This pass implements the reg bank selector pass used in the GlobalISel pipeline. More...

#include "llvm/CodeGen/GlobalISel/RegBankSelect.h"

Inheritance diagram for llvm::RegBankSelect:

Collaboration diagram for llvm::RegBankSelect:

[legend]

Classes
class	EdgeInsertPoint
	Insertion point on an edge. More...

class	InsertPoint
	Abstract class used to represent an insertion point in a CFG. More...

class	InstrInsertPoint
	Insertion point before or after an instruction. More...

class	MBBInsertPoint
	Insertion point at the beginning or end of a basic block. More...

class	RepairingPlacement
	Struct used to represent the placement of a repairing point for a given operand. More...

Public Types
enum	Mode { Fast, Greedy }
	List of the modes supported by the RegBankSelect pass. More...

Public Member Functions
	RegBankSelect (Mode RunningMode=Fast)
	Create a RegBankSelect pass with the specified `RunningMode`. More...

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

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

MachineFunctionProperties	getRequiredProperties () const override

MachineFunctionProperties	getSetProperties () const override

bool	runOnMachineFunction (MachineFunction &MF) override
	Walk through `MF` and assign a register bank to every virtual register that are still mapped to nothing. More...

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. More...

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. More...

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. More...

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

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

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

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

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

void	dump () const

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

void	setResolver (AnalysisResolver *AR)

AnalysisResolver *	getResolver () const

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. More...

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

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. More...

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. More...

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

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. More...

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

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

template<typename AnalysisType >
AnalysisType &	getAnalysisID (AnalysisID PI, Function &F)

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)

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

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. More...

Detailed Description

This pass implements the reg bank selector pass used in the GlobalISel pipeline.

At the end of this pass, all register operands have been assigned

Definition at line 91 of file RegBankSelect.h.

Member Enumeration Documentation

◆ Mode

enum llvm::RegBankSelect::Mode

List of the modes supported by the RegBankSelect pass.

Enumerator

Fast

Assign the register banks as fast as possible (default).

Greedy

Greedily minimize the cost of assigning register banks.

This should produce code of greater quality, but will require more compile time.

Definition at line 96 of file RegBankSelect.h.

Constructor & Destructor Documentation

◆ RegBankSelect()

llvm::RegBankSelect::RegBankSelect ( Mode RunningMode = Fast )

Create a RegBankSelect pass with the specified RunningMode.

Referenced by llvm::RegBankSelect::RepairingPlacement::switchTo().

Member Function Documentation

◆ getAnalysisUsage()

void RegBankSelect::getAnalysisUsage ( AnalysisUsage & ) const

overridevirtual

getAnalysisUsage - This function should be overriden by passes that need analysis information to do their job.

If a pass specifies that it uses a particular analysis result to this function, it can then use the getAnalysis<AnalysisType>() function, below.

Reimplemented from llvm::Pass.

Definition at line 100 of file RegBankSelect.cpp.

Referenced by getPassName().

◆ getPassName()

StringRef llvm::RegBankSelect::getPassName ( ) const

inlineoverridevirtual

getPassName - Return a nice clean name for a pass.

This usually implemented in terms of the name that is registered by one of the Registration templates, but can be overloaded directly.

Reimplemented from llvm::Pass.

Definition at line 622 of file RegBankSelect.h.

References getAnalysisUsage().

◆ getRequiredProperties()

MachineFunctionProperties llvm::RegBankSelect::getRequiredProperties ( ) const

inlineoverridevirtual

Reimplemented from llvm::MachineFunctionPass.

Definition at line 626 of file RegBankSelect.h.

References llvm::MachineFunctionProperties::IsSSA, llvm::MachineFunctionProperties::Legalized, and llvm::MachineFunctionProperties::set().

◆ getSetProperties()

MachineFunctionProperties llvm::RegBankSelect::getSetProperties ( ) const

inlineoverridevirtual

Reimplemented from llvm::MachineFunctionPass.

Definition at line 632 of file RegBankSelect.h.

References llvm::MachineFunctionProperties::RegBankSelected, runOnMachineFunction(), and llvm::MachineFunctionProperties::set().

◆ runOnMachineFunction()

bool RegBankSelect::runOnMachineFunction ( MachineFunction & MF )

overridevirtual

Walk through MF and assign a register bank to every virtual register that are still mapped to nothing.

The target needs to provide a RegisterBankInfo and in particular override RegisterBankInfo::getInstrMapping.

Simplified algo:

RBI = MF.subtarget.getRegBankInfo()
MIRBuilder.setMF(MF)
for each bb in MF
  for each inst in bb
    MIRBuilder.setInstr(inst)
    MappingCosts = RBI.getMapping(inst);
    Idx = findIdxOfMinCost(MappingCosts)
    CurRegBank = MappingCosts[Idx].RegBank
    MRI.setRegBank(inst.getOperand(0).getReg(), CurRegBank)
    for each argument in inst
      if (CurRegBank != argument.RegBank)
        ArgReg = argument.getReg()
        Tmp = MRI.createNewVirtual(MRI.getSize(ArgReg), CurRegBank)
        MIRBuilder.buildInstr(COPY, Tmp, ArgReg)
        inst.getOperand(argument.getOperandNo()).setReg(Tmp)