API Reference

Abstract

This is the API Reference documentation for the cuDNN library. This API Reference consists of the cuDNN datatype reference chapter which describes the types of enums and the cuDNN API reference chapter which describes all routines in the cuDNN library API. The cuDNN API is a context-based API that allows for easy multithreading and (optional) interoperability with CUDA streams.

For previously released cuDNN developer documentation, see cuDNN Archives.

NVIDIA^® CUDA^® Deep Neural Network library™ (cuDNN) offers a context-based API that allows for easy multithreading and (optional) interoperability with NVIDIA^® CUDA^® streams. The cuDNN Datatypes Reference API describes all the types and enums of the cuDNN library API. The cuDNN API Reference describes the API of all the routines in the cuDNN library. The cuDNN library as well as this API document has been split into the following libraries:

• cudnn_ops_infer - This entity contains the routines related to cuDNN context creation and destruction, tensor descriptor management, tensor utility routines, and the inference portion of common ML algorithms such as batch normalization, softmax, dropout, etc.
• cudnn_ops_train - This entity contains common training routines and algorithms, such as batch normalization, softmax, dropout, etc. The cudnn_ops_train library depends on cudnn_ops_infer.
• cudnn_cnn_infer - This entity contains all routines related to convolutional neural networks needed at inference time. The cudnn_cnn_infer library depends on cudnn_ops_infer.
• cudnn_cnn_train - This entity contains all routines related to convolutional neural networks needed during training time. The cudnn_cnn_train library depends on cudnn_ops_infer, cudnn_ops_train, and cudnn_cnn_infer.
• cudnn_adv_infer - This entity contains all other features and algorithms. This includes RNNs, CTC loss, and Multihead Attention. The cudnn_adv_infer library depends on cudnn_ops_infer.
• cudnn_adv_train - This entity contains all the training counterparts of cudnn_adv_infer. The cudnn_adv_train library depends on cudnn_ops_infer, cudnn_ops_train, and cudnn_adv_infer.
• cudnn - This is an optional shim layer between the application layer and the cuDNN code. This layer opportunistically opens the correct library for the API at runtime.

2.1. API Changes For cuDNN 8.0.3

The following tables show which API functions were added, deprecated, and removed for the cuDNN 8.0.3.

2.2. API Changes For cuDNN 8.0.2

The following tables show which API functions were added, deprecated, and removed for the cuDNN 8.0.2.

2.3. API Changes For cuDNN 8.0.0 Preview

The following tables show which API functions were added, deprecated, and removed for the cuDNN 8.0.0 Preview Release.

For our deprecation policy, refer to the Backward Compatibility And Deprecation Policy section in the cuDNN Developer Guide.

3.1. Data Type References

3.1.1. Pointer To Opaque Struct Types

3.1.1.1. cudnnActivationDescriptor_t

cudnnActivationDescriptor_t is a pointer to an opaque structure holding the description of an activation operation. cudnnCreateActivationDescriptor() is used to create one instance, and cudnnSetActivationDescriptor() must be used to initialize this instance.

3.1.1.2. cudnnCTCLossDescriptor_t

cudnnCTCLossDescriptor_t is a pointer to an opaque structure holding the description of a CTC loss operation. cudnnCreateCTCLossDescriptor() is used to create one instance, cudnnSetCTCLossDescriptor() is used to initialize this instance, and cudnnDestroyCTCLossDescriptor() is used to destroy this instance.

3.1.1.3. cudnnDropoutDescriptor_t

cudnnDropoutDescriptor_t is a pointer to an opaque structure holding the description of a dropout operation. cudnnCreateDropoutDescriptor() is used to create one instance, cudnnSetDropoutDescriptor() is used to initialize this instance, cudnnDestroyDropoutDescriptor() is used to destroy this instance, cudnnGetDropoutDescriptor() is used to query fields of a previously initialized instance, cudnnRestoreDropoutDescriptor() is used to restore an instance to a previously saved off state.

3.1.1.4. cudnnFilterDescriptor_t

cudnnFilterDescriptor_t is a pointer to an opaque structure holding the description of a filter dataset. cudnnCreateFilterDescriptor() is used to create one instance, and cudnnSetFilter4dDescriptor() or cudnnSetFilterNdDescriptor() must be used to initialize this instance.

3.1.1.5. cudnnHandle_t

cudnnHandle_t is a pointer to an opaque structure holding the cuDNN library context. The cuDNN library context must be created using cudnnCreate() and the returned handle must be passed to all subsequent library function calls. The context should be destroyed at the end using cudnnDestroy(). The context is associated with only one GPU device, the current device at the time of the call to cudnnCreate(). However, multiple contexts can be created on the same GPU device.

3.1.1.6. cudnnLRNDescriptor_t

cudnnLRNDescriptor_t is a pointer to an opaque structure holding the parameters of a local response normalization. cudnnCreateLRNDescriptor() is used to create one instance, and the routine cudnnSetLRNDescriptor() must be used to initialize this instance.

3.1.1.7. cudnnOpTensorDescriptor_t

cudnnOpTensorDescriptor_t is a pointer to an opaque structure holding the description of a Tensor Core operation, used as a parameter to cudnnOpTensor(). cudnnCreateOpTensorDescriptor() is used to create one instance, and cudnnSetOpTensorDescriptor() must be used to initialize this instance.

3.1.1.8. cudnnPoolingDescriptor_t

cudnnPoolingDescriptor_t is a pointer to an opaque structure holding the description of a pooling operation. cudnnCreatePoolingDescriptor() is used to create one instance, and cudnnSetPoolingNdDescriptor() or cudnnSetPooling2dDescriptor() must be used to initialize this instance.

3.1.1.9. cudnnReduceTensorDescriptor_t

cudnnReduceTensorDescriptor_t is a pointer to an opaque structure holding the description of a tensor reduction operation, used as a parameter to cudnnReduceTensor(). cudnnCreateReduceTensorDescriptor() is used to create one instance, and cudnnSetReduceTensorDescriptor() must be used to initialize this instance.

3.1.1.10. cudnnSpatialTransformerDescriptor_t

cudnnSpatialTransformerDescriptor_t is a pointer to an opaque structure holding the description of a spatial transformation operation. cudnnCreateSpatialTransformerDescriptor() is used to create one instance, cudnnSetSpatialTransformerNdDescriptor() is used to initialize this instance, and cudnnDestroySpatialTransformerDescriptor() is used to destroy this instance.

3.1.1.11. cudnnTensorDescriptor_t

cudnnCreateTensorDescriptor_t is a pointer to an opaque structure holding the description of a generic n-D dataset. cudnnCreateTensorDescriptor() is used to create one instance, and one of the routines cudnnSetTensorNdDescriptor(), cudnnSetTensor4dDescriptor() or cudnnSetTensor4dDescriptorEx() must be used to initialize this instance.

3.1.1.12. cudnnTensorTransformDescriptor_t

cudnnTensorTransformDescriptor_t is an opaque structure containing the description of the tensor transform. Use the cudnnCreateTensorTransformDescriptor() function to create an instance of this descriptor, and cudnnDestroyTensorTransformDescriptor() function to destroy a previously created instance.

3.1.2. Enumeration Types

3.1.2.1. cudnnActivationMode_t

cudnnActivationMode_t is an enumerated type used to select the neuron activation function used in cudnnActivationForward(), cudnnActivationBackward(), and cudnnConvolutionBiasActivationForward().

Values

CUDNN_ACTIVATION_SIGMOID

Selects the sigmoid function.

CUDNN_ACTIVATION_RELU

Selects the rectified linear function.

CUDNN_ACTIVATION_TANH

Selects the hyperbolic tangent function.

CUDNN_ACTIVATION_CLIPPED_RELU

Selects the clipped rectified linear function.

CUDNN_ACTIVATION_ELU

Selects the exponential linear function.

CUDNN_ACTIVATION_IDENTITY

Selects the identity function, intended for bypassing the activation step in cudnnConvolutionBiasActivationForward(). (The cudnnConvolutionBiasActivationForward() function must use CUDNN_CONVOLUTION_FWD_ALGO_IMPLICIT_PRECOMP_GEMM.) Does not work with cudnnActivationForward() or cudnnActivationBackward().

3.1.2.2. cudnnAlgorithm_t

This function has been deprecated in cuDNN 8.0.

3.1.2.3. cudnnBatchNormMode_t

cudnnBatchNormMode_t is an enumerated type used to specify the mode of operation in cudnnBatchNormalizationForwardInference(), cudnnBatchNormalizationForwardTraining(), cudnnBatchNormalizationBackward() and cudnnDeriveBNTensorDescriptor() routines.

Values

CUDNN_BATCHNORM_PER_ACTIVATION

Normalization is performed per-activation. This mode is intended to be used after the non-convolutional network layers. In this mode, the tensor dimensions of bnBias and bnScale and the parameters used in the cudnnBatchNormalization* functions, are 1xCxHxW.

CUDNN_BATCHNORM_SPATIAL

Normalization is performed over N+spatial dimensions. This mode is intended for use after convolutional layers (where spatial invariance is desired). In this mode the bnBias and bnScale tensor dimensions are 1xCx1x1.

CUDNN_BATCHNORM_SPATIAL_PERSISTENT

This mode is similar to CUDNN_BATCHNORM_SPATIAL but it can be faster for some tasks.

An optimized path may be selected for CUDNN_DATA_FLOAT and CUDNN_DATA_HALF types, compute capability 6.0 or higher for the following two batch normalization API calls: cudnnBatchNormalizationForwardTraining(), and cudnnBatchNormalizationBackward(). In the case of cudnnBatchNormalizationBackward(), the savedMean and savedInvVariance arguments should not be NULL.

The rest of this section applies to NCHW mode only:

This mode may use a scaled atomic integer reduction that is deterministic but imposes more restrictions on the input data range. When a numerical overflow occurs, the algorithm may produce NaN-s or Inf-s (infinity) in output buffers.

When Inf-s/NaN-s are present in the input data, the output in this mode is the same as from a pure floating-point implementation.

For finite but very large input values, the algorithm may encounter overflows more frequently due to a lower dynamic range and emit Inf-s/NaN-s while CUDNN_BATCHNORM_SPATIAL will produce finite results. The user can invoke cudnnQueryRuntimeError() to check if a numerical overflow occurred in this mode.

3.1.2.4. cudnnBatchNormOps_t

cudnnBatchNormOps_t is an enumerated type used to specify the mode of operation in cudnnGetBatchNormalizationForwardTrainingExWorkspaceSize(), cudnnBatchNormalizationForwardTrainingEx(), cudnnGetBatchNormalizationBackwardExWorkspaceSize(), cudnnBatchNormalizationBackwardEx(), and cudnnGetBatchNormalizationTrainingExReserveSpaceSize() functions.

Values

CUDNN_BATCHNORM_OPS_BN

Only batch normalization is performed, per-activation.

CUDNN_BATCHNORM_OPS_BN_ACTIVATION

First, the batch normalization is performed, and then the activation is performed.

CUDNN_BATCHNORM_OPS_BN_ADD_ACTIVATION

Performs the batch normalization, then element-wise addition, followed by the activation operation.

3.1.2.5. cudnnCTCLossAlgo_t

cudnnCTCLossAlgo_t is an enumerated type that exposes the different algorithms available to execute the CTC loss operation.

Values

CUDNN_CTC_LOSS_ALGO_DETERMINISTIC

Results are guaranteed to be reproducible.

CUDNN_CTC_LOSS_ALGO_NON_DETERMINISTIC

Results are not guaranteed to be reproducible.

3.1.2.6. cudnnDataType_t

cudnnDataType_t is an enumerated type indicating the data type to which a tensor descriptor or filter descriptor refers.

Values

CUDNN_DATA_FLOAT

The data is a 32-bit single-precision floating-point (float).

CUDNN_DATA_DOUBLE

The data is a 64-bit double-precision floating-point (double).

CUDNN_DATA_HALF

The data is a 16-bit floating-point.

CUDNN_DATA_INT8

The data is an 8-bit signed integer.

CUDNN_DATA_UINT8

The data is an 8-bit unsigned integer.

CUDNN_DATA_INT32

The data is a 32-bit signed integer.

CUDNN_DATA_INT8x4

The data is 32-bit elements each composed of 4 8-bit signed integers. This data type is only supported with tensor format CUDNN_TENSOR_NCHW_VECT_C.

CUDNN_DATA_INT8x32

The data is 32-element vectors, each element being an 8-bit signed integer. This data type is only supported with the tensor format CUDNN_TENSOR_NCHW_VECT_C. Moreover, this data type can only be used with algo 1, meaning, CUDNN_CONVOLUTION_FWD_ALGO_IMPLICIT_PRECOMP_GEMM. For more information, see cudnnConvolutionFwdAlgo_t.

CUDNN_DATA_UINT8x4

The data is 32-bit elements each composed of 4 8-bit unsigned integers. This data type is only supported with tensor format CUDNN_TENSOR_NCHW_VECT_C.

3.1.2.7. cudnnDeterminism_t

cudnnDeterminism_t is an enumerated type used to indicate if the computed results are deterministic (reproducible). For more information, see Reproducibility (determinism).

Values

CUDNN_NON_DETERMINISTIC

Results are not guaranteed to be reproducible.

CUDNN_DETERMINISTIC

Results are guaranteed to be reproducible.

