SCCPSolver - This interface class is a general purpose solver for Sparse Conditional Constant Propagation (SCCP). More...

#include "llvm/Transforms/Utils/SCCPSolver.h"

Public Member Functions
	SCCPSolver (const DataLayout &DL, std::function< const TargetLibraryInfo &(Function &)> GetTLI, LLVMContext &Ctx)

	~SCCPSolver ()

void	addPredicateInfo (Function &F, DominatorTree &DT, AssumptionCache &AC)

bool	markBlockExecutable (BasicBlock *BB)
	markBlockExecutable - This method can be used by clients to mark all of the blocks that are known to be intrinsically live in the processed unit.

const PredicateBase *	getPredicateInfoFor (Instruction *I)

void	trackValueOfGlobalVariable (GlobalVariable *GV)
	trackValueOfGlobalVariable - Clients can use this method to inform the SCCPSolver that it should track loads and stores to the specified global variable if it can.

void	addTrackedFunction (Function *F)
	addTrackedFunction - If the SCCP solver is supposed to track calls into and out of the specified function (which cannot have its address taken), this method must be called.

void	addToMustPreserveReturnsInFunctions (Function *F)
	Add function to the list of functions whose return cannot be modified.

bool	mustPreserveReturn (Function *F)
	Returns true if the return of the given function cannot be modified.

void	addArgumentTrackedFunction (Function *F)

bool	isArgumentTrackedFunction (Function *F)
	Returns true if the given function is in the solver's set of argument-tracked functions.

void	solve ()
	Solve - Solve for constants and executable blocks.

bool	resolvedUndefsIn (Function &F)
	resolvedUndefsIn - While solving the dataflow for a function, we assume that branches on undef values cannot reach any of their successors.

void	solveWhileResolvedUndefsIn (Module &M)

void	solveWhileResolvedUndefsIn (SmallVectorImpl< Function * > &WorkList)

void	solveWhileResolvedUndefs ()

bool	isBlockExecutable (BasicBlock *BB) const

bool	isEdgeFeasible (BasicBlock From, BasicBlock To) const

std::vector< ValueLatticeElement >	getStructLatticeValueFor (Value *V) const

void	removeLatticeValueFor (Value *V)

void	resetLatticeValueFor (CallBase *Call)
	Invalidate the Lattice Value of `Call` and its users after specializing the call.

const ValueLatticeElement &	getLatticeValueFor (Value *V) const

const MapVector< Function *, ValueLatticeElement > &	getTrackedRetVals ()
	getTrackedRetVals - Get the inferred return value map.

const DenseMap< GlobalVariable *, ValueLatticeElement > &	getTrackedGlobals ()
	getTrackedGlobals - Get and return the set of inferred initializers for global variables.

const SmallPtrSet< Function *, 16 >	getMRVFunctionsTracked ()
	getMRVFunctionsTracked - Get the set of functions which return multiple values tracked by the pass.

void	markOverdefined (Value *V)
	markOverdefined - Mark the specified value overdefined.

void	trackValueOfArgument (Argument *V)
	trackValueOfArgument - Mark the specified argument overdefined unless it have range attribute.

bool	isStructLatticeConstant (Function F, StructType STy)

Constant *	getConstant (const ValueLatticeElement &LV, Type *Ty) const
	Helper to return a Constant if `LV` is either a constant or a constant range with a single element.

Constant *	getConstantOrNull (Value *V) const
	Return either a Constant or nullptr for a given Value.

SmallPtrSetImpl< Function * > &	getArgumentTrackedFunctions ()
	Return a reference to the set of argument tracked functions.

void	setLatticeValueForSpecializationArguments (Function *F, const SmallVectorImpl< ArgInfo > &Args)
	Set the Lattice Value for the arguments of a specialization `F`.

void	markFunctionUnreachable (Function *F)
	Mark all of the blocks in function `F` non-executable.

void	visit (Instruction *I)

void	visitCall (CallInst &I)

bool	simplifyInstsInBlock (BasicBlock &BB, SmallPtrSetImpl< Value * > &InsertedValues, Statistic &InstRemovedStat, Statistic &InstReplacedStat)

bool	removeNonFeasibleEdges (BasicBlock BB, DomTreeUpdater &DTU, BasicBlock &NewUnreachableBB) const

bool	tryToReplaceWithConstant (Value *V)

Static Public Member Functions
static bool	isConstant (const ValueLatticeElement &LV)

static bool	isOverdefined (const ValueLatticeElement &LV)

Detailed Description

SCCPSolver - This interface class is a general purpose solver for Sparse Conditional Constant Propagation (SCCP).

Definition at line 65 of file SCCPSolver.h.

