This pass computes, caches, and vends lazy value constraint information. More...

#include "llvm/Analysis/LazyValueInfo.h"

Public Types
enum	Tristate { Unknown = -1 , False = 0 , True = 1 }
	This is used to return true/false/dunno results. More...

Public Member Functions
	~LazyValueInfo ()

	LazyValueInfo ()=default

	LazyValueInfo (AssumptionCache AC_, const DataLayout DL_, TargetLibraryInfo *TLI_)

	LazyValueInfo (LazyValueInfo &&Arg)

LazyValueInfo &	operator= (LazyValueInfo &&Arg)

Tristate	getPredicateOnEdge (unsigned Pred, Value V, Constant C, BasicBlock FromBB, BasicBlock ToBB, Instruction *CxtI=nullptr)
	Determine whether the specified value comparison with a constant is known to be true or false on the specified CFG edge.

Tristate	getPredicateAt (unsigned Pred, Value V, Constant C, Instruction *CxtI, bool UseBlockValue)
	Determine whether the specified value comparison with a constant is known to be true or false at the specified instruction.

Tristate	getPredicateAt (unsigned Pred, Value LHS, Value RHS, Instruction *CxtI, bool UseBlockValue)
	Determine whether the specified value comparison is known to be true or false at the specified instruction.

Constant *	getConstant (Value V, Instruction CxtI)
	Determine whether the specified value is known to be a constant at the specified instruction.

ConstantRange	getConstantRange (Value V, Instruction CxtI, bool UndefAllowed=true)
	Return the ConstantRange constraint that is known to hold for the specified value at the specified instruction.

ConstantRange	getConstantRangeAtUse (const Use &U, bool UndefAllowed=true)
	Return the ConstantRange constraint that is known to hold for the value at a specific use-site.

Constant *	getConstantOnEdge (Value V, BasicBlock FromBB, BasicBlock ToBB, Instruction CxtI=nullptr)
	Determine whether the specified value is known to be a constant on the specified edge.

ConstantRange	getConstantRangeOnEdge (Value V, BasicBlock FromBB, BasicBlock ToBB, Instruction CxtI=nullptr)
	Return the ConstantRage constraint that is known to hold for the specified value on the specified edge.

void	threadEdge (BasicBlock PredBB, BasicBlock OldSucc, BasicBlock *NewSucc)
	Inform the analysis cache that we have threaded an edge from PredBB to OldSucc to be from PredBB to NewSucc instead.

void	eraseBlock (BasicBlock *BB)
	Inform the analysis cache that we have erased a block.

void	clear (const Module *M)
	Complete flush all previously computed values.

void	printLVI (Function &F, DominatorTree &DTree, raw_ostream &OS)
	Print the \LazyValueInfo Analysis.

void	releaseMemory ()

bool	invalidate (Function &F, const PreservedAnalyses &PA, FunctionAnalysisManager::Invalidator &Inv)
	Handle invalidation events in the new pass manager.

Friends
class	LazyValueInfoWrapperPass

Detailed Description

This pass computes, caches, and vends lazy value constraint information.

Definition at line 31 of file LazyValueInfo.h.

Member Enumeration Documentation

◆ Tristate

enum llvm::LazyValueInfo::Tristate

This is used to return true/false/dunno results.

Enumerator
Unknown
False
True

Definition at line 60 of file LazyValueInfo.h.

Constructor & Destructor Documentation

◆ ~LazyValueInfo()

LazyValueInfo::~LazyValueInfo ( )

Definition at line 1573 of file LazyValueInfo.cpp.

References releaseMemory().

◆ LazyValueInfo() [1/3]

llvm::LazyValueInfo::LazyValueInfo ( )

default

◆ LazyValueInfo() [2/3]

llvm::LazyValueInfo::LazyValueInfo	(	AssumptionCache *	AC_,
		const DataLayout *	DL_,
		TargetLibraryInfo *	TLI_
	)

inline

Definition at line 42 of file LazyValueInfo.h.

◆ LazyValueInfo() [3/3]

llvm::LazyValueInfo::LazyValueInfo ( LazyValueInfo && Arg )

inline

Definition at line 45 of file LazyValueInfo.h.

References Arg.

Member Function Documentation

◆ clear()

void LazyValueInfo::clear ( const Module * M )

Complete flush all previously computed values.

Definition at line 1969 of file LazyValueInfo.cpp.

References getImpl().

◆ eraseBlock()

void LazyValueInfo::eraseBlock ( BasicBlock * BB )

Inform the analysis cache that we have erased a block.

Definition at line 1963 of file LazyValueInfo.cpp.

References getImpl(), and llvm::BasicBlock::getModule().

Referenced by llvm::JumpThreadingPass::maybeMergeBasicBlockIntoOnlyPred(), and llvm::JumpThreadingPass::runImpl().

