The main scalar evolution driver. More...

#include "llvm/Analysis/ScalarEvolution.h"

Classes
struct	ExitLimit
	Information about the number of loop iterations for which a loop exit's branch condition evaluates to the not-taken path. More...

class	FoldID

struct	LoopInvariantPredicate

Public Types
enum	LoopDisposition { LoopVariant , LoopInvariant , LoopComputable }
	An enum describing the relationship between a SCEV and a loop. More...

enum	BlockDisposition { DoesNotDominateBlock , DominatesBlock , ProperlyDominatesBlock }
	An enum describing the relationship between a SCEV and a basic block. More...

enum	ExitCountKind { Exact , ConstantMaximum , SymbolicMaximum }
	The terms "backedge taken count" and "exit count" are used interchangeably to refer to the number of times the backedge of a loop has executed before the loop is exited. More...

enum	MonotonicPredicateType { MonotonicallyIncreasing , MonotonicallyDecreasing }
	A predicate is said to be monotonically increasing if may go from being false to being true as the loop iterates, but never the other way around. More...

Public Member Functions
	ScalarEvolution (Function &F, TargetLibraryInfo &TLI, AssumptionCache &AC, DominatorTree &DT, LoopInfo &LI)

	ScalarEvolution (ScalarEvolution &&Arg)

	~ScalarEvolution ()

LLVMContext &	getContext () const

bool	isSCEVable (Type *Ty) const
	Test if values of the given type are analyzable within the SCEV framework.

uint64_t	getTypeSizeInBits (Type *Ty) const
	Return the size in bits of the specified type, for which isSCEVable must return true.

Type *	getEffectiveSCEVType (Type *Ty) const
	Return a type with the same bitwidth as the given type and which represents how SCEV will treat the given type, for which isSCEVable must return true.

Type *	getWiderType (Type Ty1, Type Ty2) const

bool	instructionCouldExistWitthOperands (const SCEV A, const SCEV B)
	Return true if there exists a point in the program at which both A and B could be operands to the same instruction.

bool	containsAddRecurrence (const SCEV *S)
	Return true if the SCEV is a scAddRecExpr or it contains scAddRecExpr.

bool	willNotOverflow (Instruction::BinaryOps BinOp, bool Signed, const SCEV LHS, const SCEV RHS, const Instruction *CtxI=nullptr)
	Is operation `BinOp` between `LHS` and `RHS` provably does not have a signed/unsigned overflow (`Signed`)? If `CtxI` is specified, the no-overflow fact should be true in the context of this instruction.

std::optional< SCEV::NoWrapFlags >	getStrengthenedNoWrapFlagsFromBinOp (const OverflowingBinaryOperator *OBO)
	Parse NSW/NUW flags from add/sub/mul IR binary operation `Op` into SCEV no-wrap flags, and deduce flag[s] that aren't known yet.

void	registerUser (const SCEV User, ArrayRef< const SCEV > Ops)
	Notify this ScalarEvolution that `User` directly uses SCEVs in `Ops`.

bool	containsUndefs (const SCEV *S) const
	Return true if the SCEV expression contains an undef value.

bool	containsErasedValue (const SCEV *S) const
	Return true if the SCEV expression contains a Value that has been optimised out and is now a nullptr.

const SCEV *	getSCEV (Value *V)
	Return a SCEV expression for the full generality of the specified expression.

const SCEV *	getConstant (ConstantInt *V)

const SCEV *	getConstant (const APInt &Val)

const SCEV *	getConstant (Type *Ty, uint64_t V, bool isSigned=false)

const SCEV *	getLosslessPtrToIntExpr (const SCEV *Op, unsigned Depth=0)

const SCEV *	getPtrToIntExpr (const SCEV Op, Type Ty)

const SCEV *	getTruncateExpr (const SCEV Op, Type Ty, unsigned Depth=0)

const SCEV *	getVScale (Type *Ty)

const SCEV *	getZeroExtendExpr (const SCEV Op, Type Ty, unsigned Depth=0)

const SCEV *	getZeroExtendExprImpl (const SCEV Op, Type Ty, unsigned Depth=0)

const SCEV *	getSignExtendExpr (const SCEV Op, Type Ty, unsigned Depth=0)

const SCEV *	getSignExtendExprImpl (const SCEV Op, Type Ty, unsigned Depth=0)

const SCEV *	getCastExpr (SCEVTypes Kind, const SCEV Op, Type Ty)

const SCEV *	getAnyExtendExpr (const SCEV Op, Type Ty)
	getAnyExtendExpr - Return a SCEV for the given operand extended with unspecified bits out to the given type.

const SCEV *	getAddExpr (SmallVectorImpl< const SCEV * > &Ops, SCEV::NoWrapFlags Flags=SCEV::FlagAnyWrap, unsigned Depth=0)
	Get a canonical add expression, or something simpler if possible.

const SCEV *	getAddExpr (const SCEV LHS, const SCEV RHS, SCEV::NoWrapFlags Flags=SCEV::FlagAnyWrap, unsigned Depth=0)

const SCEV *	getAddExpr (const SCEV Op0, const SCEV Op1, const SCEV *Op2, SCEV::NoWrapFlags Flags=SCEV::FlagAnyWrap, unsigned Depth=0)

const SCEV *	getMulExpr (SmallVectorImpl< const SCEV * > &Ops, SCEV::NoWrapFlags Flags=SCEV::FlagAnyWrap, unsigned Depth=0)
	Get a canonical multiply expression, or something simpler if possible.

const SCEV *	getMulExpr (const SCEV LHS, const SCEV RHS, SCEV::NoWrapFlags Flags=SCEV::FlagAnyWrap, unsigned Depth=0)

const SCEV *	getMulExpr (const SCEV Op0, const SCEV Op1, const SCEV *Op2, SCEV::NoWrapFlags Flags=SCEV::FlagAnyWrap, unsigned Depth=0)

const SCEV *	getUDivExpr (const SCEV LHS, const SCEV RHS)
	Get a canonical unsigned division expression, or something simpler if possible.

const SCEV *	getUDivExactExpr (const SCEV LHS, const SCEV RHS)
	Get a canonical unsigned division expression, or something simpler if possible.

const SCEV *	getURemExpr (const SCEV LHS, const SCEV RHS)
	Represents an unsigned remainder expression based on unsigned division.

const SCEV *	getAddRecExpr (const SCEV Start, const SCEV Step, const Loop *L, SCEV::NoWrapFlags Flags)
	Get an add recurrence expression for the specified loop.

const SCEV *	getAddRecExpr (SmallVectorImpl< const SCEV * > &Operands, const Loop *L, SCEV::NoWrapFlags Flags)
	Get an add recurrence expression for the specified loop.

const SCEV *	getAddRecExpr (const SmallVectorImpl< const SCEV * > &Operands, const Loop *L, SCEV::NoWrapFlags Flags)

std::optional< std::pair< const SCEV , SmallVector< const SCEVPredicate , 3 > > >	createAddRecFromPHIWithCasts (const SCEVUnknown *SymbolicPHI)
	Checks if `SymbolicPHI` can be rewritten as an AddRecExpr under some Predicates.

const SCEV *	getGEPExpr (GEPOperator GEP, const SmallVectorImpl< const SCEV > &IndexExprs)
	Returns an expression for a GEP.

const SCEV *	getAbsExpr (const SCEV *Op, bool IsNSW)

const SCEV *	getMinMaxExpr (SCEVTypes Kind, SmallVectorImpl< const SCEV * > &Operands)

const SCEV *	getSequentialMinMaxExpr (SCEVTypes Kind, SmallVectorImpl< const SCEV * > &Operands)

const SCEV *	getSMaxExpr (const SCEV LHS, const SCEV RHS)

const SCEV *	getSMaxExpr (SmallVectorImpl< const SCEV * > &Operands)

const SCEV *	getUMaxExpr (const SCEV LHS, const SCEV RHS)

const SCEV *	getUMaxExpr (SmallVectorImpl< const SCEV * > &Operands)

const SCEV *	getSMinExpr (const SCEV LHS, const SCEV RHS)

const SCEV *	getSMinExpr (SmallVectorImpl< const SCEV * > &Operands)

const SCEV *	getUMinExpr (const SCEV LHS, const SCEV RHS, bool Sequential=false)

const SCEV *	getUMinExpr (SmallVectorImpl< const SCEV * > &Operands, bool Sequential=false)

const SCEV *	getUnknown (Value *V)

const SCEV *	getCouldNotCompute ()

const SCEV *	getZero (Type *Ty)
	Return a SCEV for the constant 0 of a specific type.

const SCEV *	getOne (Type *Ty)
	Return a SCEV for the constant 1 of a specific type.

const SCEV *	getPowerOfTwo (Type *Ty, unsigned Power)
	Return a SCEV for the constant `Power` of two.

const SCEV *	getMinusOne (Type *Ty)
	Return a SCEV for the constant -1 of a specific type.

const SCEV *	getSizeOfExpr (Type *IntTy, TypeSize Size)
	Return an expression for a TypeSize.

const SCEV *	getSizeOfExpr (Type IntTy, Type AllocTy)
	Return an expression for the alloc size of AllocTy that is type IntTy.

const SCEV *	getStoreSizeOfExpr (Type IntTy, Type StoreTy)
	Return an expression for the store size of StoreTy that is type IntTy.

const SCEV *	getOffsetOfExpr (Type IntTy, StructType STy, unsigned FieldNo)
	Return an expression for offsetof on the given field with type IntTy.

const SCEV *	getNegativeSCEV (const SCEV *V, SCEV::NoWrapFlags Flags=SCEV::FlagAnyWrap)
	Return the SCEV object corresponding to -V.

const SCEV *	getNotSCEV (const SCEV *V)
	Return the SCEV object corresponding to ~V.

const SCEV *	getMinusSCEV (const SCEV LHS, const SCEV RHS, SCEV::NoWrapFlags Flags=SCEV::FlagAnyWrap, unsigned Depth=0)
	Return LHS-RHS.

const SCEV *	getUDivCeilSCEV (const SCEV N, const SCEV D)
	Compute ceil(N / D).

const SCEV *	getTruncateOrZeroExtend (const SCEV V, Type Ty, unsigned Depth=0)
	Return a SCEV corresponding to a conversion of the input value to the specified type.

const SCEV *	getTruncateOrSignExtend (const SCEV V, Type Ty, unsigned Depth=0)
	Return a SCEV corresponding to a conversion of the input value to the specified type.

const SCEV *	getNoopOrZeroExtend (const SCEV V, Type Ty)
	Return a SCEV corresponding to a conversion of the input value to the specified type.

const SCEV *	getNoopOrSignExtend (const SCEV V, Type Ty)
	Return a SCEV corresponding to a conversion of the input value to the specified type.

const SCEV *	getNoopOrAnyExtend (const SCEV V, Type Ty)
	Return a SCEV corresponding to a conversion of the input value to the specified type.

const SCEV *	getTruncateOrNoop (const SCEV V, Type Ty)
	Return a SCEV corresponding to a conversion of the input value to the specified type.

const SCEV *	getUMaxFromMismatchedTypes (const SCEV LHS, const SCEV RHS)
	Promote the operands to the wider of the types using zero-extension, and then perform a umax operation with them.

const SCEV *	getUMinFromMismatchedTypes (const SCEV LHS, const SCEV RHS, bool Sequential=false)
	Promote the operands to the wider of the types using zero-extension, and then perform a umin operation with them.

const SCEV *	getUMinFromMismatchedTypes (SmallVectorImpl< const SCEV * > &Ops, bool Sequential=false)
	Promote the operands to the wider of the types using zero-extension, and then perform a umin operation with them.

const SCEV *	getPointerBase (const SCEV *V)
	Transitively follow the chain of pointer-type operands until reaching a SCEV that does not have a single pointer operand.

const SCEV *	removePointerBase (const SCEV *S)
	Compute an expression equivalent to S - getPointerBase(S).

const SCEV *	getSCEVAtScope (const SCEV S, const Loop L)
	Return a SCEV expression for the specified value at the specified scope in the program.

const SCEV *	getSCEVAtScope (Value V, const Loop L)
	This is a convenience function which does getSCEVAtScope(getSCEV(V), L).

bool	isLoopEntryGuardedByCond (const Loop L, ICmpInst::Predicate Pred, const SCEV LHS, const SCEV *RHS)
	Test whether entry to the loop is protected by a conditional between LHS and RHS.

bool	isBasicBlockEntryGuardedByCond (const BasicBlock BB, ICmpInst::Predicate Pred, const SCEV LHS, const SCEV *RHS)
	Test whether entry to the basic block is protected by a conditional between LHS and RHS.

bool	isLoopBackedgeGuardedByCond (const Loop L, ICmpInst::Predicate Pred, const SCEV LHS, const SCEV *RHS)
	Test whether the backedge of the loop is protected by a conditional between LHS and RHS.

const SCEV *	getTripCountFromExitCount (const SCEV *ExitCount)
	A version of getTripCountFromExitCount below which always picks an evaluation type which can not result in overflow.

const SCEV *	getTripCountFromExitCount (const SCEV ExitCount, Type EvalTy, const Loop *L)
	Convert from an "exit count" (i.e.

unsigned	getSmallConstantTripCount (const Loop *L)
	Returns the exact trip count of the loop if we can compute it, and the result is a small constant.

unsigned	getSmallConstantTripCount (const Loop L, const BasicBlock ExitingBlock)
	Return the exact trip count for this loop if we exit through ExitingBlock.

unsigned	getSmallConstantMaxTripCount (const Loop *L)
	Returns the upper bound of the loop trip count as a normal unsigned value.

const SCEV *	getConstantMaxTripCountFromArray (const Loop *L)
	Returns the upper bound of the loop trip count infered from array size.

unsigned	getSmallConstantTripMultiple (const Loop L, const SCEV ExitCount)
	Returns the largest constant divisor of the trip count as a normal unsigned value, if possible.

unsigned	getSmallConstantTripMultiple (const Loop *L)
	Returns the largest constant divisor of the trip count of the loop.

unsigned	getSmallConstantTripMultiple (const Loop L, const BasicBlock ExitingBlock)
	Returns the largest constant divisor of the trip count of this loop as a normal unsigned value, if possible.

const SCEV *	getExitCount (const Loop L, const BasicBlock ExitingBlock, ExitCountKind Kind=Exact)
	Return the number of times the backedge executes before the given exit would be taken; if not exactly computable, return SCEVCouldNotCompute.

const SCEV *	getBackedgeTakenCount (const Loop *L, ExitCountKind Kind=Exact)
	If the specified loop has a predictable backedge-taken count, return it, otherwise return a SCEVCouldNotCompute object.

const SCEV *	getPredicatedBackedgeTakenCount (const Loop L, SmallVector< const SCEVPredicate , 4 > &Predicates)
	Similar to getBackedgeTakenCount, except it will add a set of SCEV predicates to Predicates that are required to be true in order for the answer to be correct.

const SCEV *	getConstantMaxBackedgeTakenCount (const Loop *L)
	When successful, this returns a SCEVConstant that is greater than or equal to (i.e.

const SCEV *	getSymbolicMaxBackedgeTakenCount (const Loop *L)
	When successful, this returns a SCEV that is greater than or equal to (i.e.

bool	isBackedgeTakenCountMaxOrZero (const Loop *L)
	Return true if the backedge taken count is either the value returned by getConstantMaxBackedgeTakenCount or zero.

bool	hasLoopInvariantBackedgeTakenCount (const Loop *L)
	Return true if the specified loop has an analyzable loop-invariant backedge-taken count.

void	forgetAllLoops ()

void	forgetLoop (const Loop *L)
	This method should be called by the client when it has changed a loop in a way that may effect ScalarEvolution's ability to compute a trip count, or if the loop is deleted.

void	forgetTopmostLoop (const Loop *L)

void	forgetValue (Value *V)
	This method should be called by the client when it has changed a value in a way that may effect its value, or which may disconnect it from a def-use chain linking it to a loop.

void	forgetLoopDispositions ()
	Called when the client has changed the disposition of values in this loop.

void	forgetBlockAndLoopDispositions (Value *V=nullptr)
	Called when the client has changed the disposition of values in a loop or block.

uint32_t	getMinTrailingZeros (const SCEV *S)
	Determine the minimum number of zero bits that S is guaranteed to end in (at every loop iteration).

APInt	getConstantMultiple (const SCEV *S)
	Returns the max constant multiple of S.

APInt	getNonZeroConstantMultiple (const SCEV *S)

ConstantRange	getUnsignedRange (const SCEV *S)
	Determine the unsigned range for a particular SCEV.

APInt	getUnsignedRangeMin (const SCEV *S)
	Determine the min of the unsigned range for a particular SCEV.

APInt	getUnsignedRangeMax (const SCEV *S)
	Determine the max of the unsigned range for a particular SCEV.

ConstantRange	getSignedRange (const SCEV *S)
	Determine the signed range for a particular SCEV.

APInt	getSignedRangeMin (const SCEV *S)
	Determine the min of the signed range for a particular SCEV.

