BasicBlockSections.cpp File Reference

#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Analysis/EHUtils.h"
#include "llvm/Analysis/ProfileSummaryInfo.h"
#include "llvm/CodeGen/BasicBlockMatchingAndInference.h"
#include "llvm/CodeGen/BasicBlockSectionUtils.h"
#include "llvm/CodeGen/BasicBlockSectionsProfileReader.h"
#include "llvm/CodeGen/MachineBlockFrequencyInfo.h"
#include "llvm/CodeGen/MachineDominators.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachinePostDominators.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/CodeGen/TargetInstrInfo.h"
#include "llvm/IR/Function.h"
#include "llvm/InitializePasses.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/UniqueBBID.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Transforms/Utils/CodeLayout.h"
#include <optional>

Go to the source code of this file.

Functions
	INITIALIZE_PASS_BEGIN (BasicBlockSections, "bbsections-prepare", "Prepares for basic block sections, by splitting functions " "into clusters of basic blocks.", false, false) INITIALIZE_PASS_END(BasicBlockSections
bbsections Prepares for basic block by splitting functions into clusters of basic static false void	updateBranches (MachineFunction &MF, const SmallVector< MachineBasicBlock * > &PreLayoutFallThroughs)
static SmallVector< BBClusterInfo >	createBBClusterInfoForFunction (MachineFunction &MF, const BasicBlockMatchingAndInference &BMI)
static void	assignSections (MachineFunction &MF, const DenseMap< UniqueBBID, BBClusterInfo > &FuncClusterInfo)
static void	setDescendantEHBlocksCold (MachineFunction &MF)
	setDescendantEHBlocksCold - This splits all EH pads and blocks reachable only by EH pad as cold.
static bool	isColdBlock (const MachineBasicBlock &MBB, const MachineBlockFrequencyInfo *MBFI, ProfileSummaryInfo *PSI)

Variables
static cl::opt< bool >	BBSectionsDetectSourceDrift ("bbsections-detect-source-drift", cl::desc("This checks if there is a fdo instr. profile hash " "mismatch for this function"), cl::init(true), cl::Hidden)
static cl::opt< unsigned >	PercentileCutoff ("mfs-psi-cutoff", cl::desc("Percentile profile summary cutoff used to " "determine cold blocks. Unused if set to zero."), cl::init(999950), cl::Hidden)
static cl::opt< unsigned >	ColdCountThreshold ("mfs-count-threshold", cl::desc("Minimum number of times a block must be executed to be retained."), cl::init(1), cl::Hidden)
static cl::opt< bool >	SplitAllEHCode ("mfs-split-ehcode", cl::desc("Splits all EH code and it's descendants by default."), cl::init(false), cl::Hidden)
bbsections	prepare
bbsections Prepares for basic block	sections
bbsections Prepares for basic block by splitting functions into clusters of basic	blocks
bbsections Prepares for basic block by splitting functions into clusters of basic	false

Function Documentation

assignSections()

void assignSections ( MachineFunction & MF, const DenseMap< UniqueBBID, BBClusterInfo > & FuncClusterInfo )

static

Definition at line 316 of file BasicBlockSections.cpp.

References llvm::All, assert(), llvm::MBBSectionID::ColdSectionID, llvm::DenseMapBase< StorageT, KeyT, ValueT, KeyInfoT, BucketT >::end(), llvm::MBBSectionID::ExceptionSectionID, llvm::DenseMapBase< StorageT, KeyT, ValueT, KeyInfoT, BucketT >::find(), llvm::TargetOptions::FunctionSplitting, llvm::TargetMachine::getBBSectionsType(), llvm::MachineFunction::getTarget(), llvm::MachineFunction::hasBBSections(), I, llvm::List, MBB, llvm::None, llvm::TargetMachine::Options, and TII.

createBBClusterInfoForFunction()

SmallVector< BBClusterInfo > createBBClusterInfoForFunction ( MachineFunction & MF, const BasicBlockMatchingAndInference & BMI )

static

Definition at line 238 of file BasicBlockSections.cpp.

References llvm::Block, llvm::SmallVectorTemplateCommon< T, typename >::empty(), llvm::MachineFunction::getName(), llvm::BasicBlockMatchingAndInference::getWeightInfo(), llvm::instructionsWithoutDebug(), MBB, llvm::SmallVectorTemplateBase< T, bool >::push_back(), llvm::MachineFunction::RenumberBlocks(), llvm::MachineFunction::size(), and uint64_t.

INITIALIZE_PASS_BEGIN()

INITIALIZE_PASS_BEGIN	(	BasicBlockSections	,
		"bbsections-prepare"	,
		"Prepares for basic block	sections,
		by splitting functions " "into clusters of basic blocks."	,
		false	,
		false	)

References INITIALIZE_PASS_DEPENDENCY.

isColdBlock()

bool isColdBlock ( const MachineBasicBlock & MBB, const MachineBlockFrequencyInfo * MBFI, ProfileSummaryInfo * PSI )

static

Definition at line 445 of file BasicBlockSections.cpp.

References ColdCountThreshold, llvm::Count, llvm::MachineBlockFrequencyInfo::getBlockProfileCount(), llvm::ProfileSummaryInfo::hasCSInstrumentationProfile(), llvm::ProfileSummaryInfo::hasInstrumentationProfile(), llvm::ProfileSummaryInfo::hasSampleProfile(), llvm::ProfileSummaryInfo::isColdCountNthPercentile(), MBB, and PercentileCutoff.

setDescendantEHBlocksCold()

void setDescendantEHBlocksCold ( MachineFunction & MF )

static

setDescendantEHBlocksCold - This splits all EH pads and blocks reachable only by EH pad as cold.

