Write one or more ContextNodes to the provided raw_fd_stream. More...

#include "llvm/ProfileData/PGOCtxProfWriter.h"

Inheritance diagram for llvm::PGOCtxProfileWriter:

Public Member Functions
	PGOCtxProfileWriter (raw_ostream &Out, std::optional< unsigned > VersionOverride=std::nullopt, bool IncludeEmpty=false)
	~PGOCtxProfileWriter ()
void	startContextSection () override
void	writeContextual (const ctx_profile::ContextNode &RootNode, const ctx_profile::ContextNode *Unhandled, uint64_t TotalRootEntryCount) override
void	endContextSection () override
void	startFlatSection () override
void	writeFlat (ctx_profile::GUID Guid, const uint64_t *Buffer, size_t BufferSize) override
void	endFlatSection () override
Public Member Functions inherited from llvm::ctx_profile::ProfileWriter
virtual	~ProfileWriter ()=default

Static Public Attributes
static constexpr unsigned	CodeLen = 2
static constexpr uint32_t	CurrentVersion = 4
static constexpr unsigned	VBREncodingBits = 6
static constexpr StringRef	ContainerMagic = "CTXP"

Detailed Description

Write one or more ContextNodes to the provided raw_fd_stream.

The caller must destroy the PGOCtxProfileWriter object before closing the stream. The design allows serializing a bunch of contexts embedded in some other file. The overall format is:

[... other data written to the stream...] SubBlock(ProfileMetadataBlockID) Version SubBlock(ContextNodeBlockID) [RECORDS] SubBlock(ContextNodeBlockID) [RECORDS] [... more SubBlocks] EndBlock EndBlock

The "RECORDS" are bitsream records. The IDs are in CtxProfileCodes (except) for Version, which is just for metadata). All contexts will have Guid and Counters, and all but the roots have CalleeIndex. The order in which the records appear does not matter, but they must precede any subcontexts, because that helps keep the reader code simpler.

Subblock containment captures the context->subcontext relationship. The "next()" relationship in the raw profile, between call targets of indirect calls, are just modeled as peer subblocks where the callee index is the same.

Versioning: the writer may produce additional records not known by the reader. The version number indicates a more structural change. The current version, in particular, is set up to expect optional extensions like value profiling - which would appear as additional records. For example, value profiling would produce a new record with a new record ID, containing the profiled values (much like the counters)

Definition at line 78 of file PGOCtxProfWriter.h.

Constructor & Destructor Documentation

◆ PGOCtxProfileWriter()

PGOCtxProfileWriter::PGOCtxProfileWriter	(	raw_ostream &	Out,
		std::optional< unsigned >	VersionOverride = std::nullopt,
		bool	IncludeEmpty = false )

Definition at line 29 of file PGOCtxProfWriter.cpp.

References llvm::CallsiteIndex, ContainerMagic, llvm::ContextNodeBlockID, llvm::ContextRootBlockID, llvm::ContextsSectionBlockID, llvm::Counters, llvm::Data, llvm::FlatProfileBlockID, llvm::FlatProfilesSectionBlockID, llvm::Guid, IncludeEmptyOpt, llvm::ProfileMetadataBlockID, llvm::TotalRootEntryCount, llvm::UnhandledBlockID, and llvm::raw_ostream::write().

◆ ~PGOCtxProfileWriter()

llvm::PGOCtxProfileWriter::~PGOCtxProfileWriter ( )

inline

Definition at line 95 of file PGOCtxProfWriter.h.

Member Function Documentation

◆ endContextSection()

void PGOCtxProfileWriter::endContextSection ( )

overridevirtual

Implements llvm::ctx_profile::ProfileWriter.

Definition at line 134 of file PGOCtxProfWriter.cpp.

Referenced by llvm::createCtxProfFromYAML().

◆ endFlatSection()

void PGOCtxProfileWriter::endFlatSection ( )

overridevirtual

Implements llvm::ctx_profile::ProfileWriter.

Definition at line 135 of file PGOCtxProfWriter.cpp.

Referenced by llvm::createCtxProfFromYAML().

◆ startContextSection()

void PGOCtxProfileWriter::startContextSection ( )

overridevirtual

Implements llvm::ctx_profile::ProfileWriter.

Definition at line 125 of file PGOCtxProfWriter.cpp.

References CodeLen, and llvm::ContextsSectionBlockID.

Referenced by llvm::createCtxProfFromYAML().

◆ startFlatSection()

void PGOCtxProfileWriter::startFlatSection ( )

overridevirtual

Implements llvm::ctx_profile::ProfileWriter.

Definition at line 129 of file PGOCtxProfWriter.cpp.

References CodeLen, and llvm::FlatProfilesSectionBlockID.

Referenced by llvm::createCtxProfFromYAML().

◆ writeContextual()

void PGOCtxProfileWriter::writeContextual	(	const ctx_profile::ContextNode &	RootNode,
		const ctx_profile::ContextNode *	Unhandled,
		uint64_t	TotalRootEntryCount )