Constructor & Destructor Documentation

◆ SCCPSolver()

SCCPSolver::SCCPSolver	(	const DataLayout &	DL,
		std::function< const TargetLibraryInfo &(Function &)>	GetTLI,
		LLVMContext &	Ctx
	)

Definition at line 2043 of file SCCPSolver.cpp.

◆ ~SCCPSolver()

SCCPSolver::~SCCPSolver ( )

default

Member Function Documentation

◆ addArgumentTrackedFunction()

void SCCPSolver::addArgumentTrackedFunction ( Function * F )

Definition at line 2080 of file SCCPSolver.cpp.

References F.

Referenced by runIPSCCP().

◆ addPredicateInfo()

void SCCPSolver::addPredicateInfo	(	Function &	F,
		DominatorTree &	DT,
		AssumptionCache &	AC
	)

Definition at line 2051 of file SCCPSolver.cpp.

References F.

Referenced by runIPSCCP().

◆ addToMustPreserveReturnsInFunctions()

void SCCPSolver::addToMustPreserveReturnsInFunctions ( Function * F )

Add function to the list of functions whose return cannot be modified.

Definition at line 2072 of file SCCPSolver.cpp.

References F.

Referenced by tryToReplaceWithConstant().

◆ addTrackedFunction()

void SCCPSolver::addTrackedFunction ( Function * F )

addTrackedFunction - If the SCCP solver is supposed to track calls into and out of the specified function (which cannot have its address taken), this method must be called.

Definition at line 2068 of file SCCPSolver.cpp.

References F.

Referenced by runIPSCCP().

◆ getArgumentTrackedFunctions()

SmallPtrSetImpl< Function * > & SCCPSolver::getArgumentTrackedFunctions ( )

Return a reference to the set of argument tracked functions.

Definition at line 2165 of file SCCPSolver.cpp.

◆ getConstant()

Constant * SCCPSolver::getConstant	(	const ValueLatticeElement &	LV,
		Type *	Ty
	)		const

Helper to return a Constant if LV is either a constant or a constant range with a single element.

Definition at line 2156 of file SCCPSolver.cpp.

◆ getConstantOrNull()

Constant * SCCPSolver::getConstantOrNull ( Value * V ) const

Return either a Constant or nullptr for a given Value.

Definition at line 2161 of file SCCPSolver.cpp.

Referenced by tryToReplaceWithConstant().

◆ getLatticeValueFor()

const ValueLatticeElement & SCCPSolver::getLatticeValueFor ( Value * V ) const

Definition at line 2128 of file SCCPSolver.cpp.

Referenced by findReturnsToZap(), llvm::refineInstruction(), and llvm::replaceSignedInst().

◆ getMRVFunctionsTracked()

const SmallPtrSet< Function *, 16 > SCCPSolver::getMRVFunctionsTracked ( )

getMRVFunctionsTracked - Get the set of functions which return multiple values tracked by the pass.

Definition at line 2142 of file SCCPSolver.cpp.

Referenced by runIPSCCP().

◆ getPredicateInfoFor()

const PredicateBase * SCCPSolver::getPredicateInfoFor ( Instruction * I )

Definition at line 2060 of file SCCPSolver.cpp.

References I.

Referenced by runIPSCCP().

◆ getStructLatticeValueFor()

std::vector< ValueLatticeElement > SCCPSolver::getStructLatticeValueFor ( Value * V ) const

Definition at line 2116 of file SCCPSolver.cpp.

◆ getTrackedGlobals()

const DenseMap< GlobalVariable *, ValueLatticeElement > & SCCPSolver::getTrackedGlobals ( )

getTrackedGlobals - Get and return the set of inferred initializers for global variables.

Definition at line 2138 of file SCCPSolver.cpp.

Referenced by runIPSCCP().

◆ getTrackedRetVals()

const MapVector< Function *, ValueLatticeElement > & SCCPSolver::getTrackedRetVals ( )

getTrackedRetVals - Get the inferred return value map.

Definition at line 2133 of file SCCPSolver.cpp.

Referenced by llvm::FunctionSpecializer::run(), and runIPSCCP().

◆ isArgumentTrackedFunction()

bool SCCPSolver::isArgumentTrackedFunction ( Function * F )

Returns true if the given function is in the solver's set of argument-tracked functions.

Definition at line 2084 of file SCCPSolver.cpp.

References F.

Referenced by findReturnsToZap().

◆ isBlockExecutable()

bool SCCPSolver::isBlockExecutable ( BasicBlock * BB ) const

Definition at line 2107 of file SCCPSolver.cpp.

Referenced by llvm::InstCostVisitor::isBlockExecutable(), runIPSCCP(), and runSCCP().

