A primitive to perform layer normalization. More...

Classes
struct	dnnl::layer_normalization_forward
	Layer normalization forward propagation primitive. More...

struct	dnnl::layer_normalization_backward
	Layer normalization backward propagation primitive. More...

struct	dnnl_layer_normalization_desc_t
	A descriptor of a Layer Normalization operation. More...

Functions
dnnl_status_t DNNL_API	dnnl_layer_normalization_forward_desc_init (dnnl_layer_normalization_desc_t lnrm_desc, dnnl_prop_kind_t prop_kind, const dnnl_memory_desc_t data_desc, const dnnl_memory_desc_t *stat_desc, float epsilon, unsigned flags)
	Initializes a descriptor for layer normalization forward propagation primitive. More...

dnnl_status_t DNNL_API	dnnl_layer_normalization_backward_desc_init (dnnl_layer_normalization_desc_t lnrm_desc, dnnl_prop_kind_t prop_kind, const dnnl_memory_desc_t diff_data_desc, const dnnl_memory_desc_t data_desc, const dnnl_memory_desc_t stat_desc, float epsilon, unsigned flags)
	Initializes a descriptor for a layer normalization backward propagation primitive. More...

Detailed Description

A primitive to perform layer normalization.

Normalization is performed within the last logical dimension of data tensor.

Both forward and backward propagation primitives support in-place operation; that is, src and dst can refer to the same memory for forward propagation, and diff_dst and diff_src can refer to the same memory for backward propagation.

The layer normalization primitives computations can be controlled by specifying different dnnl::normalization_flags values. For example, layer normalization forward propagation can be configured to either compute the mean and variance or take them as arguments. It can either perform scaling and shifting using gamma and beta parameters or not. Optionally, it can also perform a fused ReLU, which in case of training would also require a workspace.

See also: Layer Normalization in developer guide

Function Documentation

◆ dnnl_layer_normalization_forward_desc_init()

dnnl_status_t DNNL_API dnnl_layer_normalization_forward_desc_init	(	dnnl_layer_normalization_desc_t *	lnrm_desc,
		dnnl_prop_kind_t	prop_kind,
		const dnnl_memory_desc_t *	data_desc,
		const dnnl_memory_desc_t *	stat_desc,
		float	epsilon,
		unsigned	flags
	)

Initializes a descriptor for layer normalization forward propagation primitive.

Note: In-place operation is supported: the dst can refer to the same memory as the src.

Inputs:

src (dnnl_query_src_md, 0)
mean (dnnl_query_src_md, 1), if dnnl_use_global_stats bit-flag is set in flags
variance (dnnl_query_src_md, 2), if dnnl_use_global_stats bit-flag is set in flags
scale_and_shift (dnnl_query_weights_md, 0), if dnnl_use_scaleshift bit-flag is set in flags

Outputs:

dst (dnnl_query_dst_md, 0)
mean (dnnl_query_dst_md, 1), if dnnl_use_global_stats bit-flag is not set in flags and prop_kind = dnnl_forward_training
variance (dnnl_query_dst_md, 2), if dnnl_use_global_stats bit-flag is not set in flags and prop_kind = dnnl_forward_training

Parameters

lnrm_desc	Output descriptor for layer normalization primitive.
prop_kind	Propagation kind. Possible values are dnnl_forward_training and dnnl_forward_inference.
data_desc	Source and destination memory descriptor.
stat_desc	Memory descriptor for mean and variance. If this parameter is NULL, a zero memory descriptor, or a memory descriptor with format_kind set to dnnl_format_kind_undef, then the memory descriptor for stats is derived from `data_desc` by removing the last dimension.
epsilon	Layer normalization epsilon parameter.
flags	Layer normalization flags (dnnl_normalization_flags_t).

Returns: dnnl_success on success and a status describing the error otherwise.

◆ dnnl_layer_normalization_backward_desc_init()

dnnl_status_t DNNL_API dnnl_layer_normalization_backward_desc_init	(	dnnl_layer_normalization_desc_t *	lnrm_desc,
		dnnl_prop_kind_t	prop_kind,
		const dnnl_memory_desc_t *	diff_data_desc,
		const dnnl_memory_desc_t *	data_desc,
		const dnnl_memory_desc_t *	stat_desc,
		float	epsilon,
		unsigned	flags
	)

Initializes a descriptor for a layer normalization backward propagation primitive.

Note: In-place operation is supported: the diff_dst can refer to the same memory as the diff_src.