CPU implementation of Softmax using abstract TensorDataType API. More...

Inheritance diagram for Mila::Dnn::Compute::CpuSoftmaxOp:

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Collaboration diagram for Mila::Dnn::Compute::CpuSoftmaxOp:

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Public Types
using	CpuExecutionContext = ExecutionContext<DeviceType::Cpu>
using	MR = CpuMemoryResource
using	TensorType = Tensor<TensorDataType::FP32, MR>
using	UnaryOperationBase = UnaryOperation<DeviceType::Cpu, TensorDataType::FP32>
Public Types inherited from Mila::Dnn::Compute::UnaryOperation< DeviceType::Cpu, TensorDataType::FP32 >
using	MR
using	TensorInputType
using	TensorOutputType
Public Types inherited from Mila::Dnn::Compute::Operation< TDeviceType, TInput >
using	DataTypeTraits

Public Member Functions
	CpuSoftmaxOp (IExecutionContext *context, const SoftmaxConfig &config)
void	backward (const ITensor &input, const ITensor &output_grad, ITensor &input_grad) const override
	Backward pass - HOT PATH, pure dispatch to CPU kernel.
void	build (const BuildContext &config) override
	Build the operation for a concrete input shape.
void	forward (const ITensor &input, ITensor &output) const override
	Forward pass - HOT PATH, pure dispatch to CPU kernel.
const SoftmaxConfig &	getConfig () const
std::string	getName () const override
	Human-readable operation name.
OperationType	getOperationType () const override
	Operation type identifier.
void	setParameters (ITensor weight, ITensor bias) override
	Set parameter tensor references (no-op for Softmax - stateless operation).
Public Member Functions inherited from Mila::Dnn::Compute::UnaryOperation< DeviceType::Cpu, TensorDataType::FP32 >
virtual	~UnaryOperation ()=default
Public Member Functions inherited from Mila::Dnn::Compute::Operation< TDeviceType, TInput >
virtual	~Operation ()=default
virtual void	clearGradients () noexcept
	Clear any cached gradient pointers held by the operation.
virtual TensorDataType	getDataType () const
	Tensor data type for this operation.
virtual DeviceType	getDeviceType () const
	Device type for this operation.
virtual std::size_t	getStateMemorySize () const
	Returns the number of bytes of state memory allocated by this operation.
virtual bool	isBuilt () const
	Whether build() completed successfully for a concrete input shape.
virtual bool	isEvalMode () const
	Query whether operation is configured for training.
virtual void	setGradients (ITensor weight_grad, ITensor bias_grad)
	Bind module-owned gradient tensors to the operation.
virtual void	setTrainingMode (TrainingMode training_mode)
	Configure operation training-mode behavior.

Private Attributes
int64_t	cached_axis_ { -1 }
int64_t	cached_dim_size_ { 0 }
int64_t	cached_inner_size_ { 0 }
int64_t	cached_outer_size_ { 0 }
SoftmaxConfig	config_
IExecutionContext *	context_
bool	enable_omp_ { false }

Additional Inherited Members
Static Public Attributes inherited from Mila::Dnn::Compute::Operation< TDeviceType, TInput >
static constexpr TensorDataType	data_type
static constexpr DeviceType	device_type
Static Protected Member Functions inherited from Mila::Dnn::Compute::UnaryOperation< DeviceType::Cpu, TensorDataType::FP32 >
static const TensorInputType &	asInputTensor (const ITensor &t)
static TensorOutputType &	asOutputTensor (ITensor &t)
Protected Attributes inherited from Mila::Dnn::Compute::Operation< TDeviceType, TInput >
bool	is_built_
TrainingMode	training_mode_

Detailed Description

CPU implementation of Softmax using abstract TensorDataType API.

Template parameter TPrecision selects the abstract tensor precision (e.g. FP32). float is the corresponding CPU host representation for that precision.

Design philosophy:

Two-phase initialization: build() does all setup, forward()/backward() are pure dispatch
Softmax has no trainable parameters (stateless operation)
All dimension computation happens once in build()
Forward/backward are hot-path methods with minimal overhead
Uses numerically-stable softmax: exp(x - max(x))

Member Typedef Documentation

◆ CpuExecutionContext

using Mila::Dnn::Compute::CpuSoftmaxOp::CpuExecutionContext = ExecutionContext<DeviceType::Cpu>

◆ MR

using Mila::Dnn::Compute::CpuSoftmaxOp::MR = CpuMemoryResource

◆ TensorType

using Mila::Dnn::Compute::CpuSoftmaxOp::TensorType = Tensor<TensorDataType::FP32, MR>

◆ UnaryOperationBase

using Mila::Dnn::Compute::CpuSoftmaxOp::UnaryOperationBase = UnaryOperation<DeviceType::Cpu, TensorDataType::FP32>

Constructor & Destructor Documentation

◆ CpuSoftmaxOp()

Mila::Dnn::Compute::CpuSoftmaxOp::CpuSoftmaxOp	(	IExecutionContext *	context,
		const SoftmaxConfig &	config )

inline

Member Function Documentation

◆ backward()

void Mila::Dnn::Compute::CpuSoftmaxOp::backward	(	const ITensor &	input,
		const ITensor &	output_grad,
		ITensor &	input_grad ) const

inlineoverridevirtual

Backward pass - HOT PATH, pure dispatch to CPU kernel.

