Interface that should be implemented by any caller of transformCFGToSCF. More...

#include "mlir/Transforms/CFGToSCF.h"

Inheritance diagram for mlir::CFGToSCFInterface:

Public Member Functions
virtual	~CFGToSCFInterface ()=default

virtual FailureOr< Operation * >	createStructuredBranchRegionOp (OpBuilder &builder, Operation *controlFlowCondOp, TypeRange resultTypes, MutableArrayRef< Region > regions)=0
	Creates a structured control flow operation branching to one of `regions`. More...

virtual LogicalResult	createStructuredBranchRegionTerminatorOp (Location loc, OpBuilder &builder, Operation branchRegionOp, Operation replacedControlFlowOp, ValueRange results)=0
	Creates a return-like terminator for a branch region of the op returned by `createStructuredBranchRegionOp`. More...

virtual FailureOr< Operation * >	createStructuredDoWhileLoopOp (OpBuilder &builder, Operation *replacedOp, ValueRange loopValuesInit, Value condition, ValueRange loopValuesNextIter, Region &&loopBody)=0
	Creates a structured control flow operation representing a do-while loop. More...

virtual Value	getCFGSwitchValue (Location loc, OpBuilder &builder, unsigned value)=0
	Creates a constant operation with a result representing `value` that is suitable as flag for `createCFGSwitchOp`. More...

virtual void	createCFGSwitchOp (Location loc, OpBuilder &builder, Value flag, ArrayRef< unsigned > caseValues, BlockRange caseDestinations, ArrayRef< ValueRange > caseArguments, Block *defaultDest, ValueRange defaultArgs)=0
	Creates a switch CFG branch operation branching to one of `caseDestinations` or `defaultDest`. More...

virtual Value	getUndefValue (Location loc, OpBuilder &builder, Type type)=0
	Creates a constant operation returning an undefined instance of `type`. More...

virtual FailureOr< Operation * >	createUnreachableTerminator (Location loc, OpBuilder &builder, Region &region)=0
	Creates a return-like terminator indicating unreachable. More...

void	createSingleDestinationBranch (Location loc, OpBuilder &builder, Value dummyFlag, Block *destination, ValueRange arguments)
	Helper function to create an unconditional branch using `createCFGSwitchOp`. More...

void	createConditionalBranch (Location loc, OpBuilder &builder, Value condition, Block trueDest, ValueRange trueArgs, Block falseDest, ValueRange falseArgs)
	Helper function to create a conditional branch using `createCFGSwitchOp`. More...

Detailed Description

Interface that should be implemented by any caller of transformCFGToSCF.

The transformation requires the caller to 1) create switch-like control flow operations for intermediate transformations and 2) to create the desired structured control flow ops.

Definition at line 28 of file CFGToSCF.h.

Constructor & Destructor Documentation

◆ ~CFGToSCFInterface()

virtual mlir::CFGToSCFInterface::~CFGToSCFInterface ( )

virtualdefault

Member Function Documentation

◆ createCFGSwitchOp()

virtual void mlir::CFGToSCFInterface::createCFGSwitchOp	(	Location	loc,
		OpBuilder &	builder,
		Value	flag,
		ArrayRef< unsigned >	caseValues,
		BlockRange	caseDestinations,
		ArrayRef< ValueRange >	caseArguments,
		Block *	defaultDest,
		ValueRange	defaultArgs
	)

pure virtual

Creates a switch CFG branch operation branching to one of caseDestinations or defaultDest.

This is used by the transformation for intermediate transformations before lifting to structured control flow. The switch op branches based on flag which is guaranteed to be of the same type as values returned by getCFGSwitchValue. The insertion block of the builder is guaranteed to have its predecessors already set to create an equivalent CFG after this operation. Note: caseValues and other related ranges may be empty to represent an unconditional branch.

Implemented in mlir::ControlFlowToSCFTransformation.

Referenced by createConditionalBranch(), and createSingleDestinationBranch().

◆ createConditionalBranch()

void mlir::CFGToSCFInterface::createConditionalBranch	(	Location	loc,
		OpBuilder &	builder,
		Value	condition,
		Block *	trueDest,
		ValueRange	trueArgs,
		Block *	falseDest,
		ValueRange	falseArgs
	)

inline

Helper function to create a conditional branch using createCFGSwitchOp.

