform computations that are necessary for inference and omit
     * computations that are only necessary for backward propagation. */
    mkldnn_forward_inference = 96,
    /** Forward data propagation (alias for @c mkldnn_forward_inference) */
    mkldnn_forward_scoring = mkldnn_forward_inference,
   /** Forward data propagation (alias for @c mkldnn_forward_training) */
    mkldnn_forward = mkldnn_forward_training,
    /** Backward propagation (with respect to all parameters */
    mkldnn_backward = 128,
    /** Backward data propagation */
    mkldnn_backward_data = 160,
    /** Backward weights propagation */
    mkldnn_backward_weights = 192,
    /** Backward bias propagation */
    mkldnn_backward_bias = 193,
} mkldnn_prop_kind_t;

/** Kinds of primitives. Used to implement a way to extend the library with new
 * primitives without changing the ABI. */
typedef enum {
    /** Undefined primitive (XXX: why do we have it?). */
    mkldnn_undefined_primitive,
    /** A memory primitive. */
    mkldnn_memory,
    /** A view primitive. */
    mkldnn_view,
    /** A reorder primitive.*/
    mkldnn_reorder,
    /** A (out-of-place) concat primitive. */
    mkldnn_concat,
    /** A (in-place) concat primitive. */
    mkldnn_concat_inplace,
    /** A sum primitive. */
    mkldnn_sum,
    /** A convolution primitive. */
    mkldnn_convolution,
    /** A deconvolution primitive. */
    mkldnn_deconvolution,
    /** An element-wise primitive. */
    mkldnn_eltwise,
    /** A ReLU primitive. @deprecated */
    mkldnn_relu = mkldnn_eltwise,
    /** A Softmax primitive. */
    mkldnn_softmax,
    /** A pooling primitive. */
    mkldnn_pooling,
    /** An LRN primitive. */
    mkldnn_lrn,
    /** An batch normalization primitive. */
    mkldnn_batch_normalization,
    /** An inner product primitive. */
    mkldnn_inner_product,
    /** A convolution primitive merged with ReLU. @deprecated */
    mkldnn_convolution_relu,
    /** A rnn primitive. */
    mkldnn_rnn,
    /** A ROI pooling primitive. */
    mkldnn_roi_pooling,
    /** An channel-wise primitive. */
    mkldnn_depthwise,
} mkldnn_primitive_kind_t;

/** Kinds of algorithms. */
typedef enum {
    mkldnn_alg_kind_undef,
    /** Direct convolution */
    mkldnn_convolution_direct = 1,
    /** Winograd convolution */
    mkldnn_convolution_winograd = 2,
    /** Eltwise: ReLU */
    mkldnn_eltwise_relu = 8,
    /** Eltwise: hyperbolic tangent non-linearity (tanh) */
    mkldnn_eltwise_tanh = 9,
    /** Eltwise: parametric exponential linear unit (elu) */
    mkldnn_eltwise_elu = 10,
    /** Eltwise: square */
    mkldnn_eltwise_square = 11,
    /** Eltwise: abs */
    mkldnn_eltwise_abs = 12,
    /** Eltwise: square root */
    mkldnn_eltwise_sqrt = 13,
    /** Eltwise: linear */
    mkldnn_eltwise_linear = 14,
    /** Eltwise: bounded_relu */
    mkldnn_eltwise_bounded_relu = 15,
    /** Eltwise: soft_relu */
    mkldnn_eltwise_soft_relu = 16,
    /** Eltwise: logistic */
    mkldnn_eltwise_logistic = 17,
    /** Eltwise: clamp */
    mkldnn_eltwise_clamp = 18,
    /** Max pooling */
    mkldnn_pooling_max = 34,
    /** Average pooling include padding */
    mkldnn_pooling_avg_include_padding = 40,
    /** Average pooling exclude padding */
    mkldnn_pooling_avg_exclude_padding = 41,
    mkldnn_pooling_avg = mkldnn_pooling_avg_exclude_padding,
    /** Local response normalization (LRN) across multiple channels */
    mkldnn_lrn_across_channels = 65,
    /** LRN within a single channel */
    mkldnn_lrn_within_channel = 66,
    /** Direct deconvolution */
    mkldnn_deconvolution_direct = 71,
    /** Winograd deconvolution */
    mkldnn_deconvolution_winograd = 72,
    /** RNN cell */
    mkldnn_vanilla_rnn = 80,
    /** LSTM cell */
    mkldnn_vanilla_lstm = 81,
    /** GRU cell */
    mkldnn_vanilla_gru = 82,
    /** GRU cell with linear before reset
     *
     * Modification of original GRU cell. Differs from #mkldnn_vanilla_gru
     * in how the new memory gate is calculated:
     * \f[ c_t = tanh(W_c*x_t + b_{c_h} + r_t*(U_c*h_{t-1}+b_{c_h})) \f]
     * Primitive expects 4 biases on input:
     * \f$[b_{u}, b_{r}, b_{c_x}, b_{c_h}]\f$
     * */
    mkldnn_gru_linear_before_reset = 83,
    /** Depthwise: scale_shift */
    mkldnn_depthwise_scale_shift = 100,
    /** Depthwise: prelu */
    mkldnn_depthwise_prelu = 101,
    /** ROI max pooling **/
    mkldnn_roi_pooling_max = 128,
    /** ROI pooling with bilinear interpolation**/
    mkldnn_roi_pooling_bilinear = 129
} mkldnn_alg_kind_t;