◆ isConstant()

bool llvm::SCCPSolver::isConstant ( const ValueLatticeElement & LV )

static

Definition at line 55 of file SCCPSolver.cpp.

References llvm::ValueLatticeElement::getConstantRange(), llvm::ValueLatticeElement::isConstant(), llvm::ValueLatticeElement::isConstantRange(), and llvm::ConstantRange::isSingleElement().

Referenced by llvm::SCCPInstVisitor::getConstantOrNull(), isOverdefined(), llvm::SCCPInstVisitor::isStructLatticeConstant(), and runIPSCCP().

◆ isEdgeFeasible()

bool SCCPSolver::isEdgeFeasible	(	BasicBlock *	From,
		BasicBlock *	To
	)		const

Definition at line 2111 of file SCCPSolver.cpp.

References From.

Referenced by removeNonFeasibleEdges().

◆ isOverdefined()

bool llvm::SCCPSolver::isOverdefined ( const ValueLatticeElement & LV )

static

Definition at line 60 of file SCCPSolver.cpp.

References isConstant(), and llvm::ValueLatticeElement::isUnknownOrUndef().

Referenced by findReturnsToZap(), llvm::SCCPInstVisitor::getConstantOrNull(), llvm::FunctionSpecializer::run(), and runIPSCCP().

◆ isStructLatticeConstant()

bool SCCPSolver::isStructLatticeConstant	(	Function *	F,
		StructType *	STy
	)

Definition at line 2152 of file SCCPSolver.cpp.

References F.

Referenced by llvm::FunctionSpecializer::run(), and runIPSCCP().

◆ markBlockExecutable()

bool SCCPSolver::markBlockExecutable ( BasicBlock * BB )

markBlockExecutable - This method can be used by clients to mark all of the blocks that are known to be intrinsically live in the processed unit.

This returns true if the block was not considered live before.

Definition at line 2056 of file SCCPSolver.cpp.

Referenced by runIPSCCP(), and runSCCP().

◆ markFunctionUnreachable()

void SCCPSolver::markFunctionUnreachable ( Function * F )

Mark all of the blocks in function F non-executable.

Clients can used this method to erase a function from the module (e.g., if it has been completely specialized and is no longer needed).

Definition at line 2174 of file SCCPSolver.cpp.

References F.

◆ markOverdefined()

void SCCPSolver::markOverdefined ( Value * V )

markOverdefined - Mark the specified value overdefined.

This works with both scalars and structs.

Definition at line 2146 of file SCCPSolver.cpp.

Referenced by runSCCP().

◆ mustPreserveReturn()

bool SCCPSolver::mustPreserveReturn ( Function * F )

Returns true if the return of the given function cannot be modified.

Definition at line 2076 of file SCCPSolver.cpp.

References F.

Referenced by findReturnsToZap().

◆ removeLatticeValueFor()

void SCCPSolver::removeLatticeValueFor ( Value * V )

Definition at line 2120 of file SCCPSolver.cpp.

Referenced by llvm::replaceSignedInst().

◆ removeNonFeasibleEdges()

bool llvm::SCCPSolver::removeNonFeasibleEdges	(	BasicBlock *	BB,
		DomTreeUpdater &	DTU,
		BasicBlock *&	NewUnreachableBB
	)		const

◆ resetLatticeValueFor()

void SCCPSolver::resetLatticeValueFor ( CallBase * Call )

Invalidate the Lattice Value of Call and its users after specializing the call.

Then recompute it.

Definition at line 2124 of file SCCPSolver.cpp.

Referenced by llvm::FunctionSpecializer::run().

◆ resolvedUndefsIn()

bool SCCPSolver::resolvedUndefsIn ( Function & F )

resolvedUndefsIn - While solving the dataflow for a function, we assume that branches on undef values cannot reach any of their successors.

However, this is not a safe assumption. After we solve dataflow, this method should be use to handle this. If this returns true, the solver should be rerun.

Definition at line 2090 of file SCCPSolver.cpp.

References F.

Referenced by runSCCP().

◆ setLatticeValueForSpecializationArguments()

void SCCPSolver::setLatticeValueForSpecializationArguments	(	Function *	F,
		const SmallVectorImpl< ArgInfo > &	Args
	)

Set the Lattice Value for the arguments of a specialization F.

If an argument is Constant then its lattice value is marked with the corresponding actual argument in Args. Otherwise, its lattice value is inherited (copied) from the corresponding formal argument in Args.

Definition at line 2169 of file SCCPSolver.cpp.

References F.