3.1.2.8. cudnnDivNormMode_t

cudnnDivNormMode_t is an enumerated type used to specify the mode of operation in cudnnDivisiveNormalizationForward() and cudnnDivisiveNormalizationBackward().

Values

CUDNN_DIVNORM_PRECOMPUTED_MEANS

The means tensor data pointer is expected to contain means or other kernel convolution values precomputed by the user. The means pointer can also be NULL, in that case, it's considered to be filled with zeroes. This is equivalent to spatial LRN.

Note:

In the backward pass, the means are treated as independent inputs and the gradient over means is computed independently. In this mode, to yield a net gradient over the entire LCN computational graph, the destDiffMeans result should be backpropagated through the user's means layer (which can be implemented using average pooling) and added to the destDiffData tensor produced by cudnnDivisiveNormalizationBackward().

3.1.2.9. cudnnErrQueryMode_t

cudnnErrQueryMode_t is an enumerated type passed to cudnnQueryRuntimeError() to select the remote kernel error query mode.

Values

CUDNN_ERRQUERY_RAWCODE

Read the error storage location regardless of the kernel completion status.

CUDNN_ERRQUERY_NONBLOCKING

Report if all tasks in the user stream of the cuDNN handle were completed. If that is the case, report the remote kernel error code.

CUDNN_ERRQUERY_BLOCKING

Wait for all tasks to complete in the user stream before reporting the remote kernel error code.

3.1.2.10. cudnnFoldingDirection_t

cudnnFoldingDirection_t is an enumerated type used to select the folding direction. For more information, see cudnnTensorTransformDescriptor_t.

Data Member

CUDNN_TRANSFORM_FOLD = 0U

Selects folding.

CUDNN_TRANSFORM_UNFOLD = 1U

Selects unfolding.

3.1.2.11. cudnnIndicesType_t

cudnnIndicesType_t is an enumerated type used to indicate the data type for the indices to be computed by the cudnnReduceTensor() routine. This enumerated type is used as a field for the cudnnReduceTensorDescriptor_t descriptor.

Values

CUDNN_32BIT_INDICES

Compute unsigned int indices.

CUDNN_64BIT_INDICES

Compute unsigned long indices.

CUDNN_16BIT_INDICES

Compute unsigned short indices.

CUDNN_8BIT_INDICES

Compute unsigned char indices.

3.1.2.12. cudnnLRNMode_t

cudnnLRNMode_t is an enumerated type used to specify the mode of operation in cudnnLRNCrossChannelForward() and cudnnLRNCrossChannelBackward().

Values

CUDNN_LRN_CROSS_CHANNEL_DIM1

LRN computation is performed across tensor's dimension dimA[1].

3.1.2.13. cudnnMathType_t

cudnnMathType_t is an enumerated type used to indicate if the use of Tensor Core operations is permitted in a given library routine.

Values

CUDNN_DEFAULT_MATH

Tensor Core operations are not used on pre-NVIDIA A100 GPU devices. On A100 GPU architecture devices, Tensor Core TF32 operation is permitted.

CUDNN_TENSOR_OP_MATH

The use of Tensor Core operations is permitted but will not actively perform datatype down conversion on tensors in order to utilize Tensor Cores.

CUDNN_TENSOR_OP_MATH_ALLOW_CONVERSION

The use of Tensor Core operations is permitted and will actively perform datatype down conversion on tensors in order to utilize Tensor Cores.

CUDNN_FMA_MATH

Restricted to only kernels that use FMA instructions.

On pre-NVIDIA A100 GPU devices, CUDNN_DEFAULT_MATH and CUDNN_FMA_MATH have the same behavior: Tensor Core kernels will not be selected. With NVIDIA Ampere GPU architecture and CUDA Toolkit 11, CUDNN_DEFAULT_MATH permits TF32 Tensor Core operation and CUDNN_FMA_MATH does not. The TF32 behavior for CUDNN_DEFAULT_MATH can be explicitly disabled by the environment variable NVIDIA_TF32_OVERRIDE=0.

3.1.2.14. cudnnNanPropagation_t

cudnnNanPropagation_t is an enumerated type used to indicate if a given routine should propagate Nan numbers. This enumerated type is used as a field for the cudnnActivationDescriptor_t descriptor and cudnnPoolingDescriptor_t descriptor.

Values

CUDNN_NOT_PROPAGATE_NAN

Nan numbers are not propagated.

CUDNN_PROPAGATE_NAN

Nan numbers are propagated.

3.1.2.15. cudnnNormAlgo_t

cudnnNormAlgo_t is an enumerated type used to specify the algorithm to execute the normalization operation.

Values

CUDNN_NORM_ALGO_STANDARD

Standard normalization is performed.

CUDNN_NORM_ALGO_PERSIST

This mode is similar to CUDNN_NORM_ALGO_STANDARD, however it only supports CUDNN_NORM_PER_CHANNEL and can be faster for some tasks.

An optimized path may be selected for CUDNN_DATA_FLOAT and CUDNN_DATA_HALF types, compute capability 6.0 or higher for the following two normalization API calls: cudnnNormalizationForwardTraining() and cudnnNormalizationBackward(). In the case of cudnnNormalizationBackward(), the savedMean and savedInvVariance arguments should not be NULL.

The rest of this section applies to NCHW mode only: This mode may use a scaled atomic integer reduction that is deterministic but imposes more restrictions on the input data range. When a numerical overflow occurs, the algorithm may produce NaN-s or Inf-s (infinity) in output buffers.

When Inf-s/NaN-s are present in the input data, the output in this mode is the same as from a pure floating-point implementation.

For finite but very large input values, the algorithm may encounter overflows more frequently due to a lower dynamic range and emit Inf-s/NaN-s while CUDNN_NORM_ALGO_STANDARD will produce finite results. The user can invoke cudnnQueryRuntimeError() to check if a numerical overflow occurred in this mode.

3.1.2.16. cudnnNormMode_t

cudnnNormMode_t is an enumerated type used to specify the mode of operation in cudnnNormalizationForwardInference(), cudnnNormalizationForwardTraining(), cudnnBatchNormalizationBackward(), cudnnGetNormalizationForwardTrainingWorkspaceSize(), cudnnGetNormalizationBackwardWorkspaceSize(), and cudnnGetNormalizationTrainingReserveSpaceSize() routines.

Values

CUDNN_NORM_PER_ACTIVATION

Normalization is performed per-activation. This mode is intended to be used after the non-convolutional network layers. In this mode, the tensor dimensions of normBias and normScale and the parameters used in the cudnnNormalization* functions, are 1xCxHxW.

CUDNN_NORM_PER_CHANNEL

Normalization is performed per-channel over N+spatial dimensions. This mode is intended for use after convolutional layers (where spatial invariance is desired). In this mode, the normBias and normScale tensor dimensions are 1xCx1x1.

3.1.2.17. cudnnNormOps_t

cudnnNormOps_t is an enumerated type used to specify the mode of operation in cudnnGetNormalizationForwardTrainingWorkspaceSize(), cudnnNormalizationForwardTraining(), cudnnGetNormalizationBackwardWorkspaceSize(), cudnnNormalizationBackward(), and cudnnGetNormalizationTrainingReserveSpaceSize() functions.

Values

CUDNN_NORM_OPS_NORM

Only normalization is performed.

CUDNN_NORM_OPS_NORM_ACTIVATION

First, the normalization is performed, then the activation is performed.

CUDNN_NORM_OPS_NORM_ADD_ACTIVATION

Performs the normalization, then element-wise addition, followed by the activation operation.

3.1.2.18. cudnnOpTensorOp_t

cudnnOpTensorOp_t is an enumerated type used to indicate the Tensor Core operation to be used by the cudnnOpTensor() routine. This enumerated type is used as a field for the cudnnOpTensorDescriptor_t descriptor.

Values

CUDNN_OP_TENSOR_ADD

The operation to be performed is addition.

CUDNN_OP_TENSOR_MUL

The operation to be performed is multiplication.

CUDNN_OP_TENSOR_MIN

The operation to be performed is a minimum comparison.

CUDNN_OP_TENSOR_MAX

The operation to be performed is a maximum comparison.

CUDNN_OP_TENSOR_SQRT

The operation to be performed is square root, performed on only the A tensor.

CUDNN_OP_TENSOR_NOT

The operation to be performed is negation, performed on only the A tensor.

3.1.2.19. cudnnPoolingMode_t

cudnnPoolingMode_t is an enumerated type passed to cudnnSetPooling2dDescriptor() to select the pooling method to be used by cudnnPoolingForward() and cudnnPoolingBackward().

Values

CUDNN_POOLING_MAX

The maximum value inside the pooling window is used.

CUDNN_POOLING_AVERAGE_COUNT_INCLUDE_PADDING

Values inside the pooling window are averaged. The number of elements used to calculate the average includes spatial locations falling in the padding region.

CUDNN_POOLING_AVERAGE_COUNT_EXCLUDE_PADDING

Values inside the pooling window are averaged. The number of elements used to calculate the average excludes spatial locations falling in the padding region.

CUDNN_POOLING_MAX_DETERMINISTIC

The maximum value inside the pooling window is used. The algorithm used is deterministic.

3.1.2.20. cudnnReduceTensorIndices_t

cudnnReduceTensorIndices_t is an enumerated type used to indicate whether indices are to be computed by the cudnnReduceTensor() routine. This enumerated type is used as a field for the cudnnReduceTensorDescriptor_t descriptor.

Values

CUDNN_REDUCE_TENSOR_NO_INDICES

Do not compute indices.

CUDNN_REDUCE_TENSOR_FLATTENED_INDICES

Compute indices. The resulting indices are relative, and flattened.

3.1.2.21. cudnnReduceTensorOp_t

cudnnReduceTensorOp_t is an enumerated type used to indicate the Tensor Core operation to be used by the cudnnReduceTensor() routine. This enumerated type is used as a field for the cudnnReduceTensorDescriptor_t descriptor.

Values

CUDNN_REDUCE_TENSOR_ADD

The operation to be performed is addition.

CUDNN_REDUCE_TENSOR_MUL

The operation to be performed is multiplication.

CUDNN_REDUCE_TENSOR_MIN

The operation to be performed is a minimum comparison.

CUDNN_REDUCE_TENSOR_MAX

The operation to be performed is a maximum comparison.

CUDNN_REDUCE_TENSOR_AMAX

The operation to be performed is a maximum comparison of absolute values.

CUDNN_REDUCE_TENSOR_AVG

The operation to be performed is averaging.

CUDNN_REDUCE_TENSOR_NORM1

The operation to be performed is addition of absolute values.

CUDNN_REDUCE_TENSOR_NORM2

The operation to be performed is a square root of the sum of squares.

CUDNN_REDUCE_TENSOR_MUL_NO_ZEROS

The operation to be performed is multiplication, not including elements of value zero.

3.1.2.22. cudnnRNNAlgo_t

cudnnRNNAlgo_t is an enumerated type used to specify the algorithm used in the cudnnRNNForwardInference(), cudnnRNNForwardTraining(), cudnnRNNBackwardData() and cudnnRNNBackwardWeights() routines.

Values

CUDNN_RNN_ALGO_STANDARD

Each RNN layer is executed as a sequence of operations. This algorithm is expected to have robust performance across a wide range of network parameters.

CUDNN_RNN_ALGO_PERSIST_STATIC

The recurrent parts of the network are executed using a persistent kernel approach. This method is expected to be fast when the first dimension of the input tensor is small (meaning, a small minibatch).

CUDNN_RNN_ALGO_PERSIST_STATIC is only supported on devices with compute capability >= 6.0.

CUDNN_RNN_ALGO_PERSIST_DYNAMIC

The recurrent parts of the network are executed using a persistent kernel approach. This method is expected to be fast when the first dimension of the input tensor is small (meaning, a small minibatch). When using CUDNN_RNN_ALGO_PERSIST_DYNAMIC persistent kernels are prepared at runtime and are able to optimize using the specific parameters of the network and active GPU. As such, when using CUDNN_RNN_ALGO_PERSIST_DYNAMIC a one-time plan preparation stage must be executed. These plans can then be reused in repeated calls with the same model parameters.

The limits on the maximum number of hidden units supported when using CUDNN_RNN_ALGO_PERSIST_DYNAMIC are significantly higher than the limits when using CUDNN_RNN_ALGO_PERSIST_STATIC, however throughput is likely to significantly reduce when exceeding the maximums supported by CUDNN_RNN_ALGO_PERSIST_STATIC. In this regime, this method will still outperform CUDNN_RNN_ALGO_STANDARD for some cases.

CUDNN_RNN_ALGO_PERSIST_DYNAMIC is only supported on devices with compute capability >= 6.0 on Linux machines.

3.1.2.23. cudnnSamplerType_t

cudnnSamplerType_t is an enumerated type passed to cudnnSetSpatialTransformerNdDescriptor() to select the sampler type to be used by cudnnSpatialTfSamplerForward() and cudnnSpatialTfSamplerBackward().

Values

CUDNN_SAMPLER_BILINEAR

Selects the bilinear sampler.

3.1.2.24. cudnnSeverity_t

cudnnSeverity_t is an enumerated type passed to the customized callback function for logging that users may set. This enumerate describes the severity level of the item, so the customized logging call back may react differently.

