DML_BATCH_NORMALIZATION_GRAD_OPERATOR_DESC structure (directml.h)

Computes backpropagation gradients for batch normalization. DML_BATCH_NORMALIZATION_GRAD_OPERATOR_DESC performs multiple computations, which are detailed in the separate output descriptions.

OutputScaleGradientTensor and OutputBiasGradientTensor are computed using sums across the set of dimensions for which MeanTensor, ScaleTensor and VarianceTensor sizes equal one.

Syntax

struct DML_BATCH_NORMALIZATION_GRAD_OPERATOR_DESC {
  const DML_TENSOR_DESC *InputTensor;
  const DML_TENSOR_DESC *InputGradientTensor;
  const DML_TENSOR_DESC *MeanTensor;
  const DML_TENSOR_DESC *VarianceTensor;
  const DML_TENSOR_DESC *ScaleTensor;
  const DML_TENSOR_DESC *OutputGradientTensor;
  const DML_TENSOR_DESC *OutputScaleGradientTensor;
  const DML_TENSOR_DESC *OutputBiasGradientTensor;
  FLOAT                 Epsilon;
};

Members

InputTensor

Type: const DML_TENSOR_DESC*

A tensor containing the input data. This is typically the same tensor that was provided as the InputTensor to DML_BATCH_NORMALIZATION_OPERATOR_DESC in the forward pass.

InputGradientTensor

Type: const DML_TENSOR_DESC*

The incoming gradient tensor. This is typically obtained from the output of backpropagation of a preceding layer.

MeanTensor

Type: const DML_TENSOR_DESC*

A tensor containing the mean data. This is typically the same tensor that was provided as the MeanTensor to DML_BATCH_NORMALIZATION_OPERATOR_DESC in the forward pass.

VarianceTensor

Type: const DML_TENSOR_DESC*

A tensor containing the variance data. This is typically the same tensor that was provided as the VarianceTensor to DML_OPERATOR_BATCH_NORMALIZATION in the forward pass.

ScaleTensor

Type: const DML_TENSOR_DESC*

A tensor containing the scale data. This is typically the same tensor that was provided as the ScaleTensor to DML_BATCH_NORMALIZATION_OPERATOR_DESC in the forward pass.

OutputGradientTensor

Type: const DML_TENSOR_DESC*

For every corresponding value in the inputs, OutputGradient = InputGradient * (Scale / sqrt(Variance + Epsilon)).

OutputScaleGradientTensor

Type: const DML_TENSOR_DESC*

The following computation is done or every corresponding value in the inputs.

OutputScaleGradient = sum(InputGradient * (Input - Mean) / sqrt(Variance + Epsilon))

OutputBiasGradientTensor

Type: const DML_TENSOR_DESC*

The following computation is done or every corresponding value in the inputs.

OutputBiasGradient = sum(InputGradient)

Epsilon

Type: FLOAT

A small value added to the variance to avoid zero.

Remarks

Availability

This operator was introduced in DML_FEATURE_LEVEL_3_1.

Tensor constraints

• InputGradientTensor, InputTensor, MeanTensor, OutputBiasGradientTensor, OutputGradientTensor, OutputScaleGradientTensor, ScaleTensor, and VarianceTensor must have the same DataType and DimensionCount.
• MeanTensor, OutputBiasGradientTensor, OutputScaleGradientTensor, ScaleTensor, and VarianceTensor must have the same Sizes.
• InputGradientTensor, InputTensor, and OutputGradientTensor must have the same Sizes.

Tensor support

Requirements