Similar to forward(), this method does minimal work and dispatches directly to the backward kernel using cached dimensions from build().

Algorithm: dX = Y * (dY - dot(Y, dY)) where Y is the softmax output (probabilities) and dY is the gradient.

Implements Mila::Dnn::Compute::UnaryOperation< DeviceType::Cpu, TensorDataType::FP32 >.

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◆ build()

void Mila::Dnn::Compute::CpuSoftmaxOp::build ( const BuildContext & config )

inlineoverridevirtual

Build the operation for a concrete input shape.

This is the COLD PATH where all setup, validation, and computation happens ONCE. After build() completes, forward() and backward() become pure dispatch methods.

Responsibilities:

Validate input shape compatibility
Compute and cache normalized axis
Compute and cache dimension sizes (outer, dim, inner)
Cache OMP parallelization threshold

After build(), the operation is ready for zero-overhead forward/backward dispatch.

Reimplemented from Mila::Dnn::Compute::Operation< TDeviceType, TInput >.

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◆ forward()

void Mila::Dnn::Compute::CpuSoftmaxOp::forward	(	const ITensor &	input,
		ITensor &	output ) const

inlineoverridevirtual

Forward pass - HOT PATH, pure dispatch to CPU kernel.

All setup, validation, and dimension computation was done in build(). This method extracts raw pointers and dispatches directly to the numerically-stable softmax kernel using pre-computed cached dimensions.

Algorithm: softmax(x) = exp(x - max(x)) / sum(exp(x - max(x))) Zero redundant work - maximum performance.

Implements Mila::Dnn::Compute::UnaryOperation< DeviceType::Cpu, TensorDataType::FP32 >.

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◆ getConfig()

const SoftmaxConfig & Mila::Dnn::Compute::CpuSoftmaxOp::getConfig ( ) const

inline

◆ getName()

std::string Mila::Dnn::Compute::CpuSoftmaxOp::getName ( ) const

inlineoverridevirtual

Human-readable operation name.

Implements Mila::Dnn::Compute::Operation< TDeviceType, TInput >.

◆ getOperationType()

OperationType Mila::Dnn::Compute::CpuSoftmaxOp::getOperationType ( ) const

inlineoverridevirtual

Operation type identifier.

Implements Mila::Dnn::Compute::Operation< TDeviceType, TInput >.

◆ setParameters()

void Mila::Dnn::Compute::CpuSoftmaxOp::setParameters	(	ITensor *	weight,
		ITensor *	bias )

inlineoverridevirtual

Set parameter tensor references (no-op for Softmax - stateless operation).

Softmax has no trainable parameters, so this method validates that the inputs are null and does nothing else.

Reimplemented from Mila::Dnn::Compute::Operation< TDeviceType, TInput >.

Member Data Documentation

◆ cached_axis_

int64_t Mila::Dnn::Compute::CpuSoftmaxOp::cached_axis_ { -1 }

private

◆ cached_dim_size_

int64_t Mila::Dnn::Compute::CpuSoftmaxOp::cached_dim_size_ { 0 }

private

◆ cached_inner_size_

int64_t Mila::Dnn::Compute::CpuSoftmaxOp::cached_inner_size_ { 0 }

private

◆ cached_outer_size_

int64_t Mila::Dnn::Compute::CpuSoftmaxOp::cached_outer_size_ { 0 }

private

◆ config_

SoftmaxConfig Mila::Dnn::Compute::CpuSoftmaxOp::config_

private

◆ context_

IExecutionContext* Mila::Dnn::Compute::CpuSoftmaxOp::context_

private

◆ enable_omp_

bool Mila::Dnn::Compute::CpuSoftmaxOp::enable_omp_ { false }

private

The documentation for this class was generated from the following file:

/__w/Mila/Mila/Mila/Src/Dnn/Compute/Devices/Cpu/Operations/CpuSoftmaxOp.ixx

Public Types

Public Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Member Typedef Documentation

◆ CpuExecutionContext

◆ MR

◆ TensorType

◆ UnaryOperationBase

Constructor & Destructor Documentation

◆ CpuSoftmaxOp()

Member Function Documentation

◆ backward()

◆ build()

◆ forward()

◆ getConfig()

◆ getName()

◆ getOperationType()

◆ setParameters()

Member Data Documentation

◆ cached_axis_

◆ cached_dim_size_

◆ cached_inner_size_

◆ cached_outer_size_

◆ config_

◆ context_

◆ enable_omp_