/** Flags for batch-normalization primititve. */
typedef enum {
    /** Use global statistics
     *
     * If specified
     *  - on forward propagation use mean and variance provided by user (input)
     *  - on backward propagation reduces the amount of computations, since
     *    mean and variance are considered as constants
     *
     *  If not specified:
     *   - on forward propagation mean and variance are computed and stored in
     *     output
     *   - on backward propagation compute full derivative wrt to data
     */
    mkldnn_use_global_stats = 0x1U,
    /** Use scale and shift parameters
     *
     * If specified:
     *  - on forward propagation use scale and shift (aka scale and bias) for
     *    the batch normalization results
     *  - on backward propagation (for prop_kind == #mkldnn_backward) compute
     *    diff wrt to scale and shift (hence one extra output used)
     *
     * If no specified:
     *  - on backward propagation prop_kind == #mkldnn_backward_data has the
     *    same behavior as prop_kind == #mkldnn_backward
     */
    mkldnn_use_scaleshift = 0x2U,
    /** Omit statistics
     *
     * @deprecated use #mkldnn_use_global_stats instead
     *
     * For time being had an affect on backward propagation only which allowed
     * skipping some computations (the same semantics as
     * #mkldnn_use_global_stats)
     */
    mkldnn_omit_stats = mkldnn_use_global_stats,
    /** Fuse with ReLU
     *
     * If specified:
     *  - on inference this option behaves the same as if the primitive were
     *    fused with ReLU via post ops API
     *  - on training primitive requires workspace (required to be able to
     *    perform backward pass)
     */
    mkldnn_fuse_bn_relu = 0x4U,
} mkldnn_batch_normalization_flag_t;

/** @} */

/** @addtogroup c_api_types_memory Auxiliary types for memory description
 *  @{ */

/** Maximum number of dimensions a tensor can have. Only restricts the amount
 * of space used for the tensor description. Individual computational
 * primitives may support only tensors of certain dimensions. */
#define TENSOR_MAX_DIMS 12

/** A type to describe tensor dimensions. */
typedef int mkldnn_dims_t[TENSOR_MAX_DIMS];
/** A type to describe strides within a tensor. */
typedef ptrdiff_t mkldnn_strides_t[TENSOR_MAX_DIMS];

/** Generic description of blocked data layout for most memory formats. */
typedef struct {
    /** Block size for each of the dimensions. */
    mkldnn_dims_t block_dims;
    /** strides[0]: stride between the first elements of adjacent blocks.
     * @n strides[1]: strides between elements in the same block. */
    mkldnn_strides_t strides[2];
    /** Size of the data including padding in each dimension. */
    mkldnn_dims_t padding_dims;
    /** Per-dimension offset from the padding to actual data, the top-level
     * tensor with offsets applied must lie within the padding area. */
    mkldnn_dims_t offset_padding_to_data;
    /** Offset from memory origin to the current block, non-zero only in
     * a description of a memory sub-block. */
    ptrdiff_t offset_padding;
} mkldnn_blocking_desc_t;

typedef enum {
    /** Undefined memory format, used for empty memory descriptors. */
    mkldnn_wino_undef = 0,
    /** Tensor of weights for integer 8bit winograd convolution. */
    mkldnn_wino_wei_aaOIoi
} mkldnn_wino_memory_format_t;

/** Description of tensor of weights for integer 8bit winograd convolution. */
typedef struct {
    mkldnn_wino_memory_format_t wino_format;
    int m;
    int r;
    int alpha;
    int nb_ic;
    int nb_oc;
    int ic_block;
    int oc_block;
    size_t size;
} mkldnn_wino_desc_t;

