#include "llvm/CodeGen/SwitchLoweringUtils.h"

Inheritance diagram for llvm::SwitchCG::SwitchLowering:

Classes
struct	SplitWorkItemInfo

Public Member Functions
	SwitchLowering (FunctionLoweringInfo &funcinfo)
void	init (const TargetLowering &tli, const TargetMachine &tm, const DataLayout &dl)
void	findJumpTables (CaseClusterVector &Clusters, const SwitchInst SI, std::optional< SDLoc > SL, MachineBasicBlock DefaultMBB, ProfileSummaryInfo PSI, BlockFrequencyInfo BFI)
bool	buildJumpTable (const CaseClusterVector &Clusters, unsigned First, unsigned Last, const SwitchInst SI, const std::optional< SDLoc > &SL, MachineBasicBlock DefaultMBB, CaseCluster &JTCluster)
void	findBitTestClusters (CaseClusterVector &Clusters, const SwitchInst *SI)
bool	buildBitTests (CaseClusterVector &Clusters, unsigned First, unsigned Last, const SwitchInst *SI, CaseCluster &BTCluster)
	Build a bit test cluster from Clusters[First..Last].
virtual void	addSuccessorWithProb (MachineBasicBlock Src, MachineBasicBlock Dst, BranchProbability Prob=BranchProbability::getUnknown())=0
unsigned	caseClusterRank (const CaseCluster &CC, CaseClusterIt First, CaseClusterIt Last)
	Determine the rank by weight of CC in [First,Last].
SplitWorkItemInfo	computeSplitWorkItemInfo (const SwitchWorkListItem &W)
	Compute information to balance the tree based on branch probabilities to create a near-optimal (in terms of search time given key frequency) binary search tree.
virtual	~SwitchLowering ()=default

Public Attributes
std::vector< CaseBlock >	SwitchCases
	Vector of CaseBlock structures used to communicate SwitchInst code generation information.
std::vector< JumpTableBlock >	JTCases
	Vector of JumpTable structures used to communicate SwitchInst code generation information.
std::vector< BitTestBlock >	BitTestCases
	Vector of BitTestBlock structures used to communicate SwitchInst code generation information.

Detailed Description

Definition at line 258 of file SwitchLoweringUtils.h.

Constructor & Destructor Documentation

◆ SwitchLowering()

llvm::SwitchCG::SwitchLowering::SwitchLowering ( FunctionLoweringInfo & funcinfo )

inline

Definition at line 260 of file SwitchLoweringUtils.h.

Referenced by llvm::SelectionDAGBuilder::SDAGSwitchLowering::SDAGSwitchLowering().

◆ ~SwitchLowering()

virtual llvm::SwitchCG::SwitchLowering::~SwitchLowering ( )

virtualdefault

Member Function Documentation

◆ addSuccessorWithProb()

virtual void llvm::SwitchCG::SwitchLowering::addSuccessorWithProb	(	MachineBasicBlock *	Src,
		MachineBasicBlock *	Dst,
		BranchProbability	Prob = BranchProbability::getUnknown() )

pure virtual

Implemented in llvm::SelectionDAGBuilder::SDAGSwitchLowering.

References llvm::First, llvm::BranchProbability::getUnknown(), and llvm::Last.

Referenced by buildJumpTable().

◆ buildBitTests()

bool SwitchCG::SwitchLowering::buildBitTests	(	CaseClusterVector &	Clusters,
		unsigned	First,
		unsigned	Last,
		const SwitchInst *	SI,
		CaseCluster &	BTCluster )

Build a bit test cluster from Clusters[First..Last].

Returns false if it decides it's not a good idea.

Definition at line 367 of file SwitchLoweringUtils.cpp.

References assert(), llvm::SwitchCG::CaseBits::Bits, BitTestCases, llvm::SwitchCG::CaseCluster::bitTests(), llvm::BitWidth, llvm::SwitchCG::CC_Range, llvm::BitVector::count(), llvm::SwitchCG::CaseBits::ExtraProb, llvm::First, llvm::APInt::getZero(), llvm::BranchProbability::getZero(), llvm::Hi, High, I, llvm::Last, llvm::Lo, llvm::Low, llvm::SwitchCG::CaseBits::Mask, MBB, llvm::SmallVectorTemplateBase< T, bool >::push_back(), llvm::BitVector::set(), and llvm::sort().