APInt	getSignedRangeMax (const SCEV *S)
	Determine the max of the signed range for a particular SCEV.

bool	isKnownNegative (const SCEV *S)
	Test if the given expression is known to be negative.

bool	isKnownPositive (const SCEV *S)
	Test if the given expression is known to be positive.

bool	isKnownNonNegative (const SCEV *S)
	Test if the given expression is known to be non-negative.

bool	isKnownNonPositive (const SCEV *S)
	Test if the given expression is known to be non-positive.

bool	isKnownNonZero (const SCEV *S)
	Test if the given expression is known to be non-zero.

std::pair< const SCEV , const SCEV >	SplitIntoInitAndPostInc (const Loop L, const SCEV S)
	Splits SCEV expression `S` into two SCEVs.

bool	isKnownViaInduction (ICmpInst::Predicate Pred, const SCEV LHS, const SCEV RHS)
	We'd like to check the predicate on every iteration of the most dominated loop between loops used in LHS and RHS.

bool	isKnownPredicate (ICmpInst::Predicate Pred, const SCEV LHS, const SCEV RHS)
	Test if the given expression is known to satisfy the condition described by Pred, LHS, and RHS.

std::optional< bool >	evaluatePredicate (ICmpInst::Predicate Pred, const SCEV LHS, const SCEV RHS)
	Check whether the condition described by Pred, LHS, and RHS is true or false.

bool	isKnownPredicateAt (ICmpInst::Predicate Pred, const SCEV LHS, const SCEV RHS, const Instruction *CtxI)
	Test if the given expression is known to satisfy the condition described by Pred, LHS, and RHS in the given Context.

std::optional< bool >	evaluatePredicateAt (ICmpInst::Predicate Pred, const SCEV LHS, const SCEV RHS, const Instruction *CtxI)
	Check whether the condition described by Pred, LHS, and RHS is true or false in the given `Context`.

bool	isKnownOnEveryIteration (ICmpInst::Predicate Pred, const SCEVAddRecExpr LHS, const SCEV RHS)
	Test if the condition described by Pred, LHS, RHS is known to be true on every iteration of the loop of the recurrency LHS.

ExitLimit	computeExitLimitFromCond (const Loop L, Value ExitCond, bool ExitIfTrue, bool ControlsOnlyExit, bool AllowPredicates=false)
	Compute the number of times the backedge of the specified loop will execute if its exit condition were a conditional branch of ExitCond.

std::optional< MonotonicPredicateType >	getMonotonicPredicateType (const SCEVAddRecExpr *LHS, ICmpInst::Predicate Pred)
	If, for all loop invariant X, the predicate "LHS `Pred` X" is monotonically increasing or decreasing, returns Some(MonotonicallyIncreasing) and Some(MonotonicallyDecreasing) respectively.

std::optional< LoopInvariantPredicate >	getLoopInvariantPredicate (ICmpInst::Predicate Pred, const SCEV LHS, const SCEV RHS, const Loop L, const Instruction CtxI=nullptr)
	If the result of the predicate LHS `Pred` RHS is loop invariant with respect to L, return a LoopInvariantPredicate with LHS and RHS being invariants, available at L's entry.

std::optional< LoopInvariantPredicate >	getLoopInvariantExitCondDuringFirstIterations (ICmpInst::Predicate Pred, const SCEV LHS, const SCEV RHS, const Loop L, const Instruction CtxI, const SCEV *MaxIter)
	If the result of the predicate LHS `Pred` RHS is loop invariant with respect to L at given Context during at least first MaxIter iterations, return a LoopInvariantPredicate with LHS and RHS being invariants, available at L's entry.

std::optional< LoopInvariantPredicate >	getLoopInvariantExitCondDuringFirstIterationsImpl (ICmpInst::Predicate Pred, const SCEV LHS, const SCEV RHS, const Loop L, const Instruction CtxI, const SCEV *MaxIter)

bool	SimplifyICmpOperands (ICmpInst::Predicate &Pred, const SCEV &LHS, const SCEV &RHS, unsigned Depth=0)
	Simplify LHS and RHS in a comparison with predicate Pred.

LoopDisposition	getLoopDisposition (const SCEV S, const Loop L)
	Return the "disposition" of the given SCEV with respect to the given loop.

bool	isLoopInvariant (const SCEV S, const Loop L)
	Return true if the value of the given SCEV is unchanging in the specified loop.

bool	isAvailableAtLoopEntry (const SCEV S, const Loop L)
	Determine if the SCEV can be evaluated at loop's entry.

bool	hasComputableLoopEvolution (const SCEV S, const Loop L)
	Return true if the given SCEV changes value in a known way in the specified loop.

BlockDisposition	getBlockDisposition (const SCEV S, const BasicBlock BB)
	Return the "disposition" of the given SCEV with respect to the given block.

bool	dominates (const SCEV S, const BasicBlock BB)
	Return true if elements that makes up the given SCEV dominate the specified basic block.

bool	properlyDominates (const SCEV S, const BasicBlock BB)
	Return true if elements that makes up the given SCEV properly dominate the specified basic block.

bool	hasOperand (const SCEV S, const SCEV Op) const
	Test whether the given SCEV has Op as a direct or indirect operand.

const SCEV *	getElementSize (Instruction *Inst)
	Return the size of an element read or written by Inst.

void	print (raw_ostream &OS) const

void	verify () const

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

const DataLayout &	getDataLayout () const
	Return the DataLayout associated with the module this SCEV instance is operating on.

const SCEVPredicate *	getEqualPredicate (const SCEV LHS, const SCEV RHS)

const SCEVPredicate *	getComparePredicate (ICmpInst::Predicate Pred, const SCEV LHS, const SCEV RHS)

const SCEVPredicate *	getWrapPredicate (const SCEVAddRecExpr *AR, SCEVWrapPredicate::IncrementWrapFlags AddedFlags)

const SCEV *	rewriteUsingPredicate (const SCEV S, const Loop L, const SCEVPredicate &A)
	Re-writes the SCEV according to the Predicates in `A`.

const SCEVAddRecExpr *	convertSCEVToAddRecWithPredicates (const SCEV S, const Loop L, SmallPtrSetImpl< const SCEVPredicate * > &Preds)
	Tries to convert the `S` expression to an AddRec expression, adding additional predicates to `Preds` as required.

std::optional< APInt >	computeConstantDifference (const SCEV LHS, const SCEV RHS)
	Compute `LHS` - `RHS` and returns the result as an APInt if it is a constant, and std::nullopt if it isn't.

void	setNoWrapFlags (SCEVAddRecExpr *AddRec, SCEV::NoWrapFlags Flags)
	Update no-wrap flags of an AddRec.

const SCEV *	applyLoopGuards (const SCEV Expr, const Loop L)
	Try to apply information from loop guards for `L` to `Expr`.

bool	loopHasNoAbnormalExits (const Loop *L)
	Return true if the loop has no abnormal exits.

bool	loopIsFiniteByAssumption (const Loop *L)
	Return true if this loop is finite by assumption.

Static Public Member Functions
static SCEV::NoWrapFlags	maskFlags (SCEV::NoWrapFlags Flags, int Mask)
	Convenient NoWrapFlags manipulation that hides enum casts and is visible in the ScalarEvolution name space.

static SCEV::NoWrapFlags	setFlags (SCEV::NoWrapFlags Flags, SCEV::NoWrapFlags OnFlags)

static SCEV::NoWrapFlags	clearFlags (SCEV::NoWrapFlags Flags, SCEV::NoWrapFlags OffFlags)

static bool	hasFlags (SCEV::NoWrapFlags Flags, SCEV::NoWrapFlags TestFlags)

Friends
class	ScalarEvolutionsTest

class	SCEVCallbackVH

class	SCEVExpander

class	SCEVUnknown

Detailed Description

The main scalar evolution driver.

Because client code (intentionally) can't do much with the SCEV objects directly, they must ask this class for services.

Definition at line 452 of file ScalarEvolution.h.

Member Enumeration Documentation

◆ BlockDisposition

enum llvm::ScalarEvolution::BlockDisposition

An enum describing the relationship between a SCEV and a basic block.

Enumerator
DoesNotDominateBlock	The SCEV does not dominate the block.
DominatesBlock	The SCEV dominates the block.
ProperlyDominatesBlock	The SCEV properly dominates the block.

Definition at line 464 of file ScalarEvolution.h.

◆ ExitCountKind

enum llvm::ScalarEvolution::ExitCountKind

The terms "backedge taken count" and "exit count" are used interchangeably to refer to the number of times the backedge of a loop has executed before the loop is exited.

Enumerator
Exact	An expression exactly describing the number of times the backedge has executed when a loop is exited.
ConstantMaximum	A constant which provides an upper bound on the exact trip count.
SymbolicMaximum	An expression which provides an upper bound on the exact trip count.

Definition at line 864 of file ScalarEvolution.h.

◆ LoopDisposition

enum llvm::ScalarEvolution::LoopDisposition

An enum describing the relationship between a SCEV and a loop.

Enumerator
LoopVariant	The SCEV is loop-variant (unknown).
LoopInvariant	The SCEV is loop-invariant.
LoopComputable	The SCEV varies predictably with the loop.

Definition at line 457 of file ScalarEvolution.h.

◆ MonotonicPredicateType

enum llvm::ScalarEvolution::MonotonicPredicateType

A predicate is said to be monotonically increasing if may go from being false to being true as the loop iterates, but never the other way around.

A predicate is said to be monotonically decreasing if may go from being true to being false as the loop iterates, but never the other way around.

Enumerator
MonotonicallyIncreasing
MonotonicallyDecreasing

Definition at line 1161 of file ScalarEvolution.h.

Constructor & Destructor Documentation

◆ ScalarEvolution() [1/2]

ScalarEvolution::ScalarEvolution	(	Function &	F,
		TargetLibraryInfo &	TLI,
		AssumptionCache &	AC,
		DominatorTree &	DT,
		LoopInfo &	LI
	)

Definition at line 13406 of file ScalarEvolution.cpp.

References F, and llvm::Intrinsic::getName().

◆ ScalarEvolution() [2/2]

ScalarEvolution::ScalarEvolution ( ScalarEvolution && Arg )

Definition at line 13427 of file ScalarEvolution.cpp.

References Arg.

◆ ~ScalarEvolution()

ScalarEvolution::~ScalarEvolution ( )

Definition at line 13458 of file ScalarEvolution.cpp.

References assert(), and llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::clear().

Member Function Documentation

◆ applyLoopGuards()

const SCEV * ScalarEvolution::applyLoopGuards	(	const SCEV *	Expr,
		const Loop *	L
	)

Try to apply information from loop guards for L to Expr.

Definition at line 15006 of file ScalarEvolution.cpp.

References llvm::append_range(), assert(), llvm::AssumptionCache::assumptions(), llvm::CallingConv::C, Cond, containsAddRecurrence(), llvm::DominatorTree::dominates(), llvm::SmallVectorImpl< T >::emplace_back(), llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::empty(), llvm::SmallVectorBase< Size_T >::empty(), llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::erase(), F, From, getAddExpr(), llvm::BranchInst::getCondition(), getConstant(), getMinMaxExpr(), getMinusSCEV(), getMulExpr(), llvm::Intrinsic::getName(), getOne(), getSCEV(), getSMaxExpr(), getSMinExpr(), llvm::BranchInst::getSuccessor(), llvm::CmpInst::getSwappedPredicate(), llvm::Value::getType(), getUDivExpr(), getUMaxExpr(), getUMinExpr(), getURemExpr(), llvm::SCEVConstant::getValue(), I, llvm::CmpInst::ICMP_EQ, llvm::CmpInst::ICMP_NE, llvm::CmpInst::ICMP_SGE, llvm::CmpInst::ICMP_SGT, llvm::CmpInst::ICMP_SLE, llvm::CmpInst::ICMP_SLT, llvm::CmpInst::ICMP_UGE, llvm::CmpInst::ICMP_UGT, llvm::CmpInst::ICMP_ULE, llvm::CmpInst::ICMP_ULT, llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::insert(), llvm::SmallPtrSetImpl< PtrType >::insert(), isKnownNonNegative(), llvm::Constant::isNullValue(), llvm::Type::isPointerTy(), llvm::BranchInst::isUnconditional(), llvm::APInt::isZero(), llvm::SCEV::isZero(), LHS, llvm::PatternMatch::m_LogicalAnd(), llvm::PatternMatch::m_LogicalOr(), llvm::PatternMatch::m_Value(), llvm::ConstantRange::makeExactICmpRegion(), llvm::PatternMatch::match(), llvm::Mul, llvm::SCEV::operands(), llvm::SmallVectorImpl< T >::pop_back_val(), llvm::SmallVectorTemplateBase< T, bool >::push_back(), llvm::reverse(), Rewriter, RHS, llvm::SmallVectorBase< Size_T >::size(), llvm::SMax, llvm::SMin, llvm::ConstantRange::sub(), std::swap(), llvm::UMax, llvm::UMin, and llvm::APInt::urem().

Referenced by llvm::LoopVectorizationCostModel::computeMaxVF(), and getSmallConstantTripMultiple().

◆ clearFlags()

static SCEV::NoWrapFlags llvm::ScalarEvolution::clearFlags	(	SCEV::NoWrapFlags	Flags,
		SCEV::NoWrapFlags	OffFlags
	)

inlinestatic

Definition at line 481 of file ScalarEvolution.h.

References Flags.

◆ computeConstantDifference()

std::optional< APInt > ScalarEvolution::computeConstantDifference	(	const SCEV *	LHS,
		const SCEV *	RHS
	)

Compute LHS - RHS and returns the result as an APInt if it is a constant, and std::nullopt if it isn't.

This is intended to be a cheaper version of getMinusSCEV. We can be frugal here since we just bail out of actually constructing and canonicalizing an expression in the cases where the result isn't going to be a constant.

Definition at line 11878 of file ScalarEvolution.cpp.

References Flags, llvm::SCEVConstant::getAPInt(), llvm::SCEV::getType(), and getTypeSizeInBits().

Referenced by SalvageDVI().

◆ computeExitLimitFromCond()

ScalarEvolution::ExitLimit ScalarEvolution::computeExitLimitFromCond	(	const Loop *	L,
		Value *	ExitCond,
		bool	ExitIfTrue,
		bool	ControlsOnlyExit,
		bool	AllowPredicates = `false`
	)

Compute the number of times the backedge of the specified loop will execute if its exit condition were a conditional branch of ExitCond.

ControlsOnlyExit is true if ExitCond directly controls the only exit branch. In this case, we can assume that the loop exits only if the condition is true and can infer that failing to meet the condition prior to integer wraparound results in undefined behavior.

If AllowPredicates is set, this call will try to use a minimal set of SCEV predicates in order to return an exact answer.

Definition at line 8860 of file ScalarEvolution.cpp.

Referenced by optimizeLoopExitWithUnknownExitCount().

◆ containsAddRecurrence()

bool ScalarEvolution::containsAddRecurrence ( const SCEV * S )

Return true if the SCEV is a scAddRecExpr or it contains scAddRecExpr.

The result will be cached in HasRecMap.

Definition at line 4440 of file ScalarEvolution.cpp.

References llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::end(), llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::find(), I, llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::insert(), and llvm::SCEVExprContains().

Referenced by applyLoopGuards().

◆ containsErasedValue()

bool ScalarEvolution::containsErasedValue ( const SCEV * S ) const

Return true if the SCEV expression contains a Value that has been optimised out and is now a nullptr.

Definition at line 13336 of file ScalarEvolution.cpp.

References llvm::SCEVUnknown::getValue(), and llvm::SCEVExprContains().

Referenced by SalvageDVI().

◆ containsUndefs()

bool ScalarEvolution::containsUndefs ( const SCEV * S ) const

Return true if the SCEV expression contains an undef value.

Definition at line 13327 of file ScalarEvolution.cpp.

References llvm::SCEVUnknown::getValue(), and llvm::SCEVExprContains().

Referenced by DbgGatherSalvagableDVI(), GetInductionVariable(), SalvageDVI(), and verify().

◆ convertSCEVToAddRecWithPredicates()

const SCEVAddRecExpr * ScalarEvolution::convertSCEVToAddRecWithPredicates	(	const SCEV *	S,
		const Loop *	L,
		SmallPtrSetImpl< const SCEVPredicate * > &	Preds
	)

Tries to convert the S expression to an AddRec expression, adding additional predicates to Preds as required.

Definition at line 14564 of file ScalarEvolution.cpp.

References llvm::SmallPtrSetImpl< PtrType >::insert(), and P.

Referenced by llvm::PredicatedScalarEvolution::getAsAddRec().

◆ createAddRecFromPHIWithCasts()

std::optional< std::pair< const SCEV *, SmallVector< const SCEVPredicate *, 3 > > > ScalarEvolution::createAddRecFromPHIWithCasts ( const SCEVUnknown * SymbolicPHI )

Checks if SymbolicPHI can be rewritten as an AddRecExpr under some Predicates.