/** @addtogroup c_api_types_op_descs Operation descriptors
 *  @{*/

/** A pointer to any of the operation descriptors. */
typedef void *mkldnn_op_desc_t;
/** A pointer to any of the operation descriptors (constant variant). */
typedef const void *const_mkldnn_op_desc_t;

/** Memory descriptor. The description is based on a number of dimensions,
 * dimensions themselves, plus information about elements type and memory
 * format. Additionally, contains format-specific descriptions of the data
 * layout. */
typedef struct {
    /** The kind of primitive. Used for self identifying the primitive
     * descriptor. Must be #mkldnn_memory. */
    mkldnn_primitive_kind_t primitive_kind;
    /** Number of dimensions */
    int ndims;
    /** Dimensions in the following order: mini-batch, channel, spatial. For
     * example: <code>{N, C, H, W}</code>. */
    mkldnn_dims_t dims;
    /** Data type of the tensor elements. */
    mkldnn_data_type_t data_type;
    /** Memory format. */
    mkldnn_memory_format_t format;
    union {
        /** Description of the data layout for memory formats that use
         * blocking. */
        mkldnn_blocking_desc_t blocking;
        /** Tensor of weights for integer 8bit winograd convolution. */
        mkldnn_wino_desc_t wino_desc;
        /* ... other descriptions possible */
    } layout_desc;
} mkldnn_memory_desc_t;

/** @} */

/** A descriptor of a convolution operation. */
typedef struct {
    /** The kind of primitive. Used for self identifying the primitive
     * descriptor. Must be #mkldnn_convolution. */
    mkldnn_primitive_kind_t primitive_kind;
    /** The kind of propagation. Possible values: #mkldnn_forward_training,
     * #mkldnn_forward_inference, #mkldnn_backward_data,
     * #mkldnn_backward_weights, and #mkldnn_backward_bias. */
    mkldnn_prop_kind_t prop_kind;
    /** The kind of the convolution algorithm. Possible values:
     * #mkldnn_convolution_direct. */
    mkldnn_alg_kind_t alg_kind;
    /** Source memory descriptor. */
    mkldnn_memory_desc_t src_desc;
    /** Source gradient memory descriptor. */
    mkldnn_memory_desc_t diff_src_desc;
    /** Weights memory descriptor. */
    mkldnn_memory_desc_t weights_desc;
    /** Weights gradient memory descriptor. */
    mkldnn_memory_desc_t diff_weights_desc;
    /** Bias memory descriptor. */
    mkldnn_memory_desc_t bias_desc;
    /** Bias gradient memory descriptor. */
    mkldnn_memory_desc_t diff_bias_desc;
    /** Destination memory descriptor. */
    mkldnn_memory_desc_t dst_desc;
    /** Destination gradient memory descriptor. */
    mkldnn_memory_desc_t diff_dst_desc;
    /** Convolution strides in each spatial dimension. */
    mkldnn_dims_t strides;
    /** Convolution dilates in each spatial dimension. */
    mkldnn_dims_t dilates;
    /** Padding in each spatial dimension. padding[0] is a padding in the
     * beginning (@p padding_l), padding[1] is a padding in the end (@p
     * padding_r). */
    mkldnn_dims_t padding[2];
    /** The kind of padding to use. */
    mkldnn_padding_kind_t padding_kind;
    /** The accumulator data type. Initialized automatically. */
    mkldnn_data_type_t accum_data_type;
} mkldnn_convolution_desc_t;

/** A descriptor of a deconvolution operation. */
typedef mkldnn_convolution_desc_t mkldnn_deconvolution_desc_t;