Values

CUDNN_SEV_FATAL

This value indicates a fatal error emitted by cuDNN.

CUDNN_SEV_ERROR

This value indicates a normal error emitted by cuDNN.

CUDNN_SEV_WARNING

This value indicates a warning emitted by cuDNN.

CUDNN_SEV_INFO

This value indicates a piece of information (for example, API log) emitted by cuDNN.

3.1.2.25. cudnnSoftmaxAlgorithm_t

cudnnSoftmaxAlgorithm_t is used to select an implementation of the softmax function used in cudnnSoftmaxForward() and cudnnSoftmaxBackward().

Values

CUDNN_SOFTMAX_FAST

This implementation applies the straightforward softmax operation.

CUDNN_SOFTMAX_ACCURATE

This implementation scales each point of the softmax input domain by its maximum value to avoid potential floating point overflows in the softmax evaluation.

CUDNN_SOFTMAX_LOG

This entry performs the log softmax operation, avoiding overflows by scaling each point in the input domain as in CUDNN_SOFTMAX_ACCURATE.

3.1.2.26. cudnnSoftmaxMode_t

cudnnSoftmaxMode_t is used to select over which data the cudnnSoftmaxForward() and cudnnSoftmaxBackward() are computing their results.

Values

CUDNN_SOFTMAX_MODE_INSTANCE

The softmax operation is computed per image (N) across the dimensions C,H,W.

CUDNN_SOFTMAX_MODE_CHANNEL

The softmax operation is computed per spatial location (H,W) per image (N) across the dimension C.

3.1.2.27. cudnnStatus_t

cudnnStatus_t is an enumerated type used for function status returns. All cuDNN library functions return their status, which can be one of the following values:

Values

CUDNN_STATUS_SUCCESS

The operation was completed successfully.

CUDNN_STATUS_NOT_INITIALIZED

The cuDNN library was not initialized properly. This error is usually returned when a call to cudnnCreate() fails or when cudnnCreate() has not been called prior to calling another cuDNN routine. In the former case, it is usually due to an error in the CUDA Runtime API called by cudnnCreate() or by an error in the hardware setup.

CUDNN_STATUS_ALLOC_FAILED

Resource allocation failed inside the cuDNN library. This is usually caused by an internal cudaMalloc() failure.

To correct, prior to the function call, deallocate previously allocated memory as much as possible.

CUDNN_STATUS_BAD_PARAM

An incorrect value or parameter was passed to the function.

To correct, ensure that all the parameters being passed have valid values.

CUDNN_STATUS_ARCH_MISMATCH

The function requires a feature absent from the current GPU device. Note that cuDNN only supports devices with compute capabilities greater than or equal to 3.0.

To correct, compile and run the application on a device with appropriate compute capability.

CUDNN_STATUS_MAPPING_ERROR

An access to GPU memory space failed, which is usually caused by a failure to bind a texture.

To correct, prior to the function call, unbind any previously bound textures.

Otherwise, this may indicate an internal error/bug in the library.

CUDNN_STATUS_EXECUTION_FAILED

The GPU program failed to execute. This is usually caused by a failure to launch some cuDNN kernel on the GPU, which can occur for multiple reasons.

To correct, check that the hardware, an appropriate version of the driver, and the cuDNN library are correctly installed.

Otherwise, this may indicate an internal error/bug in the library.

CUDNN_STATUS_INTERNAL_ERROR

An internal cuDNN operation failed.

CUDNN_STATUS_NOT_SUPPORTED

The functionality requested is not presently supported by cuDNN.

CUDNN_STATUS_LICENSE_ERROR

The functionality requested requires some license and an error was detected when trying to check the current licensing. This error can happen if the license is not present or is expired or if the environment variable NVIDIA_LICENSE_FILE is not set properly.

CUDNN_STATUS_RUNTIME_PREREQUISITE_MISSING

The runtime library that is required by RNN calls (libcuda.so or nvcuda.dll) cannot be found in predefined search paths.

CUDNN_STATUS_RUNTIME_IN_PROGRESS

Some tasks in the user stream are not completed.

CUDNN_STATUS_RUNTIME_FP_OVERFLOW

Numerical overflow occurred during the GPU kernel execution.

3.1.2.28. cudnnTensorFormat_t

cudnnTensorFormat_t is an enumerated type used by cudnnSetTensor4dDescriptor() to create a tensor with a pre-defined layout. For a detailed explanation of how these tensors are arranged in memory, see the Data Layout Formats section in the cuDNN Developer Guide.

Values

CUDNN_TENSOR_NCHW

This tensor format specifies that the data is laid out in the following order: batch size, feature maps, rows, columns. The strides are implicitly defined in such a way that the data are contiguous in memory with no padding between images, feature maps, rows, and columns; the columns are the inner dimension and the images are the outermost dimension.

CUDNN_TENSOR_NHWC

This tensor format specifies that the data is laid out in the following order: batch size, rows, columns, feature maps. The strides are implicitly defined in such a way that the data are contiguous in memory with no padding between images, rows, columns, and feature maps; the feature maps are the inner dimension and the images are the outermost dimension.

CUDNN_TENSOR_NCHW_VECT_C

This tensor format specifies that the data is laid out in the following order: batch size, feature maps, rows, columns. However, each element of the tensor is a vector of multiple feature maps. The length of the vector is carried by the data type of the tensor. The strides are implicitly defined in such a way that the data are contiguous in memory with no padding between images, feature maps, rows, and columns; the columns are the inner dimension and the images are the outermost dimension. This format is only supported with tensor data types CUDNN_DATA_INT8x4, CUDNN_DATA_INT8x32, and CUDNN_DATA_UINT8x4.

The CUDNN_TENSOR_NCHW_VECT_C can also be interpreted in the following way: The NCHW INT8x32 format is really N x (C/32) x H x W x 32 (32 Cs for every W), just as the NCHW INT8x4 format is N x (C/4) x H x W x 4 (4 Cs for every W). Hence, the VECT_C name - each W is a vector (4 or 32) of Cs.

3.2. API Functions

3.2.1. cudnnActivationForward()

            

            
cudnnStatus_t cudnnActivationForward(
    cudnnHandle_t handle,
    cudnnActivationDescriptor_t     activationDesc,
    const void                     *alpha,
    const cudnnTensorDescriptor_t   xDesc,
    const void                     *x,
    const void                     *beta,
    const cudnnTensorDescriptor_t   yDesc,
    void                           *y)
        

This routine applies a specified neuron activation function element-wise over each input value.

Parameters

handle

Input. Handle to a previously created cuDNN context. For more information, see cudnnHandle_t.

activationDesc

Input. Activation descriptor. For more information, see cudnnActivationDescriptor_t.

alpha, beta

Input. Pointers to scaling factors (in host memory) used to blend the computation result with prior value in the output layer as follows:

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dstValue = alpha[0]*result + beta[0]*priorDstValue
        

For more information, see Scaling Parameters in the cuDNN Developer Guide.

xDesc

Input. Handle to the previously initialized input tensor descriptor. For more information, see cudnnTensorDescriptor_t.

x

Input. Data pointer to GPU memory associated with the tensor descriptor xDesc.

yDesc

Input. Handle to the previously initialized output tensor descriptor.

y

Output. Data pointer to GPU memory associated with the output tensor descriptor yDesc.

Returns

CUDNN_STATUS_SUCCESS

The function launched successfully.

CUDNN_STATUS_NOT_SUPPORTED

The function does not support the provided configuration.

CUDNN_STATUS_BAD_PARAM

At least one of the following conditions are met:

• The parameter mode has an invalid enumerant value.
• The dimensions n, c, h, w of the input tensor and output tensor differ.
• The datatype of the input tensor and output tensor differs.
• The strides nStride, cStride, hStride, wStride of the input tensor and output tensor differ and in-place operation is used (meaning, x and y pointers are equal).

CUDNN_STATUS_EXECUTION_FAILED

The function failed to launch on the GPU.

3.2.2. cudnnAddTensor()

            

            
cudnnStatus_t cudnnAddTensor(
    cudnnHandle_t                     handle,
    const void                       *alpha,
    const cudnnTensorDescriptor_t     aDesc,
    const void                       *A,
    const void                       *beta,
    const cudnnTensorDescriptor_t     cDesc,
    void                             *C)
        

This function adds the scaled values of a bias tensor to another tensor. Each dimension of the bias tensor A must match the corresponding dimension of the destination tensor C or must be equal to 1. In the latter case, the same value from the bias tensor for those dimensions will be used to blend into the C tensor.

Parameters

handle

Input. Handle to a previously created cuDNN context. For more information, see cudnnHandle_t.

alpha, beta

Input. Pointers to scaling factors (in host memory) used to blend the source value with the prior value in the destination tensor as follows:

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dstValue = alpha[0]*srcValue + beta[0]*priorDstValue
        

For more information, see Scaling Parameters in the cuDNN Developer Guide.

aDesc

Input. Handle to a previously initialized tensor descriptor. For more information, see cudnnTensorDescriptor_t.

A

Input. Pointer to data of the tensor described by the aDesc descriptor.

cDesc

Input. Handle to a previously initialized tensor descriptor.

C

Input/Output. Pointer to data of the tensor described by the cDesc descriptor.

Returns

CUDNN_STATUS_SUCCESS

The function executed successfully.

CUDNN_STATUS_NOT_SUPPORTED

The function does not support the provided configuration.

CUDNN_STATUS_BAD_PARAM

The dimensions of the bias tensor refer to an amount of data that is incompatible with the output tensor dimensions or the dataType of the two tensor descriptors are different.

CUDNN_STATUS_EXECUTION_FAILED

The function failed to launch on the GPU.

3.2.3. cudnnBatchNormalizationForwardInference()

            

            
cudnnStatus_t cudnnBatchNormalizationForwardInference(
      cudnnHandle_t                    handle,
      cudnnBatchNormMode_t             mode,
      const void                      *alpha,
      const void                      *beta,
      const cudnnTensorDescriptor_t    xDesc,
      const void                      *x,
      const cudnnTensorDescriptor_t    yDesc,
      void                            *y,
      const cudnnTensorDescriptor_t    bnScaleBiasMeanVarDesc,
      const void                      *bnScale,
      const void                      *bnBias,
      const void                      *estimatedMean,
      const void                      *estimatedVariance,
      double                           epsilon)
        

This function performs the forward batch normalization layer computation for the inference phase. This layer is based on the paper Batch Normalization: Accelerating Deep Network Training by Reducing Internal Covariate Shift, S. Ioffe, C. Szegedy, 2015.

Parameters

handle

Input. Handle to a previously created cuDNN library descriptor. For more information, see cudnnHandle_t.

mode

Input. Mode of operation (spatial or per-activation). For more information, see cudnnBatchNormMode_t.

alpha, beta

Inputs. Pointers to scaling factors (in host memory) used to blend the layer output value with prior value in the destination tensor as follows:

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dstValue = alpha[0]*resultValue + beta[0]*priorDstValue
        

For more information, see Scaling Parameters in the cuDNN Developer Guide.

xDesc, yDesc

Input. Handles to the previously initialized tensor descriptors.

*x

Input. Data pointer to GPU memory associated with the tensor descriptor xDesc, for the layer’s x input data.

*y

Input. Data pointer to GPU memory associated with the tensor descriptor yDesc, for the youtput of the batch normalization layer.

bnScaleBiasMeanVarDesc, bnScale, bnBias

Inputs. Tensor descriptors and pointers in device memory for the batch normalization scale and bias parameters (in the original paper bias is referred to as beta and scale as gamma).

estimatedMean, estimatedVariance

Inputs. Mean and variance tensors (these have the same descriptor as the bias and scale). The resultRunningMean and resultRunningVariance, accumulated during the training phase from the cudnnBatchNormalizationForwardTraining() call, should be passed as inputs here.

epsilon

Input. Epsilon value used in the batch normalization formula. Its value should be equal to or greater than the value defined for CUDNN_BN_MIN_EPSILON in cudnn.h.

Supported configurations

This function supports the following combinations of data types for various descriptors.

Returns

CUDNN_STATUS_SUCCESS

The computation was performed successfully.

CUDNN_STATUS_NOT_SUPPORTED

The function does not support the provided configuration.

CUDNN_STATUS_BAD_PARAM

At least one of the following conditions are met:

• One of the pointers alpha, beta, x, y, bnScale, bnBias, estimatedMean, estimatedInvVariance is NULL.
• The number of xDesc or yDesc tensor descriptor dimensions is not within the range of [4,5] (only 4D and 5D tensors are supported.)
• bnScaleBiasMeanVarDesc dimensions are not 1xCx1x1 for 4D and 1xCx1x1x1 for 5D for spatial, and are not 1xCxHxW for 4D and 1xCxDxHxW for 5D for per-activation mode.
• epsilon value is less than CUDNN_BN_MIN_EPSILON.
• Dimensions or data types mismatch for xDesc, yDesc.

3.2.4. cudnnCopyAlgorithmDescriptor()

This function has been deprecated in cuDNN 8.0.

3.2.5. cudnnCreate()

            

            
cudnnStatus_t cudnnCreate(cudnnHandle_t *handle)
        

This function initializes the cuDNN library and creates a handle to an opaque structure holding the cuDNN library context. It allocates hardware resources on the host and device and must be called prior to making any other cuDNN library calls.

