sdfg::transformations::LoopTiling Class Reference

Loop tiling (blocking) transformation. More...

#include <sdfg/transformations/loop_tiling.h>

Inheritance diagram for sdfg::transformations::LoopTiling:

Public Member Functions
	LoopTiling (structured_control_flow::StructuredLoop &loop, size_t tile_size, bool simplify_bounds=true)
	Construct a loop tiling transformation.
virtual std::string	name () const override
	Get the name of this transformation.
virtual bool	can_be_applied (builder::StructuredSDFGBuilder &builder, analysis::AnalysisManager &analysis_manager) override
	Check if this transformation can be applied.
virtual void	apply (builder::StructuredSDFGBuilder &builder, analysis::AnalysisManager &analysis_manager) override
	Apply the loop tiling transformation.
virtual void	to_json (nlohmann::json &j) const override
	Serialize this transformation to JSON.
structured_control_flow::StructuredLoop *	inner_loop ()
structured_control_flow::StructuredLoop *	outer_loop ()
Public Member Functions inherited from sdfg::transformations::Transformation
virtual	~Transformation ()=default
virtual void	set_report (PassReportConsumer *report)
	Set the report consumer for transformation feedback.
virtual bool	try_apply (builder::StructuredSDFGBuilder &builder, analysis::AnalysisManager &analysis_manager)
	Attempt to apply the transformation if possible.

Static Public Member Functions
static LoopTiling	from_json (builder::StructuredSDFGBuilder &builder, const nlohmann::json &j)
	Deserialize a loop tiling transformation from JSON.

Protected Member Functions
bool	reduction_buffers_supported (builder::StructuredSDFGBuilder &builder, analysis::AnalysisManager &analysis_manager, const std::vector< size_t > &tile_sizes) const
	Check reduction footprints using symbolic tile domains without changing the graph.

Static Protected Member Functions
static structured_control_flow::StructuredLoop &	tile_loop (builder::StructuredSDFGBuilder &builder, structured_control_flow::StructuredLoop &loop, size_t tile_size, bool simplify_bounds=true)
	Tile a single loop into an outer tile loop and an inner element loop.

Protected Attributes
structured_control_flow::StructuredLoop &	loop_
size_t	tile_size_
bool	simplify_bounds_ = true
bool	applied_ = false
structured_control_flow::StructuredLoop *	inner_loop_ = nullptr
structured_control_flow::StructuredLoop *	outer_loop_ = nullptr
Protected Attributes inherited from sdfg::transformations::Transformation
PassReportConsumer *	report_ = nullptr

Detailed Description

Loop tiling (blocking) transformation.

This transformation splits a loop into two nested loops: an outer loop that iterates over tiles and an inner loop that iterates within each tile. Loop tiling improves data locality by ensuring that data accessed within a tile fits in cache.

Note

The loop must be contiguous (analyzed via LoopAnalysis)

The tile size must be greater than 1

Constructor & Destructor Documentation

LoopTiling()

sdfg::transformations::LoopTiling::LoopTiling	(	structured_control_flow::StructuredLoop &	loop,
		size_t	tile_size,
		bool	simplify_bounds = true )

Construct a loop tiling transformation.

Parameters

loop	The loop to be tiled
tile_size	The size of each tile (must be > 1)
simplify_bounds	Drop the redundant inner bound for perfectly dividing tiles (see tile_loop)

Member Function Documentation

apply()

virtual void sdfg::transformations::LoopTiling::apply ( builder::StructuredSDFGBuilder & builder, analysis::AnalysisManager & analysis_manager )

overridevirtual

Apply the loop tiling transformation.

Parameters

builder	The SDFG builder
analysis_manager	The analysis manager

Implements sdfg::transformations::Transformation.

Reimplemented in sdfg::transformations::MultiLevelTiling.

can_be_applied()

virtual bool sdfg::transformations::LoopTiling::can_be_applied ( builder::StructuredSDFGBuilder & builder, analysis::AnalysisManager & analysis_manager )

overridevirtual

Check if this transformation can be applied.

Parameters

builder	The SDFG builder
analysis_manager	The analysis manager

Returns

true if the transformation can be applied safely

Implements sdfg::transformations::Transformation.

Reimplemented in sdfg::transformations::MultiLevelTiling.

from_json()

LoopTiling sdfg::transformations::LoopTiling::from_json ( builder::StructuredSDFGBuilder & builder, const nlohmann::json & j )

static

Deserialize a loop tiling transformation from JSON.

Parameters

builder	The SDFG builder
j	JSON description of the transformation

Returns

The deserialized transformation

inner_loop()

structured_control_flow::StructuredLoop * sdfg::transformations::LoopTiling::inner_loop

(

)

name()

virtual std::string sdfg::transformations::LoopTiling::name ( ) const

overridevirtual

Get the name of this transformation.

Returns

"LoopTiling"

Implements sdfg::transformations::Transformation.

Reimplemented in sdfg::transformations::MultiLevelTiling.

outer_loop()

structured_control_flow::StructuredLoop * sdfg::transformations::LoopTiling::outer_loop

(

)

reduction_buffers_supported()

bool sdfg::transformations::LoopTiling::reduction_buffers_supported ( builder::StructuredSDFGBuilder & builder, analysis::AnalysisManager & analysis_manager, const std::vector< size_t > & tile_sizes ) const

protected

Check reduction footprints using symbolic tile domains without changing the graph.

Parameters

builder	The builder for the unchanged original SDFG
analysis_manager	The analysis manager for the current graph
tile_sizes	Tile sizes in application order, each applied to the inner loop

Returns

true if affected reductions are unmaterialized and their proposed footprints are exact

tile_loop()

structured_control_flow::StructuredLoop & sdfg::transformations::LoopTiling::tile_loop ( builder::StructuredSDFGBuilder & builder, structured_control_flow::StructuredLoop & loop, size_t tile_size, bool simplify_bounds = true )

staticprotected

Tile a single loop into an outer tile loop and an inner element loop.

Splits loop in place: loop becomes the inner (element) loop and a new outer loop iterating over tiles is created before it. Map/Reduce loops preserve their schedule/reductions on the outer loop, while a tiled Map's inner loop is converted to a sequential schedule to avoid repeated GPU dimensions.

Parameters

builder	The SDFG builder
loop	The loop to tile (becomes the inner loop)
tile_size	The size of each tile (must be > 1)
simplify_bounds	Drop the redundant original bound on the inner loop when the tile evenly divides the (constant) trip count, yielding a clean constant-trip tile that unrolls/vectorizes and leaves no redundant guards for later peeling.

Returns

The newly created outer tile loop

to_json()

virtual void sdfg::transformations::LoopTiling::to_json ( nlohmann::json & j ) const

overridevirtual

Serialize this transformation to JSON.

Parameters

j	JSON object to populate

Implements sdfg::transformations::Transformation.

Reimplemented in sdfg::transformations::MultiLevelTiling.

Member Data Documentation

applied_

bool sdfg::transformations::LoopTiling::applied_ = false

protected

inner_loop_

structured_control_flow::StructuredLoop* sdfg::transformations::LoopTiling::inner_loop_ = nullptr

protected

loop_

structured_control_flow::StructuredLoop& sdfg::transformations::LoopTiling::loop_

protected

outer_loop_

structured_control_flow::StructuredLoop* sdfg::transformations::LoopTiling::outer_loop_ = nullptr

protected

simplify_bounds_

bool sdfg::transformations::LoopTiling::simplify_bounds_ = true

protected

tile_size_

size_t sdfg::transformations::LoopTiling::tile_size_

protected

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

• opt/include/sdfg/transformations/loop_tiling.h