Referenced by findBitTestClusters().

◆ buildJumpTable()

bool SwitchCG::SwitchLowering::buildJumpTable	(	const CaseClusterVector &	Clusters,
		unsigned	First,
		unsigned	Last,
		const SwitchInst *	SI,
		const std::optional< SDLoc > &	SL,
		MachineBasicBlock *	DefaultMBB,
		CaseCluster &	JTCluster )

◆ caseClusterRank()

unsigned SwitchCG::SwitchLowering::caseClusterRank	(	const CaseCluster &	CC,
		CaseClusterIt	First,
		CaseClusterIt	Last )

Determine the rank by weight of CC in [First,Last].

If CC has more weight than each cluster in the range, its rank is 0.

Definition at line 499 of file SwitchLoweringUtils.cpp.

References llvm::First, llvm::ConstantInt::getValue(), llvm::Last, llvm::SwitchCG::CaseCluster::Low, llvm::SwitchCG::CaseCluster::Prob, and X.

Referenced by computeSplitWorkItemInfo().

◆ computeSplitWorkItemInfo()

llvm::SwitchCG::SwitchLowering::SplitWorkItemInfo SwitchCG::SwitchLowering::computeSplitWorkItemInfo ( const SwitchWorkListItem & W )

Compute information to balance the tree based on branch probabilities to create a near-optimal (in terms of search time given key frequency) binary search tree.

See e.g. Kurt Mehlhorn "Nearly Optimal Binary Search Trees" (1975).

Definition at line 512 of file SwitchLoweringUtils.cpp.

References assert(), caseClusterRank(), and I.

◆ findBitTestClusters()

void SwitchCG::SwitchLowering::findBitTestClusters	(	CaseClusterVector &	Clusters,
		const SwitchInst *	SI )

Definition at line 268 of file SwitchLoweringUtils.cpp.

References assert(), llvm::BitWidth, buildBitTests(), llvm::CallingConv::C, llvm::SwitchCG::CC_JumpTable, llvm::SwitchCG::CC_Range, llvm::BitVector::count(), llvm::First, llvm::EVT::getSizeInBits(), High, llvm::Last, MBB, N, llvm::None, llvm::BitVector::set(), and llvm::ISD::SHL.

◆ findJumpTables()

void SwitchCG::SwitchLowering::findJumpTables	(	CaseClusterVector &	Clusters,
		const SwitchInst *	SI,
		std::optional< SDLoc >	SL,
		MachineBasicBlock *	DefaultMBB,
		ProfileSummaryInfo *	PSI,
		BlockFrequencyInfo *	BFI )

Definition at line 46 of file SwitchLoweringUtils.cpp.

References assert(), buildJumpTable(), llvm::CallingConv::C, llvm::SwitchCG::CC_Range, llvm::First, llvm::SwitchCG::getJumpTableNumCases(), llvm::SwitchCG::getJumpTableRange(), llvm::Hi, High, I, llvm::Last, llvm::Lo, N, llvm::None, Range, and UINT64_MAX.

◆ init()

void llvm::SwitchCG::SwitchLowering::init	(	const TargetLowering &	tli,
		const TargetMachine &	tm,
		const DataLayout &	dl )

inline

Definition at line 262 of file SwitchLoweringUtils.h.

Member Data Documentation

◆ BitTestCases

std::vector<BitTestBlock> llvm::SwitchCG::SwitchLowering::BitTestCases

Vector of BitTestBlock structures used to communicate SwitchInst code generation information.

Definition at line 279 of file SwitchLoweringUtils.h.

Referenced by buildBitTests().

◆ JTCases

std::vector<JumpTableBlock> llvm::SwitchCG::SwitchLowering::JTCases

Vector of JumpTable structures used to communicate SwitchInst code generation information.

Definition at line 275 of file SwitchLoweringUtils.h.

Referenced by buildJumpTable().

◆ SwitchCases

std::vector<CaseBlock> llvm::SwitchCG::SwitchLowering::SwitchCases

Vector of CaseBlock structures used to communicate SwitchInst code generation information.

Definition at line 271 of file SwitchLoweringUtils.h.

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

include/llvm/CodeGen/SwitchLoweringUtils.h
lib/CodeGen/SwitchLoweringUtils.cpp

Classes

Public Member Functions

Public Attributes