The cuDNN library handle is tied to the current CUDA device (context). To use the library on multiple devices, one cuDNN handle needs to be created for each device.

For a given device, multiple cuDNN handles with different configurations (for example, different current CUDA streams) may be created. Because cudnnCreate() allocates some internal resources, the release of those resources by calling cudnnDestroy() will implicitly call cudaDeviceSynchronize; therefore, the recommended best practice is to call cudnnCreate/cudnnDestroy outside of performance-critical code paths.

For multithreaded applications that use the same device from different threads, the recommended programming model is to create one (or a few, as is convenient) cuDNN handle(s) per thread and use that cuDNN handle for the entire life of the thread.

Parameters

handle

Output. Pointer to pointer where to store the address to the allocated cuDNN handle. For more information, see cudnnHandle_t.

Returns

CUDNN_STATUS_BAD_PARAM

Invalid (NULL) input pointer supplied.

CUDNN_STATUS_NOT_INITIALIZED

No compatible GPU found, CUDA driver not installed or disabled, CUDA runtime API initialization failed.

CUDNN_STATUS_ARCH_MISMATCH

NVIDIA GPU architecture is too old.

CUDNN_STATUS_ALLOC_FAILED

Host memory allocation failed.

CUDNN_STATUS_INTERNAL_ERROR

CUDA resource allocation failed.

CUDNN_STATUS_LICENSE_ERROR

cuDNN license validation failed (only when the feature is enabled).

CUDNN_STATUS_SUCCESS

cuDNN handle was created successfully.

3.2.6. cudnnCreateActivationDescriptor()

            

            
cudnnStatus_t cudnnCreateActivationDescriptor(
        cudnnActivationDescriptor_t   *activationDesc)
        

This function creates an activation descriptor object by allocating the memory needed to hold its opaque structure. For more information, see cudnnActivationDescriptor_t.

Returns

CUDNN_STATUS_SUCCESS

The object was created successfully.

CUDNN_STATUS_ALLOC_FAILED

The resources could not be allocated.

3.2.7. cudnnCreateAlgorithmDescriptor()

This function has been deprecated in cuDNN 8.0.

            

            
cudnnStatus_t cudnnCreateAlgorithmDescriptor(
    cudnnAlgorithmDescriptor_t *algoDesc)
        

This function creates an algorithm descriptor object by allocating the memory needed to hold its opaque structure.

Returns

CUDNN_STATUS_SUCCESS

The object was created successfully.

CUDNN_STATUS_ALLOC_FAILED

The resources could not be allocated.

3.2.8. cudnnCreateAlgorithmPerformance()

            

            
cudnnStatus_t cudnnCreateAlgorithmPerformance(
    cudnnAlgorithmPerformance_t *algoPerf,
    int                         numberToCreate)
        

This function creates multiple algorithm performance objects by allocating the memory needed to hold their opaque structures.

Returns

CUDNN_STATUS_SUCCESS

The object was created successfully.

CUDNN_STATUS_ALLOC_FAILED

The resources could not be allocated.

3.2.9. cudnnCreateDropoutDescriptor()

            

            
cudnnStatus_t cudnnCreateDropoutDescriptor(
    cudnnDropoutDescriptor_t    *dropoutDesc)
        

This function creates a generic dropout descriptor object by allocating the memory needed to hold its opaque structure. For more information, see cudnnDropoutDescriptor_t.

Returns

CUDNN_STATUS_SUCCESS

The object was created successfully.

CUDNN_STATUS_ALLOC_FAILED

The resources could not be allocated.

3.2.10. cudnnCreateFilterDescriptor()

            

            
cudnnStatus_t cudnnCreateFilterDescriptor(
    cudnnFilterDescriptor_t *filterDesc)
        

This function creates a filter descriptor object by allocating the memory needed to hold its opaque structure. For more information, see cudnnFilterDescriptor_t.

Returns

CUDNN_STATUS_SUCCESS

The object was created successfully.

CUDNN_STATUS_ALLOC_FAILED

The resources could not be allocated.

3.2.11. cudnnCreateLRNDescriptor()

            

            
cudnnStatus_t cudnnCreateLRNDescriptor(
            cudnnLRNDescriptor_t    *poolingDesc)
        

This function allocates the memory needed to hold the data needed for LRN and DivisiveNormalization layers operation and returns a descriptor used with subsequent layer forward and backward calls.

Returns

CUDNN_STATUS_SUCCESS

The object was created successfully.

CUDNN_STATUS_ALLOC_FAILED

The resources could not be allocated.

cudnnCreateOpTensorDescriptor()

            

            
cudnnStatus_t cudnnCreateOpTensorDescriptor(
    cudnnOpTensorDescriptor_t* 	opTensorDesc)
        

This function creates a tensor pointwise math descriptor. For more information, see cudnnOpTensorDescriptor_t.

Parameters

opTensorDesc

Output. Pointer to the structure holding the description of the tensor pointwise math such as add, multiply, and more.

Returns

CUDNN_STATUS_SUCCESS

The function returned successfully.

CUDNN_STATUS_BAD_PARAM

Tensor pointwise math descriptor passed to the function is invalid.

CUDNN_STATUS_ALLOC_FAILED

Memory allocation for this tensor pointwise math descriptor failed.

3.2.13. cudnnCreatePoolingDescriptor()

            

            
cudnnStatus_t cudnnCreatePoolingDescriptor(
    cudnnPoolingDescriptor_t    *poolingDesc)
        

This function creates a pooling descriptor object by allocating the memory needed to hold its opaque structure.

Returns

CUDNN_STATUS_SUCCESS

The object was created successfully.

CUDNN_STATUS_ALLOC_FAILED

The resources could not be allocated.

3.2.14. cudnnCreateReduceTensorDescriptor()

            

            
cudnnStatus_t cudnnCreateReduceTensorDescriptor(
	cudnnReduceTensorDescriptor_t*	reduceTensorDesc)
        

This function creates a reduced tensor descriptor object by allocating the memory needed to hold its opaque structure.

Returns

CUDNN_STATUS_SUCCESS

The object was created successfully.

CUDNN_STATUS_BAD_PARAM

reduceTensorDesc is a NULL pointer.

CUDNN_STATUS_ALLOC_FAILED

The resources could not be allocated.

3.2.15. cudnnCreateSpatialTransformerDescriptor()

            

            
cudnnStatus_t cudnnCreateSpatialTransformerDescriptor(
    cudnnSpatialTransformerDescriptor_t *stDesc)
        

This function creates a generic spatial transformer descriptor object by allocating the memory needed to hold its opaque structure.

Returns

CUDNN_STATUS_SUCCESS

The object was created successfully.

CUDNN_STATUS_ALLOC_FAILED

The resources could not be allocated.

3.2.16. cudnnCreateTensorDescriptor()

            

            
cudnnStatus_t cudnnCreateTensorDescriptor(
    cudnnTensorDescriptor_t *tensorDesc)
        

This function creates a generic tensor descriptor object by allocating the memory needed to hold its opaque structure. The data is initialized to all zeros.

Parameters

tensorDesc

Input. Pointer to pointer where the address to the allocated tensor descriptor object should be stored.

Returns

CUDNN_STATUS_BAD_PARAM

Invalid input argument.

CUDNN_STATUS_ALLOC_FAILED

The resources could not be allocated.

CUDNN_STATUS_SUCCESS

The object was created successfully.

3.2.17. cudnnCreateTensorTransformDescriptor()

            

            
cudnnStatus_t cudnnCreateTensorTransformDescriptor(
	cudnnTensorTransformDescriptor_t *transformDesc);
        

This function creates a tensor transform descriptor object by allocating the memory needed to hold its opaque structure. The tensor data is initialized to be all zero. Use the cudnnSetTensorTransformDescriptor() function to initialize the descriptor created by this function.

Parameters

transformDesc

Output. A pointer to an uninitialized tensor transform descriptor.

Returns

CUDNN_STATUS_SUCCESS

The descriptor object was created successfully.

CUDNN_STATUS_BAD_PARAM

The transformDesc is NULL.

CUDNN_STATUS_ALLOC_FAILED

The memory allocation failed.

3.2.18. cudnnDeriveBNTensorDescriptor()

            

            
cudnnStatus_t cudnnDeriveBNTensorDescriptor(
    cudnnTensorDescriptor_t         derivedBnDesc,
    const cudnnTensorDescriptor_t   xDesc,
    cudnnBatchNormMode_t            mode)
        

This function derives a secondary tensor descriptor for the batch normalization scale, invVariance, bnBias, and bnScale subtensors from the layer's x data descriptor.

Use the tensor descriptor produced by this function as the bnScaleBiasMeanVarDesc parameter for the cudnnBatchNormalizationForwardInference() and cudnnBatchNormalizationForwardTraining() functions, and as the bnScaleBiasDiffDesc parameter in the cudnnBatchNormalizationBackward() function. The resulting dimensions will be:

• 1xCx1x1 for 4D and 1xCx1x1x1 for 5D for BATCHNORM_MODE_SPATIAL
• 1xCxHxW for 4D and 1xCxDxHxW for 5D for BATCHNORM_MODE_PER_ACTIVATION mode

For HALF input data type the resulting tensor descriptor will have a FLOAT type. For other data types, it will have the same type as the input data.

Parameters

derivedBnDesc

Output. Handle to a previously created tensor descriptor.

xDesc

Input. Handle to a previously created and initialized layer's x data descriptor.

mode

Input. Batch normalization layer mode of operation.

Returns

CUDNN_STATUS_SUCCESS

The computation was performed successfully.

CUDNN_STATUS_BAD_PARAM

Invalid Batch Normalization mode.

3.2.19. cudnnDeriveNormTensorDescriptor()

            

            
cudnnStatus_t CUDNNWINAPI
cudnnDeriveNormTensorDescriptor(cudnnTensorDescriptor_t derivedNormScaleBiasDesc,
                                cudnnTensorDescriptor_t derivedNormMeanVarDesc,
                                const cudnnTensorDescriptor_t xDesc,
   	                         cudnnNormMode_t mode,
                                int groupCnt)
        

This function derives tensor descriptors for the normalization mean, invariance, normBias, and normScale subtensors from the layer's x data descriptor and norm mode. normalization, mean, and invariance share the same descriptor while bias and scale share the same descriptor.

Use the tensor descriptor produced by this function as the normScaleBiasDesc or normMeanVarDesc parameter for the cudnnNormalizationForwardInference() and cudnnNormalizationForwardTraining() functions, and as the dNormScaleBiasDesc and normMeanVarDesc parameter in the cudnnNormalizationBackward() function. The resulting dimensions will be:

• 1xCx1x1 for 4D and 1xCx1x1x1 for 5D for CUDNN_NORM_PER_ACTIVATION
• 1xCxHxW for 4D and 1xCxDxHxW for 5D for CUDNN_NORM_PER_CHANNEL mode

For HALF input data type the resulting tensor descriptor will have a FLOAT type. For other data types, it will have the same type as the input data.

• Only 4D and 5D tensors are supported.
• The derivedNormScaleBiasDesc and derivedNormMeanVarDesc should be created first using cudnnCreateTensorDescriptor().
• xDesc is the descriptor for the layer's x data and has to be set up with proper dimensions prior to calling this function.

Parameters

derivedNormScaleBiasDesc

Output. Handle to a previously created tensor descriptor.

derivedNormMeanVarDesc

Output. Handle to a previously created tensor descriptor.

xDesc

Input. Handle to a previously created and initialized layer's x data descriptor.

mode

Input. The normalization layer mode of operation.

Returns

CUDNN_STATUS_SUCCESS

The computation was performed successfully.

CUDNN_STATUS_BAD_PARAM

Invalid Batch Normalization mode.

3.2.20. cudnnDestroy()

            

            
cudnnStatus_t cudnnDestroy(cudnnHandle_t handle)
        

This function releases the resources used by the cuDNN handle. This function is usually the last call with a particular handle to the cuDNN handle. Because cudnnCreate() allocates some internal resources, the release of those resources by calling cudnnDestroy() will implicitly call cudaDeviceSynchronize; therefore, the recommended best practice is to call cudnnCreate/cudnnDestroy outside of performance-critical code paths.

Parameters

handle

Input. Pointer to the cuDNN handle to be destroyed.

Returns

CUDNN_STATUS_SUCCESS

The cuDNN context destruction was successful.

CUDNN_STATUS_BAD_PARAM

Invalid (NULL) pointer supplied.

3.2.21. cudnnDestroyActivationDescriptor()

            

            
cudnnStatus_t cudnnDestroyActivationDescriptor(
        cudnnActivationDescriptor_t activationDesc)
        

This function destroys a previously created activation descriptor object.

Returns

CUDNN_STATUS_SUCCESS

The object was destroyed successfully.

3.2.22. cudnnDestroyAlgorithmDescriptor()

This function has been deprecated in cuDNN 8.0.

            

            
cudnnStatus_t cudnnDestroyAlgorithmDescriptor(
        cudnnActivationDescriptor_t algorithmDesc)
        

This function destroys a previously created algorithm descriptor object.

Returns

CUDNN_STATUS_SUCCESS

The object was destroyed successfully.

