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_)

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

ConstantRange	getConstantRangeAtUse (const Use &U, bool UndefAllowed)
	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	forgetValue (Value *V)
	Remove information related to this value from the cache.

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

void	clear ()
	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 61 of file LazyValueInfo.h.

Constructor & Destructor Documentation

◆ ~LazyValueInfo()

LazyValueInfo::~LazyValueInfo ( )

Definition at line 1670 of file LazyValueInfo.cpp.

References releaseMemory().

◆ LazyValueInfo() [1/3]

llvm::LazyValueInfo::LazyValueInfo ( )

default

◆ LazyValueInfo() [2/3]

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

inline

Definition at line 45 of file LazyValueInfo.h.

◆ LazyValueInfo() [3/3]

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

inline

Definition at line 47 of file LazyValueInfo.h.

Member Function Documentation

◆ clear()

void LazyValueInfo::clear ( )

Complete flush all previously computed values.

Definition at line 2015 of file LazyValueInfo.cpp.

◆ eraseBlock()

void LazyValueInfo::eraseBlock ( BasicBlock * BB )

Inform the analysis cache that we have erased a block.

Definition at line 2010 of file LazyValueInfo.cpp.

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

◆ forgetValue()

void LazyValueInfo::forgetValue ( Value * V )

Remove information related to this value from the cache.

Definition at line 2005 of file LazyValueInfo.cpp.

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

◆ 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 1714 of file LazyValueInfo.cpp.

References llvm::BasicBlock::getModule(), llvm::Instruction::getParent(), llvm::ConstantRange::getSingleElement(), llvm::LazyValueInfoImpl::getValueInBlock(), and isKnownNonConstant().

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

◆ 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 1752 of file LazyValueInfo.cpp.

References llvm::BasicBlock::getModule(), llvm::ConstantRange::getSingleElement(), and llvm::LazyValueInfoImpl::getValueOnEdge().

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

◆ getConstantRange()

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

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 1733 of file LazyValueInfo.cpp.

References assert(), llvm::BasicBlock::getModule(), llvm::Instruction::getParent(), llvm::LazyValueInfoImpl::getValueInBlock(), and toConstantRange().

◆ getConstantRangeAtUse()

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

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

Definition at line 1742 of file LazyValueInfo.cpp.

References llvm::LazyValueInfoImpl::getValueAtUse(), and toConstantRange().

Referenced by processAbsIntrinsic(), processAnd(), processAShr(), processBinOp(), processICmp(), processMinMaxIntrinsic(), processSDivOrSRem(), processSExt(), processUDivOrURem(), processZExt(), 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 1769 of file LazyValueInfo.cpp.

References llvm::BasicBlock::getModule(), llvm::LazyValueInfoImpl::getValueOnEdge(), and toConstantRange().

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 1963 of file LazyValueInfo.cpp.

References llvm::CallingConv::C, False, llvm::Instruction::getModule(), llvm::Instruction::getParent(), getPredicateAt(), llvm::CmpInst::getSwappedPredicate(), llvm::Value::getType(), llvm::LazyValueInfoImpl::getValueInBlock(), 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 1857 of file LazyValueInfo.cpp.

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

Referenced by constantFoldCmp(), getConstantAt(), getPredicateAt(), llvm::JumpThreadingPass::processBlock(), processCallSite(), 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 1846 of file LazyValueInfo.cpp.

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

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 1680 of file LazyValueInfo.cpp.

References llvm::PreservedAnalyses::getChecker().

◆ operator=()

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

inline

Definition at line 51 of file LazyValueInfo.h.

References 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 2020 of file LazyValueInfo.cpp.

References F, and OS.

◆ releaseMemory()

void LazyValueInfo::releaseMemory ( )

Definition at line 1672 of file LazyValueInfo.cpp.

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 1999 of file LazyValueInfo.cpp.

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()

◆ forgetValue()

◆ getConstant()

◆ getConstantOnEdge()

◆ getConstantRange()

◆ getConstantRangeAtUse()

◆ getConstantRangeOnEdge()

◆ getPredicateAt() [1/2]

◆ getPredicateAt() [2/2]

◆ getPredicateOnEdge()

◆ invalidate()

◆ operator=()

◆ printLVI()

◆ releaseMemory()

◆ threadEdge()

Friends And Related Function Documentation

◆ LazyValueInfoWrapperPass