#include "CodeGen/SpillPlacement.h"

Inheritance diagram for llvm::SpillPlacement:

[legend]

Classes
struct	BlockConstraint
	BlockConstraint - Entry and exit constraints for a basic block. More...

struct	Node
	Node - Each edge bundle corresponds to a Hopfield node. More...

Public Types
enum	BorderConstraint { DontCare , PrefReg , PrefSpill , PrefBoth , MustSpill }
	BorderConstraint - A basic block has separate constraints for entry and exit. More...

Public Member Functions
	SpillPlacement ()

	~SpillPlacement () override

void	prepare (BitVector &RegBundles)
	prepare - Reset state and prepare for a new spill placement computation.

void	addConstraints (ArrayRef< BlockConstraint > LiveBlocks)
	addConstraints - Add constraints and biases.

void	addPrefSpill (ArrayRef< unsigned > Blocks, bool Strong)
	addPrefSpill - Add PrefSpill constraints to all blocks listed.

void	addLinks (ArrayRef< unsigned > Links)
	addLinks - Add transparent blocks with the given numbers.

bool	scanActiveBundles ()
	scanActiveBundles - Perform an initial scan of all bundles activated by addConstraints and addLinks, updating their state.

void	iterate ()
	iterate - Update the network iteratively until convergence, or new bundles are found.

ArrayRef< unsigned >	getRecentPositive ()
	getRecentPositive - Return an array of bundles that became positive during the previous call to scanActiveBundles or iterate.

bool	finish ()
	finish - Compute the optimal spill code placement given the constraints.

BlockFrequency	getBlockFrequency (unsigned Number) const
	getBlockFrequency - Return the estimated block execution frequency per function invocation.

Public Member Functions inherited from llvm::MachineFunctionPass
bool	doInitialization (Module &) override
	doInitialization - Virtual method overridden by subclasses to do any necessary initialization before any pass is run.

Public Member Functions inherited from llvm::FunctionPass
	FunctionPass (char &pid)

Pass *	createPrinterPass (raw_ostream &OS, const std::string &Banner) const override
	createPrinterPass - Get a function printer pass.

virtual bool	runOnFunction (Function &F)=0
	runOnFunction - Virtual method overriden by subclasses to do the per-function processing of the pass.

void	assignPassManager (PMStack &PMS, PassManagerType T) override
	Find appropriate Function Pass Manager or Call Graph Pass Manager in the PM Stack and add self into that manager.

PassManagerType	getPotentialPassManagerType () const override
	Return what kind of Pass Manager can manage this pass.

Public Member Functions inherited from llvm::Pass
	Pass (PassKind K, char &pid)

	Pass (const Pass &)=delete

Pass &	operator= (const Pass &)=delete

virtual	~Pass ()

PassKind	getPassKind () const

virtual StringRef	getPassName () const
	getPassName - Return a nice clean name for a pass.

AnalysisID	getPassID () const
	getPassID - Return the PassID number that corresponds to this pass.

virtual bool	doInitialization (Module &)
	doInitialization - Virtual method overridden by subclasses to do any necessary initialization before any pass is run.

virtual bool	doFinalization (Module &)
	doFinalization - Virtual method overriden by subclasses to do any necessary clean up after all passes have run.

virtual void	print (raw_ostream &OS, const Module *M) const
	print - Print out the internal state of the pass.

void	dump () const

virtual Pass *	createPrinterPass (raw_ostream &OS, const std::string &Banner) const =0
	createPrinterPass - Get a Pass appropriate to print the IR this pass operates on (Module, Function or MachineFunction).

virtual void	assignPassManager (PMStack &, PassManagerType)
	Each pass is responsible for assigning a pass manager to itself.

virtual void	preparePassManager (PMStack &)
	Check if available pass managers are suitable for this pass or not.

virtual PassManagerType	getPotentialPassManagerType () const
	Return what kind of Pass Manager can manage this pass.

void	setResolver (AnalysisResolver *AR)

AnalysisResolver *	getResolver () const

virtual void	getAnalysisUsage (AnalysisUsage &) const
	getAnalysisUsage - This function should be overriden by passes that need analysis information to do their job.

virtual void	releaseMemory ()
	releaseMemory() - This member can be implemented by a pass if it wants to be able to release its memory when it is no longer needed.

virtual void *	getAdjustedAnalysisPointer (AnalysisID ID)
	getAdjustedAnalysisPointer - This method is used when a pass implements an analysis interface through multiple inheritance.