If successful return these <AddRecExpr, Predicates>; The function is intended to be called from PSCEV (the caller will decide whether to actually add the predicates and carry out the rewrites).

Definition at line 5624 of file ScalarEvolution.cpp.

References assert(), llvm::SCEVUnknown::getValue(), I, and isIntegerLoopHeaderPHI().

◆ dominates()

bool ScalarEvolution::dominates	(	const SCEV *	S,
		const BasicBlock *	BB
	)

Return true if elements that makes up the given SCEV dominate the specified basic block.

Definition at line 13846 of file ScalarEvolution.cpp.

References DominatesBlock, and getBlockDisposition().

Referenced by llvm::SCEVExpander::isSafeToExpandAt().

◆ evaluatePredicate()

std::optional< bool > ScalarEvolution::evaluatePredicate	(	ICmpInst::Predicate	Pred,
		const SCEV *	LHS,
		const SCEV *	RHS
	)

Check whether the condition described by Pred, LHS, and RHS is true or false.

If we know it, return the evaluation of this condition. If neither is proved, return std::nullopt.

Definition at line 10885 of file ScalarEvolution.cpp.

References llvm::CmpInst::getInversePredicate(), isKnownPredicate(), LHS, and RHS.

Referenced by countToEliminateCompares(), and evaluatePredicateAt().

◆ evaluatePredicateAt()

std::optional< bool > ScalarEvolution::evaluatePredicateAt	(	ICmpInst::Predicate	Pred,
		const SCEV *	LHS,
		const SCEV *	RHS,
		const Instruction *	CtxI
	)

Check whether the condition described by Pred, LHS, and RHS is true or false in the given Context.

If we know it, return the evaluation of this condition. If neither is proved, return std::nullopt.

Definition at line 10904 of file ScalarEvolution.cpp.

References evaluatePredicate(), llvm::CmpInst::getInversePredicate(), llvm::Instruction::getParent(), isBasicBlockEntryGuardedByCond(), LHS, and RHS.

Referenced by createReplacement().

◆ forgetAllLoops()

void ScalarEvolution::forgetAllLoops ( )

Definition at line 8394 of file ScalarEvolution.cpp.

References llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::clear().

Referenced by llvm::UnrollLoop().

◆ forgetBlockAndLoopDispositions()

void ScalarEvolution::forgetBlockAndLoopDispositions ( Value * V = nullptr )

Called when the client has changed the disposition of values in a loop or block.

We don't have a way to invalidate per-loop/per-block dispositions. Clear and recompute is simpler.

Definition at line 8504 of file ScalarEvolution.cpp.

References llvm::SmallVectorBase< Size_T >::empty(), llvm::SmallPtrSetImpl< PtrType >::insert(), isSCEVable(), llvm::SmallVectorImpl< T >::pop_back_val(), llvm::SmallVectorTemplateBase< T, bool >::push_back(), and Users.

Referenced by llvm::breakLoopBackedge(), deleteDeadBlocksFromLoop(), llvm::deleteDeadLoop(), DoFlattenLoopPair(), llvm::Loop::makeLoopInvariant(), mergeBlocksIntoPredecessors(), moveInstructionBefore(), rebuildLoopAfterUnswitch(), sinkLoopInvariantInstructions(), llvm::UnrollAndJamLoop(), llvm::UnrollLoop(), unswitchNontrivialInvariants(), and unswitchTrivialBranch().

◆ forgetLoop()

void ScalarEvolution::forgetLoop ( const Loop * L )

This method should be called by the client when it has changed a loop in a way that may effect ScalarEvolution's ability to compute a trip count, or if the loop is deleted.

This call is potentially expensive for large loop bodies.

Definition at line 8441 of file ScalarEvolution.cpp.

References llvm::SmallVectorImpl< T >::append(), llvm::SmallVectorBase< Size_T >::empty(), llvm::SmallVectorTemplateCommon< T, typename >::end(), I, llvm::SmallVectorImpl< T >::insert(), llvm::SmallVectorImpl< T >::pop_back_val(), and PushLoopPHIs().

Referenced by llvm::breakLoopBackedge(), llvm::deleteDeadLoop(), deleteLoopIfDead(), DoFlattenLoopPair(), llvm::InnerLoopVectorizer::fixVectorizedLoop(), forgetTopmostLoop(), separateNestedLoop(), llvm::splitLoopBound(), llvm::UnrollAndJamLoop(), unswitchNontrivialInvariants(), unswitchTrivialBranch(), and unswitchTrivialSwitch().

◆ forgetLoopDispositions()

void ScalarEvolution::forgetLoopDispositions ( )

Called when the client has changed the disposition of values in this loop.

We don't have a way to invalidate per-loop dispositions. Clear and recompute is simpler.

Definition at line 8502 of file ScalarEvolution.cpp.

◆ forgetTopmostLoop()

void ScalarEvolution::forgetTopmostLoop ( const Loop * L )

Definition at line 8483 of file ScalarEvolution.cpp.

References forgetLoop().

Referenced by llvm::peelLoop(), llvm::simplifyLoop(), simplifyLoopCFG(), llvm::UnrollLoop(), llvm::UnrollRuntimeLoopRemainder(), unswitchNontrivialInvariants(), unswitchTrivialBranch(), and unswitchTrivialSwitch().

◆ forgetValue()

void ScalarEvolution::forgetValue ( Value * V )

This method should be called by the client when it has changed a value in a way that may effect its value, or which may disconnect it from a def-use chain linking it to a loop.

Definition at line 8487 of file ScalarEvolution.cpp.

References I, llvm::SmallPtrSetImpl< PtrType >::insert(), and llvm::SmallVectorTemplateBase< T, bool >::push_back().

Referenced by buildClonedLoopBlocks(), cloneLoopBlocks(), ConnectEpilog(), ConnectProlog(), llvm::formLCSSAForInstructions(), llvm::SCEVExpander::replaceCongruentIVs(), replaceLoopPHINodesWithPreheaderValues(), llvm::rewriteLoopExitValues(), RewriteUsesOfClonedInstructions(), simplifyOneLoop(), and llvm::UnrollLoop().

◆ getAbsExpr()

const SCEV * ScalarEvolution::getAbsExpr	(	const SCEV *	Op,
		bool	IsNSW
	)

Definition at line 3820 of file ScalarEvolution.cpp.

References llvm::SCEV::FlagAnyWrap, llvm::SCEV::FlagNSW, Flags, getNegativeSCEV(), and getSMaxExpr().

◆ getAddExpr() [1/3]

const SCEV * llvm::ScalarEvolution::getAddExpr	(	const SCEV *	LHS,
		const SCEV *	RHS,
		SCEV::NoWrapFlags	Flags = `SCEV::FlagAnyWrap`,
		unsigned	Depth = `0`
	)

inline

Definition at line 581 of file ScalarEvolution.h.

References llvm::Depth, Flags, getAddExpr(), LHS, and RHS.

◆ getAddExpr() [2/3]

const SCEV * llvm::ScalarEvolution::getAddExpr	(	const SCEV *	Op0,
		const SCEV *	Op1,
		const SCEV *	Op2,
		SCEV::NoWrapFlags	Flags = `SCEV::FlagAnyWrap`,
		unsigned	Depth = `0`
	)

inline

Definition at line 587 of file ScalarEvolution.h.

References llvm::Depth, Flags, and getAddExpr().

◆ getAddExpr() [3/3]

const SCEV * ScalarEvolution::getAddExpr	(	SmallVectorImpl< const SCEV * > &	Ops,
		SCEV::NoWrapFlags	Flags = `SCEV::FlagAnyWrap`,
		unsigned	Depth = `0`
	)

Get a canonical add expression, or something simpler if possible.

Definition at line 2514 of file ScalarEvolution.cpp.

References A, llvm::APInt::abs(), llvm::Add, AddOpsInlineThreshold, llvm::append_range(), assert(), B, llvm::SmallVectorTemplateCommon< T, typename >::begin(), llvm::BasicBlock::begin(), llvm::BitWidth, llvm::CallingConv::C, llvm::SmallVectorImpl< T >::clear(), CollectAddOperandsWithScales(), llvm::count_if(), llvm::Depth, llvm::DominatorTree::dominates(), llvm::SmallVectorBase< Size_T >::empty(), llvm::SmallVectorImpl< T >::erase(), llvm::SCEV::FlagAnyWrap, llvm::SCEV::FlagNSW, llvm::SCEV::FlagNUW, llvm::SCEV::FlagNW, Flags, getAddExpr(), getAddRecExpr(), getAnyExtendExpr(), getConstant(), getEffectiveSCEVType(), llvm::LoopBase< BlockT, LoopT >::getHeader(), llvm::SCEVAddRecExpr::getLoop(), getMulExpr(), llvm::SCEVNAryExpr::getNoWrapFlags(), llvm::SCEVNAryExpr::getNumOperands(), getOne(), llvm::SCEVNAryExpr::getOperand(), llvm::SCEVAddRecExpr::getStart(), getTruncateExpr(), getType(), getTypeSizeInBits(), getUDivExpr(), getZero(), GroupByComplexity(), hasFlags(), hasHugeExpression(), Idx, isAvailableAtLoopEntry(), llvm::APInt::isSignBitSet(), LHS, maskFlags(), MaxArithDepth, llvm::Mul, llvm::SCEVNAryExpr::operands(), llvm::SmallVectorTemplateBase< T, bool >::pop_back(), llvm::SmallVectorTemplateBase< T, bool >::push_back(), RHS, llvm::scAddExpr, llvm::scAddRecExpr, llvm::scMulExpr, setFlags(), llvm::SmallVectorBase< Size_T >::size(), StrengthenNoWrapFlags(), llvm::APInt::ule(), X, and Y.

Referenced by applyLoopGuards(), llvm::calculateUpperBound(), llvm::LoopVectorizationCostModel::computeMaxVF(), countToEliminateCompares(), createNodeForSelectViaUMinSeq(), llvm::SCEVAddRecExpr::evaluateAtIteration(), ExtractImmediate(), ExtractSymbol(), FactorOutConstant(), findForkedSCEVs(), getAddExpr(), getConstantMaxTripCountFromArray(), getExactSDiv(), getExtendAddRecStart(), getGEPExpr(), getLosslessPtrToIntExpr(), getMinusSCEV(), getMulExpr(), getNewAlignment(), llvm::SCEVAddRecExpr::getPostIncExpr(), getPreStartForExtend(), getSignExtendExprImpl(), getTripCountFromExitCount(), getTruncateExpr(), getUDivCeilSCEV(), getUDivExpr(), getZeroExtendExprImpl(), llvm::RuntimePointerChecking::insert(), llvm::ARMTTIImpl::isHardwareLoopProfitable(), IsIncrementNSW(), IsIncrementNUW(), isSafeDecreasingBound(), isSafeIncreasingBound(), removePointerBase(), SimplifyAddOperands(), SimplifyICmpOperands(), llvm::UnrollRuntimeLoopRemainder(), llvm::SCEVRewriteVisitor< SC >::visitAddExpr(), llvm::SCEVDivision::visitAddExpr(), and willNotOverflow().

◆ getAddRecExpr() [1/3]

const SCEV * ScalarEvolution::getAddRecExpr	(	const SCEV *	Start,
		const SCEV *	Step,
		const Loop *	L,
		SCEV::NoWrapFlags	Flags
	)

Get an add recurrence expression for the specified loop.

Simplify the expression as much as possible.

Definition at line 3641 of file ScalarEvolution.cpp.

References llvm::append_range(), llvm::SCEV::FlagNW, Flags, getAddRecExpr(), maskFlags(), and Operands.

Referenced by CollectSubexprs(), DoInitialMatch(), ExtractImmediate(), ExtractSymbol(), FactorOutConstant(), getAddExpr(), getAddRecExpr(), getAnyExtendExpr(), getExactSDiv(), getMulExpr(), llvm::SCEVAddRecExpr::getNumIterationsInRange(), llvm::SCEVAddRecExpr::getPostIncExpr(), getPreStartForExtend(), getSignExtendExprImpl(), llvm::SCEVAddRecExpr::getStepRecurrence(), getTruncateExpr(), getUDivExpr(), getZeroExtendExprImpl(), isLoopBackedgeGuardedByCond(), removePointerBase(), SplitAddRecs(), llvm::SCEVRewriteVisitor< SC >::visitAddRecExpr(), llvm::SCEVLoopAddRecRewriter::visitAddRecExpr(), and llvm::SCEVDivision::visitAddRecExpr().

◆ getAddRecExpr() [2/3]

const SCEV * llvm::ScalarEvolution::getAddRecExpr	(	const SmallVectorImpl< const SCEV * > &	Operands,
		const Loop *	L,
		SCEV::NoWrapFlags	Flags
	)

inline

Definition at line 615 of file ScalarEvolution.h.

References Flags, getAddRecExpr(), and Operands.

◆ getAddRecExpr() [3/3]

const SCEV * ScalarEvolution::getAddRecExpr	(	SmallVectorImpl< const SCEV * > &	Operands,
		const Loop *	L,
		SCEV::NoWrapFlags	Flags
	)

Get an add recurrence expression for the specified loop.

Simplify the expression as much as possible.

Definition at line 3659 of file ScalarEvolution.cpp.

References llvm::all_of(), assert(), llvm::LoopBase< BlockT, LoopT >::contains(), llvm::DominatorTree::dominates(), llvm::SCEV::FlagAnyWrap, llvm::SCEV::FlagNW, Flags, getAddRecExpr(), getEffectiveSCEVType(), llvm::LoopBase< BlockT, LoopT >::getHeader(), llvm::LoopBase< BlockT, LoopT >::getLoopDepth(), getType(), isLoopInvariant(), maskFlags(), Operands, llvm::scAddRecExpr, and StrengthenNoWrapFlags().

◆ getAnyExtendExpr()

const SCEV * ScalarEvolution::getAnyExtendExpr	(	const SCEV *	Op,
		Type *	Ty
	)

getAnyExtendExpr - Return a SCEV for the given operand extended with unspecified bits out to the given type.

Definition at line 2168 of file ScalarEvolution.cpp.

References assert(), llvm::SCEV::FlagNW, getAddRecExpr(), getAnyExtendExpr(), getEffectiveSCEVType(), getSignExtendExpr(), getTruncateOrNoop(), llvm::SCEV::getType(), getTypeSizeInBits(), getZeroExtendExpr(), isSCEVable(), and llvm::SmallVectorTemplateBase< T, bool >::push_back().

Referenced by getAddExpr(), getAnyExtendExpr(), and getNoopOrAnyExtend().

◆ getBackedgeTakenCount()

const SCEV * ScalarEvolution::getBackedgeTakenCount	(	const Loop *	L,
		ExitCountKind	Kind = `Exact`
	)

If the specified loop has a predictable backedge-taken count, return it, otherwise return a SCEVCouldNotCompute object.

The backedge-taken count is the number of times the loop header will be branched to from within the loop, assuming there are no abnormal exists like exception throws. This is one less than the trip count of the loop, since it doesn't count the first iteration, when the header is branched to from outside the loop.

Note that it is not valid to call this method on a loop without a loop-invariant backedge-taken count (see hasLoopInvariantBackedgeTakenCount).

Definition at line 8305 of file ScalarEvolution.cpp.

References ConstantMaximum, Exact, llvm_unreachable, and SymbolicMaximum.

Referenced by breakBackedgeIfNotTaken(), canFoldTermCondOfLoop(), computeTripCount(), getConstantMaxBackedgeTakenCount(), getPreStartForExtend(), getSmallConstantTripCount(), getSymbolicMaxBackedgeTakenCount(), hasLoopInvariantBackedgeTakenCount(), llvm::ARMTTIImpl::isHardwareLoopProfitable(), llvm::IVUsers::print(), PrintLoopInfo(), verify(), and verifyTripCount().

◆ getBlockDisposition()

ScalarEvolution::BlockDisposition ScalarEvolution::getBlockDisposition	(	const SCEV *	S,
		const BasicBlock *	BB
	)

Return the "disposition" of the given SCEV with respect to the given block.

Definition at line 13772 of file ScalarEvolution.cpp.

References D, DoesNotDominateBlock, and llvm::reverse().

Referenced by dominates(), properlyDominates(), and verify().

◆ getCastExpr()

const SCEV * ScalarEvolution::getCastExpr	(	SCEVTypes	Kind,
		const SCEV *	Op,
		Type *	Ty
	)

Definition at line 2150 of file ScalarEvolution.cpp.

References getPtrToIntExpr(), getSignExtendExpr(), getTruncateExpr(), getZeroExtendExpr(), llvm_unreachable, llvm::scPtrToInt, llvm::scSignExtend, llvm::scTruncate, and llvm::scZeroExtend.

◆ getComparePredicate()

const SCEVPredicate * ScalarEvolution::getComparePredicate	(	ICmpInst::Predicate	Pred,
		const SCEV *	LHS,
		const SCEV *	RHS
	)

Definition at line 14399 of file ScalarEvolution.cpp.

References assert(), llvm::Value::getType(), LHS, llvm::SCEVPredicate::P_Compare, and RHS.