/** A descriptor of a element-wise operation. */
typedef struct {
    /** The kind of primitive. Used for self identifying the primitive
     * descriptor. Must be #mkldnn_eltwise. */
    mkldnn_primitive_kind_t primitive_kind;
    /** The kind of propagation. Possible values: #mkldnn_forward_training,
     * #mkldnn_forward_inference, #mkldnn_backward, and #mkldnn_backward_data.
     */
    mkldnn_prop_kind_t prop_kind;
    /** The kind of eltwise algorithm. Possible values: #mkldnn_eltwise_relu,
     * #mkldnn_eltwise_tanh, #mkldnn_eltwise_elu, #mkldnn_eltwise_square,
     * #mkldnn_eltwise_abs, #mkldnn_eltwise_sqrt, #mkldnn_eltwise_linear,
     * #mkldnn_eltwise_bounded_relu, #mkldnn_eltwise_soft_relu,
     * #mkldnn_eltwise_logistic. */
    mkldnn_alg_kind_t alg_kind;
    /** Source and destination memory descriptor. */
    mkldnn_memory_desc_t data_desc;
    /** Source and destination gradient memory descriptor. */
    mkldnn_memory_desc_t diff_data_desc;
    /** Algorithm specific parameter.
     * Accordance table:
     *  - #mkldnn_eltwise_relu: @p alpha -- negative slope, @p beta ignored
     *  - #mkldnn_eltwise_tanh: @p alpha and @p beta ignored
     *  - #mkldnn_eltwise_elu: @p alpha -- negative slope, @p beta ignored
     *  - #mkldnn_eltwise_square: @p alpha and @p beta ignored
     *  - #mkldnn_eltwise_abs: @p alpha and @p beta ignored
     *  - #mkldnn_eltwise_sqrt: @p alpha and @p beta ignored
     *  - #mkldnn_eltwise_linear: @p alpha -- scale, @p beta -- shift
     *  - #mkldnn_eltwise_bounded_relu: @p alpha -- upper bound, @p beta ignored
     *  - #mkldnn_eltwise_soft_relu: @p alpha and @p beta ignored
     *  - #mkldnn_eltwise_logistic: @p alpha and @p beta ignored
     */
    float alpha, beta;
    /** ReLU scaling factor for negative values.
     * @deprecated: use alpha instead
     * @warning: read-only value */
    float negative_slope;
} mkldnn_eltwise_desc_t;

/** A descriptor of a channel-wise operation. */
typedef struct {
    /** The kind of primitive. Used for self identifying the primitive
     * descriptor. Must be #mkldnn_depthwise. */
    mkldnn_primitive_kind_t primitive_kind;
    /** The kind of propagation. Possible values: #mkldnn_forward_training,
     * #mkldnn_forward_inference, #mkldnn_backward, and #mkldnn_backward_data.
     */
    mkldnn_prop_kind_t prop_kind;
    /** The kind of depthwise algorithm. Possible values: #mkldnn_depthwise_scale_shift
     * #mkldnn_depthwise_prelu */
    mkldnn_alg_kind_t alg_kind;
    /** Source memory descriptor. */
    mkldnn_memory_desc_t src_desc;
    /** Destination memory descriptor. */
    mkldnn_memory_desc_t dst_desc;
    /** Weights memory descriptor. */
    mkldnn_memory_desc_t weights_desc;
    /** Bias memory descriptor. */
    mkldnn_memory_desc_t bias_desc;
} mkldnn_depthwise_desc_t;

/* @deprecated: use mkldnn_eltwise_desc_t */
typedef mkldnn_eltwise_desc_t mkldnn_relu_desc_t;

/** A descriptor of a Softmax operation. */
typedef struct {
    /** The kind of primitive. Used for self identifying the primitive
    * descriptor. Must be #mkldnn_softmax. */
    mkldnn_primitive_kind_t primitive_kind;
    /** The kind of propagation. Possible values: #mkldnn_forward_training,
     * #mkldnn_forward_inference. */
    mkldnn_prop_kind_t prop_kind;
    /** Source and destination memory descriptor. */
    mkldnn_memory_desc_t data_desc;
    /** Source and Destination of gradient memory descriptor. */
    mkldnn_memory_desc_t diff_desc;
    /** The axis along which to perform the softmax. */
    int softmax_axis;
} mkldnn_softmax_desc_t;

/** A descriptor of a pooling operation. */
typedef struct {
    /** The kind of primitive. Used for self identifying the primitive
     * descriptor. Must be #mkldnn_pooling. */
    mkldnn_primitive_kind_t primitive_kind;
    /** The kind of propagation. Possible values: #mkldnn_forward_training,
     * #mkldnn_forward_inference, #mkldnn_backward, and #mkldnn_backward_data.
     */
    mkldnn_prop_kind_t prop_kind;
    /** The kind of pooling algorithm. Possible values: #mkldnn_pooling_max,
     * #mkldnn_pooling_avg. */
    mkldnn_alg_kind_t alg_kind;
    /** Source memory descriptor. */
    mkldnn_memory_desc_t src_desc;
    /** Source gradient memory descriptor. */
    mkldnn_memory_desc_t diff_src_desc;
    /** Destination memory descriptor. */
    mkldnn_memory_desc_t dst_desc;
    /** Destination gradient memory descriptor. */
    mkldnn_memory_desc_t diff_dst_desc;
    /** Pooling kernel strides for spatial dimensions. */
    mkldnn_dims_t strides;
    /** Pooling kernel spatial dimensions. */
    mkldnn_dims_t kernel;
    /** Padding in each spatial dimension. padding[0] is a padding in the
     * beginning (@p padding_l), padding[1] is a padding in the end (@p
     * padding_r). */
    mkldnn_dims_t padding[2];
    /** The kind of padding to use. */
    mkldnn_padding_kind_t padding_kind;
    /** The accumulator data type. Initialized automatically. */
    mkldnn_data_type_t accum_data_type;
} mkldnn_pooling_desc_t;

