circt::PassReduction Struct Reference

A reduction pattern that applies an mlir::Pass. More...

#include <Reduction.h>

Inheritance diagram for circt::PassReduction:

Collaboration diagram for circt::PassReduction:

Public Member Functions
	PassReduction (MLIRContext *context, std::unique_ptr< Pass > pass, bool canIncreaseSize=false, bool oneShot=false)
uint64_t	match (Operation *op) override
	Check if the reduction can apply to a specific operation.
LogicalResult	rewrite (Operation *op) override
	Apply the reduction to a specific operation.
std::string	getName () const override
	Return a human-readable name for this reduction pattern.
bool	acceptSizeIncrease () const override
	Return true if the tool should accept the transformation this reduction performs on the module even if the overall size of the output increases.
bool	isOneShot () const override
	Return true if the tool should not try to reapply this reduction after it has been successful.
Public Member Functions inherited from circt::Reduction
virtual	~Reduction ()
virtual void	beforeReduction (mlir::ModuleOp)
	Called before the reduction is applied to a new subset of operations.
virtual void	afterReduction (mlir::ModuleOp)
	Called after the reduction has been applied to a subset of operations.
virtual void	matches (Operation *op, llvm::function_ref< void(uint64_t, uint64_t)> addMatch)
	Collect all ways how this reduction can apply to a specific operation.
virtual LogicalResult	rewriteMatches (Operation *op, ArrayRef< uint64_t > matches)
	Apply a set of matches of this reduction to a specific operation.
void	notifyOpErased (Operation *op)

Protected Attributes
MLIRContext *const	context
std::unique_ptr< mlir::PassManager >	pm
StringRef	passName
bool	canIncreaseSize
bool	oneShot

Additional Inherited Members
Public Attributes inherited from circt::Reduction
std::function< void(Operation *)>	notifyOpErasedCallback = nullptr
	An optional callback for reductions to communicate removal of operations.

Detailed Description

A reduction pattern that applies an mlir::Pass.

Definition at line 123 of file Reduction.h.

Constructor & Destructor Documentation

PassReduction()

PassReduction::PassReduction	(	MLIRContext *	context,
		std::unique_ptr< Pass >	pass,
		bool	canIncreaseSize = false,
		bool	oneShot = false
	)

Definition at line 33 of file Reduction.cpp.

References context, passName, and pm.

Member Function Documentation

acceptSizeIncrease()

bool circt::PassReduction::acceptSizeIncrease ( ) const

inlineoverridevirtual

Return true if the tool should accept the transformation this reduction performs on the module even if the overall size of the output increases.

This can be handy for patterns that reduce the complexity of the IR at the cost of some verbosity.

Reimplemented from circt::Reduction.

Definition at line 129 of file Reduction.h.

References canIncreaseSize.

getName()

std::string PassReduction::getName ( ) const

overridevirtual

Return a human-readable name for this reduction pattern.

Implements circt::Reduction.

Definition at line 60 of file Reduction.cpp.

References passName.

isOneShot()

bool circt::PassReduction::isOneShot ( ) const

inlineoverridevirtual

Return true if the tool should not try to reapply this reduction after it has been successful.

This is useful for reductions whose match() function keeps returning true even after the reduction has reached a fixed-point and no longer performs any change. An example of this are reductions that apply a lowering pass which always applies but may leave the input unmodified.

This is mainly useful in conjunction with returning true from acceptSizeIncrease(). For reductions that don't accept an increase, the module size has to decrease for them to be considered useful, which prevents the tool from getting stuck at a local point where the reduction applies but produces no change in the input. However, reductions that do accept a size increase can get stuck in this local fixed-point as they keep applying to the same operations and the tool keeps accepting the unmodified input as an improvement.

Reimplemented from circt::Reduction.

Definition at line 130 of file Reduction.h.

References oneShot.

match()

uint64_t PassReduction::match ( Operation *  op )

overridevirtual

Check if the reduction can apply to a specific operation.

Returns a benefit measure where a higher number means that applying the pattern leads to a bigger reduction and zero means that the patten does not match and thus cannot be applied at all.

Reimplemented from circt::Reduction.

Definition at line 54 of file Reduction.cpp.

References context, and pm.

rewrite()

LogicalResult PassReduction::rewrite ( Operation *  op )

overridevirtual

Apply the reduction to a specific operation.

If the returned result indicates that the application failed, the resulting module is treated the same as if the tester marked it as uninteresting.

Reimplemented from circt::Reduction.

Definition at line 58 of file Reduction.cpp.

References pm.

Member Data Documentation

canIncreaseSize

bool circt::PassReduction::canIncreaseSize

protected

Definition at line 136 of file Reduction.h.

Referenced by acceptSizeIncrease().

context

MLIRContext* const circt::PassReduction::context

protected

Definition at line 133 of file Reduction.h.

Referenced by match(), and PassReduction().

oneShot

bool circt::PassReduction::oneShot

protected

Definition at line 137 of file Reduction.h.

Referenced by isOneShot().

passName

StringRef circt::PassReduction::passName

protected

Definition at line 135 of file Reduction.h.

Referenced by getName(), and PassReduction().

pm

std::unique_ptr<mlir::PassManager> circt::PassReduction::pm

protected

Definition at line 134 of file Reduction.h.

Referenced by match(), PassReduction(), and rewrite().

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

• /home/runner/work/circt-www/circt-www/circt_src/include/circt/Reduce/Reduction.h
• /home/runner/work/circt-www/circt-www/circt_src/lib/Reduce/Reduction.cpp