Referenced by getEqualPredicate().

◆ getConstant() [1/3]

const SCEV * ScalarEvolution::getConstant ( const APInt & Val )

Definition at line 489 of file ScalarEvolution.cpp.

References llvm::ConstantInt::get(), getConstant(), and getContext().

◆ getConstant() [2/3]

const SCEV * ScalarEvolution::getConstant ( ConstantInt * V )

Definition at line 478 of file ScalarEvolution.cpp.

References llvm::scConstant.

Referenced by applyLoopGuards(), BinomialCoefficient(), llvm::calculateUpperBound(), llvm::cannotBeMaxInLoop(), llvm::cannotBeMinInLoop(), CollectSubexprs(), llvm::LoopVectorizationCostModel::computeMaxVF(), llvm::IndexedReference::computeRefCost(), computeTripCount(), countToEliminateCompares(), DoInitialMatch(), EvaluateConstantChrecAtConstant(), ExtractImmediate(), ExtractSymbol(), FactorOutConstant(), getAddExpr(), getConstant(), getConstantMaxTripCountFromArray(), getExactSDiv(), getMinMaxExpr(), getMinusOne(), getMulExpr(), getNegativeSCEV(), getNotSCEV(), llvm::SCEVAddRecExpr::getNumIterationsInRange(), getOffsetOfExpr(), getOne(), getPowerOfTwo(), getSignedOverflowLimitForStep(), getSignExtendExprImpl(), getSizeOfExpr(), getTruncateExpr(), getUDivExactExpr(), getUDivExpr(), getUnsignedOverflowLimitForStep(), getZero(), getZeroExtendExprImpl(), llvm::InductionDescriptor::isInductionPHI(), isSafeDecreasingBound(), isSafeDependenceDistance(), isSafeIncreasingBound(), llvm::VPlanTransforms::optimizeForVFAndUF(), SimplifyAddOperands(), SimplifyICmpOperands(), SolveLinEquationWithOverflow(), SplitAddRecs(), llvm::UnrolledInstAnalyzer::UnrolledInstAnalyzer(), llvm::UnrollRuntimeLoopRemainder(), verify(), llvm::SCEVDivision::visitConstant(), and willNotOverflow().

◆ getConstant() [3/3]

const SCEV * ScalarEvolution::getConstant	(	Type *	Ty,
		uint64_t	V,
		bool	isSigned = `false`
	)

Definition at line 494 of file ScalarEvolution.cpp.

References llvm::ConstantInt::get(), getConstant(), getEffectiveSCEVType(), and isSigned().

◆ getConstantMaxBackedgeTakenCount()

const SCEV * llvm::ScalarEvolution::getConstantMaxBackedgeTakenCount ( const Loop * L )

inline

When successful, this returns a SCEVConstant that is greater than or equal to (i.e.

a "conservative over-approximation") of the value returend by getBackedgeTakenCount. If such a value cannot be computed, it returns the SCEVCouldNotCompute object.

Definition at line 906 of file ScalarEvolution.h.

References ConstantMaximum, and getBackedgeTakenCount().

Referenced by breakBackedgeIfNotTaken(), countToEliminateCompares(), getSignExtendExprImpl(), getSmallConstantMaxTripCount(), getZeroExtendExprImpl(), isLoopDead(), mustBeFiniteCountedLoop(), and PrintLoopInfo().

◆ getConstantMaxTripCountFromArray()

const SCEV * ScalarEvolution::getConstantMaxTripCountFromArray ( const Loop * L )

Returns the upper bound of the loop trip count infered from array size.

Can not access bytes starting outside the statically allocated size without being immediate UB. Returns SCEVCouldNotCompute if the trip count could not inferred from array accesses.

Definition at line 8113 of file ScalarEvolution.cpp.

References assert(), DL, llvm::DominatorTree::dominates(), GEP, getAddExpr(), llvm::AllocaInst::getAllocatedType(), llvm::AllocaInst::getArraySize(), getConstant(), getCouldNotCompute(), getDataLayout(), getElementSize(), llvm::getLoadStorePointerOperand(), getOne(), llvm::Instruction::getParent(), getPointerBase(), getSCEV(), llvm::SCEVAddRecExpr::getStart(), llvm::SCEVAddRecExpr::getStepRecurrence(), llvm::SCEV::getType(), getUDivCeilSCEV(), getUMinFromMismatchedTypes(), isLoopInvariant(), llvm::SCEV::isZero(), llvm::SmallVectorTemplateBase< T, bool >::push_back(), and llvm::SmallVectorBase< Size_T >::size().

◆ getConstantMultiple()

APInt ScalarEvolution::getConstantMultiple ( const SCEV * S )

Returns the max constant multiple of S.

Definition at line 6304 of file ScalarEvolution.cpp.

References assert(), and I.

Referenced by getMinTrailingZeros(), getNonZeroConstantMultiple(), and verify().

◆ getContext()

LLVMContext & llvm::ScalarEvolution::getContext ( ) const

inline

◆ getCouldNotCompute()

const SCEV * ScalarEvolution::getCouldNotCompute ( )

Definition at line 4427 of file ScalarEvolution.cpp.

Referenced by BinomialCoefficient(), getConstantMaxTripCountFromArray(), getLosslessPtrToIntExpr(), getMinAnalyzeableBackedgeTakenCount(), getMinusSCEV(), llvm::SCEVAddRecExpr::getNumIterationsInRange(), getSmallConstantTripMultiple(), getTripCountFromExitCount(), isKnownViaInduction(), isLoopBackedgeGuardedByCond(), SolveLinEquationWithOverflow(), SplitIntoInitAndPostInc(), and verify().

◆ getDataLayout()

const DataLayout & llvm::ScalarEvolution::getDataLayout ( ) const

inline

Return the DataLayout associated with the module this SCEV instance is operating on.

Definition at line 1260 of file ScalarEvolution.h.

References llvm::Module::getDataLayout(), and llvm::GlobalValue::getParent().

Referenced by getConstantMaxTripCountFromArray(), getEffectiveSCEVType(), getLosslessPtrToIntExpr(), getOffsetOfExpr(), getSizeOfExpr(), getStoreSizeOfExpr(), getTypeSizeInBits(), and llvm::simplifyLoopIVs().

◆ getEffectiveSCEVType()

Type * ScalarEvolution::getEffectiveSCEVType ( Type * Ty ) const

Return a type with the same bitwidth as the given type and which represents how SCEV will treat the given type, for which isSCEVable must return true.

For pointer types, this is the pointer-sized integer type.

For pointer types, this is the pointer index sized integer type.

Definition at line 4397 of file ScalarEvolution.cpp.

References assert(), getDataLayout(), llvm::DataLayout::getIndexType(), llvm::Type::isIntegerTy(), llvm::Type::isPointerTy(), and isSCEVable().

Referenced by canBeCheaplyTransformed(), canComputePointerDiff(), DoInitialMatch(), findForkedSCEVs(), getAddExpr(), getAddRecExpr(), getAnyExtendExpr(), getConstant(), getElementSize(), getGEPExpr(), getLosslessPtrToIntExpr(), getMinMaxExpr(), getNegativeSCEV(), getNewAlignment(), getNotSCEV(), getSequentialMinMaxExpr(), getSignExtendExpr(), getSignExtendExprImpl(), getTruncateExpr(), getURemExpr(), getZeroExtendExpr(), isExistingPhi(), and visitIVCast().

◆ getElementSize()

const SCEV * ScalarEvolution::getElementSize ( Instruction * Inst )

Return the size of an element read or written by Inst.

Definition at line 13345 of file ScalarEvolution.cpp.

References getEffectiveSCEVType(), getSizeOfExpr(), and llvm::PointerType::getUnqual().

Referenced by getConstantMaxTripCountFromArray().

◆ getEqualPredicate()

const SCEVPredicate * ScalarEvolution::getEqualPredicate	(	const SCEV *	LHS,
		const SCEV *	RHS
	)

Definition at line 14393 of file ScalarEvolution.cpp.

References getComparePredicate(), llvm::CmpInst::ICMP_EQ, LHS, and RHS.

Referenced by llvm::PredicatedScalarEvolution::areAddRecsEqualWithPreds(), and llvm::replaceSymbolicStrideSCEV().

◆ getExitCount()

const SCEV * ScalarEvolution::getExitCount	(	const Loop *	L,
		const BasicBlock *	ExitingBlock,
		ExitCountKind	Kind = `Exact`
	)

Return the number of times the backedge executes before the given exit would be taken; if not exactly computable, return SCEVCouldNotCompute.

For a single exit loop, this value is equivelent to the result of getBackedgeTakenCount. The loop is guaranteed to exit (via some exit) before the backedge is executed (ExitCount + 1) times. Note that there is no guarantee about which exit is taken on the exiting iteration.

Definition at line 8285 of file ScalarEvolution.cpp.

References ConstantMaximum, Exact, llvm_unreachable, and SymbolicMaximum.

Referenced by llvm::calculateUpperBound(), getMinAnalyzeableBackedgeTakenCount(), getNarrowestLatchMaxTakenCountEstimate(), getSmallConstantTripCount(), getSmallConstantTripMultiple(), llvm::hasIterationCountInvariantInParent(), llvm::HardwareLoopInfo::isHardwareLoopCandidate(), mustBeFiniteCountedLoop(), optimizeLoopExitWithUnknownExitCount(), PrintLoopInfo(), llvm::rewriteLoopExitValues(), and llvm::UnrollRuntimeLoopRemainder().

◆ getGEPExpr()

const SCEV * ScalarEvolution::getGEPExpr	(	GEPOperator *	GEP,
		const SmallVectorImpl< const SCEV * > &	IndexExprs
	)

Returns an expression for a GEP.

GEP The GEP. The indices contained in the GEP itself are ignored, instead we use IndexExprs. IndexExprs The expressions for the indices.

Definition at line 3736 of file ScalarEvolution.cpp.

References assert(), llvm::SCEV::FlagAnyWrap, llvm::SCEV::FlagNSW, llvm::SCEV::FlagNUW, GEP, getAddExpr(), getEffectiveSCEVType(), getMulExpr(), getOffsetOfExpr(), getSCEV(), getSizeOfExpr(), getTruncateOrSignExtend(), llvm::SCEV::getType(), llvm::GetElementPtrInst::getTypeAtIndex(), llvm::ConstantInt::getValue(), llvm::APInt::getZExtValue(), isKnownNonNegative(), and llvm::Offset.

◆ getLoopDisposition()

ScalarEvolution::LoopDisposition ScalarEvolution::getLoopDisposition	(	const SCEV *	S,
		const Loop *	L
	)

Return the "disposition" of the given SCEV with respect to the given loop.

Definition at line 13673 of file ScalarEvolution.cpp.

References D, LoopVariant, and llvm::reverse().

Referenced by hasComputableLoopEvolution(), llvm::hasIterationCountInvariantInParent(), isLoopInvariant(), print(), and verify().

◆ getLoopInvariantExitCondDuringFirstIterations()

std::optional< ScalarEvolution::LoopInvariantPredicate > ScalarEvolution::getLoopInvariantExitCondDuringFirstIterations	(	ICmpInst::Predicate	Pred,
		const SCEV *	LHS,
		const SCEV *	RHS,
		const Loop *	L,
		const Instruction *	CtxI,
		const SCEV *	MaxIter
	)

If the result of the predicate LHS Pred RHS is loop invariant with respect to L at given Context during at least first MaxIter iterations, return a LoopInvariantPredicate with LHS and RHS being invariants, available at L's entry.

Otherwise, return std::nullopt. The predicate should be the loop's exit condition.

Definition at line 11077 of file ScalarEvolution.cpp.

References getLoopInvariantExitCondDuringFirstIterationsImpl(), LHS, RHS, and llvm::UMin.

Referenced by createReplacement().

◆ getLoopInvariantExitCondDuringFirstIterationsImpl()

std::optional< ScalarEvolution::LoopInvariantPredicate > ScalarEvolution::getLoopInvariantExitCondDuringFirstIterationsImpl	(	ICmpInst::Predicate	Pred,
		const SCEV *	LHS,
		const SCEV *	RHS,
		const Loop *	L,
		const Instruction *	CtxI,
		const SCEV *	MaxIter
	)

◆ getLoopInvariantPredicate()

std::optional< ScalarEvolution::LoopInvariantPredicate > ScalarEvolution::getLoopInvariantPredicate	(	ICmpInst::Predicate	Pred,
		const SCEV *	LHS,
		const SCEV *	RHS,
		const Loop *	L,
		const Instruction *	CtxI = `nullptr`
	)

If the result of the predicate LHS Pred RHS is loop invariant with respect to L, return a LoopInvariantPredicate with LHS and RHS being invariants, available at L's entry.

Otherwise, return std::nullopt.

Definition at line 10991 of file ScalarEvolution.cpp.

References assert(), llvm::CmpInst::getFlippedSignednessPredicate(), llvm::CmpInst::getInversePredicate(), llvm::SCEVAddRecExpr::getLoop(), getMonotonicPredicateType(), llvm::SCEVAddRecExpr::getStart(), llvm::SCEVAddRecExpr::getStepRecurrence(), llvm::CmpInst::getSwappedPredicate(), llvm::SCEVNAryExpr::hasNoSignedWrap(), llvm::SCEVNAryExpr::hasNoUnsignedWrap(), llvm::CmpInst::ICMP_ULE, llvm::CmpInst::ICMP_ULT, llvm::SCEVAddRecExpr::isAffine(), isKnownNonNegative(), isKnownPositive(), isKnownPredicateAt(), isLoopBackedgeGuardedByCond(), isLoopInvariant(), LHS, MonotonicallyIncreasing, P, RHS, and std::swap().

◆ getLosslessPtrToIntExpr()

const SCEV * ScalarEvolution::getLosslessPtrToIntExpr	(	const SCEV *	Op,
		unsigned	Depth = `0`
	)

The SCEVPtrToIntSinkingRewriter takes a scalar evolution expression, which computes a pointer-typed value, and rewrites the whole expression tree so that all the computations are done on integers, and the only pointer-typed operands in the expression are SCEVUnknown.

Definition at line 998 of file ScalarEvolution.cpp.

References assert(), llvm::sampleprof::Base, llvm::Depth, getAddExpr(), getCouldNotCompute(), getDataLayout(), getEffectiveSCEVType(), llvm::DataLayout::getIntPtrType(), getLosslessPtrToIntExpr(), getMulExpr(), llvm::SCEVNAryExpr::getNoWrapFlags(), llvm::SCEV::getType(), llvm::SCEVUnknown::getType(), getTypeSizeInBits(), getZero(), llvm::Type::isIntegerTy(), llvm::Type::isPointerTy(), llvm::SCEVNAryExpr::operands(), Operands, registerUser(), rewrite(), Rewriter, and llvm::scPtrToInt.

Referenced by getLosslessPtrToIntExpr(), and getPtrToIntExpr().

◆ getMinMaxExpr()

const SCEV * ScalarEvolution::getMinMaxExpr	(	SCEVTypes	Kind,
		SmallVectorImpl< const SCEV * > &	Operands
	)

Definition at line 3825 of file ScalarEvolution.cpp.

References llvm::BumpPtrAllocatorImpl< AllocatorT, SlabSize, SizeThreshold, GrowthDelay >::Allocate(), llvm::append_range(), assert(), llvm::SmallVectorTemplateCommon< T, typename >::begin(), llvm::SmallVectorBase< Size_T >::empty(), llvm::SmallVectorTemplateCommon< T, typename >::end(), llvm::SmallVectorImpl< T >::erase(), llvm::ConstantInt::get(), getConstant(), getContext(), getEffectiveSCEVType(), getMinMaxExpr(), getType(), GroupByComplexity(), llvm::CmpInst::ICMP_SGE, llvm::CmpInst::ICMP_SLE, llvm::CmpInst::ICMP_UGE, llvm::CmpInst::ICMP_ULE, Idx, LHS, llvm_unreachable, llvm::SCEVNAryExpr::operands(), registerUser(), RHS, llvm::scSMaxExpr, llvm::scSMinExpr, llvm::scUMaxExpr, llvm::scUMinExpr, llvm::SmallVectorBase< Size_T >::size(), llvm::APIntOps::smax(), llvm::APIntOps::smin(), llvm::APIntOps::umax(), and llvm::APIntOps::umin().

Referenced by applyLoopGuards(), getMinMaxExpr(), getNotSCEV(), getSequentialMinMaxExpr(), getSMaxExpr(), getSMinExpr(), getUMaxExpr(), and getUMinExpr().

◆ getMinTrailingZeros()

uint32_t ScalarEvolution::getMinTrailingZeros ( const SCEV * S )

Determine the minimum number of zero bits that S is guaranteed to end in (at every loop iteration).

It is, at the same time, the minimum number of times S is divisible by 2. For example, given {4,+,8} it returns 2. If S is guaranteed to be 0, it returns the bitwidth of S.

Definition at line 6320 of file ScalarEvolution.cpp.