/** A descriptor of a Local Response Normalization (LRN) operation. */
typedef struct {
    /** The kind of primitive. Used for self identifying the primitive
     * descriptor. Must be #mkldnn_lrn. */
    mkldnn_primitive_kind_t primitive_kind;
    /** The kind of propagation. Possible values: #mkldnn_forward_training,
     * #mkldnn_forward_inference, #mkldnn_backward, and #mkldnn_backward_data.
     */
    mkldnn_prop_kind_t prop_kind;
    /** LRN algorithm. Possible values #mkldnn_lrn_within_channel or
     * #mkldnn_lrn_across_channels. */
    mkldnn_alg_kind_t alg_kind;
    /** Source and destination memory descriptor. */
    mkldnn_memory_desc_t data_desc;
    /** Source and destination gradient memory descriptor. */
    mkldnn_memory_desc_t diff_data_desc;
    /** The number of channels to sum over (for cross-channel LRN) or the side
     * length of the square region to sum over (for within-channel LRN). */
    int local_size;
    /** LRN alpha parameter. */
    float lrn_alpha;
    /** LRN beta parameter. */
    float lrn_beta;
    /** LRN k parameter. */
    float lrn_k;
} mkldnn_lrn_desc_t;

/** A descriptor of a Batch Normalization operation. */
typedef struct {
    /** The kind of primitive. Used for self identifying the primitive
     * descriptor. Must be #mkldnn_batch_normalization. */
    mkldnn_primitive_kind_t primitive_kind;
    /** The kind of propagation. Possible values: #mkldnn_forward_training,
     * #mkldnn_forward_inference, #mkldnn_backward, and #mkldnn_backward_data.
     */
    mkldnn_prop_kind_t prop_kind;
    /** Source and destination memory descriptor. */
    mkldnn_memory_desc_t data_desc;
    /** Source and destination gradient memory descriptor. */
    mkldnn_memory_desc_t diff_data_desc;
    /** Scale and shift data and gradient memory descriptors.
     *
     * Scaleshift memory descriptor uses 2D #mkldnn_nc format[2,Channels]. 1-st
     * dimension contains gamma parameter, 2-nd dimension contains beta
     * parameter. */
    mkldnn_memory_desc_t data_scaleshift_desc;
    mkldnn_memory_desc_t diff_data_scaleshift_desc;
    /** Mean and variance data memory descriptors.
     *
     * Mean and variance memory descriptors use 1D #mkldnn_x format[Channels].
     */
    mkldnn_memory_desc_t mean_desc;
    mkldnn_memory_desc_t variance_desc;
    /** Batch normalization epsilon parameter. */
    float batch_norm_epsilon;
    unsigned flags;
} mkldnn_batch_normalization_desc_t;

/** A descriptor of an inner product operation. */
typedef struct {
    /** The kind of primitive. Used for self identifying the primitive
     * descriptor. Must be #mkldnn_inner_product. */
    mkldnn_primitive_kind_t primitive_kind;
    /** The kind of propagation. Possible values: #mkldnn_forward_training,
     * #mkldnn_forward_inference, #mkldnn_backward_data,
     * #mkldnn_backward_weights, and #mkldnn_backward_bias. */
    mkldnn_prop_kind_t prop_kind;
    /** Source memory descriptor. */
    mkldnn_memory_desc_t src_desc;
    /** Source gradient memory descriptor. */
    mkldnn_memory_desc_t diff_src_desc;
    /** Weights memory descriptor. */
    mkldnn_memory_desc_t weights_desc;
    /** Weights gradient memory descriptor. */
    mkldnn_memory_desc_t diff_weights_desc;
    /** Bias memory descriptor. */
    mkldnn_memory_desc_t bias_desc;
    /** Bias gradient memory descriptor. */
    mkldnn_memory_desc_t diff_bias_desc;
    /** Destination memory descriptor. */
    mkldnn_memory_desc_t dst_desc;
    /** Destination gradient memory descriptor. */
    mkldnn_memory_desc_t diff_dst_desc;
    /** The accumulator data type. Initialized automatically. */
    mkldnn_data_type_t accum_data_type;
} mkldnn_inner_product_desc_t;