3.2.23. cudnnDestroyAlgorithmPerformance()

            

            
cudnnStatus_t cudnnDestroyAlgorithmPerformance(
        cudnnAlgorithmPerformance_t     algoPerf)
        

This function destroys a previously created algorithm descriptor object.

Returns

CUDNN_STATUS_SUCCESS

The object was destroyed successfully.

3.2.24. cudnnDestroyDropoutDescriptor()

            

            
cudnnStatus_t cudnnDestroyDropoutDescriptor(
    cudnnDropoutDescriptor_t dropoutDesc)
        

This function destroys a previously created dropout descriptor object.

Returns

CUDNN_STATUS_SUCCESS

The object was destroyed successfully.

3.2.25. cudnnDestroyFilterDescriptor()

            

            
cudnnStatus_t cudnnDestroyFilterDescriptor(
    cudnnFilterDescriptor_t filterDesc)
        

This function destroys a previously created tensor 4D descriptor object.

Returns

CUDNN_STATUS_SUCCESS

The object was destroyed successfully.

3.2.26. cudnnDestroyLRNDescriptor()

            

            
cudnnStatus_t cudnnDestroyLRNDescriptor(
    cudnnLRNDescriptor_t lrnDesc)
        

This function destroys a previously created LRN descriptor object.

Returns

CUDNN_STATUS_SUCCESS

The object was destroyed successfully.

3.2.27. cudnnDestroyOpTensorDescriptor()

            

            
cudnnStatus_t cudnnDestroyOpTensorDescriptor(
    cudnnOpTensorDescriptor_t   opTensorDesc)
        

This function deletes a tensor pointwise math descriptor object.

Parameters

opTensorDesc

Input. Pointer to the structure holding the description of the tensor pointwise math to be deleted.

Returns

CUDNN_STATUS_SUCCESS

The function returned successfully.

3.2.28. cudnnDestroyPoolingDescriptor()

            

            
cudnnStatus_t cudnnDestroyPoolingDescriptor(
    cudnnPoolingDescriptor_t poolingDesc)
        

This function destroys a previously created pooling descriptor object.

Returns

CUDNN_STATUS_SUCCESS

The object was destroyed successfully.

3.2.29. cudnnDestroyReduceTensorDescriptor()

            

            
cudnnStatus_t cudnnDestroyReduceTensorDescriptor(
    cudnnReduceTensorDescriptor_t   tensorDesc)
        

This function destroys a previously created reduce tensor descriptor object. When the input pointer is NULL, this function performs no destroy operation.

Parameters

tensorDesc

Input. Pointer to the reduce tensor descriptor object to be destroyed.

Returns

CUDNN_STATUS_SUCCESS

The object was destroyed successfully.

3.2.30. cudnnDestroySpatialTransformerDescriptor()

            

            
cudnnStatus_t cudnnDestroySpatialTransformerDescriptor(
    cudnnSpatialTransformerDescriptor_t stDesc)
        

This function destroys a previously created spatial transformer descriptor object.

Returns

CUDNN_STATUS_SUCCESS

The object was destroyed successfully.

3.2.31. cudnnDestroyTensorDescriptor()

            

            
cudnnStatus_t cudnnDestroyTensorDescriptor(cudnnTensorDescriptor_t tensorDesc)
        

This function destroys a previously created tensor descriptor object. When the input pointer is NULL, this function performs no destroy operation.

Parameters

tensorDesc

Input. Pointer to the tensor descriptor object to be destroyed.

Returns

CUDNN_STATUS_SUCCESS

The object was destroyed successfully.

3.2.32. cudnnDestroyTensorTransformDescriptor()

            

            
cudnnStatus_t cudnnDestroyTensorTransformDescriptor(
	cudnnTensorTransformDescriptor_t transformDesc);
        

Destroys a previously created tensor transform descriptor.

Parameters

transformDesc

Input. The tensor transform descriptor to be destroyed.

Returns

CUDNN_STATUS_SUCCESS

The descriptor was destroyed successfully.

3.2.33. cudnnDivisiveNormalizationForward()

            

            
cudnnStatus_t cudnnDivisiveNormalizationForward(
    cudnnHandle_t                    handle,
    cudnnLRNDescriptor_t             normDesc,
    cudnnDivNormMode_t               mode,
    const void                      *alpha,
    const cudnnTensorDescriptor_t    xDesc,
    const void                      *x,
    const void                      *means,
    void                            *temp,
    void                            *temp2,
    const void                      *beta,
    const cudnnTensorDescriptor_t    yDesc,
    void                            *y)
        

This function performs the forward spatial DivisiveNormalization layer computation. It divides every value in a layer by the standard deviation of its spatial neighbors as described in What is the Best Multi-Stage Architecture for Object Recognition, Jarrett 2009, Local Contrast Normalization Layer section. Note that DivisiveNormalization only implements the x/max(c, sigma_x) portion of the computation, where sigma_x is the variance over the spatial neighborhood of x. The full LCN (Local Contrastive Normalization) computation can be implemented as a two-step process:

            

            
x_m = x-mean(x);
y = x_m/max(c, sigma(x_m));
        

The x-mean(x) which is often referred to as "subtractive normalization" portion of the computation can be implemented using cuDNN average pooling layer followed by a call to addTensor.

Parameters

handle

Input. Handle to a previously created cuDNN library descriptor.

normDesc

Input. Handle to a previously initialized LRN parameter descriptor. This descriptor is used for both LRN and DivisiveNormalization layers.

divNormMode

Input. DivisiveNormalization layer mode of operation. Currently only CUDNN_DIVNORM_PRECOMPUTED_MEANS is implemented. Normalization is performed using the means input tensor that is expected to be precomputed by the user.

alpha, beta

Input. Pointers to scaling factors (in host memory) used to blend the layer output value with prior value in the destination tensor as follows:

Copy

Copied!

            

            
dstValue = alpha[0]*resultValue + beta[0]*priorDstValue
        

For more information, see Scaling Parameters in the cuDNN Developer Guide.

xDesc, yDesc

Input. Tensor descriptor objects for the input and output tensors. Note that xDesc is shared between x, means, temp, and temp2 tensors.

x

Input. Input tensor data pointer in device memory.

means

Input. Input means tensor data pointer in device memory. Note that this tensor can be NULL (in that case its values are assumed to be zero during the computation). This tensor also doesn't have to contain means, these can be any values, a frequently used variation is a result of convolution with a normalized positive kernel (such as Gaussian).

temp, temp2

Workspace. Temporary tensors in device memory. These are used for computing intermediate values during the forward pass. These tensors do not have to be preserved as inputs from forward to the backward pass. Both use xDesc as their descriptor.

y

Output. Pointer in device memory to a tensor for the result of the forward DivisiveNormalization computation.

Returns

CUDNN_STATUS_SUCCESS

The computation was performed successfully.

CUDNN_STATUS_BAD_PARAM

At least one of the following conditions are met:

• One of the tensor pointers x, y, temp, temp2 is NULL.
• Number of input tensor or output tensor dimensions is outside of [4,5] range.
• A mismatch in dimensions between any two of the input or output tensors.
• For in-place computation when pointers x == y, a mismatch in strides between the input data and output data tensors.
• Alpha or beta pointer is NULL.
• LRN descriptor parameters are outside of their valid ranges.
• Any of the tensor strides are negative.

CUDNN_STATUS_UNSUPPORTED

The function does not support the provided configuration, for example, any of the input and output tensor strides mismatch (for the same dimension) is a non-supported configuration.

3.2.34. cudnnDropoutForward()

            

            
cudnnStatus_t cudnnDropoutForward(
    cudnnHandle_t                       handle,
    const cudnnDropoutDescriptor_t      dropoutDesc,
    const cudnnTensorDescriptor_t       xdesc,
    const void                         *x,
    const cudnnTensorDescriptor_t       ydesc,
    void                               *y,
    void                               *reserveSpace,
    size_t                              reserveSpaceSizeInBytes)
        

This function performs forward dropout operation over x returning results in y. If dropout was used as a parameter to cudnnSetDropoutDescriptor(), the approximately dropout fraction of x values will be replaced by a 0, and the rest will be scaled by 1/(1-dropout). This function should not be running concurrently with another cudnnDropoutForward() function using the same states.

Parameters

handle

Input. Handle to a previously created cuDNN context.

dropoutDesc

Input. Previously created dropout descriptor object.

xDesc

Input. Handle to a previously initialized tensor descriptor.

x

Input. Pointer to data of the tensor described by the xDesc descriptor.

yDesc

Input. Handle to a previously initialized tensor descriptor.

y

Output. Pointer to data of the tensor described by the yDesc descriptor.

reserveSpace

Output. Pointer to user-allocated GPU memory used by this function. It is expected that the contents of reserveSpace does not change between cudnnDropoutForward() and cudnnDropoutBackward() calls.

reserveSpaceSizeInBytes

Input. Specifies the size in bytes of the provided memory for the reserve space.

Returns

CUDNN_STATUS_SUCCESS

The call was successful.

CUDNN_STATUS_NOT_SUPPORTED

The function does not support the provided configuration.

CUDNN_STATUS_BAD_PARAM

At least one of the following conditions are met:

• The number of elements of input tensor and output tensors differ.
• The datatype of the input tensor and output tensors differs.
• The strides of the input tensor and output tensors differ and in-place operation is used (meaning, x and y pointers are equal).
• The provided reserveSpaceSizeInBytes is less than the value returned by cudnnDropoutGetReserveSpaceSize().
• cudnnSetDropoutDescriptor() has not been called on dropoutDesc with the non-NULLstates argument.

CUDNN_STATUS_EXECUTION_FAILED

The function failed to launch on the GPU.

3.2.35. cudnnDropoutGetReserveSpaceSize()

            

            
cudnnStatus_t cudnnDropoutGetReserveSpaceSize(
    cudnnTensorDescriptor_t     xDesc,
    size_t                     *sizeInBytes)
        

This function is used to query the amount of reserve needed to run dropout with the input dimensions given by xDesc. The same reserve space is expected to be passed to cudnnDropoutForward() and cudnnDropoutBackward(), and its contents is expected to remain unchanged between cudnnDropoutForward() and cudnnDropoutBackward() calls.

Parameters

xDesc

Input. Handle to a previously initialized tensor descriptor, describing input to a dropout operation.

sizeInBytes

Output. Amount of GPU memory needed as reserve space to be able to run dropout with an input tensor descriptor specified by xDesc.

Returns

CUDNN_STATUS_SUCCESS

The query was successful.

3.2.36. cudnnDropoutGetStatesSize()

            

            
cudnnStatus_t cudnnDropoutGetStatesSize(
    cudnnHandle_t       handle,
    size_t             *sizeInBytes)
        

This function is used to query the amount of space required to store the states of the random number generators used by cudnnDropoutForward() function.

Parameters

handle

Input. Handle to a previously created cuDNN context.

sizeInBytes

Output. Amount of GPU memory needed to store random generator states.

Returns

CUDNN_STATUS_SUCCESS

The query was successful.

3.2.37. cudnnGetActivationDescriptor()

            

            
cudnnStatus_t cudnnGetActivationDescriptor(
        const cudnnActivationDescriptor_t   activationDesc,
        cudnnActivationMode_t              *mode,
        cudnnNanPropagation_t              *reluNanOpt,
        double                             *coef)
        

This function queries a previously initialized generic activation descriptor object.

Parameters

activationDesc

Input. Handle to a previously created activation descriptor.

mode

Output. Enumerant to specify the activation mode.

reluNanOpt

Output. Enumerant to specify the Nan propagation mode.

coef

Output. Floating point number to specify the clipping threshold when the activation mode is set to CUDNN_ACTIVATION_CLIPPED_RELU or to specify the alpha coefficient when the activation mode is set to CUDNN_ACTIVATION_ELU.

Returns

CUDNN_STATUS_SUCCESS

The object was queried successfully.

3.2.38. cudnnGetAlgorithmDescriptor()

This function has been deprecated in cuDNN 8.0.

            

            
cudnnStatus_t cudnnGetAlgorithmDescriptor(        
        const cudnnAlgorithmDescriptor_t    algoDesc,
        cudnnAlgorithm_t                    *algorithm)
        

This function queries a previously initialized generic algorithm descriptor object.

Parameters

algorithmDesc

Input. Handle to a previously created algorithm descriptor.

algorithm

Input. Struct to specify the algorithm.

Returns

CUDNN_STATUS_SUCCESS

The object was queried successfully.

3.2.39. cudnnGetAlgorithmPerformance()

This function has been deprecated in cuDNN 8.0.

            

            
cudnnStatus_t cudnnGetAlgorithmPerformance(
        const cudnnAlgorithmPerformance_t   algoPerf,
        cudnnAlgorithmDescriptor_t*         algoDesc,
        cudnnStatus_t*                      status,
        float*                              time,
        size_t*                             memory)
        

This function queries a previously initialized generic algorithm performance object.

Parameters

algoPerf

Input/Output. Handle to a previously created algorithm performance object.

algoDesc

Output. The algorithm descriptor which the performance results describe.

status

Output. The cuDNN status returned from running the algoDesc algorithm.

timecoef

Output. The GPU time spent running the algoDesc algorithm.

memory

Output. The GPU memory needed to run the algoDesc algorithm.

Returns

CUDNN_STATUS_SUCCESS

The object was queried successfully.

3.2.40. cudnnGetAlgorithmSpaceSize()

This function has been deprecated in cuDNN 8.0.