References llvm::countTrailingZeros(), getConstantMultiple(), llvm::SCEV::getType(), and getTypeSizeInBits().

Referenced by extractConstantWithoutWrapping(), getTruncateExpr(), and SolveLinEquationWithOverflow().

◆ getMinusOne()

const SCEV * llvm::ScalarEvolution::getMinusOne ( Type * Ty )

inline

Return a SCEV for the constant -1 of a specific type.

Definition at line 666 of file ScalarEvolution.h.

References getConstant().

Referenced by createReplacement(), getNegativeSCEV(), getNotSCEV(), and getTripCountFromExitCount().

◆ getMinusSCEV()

const SCEV * ScalarEvolution::getMinusSCEV	(	const SCEV *	LHS,
		const SCEV *	RHS,
		SCEV::NoWrapFlags	Flags = `SCEV::FlagAnyWrap`,
		unsigned	Depth = `0`
	)

Return LHS-RHS.

Minus is represented in SCEV as A+B*-1.

If the LHS and RHS are pointers which don't share a common base (according to getPointerBase()), this returns a SCEVCouldNotCompute. To compute the difference between two unrelated pointers, you can explicitly convert the arguments using getPtrToIntExpr(), for pointer types that support it.

Definition at line 4611 of file ScalarEvolution.cpp.

References llvm::Depth, llvm::SCEV::FlagAnyWrap, llvm::SCEV::FlagNSW, Flags, getAddExpr(), getCouldNotCompute(), getNegativeSCEV(), getPointerBase(), getSignedRangeMin(), llvm::Value::getType(), getZero(), hasFlags(), isKnownNonNegative(), llvm::APInt::isMinSignedValue(), llvm::Type::isPointerTy(), LHS, removePointerBase(), and RHS.

Referenced by llvm::SCEVAAResult::alias(), llvm::InterleavedAccessInfo::analyzeInterleaving(), applyLoopGuards(), BinomialCoefficient(), canBeCheaplyTransformed(), createNodeForSelectViaUMinSeq(), createReplacement(), findForkedSCEVs(), getMinFromExprs(), getNewAlignment(), getNotSCEV(), llvm::getPointersDiff(), getStartForNegStride(), getUDivCeilSCEV(), getURemExpr(), llvm::IndexedReference::hasSpacialReuse(), isSafeDecreasingBound(), isSafeDependenceDistance(), isSafeIncreasingBound(), IsSimplerBaseSCEVForTarget(), verify(), llvm::SCEVDivision::visitMulExpr(), and willNotOverflow().

◆ getMonotonicPredicateType()

std::optional< ScalarEvolution::MonotonicPredicateType > ScalarEvolution::getMonotonicPredicateType	(	const SCEVAddRecExpr *	LHS,
		ICmpInst::Predicate	Pred
	)

If, for all loop invariant X, the predicate "LHS `Pred` X" is monotonically increasing or decreasing, returns Some(MonotonicallyIncreasing) and Some(MonotonicallyDecreasing) respectively.

If we could not prove either of these facts, returns std::nullopt.

Definition at line 10928 of file ScalarEvolution.cpp.

References assert(), llvm::CmpInst::getSwappedPredicate(), and LHS.

Referenced by countToEliminateCompares(), getLoopInvariantPredicate(), and isSafeToTruncateWideIVType().

◆ getMulExpr() [1/3]

const SCEV * llvm::ScalarEvolution::getMulExpr	(	const SCEV *	LHS,
		const SCEV *	RHS,
		SCEV::NoWrapFlags	Flags = `SCEV::FlagAnyWrap`,
		unsigned	Depth = `0`
	)

inline

Definition at line 596 of file ScalarEvolution.h.

References llvm::Depth, Flags, getMulExpr(), LHS, and RHS.

◆ getMulExpr() [2/3]

const SCEV * llvm::ScalarEvolution::getMulExpr	(	const SCEV *	Op0,
		const SCEV *	Op1,
		const SCEV *	Op2,
		SCEV::NoWrapFlags	Flags = `SCEV::FlagAnyWrap`,
		unsigned	Depth = `0`
	)

inline

Definition at line 602 of file ScalarEvolution.h.

References llvm::Depth, Flags, and getMulExpr().

◆ getMulExpr() [3/3]

const SCEV * ScalarEvolution::getMulExpr	(	SmallVectorImpl< const SCEV * > &	Ops,
		SCEV::NoWrapFlags	Flags = `SCEV::FlagAnyWrap`,
		unsigned	Depth = `0`
	)

Get a canonical multiply expression, or something simpler if possible.

Definition at line 3109 of file ScalarEvolution.cpp.

References llvm::Add, llvm::append_range(), assert(), llvm::SmallVectorTemplateCommon< T, typename >::begin(), Choose(), containsConstantInAddMulChain(), llvm::Depth, llvm::SmallVectorBase< Size_T >::empty(), llvm::SmallVectorImpl< T >::erase(), llvm::SCEV::FlagAnyWrap, llvm::SCEV::FlagNSW, llvm::SCEV::FlagNUW, llvm::SCEV::FlagNW, Flags, getAddExpr(), getAddRecExpr(), getConstant(), llvm::SCEVAddRecExpr::getLoop(), getMulExpr(), llvm::SCEVNAryExpr::getNoWrapFlags(), llvm::SCEVNAryExpr::getNumOperands(), llvm::SCEVNAryExpr::getOperand(), llvm::APInt::getSignedMinValue(), getSignedRangeMin(), llvm::SCEVAddRecExpr::getType(), getType(), getTypeSizeInBits(), getZero(), GroupByComplexity(), hasFlags(), hasHugeExpression(), Idx, isAvailableAtLoopEntry(), llvm::Type::isPointerTy(), LHS, maskFlags(), MaxAddRecSize, MaxArithDepth, llvm::Mul, MulOpsInlineThreshold, llvm::SCEV::operands(), Operands, llvm::SmallVectorTemplateBase< T, bool >::push_back(), llvm::SmallVectorImpl< T >::reserve(), RHS, llvm::scAddRecExpr, llvm::scMulExpr, setFlags(), llvm::SmallVectorBase< Size_T >::size(), StrengthenNoWrapFlags(), and umul_ov().

Referenced by applyLoopGuards(), BinomialCoefficient(), CollectAddOperandsWithScales(), CollectSubexprs(), llvm::IndexedReference::computeRefCost(), DoInitialMatch(), llvm::SCEVAddRecExpr::evaluateAtIteration(), FactorOutConstant(), findArrayDimensionsRec(), findForkedSCEVs(), getAddExpr(), getExactSDiv(), getGEPExpr(), getLosslessPtrToIntExpr(), getMulExpr(), getNegativeSCEV(), getNumBytes(), getSignExtendExprImpl(), getSizeOfExpr(), getStartForNegStride(), getTruncateExpr(), getUDivExactExpr(), getUDivExpr(), getURemExpr(), getZeroExtendExprImpl(), isSafeDependenceDistance(), removeConstantFactors(), SolveLinEquationWithOverflow(), llvm::SCEVRewriteVisitor< SC >::visitMulExpr(), llvm::SCEVDivision::visitMulExpr(), and willNotOverflow().

◆ getNegativeSCEV()

const SCEV * ScalarEvolution::getNegativeSCEV	(	const SCEV *	V,
		SCEV::NoWrapFlags	Flags = `SCEV::FlagAnyWrap`
	)

Return the SCEV object corresponding to -V.

Return a SCEV corresponding to -V = -1*V.

Definition at line 4525 of file ScalarEvolution.cpp.

References Flags, getConstant(), getEffectiveSCEVType(), getMinusOne(), getMulExpr(), and llvm::ConstantExpr::getNeg().

Referenced by detectShiftUntilZeroIdiom(), llvm::SCEVExpander::generateOverflowCheck(), getAbsExpr(), getLoopInvariantExitCondDuringFirstIterationsImpl(), getMinusSCEV(), isOneDimensionalArray(), isSafeDependenceDistance(), and llvm::FullDependence::normalize().

◆ getNonZeroConstantMultiple()

APInt ScalarEvolution::getNonZeroConstantMultiple ( const SCEV * S )

Definition at line 6315 of file ScalarEvolution.cpp.

References llvm::APInt::getBitWidth(), and getConstantMultiple().

Referenced by getSmallConstantTripMultiple().

◆ getNoopOrAnyExtend()

const SCEV * ScalarEvolution::getNoopOrAnyExtend	(	const SCEV *	V,
		Type *	Ty
	)

Return a SCEV corresponding to a conversion of the input value to the specified type.

If the type must be extended, it is extended with unspecified bits. The conversion must not be narrowing.

Definition at line 4710 of file ScalarEvolution.cpp.

References assert(), getAnyExtendExpr(), getTypeSizeInBits(), and llvm::Type::isIntOrPtrTy().

Referenced by llvm::IndexedReference::computeRefCost().

◆ getNoopOrSignExtend()

const SCEV * ScalarEvolution::getNoopOrSignExtend	(	const SCEV *	V,
		Type *	Ty
	)

Return a SCEV corresponding to a conversion of the input value to the specified type.

If the type must be extended, it is sign extended. The conversion must not be narrowing.

Definition at line 4698 of file ScalarEvolution.cpp.

References assert(), getSignExtendExpr(), getTypeSizeInBits(), and llvm::Type::isIntOrPtrTy().

Referenced by getNewAlignment(), isSafeDependenceDistance(), and NoopOrExtend().

◆ getNoopOrZeroExtend()

const SCEV * ScalarEvolution::getNoopOrZeroExtend	(	const SCEV *	V,
		Type *	Ty
	)

Return a SCEV corresponding to a conversion of the input value to the specified type.

If the type must be extended, it is zero extended. The conversion must not be narrowing.

Definition at line 4686 of file ScalarEvolution.cpp.

References assert(), getTypeSizeInBits(), getZeroExtendExpr(), and llvm::Type::isIntOrPtrTy().

Referenced by llvm::IndexedReference::computeRefCost(), getUMaxFromMismatchedTypes(), getUMinFromMismatchedTypes(), NoopOrExtend(), and optimizeLoopExitWithUnknownExitCount().

◆ getNotSCEV()

const SCEV * ScalarEvolution::getNotSCEV ( const SCEV * V )

Return the SCEV object corresponding to ~V.

Return a SCEV corresponding to ~V = -1-V.

Definition at line 4552 of file ScalarEvolution.cpp.

References assert(), getConstant(), getEffectiveSCEVType(), getMinMaxExpr(), getMinusOne(), getMinusSCEV(), llvm::ConstantExpr::getNot(), MatchNotExpr(), llvm::SCEVMinMaxExpr::negate(), llvm::SCEV::operands(), and llvm::SmallVectorTemplateBase< T, bool >::push_back().

Referenced by createNodeForSelectViaUMinSeq().

◆ getOffsetOfExpr()

const SCEV * ScalarEvolution::getOffsetOfExpr	(	Type *	IntTy,
		StructType *	STy,
		unsigned	FieldNo
	)

Return an expression for offsetof on the given field with type IntTy.

Definition at line 4338 of file ScalarEvolution.cpp.

References assert(), getConstant(), getDataLayout(), llvm::StructLayout::getElementOffset(), llvm::StructLayout::getSizeInBits(), llvm::DataLayout::getStructLayout(), and llvm::details::FixedOrScalableQuantity< LeafTy, ValueTy >::isScalable().

Referenced by getGEPExpr().

◆ getOne()

const SCEV * llvm::ScalarEvolution::getOne ( Type * Ty )

inline

Return a SCEV for the constant 1 of a specific type.

Definition at line 657 of file ScalarEvolution.h.

References getConstant().

Referenced by applyLoopGuards(), llvm::calculateUpperBound(), llvm::LoopVectorizationCostModel::computeMaxVF(), createReplacement(), getAddExpr(), getConstantMaxTripCountFromArray(), getLoopInvariantExitCondDuringFirstIterationsImpl(), getTripCountFromExitCount(), getUDivCeilSCEV(), llvm::ARMTTIImpl::isHardwareLoopProfitable(), isLoopBackedgeGuardedByCond(), isSafeDecreasingBound(), isSafeIncreasingBound(), and llvm::replaceSymbolicStrideSCEV().

◆ getPointerBase()

const SCEV * ScalarEvolution::getPointerBase ( const SCEV * V )

Transitively follow the chain of pointer-type operands until reaching a SCEV that does not have a single pointer operand.

This returns a SCEVUnknown pointer for well-formed pointer-type expressions, but corner cases do exist.

Definition at line 4779 of file ScalarEvolution.cpp.

References llvm::Add, and assert().

Referenced by llvm::DependenceInfo::depends(), getConstantMaxTripCountFromArray(), getMinusSCEV(), and llvm::tryDelinearizeFixedSizeImpl().

◆ getPowerOfTwo()

const SCEV * llvm::ScalarEvolution::getPowerOfTwo	(	Type *	Ty,
		unsigned	Power
	)

inline

Return a SCEV for the constant Power of two.

Definition at line 660 of file ScalarEvolution.h.

References assert(), getConstant(), llvm::APInt::getOneBitSet(), and getTypeSizeInBits().

◆ getPredicatedBackedgeTakenCount()

const SCEV * ScalarEvolution::getPredicatedBackedgeTakenCount	(	const Loop *	L,
		SmallVector< const SCEVPredicate *, 4 > &	Predicates
	)

Similar to getBackedgeTakenCount, except it will add a set of SCEV predicates to Predicates that are required to be true in order for the answer to be correct.

Predicates can be checked with run-time checks and can be used to perform loop versioning.

Definition at line 8300 of file ScalarEvolution.cpp.

Referenced by llvm::SCEVExpander::generateOverflowCheck(), llvm::PredicatedScalarEvolution::getBackedgeTakenCount(), and PrintLoopInfo().

◆ getPtrToIntExpr()

const SCEV * ScalarEvolution::getPtrToIntExpr	(	const SCEV *	Op,
		Type *	Ty
	)

Definition at line 1122 of file ScalarEvolution.cpp.

References assert(), getLosslessPtrToIntExpr(), getTruncateOrZeroExtend(), and llvm::Type::isIntegerTy().

Referenced by getCastExpr(), and llvm::SCEVRewriteVisitor< SC >::visitPtrToIntExpr().

◆ getSCEV()

const SCEV * ScalarEvolution::getSCEV ( Value * V )

Return a SCEV expression for the full generality of the specified expression.

Return an existing SCEV if it exists, otherwise analyze the expression and create a new one.

Definition at line 4499 of file ScalarEvolution.cpp.

References assert(), isAlwaysUnknown(), and isSCEVable().

Referenced by llvm::RecurrenceDescriptor::AddReductionVar(), llvm::IVUsers::AddUsersIfInteresting(), llvm::SCEVAAResult::alias(), llvm::analyzeICmp(), applyLoopGuards(), canFoldTermCondOfLoop(), canOverlap(), canTailPredicateLoop(), countToEliminateCompares(), createNodeForSelectViaUMinSeq(), DbgGatherSalvagableDVI(), DbgRewriteSalvageableDVIs(), llvm::DependenceInfo::depends(), detectShiftUntilZeroIdiom(), DoInitialMatch(), llvm::AlignmentFromAssumptionsPass::extractAlignmentInfo(), findForkedSCEVs(), findIVOperand(), FindLoopCounter(), genLoopLimit(), getAddressAccessSCEV(), llvm::PredicatedScalarEvolution::getAsAddRec(), llvm::Loop::LoopBounds::getBounds(), getBoundsCheckCond(), getConstantMaxTripCountFromArray(), getFalkorUnrollingPreferences(), getGEPExpr(), llvm::getIndexExpressionsFromGEP(), GetInductionVariable(), getNewAlignment(), llvm::getPointersDiff(), llvm::SCEVExpander::getRelatedExistingExpansion(), llvm::IVUsers::getReplacementExpr(), llvm::PredicatedScalarEvolution::getSCEV(), getSCEVAtScope(), llvm::DependenceInfo::getSplitIteration(), getStrengthenedNoWrapFlagsFromBinOp(), getStrideFromPointer(), llvm::isDereferenceableAndAlignedInLoop(), isExistingPhi(), isHighCostExpansion(), llvm::InductionDescriptor::isInductionPHI(), llvm::LoopAccessInfo::isInvariant(), llvm::LoopVectorizationLegality::isInvariantAddressOfReduction(), isLoopCounter(), isProfitableChain(), isSimpleIVUser(), llvm::LoopVectorizationLegality::isUniform(), print(), llvm::PredicatedScalarEvolution::print(), llvm::AlignmentFromAssumptionsPass::processAssumption(), llvm::SCEVExpander::replaceCongruentIVs(), llvm::rewriteLoopExitValues(), llvm::splitLoopBound(), llvm::storeToSameAddress(), stripGetElementPtr(), verify(), and verifyTripCount().

◆ getSCEVAtScope() [1/2]

const SCEV * ScalarEvolution::getSCEVAtScope	(	const SCEV *	S,
		const Loop *	L
	)

Return a SCEV expression for the specified value at the specified scope in the program.