/** A descriptor of a convolution followed by relu operation. */
typedef struct {
    /** The kind of primitive. Used for self identifying the primitive
     * descriptor. Must be #mkldnn_convolution_relu. */
    mkldnn_primitive_kind_t primitive_kind;
    /** A descriptor of a convolution operation. */
    mkldnn_convolution_desc_t convolution_desc;
    /** Scaling factor for negative values, stored as float-precision but
     * interpreted in a way specific to the data type in each implementation */
    float negative_slope;
} mkldnn_convolution_relu_desc_t;

/** Flags for RNN cell. */
typedef enum {
    mkldnn_rnn_cell_with_relu = 0x1U,
    mkldnn_rnn_cell_with_clipping = 0x2U,
} mkldnn_rnn_cell_flags_t;

typedef struct {
    /** RNN cell kind. Must be one of #mkldnn_vanilla_rnn,
     * #mkldnn_vanilla_lstm, #mkldnn_vanilla_gru
     * or #mkldnn_gru_linear_before_reset. */
    mkldnn_alg_kind_t cell_kind;
    /** Activation function used. Must be one of #mkldnn_eltwise_relu,
     * #mkldnn_eltwise_tanh. */
    mkldnn_alg_kind_t activation_kind;
    /** RNN cell flags */
    unsigned int flags;
    /** alpha is a negative slope parameter (used only if
     * (flags & #mkldnn_rnn_cell_with_relu) != 0) */
    float alpha;
    /** clipping parameter (used only if
     * (flags & #mkldnn_rnn_cell_with_clipping) != 0) */
    float clipping;
} mkldnn_rnn_cell_desc_t;

/** A direction of RNN primitive execution */
typedef enum {
    /* Unidirectional execution of RNN primitive from left to right. */
    mkldnn_unidirectional_left2right,
    /* Unidirectional execution of RNN primitive from right to left. */
    mkldnn_unidirectional_right2left,
    /* Bidirectional execution of RNN primitive with concatenation of the
     * results. */
    mkldnn_bidirectional_concat,
    /* Bidirectional execution of RNN primitive with summation of the
     * results. */
    mkldnn_bidirectional_sum,
    mkldnn_unidirectional = mkldnn_unidirectional_left2right,
} mkldnn_rnn_direction_t;

/** A descriptor for an rnn operation */
typedef struct {
    /** The kind of primitive. Used for self identifying the primitive
     * descriptor. Must be #mkldnn_rnn. */
    mkldnn_primitive_kind_t primitive_kind;
    /** The kind of propagation. Possible values: #mkldnn_forward_training,
     * #mkldnn_forward_inference, #mkldnn_backward. */
    mkldnn_prop_kind_t prop_kind;
    /** The RNN cell desc. */
    mkldnn_rnn_cell_desc_t cell_desc;
    /** The direction of RNN primitive execution. */
    mkldnn_rnn_direction_t direction;
    /** Source layer memory descriptor. */
    mkldnn_memory_desc_t src_layer_desc;
    /** Source iteration memory descriptor. */
    mkldnn_memory_desc_t src_iter_desc;
    /** Weights layer memory descriptor. */
    mkldnn_memory_desc_t weights_layer_desc;
    /** Weights iteration memory descriptor. */
    mkldnn_memory_desc_t weights_iter_desc;
    /** Bias memory descriptor. */
    mkldnn_memory_desc_t bias_desc;
    /** Destination layer memory descriptor. */
    mkldnn_memory_desc_t dst_layer_desc;
    /** Destination iter memory descriptor. */
    mkldnn_memory_desc_t dst_iter_desc;
    /** Source gradient layer memory descriptor. */
    mkldnn_memory_desc_t diff_src_layer_desc;
    /** Source gradient iter memory descriptor. */
    mkldnn_memory_desc_t diff_src_iter_desc;
    /** Weights gradient layer memory descriptor. */
    mkldnn_memory_desc_t diff_weights_layer_desc;
    /** Weights gradient iter memory descriptor. */
    mkldnn_memory_desc_t diff_weights_iter_desc;
    /** Bias gradient memory descriptor. */
    mkldnn_memory_desc_t diff_bias_desc;
    /** Destination gradient layer memory descriptor. */
    mkldnn_memory_desc_t diff_dst_layer_desc;
    /** Destination gradient iteration memory descriptor. */
    mkldnn_memory_desc_t diff_dst_iter_desc;
} mkldnn_rnn_desc_t;

/** A descriptor of a ROI Pooling operation. */
typedef struct {
    /** The kind of primitive. Used for self identifying the primitive
     * descriptor. Must be #mkldnn_roi_pooling. */
    mkldnn_primitive_kind_t primitive_kind;
    /** The kind of propagation. Possible values: #mkldnn_forward. */
    mkldnn_prop_kind_t prop_kind;
    /** Source memory descriptor. */
    mkldnn_memory_desc_t* src_desc;
    /** Destination memory descriptor. */
    mkldnn_memory_desc_t dst_desc;