            

            
cudnnStatus_t cudnnGetAlgorithmSpaceSize(    
    cudnnHandle_t               handle,
    cudnnAlgorithmDescriptor_t  algoDesc,
    size_t*                     algoSpaceSizeInBytes)
        

This function queries for the amount of host memory needed to call cudnnSaveAlgorithm(), much like the “get workspace size” function query for the amount of device memory needed.

Parameters

handle

Input. Handle to a previously created cuDNN context.

algoDesc

Input. A previously created algorithm descriptor.

algoSpaceSizeInBytes

Output. Amount of host memory needed as a workspace to be able to save the metadata from the specified algoDesc.

Returns

CUDNN_STATUS_SUCCESS

The function launched successfully.

CUDNN_STATUS_BAD_PARAM

At least one of the arguments is NULL.

3.2.41. cudnnGetCallback()

            

            
cudnnStatus_t cudnnGetCallback(
        unsigned            mask,
        void                **udata,
        cudnnCallback_t     fptr)
        

This function queries the internal states of cuDNN error reporting functionality.

Parameters

mask

Output. Pointer to the address where the current internal error reporting message bit mask will be outputted.

udata

Output. Pointer to the address where the current internally stored udata address will be stored.

fptr

Output. Pointer to the address where the current internally stored callback function pointer will be stored. When the built-in default callback function is used, NULL will be outputted.

Returns

CUDNN_STATUS_SUCCESS

The function launched successfully.

CUDNN_STATUS_BAD_PARAM

If any of the input parameters are NULL.

3.2.42. cudnnGetCudartVersion()

            

            
size_t cudnnGetCudartVersion()
        

The same version of a given cuDNN library can be compiled against different NVIDIA^® CUDA^® Toolkit™ versions. This routine returns the CUDA Toolkit version that the currently used cuDNN library has been compiled against.

3.2.43. cudnnGetDropoutDescriptor()

            

            
cudnnStatus_t cudnnGetDropoutDescriptor(
    cudnnDropoutDescriptor_t    dropoutDesc,
    cudnnHandle_t               handle,
    float                      *dropout,
    void                       **states,
    unsigned long long         *seed)
        

This function queries the fields of a previously initialized dropout descriptor.

Parameters

dropoutDesc

Input. Previously initialized dropout descriptor.

handle

Input. Handle to a previously created cuDNN context.

dropout

Output. The probability with which the value from input is set to 0 during the dropout layer.

states

Output. Pointer to user-allocated GPU memory that holds random number generator states.

seed

Output. Seed used to initialize random number generator states.

Returns

CUDNN_STATUS_SUCCESS

The call was successful.

CUDNN_STATUS_BAD_PARAM

One or more of the arguments was an invalid pointer.

3.2.44. cudnnGetErrorString()

            

            
const char * cudnnGetErrorString(cudnnStatus_t status)
        

This function converts the cuDNN status code to a NULL terminated (ASCIIZ) static string. For example, when the input argument is CUDNN_STATUS_SUCCESS, the returned string is CUDNN_STATUS_SUCCESS. When an invalid status value is passed to the function, the returned string is CUDNN_UNKNOWN_STATUS.

Parameters

status

Input. cuDNN enumerant status code.

Returns

Pointer to a static, NULL terminated string with the status name.

3.2.45. cudnnGetFilter4dDescriptor()

            

            
cudnnStatus_t cudnnGetFilter4dDescriptor(
    const cudnnFilterDescriptor_t     filterDesc,
    cudnnDataType_t            *dataType,
    cudnnTensorFormat_t        *format,
    int                        *k,
    int                        *c,
    int                        *h,
    int                        *w)
        

This function queries the parameters of the previously initialized filter descriptor object.

Parameters

filterDesc

Input. Handle to a previously created filter descriptor.

datatype

Output. Data type.

format

Output. Type of format.

k

Output. Number of output feature maps.

c

Output. Number of input feature maps.

h

Output. Height of each filter.

w

Output. Width of each filter.

Returns

CUDNN_STATUS_SUCCESS

The object was set successfully.

3.2.46. cudnnGetFilterNdDescriptor()

            

            
cudnnStatus_t cudnnGetFilterNdDescriptor(
    const cudnnFilterDescriptor_t   wDesc,
    int                             nbDimsRequested,
    cudnnDataType_t                *dataType,
    cudnnTensorFormat_t            *format,
    int                            *nbDims,
    int                             filterDimA[])
        

This function queries a previously initialized filter descriptor object.

Parameters

wDesc

Input. Handle to a previously initialized filter descriptor.

nbDimsRequested

Input. Dimension of the expected filter descriptor. It is also the minimum size of the arrays filterDimA in order to be able to hold the results

datatype

Output. Data type.

format

Output. Type of format.

nbDims

Output. Actual dimension of the filter.

filterDimA

Output. Array of dimension of at least nbDimsRequested that will be filled with the filter parameters from the provided filter descriptor.

Returns

CUDNN_STATUS_SUCCESS

The object was set successfully.

CUDNN_STATUS_BAD_PARAM

The parameter nbDimsRequested is negative.

3.2.47. cudnnGetFilterSizeInBytes()

            

            
cudnnStatus_t
cudnnGetFilterSizeInBytes(const cudnnFilterDescriptor_t filterDesc, size_t *size) ;
        

This function returns the size of the filter tensor in memory with respect to the given descriptor. It can be used to know the amount of GPU memory to be allocated to hold that filter tensor.

Parameters

filterDesc

Input. handle to a previously initialized filter descriptor.

size

Output. size in bytes needed to hold the tensor in GPU memory.

Returns

CUDNN_STATUS_SUCCESS

filterDescis valid.

CUDNN_STATUS_BAD_PARAM

filerDescis invald.

3.2.48. cudnnGetLRNDescriptor()

            

            
cudnnStatus_t cudnnGetLRNDescriptor(
    cudnnLRNDescriptor_t    normDesc,
    unsigned               *lrnN,
    double                 *lrnAlpha,
    double                 *lrnBeta,
    double                 *lrnK)
        

This function retrieves values stored in the previously initialized LRN descriptor object.

Parameters

normDesc

Output. Handle to a previously created LRN descriptor.

lrnN, lrnAlpha, lrnBeta, lrnK

Output. Pointers to receive values of parameters stored in the descriptor object. See cudnnSetLRNDescriptor() for more details. Any of these pointers can be NULL (no value is returned for the corresponding parameter).

Returns

CUDNN_STATUS_SUCCESS

Function completed successfully.

3.2.49. cudnnGetOpTensorDescriptor()

            

            
cudnnStatus_t cudnnGetOpTensorDescriptor(
    const cudnnOpTensorDescriptor_t opTensorDesc,
    cudnnOpTensorOp_t               *opTensorOp,
    cudnnDataType_t                 *opTensorCompType,
    cudnnNanPropagation_t           *opTensorNanOpt)
        

This function returns the configuration of the passed tensor pointwise math descriptor.

Parameters

opTensorDesc

Input. Tensor pointwise math descriptor passed to get the configuration from.

opTensorOp

Output. Pointer to the tensor pointwise math operation type, associated with this tensor pointwise math descriptor.

opTensorCompType

Output. Pointer to the cuDNN data-type associated with this tensor pointwise math descriptor.

opTensorNanOpt

Output. Pointer to the NAN propagation option associated with this tensor pointwise math descriptor.

Returns

CUDNN_STATUS_SUCCESS

The function returned successfully.

CUDNN_STATUS_BAD_PARAM

Input tensor pointwise math descriptor passed is invalid.

3.2.50. cudnnGetPooling2dDescriptor()

            

            
cudnnStatus_t cudnnGetPooling2dDescriptor(
    const cudnnPoolingDescriptor_t      poolingDesc,
    cudnnPoolingMode_t                 *mode,
    cudnnNanPropagation_t              *maxpoolingNanOpt,
    int                                *windowHeight,
    int                                *windowWidth,
    int                                *verticalPadding,
    int                                *horizontalPadding,
    int                                *verticalStride,
    int                                *horizontalStride)
        

This function queries a previously created 2D pooling descriptor object.

Parameters

poolingDesc

Input. Handle to a previously created pooling descriptor.

mode

Output. Enumerant to specify the pooling mode.

maxpoolingNanOpt

Output. Enumerant to specify the Nan propagation mode.

windowHeight

Output. Height of the pooling window.

windowWidth

Output. Width of the pooling window.

verticalPadding

Output. Size of vertical padding.

horizontalPadding

Output. Size of horizontal padding.

verticalStride

Output. Pooling vertical stride.

horizontalStride

Output. Pooling horizontal stride.

Returns

CUDNN_STATUS_SUCCESS

The object was set successfully.

3.2.51. cudnnGetPooling2dForwardOutputDim()

            

            
cudnnStatus_t cudnnGetPooling2dForwardOutputDim(
    const cudnnPoolingDescriptor_t      poolingDesc,
    const cudnnTensorDescriptor_t       inputDesc,
    int                                *outN,
    int                                *outC,
    int                                *outH,
    int                                *outW)
        

This function provides the output dimensions of a tensor after 2d pooling has been applied. Each dimension h and w of the output images is computed as follows:

            

            
outputDim = 1 + (inputDim + 2*padding - windowDim)/poolingStride;
        

Parameters

poolingDesc

Input. Handle to a previously initialized pooling descriptor.

inputDesc

Input. Handle to the previously initialized input tensor descriptor.

N

Output. Number of images in the output.

C

Output. Number of channels in the output.

H

Output. Height of images in the output.

W

Output. Width of images in the output.

Returns

CUDNN_STATUS_SUCCESS

The function launched successfully.

CUDNN_STATUS_BAD_PARAM

At least one of the following conditions are met:

• poolingDesc has not been initialized.
• poolingDesc or inputDesc has an invalid number of dimensions (2 and 4 respectively are required).

3.2.52. cudnnGetPoolingNdDescriptor()

            

            
cudnnStatus_t cudnnGetPoolingNdDescriptor(
const cudnnPoolingDescriptor_t      poolingDesc,
int                                 nbDimsRequested,
cudnnPoolingMode_t                 *mode,
cudnnNanPropagation_t              *maxpoolingNanOpt,
int                                *nbDims,
int                                 windowDimA[],
int                                 paddingA[],
int                                 strideA[])
        

This function queries a previously initialized generic pooling descriptor object.

Parameters

poolingDesc

Input. Handle to a previously created pooling descriptor.

nbDimsRequested

Input. Dimension of the expected pooling descriptor. It is also the minimum size of the arrays windowDimA, paddingA, and strideA in order to be able to hold the results.

mode

Output. Enumerant to specify the pooling mode.

maxpoolingNanOpt

Input. Enumerant to specify the Nan propagation mode.

nbDims

Output. Actual dimension of the pooling descriptor.

windowDimA

Output. Array of dimension of at least nbDimsRequested that will be filled with the window parameters from the provided pooling descriptor.

paddingA

Output. Array of dimension of at least nbDimsRequested that will be filled with the padding parameters from the provided pooling descriptor.

strideA

Output. Array of dimension at least nbDimsRequested that will be filled with the stride parameters from the provided pooling descriptor.

Returns

CUDNN_STATUS_SUCCESS

The object was queried successfully.

CUDNN_STATUS_NOT_SUPPORTED

The parameter nbDimsRequested is greater than CUDNN_DIM_MAX.

3.2.53. cudnnGetPoolingNdForwardOutputDim()

            

            
cudnnStatus_t cudnnGetPoolingNdForwardOutputDim(
    const cudnnPoolingDescriptor_t  poolingDesc,
    const cudnnTensorDescriptor_t   inputDesc,
    int                             nbDims,
    int                             outDimA[])
        

This function provides the output dimensions of a tensor after Nd pooling has been applied. Each dimension of the (nbDims-2)-D images of the output tensor is computed as follows:

            

            
outputDim = 1 + (inputDim + 2*padding - windowDim)/poolingStride;
        

Parameters

poolingDesc

Input. Handle to a previously initialized pooling descriptor.

inputDesc

Input. Handle to the previously initialized input tensor descriptor.

nbDims

Input. Number of dimensions in which pooling is to be applied.

outDimA

Output. Array of nbDims output dimensions.

Returns

CUDNN_STATUS_SUCCESS

The function launched successfully.

CUDNN_STATUS_BAD_PARAM

At least one of the following conditions are met:

• poolingDesc has not been initialized.
• The value of nbDims is inconsistent with the dimensionality of poolingDesc and inputDesc.

3.2.54. cudnnGetProperty()

            

            
cudnnStatus_t cudnnGetProperty(
    libraryPropertyType     type,
    int                    *value)
        

This function writes a specific part of the cuDNN library version number into the provided host storage.

Parameters

type

Input. Enumerant type that instructs the function to report the numerical value of the cuDNN major version, minor version, or the patch level.

value

Output. Host pointer where the version information should be written.

Returns

CUDNN_STATUS_INVALID_VALUE

Invalid value of the type argument.

CUDNN_STATUS_SUCCESS

Version information was stored successfully at the provided address.