The L value specifies a loop nest to evaluate the expression at, where null is the top-level or a specified loop is immediately inside of the loop.

This method can be used to compute the exit value for a variable defined in a loop by querying what the value will hold in the parent loop.

In the case that a relevant loop exit value cannot be computed, the original value V is returned.

Definition at line 9706 of file ScalarEvolution.cpp.

References llvm::CallingConv::C, llvm::SmallVectorImpl< T >::emplace_back(), and llvm::reverse().

Referenced by computeUnrollAndJamCount(), createReplacement(), getSCEVAtScope(), isInteresting(), print(), and llvm::rewriteLoopExitValues().

◆ getSCEVAtScope() [2/2]

const SCEV * ScalarEvolution::getSCEVAtScope	(	Value *	V,
		const Loop *	L
	)

This is a convenience function which does getSCEVAtScope(getSCEV(V), L).

Definition at line 10054 of file ScalarEvolution.cpp.

References getSCEV(), and getSCEVAtScope().

◆ getSequentialMinMaxExpr()

const SCEV * ScalarEvolution::getSequentialMinMaxExpr	(	SCEVTypes	Kind,
		SmallVectorImpl< const SCEV * > &	Operands
	)

◆ getSignedRange()

ConstantRange llvm::ScalarEvolution::getSignedRange ( const SCEV * S )

inline

Determine the signed range for a particular SCEV.

NOTE: This returns a copy of the reference returned by getRangeRef.

Definition at line 994 of file ScalarEvolution.h.

Referenced by getSignExtendExprImpl(), print(), and StrengthenNoWrapFlags().

◆ getSignedRangeMax()

APInt llvm::ScalarEvolution::getSignedRangeMax ( const SCEV * S )

inline

Determine the max of the signed range for a particular SCEV.

Definition at line 1004 of file ScalarEvolution.h.

References llvm::ConstantRange::getSignedMax().

Referenced by getSignedOverflowLimitForStep(), isKnownNegative(), isKnownNonPositive(), and SimplifyICmpOperands().

◆ getSignedRangeMin()

APInt llvm::ScalarEvolution::getSignedRangeMin ( const SCEV * S )

inline

Determine the min of the signed range for a particular SCEV.

Definition at line 999 of file ScalarEvolution.h.

References llvm::ConstantRange::getSignedMin().

Referenced by getMinusSCEV(), getMulExpr(), getSignedOverflowLimitForStep(), getZeroExtendExprImpl(), isKnownNonNegative(), isKnownPositive(), and SimplifyICmpOperands().

◆ getSignExtendExpr()

const SCEV * ScalarEvolution::getSignExtendExpr	(	const SCEV *	Op,
		Type *	Ty,
		unsigned	Depth = `0`
	)

Definition at line 1884 of file ScalarEvolution.cpp.

References assert(), llvm::Depth, getEffectiveSCEVType(), getSignExtendExprImpl(), getTypeSizeInBits(), insertFoldCacheEntry(), isSCEVable(), and llvm::scSignExtend.

Referenced by getAnyExtendExpr(), getCastExpr(), getNoopOrSignExtend(), getSignExtendExprImpl(), getTruncateOrSignExtend(), getZeroExtendExprImpl(), isAddRecSExtable(), isAddSExtable(), IsIncrementNSW(), isMulSExtable(), llvm::SCEVRewriteVisitor< SC >::visitSignExtendExpr(), and willNotOverflow().

◆ getSignExtendExprImpl()

const SCEV * ScalarEvolution::getSignExtendExprImpl	(	const SCEV *	Op,
		Type *	Ty,
		unsigned	Depth = `0`
	)

Definition at line 1906 of file ScalarEvolution.cpp.

References assert(), llvm::BitWidth, llvm::CallingConv::C, llvm::ConstantRange::contains(), D, llvm::Depth, extractConstantWithoutWrapping(), llvm::SCEV::FlagAnyWrap, llvm::SCEV::FlagNSW, llvm::SCEV::FlagNUW, llvm::SCEV::FlagNW, llvm::IntegerType::get(), getAddExpr(), getAddRecExpr(), getConstant(), getConstantMaxBackedgeTakenCount(), getContext(), getEffectiveSCEVType(), getMulExpr(), llvm::ConstantExpr::getSExt(), getSignedRange(), getSignExtendExpr(), getSMaxExpr(), getSMinExpr(), getTruncateOrSignExtend(), getTruncateOrZeroExtend(), llvm::SCEV::getType(), getTypeSizeInBits(), getZeroExtendExpr(), isKnownNonNegative(), isSCEVable(), MaxCastDepth, Operands, llvm::SmallVectorTemplateBase< T, bool >::push_back(), registerUser(), llvm::scSignExtend, setNoWrapFlags(), llvm::ConstantRange::sextOrTrunc(), llvm::ConstantRange::signExtend(), llvm::ConstantRange::truncate(), and X.

Referenced by getSignExtendExpr().

◆ getSizeOfExpr() [1/2]

const SCEV * ScalarEvolution::getSizeOfExpr	(	Type *	IntTy,
		Type *	AllocTy
	)

Return an expression for the alloc size of AllocTy that is type IntTy.

Definition at line 4330 of file ScalarEvolution.cpp.

References getDataLayout(), and getSizeOfExpr().

◆ getSizeOfExpr() [2/2]

const SCEV * ScalarEvolution::getSizeOfExpr	(	Type *	IntTy,
		TypeSize	Size
	)

Return an expression for a TypeSize.

Definition at line 4323 of file ScalarEvolution.cpp.

References getConstant(), getMulExpr(), getVScale(), and Size.

Referenced by findForkedSCEVs(), getElementSize(), getGEPExpr(), getSizeOfExpr(), and getStoreSizeOfExpr().

◆ getSmallConstantMaxTripCount()

unsigned ScalarEvolution::getSmallConstantMaxTripCount ( const Loop * L )

Returns the upper bound of the loop trip count as a normal unsigned value.

Returns 0 if the trip count is unknown or not constant.

Definition at line 8107 of file ScalarEvolution.cpp.

References getConstantMaxBackedgeTakenCount(), and getConstantTripCount().

Referenced by llvm::HexagonTTIImpl::getPeelingPreferences(), getSmallBestKnownTC(), llvm::isDereferenceableAndAlignedInLoop(), tryToUnrollLoop(), and llvm::UnrollLoop().

◆ getSmallConstantTripCount() [1/2]

unsigned ScalarEvolution::getSmallConstantTripCount ( const Loop * L )

Returns the exact trip count of the loop if we can compute it, and the result is a small constant.

'0' is used to represent an unknown or non-constant trip count. Note that a trip count is simply one more than the backedge taken count for the loop.

Definition at line 8091 of file ScalarEvolution.cpp.

References Exact, getBackedgeTakenCount(), and getConstantTripCount().

Referenced by llvm::CacheCost::CacheCost(), llvm::LoopVectorizationCostModel::computeMaxVF(), llvm::HexagonTTIImpl::getPeelingPreferences(), getSmallBestKnownTC(), llvm::PPCTTIImpl::isHardwareLoopProfitable(), tryToUnrollAndJamLoop(), tryToUnrollLoop(), and llvm::UnrollLoop().

◆ getSmallConstantTripCount() [2/2]

unsigned ScalarEvolution::getSmallConstantTripCount	(	const Loop *	L,
		const BasicBlock *	ExitingBlock
	)

Return the exact trip count for this loop if we exit through ExitingBlock.

'0' is used to represent an unknown or non-constant trip count. Note that a trip count is simply one more than the backedge taken count for the same exit. This "trip count" assumes that control exits via ExitingBlock. More precisely, it is the number of times that control will reach ExitingBlock before taking the branch. For loops with multiple exits, it may not be the number times that the loop header executes if the loop exits prematurely via another branch.

Definition at line 8097 of file ScalarEvolution.cpp.

References assert(), getConstantTripCount(), and getExitCount().

◆ getSmallConstantTripMultiple() [1/3]

unsigned ScalarEvolution::getSmallConstantTripMultiple ( const Loop * L )

Returns the largest constant divisor of the trip count of the loop.

Will return 1 if no trip count could be computed, or if a divisor could not be found.

Definition at line 8233 of file ScalarEvolution.cpp.

References getSmallConstantTripMultiple().

◆ getSmallConstantTripMultiple() [2/3]

unsigned ScalarEvolution::getSmallConstantTripMultiple	(	const Loop *	L,
		const BasicBlock *	ExitingBlock
	)

Returns the largest constant divisor of the trip count of this loop as a normal unsigned value, if possible.

This means that the actual trip count is always a multiple of the returned value (don't forget the trip count could very well be zero as well!). As explained in the comments for getSmallConstantTripCount, this assumes that control exits the loop via ExitingBlock.

This means that the actual trip count is always a multiple of the returned value (don't forget the trip count could very well be zero as well!).

Returns 1 if the trip count is unknown or not guaranteed to be the multiple of a constant (which is also the case if the trip count is simply constant, use getSmallConstantTripCount for that case), Will also return 1 if the trip count is very large (>= 2^32).

As explained in the comments for getSmallConstantTripCount, this assumes that control exits the loop via ExitingBlock.

Definition at line 8276 of file ScalarEvolution.cpp.

References assert(), getExitCount(), and getSmallConstantTripMultiple().

◆ getSmallConstantTripMultiple() [3/3]

unsigned ScalarEvolution::getSmallConstantTripMultiple	(	const Loop *	L,
		const SCEV *	ExitCount
	)

Returns the largest constant divisor of the trip count as a normal unsigned value, if possible.

This means that the actual trip count is always a multiple of the returned value. Returns 1 if the trip count is unknown or not guaranteed to be the multiple of a constant., Will also return 1 if the trip count is very large (>= 2^32). Note that the argument is an exit count for loop L, NOT a trip count.

Definition at line 8247 of file ScalarEvolution.cpp.

References applyLoopGuards(), llvm::APInt::countTrailingZeros(), llvm::APInt::getActiveBits(), getCouldNotCompute(), getNonZeroConstantMultiple(), getTripCountFromExitCount(), llvm::APInt::getZExtValue(), and llvm::APInt::zextOrTrunc().

Referenced by getSmallConstantTripMultiple(), PrintLoopInfo(), tryToUnrollAndJamLoop(), tryToUnrollLoop(), and llvm::UnrollLoop().

◆ getSMaxExpr() [1/2]

const SCEV * ScalarEvolution::getSMaxExpr	(	const SCEV *	LHS,
		const SCEV *	RHS
	)

Definition at line 4282 of file ScalarEvolution.cpp.

References getSMaxExpr(), LHS, and RHS.

Referenced by applyLoopGuards(), getAbsExpr(), getSignExtendExprImpl(), getSMaxExpr(), IntersectSignedRange(), and llvm::SCEVRewriteVisitor< SC >::visitSMaxExpr().

◆ getSMaxExpr() [2/2]

const SCEV * ScalarEvolution::getSMaxExpr ( SmallVectorImpl< const SCEV * > & Operands )

Definition at line 4287 of file ScalarEvolution.cpp.

References getMinMaxExpr(), and llvm::scSMaxExpr.

◆ getSMinExpr() [1/2]

const SCEV * ScalarEvolution::getSMinExpr	(	const SCEV *	LHS,
		const SCEV *	RHS
	)

Definition at line 4300 of file ScalarEvolution.cpp.

References getSMinExpr(), LHS, and RHS.

Referenced by applyLoopGuards(), getSignExtendExprImpl(), getSMinExpr(), IntersectSignedRange(), llvm::splitLoopBound(), and llvm::SCEVRewriteVisitor< SC >::visitSMinExpr().

◆ getSMinExpr() [2/2]

const SCEV * ScalarEvolution::getSMinExpr ( SmallVectorImpl< const SCEV * > & Operands )

Definition at line 4306 of file ScalarEvolution.cpp.

References getMinMaxExpr(), and llvm::scSMinExpr.

◆ getStoreSizeOfExpr()

const SCEV * ScalarEvolution::getStoreSizeOfExpr	(	Type *	IntTy,
		Type *	StoreTy
	)

Return an expression for the store size of StoreTy that is type IntTy.

Definition at line 4334 of file ScalarEvolution.cpp.

References getDataLayout(), and getSizeOfExpr().

Referenced by llvm::RuntimePointerChecking::insert().

◆ getStrengthenedNoWrapFlagsFromBinOp()

std::optional< SCEV::NoWrapFlags > ScalarEvolution::getStrengthenedNoWrapFlagsFromBinOp ( const OverflowingBinaryOperator * OBO )

Parse NSW/NUW flags from add/sub/mul IR binary operation Op into SCEV no-wrap flags, and deduce flag[s] that aren't known yet.

Does not mutate the original instruction. Returns std::nullopt if it could not deduce more precise flags than the instruction already has, otherwise returns proven flags.

Definition at line 2379 of file ScalarEvolution.cpp.

References llvm::SCEV::FlagAnyWrap, llvm::SCEV::FlagNSW, llvm::SCEV::FlagNUW, Flags, llvm::Operator::getOpcode(), llvm::User::getOperand(), getSCEV(), llvm::OverflowingBinaryOperator::hasNoSignedWrap(), llvm::OverflowingBinaryOperator::hasNoUnsignedWrap(), LHS, RHS, setFlags(), UseContextForNoWrapFlagInference, and willNotOverflow().

Referenced by llvm::SCEVExpander::hoistIVInc().

◆ getSymbolicMaxBackedgeTakenCount()

const SCEV * llvm::ScalarEvolution::getSymbolicMaxBackedgeTakenCount ( const Loop * L )

inline

When successful, this returns a SCEV that is greater than or equal to (i.e.

a "conservative over-approximation") of the value returend by getBackedgeTakenCount. If such a value cannot be computed, it returns the SCEVCouldNotCompute object.

Definition at line 914 of file ScalarEvolution.h.

References getBackedgeTakenCount(), and SymbolicMaximum.

Referenced by getNarrowestLatchMaxTakenCountEstimate(), and PrintLoopInfo().

◆ getTripCountFromExitCount() [1/2]

const SCEV * ScalarEvolution::getTripCountFromExitCount ( const SCEV * ExitCount )

A version of getTripCountFromExitCount below which always picks an evaluation type which can not result in overflow.

Definition at line 8036 of file ScalarEvolution.cpp.

References assert(), getCouldNotCompute(), llvm::Type::getIntNTy(), getTripCountFromExitCount(), and llvm::SCEV::getType().

Referenced by computeTripCount(), llvm::createTripCountSCEV(), getNumBytes(), getSmallConstantTripMultiple(), getTripCountFromExitCount(), and verifyTripCount().

◆ getTripCountFromExitCount() [2/2]

const SCEV * ScalarEvolution::getTripCountFromExitCount	(	const SCEV *	ExitCount,
		Type *	EvalTy,
		const Loop *	L
	)

Convert from an "exit count" (i.e.

"backedge taken count") to a "trip count". A "trip count" is the number of times the header of the loop will execute if an exit is taken after the specified number of backedges have been taken. (e.g. TripCount = ExitCount + 1). Note that the expression can overflow if ExitCount = UINT_MAX. If EvalTy is not wide enough to hold the result without overflow, result unsigned wraps with 2s-complement semantics. ex: EC = 255 (i8), TC = 0 (i8)

Definition at line 8047 of file ScalarEvolution.cpp.

References llvm::ConstantRange::contains(), getAddExpr(), getCouldNotCompute(), llvm::APInt::getMaxValue(), getMinusOne(), getOne(), llvm::Type::getPrimitiveSizeInBits(), getTruncateOrZeroExtend(), llvm::SCEV::getType(), getTypeSizeInBits(), getZeroExtendExpr(), llvm::CmpInst::ICMP_NE, and isLoopEntryGuardedByCond().

◆ getTruncateExpr()

const SCEV * ScalarEvolution::getTruncateExpr	(	const SCEV *	Op,
		Type *	Ty,
		unsigned	Depth = `0`
	)

◆ getTruncateOrNoop()

const SCEV * ScalarEvolution::getTruncateOrNoop	(	const SCEV *	V,
		Type *	Ty
	)

Return a SCEV corresponding to a conversion of the input value to the specified type.

The conversion must not be widening.

Definition at line 4722 of file ScalarEvolution.cpp.

References assert(), getTruncateExpr(), getTypeSizeInBits(), and llvm::Type::isIntOrPtrTy().

Referenced by canBeCheaplyTransformed(), getAnyExtendExpr(), and llvm::SCEVExpander::replaceCongruentIVs().

◆ getTruncateOrSignExtend()

const SCEV * ScalarEvolution::getTruncateOrSignExtend	(	const SCEV *	V,
		Type *	Ty,
		unsigned	Depth = `0`
	)

Return a SCEV corresponding to a conversion of the input value to the specified type.

If the type must be extended, it is sign extended.

Definition at line 4673 of file ScalarEvolution.cpp.

References assert(), llvm::Depth, getSignExtendExpr(), getTruncateExpr(), getTypeSizeInBits(), and llvm::Type::isIntOrPtrTy().