    /** Primitive parameters. */
    int pooled_h;
    int pooled_w;
    double spatial_scale;
    int num_src;
    mkldnn_alg_kind_t alg_kind;
} mkldnn_roi_pooling_desc_t;

/** @} */

/** @addtogroup c_api_engine_types Engine
 * @{ */

/** @brief Kinds of engines. */
typedef enum {
    /** An unspecified engine. */
    mkldnn_any_engine,
    /** CPU engine. */
    mkldnn_cpu,
} mkldnn_engine_kind_t;

/** @struct mkldnn_engine
 * @brief An opaque structure to describe an engine. */
struct mkldnn_engine;
/** @brief An engine handle. */
typedef struct mkldnn_engine *mkldnn_engine_t;
#if 0
/* FIXME: looks like this never happens */
/** @brief A constant engine handle. */
typedef const struct mkldnn_engine *const_mkldnn_engine_t;
#endif

/** @} */

/** @addtogroup c_api_primitive_desc_iterators Primitive descriptor iterators
 * @{ */

/** @struct mkldnn_primitive_desc_iterator
 * @brief An opaque structure to describe a primitive descriptor iterator . */
struct mkldnn_primitive_desc_iterator;

/** @brief A primitive descriptor iterator handle. */
typedef struct mkldnn_primitive_desc_iterator
    *mkldnn_primitive_desc_iterator_t;

/** @brief A constant primitive descriptor iterator handle. */
typedef const struct mkldnn_primitive_desc_iterator
    *const_mkldnn_primitive_desc_iterator_t;

/** @} */

/** @addtogroup c_api_primitive_descs Primitive descriptors
 * @{ */

/** @struct mkldnn_primitive_desc
 * @brief An opaque structure to describe a primitive descriptor . */
struct mkldnn_primitive_desc;

/** @brief A primitive descriptor handle. */
typedef struct mkldnn_primitive_desc *mkldnn_primitive_desc_t;

/** @brief A constant primitive descriptor handle. */
typedef const struct mkldnn_primitive_desc *const_mkldnn_primitive_desc_t;

/** @} */

/** @addtogroup c_api_primitive_attr Primitive descriptor attributes
 * @{ */

/** @struct mkldnn_primitive_attr
 * @brief An opaque structure for primitive descriptor attributes.
 *
 * Attributes may contain:
 *  - rounding mode for integer based primitives (like convolution, reorders)
 *  - output scales (to scale the result prior to storing it to the memory)
 */
struct mkldnn_primitive_attr;

/** @brief A primitive descriptor attributes handle that controls primitive
 * behavior. */
typedef struct mkldnn_primitive_attr *mkldnn_primitive_attr_t;

/** @brief A constant primitive descriptor attributes handle. */
typedef const struct mkldnn_primitive_attr *const_mkldnn_primitive_attr_t;

/** @struct mkldnn_post_ops
 * @brief An opaque structure for a chain of post operations.
 *
 * mkldnn_post_ops can be used to perform some (trivial) operations like
 * accumulation or eltwise after certain primitives like convolution.
 *
 * Post operations might be combined together, making a chain of post
 * operations. For instance one can configure convolution followed by
 * accumulation followed by eltwise (relu). This might be especially beneficial
 * for residual learning blocks.
 *
 * @warning
 *      Of course not all the combinations are supported, so user should handle
 *      error accordingly.
 *
 * Supported post operations:
 *  - accumulation (base primitive: convolution)
 *  - eltwise (base primitive: convolution)
 */
struct mkldnn_post_ops;

/** @brief A post operation chain handle. */
typedef struct mkldnn_post_ops *mkldnn_post_ops_t;

/** @brief A constant post operation chain handle. */
typedef const struct mkldnn_post_ops *const_mkldnn_post_ops_t;

/** @} */

/** @addtogroup c_api_types_primitive Primitive
 * @{ */

/** @struct mkldnn_primitive
 * An opaque structure to describe a primitive. */
struct mkldnn_primitive;
/** A primitive handle. */
typedef struct mkldnn_primitive *mkldnn_primitive_t;
/** A constant primitive handle. */
typedef const struct mkldnn_primitive *const_mkldnn_primitive_t;

/** A wrapper structure to specify a particular output of a primitive. */
typedef struct {
    /** Primitive to specify the output for. */
    const_mkldnn_primitive_t primitive;
    /** Desired output index. */
    size_t output_index;
} mkldnn_primitive_at_t;