3.2.55. cudnnGetReduceTensorDescriptor()

            

            
cudnnStatus_t cudnnGetReduceTensorDescriptor(
    const cudnnReduceTensorDescriptor_t reduceTensorDesc,
    cudnnReduceTensorOp_t               *reduceTensorOp,
    cudnnDataType_t                     *reduceTensorCompType,
    cudnnNanPropagation_t               *reduceTensorNanOpt,
    cudnnReduceTensorIndices_t          *reduceTensorIndices,
    cudnnIndicesType_t                  *reduceTensorIndicesType)
        

This function queries a previously initialized reduce tensor descriptor object.

Parameters

reduceTensorDesc

Input. Pointer to a previously initialized reduce tensor descriptor object.

reduceTensorOp

Output. Enumerant to specify the reduce tensor operation.

reduceTensorCompType

Output. Enumerant to specify the computation datatype of the reduction.

reduceTensorNanOpt

Input. Enumerant to specify the Nan propagation mode.

reduceTensorIndices

Output. Enumerant to specify the reduced tensor indices.

reduceTensorIndicesType

Output. Enumerant to specify the reduce tensor indices type.

Returns

CUDNN_STATUS_SUCCESS

The object was queried successfully.

CUDNN_STATUS_BAD_PARAM

reduceTensorDesc is NULL.

3.2.56. cudnnGetReductionIndicesSize()

            

            
cudnnStatus_t cudnnGetReductionIndicesSize(
    cudnnHandle_t                       handle,
    const cudnnReduceTensorDescriptor_t reduceDesc,
    const cudnnTensorDescriptor_t       aDesc,
    const cudnnTensorDescriptor_t       cDesc,
    size_t                              *sizeInBytes)
        

This is a helper function to return the minimum size of the index space to be passed to the reduction given the input and output tensors.

Parameters

handle

Input. Handle to a previously created cuDNN library descriptor.

reduceDesc

Input. Pointer to a previously initialized reduce tensor descriptor object.

aDesc

Input. Pointer to the input tensor descriptor.

cDesc

Input. Pointer to the output tensor descriptor.

sizeInBytes

Output. Minimum size of the index space to be passed to the reduction.

Returns

CUDNN_STATUS_SUCCESS

The index space size is returned successfully.

3.2.57. cudnnGetReductionWorkspaceSize()

            

            
cudnnStatus_t cudnnGetReductionWorkspaceSize(
    cudnnHandle_t                       handle,
    const cudnnReduceTensorDescriptor_t reduceDesc,
    const cudnnTensorDescriptor_t       aDesc,
    const cudnnTensorDescriptor_t       cDesc,
    size_t                              *sizeInBytes)
        

This is a helper function to return the minimum size of the workspace to be passed to the reduction given the input and output tensors.

Parameters

handle

Input. Handle to a previously created cuDNN library descriptor.

reduceDesc

Input. Pointer to a previously initialized reduce tensor descriptor object.

aDesc

Input. Pointer to the input tensor descriptor.

cDesc

Input. Pointer to the output tensor descriptor.

sizeInBytes

Output. Minimum size of the index space to be passed to the reduction.

Returns

CUDNN_STATUS_SUCCESS

The workspace size is returned successfully.

3.2.58. cudnnGetStream()

            

            
cudnnStatus_t cudnnGetStream(
    cudnnHandle_t   handle,
    cudaStream_t   *streamId)
        

This function retrieves the user CUDA stream programmed in the cuDNN handle. When the user's CUDA stream is not set in the cuDNN handle, this function reports the null-stream.

Parameters

handle

Input. Pointer to the cuDNN handle.

streamID

Output. Pointer where the current CUDA stream from the cuDNN handle should be stored.

Returns

CUDNN_STATUS_BAD_PARAM

Invalid (NULL) handle.

CUDNN_STATUS_SUCCESS

The stream identifier was retrieved successfully.

3.2.59. cudnnGetTensor4dDescriptor()

            

            
cudnnStatus_t cudnnGetTensor4dDescriptor(
    const cudnnTensorDescriptor_t  tensorDesc,
    cudnnDataType_t         *dataType,
    int                     *n,
    int                     *c,
    int                     *h,
    int                     *w,
    int                     *nStride,
    int                     *cStride,
    int                     *hStride,
    int                     *wStride)
        

This function queries the parameters of the previously initialized tensor4D descriptor object.

Parameters

tensorDesc

Input. Handle to a previously initialized tensor descriptor.

datatype

Output. Data type.

n

Output. Number of images.

c

Output. Number of feature maps per image.

h

Output. Height of each feature map.

w

Output. Width of each feature map.

nStride

Output. Stride between two consecutive images.

cStride

Output. Stride between two consecutive feature maps.

hStride

Output. Stride between two consecutive rows.

wStride

Output. Stride between two consecutive columns.

Returns

CUDNN_STATUS_SUCCESS

The operation succeeded.

3.2.60. cudnnGetTensorNdDescriptor()

            

            
cudnnStatus_t cudnnGetTensorNdDescriptor(
    const cudnnTensorDescriptor_t   tensorDesc,
    int                             nbDimsRequested,
    cudnnDataType_t                *dataType,
    int                            *nbDims,
    int                             dimA[],
    int                             strideA[])
        

This function retrieves values stored in a previously initialized tensor descriptor object.

Parameters

tensorDesc

Input. Handle to a previously initialized tensor descriptor.

nbDimsRequested

Input. Number of dimensions to extract from a given tensor descriptor. It is also the minimum size of the arrays dimA and strideA. If this number is greater than the resulting nbDims[0], only nbDims[0] dimensions will be returned.

datatype

Output. Data type.

nbDims

Output. Actual number of dimensions of the tensor will be returned in nbDims[0].

dimA

Output. Array of dimensions of at least nbDimsRequested that will be filled with the dimensions from the provided tensor descriptor.

strideA

Output. Array of dimension of at least nbDimsRequested that will be filled with the strides from the provided tensor descriptor.

Returns

CUDNN_STATUS_SUCCESS

The results were returned successfully.

CUDNN_STATUS_BAD_PARAM

Either tensorDesc or nbDims pointer is NULL.

3.2.61. cudnnGetTensorSizeInBytes()

            

            
cudnnStatus_t cudnnGetTensorSizeInBytes(
    const cudnnTensorDescriptor_t   tensorDesc,
    size_t                         *size)
        

This function returns the size of the tensor in memory in respect to the given descriptor. This function can be used to know the amount of GPU memory to be allocated to hold that tensor.

Parameters

tensorDesc

Input. Handle to a previously initialized tensor descriptor.

size

Output. Size in bytes needed to hold the tensor in GPU memory.

Returns

CUDNN_STATUS_SUCCESS

The results were returned successfully.

3.2.62. cudnnGetTensorTransformDescriptor()

            

            
cudnnStatus_t cudnnGetTensorTransformDescriptor(
	cudnnTensorTransformDescriptor_t transformDesc,
	uint32_t nbDimsRequested,
	cudnnTensorFormat_t *destFormat,
	int32_t padBeforeA[],
	int32_t padAfterA[],
	uint32_t foldA[],
	cudnnFoldingDirection_t *direction);
        

This function returns the values stored in a previously initialized tensor transform descriptor.

Parameters

transformDesc

Input. A previously initialized tensor transform descriptor.

nbDimsRequested

Input. The number of dimensions to consider. For more information, see the Tensor Descriptor section in the cuDNN Developer Guide.

destFormat

Output. The transform format that will be returned.

padBeforeA[]

Output. An array filled with the amount of padding to add before each dimension. The dimension of this padBeforeA[] parameter is equal to nbDimsRequested.

padAfterA[]

Output. An array filled with the amount of padding to add after each dimension. The dimension of this padBeforeA[] parameter is equal to nbDimsRequested.

foldA[]

Output. An array that was filled with the folding parameters for each spatial dimension. The dimension of this foldA[] array is nbDimsRequested-2.

direction

Output. The setting that selects folding or unfolding. For more information, see cudnnFoldingDirection_t.

Returns

CUDNN_STATUS_SUCCESS

The results were obtained successfully.

CUDNN_STATUS_BAD_PARAM

If transformDesc is NULL or if nbDimsRequested is less than 3 or greater than CUDNN_DIM_MAX.

3.2.63. cudnnGetVersion()

            

            
size_t cudnnGetVersion()
        

This function returns the version number of the cuDNN library. It returns the CUDNN_VERSION defined present in the cudnn.h header file. Starting with release R2, the routine can be used to identify dynamically the current cuDNN library used by the application. The defined CUDNN_VERSION can be used to have the same application linked against different cuDNN versions using conditional compilation statements.

3.2.64. cudnnInitTransformDest()

            

            
cudnnStatus_t cudnnInitTransformDest(
	const cudnnTensorTransformDescriptor_t transformDesc,
	const cudnnTensorDescriptor_t srcDesc,
	cudnnTensorDescriptor_t destDesc,
	size_t *destSizeInBytes);
        

This function initializes and returns a destination tensor descriptor destDesc for tensor transform operations. The initialization is done with the desired parameters described in the transform descriptor cudnnTensorDescriptor_t.

Parameters

transformDesc

Input. Handle to a previously initialized tensor transform descriptor.

srcDesc

Input. Handle to a previously initialized tensor descriptor.

destDesc

Output. Handle of the tensor descriptor that will be initialized and returned.

destSizeInBytes

Output. A pointer to hold the size, in bytes, of the new tensor.

Returns

CUDNN_STATUS_SUCCESS

The tensor descriptor was initialized successfully.

CUDNN_STATUS_BAD_PARAM

If either srcDesc or destDesc is NULL, or if the tensor descriptor’s nbDims is incorrect. For more information, see the Tensor Descriptor section in the cuDNN Developer Guide.

CUDNN_STATUS_NOT_SUPPORTED

If the provided configuration is not 4D.

CUDNN_STATUS_EXECUTION_FAILED

Function failed to launch on the GPU.

3.2.65. cudnnLRNCrossChannelForward()

            

            
cudnnStatus_t cudnnLRNCrossChannelForward(
    cudnnHandle_t                    handle,
    cudnnLRNDescriptor_t             normDesc,
    cudnnLRNMode_t                   lrnMode,
    const void                      *alpha,
    const cudnnTensorDescriptor_t    xDesc,
    const void                      *x,
    const void                      *beta,
    const cudnnTensorDescriptor_t    yDesc,
    void                            *y)
        

This function performs the forward LRN layer computation.

Parameters

handle

Input. Handle to a previously created cuDNN library descriptor.

normDesc

Input. Handle to a previously initialized LRN parameter descriptor.

lrnMode

Input. LRN layer mode of operation. Currently only CUDNN_LRN_CROSS_CHANNEL_DIM1 is implemented. Normalization is performed along the tensor's dimA[1].

alpha, beta

Input. Pointers to scaling factors (in host memory) used to blend the layer output value with prior value in the destination tensor as follows:

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dstValue = alpha[0]*resultValue + beta[0]*priorDstValue
        

For more information, see Scaling Parameters in the cuDNN Developer Guide.

xDesc, yDesc

Input. Tensor descriptor objects for the input and output tensors.

x

Input. Input tensor data pointer in device memory.

y

Output. Output tensor data pointer in device memory.

Returns

CUDNN_STATUS_SUCCESS

The computation was performed successfully.

CUDNN_STATUS_BAD_PARAM

At least one of the following conditions are met:

• One of the tensor pointers x, y is NULL.
• Number of input tensor dimensions is 2 or less.
• LRN descriptor parameters are outside of their valid ranges.
• One of the tensor parameters is 5D but is not in NCDHW DHW-packed format.

CUDNN_STATUS_NOT_SUPPORTED

The function does not support the provided configuration. See the following for some examples of non-supported configurations:

• Any of the input tensor datatypes is not the same as any of the output tensor datatype.
• x and y tensor dimensions mismatch.
• Any tensor parameters strides are negative.

3.2.66. cudnnNormalizationForwardInference()

            

            
cudnnStatus_t
cudnnNormalizationForwardInference(cudnnHandle_t handle,
                                   cudnnNormMode_t mode,
                   	            cudnnNormOps_t normOps,
                                   cudnnNormAlgo_t algo,
                         	      const void *alpha,
                               	const void *beta, 
                               	const cudnnTensorDescriptor_t xDesc,
                        	       const void *x,
                               	const cudnnTensorDescriptor_t normScaleBiasDesc,
                               	const void *normScale,
                               	const void *normBias,
                 	              const cudnnTensorDescriptor_t normMeanVarDesc,
                               	const void *estimatedMean,
                               	const void *estimatedVariance,
                             	  const cudnnTensorDescriptor_t zDesc,
                               	const void *z,
                                   cudnnActivationDescriptor_t activationDesc,
                               	const cudnnTensorDescriptor_t yDesc,
            	                   void *y,
                               	double epsilon,
                               	int groupCnt);
        

This function performs the forward normalization layer computation for the inference phase. Per-channel normalization layer is based on the paper Batch Normalization: Accelerating Deep Network Training by Reducing Internal Covariate Shift, S. Ioffe, C. Szegedy, 2015.

