A utility class for folding operations, and unifying duplicated constants generated along the way. More...

#include "mlir/Transforms/FoldUtils.h"

Public Types
enum class	ConstantInsertionResult { Unchanged , Hoisted , Replaced }
	The effect of inserting a known constant on the IR. More...

Public Member Functions
	OperationFolder (MLIRContext ctx, OpBuilder::Listener listener=nullptr)
LogicalResult	tryToFold (Operation op, bool inPlaceUpdate=nullptr, int maxIterations=INT_MAX)
	Tries to perform folding on the given op, including unifying deduplicated constants.
ConstantInsertionResult	insertKnownConstant (Operation *op, Attribute constValue={})
	Tries to fold a pre-existing constant operation.
void	notifyRemoval (Operation *op)
	Notifies that the given constant op should be remove from this OperationFolder's internal bookkeeping.
void	clear ()
	Clear out any constants cached inside of the folder.
Value	getOrCreateConstant (Block block, Dialect dialect, Attribute value, Type type)
	Get or create a constant for use in the specified block.

Detailed Description

A utility class for folding operations, and unifying duplicated constants generated along the way.

Definition at line 33 of file FoldUtils.h.

Member Enumeration Documentation

◆ ConstantInsertionResult

enum class mlir::OperationFolder::ConstantInsertionResult

strong

The effect of inserting a known constant on the IR.

Enumerator
Unchanged	The operation was retained without modifying the IR.
Hoisted	The operation was retained but moved to the insertion point.
Replaced	The operation was replaced with an existing constant and erased.

Definition at line 49 of file FoldUtils.h.

Constructor & Destructor Documentation

◆ OperationFolder()

mlir::OperationFolder::OperationFolder	(	MLIRContext *	ctx,
		OpBuilder::Listener *	listener = nullptr )

inline

Definition at line 35 of file FoldUtils.h.

References mlir::get().

Member Function Documentation

◆ clear()

void OperationFolder::clear ( )

Clear out any constants cached inside of the folder.

Definition at line 205 of file FoldUtils.cpp.

◆ getOrCreateConstant()

Value OperationFolder::getOrCreateConstant	(	Block *	block,
		Dialect *	dialect,
		Attribute	value,
		Type	type )

Get or create a constant for use in the specified block.

Get or create a constant using the given builder.

The constant may be created in a parent block. On success this returns the constant operation, nullptr otherwise.

On success this returns the constant operation, nullptr otherwise.

Definition at line 212 of file FoldUtils.cpp.

References getInsertionRegion(), and mlir::Operation::getResult().

Referenced by replaceWithConstant().

◆ insertKnownConstant()

OperationFolder::ConstantInsertionResult OperationFolder::insertKnownConstant	(	Operation *	op,
		Attribute	constValue = {} )

Tries to fold a pre-existing constant operation.

constValue represents the value of the constant, and can be optionally passed if the value is already known (e.g. if the constant was discovered by m_Constant). This is purely an optimization opportunity for callers that already know the value of the constant. Returns Replaced if an existing constant for op already exists in the folder, in which case op is replaced and erased. Otherwise, op is inserted into the folder (and hoisted if necessary), returning Hoisted if it was moved or Unchanged if the IR was not modified.

Definition at line 114 of file FoldUtils.cpp.

References mlir::Block::front(), mlir::Region::front(), mlir::Operation::getBlock(), mlir::Operation::getDialect(), getInsertionRegion(), mlir::Operation::getResults(), Hoisted, mlir::m_Constant(), mlir::matchPattern(), notifyRemoval(), Replaced, result, mlir::Operation::result_type_begin(), mlir::Operation::setLoc(), and Unchanged.

◆ notifyRemoval()

void OperationFolder::notifyRemoval ( Operation * op )

Notifies that the given constant op should be remove from this OperationFolder's internal bookkeeping.

Note: this method must be called if a constant op is to be deleted externally to this OperationFolder. op must be a constant op.

Definition at line 181 of file FoldUtils.cpp.

References mlir::Operation::getBlock(), getInsertionRegion(), mlir::Operation::getResult(), mlir::Value::getType(), mlir::m_Constant(), and mlir::matchPattern().

Referenced by insertKnownConstant(), and tryToFold().

◆ tryToFold()

LogicalResult OperationFolder::tryToFold	(	Operation *	op,
		bool *	inPlaceUpdate = nullptr,
		int	maxIterations = INT_MAX )

Tries to perform folding on the given op, including unifying deduplicated constants.

If successful, replaces op's uses with folded results, and returns success. If the op was completely folded it is erased. If it is just updated in place, inPlaceUpdate is set to true. On success() and when in-place, the folder is invoked until maxIterations is reached (default INT_MAX).

Definition at line 71 of file FoldUtils.cpp.

References mlir::Block::front(), mlir::Operation::getBlock(), notifyRemoval(), mlir::Operation::setLoc(), success(), and tryToFold().

Referenced by tryToFold().

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

include/mlir/Transforms/FoldUtils.h
lib/Transforms/Utils/FoldUtils.cpp

Public Types

Public Member Functions