Definition at line 126 of file CFGToSCF.h.

References createCFGSwitchOp().

Referenced by createSingleExitingLatch().

◆ createSingleDestinationBranch()

void mlir::CFGToSCFInterface::createSingleDestinationBranch	(	Location	loc,
		OpBuilder &	builder,
		Value	dummyFlag,
		Block *	destination,
		ValueRange	arguments
	)

inline

Helper function to create an unconditional branch using createCFGSwitchOp.

Definition at line 117 of file CFGToSCF.h.

References createCFGSwitchOp().

◆ createStructuredBranchRegionOp()

virtual FailureOr<Operation *> mlir::CFGToSCFInterface::createStructuredBranchRegionOp	(	OpBuilder &	builder,
		Operation *	controlFlowCondOp,
		TypeRange	resultTypes,
		MutableArrayRef< Region >	regions
	)

pure virtual

Creates a structured control flow operation branching to one of regions.

It replaces controlFlowCondOp and must have resultTypes as results. regions contains the list of branch regions corresponding to each successor of controlFlowCondOp. Their bodies must simply be taken and left as is. Returns failure if incapable of converting the control flow graph operation.

Implemented in mlir::ControlFlowToSCFTransformation.

Referenced by transformToStructuredCFBranches().

◆ createStructuredBranchRegionTerminatorOp()

virtual LogicalResult mlir::CFGToSCFInterface::createStructuredBranchRegionTerminatorOp	(	Location	loc,
		OpBuilder &	builder,
		Operation *	branchRegionOp,
		Operation *	replacedControlFlowOp,
		ValueRange	results
	)

pure virtual

Creates a return-like terminator for a branch region of the op returned by createStructuredBranchRegionOp.

branchRegionOp is the operation returned by createStructuredBranchRegionOp. replacedControlFlowOp is the control flow op being replaced by the terminator or nullptr if the terminator is not replacing any existing control flow op. results are the values that should be returned by the branch region.

Implemented in mlir::ControlFlowToSCFTransformation.

Referenced by transformToStructuredCFBranches().

◆ createStructuredDoWhileLoopOp()

virtual FailureOr<Operation *> mlir::CFGToSCFInterface::createStructuredDoWhileLoopOp	(	OpBuilder &	builder,
		Operation *	replacedOp,
		ValueRange	loopValuesInit,
		Value	condition,
		ValueRange	loopValuesNextIter,
		Region &&	loopBody
	)

pure virtual

Creates a structured control flow operation representing a do-while loop.

The do-while loop is expected to have the exact same result types as the types of the iteration values. loopBody is the body of the loop. The implementation of this function must create a suitable terminator op at the end of the last block in loopBody which continues the loop if condition is 1 and exits the loop if 0. loopValuesNextIter are the values that have to be passed as the iteration values for the next iteration if continuing, or the result of the loop if exiting. condition is guaranteed to be of the same type as values returned by getCFGSwitchValue with either 0 or 1 as value.

loopValuesInit are the values used to initialize the iteration values of the loop. Returns failure if incapable of creating a loop op.

Implemented in mlir::ControlFlowToSCFTransformation.

Referenced by transformCyclesToSCFLoops().

◆ createUnreachableTerminator()

virtual FailureOr<Operation *> mlir::CFGToSCFInterface::createUnreachableTerminator	(	Location	loc,
		OpBuilder &	builder,
		Region &	region
	)

pure virtual

Creates a return-like terminator indicating unreachable.

This is required when the transformation encounters a statically known infinite loop. Since structured control flow ops are not terminators, after lifting an infinite loop, a terminator has to be placed after to possibly satisfy the terminator requirement of the region originally passed to transformCFGToSCF.

region is guaranteed to be the region originally passed to transformCFGToSCF and the op is guaranteed to always be an op in a block directly nested under region after the transformation.

Returns failure if incapable of creating an unreachable terminator.

Implemented in mlir::ControlFlowToSCFTransformation.

Referenced by createSingleExitingLatch().