This will help mark EH pads statically cold instead of relying on profile data.

Definition at line 437 of file BasicBlockSections.cpp.

References llvm::Block, llvm::MBBSectionID::ColdSectionID, and llvm::computeEHOnlyBlocks().

updateBranches()

bbsections Prepares for basic block by splitting functions into clusters of basic static false void updateBranches ( MachineFunction & MF, const SmallVector< MachineBasicBlock * > & PreLayoutFallThroughs )

static

Definition at line 203 of file BasicBlockSections.cpp.

References Cond, const, MBB, TBB, TII, and updateBranches().

Referenced by llvm::sortBasicBlocksAndUpdateBranches(), updateBranches(), and updatePredecessors().

Variable Documentation

BBSectionsDetectSourceDrift

cl::opt< bool > BBSectionsDetectSourceDrift("bbsections-detect-source-drift", cl::desc("This checks if there is a fdo instr. profile hash " "mismatch for this function"), cl::init(true), cl::Hidden) ( "bbsections-detect-source-drift" , cl::desc("This checks if there is a fdo instr. profile hash " "mismatch for this function") , cl::init(true) , cl::Hidden  )

static

Referenced by llvm::hasInstrProfHashMismatch().

blocks

split region exit SPIRV split region exit blocks

Definition at line 197 of file BasicBlockSections.cpp.

Referenced by blake3_hash16_avx512(), blake3_hash4_avx512(), blake3_hash4_sse2(), blake3_hash4_sse41(), blake3_hash8_avx2(), blake3_hash8_avx512(), blake3_hash_many(), blake3_hash_many_avx2(), blake3_hash_many_avx512(), blake3_hash_many_portable(), blake3_hash_many_sse2(), blake3_hash_many_sse41(), llvm::GCOVBlock::getCyclesCount(), llvm::LoopBase< BlockT, LoopT >::getExitBlocks(), llvm::LoopBase< BlockT, LoopT >::getExitingBlock(), llvm::LoopBase< BlockT, LoopT >::getExitingBlocks(), hash_one_avx512(), hash_one_portable(), hash_one_sse2(), hash_one_sse41(), and llvm::RegionBase< Tr >::print().

ColdCountThreshold

cl::opt< unsigned > ColdCountThreshold("mfs-count-threshold", cl::desc( "Minimum number of times a block must be executed to be retained."), cl::init(1), cl::Hidden) ( "mfs-count-threshold" , cl::desc( "Minimum number of times a block must be executed to be retained.") , cl::init(1) , cl::Hidden  )

static

Referenced by annotateAllFunctions(), llvm::ProfileSummaryBuilder::getColdCountThreshold(), isColdBlock(), llvm::sampleprof::SampleContextTrimmer::trimAndMergeColdContextProfiles(), and verifyFuncBFI().

false

bbsections Prepares for basic block by splitting functions into clusters of basic false

Definition at line 198 of file BasicBlockSections.cpp.

PercentileCutoff

cl::opt< unsigned > PercentileCutoff("mfs-psi-cutoff", cl::desc("Percentile profile summary cutoff used to " "determine cold blocks. Unused if set to zero."), cl::init(999950), cl::Hidden) ( "mfs-psi-cutoff" , cl::desc("Percentile profile summary cutoff used to " "determine cold blocks. Unused if set to zero.") , cl::init(999950) , cl::Hidden  )

static

Referenced by isColdBlock(), llvm::ProfileSummaryInfo::isColdBlockNthPercentile(), llvm::ProfileSummaryInfo::isColdBlockNthPercentile(), llvm::ProfileSummaryInfo::isColdCountNthPercentile(), llvm::ProfileSummaryInfo::isFunctionColdInCallGraphNthPercentile(), llvm::ProfileSummaryInfo::isFunctionHotInCallGraphNthPercentile(), llvm::ProfileSummaryInfo::isHotBlockNthPercentile(), llvm::ProfileSummaryInfo::isHotBlockNthPercentile(), and llvm::ProfileSummaryInfo::isHotCountNthPercentile().

prepare

bbsections prepare

Definition at line 195 of file BasicBlockSections.cpp.

Referenced by llvm::jitlink::ELFLinkGraphBuilder< ELFT >::buildGraph().

sections

bbsections Prepares for basic block sections

Definition at line 196 of file BasicBlockSections.cpp.

Referenced by llvm::object::ELFFile< ELFT >::dynamicEntries(), llvm::object::ELFFile< ELFT >::getDynSymtabSize(), llvm::object::ELFFile< ELFT >::getSection(), llvm::object::ELFFile< ELFT >::getSectionAndRelocations(), llvm::object::ELFFile< ELFT >::getSectionName(), llvm::object::ELFFile< ELFT >::getSHNDXTable(), llvm::object::ELFFile< ELFT >::getStringTableForSymtab(), llvm::pdb::InputFile::hasTypes(), and LLVMObjectFileCopySectionIterator().

SplitAllEHCode

cl::opt< bool > SplitAllEHCode("mfs-split-ehcode", cl::desc("Splits all EH code and it's descendants by default."), cl::init(false), cl::Hidden) ( "mfs-split-ehcode" , cl::desc("Splits all EH code and it's descendants by default.") , cl::init(false) , cl::Hidden  )

static