virtual ImmutablePass *	getAsImmutablePass ()

virtual PMDataManager *	getAsPMDataManager ()

virtual void	verifyAnalysis () const
	verifyAnalysis() - This member can be implemented by a analysis pass to check state of analysis information.

virtual void	dumpPassStructure (unsigned Offset=0)

template<typename AnalysisType >
AnalysisType *	getAnalysisIfAvailable () const
	getAnalysisIfAvailable<AnalysisType>() - Subclasses use this function to get analysis information that might be around, for example to update it.

bool	mustPreserveAnalysisID (char &AID) const
	mustPreserveAnalysisID - This method serves the same function as getAnalysisIfAvailable, but works if you just have an AnalysisID.

template<typename AnalysisType >
AnalysisType &	getAnalysis () const
	getAnalysis<AnalysisType>() - This function is used by subclasses to get to the analysis information that they claim to use by overriding the getAnalysisUsage function.

template<typename AnalysisType >
AnalysisType &	getAnalysis (Function &F, bool *Changed=nullptr)
	getAnalysis<AnalysisType>() - This function is used by subclasses to get to the analysis information that they claim to use by overriding the getAnalysisUsage function.

template<typename AnalysisType >
AnalysisType &	getAnalysisID (AnalysisID PI) const

template<typename AnalysisType >
AnalysisType &	getAnalysisID (AnalysisID PI, Function &F, bool *Changed=nullptr)

Static Public Attributes
static char	ID = 0

Additional Inherited Members
Static Public Member Functions inherited from llvm::Pass
static const PassInfo *	lookupPassInfo (const void *TI)

static const PassInfo *	lookupPassInfo (StringRef Arg)

static Pass *	createPass (AnalysisID ID)

Protected Member Functions inherited from llvm::MachineFunctionPass
	MachineFunctionPass (char &ID)

virtual bool	runOnMachineFunction (MachineFunction &MF)=0
	runOnMachineFunction - This method must be overloaded to perform the desired machine code transformation or analysis.

void	getAnalysisUsage (AnalysisUsage &AU) const override
	getAnalysisUsage - Subclasses that override getAnalysisUsage must call this.

virtual MachineFunctionProperties	getRequiredProperties () const

virtual MachineFunctionProperties	getSetProperties () const

virtual MachineFunctionProperties	getClearedProperties () const

Protected Member Functions inherited from llvm::FunctionPass
bool	skipFunction (const Function &F) const
	Optional passes call this function to check whether the pass should be skipped.

Detailed Description

Definition at line 42 of file SpillPlacement.h.

Member Enumeration Documentation

◆ BorderConstraint

enum llvm::SpillPlacement::BorderConstraint

BorderConstraint - A basic block has separate constraints for entry and exit.

Enumerator
DontCare	Block doesn't care / variable not live.
PrefReg	Block entry/exit prefers a register.
PrefSpill	Block entry/exit prefers a stack slot.
PrefBoth	Block entry prefers both register and stack.
MustSpill	A register is impossible, variable must be spilled.

Definition at line 78 of file SpillPlacement.h.

Constructor & Destructor Documentation

◆ SpillPlacement()

llvm::SpillPlacement::SpillPlacement ( )

inline

Definition at line 73 of file SpillPlacement.h.

◆ ~SpillPlacement()

llvm::SpillPlacement::~SpillPlacement ( )

inlineoverride

Definition at line 74 of file SpillPlacement.h.

Member Function Documentation

◆ addConstraints()

void SpillPlacement::addConstraints ( ArrayRef< BlockConstraint > LiveBlocks )

addConstraints - Add constraints and biases.

addConstraints - Compute node biases and weights from a set of constraints.

This method may be called more than once to accumulate constraints.

Parameters

LiveBlocks Constraints for blocks that have the variable live in or live out.

Set a bit in NodeMask for each active node.

Definition at line 260 of file SpillPlacement.cpp.

References llvm::SpillPlacement::Node::addBias(), DontCare, and llvm::EdgeBundles::getBundle().

◆ addLinks()

void SpillPlacement::addLinks ( ArrayRef< unsigned > Links )

addLinks - Add transparent blocks with the given numbers.

Definition at line 295 of file SpillPlacement.cpp.

References llvm::SpillPlacement::Node::addLink(), llvm::EdgeBundles::getBundle(), and llvm::Number.