◆ simplifyInstsInBlock()

bool llvm::SCCPSolver::simplifyInstsInBlock	(	BasicBlock &	BB,
		SmallPtrSetImpl< Value * > &	InsertedValues,
		Statistic &	InstRemovedStat,
		Statistic &	InstReplacedStat
	)

Definition at line 244 of file SCCPSolver.cpp.

References llvm::canRemoveInstruction(), llvm::make_early_inc_range(), llvm::refineInstruction(), llvm::replaceSignedInst(), and tryToReplaceWithConstant().

Referenced by runIPSCCP(), and runSCCP().

◆ solve()

void SCCPSolver::solve ( )

Solve - Solve for constants and executable blocks.

Definition at line 2088 of file SCCPSolver.cpp.

Referenced by runSCCP().

◆ solveWhileResolvedUndefs()

void SCCPSolver::solveWhileResolvedUndefs ( )

Definition at line 2103 of file SCCPSolver.cpp.

Referenced by llvm::FunctionSpecializer::run().

◆ solveWhileResolvedUndefsIn() [1/2]

void SCCPSolver::solveWhileResolvedUndefsIn ( Module & M )

Definition at line 2094 of file SCCPSolver.cpp.

Referenced by llvm::FunctionSpecializer::run(), and runIPSCCP().

◆ solveWhileResolvedUndefsIn() [2/2]

void SCCPSolver::solveWhileResolvedUndefsIn ( SmallVectorImpl< Function * > & WorkList )

Definition at line 2099 of file SCCPSolver.cpp.

◆ trackValueOfArgument()

void SCCPSolver::trackValueOfArgument ( Argument * V )

trackValueOfArgument - Mark the specified argument overdefined unless it have range attribute.

This works with both scalars and structs.

Definition at line 2148 of file SCCPSolver.cpp.

Referenced by runIPSCCP().

◆ trackValueOfGlobalVariable()

void SCCPSolver::trackValueOfGlobalVariable ( GlobalVariable * GV )

trackValueOfGlobalVariable - Clients can use this method to inform the SCCPSolver that it should track loads and stores to the specified global variable if it can.

This is only legal to call if performing Interprocedural SCCP.

Definition at line 2064 of file SCCPSolver.cpp.

Referenced by runIPSCCP().

◆ tryToReplaceWithConstant()

bool llvm::SCCPSolver::tryToReplaceWithConstant ( Value * V )

Definition at line 76 of file SCCPSolver.cpp.

References addToMustPreserveReturnsInFunctions(), llvm::canRemoveInstruction(), llvm::dbgs(), F, llvm::CallBase::getCalledFunction(), getConstantOrNull(), llvm::CallBase::getOperandBundle(), llvm::CallBase::isMustTailCall(), LLVM_DEBUG, and llvm::LLVMContext::OB_clang_arc_attachedcall.

Referenced by runIPSCCP(), and simplifyInstsInBlock().

◆ visit()

void SCCPSolver::visit ( Instruction * I )

Definition at line 2178 of file SCCPSolver.cpp.

References I.

◆ visitCall()

void SCCPSolver::visitCall ( CallInst & I )

Definition at line 2180 of file SCCPSolver.cpp.

References I.

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

include/llvm/Transforms/Utils/SCCPSolver.h
lib/Transforms/Utils/SCCPSolver.cpp

Public Member Functions

Static Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ SCCPSolver()

◆ ~SCCPSolver()

Member Function Documentation

◆ addArgumentTrackedFunction()

◆ addPredicateInfo()

◆ addToMustPreserveReturnsInFunctions()

◆ addTrackedFunction()

◆ getArgumentTrackedFunctions()

◆ getConstant()

◆ getConstantOrNull()

◆ getLatticeValueFor()

◆ getMRVFunctionsTracked()

◆ getPredicateInfoFor()

◆ getStructLatticeValueFor()

◆ getTrackedGlobals()

◆ getTrackedRetVals()

◆ isArgumentTrackedFunction()

◆ isBlockExecutable()

◆ isConstant()

◆ isEdgeFeasible()

◆ isOverdefined()

◆ isStructLatticeConstant()

◆ markBlockExecutable()

◆ markFunctionUnreachable()

◆ markOverdefined()

◆ mustPreserveReturn()

◆ removeLatticeValueFor()

◆ removeNonFeasibleEdges()

◆ resetLatticeValueFor()

◆ resolvedUndefsIn()

◆ setLatticeValueForSpecializationArguments()

◆ simplifyInstsInBlock()

◆ solve()

◆ solveWhileResolvedUndefs()

◆ solveWhileResolvedUndefsIn() [1/2]

◆ solveWhileResolvedUndefsIn() [2/2]

◆ trackValueOfArgument()

◆ trackValueOfGlobalVariable()

◆ tryToReplaceWithConstant()

◆ visit()

◆ visitCall()