Parameters

handle

Input. Handle to a previously created cuDNN library descriptor. For more information, see cudnnHandle_t.

mode

Input. Mode of operation (per-channel or per-activation). For more information, see cudnnNormMode_t.

normOps

Input. Mode of post-operative. Currently, CUDNN_NORM_OPS_NORM_ACTIVATION and CUDNN_NORM_OPS_NORM_ADD_ACTIVATION are not supported.

algo

Input. Algorithm to be performed. For more information, see cudnnNormAlgo_t.

alpha, beta

Inputs. Pointers to scaling factors (in host memory) used to blend the layer output value with prior value in the destination tensor as follows:

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dstValue = alpha[0]*resultValue + beta[0]*priorDstValue
        

For more information, see Scaling Parameters in the cuDNN Developer Guide.

xDesc, yDesc

Input. Handles to the previously initialized tensor descriptors.

*x

Input. Data pointer to GPU memory associated with the tensor descriptor xDesc, for the layer’s x input data.

*y

Output. Data pointer to GPU memory associated with the tensor descriptor yDesc, for the y output of the normalization layer.

zDesc, *z

Input. Tensor descriptors and pointers in device memory for residual addition to the result of the normalization operation, prior to the activation. zDesc and *z are optional and are only used when normOps is CUDNN_NORM_OPS_NORM_ADD_ACTIVATION, otherwise users may pass NULL. When in use, z should have exactly the same dimension as x and the final output y. For more information, see cudnnTensorDescriptor_t.

Since normOps is only supported for CUDNN_NORM_OPS_NORM, we can set these to NULL for now.

normScaleBiasDesc, normScale, normBias

Inputs. Tensor descriptors and pointers in device memory for the normalization scale and bias parameters (in the original paper bias is referred to as beta and scale as gamma).

normMeanVarDesc, estimatedMean, estimatedVariance

Inputs. Mean and variance tensors and their tensor descriptors. The estimatedMean and estimatedVariance inputs, accumulated during the training phase from the cudnnNormalizationForwardTraining() call, should be passed as inputs here.

activationDesc

Input. Descriptor for the activation operation. When the normOps input is set to either CUDNN_NORM_OPS_NORM_ACTIVATION or CUDNN_NORM_OPS_NORM_ADD_ACTIVATION then this activation is used, otherwise the user may pass NULL. Since normOps is only supported for CUDNN_NORM_OPS_NORM, we can set these to NULL for now.

epsilon

Input. Epsilon value used in the normalization formula. Its value should be equal to or greater than zero.

groutCnt

Input. Only support 1 for now.

Returns

CUDNN_STATUS_SUCCESS

The computation was performed successfully.

CUDNN_STATUS_NOT_SUPPORTED

The function does not support the provided configuration.

CUDNN_STATUS_BAD_PARAM

At least one of the following conditions are met:

• One of the pointers alpha, beta, x, y, normScale, normBias, estimatedMean, and estimatedInvVariance is NULL.
• The number of xDesc or yDesc tensor descriptor dimensions is not within the range of [4,5] (only 4D and 5D tensors are supported).
• normScaleBiasDesc and normMeanVarDesc dimensions are not 1xCx1x1 for 4D and 1xCx1x1x1 for 5D for per-channel, and are not 1xCxHxW for 4D and 1xCxDxHxW for 5D for per-activation mode.
• epsilon value is less than zero.
• Dimensions or data types mismatch for xDesc and yDesc.

CUDNN_STATUS_NOT_SUPPORTED

A compute or data type other than FLOAT was chosen, or an unknown algorithm type was chosen.

CUDNN_STATUS_EXECUTION_FAILED

The function failed to launch on the GPU.

3.2.67. cudnnOpsInferVersionCheck()

            

            
cudnnStatus_t cudnnOpsInferVersionCheck(void)
        

This function is the first of a series of corresponding functions that check for consistent library versions among DLL files for different modules.

Returns

CUDNN_STATUS_SUCCESS

The version of this DLL file is consistent with cuDNN DLLs on which it depends.

CUDNN_STATUS_VERSION_MISMATCH

The version of this DLL file does not match that of a cuDNN DLLs on which it depends.

3.2.68. cudnnOpTensor()

            

            
cudnnStatus_t cudnnOpTensor(
    cudnnHandle_t                     handle,
    const cudnnOpTensorDescriptor_t   opTensorDesc,
    const void                       *alpha1,
    const cudnnTensorDescriptor_t     aDesc,
    const void                       *A,
    const void                       *alpha2,
    const cudnnTensorDescriptor_t     bDesc,
    const void                       *B,
    const void                       *beta,
    const cudnnTensorDescriptor_t     cDesc,
    void                             *C)
        

This function implements the equation C = op(alpha1[0] * A, alpha2[0] * B) + beta[0] * C, given the tensors A, B, and C and the scaling factors alpha1, alpha2, and beta. The op to use is indicated by the descriptor cudnnOpTensorDescriptor_t, meaning, the type of opTensorDesc. Currently-supported ops are listed by the cudnnOpTensorOp_t enum. The following restrictions on the input and destination tensors apply:

• Each dimension of the input tensor A must match the corresponding dimension of the destination tensor C, and each dimension of the input tensor B must match the corresponding dimension of the destination tensor C or must be equal to 1. In the latter case, the same value from the input tensor B for those dimensions will be used to blend into the C tensor.
• The data types of the input tensors A and B, and the destination tensor C, must satisfy Table 7.

Parameters

handle

Input. Handle to a previously created cuDNN context.

opTensorDesc

Input. Handle to a previously initialized op tensor descriptor.

alpha1, alpha2, beta

Input. Pointers to scaling factors (in host memory) used to blend the source value with prior value in the destination tensor as follows:

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dstValue = alpha[0]*resultValue + beta[0]*priorDstValue
        

For more information, see Scaling Parameters in the cuDNN Developer Guide.

aDesc, bDesc, cDesc

Input. Handle to a previously initialized tensor descriptor.

A, B

Input. Pointer to data of the tensors described by the aDesc and bDesc descriptors, respectively.

C

Input/Output. Pointer to data of the tensor described by the cDesc descriptor.

Returns

CUDNN_STATUS_SUCCESS

The function executed successfully.

CUDNN_STATUS_NOT_SUPPORTED

The function does not support the provided configuration. See the following for some examples of non-supported configurations:

• The dimensions of the bias tensor and the output tensor dimensions are above 5.
• opTensorCompType is not set as stated above.

CUDNN_STATUS_BAD_PARAM

The data type of the destination tensor C is unrecognized, or the restrictions on the input and destination tensors, stated above, are not met.

CUDNN_STATUS_EXECUTION_FAILED

The function failed to launch on the GPU.

3.2.69. cudnnPoolingForward()

            

            
cudnnStatus_t cudnnPoolingForward(
    cudnnHandle_t                    handle,
    const cudnnPoolingDescriptor_t   poolingDesc,
    const void                      *alpha,
    const cudnnTensorDescriptor_t    xDesc,
    const void                      *x,
    const void                      *beta,
    const cudnnTensorDescriptor_t    yDesc,
    void                            *y)
        

This function computes pooling of input values (meaning, the maximum or average of several adjacent values) to produce an output with smaller height and/or width.

Parameters

handle

Input. Handle to a previously created cuDNN context.

poolingDesc

Input. Handle to a previously initialized pooling descriptor.

alpha, beta

Input. Pointers to scaling factors (in host memory) used to blend the computation result with prior value in the output layer as follows:

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dstValue = alpha[0]*resultValue + beta[0]*priorDstValue
        

For more information, see Scaling Parameters in the cuDNN Developer Guide.

xDesc

Input. Handle to the previously initialized input tensor descriptor. Must be of type FLOAT, DOUBLE, HALF or INT8. For more information, see cudnnDataType_t.

x

Input. Data pointer to GPU memory associated with the tensor descriptor xDesc.

yDesc

Input. Handle to the previously initialized output tensor descriptor. Must be of type FLOAT, DOUBLE, HALF or INT8. For more information, see cudnnDataType_t.

y

Output. Data pointer to GPU memory associated with the output tensor descriptor yDesc.

Returns

CUDNN_STATUS_SUCCESS

The function launched successfully.

CUDNN_STATUS_BAD_PARAM

At least one of the following conditions are met:

• The dimensions n, c of the input tensor and output tensors differ.
• The datatype of the input tensor and output tensors differs.

CUDNN_STATUS_NOT_SUPPORTED

The function does not support the provided configuration.

CUDNN_STATUS_EXECUTION_FAILED

The function failed to launch on the GPU.

3.2.70. cudnnQueryRuntimeError()

            

            
cudnnStatus_t cudnnQueryRuntimeError(
    cudnnHandle_t            handle,
    cudnnStatus_t           *rstatus,
    cudnnErrQueryMode_t      mode,
    cudnnRuntimeTag_t       *tag)
        

cuDNN library functions perform extensive input argument checking before launching GPU kernels. The last step is to verify that the GPU kernel actually started. When a kernel fails to start, CUDNN_STATUS_EXECUTION_FAILED is returned by the corresponding API call. Typically, after a GPU kernel starts, no runtime checks are performed by the kernel itself - numerical results are simply written to output buffers.

When the CUDNN_BATCHNORM_SPATIAL_PERSISTENT mode is selected in cudnnBatchNormalizationForwardTraining() or cudnnBatchNormalizationBackward(), the algorithm may encounter numerical overflows where CUDNN_BATCHNORM_SPATIAL performs just fine albeit at a slower speed. The user can invoke cudnnQueryRuntimeError() to make sure numerical overflows did not occur during the kernel execution. Those issues are reported by the kernel that performs computations.

cudnnQueryRuntimeError() can be used in polling and blocking software control flows. There are two polling modes (CUDNN_ERRQUERY_RAWCODE and CUDNN_ERRQUERY_NONBLOCKING) and one blocking mode CUDNN_ERRQUERY_BLOCKING.

CUDNN_ERRQUERY_RAWCODE reads the error storage location regardless of the kernel completion status. The kernel might not even start and the error storage (allocated per cuDNN handle) might be used by an earlier call.

CUDNN_ERRQUERY_NONBLOCKING checks if all tasks in the user stream are completed. The cudnnQueryRuntimeError() function will return immediately and report CUDNN_STATUS_RUNTIME_IN_PROGRESS in rstatus if some tasks in the user stream are pending. Otherwise, the function will copy the remote kernel error code to rstatus.

In the blocking mode (CUDNN_ERRQUERY_BLOCKING), the function waits for all tasks to drain in the user stream before reporting the remote kernel error code. The blocking flavor can be further adjusted by calling cudaSetDeviceFlags with the cudaDeviceScheduleSpin, cudaDeviceScheduleYield, or cudaDeviceScheduleBlockingSync flag.

CUDNN_ERRQUERY_NONBLOCKING and CUDNN_ERRQUERY_BLOCKING modes should not be used when the user stream is changed in the cuDNN handle, meaning, cudnnSetStream() is invoked between functions that report runtime kernel errors and the cudnnQueryRuntimeError() function.

The remote error status reported in rstatus can be set to: CUDNN_STATUS_SUCCESS, CUDNN_STATUS_RUNTIME_IN_PROGRESS, or CUDNN_STATUS_RUNTIME_FP_OVERFLOW. The remote kernel error is automatically cleared by cudnnQueryRuntimeError().

Parameters

handle

Input. Handle to a previously created cuDNN context.

rstatus

Output. Pointer to the user's error code storage.

mode

Input. Remote error query mode.

tag

Input/Output. Currently, this argument should be NULL.

Returns

CUDNN_STATUS_SUCCESS

No errors detected (rstatus holds a valid value).

CUDNN_STATUS_BAD_PARAM

Invalid input argument.

CUDNN_STATUS_INTERNAL_ERROR

A stream blocking synchronization or a non-blocking stream query failed.

CUDNN_STATUS_MAPPING_ERROR

The device cannot access zero-copy memory to report kernel errors.

3.2.71. cudnnReduceTensor()

            

            
cudnnStatus_t cudnnReduceTensor(
    cudnnHandle_t                           handle,
    const cudnnReduceTensorDescriptor_t     reduceTensorDesc,
    void                                   *indices,
    size_t                                  indicesSizeInBytes,
    void                                   *workspace,
    size_t                                  workspaceSizeInBytes,
    const void                             *alpha,
    const cudnnTensorDescriptor_t           aDesc,
    const void                             *A,
    const void                             *beta,
    const cudnnTensorDescriptor_t           cDesc,
    void                                   *C)
        

This function reduces tensor A by implementing the equation C = alpha * reduce op ( A ) + beta * C, given tensors A and C and scaling factors alpha and beta. The reduction op to use is indicated by the descriptor reduceTensorDesc. Currently-supported ops are listed by the cudnnReduceTensorOp_t enum.

Each dimension of the output tensor C must match the corresponding dimension of the input tensor A or must be equal to 1. The dimensions equal to 1 indicate the dimensions of A to be reduced.

The implementation will generate indices for the min and max ops only, as indicated by the cudnnReduceTensorIndices_t enum of the reduceTensorDesc. Requesting indices for the other reduction ops results in an error. The data type of the indices is indicated by the cudnnIndicesType_t enum; currently only the 32-bit (unsigned int) type is supported.

The indices returned by the implementation are not absolute indices but relative to the dimensions being reduced. The indices are also flattened, meaning, not coordinate tuples.

The data types of the tensors A and C must match if of type double. In this case, alpha and beta and the computation enum of reduceTensorDesc are all assumed to be of type double. The HALF and INT8 data types may be mixed with the FLOAT data types. In these cases, the computation enum of reduceTensorDesc is required to be of type FLOAT.