◆ getConstant()

Constant * LazyValueInfo::getConstant	(	Value *	V,
		Instruction *	CxtI
	)

Determine whether the specified value is known to be a constant at the specified instruction.

Return null if not.

Definition at line 1618 of file LazyValueInfo.cpp.

References llvm::ConstantInt::get(), llvm::Value::getContext(), getImpl(), llvm::BasicBlock::getModule(), llvm::Instruction::getParent(), llvm::ConstantRange::getSingleElement(), and isKnownNonConstant().

Referenced by llvm::JumpThreadingPass::computeValueKnownInPredecessorsImpl(), getConstantAt(), processCallSite(), processMemAccess(), and processSelect().

◆ getConstantOnEdge()

Constant * LazyValueInfo::getConstantOnEdge	(	Value *	V,
		BasicBlock *	FromBB,
		BasicBlock *	ToBB,
		Instruction *	CxtI = `nullptr`
	)

Determine whether the specified value is known to be a constant on the specified edge.

Return null if not.

Definition at line 1699 of file LazyValueInfo.cpp.

References llvm::ConstantInt::get(), llvm::Value::getContext(), getImpl(), llvm::BasicBlock::getModule(), and llvm::ConstantRange::getSingleElement().

Referenced by llvm::JumpThreadingPass::computeValueKnownInPredecessorsImpl(), llvm::JumpThreadingPass::evaluateOnPredecessorEdge(), getValueOnEdge(), and simplifyCommonValuePhi().

◆ getConstantRange()

ConstantRange LazyValueInfo::getConstantRange	(	Value *	V,
		Instruction *	CxtI,
		bool	UndefAllowed = `true`
	)

Return the ConstantRange constraint that is known to hold for the specified value at the specified instruction.

This may only be called on integer-typed Values.

Definition at line 1637 of file LazyValueInfo.cpp.

References assert(), getImpl(), llvm::Type::getIntegerBitWidth(), llvm::BasicBlock::getModule(), llvm::Instruction::getParent(), llvm::Value::getType(), and llvm::Type::isIntegerTy().

Referenced by getConstantRangeAtUse(), processBinOp(), and processICmp().

◆ getConstantRangeAtUse()

ConstantRange LazyValueInfo::getConstantRangeAtUse	(	const Use &	U,
		bool	UndefAllowed = `true`
	)

Return the ConstantRange constraint that is known to hold for the value at a specific use-site.

Definition at line 1655 of file LazyValueInfo.cpp.

References llvm::Use::get(), getConstantRange(), getEdgeValueLocal(), llvm::Use::getUser(), getValueFromCondition(), I, llvm::ConstantRange::intersectWith(), llvm::isSafeToSpeculativelyExecute(), PHI, SI, and llvm::Value::use_begin().

Referenced by processAnd(), processAShr(), processSDivOrSRem(), processSExt(), processUDivOrURem(), and willNotOverflow().

◆ getConstantRangeOnEdge()

ConstantRange LazyValueInfo::getConstantRangeOnEdge	(	Value *	V,
		BasicBlock *	FromBB,
		BasicBlock *	ToBB,
		Instruction *	CxtI = `nullptr`
	)

Return the ConstantRage constraint that is known to hold for the specified value on the specified edge.

This may be only be called on integer-typed Values.

Definition at line 1716 of file LazyValueInfo.cpp.

References assert(), getImpl(), llvm::Type::getIntegerBitWidth(), llvm::BasicBlock::getModule(), and llvm::Value::getType().

Referenced by llvm::JumpThreadingPass::computeValueKnownInPredecessorsImpl().

◆ getPredicateAt() [1/2]

LazyValueInfo::Tristate LazyValueInfo::getPredicateAt	(	unsigned	Pred,
		Value *	LHS,
		Value *	RHS,
		Instruction *	CxtI,
		bool	UseBlockValue
	)

Determine whether the specified value comparison is known to be true or false at the specified instruction.

While this takes two Value's, it still requires that one of them is a constant. Pred is a CmpInst predicate. If UseBlockValue is true, the block value is also taken into account.

Definition at line 1919 of file LazyValueInfo.cpp.

References llvm::CallingConv::C, False, llvm::ValueLatticeElement::getCompare(), getImpl(), llvm::Instruction::getModule(), llvm::Instruction::getParent(), getPredicateAt(), llvm::CmpInst::getSwappedPredicate(), llvm::Value::getType(), llvm::ValueLatticeElement::isOverdefined(), LHS, llvm::CmpInst::makeCmpResultType(), P, RHS, True, and Unknown.

◆ getPredicateAt() [2/2]

LazyValueInfo::Tristate LazyValueInfo::getPredicateAt	(	unsigned	Pred,
		Value *	V,
		Constant *	C,
		Instruction *	CxtI,
		bool	UseBlockValue
	)

Determine whether the specified value comparison with a constant is known to be true or false at the specified instruction.