◆ addPrefSpill()

void SpillPlacement::addPrefSpill	(	ArrayRef< unsigned >	Blocks,
		bool	Strong
	)

addPrefSpill - Add PrefSpill constraints to all blocks listed.

addPrefSpill - Same as addConstraints(PrefSpill)

This is equivalent to calling addConstraint with identical BlockConstraints with Entry = Exit = PrefSpill, and ChangesValue = false.

Parameters

Blocks	Array of block numbers that prefer to spill in and out.
Strong	When true, double the negative bias for these blocks.

Definition at line 281 of file SpillPlacement.cpp.

References llvm::SpillPlacement::Node::addBias(), B, Blocks, llvm::EdgeBundles::getBundle(), and PrefSpill.

◆ finish()

bool SpillPlacement::finish ( )

finish - Compute the optimal spill code placement given the constraints.

No MustSpill constraints will be violated, and the smallest possible number of PrefX constraints will be violated, weighted by expected execution frequencies. The selected bundles are returned in the bitvector passed to prepare().

Returns: True if a perfect solution was found, allowing the variable to be in a register through all relevant bundles.

Definition at line 363 of file SpillPlacement.cpp.

References assert(), llvm::BitVector::reset(), and llvm::BitVector::set_bits().

◆ getBlockFrequency()

BlockFrequency llvm::SpillPlacement::getBlockFrequency ( unsigned Number ) const

inline

getBlockFrequency - Return the estimated block execution frequency per function invocation.

Definition at line 153 of file SpillPlacement.h.

References llvm::Number.

◆ getRecentPositive()

ArrayRef< unsigned > llvm::SpillPlacement::getRecentPositive ( )

inline

getRecentPositive - Return an array of bundles that became positive during the previous call to scanActiveBundles or iterate.

Definition at line 140 of file SpillPlacement.h.

◆ iterate()

void SpillPlacement::iterate ( )

iterate - Update the network iteratively until convergence, or new bundles are found.

iterate - Repeatedly update the Hopfield nodes until stability or the maximum number of iterations is reached.

Definition at line 334 of file SpillPlacement.cpp.

References llvm::SmallVectorImpl< T >::clear(), llvm::SparseSet< ValueT, KeyFunctorT, SparseT >::empty(), llvm::EdgeBundles::getNumBundles(), llvm::SparseSet< ValueT, KeyFunctorT, SparseT >::pop_back_val(), and llvm::SmallVectorTemplateBase< T, bool >::push_back().

◆ prepare()

void SpillPlacement::prepare ( BitVector & RegBundles )

prepare - Reset state and prepare for a new spill placement computation.

Parameters

RegBundles Bit vector to receive the edge bundles where the variable should be kept in a register. Each bit corresponds to an edge bundle, a set bit means the variable should be kept in a register through the bundle. A clear bit means the variable should be spilled. This vector is retained.

Definition at line 353 of file SpillPlacement.cpp.

References llvm::BitVector::clear(), llvm::SmallVectorImpl< T >::clear(), llvm::SparseSet< ValueT, KeyFunctorT, SparseT >::clear(), llvm::EdgeBundles::getNumBundles(), and llvm::BitVector::resize().

◆ scanActiveBundles()

bool SpillPlacement::scanActiveBundles ( )

scanActiveBundles - Perform an initial scan of all bundles activated by addConstraints and addLinks, updating their state.

Add all the bundles that now prefer a register to RecentPositive. Prepare internal data structures for iterate. Return true is there are any positive nodes.

Definition at line 311 of file SpillPlacement.cpp.

References llvm::SmallVectorImpl< T >::clear(), llvm::SmallVectorBase< Size_T >::empty(), llvm::SmallVectorTemplateBase< T, bool >::push_back(), and llvm::BitVector::set_bits().

Member Data Documentation

◆ ID

char SpillPlacement::ID = 0

static

Definition at line 71 of file SpillPlacement.h.

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

lib/CodeGen/SpillPlacement.h
lib/CodeGen/SpillPlacement.cpp

Classes

Public Types

Public Member Functions

Static Public Attributes

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

◆ BorderConstraint

Constructor & Destructor Documentation

◆ SpillPlacement()

◆ ~SpillPlacement()

Member Function Documentation

◆ addConstraints()

◆ addLinks()

◆ addPrefSpill()

◆ finish()

◆ getBlockFrequency()

◆ getRecentPositive()

◆ iterate()

◆ prepare()

◆ scanActiveBundles()

Member Data Documentation

◆ ID