Referenced by findForkedSCEVs(), getGEPExpr(), getSignExtendExprImpl(), and getTruncateExpr().

◆ getTruncateOrZeroExtend()

const SCEV * ScalarEvolution::getTruncateOrZeroExtend	(	const SCEV *	V,
		Type *	Ty,
		unsigned	Depth = `0`
	)

Return a SCEV corresponding to a conversion of the input value to the specified type.

If the type must be extended, it is zero extended.

Definition at line 4661 of file ScalarEvolution.cpp.

References assert(), llvm::Depth, getTruncateExpr(), getTypeSizeInBits(), getZeroExtendExpr(), and llvm::Type::isIntOrPtrTy().

Referenced by BinomialCoefficient(), llvm::AlignmentFromAssumptionsPass::extractAlignmentInfo(), getNewAlignment(), getNumBytes(), getPtrToIntExpr(), getSignExtendExprImpl(), getStartForNegStride(), getTripCountFromExitCount(), getTruncateExpr(), and getZeroExtendExprImpl().

◆ getTypeSizeInBits()

uint64_t ScalarEvolution::getTypeSizeInBits ( Type * Ty ) const

Return the size in bits of the specified type, for which isSCEVable must return true.

Definition at line 4387 of file ScalarEvolution.cpp.

References assert(), getDataLayout(), llvm::DataLayout::getIndexTypeSizeInBits(), llvm::DataLayout::getTypeSizeInBits(), llvm::Type::isPointerTy(), and isSCEVable().

Referenced by llvm::IVUsers::AddUsersIfInteresting(), llvm::SCEVAAResult::alias(), BinomialCoefficient(), computeConstantDifference(), createReplacement(), FindLoopCounter(), llvm::SCEVExpander::generateOverflowCheck(), genLoopLimit(), getAddExpr(), getAnyExtendExpr(), getLosslessPtrToIntExpr(), getMinTrailingZeros(), getMulExpr(), getNoopOrAnyExtend(), getNoopOrSignExtend(), getNoopOrZeroExtend(), llvm::SCEVAddRecExpr::getNumIterationsInRange(), getPowerOfTwo(), getPreStartForExtend(), getSignedOverflowLimitForStep(), getSignExtendExpr(), getSignExtendExprImpl(), getTripCountFromExitCount(), getTruncateExpr(), getTruncateOrNoop(), getTruncateOrSignExtend(), getTruncateOrZeroExtend(), getUDivExpr(), getUMaxFromMismatchedTypes(), getUnsignedOverflowLimitForStep(), getWiderType(), getZeroExtendExpr(), getZeroExtendExprImpl(), isAddRecSExtable(), isAddSExtable(), llvm::HardwareLoopInfo::isHardwareLoopCandidate(), isMulSExtable(), isSimpleCastedPHI(), SolveLinEquationWithOverflow(), SolveQuadraticAddRecRange(), verify(), and visitIVCast().

◆ getUDivCeilSCEV()

const SCEV * ScalarEvolution::getUDivCeilSCEV	(	const SCEV *	N,
		const SCEV *	D
	)

Compute ceil(N / D).

N and D are treated as unsigned values.

Since SCEV doesn't have native ceiling division, this generates a SCEV expression of the following form:

umin(N, 1) + floor((N - umin(N, 1)) / D)

A denominator of zero or poison is handled the same way as getUDivExpr().

Definition at line 12647 of file ScalarEvolution.cpp.

References D, getAddExpr(), getMinusSCEV(), getOne(), getUDivExpr(), getUMinExpr(), and N.

Referenced by getConstantMaxTripCountFromArray().

◆ getUDivExactExpr()

const SCEV * ScalarEvolution::getUDivExactExpr	(	const SCEV *	LHS,
		const SCEV *	RHS
	)

Get a canonical unsigned division expression, or something simpler if possible.

There is no representation for an exact udiv in SCEV IR, but we can attempt to remove factors from the LHS and RHS. We can't do this when it's not exact because the udiv may be clearing bits.

Definition at line 3587 of file ScalarEvolution.cpp.

References llvm::append_range(), llvm::drop_begin(), gcd(), getConstant(), getMulExpr(), getUDivExactExpr(), getUDivExpr(), llvm::APInt::isIntN(), LHS, llvm::Mul, Operands, and RHS.

Referenced by getUDivExactExpr(), and SolveLinEquationWithOverflow().

◆ getUDivExpr()

const SCEV * ScalarEvolution::getUDivExpr	(	const SCEV *	LHS,
		const SCEV *	RHS
	)

Get a canonical unsigned division expression, or something simpler if possible.

Get a canonical UDivExpr for a recurrence. {X,+,N}/C => {Y,+,N}/C where Y=X-(XN). Safe when CN=0.

Definition at line 3415 of file ScalarEvolution.cpp.

References A, assert(), llvm::SCEV::FlagAnyWrap, llvm::SCEV::FlagNW, llvm::IntegerType::get(), getAddExpr(), getAddRecExpr(), llvm::SCEVConstant::getAPInt(), getConstant(), getContext(), getMulExpr(), llvm::Value::getType(), getTypeSizeInBits(), getUDivExpr(), getZeroExtendExpr(), llvm::Type::isPointerTy(), LHS, Operands, registerUser(), RHS, llvm::scUDivExpr, llvm::APInt::umul_ov(), and llvm::APInt::urem().

Referenced by applyLoopGuards(), BinomialCoefficient(), llvm::IndexedReference::computeRefCost(), getAddExpr(), getUDivCeilSCEV(), getUDivExactExpr(), getUDivExpr(), getURemExpr(), getZeroExtendExprImpl(), and llvm::SCEVRewriteVisitor< SC >::visitUDivExpr().

◆ getUMaxExpr() [1/2]

const SCEV * ScalarEvolution::getUMaxExpr	(	const SCEV *	LHS,
		const SCEV *	RHS
	)

Definition at line 4291 of file ScalarEvolution.cpp.

References getUMaxExpr(), LHS, and RHS.

Referenced by applyLoopGuards(), getUMaxExpr(), getUMaxFromMismatchedTypes(), getZeroExtendExprImpl(), llvm::RuntimePointerChecking::insert(), IntersectUnsignedRange(), and llvm::SCEVRewriteVisitor< SC >::visitUMaxExpr().

◆ getUMaxExpr() [2/2]

const SCEV * ScalarEvolution::getUMaxExpr ( SmallVectorImpl< const SCEV * > & Operands )

Definition at line 4296 of file ScalarEvolution.cpp.

References getMinMaxExpr(), and llvm::scUMaxExpr.

◆ getUMaxFromMismatchedTypes()

const SCEV * ScalarEvolution::getUMaxFromMismatchedTypes	(	const SCEV *	LHS,
		const SCEV *	RHS
	)

Promote the operands to the wider of the types using zero-extension, and then perform a umax operation with them.

Definition at line 4733 of file ScalarEvolution.cpp.

References getNoopOrZeroExtend(), llvm::Value::getType(), getTypeSizeInBits(), getUMaxExpr(), getZeroExtendExpr(), LHS, and RHS.

◆ getUMinExpr() [1/2]

const SCEV * ScalarEvolution::getUMinExpr	(	const SCEV *	LHS,
		const SCEV *	RHS,
		bool	Sequential = `false`
	)

Definition at line 4310 of file ScalarEvolution.cpp.

References getUMinExpr(), LHS, and RHS.

Referenced by applyLoopGuards(), createNodeForSelectViaUMinSeq(), getUDivCeilSCEV(), getUMinExpr(), getUMinFromMismatchedTypes(), getZeroExtendExprImpl(), llvm::RuntimePointerChecking::insert(), IntersectUnsignedRange(), llvm::splitLoopBound(), llvm::SCEVRewriteVisitor< SC >::visitSequentialUMinExpr(), and llvm::SCEVRewriteVisitor< SC >::visitUMinExpr().

◆ getUMinExpr() [2/2]

const SCEV * ScalarEvolution::getUMinExpr	(	SmallVectorImpl< const SCEV * > &	Operands,
		bool	Sequential = `false`
	)

Definition at line 4316 of file ScalarEvolution.cpp.

References getMinMaxExpr(), getSequentialMinMaxExpr(), llvm::scSequentialUMinExpr, and llvm::scUMinExpr.

◆ getUMinFromMismatchedTypes() [1/2]

const SCEV * ScalarEvolution::getUMinFromMismatchedTypes	(	const SCEV *	LHS,
		const SCEV *	RHS,
		bool	Sequential = `false`
	)

Promote the operands to the wider of the types using zero-extension, and then perform a umin operation with them.

Definition at line 4746 of file ScalarEvolution.cpp.

References getUMinFromMismatchedTypes(), LHS, and RHS.

Referenced by createReplacement(), getConstantMaxTripCountFromArray(), getMinAnalyzeableBackedgeTakenCount(), and getUMinFromMismatchedTypes().

◆ getUMinFromMismatchedTypes() [2/2]

const SCEV * ScalarEvolution::getUMinFromMismatchedTypes	(	SmallVectorImpl< const SCEV * > &	Ops,
		bool	Sequential = `false`
	)

Promote the operands to the wider of the types using zero-extension, and then perform a umin operation with them.

N-ary function.

Definition at line 4754 of file ScalarEvolution.cpp.

References assert(), llvm::SmallVectorBase< Size_T >::empty(), getNoopOrZeroExtend(), llvm::SCEV::getType(), getUMinExpr(), getWiderType(), llvm::SmallVectorTemplateBase< T, bool >::push_back(), and llvm::SmallVectorBase< Size_T >::size().

◆ getUnknown()

const SCEV * ScalarEvolution::getUnknown ( Value * V )

Definition at line 4350 of file ScalarEvolution.cpp.

References assert(), SCEVUnknown, and llvm::scUnknown.

Referenced by llvm::InductionDescriptor::isFPInductionPHI(), and verify().

◆ getUnsignedRange()

ConstantRange llvm::ScalarEvolution::getUnsignedRange ( const SCEV * S )

inline

Determine the unsigned range for a particular SCEV.

NOTE: This returns a copy of the reference returned by getRangeRef.

Definition at line 978 of file ScalarEvolution.h.

Referenced by llvm::SCEVAAResult::alias(), getBoundsCheckCond(), getZeroExtendExprImpl(), mustBeFiniteCountedLoop(), print(), and StrengthenNoWrapFlags().

◆ getUnsignedRangeMax()

APInt llvm::ScalarEvolution::getUnsignedRangeMax ( const SCEV * S )

inline

Determine the max of the unsigned range for a particular SCEV.

Definition at line 988 of file ScalarEvolution.h.

References llvm::ConstantRange::getUnsignedMax().

Referenced by getUnsignedOverflowLimitForStep(), llvm::ARMTTIImpl::isHardwareLoopProfitable(), and SimplifyICmpOperands().

◆ getUnsignedRangeMin()

APInt llvm::ScalarEvolution::getUnsignedRangeMin ( const SCEV * S )

inline

Determine the min of the unsigned range for a particular SCEV.

Definition at line 983 of file ScalarEvolution.h.

References llvm::ConstantRange::getUnsignedMin().

Referenced by isKnownNonZero(), and SimplifyICmpOperands().

◆ getURemExpr()

const SCEV * ScalarEvolution::getURemExpr	(	const SCEV *	LHS,
		const SCEV *	RHS
	)

Represents an unsigned remainder expression based on unsigned division.

Definition at line 3386 of file ScalarEvolution.cpp.

References assert(), llvm::SCEV::FlagNUW, llvm::IntegerType::get(), getContext(), getEffectiveSCEVType(), getMinusSCEV(), getMulExpr(), getTruncateExpr(), llvm::Value::getType(), getUDivExpr(), getZero(), getZeroExtendExpr(), LHS, and RHS.

Referenced by applyLoopGuards(), llvm::LoopVectorizationCostModel::computeMaxVF(), getNewAlignmentDiff(), and getZeroExtendExprImpl().

◆ getVScale()

const SCEV * ScalarEvolution::getVScale ( Type * Ty )

Definition at line 499 of file ScalarEvolution.cpp.

References llvm::scVScale.

Referenced by getSizeOfExpr().

◆ getWiderType()

Type * ScalarEvolution::getWiderType	(	Type *	Ty1,
		Type *	Ty2
	)		const

Definition at line 4408 of file ScalarEvolution.cpp.

References getTypeSizeInBits(), and T1.

Referenced by llvm::IndexedReference::computeRefCost(), getUMinFromMismatchedTypes(), and optimizeLoopExitWithUnknownExitCount().

◆ getWrapPredicate()

const SCEVPredicate * ScalarEvolution::getWrapPredicate	(	const SCEVAddRecExpr *	AR,
		SCEVWrapPredicate::IncrementWrapFlags	AddedFlags
	)

Definition at line 14418 of file ScalarEvolution.cpp.

References llvm::SCEVPredicate::P_Wrap.

Referenced by llvm::PredicatedScalarEvolution::setNoOverflow().

◆ getZero()

const SCEV * llvm::ScalarEvolution::getZero ( Type * Ty )

inline

Return a SCEV for the constant 0 of a specific type.

Definition at line 654 of file ScalarEvolution.h.

References getConstant().

Referenced by detectShiftUntilZeroIdiom(), llvm::AlignmentFromAssumptionsPass::extractAlignmentInfo(), getAddExpr(), getLosslessPtrToIntExpr(), getMinusSCEV(), getMulExpr(), llvm::SCEVAddRecExpr::getNumIterationsInRange(), getSequentialMinMaxExpr(), getTruncateExpr(), getURemExpr(), llvm::isKnownNegativeInLoop(), llvm::isKnownNonNegativeInLoop(), llvm::isKnownNonPositiveInLoop(), llvm::isKnownPositiveInLoop(), isLoopBackedgeGuardedByCond(), and removePointerBase().

◆ getZeroExtendExpr()

const SCEV * ScalarEvolution::getZeroExtendExpr	(	const SCEV *	Op,
		Type *	Ty,
		unsigned	Depth = `0`
	)

◆ getZeroExtendExprImpl()

const SCEV * ScalarEvolution::getZeroExtendExprImpl	(	const SCEV *	Op,
		Type *	Ty,
		unsigned	Depth = `0`
	)

Definition at line 1567 of file ScalarEvolution.cpp.

References assert(), llvm::AssumptionCache::assumptions(), llvm::BitWidth, llvm::CallingConv::C, llvm::ConstantRange::contains(), D, llvm::Depth, extractConstantWithoutWrapping(), llvm::SCEV::FlagAnyWrap, llvm::SCEV::FlagNSW, llvm::SCEV::FlagNUW, llvm::SCEV::FlagNW, llvm::IntegerType::get(), getAddExpr(), getAddRecExpr(), getConstant(), getConstantMaxBackedgeTakenCount(), getContext(), llvm::APInt::getMaxValue(), getMulExpr(), getSignedRangeMin(), getSignExtendExpr(), getTruncateExpr(), getTruncateOrZeroExtend(), llvm::SCEV::getType(), getTypeSizeInBits(), getUDivExpr(), getUMaxExpr(), getUMinExpr(), getUnsignedRange(), getURemExpr(), getZeroExtendExpr(), llvm::ConstantExpr::getZExt(), llvm::CmpInst::ICMP_UGT, isKnownNegative(), isKnownOnEveryIteration(), isLoopBackedgeGuardedByCond(), isSCEVable(), LHS, MaxCastDepth, N, Operands, llvm::SmallVectorTemplateBase< T, bool >::push_back(), registerUser(), RHS, llvm::scZeroExtend, setNoWrapFlags(), llvm::ConstantRange::truncate(), X, llvm::ConstantRange::zeroExtend(), and llvm::ConstantRange::zextOrTrunc().

Referenced by getZeroExtendExpr().

◆ hasComputableLoopEvolution()

bool ScalarEvolution::hasComputableLoopEvolution	(	const SCEV *	S,
		const Loop *	L
	)

Return true if the given SCEV changes value in a known way in the specified loop.

This property being true implies that the value is variant in the loop AND that we can emit an expression to compute the value of the expression at any particular loop iteration.

Definition at line 13767 of file ScalarEvolution.cpp.

References getLoopDisposition(), and LoopComputable.

◆ hasFlags()

static bool llvm::ScalarEvolution::hasFlags	(	SCEV::NoWrapFlags	Flags,
		SCEV::NoWrapFlags	TestFlags
	)

inlinestatic

Definition at line 484 of file ScalarEvolution.h.

References Flags, and maskFlags().

Referenced by getAddExpr(), getMinusSCEV(), getMulExpr(), and StrengthenNoWrapFlags().

◆ hasLoopInvariantBackedgeTakenCount()

bool ScalarEvolution::hasLoopInvariantBackedgeTakenCount ( const Loop * L )

Return true if the specified loop has an analyzable loop-invariant backedge-taken count.

Definition at line 13481 of file ScalarEvolution.cpp.

References getBackedgeTakenCount().

Referenced by canFoldTermCondOfLoop(), llvm::ARMTTIImpl::isHardwareLoopProfitable(), llvm::IVUsers::print(), and PrintLoopInfo().