/** @} */

/** @addtogroup c_api_types_query Queries
 * @{ */

/** Primitive descriptor query specification
 *
 * For generic function mkldnn_primitive_desc_query() the type of result must
 * be agreed with queried argument. The correspondence table:
 *      Query                        | type of result
 *      --------------------------------------------------------------
 *      #mkldnn_query_engine         | mkldnn_engine_t *
 *      #mkldnn_query_primitive_kind | mkldnn_primitive_kind_t *
 *      *_s32                        | int *
 *      *_s64                        | ptrdiff_t *
 *      *_f64                        | double *
 *      *_str                        | const char **
 *      *_md                         | const mkldnn_memory_desc_t **
 *      *_${op}_d                    | const mkldnn_${op}_desc_t **
 *      *_pd                         | const_mkldnn_primitive_desc_t *
 *
 * @note
 *     Rule of thumb: all opaque types and structures are returned by
 *     reference. All numbers are returned by value.
 *
 * @warning
 *     All returned references point to constant objects and valid only during
 *     the lifetime of queried primitive descriptor. Returned objects must not
 *     be destroyed by user. If there is a need to keep the object longer than
 *     a lifetime of queried primitive descriptor use
 *     mkldnn_primitive_desc_clone() to make a copy. */
typedef enum {
    mkldnn_query_undef = 0,  /**< no query */

    mkldnn_query_engine, /**< execution engine */
    mkldnn_query_primitive_kind, /**< primitive kind */

    mkldnn_query_num_of_inputs_s32, /**< number of inputs expected */
    mkldnn_query_num_of_outputs_s32, /**< number of outputs expected */

    mkldnn_query_time_estimate_f64, /**< runtime estimation (seconds) */
    mkldnn_query_memory_consumption_s64, /**< memory consumption -- extra
                                           (scratch) memory, additional to all
                                           inputs and outputs memory (bytes) */

    mkldnn_query_impl_info_str, /**< implementation name */

    /* memory and op descriptor section */
    mkldnn_query_some_d = 64, /**< stub */
    mkldnn_query_memory_d, /**< memory descriptor for memory and view */
    mkldnn_query_convolution_d, /**< convolution descriptor */
    mkldnn_query_deconvolution_d, /**< deconvolution descriptor */
    mkldnn_query_eltwise_d, /**< eltwise descriptor */
    mkldnn_query_relu_d = mkldnn_query_eltwise_d, /**< @deprecated */
    mkldnn_query_softmax_d, /**< softmax descriptor */
    mkldnn_query_pooling_d, /**< pooling descriptor */
    mkldnn_query_lrn_d, /**< lrn descriptor */
    mkldnn_query_batch_normalization_d, /**< batch normalization descriptor */
    mkldnn_query_inner_product_d, /**< inner product descriptor */
    mkldnn_query_convolution_relu_d, /**< @deprecated */
    mkldnn_query_rnn_d, /**< rnn descriptor */
    mkldnn_query_roi_pooling_d, /**< roi descriptor */
    mkldnn_query_depthwise_d, /**< eltwise descriptor */

    /* (memory) primitive descriptor section */
    mkldnn_query_some_pd = 128, /**< stub */
    mkldnn_query_input_pd, /**< input memory primitive desc */
    mkldnn_query_output_pd, /**< output memory primitive desc */
    mkldnn_query_src_pd, /**< source memory primitive desc */
    mkldnn_query_diff_src_pd, /**< source gradient memory primitive desc */
    mkldnn_query_weights_pd, /**< weights memory primitive descriptor desc */
    mkldnn_query_diff_weights_pd, /**< weights grad. memory primitive desc */
    mkldnn_query_dst_pd, /**< destination memory primitive desc */
    mkldnn_query_diff_dst_pd, /**< destination grad. memory primitive desc */
    mkldnn_query_workspace_pd, /**< workspace memory primitive desc */
} mkldnn_query_t;

/** @} */

/** @addtogroup c_api_types_stream Execution stream
 * @{ */

/** @brief Kinds of streams. */
typedef enum {
    /** An unspecified engine. */
    mkldnn_any_stream,
    /** Eager stream. */
    mkldnn_eager,
    /** Lazy stream. */
    mkldnn_lazy,
} mkldnn_stream_kind_t;

/** @struct mkldnn_stream
 * An opaque structure to describe an execution stream. */
struct mkldnn_stream;
/** An execution stream handle. */
typedef struct mkldnn_stream *mkldnn_stream_t;
/** A constant execution stream handle. */
typedef const struct mkldnn_stream *const_mkldnn_stream_t;

/** @} */
/** @} */
/** @} */

#ifdef __cplusplus
}
#endif


#endif