Pred is a CmpInst predicate. If UseBlockValue is true, the block value is also taken into account.

Definition at line 1815 of file LazyValueInfo.cpp.

References llvm::CallingConv::C, DL, False, getImpl(), llvm::Instruction::getModule(), llvm::Instruction::getParent(), getPredicateOnEdge(), getPredicateResult(), llvm::Value::getType(), llvm::CmpInst::ICMP_EQ, llvm::CmpInst::ICMP_NE, llvm::isKnownNonZero(), llvm::Type::isPointerTy(), PHI, llvm::pred_begin(), llvm::pred_end(), llvm::Value::stripPointerCastsSameRepresentation(), True, and Unknown.

Referenced by constantFoldCmp(), getConstantAt(), getPredicateAt(), processAbsIntrinsic(), llvm::JumpThreadingPass::processBlock(), processCallSite(), processMinMaxIntrinsic(), and processSwitch().

◆ getPredicateOnEdge()

LazyValueInfo::Tristate LazyValueInfo::getPredicateOnEdge	(	unsigned	Pred,
		Value *	V,
		Constant *	C,
		BasicBlock *	FromBB,
		BasicBlock *	ToBB,
		Instruction *	CxtI = `nullptr`
	)

Determine whether the specified value comparison with a constant is known to be true or false on the specified CFG edge.

Pred is a CmpInst predicate.

Definition at line 1804 of file LazyValueInfo.cpp.

References llvm::CallingConv::C, getImpl(), llvm::BasicBlock::getModule(), and getPredicateResult().

Referenced by llvm::JumpThreadingPass::computeValueKnownInPredecessorsImpl(), getPredicateAt(), getValueOnEdge(), and llvm::JumpThreadingPass::tryToUnfoldSelect().

◆ invalidate()

bool LazyValueInfo::invalidate	(	Function &	F,
		const PreservedAnalyses &	PA,
		FunctionAnalysisManager::Invalidator &	Inv
	)

Handle invalidation events in the new pass manager.

Definition at line 1583 of file LazyValueInfo.cpp.

References llvm::PreservedAnalyses::getChecker().

◆ operator=()

LazyValueInfo & llvm::LazyValueInfo::operator= ( LazyValueInfo && Arg )

inline

Definition at line 49 of file LazyValueInfo.h.

References Arg, DL, and releaseMemory().

◆ printLVI()

void LazyValueInfo::printLVI	(	Function &	F,
		DominatorTree &	DTree,
		raw_ostream &	OS
	)

Print the \LazyValueInfo Analysis.

We pass in the DTree that is required for identifying which basic blocks we can solve/print for, in the LVIPrinter.

Definition at line 1975 of file LazyValueInfo.cpp.

References F, and getImpl().

◆ releaseMemory()

void LazyValueInfo::releaseMemory ( )

Definition at line 1575 of file LazyValueInfo.cpp.

References getImpl().

Referenced by operator=(), llvm::LazyValueInfoWrapperPass::releaseMemory(), and ~LazyValueInfo().

◆ threadEdge()

void LazyValueInfo::threadEdge	(	BasicBlock *	PredBB,
		BasicBlock *	OldSucc,
		BasicBlock *	NewSucc
	)

Inform the analysis cache that we have threaded an edge from PredBB to OldSucc to be from PredBB to NewSucc instead.

Definition at line 1955 of file LazyValueInfo.cpp.

References getImpl(), and llvm::BasicBlock::getModule().

Referenced by llvm::JumpThreadingPass::threadEdge().

Friends And Related Function Documentation

◆ LazyValueInfoWrapperPass

friend class LazyValueInfoWrapperPass

friend

Definition at line 32 of file LazyValueInfo.h.

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

include/llvm/Analysis/LazyValueInfo.h
lib/Analysis/LazyValueInfo.cpp

Public Types

Public Member Functions

Friends

Detailed Description

Member Enumeration Documentation

◆ Tristate

Constructor & Destructor Documentation

◆ ~LazyValueInfo()

◆ LazyValueInfo() [1/3]

◆ LazyValueInfo() [2/3]

◆ LazyValueInfo() [3/3]

Member Function Documentation

◆ clear()

◆ eraseBlock()

◆ getConstant()

◆ getConstantOnEdge()

◆ getConstantRange()

◆ getConstantRangeAtUse()

◆ getConstantRangeOnEdge()

◆ getPredicateAt() [1/2]

◆ getPredicateAt() [2/2]

◆ getPredicateOnEdge()

◆ invalidate()

◆ operator=()

◆ printLVI()

◆ releaseMemory()

◆ threadEdge()

Friends And Related Function Documentation

◆ LazyValueInfoWrapperPass