LLVM 20.0.0git
Public Member Functions | Static Public Member Functions | Static Public Attributes | List of all members
llvm::LazyBlockFrequencyInfoPass Class Reference

This is an alternative analysis pass to BlockFrequencyInfoWrapperPass. More...

#include "llvm/Analysis/LazyBlockFrequencyInfo.h"

Inheritance diagram for llvm::LazyBlockFrequencyInfoPass:
Inheritance graph
[legend]

Public Member Functions

 LazyBlockFrequencyInfoPass ()
 
BlockFrequencyInfogetBFI ()
 Compute and return the block frequencies.
 
const BlockFrequencyInfogetBFI () const
 Compute and return the block frequencies.
 
void getAnalysisUsage (AnalysisUsage &AU) const override
 getAnalysisUsage - This function should be overriden by passes that need analysis information to do their job.
 
bool runOnFunction (Function &F) override
 runOnFunction - Virtual method overriden by subclasses to do the per-function processing of the pass.
 
void releaseMemory () override
 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.
 
void print (raw_ostream &OS, const Module *M) const override
 print - Print out the internal state of the pass.
 
- Public Member Functions inherited from llvm::FunctionPass
 FunctionPass (char &pid)
 
PasscreatePrinterPass (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
 
Passoperator= (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 PasscreatePrinterPass (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)
 
AnalysisResolvergetResolver () 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 ImmutablePassgetAsImmutablePass ()
 
virtual PMDataManagergetAsPMDataManager ()
 
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 Member Functions

static void getLazyBFIAnalysisUsage (AnalysisUsage &AU)
 Helper for client passes to set up the analysis usage on behalf of this pass.
 
- Static Public Member Functions inherited from llvm::Pass
static const PassInfolookupPassInfo (const void *TI)
 
static const PassInfolookupPassInfo (StringRef Arg)
 
static PasscreatePass (AnalysisID ID)
 

Static Public Attributes

static char ID = 0
 

Additional Inherited Members

- 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

This is an alternative analysis pass to BlockFrequencyInfoWrapperPass.

The difference is that with this pass the block frequencies are not computed when the analysis pass is executed but rather when the BFI result is explicitly requested by the analysis client.

There are some additional requirements for any client pass that wants to use the analysis:

  1. The pass needs to initialize dependent passes with:

    INITIALIZE_PASS_DEPENDENCY(LazyBFIPass)

  2. Similarly, getAnalysisUsage should call:

    LazyBlockFrequencyInfoPass::getLazyBFIAnalysisUsage(AU)

  3. The computed BFI should be requested with getAnalysis<LazyBlockFrequencyInfoPass>().getBFI() before either LoopInfo or BPI could be invalidated for example by changing the CFG.

Note that it is expected that we wouldn't need this functionality for the new PM since with the new PM, analyses are executed on demand.

Definition at line 97 of file LazyBlockFrequencyInfo.h.

Constructor & Destructor Documentation

◆ LazyBlockFrequencyInfoPass()

LazyBlockFrequencyInfoPass::LazyBlockFrequencyInfoPass ( )

Member Function Documentation

◆ getAnalysisUsage()

void LazyBlockFrequencyInfoPass::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 43 of file LazyBlockFrequencyInfo.cpp.

References llvm::AnalysisUsage::addRequiredTransitive(), llvm::LazyBranchProbabilityInfoPass::getLazyBPIAnalysisUsage(), and llvm::AnalysisUsage::setPreservesAll().

◆ getBFI() [1/2]

BlockFrequencyInfo & llvm::LazyBlockFrequencyInfoPass::getBFI ( )
inline

Compute and return the block frequencies.

Definition at line 109 of file LazyBlockFrequencyInfo.h.

◆ getBFI() [2/2]

const BlockFrequencyInfo & llvm::LazyBlockFrequencyInfoPass::getBFI ( ) const
inline

Compute and return the block frequencies.

Definition at line 112 of file LazyBlockFrequencyInfo.h.

◆ getLazyBFIAnalysisUsage()

void LazyBlockFrequencyInfoPass::getLazyBFIAnalysisUsage ( AnalysisUsage AU)
static

◆ print()

void LazyBlockFrequencyInfoPass::print ( raw_ostream OS,
const Module M 
) const
overridevirtual

print - Print out the internal state of the pass.

This is called by Analyze to print out the contents of an analysis. Otherwise it is not necessary to implement this method. Beware that the module pointer MAY be null. This automatically forwards to a virtual function that does not provide the Module* in case the analysis doesn't need it it can just be ignored.

Reimplemented from llvm::Pass.

Definition at line 39 of file LazyBlockFrequencyInfo.cpp.

References OS.

◆ releaseMemory()

void LazyBlockFrequencyInfoPass::releaseMemory ( )
overridevirtual

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.

The default behavior of passes is to hold onto memory for the entire duration of their lifetime (which is the entire compile time). For pipelined passes, this is not a big deal because that memory gets recycled every time the pass is invoked on another program unit. For IP passes, it is more important to free memory when it is unused.

Optionally implement this function to release pass memory when it is no longer used.

Reimplemented from llvm::Pass.

Definition at line 53 of file LazyBlockFrequencyInfo.cpp.

◆ runOnFunction()

bool LazyBlockFrequencyInfoPass::runOnFunction ( Function F)
overridevirtual

runOnFunction - Virtual method overriden by subclasses to do the per-function processing of the pass.

Implements llvm::FunctionPass.

Definition at line 55 of file LazyBlockFrequencyInfo.cpp.

References F.

Member Data Documentation

◆ ID

Lazy Block Frequency true char LazyBlockFrequencyInfoPass::ID = 0
static

Definition at line 104 of file LazyBlockFrequencyInfo.h.


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