◆ hasOperand()

bool ScalarEvolution::hasOperand	(	const SCEV *	S,
		const SCEV *	Op
	)		const

Test whether the given SCEV has Op as a direct or indirect operand.

Definition at line 13854 of file ScalarEvolution.cpp.

References llvm::SCEVExprContains().

◆ instructionCouldExistWitthOperands()

bool ScalarEvolution::instructionCouldExistWitthOperands	(	const SCEV *	A,
		const SCEV *	B
	)

Return true if there exists a point in the program at which both A and B could be operands to the same instruction.

SCEV expressions are generally assumed to correspond to instructions which could exists in IR. In general, this requires that there exists a use point in the program where all operands dominate the use.

Example: loop { if loop { v1 = load @global1; } else loop { v2 = load @global2; } } No SCEV with operand V1, and v2 can exist in this program.

For a valid use point to exist, the defining scope of one operand must dominate the other.

Definition at line 4412 of file ScalarEvolution.cpp.

References A, B, and llvm::DominatorTree::dominates().

Referenced by canComputePointerDiff().

◆ invalidate()

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

Definition at line 14308 of file ScalarEvolution.cpp.

References F, llvm::PreservedAnalyses::getChecker(), and llvm::AnalysisManager< IRUnitT, ExtraArgTs >::Invalidator::invalidate().

◆ isAvailableAtLoopEntry()

bool ScalarEvolution::isAvailableAtLoopEntry	(	const SCEV *	S,
		const Loop *	L
	)

Determine if the SCEV can be evaluated at loop's entry.

It is true if it doesn't depend on a SCEVUnknown of an instruction which is dominated by the header of loop L.

Definition at line 2509 of file ScalarEvolution.cpp.

References isLoopInvariant(), and properlyDominates().

Referenced by llvm::cannotBeMaxInLoop(), llvm::cannotBeMinInLoop(), getAddExpr(), getMulExpr(), llvm::hasProcessableCondition(), llvm::isKnownNegativeInLoop(), llvm::isKnownNonNegativeInLoop(), llvm::isKnownNonPositiveInLoop(), llvm::isKnownPositiveInLoop(), isKnownViaInduction(), isLoopEntryGuardedByCond(), isSafeDecreasingBound(), and isSafeIncreasingBound().

◆ isBackedgeTakenCountMaxOrZero()

bool ScalarEvolution::isBackedgeTakenCountMaxOrZero ( const Loop * L )

Return true if the backedge taken count is either the value returned by getConstantMaxBackedgeTakenCount or zero.

Definition at line 8318 of file ScalarEvolution.cpp.

Referenced by PrintLoopInfo(), tryToUnrollLoop(), and llvm::UnrollLoop().

◆ isBasicBlockEntryGuardedByCond()

bool ScalarEvolution::isBasicBlockEntryGuardedByCond	(	const BasicBlock *	BB,
		ICmpInst::Predicate	Pred,
		const SCEV *	LHS,
		const SCEV *	RHS
	)

Test whether entry to the basic block is protected by a conditional between LHS and RHS.

Definition at line 11443 of file ScalarEvolution.cpp.

References assert(), llvm::AssumptionCache::assumptions(), llvm::dbgs(), llvm::DominatorTree::dominates(), llvm::BasicBlock::front(), llvm::BranchInst::getCondition(), llvm::Module::getFunction(), llvm::LoopBase< BlockT, LoopT >::getHeader(), llvm::LoopInfoBase< BlockT, LoopT >::getLoopFor(), llvm::LoopBase< BlockT, LoopT >::getLoopPredecessor(), llvm::Intrinsic::getName(), llvm::CmpInst::getNonStrictPredicate(), llvm::GlobalValue::getParent(), llvm::BasicBlock::getParent(), llvm::BasicBlock::getSinglePredecessor(), llvm::BranchInst::getSuccessor(), llvm::CmpInst::ICMP_NE, llvm::DominatorTree::isReachableFromEntry(), llvm::BranchInst::isUnconditional(), LHS, P, RHS, llvm::verifyFunction(), and VerifyIR.

Referenced by evaluatePredicateAt(), isKnownPredicateAt(), and isLoopEntryGuardedByCond().

◆ isKnownNegative()

bool ScalarEvolution::isKnownNegative ( const SCEV * S )

Test if the given expression is known to be negative.

Definition at line 10787 of file ScalarEvolution.cpp.

References getSignedRangeMax(), and llvm::APInt::isNegative().

Referenced by llvm::SCEVExpander::generateOverflowCheck(), getSignedOverflowLimitForStep(), getZeroExtendExprImpl(), isOneDimensionalArray(), and isSafeDecreasingBound().

◆ isKnownNonNegative()

bool ScalarEvolution::isKnownNonNegative ( const SCEV * S )

Test if the given expression is known to be non-negative.

Definition at line 10795 of file ScalarEvolution.cpp.

References getSignedRangeMin(), and llvm::APInt::isNegative().

Referenced by applyLoopGuards(), detectShiftUntilZeroIdiom(), getGEPExpr(), getLoopInvariantPredicate(), getMinusSCEV(), getSignExtendExprImpl(), and StrengthenNoWrapFlags().

◆ isKnownNonPositive()

bool ScalarEvolution::isKnownNonPositive ( const SCEV * S )

Test if the given expression is known to be non-positive.

Definition at line 10799 of file ScalarEvolution.cpp.

References getSignedRangeMax(), and llvm::APInt::isStrictlyPositive().

◆ isKnownNonZero()

bool ScalarEvolution::isKnownNonZero ( const SCEV * S )

Test if the given expression is known to be non-zero.

Definition at line 10803 of file ScalarEvolution.cpp.

References getUnsignedRangeMin().

Referenced by breakBackedgeIfNotTaken().

◆ isKnownOnEveryIteration()

bool ScalarEvolution::isKnownOnEveryIteration	(	ICmpInst::Predicate	Pred,
		const SCEVAddRecExpr *	LHS,
		const SCEV *	RHS
	)

Test if the condition described by Pred, LHS, RHS is known to be true on every iteration of the loop of the recurrency LHS.

Definition at line 10919 of file ScalarEvolution.cpp.

References isLoopBackedgeGuardedByCond(), isLoopEntryGuardedByCond(), LHS, and RHS.

Referenced by getZeroExtendExprImpl().

◆ isKnownPositive()

bool ScalarEvolution::isKnownPositive ( const SCEV * S )

Test if the given expression is known to be positive.

Definition at line 10791 of file ScalarEvolution.cpp.

References getSignedRangeMin(), and llvm::APInt::isStrictlyPositive().

Referenced by llvm::SCEVExpander::generateOverflowCheck(), getLoopInvariantPredicate(), getPreStartForExtend(), getSignedOverflowLimitForStep(), and isSafeDependenceDistance().

◆ isKnownPredicate()

bool ScalarEvolution::isKnownPredicate	(	ICmpInst::Predicate	Pred,
		const SCEV *	LHS,
		const SCEV *	RHS
	)

Test if the given expression is known to satisfy the condition described by Pred, LHS, and RHS.

Definition at line 10870 of file ScalarEvolution.cpp.

References isKnownViaInduction(), LHS, RHS, and SimplifyICmpOperands().

Referenced by llvm::calculateUpperBound(), countToEliminateCompares(), evaluatePredicate(), isKnownPredicateAt(), IsKnownPredicateViaAddRecStart(), normalizePredicate(), and llvm::VPlanTransforms::optimizeForVFAndUF().

◆ isKnownPredicateAt()

bool ScalarEvolution::isKnownPredicateAt	(	ICmpInst::Predicate	Pred,
		const SCEV *	LHS,
		const SCEV *	RHS,
		const Instruction *	CtxI
	)

Test if the given expression is known to satisfy the condition described by Pred, LHS, and RHS in the given Context.

Definition at line 10895 of file ScalarEvolution.cpp.

References llvm::Instruction::getParent(), isBasicBlockEntryGuardedByCond(), isKnownPredicate(), LHS, and RHS.

Referenced by canOverlap(), createReplacement(), getLoopInvariantExitCondDuringFirstIterationsImpl(), getLoopInvariantPredicate(), and willNotOverflow().

◆ isKnownViaInduction()

bool ScalarEvolution::isKnownViaInduction	(	ICmpInst::Predicate	Pred,
		const SCEV *	LHS,
		const SCEV *	RHS
	)

We'd like to check the predicate on every iteration of the most dominated loop between loops used in LHS and RHS.

To do this we use the following list of steps:

Collect set S all loops on which either LHS or RHS depend.
If S is non-empty a. Let PD be the element of S which is dominated by all other elements. b. Let E(LHS) be value of LHS on entry of PD. To get E(LHS), we should just take LHS and replace all AddRecs that are attached to PD on with their entry values. Define E(RHS) in the same way. c. Let B(LHS) be value of L on backedge of PD. To get B(LHS), we should just take LHS and replace all AddRecs that are attached to PD on with their backedge values. Define B(RHS) in the same way. d. Note that E(LHS) and E(RHS) are automatically available on entry of PD, so we can assert on that. e. Return true if isLoopEntryGuardedByCond(Pred, E(LHS), E(RHS)) && isLoopBackedgeGuardedByCond(Pred, B(LHS), B(RHS))

Definition at line 10819 of file ScalarEvolution.cpp.

References assert(), llvm::SmallPtrSetImpl< PtrType >::begin(), llvm::DominatorTree::dominates(), llvm::SmallPtrSetImplBase::empty(), llvm::SmallPtrSetImpl< PtrType >::end(), getCouldNotCompute(), isAvailableAtLoopEntry(), isLoopBackedgeGuardedByCond(), isLoopEntryGuardedByCond(), LHS, RHS, and SplitIntoInitAndPostInc().

Referenced by isKnownPredicate().

◆ isLoopBackedgeGuardedByCond()

bool ScalarEvolution::isLoopBackedgeGuardedByCond	(	const Loop *	L,
		ICmpInst::Predicate	Pred,
		const SCEV *	LHS,
		const SCEV *	RHS
	)

Test whether the backedge of the loop is protected by a conditional between LHS and RHS.

isLoopBackedgeGuardedByCond - Test whether the backedge of the loop is protected by a conditional between LHS and RHS.

This is used to eliminate casts.

This is used to to eliminate casts.

Definition at line 11338 of file ScalarEvolution.cpp.

References assert(), llvm::AssumptionCache::assumptions(), llvm::dbgs(), llvm::DominatorTree::dominates(), llvm::SCEV::FlagNUW, llvm::SCEV::FlagNW, getAddRecExpr(), llvm::BranchInst::getCondition(), getCouldNotCompute(), getOne(), llvm::BasicBlock::getSinglePredecessor(), llvm::BranchInst::getSuccessor(), llvm::BasicBlock::getTerminator(), llvm::SCEV::getType(), getZero(), llvm::CmpInst::ICMP_ULT, llvm::BranchInst::isConditional(), llvm::DominatorTree::isReachableFromEntry(), llvm::BasicBlockEdge::isSingleEdge(), LHS, RHS, llvm::verifyFunction(), and VerifyIR.

Referenced by getLoopInvariantExitCondDuringFirstIterationsImpl(), getLoopInvariantPredicate(), getZeroExtendExprImpl(), isKnownOnEveryIteration(), and isKnownViaInduction().

◆ isLoopEntryGuardedByCond()

bool ScalarEvolution::isLoopEntryGuardedByCond	(	const Loop *	L,
		ICmpInst::Predicate	Pred,
		const SCEV *	LHS,
		const SCEV *	RHS
	)

Test whether entry to the loop is protected by a conditional between LHS and RHS.

This is used to help avoid max expressions in loop trip counts, and to eliminate casts.

Definition at line 11543 of file ScalarEvolution.cpp.

References assert(), isAvailableAtLoopEntry(), isBasicBlockEntryGuardedByCond(), LHS, and RHS.

Referenced by llvm::cannotBeMaxInLoop(), llvm::cannotBeMinInLoop(), llvm::findSplitCandidate(), getPreStartForExtend(), getTripCountFromExitCount(), llvm::isKnownNegativeInLoop(), llvm::isKnownNonNegativeInLoop(), llvm::isKnownNonPositiveInLoop(), isKnownOnEveryIteration(), llvm::isKnownPositiveInLoop(), isKnownViaInduction(), isSafeDecreasingBound(), and isSafeIncreasingBound().

◆ isLoopInvariant()

bool ScalarEvolution::isLoopInvariant	(	const SCEV *	S,
		const Loop *	L
	)

Return true if the value of the given SCEV is unchanging in the specified loop.

Definition at line 13763 of file ScalarEvolution.cpp.

References getLoopDisposition(), and LoopInvariant.

Referenced by llvm::RecurrenceDescriptor::AddReductionVar(), canTailPredicateLoop(), computeUnrollAndJamCount(), createWidenInductionRecipes(), findForkedPointer(), genLoopLimit(), getAddRecExpr(), getAddressAccessSCEV(), getConstantMaxTripCountFromArray(), getLoopInvariantExitCondDuringFirstIterationsImpl(), getLoopInvariantPredicate(), getStrideFromPointer(), hasComputableBounds(), llvm::RuntimePointerChecking::insert(), llvm::Loop::isAuxiliaryInductionVariable(), isAvailableAtLoopEntry(), llvm::isDereferenceableAndAlignedInLoop(), llvm::HardwareLoopInfo::isHardwareLoopCandidate(), llvm::InductionDescriptor::isInductionPHI(), llvm::LoopAccessInfo::isInvariant(), isNoWrap(), isOneDimensionalArray(), mayUsePostIncMode(), print(), llvm::rewriteLoopExitValues(), SimplifyICmpOperands(), and stripGetElementPtr().

◆ isSCEVable()

bool ScalarEvolution::isSCEVable ( Type * Ty ) const

Test if values of the given type are analyzable within the SCEV framework.

This primarily includes integer types, and it can optionally include pointer types if the ScalarEvolution class has access to target-specific information.

Definition at line 4380 of file ScalarEvolution.cpp.

References llvm::Type::isIntOrPtrTy().

Referenced by llvm::IVUsers::AddUsersIfInteresting(), canFoldTermCondOfLoop(), DbgGatherSalvagableDVI(), findForkedPointer(), findIVOperand(), forgetBlockAndLoopDispositions(), getAnyExtendExpr(), getEffectiveSCEVType(), GetInductionVariable(), getSCEV(), getSignExtendExpr(), getSignExtendExprImpl(), getTruncateExpr(), getTypeSizeInBits(), getZeroExtendExpr(), getZeroExtendExprImpl(), isExistingPhi(), isHighCostExpansion(), llvm::LoopAccessInfo::isInvariant(), isLoopCounter(), llvm::isProcessableCondBI(), isSimpleIVUser(), llvm::LoopVectorizationLegality::isUniform(), print(), llvm::PredicatedScalarEvolution::print(), llvm::SCEVExpander::replaceCongruentIVs(), llvm::rewriteLoopExitValues(), and llvm::splitLoopBound().

◆ loopHasNoAbnormalExits()

bool llvm::ScalarEvolution::loopHasNoAbnormalExits ( const Loop * L )

inline

Return true if the loop has no abnormal exits.

That is, if the loop is not infinite, it must exit through an explicit edge in the CFG. (As opposed to either a) throwing out of the function or b) entering a well defined infinite loop in some callee.)

Definition at line 1303 of file ScalarEvolution.h.

Referenced by llvm::UnrollRuntimeLoopRemainder().

◆ loopIsFiniteByAssumption()

bool ScalarEvolution::loopIsFiniteByAssumption ( const Loop * L )

Return true if this loop is finite by assumption.

That is, to be infinite, it must also be undefined.

Definition at line 7353 of file ScalarEvolution.cpp.

References llvm::isFinite(), and llvm::isMustProgress().

◆ maskFlags()

static SCEV::NoWrapFlags llvm::ScalarEvolution::maskFlags	(	SCEV::NoWrapFlags	Flags,
		int	Mask
	)

inlinestatic

Convenient NoWrapFlags manipulation that hides enum casts and is visible in the ScalarEvolution name space.

Definition at line 472 of file ScalarEvolution.h.

References Flags.

Referenced by getAddExpr(), getAddRecExpr(), getMulExpr(), getPreStartForExtend(), hasFlags(), llvm::SCEVExpander::hoistIVInc(), and StrengthenNoWrapFlags().

◆ print()

void ScalarEvolution::print ( raw_ostream & OS ) const

Definition at line 13582 of file ScalarEvolution.cpp.

References ClassifyExpressions, llvm::depth_first(), getLoopDisposition(), llvm::LoopInfoBase< BlockT, LoopT >::getLoopFor(), getSCEV(), getSCEVAtScope(), getSignedRange(), getUnsignedRange(), I, instructions, isLoopInvariant(), isSCEVable(), loopDispositionToStr(), OS, llvm::SCEV::print(), llvm::ConstantRange::print(), llvm::Value::printAsOperand(), and PrintLoopInfo().

Referenced by llvm::ScalarEvolutionWrapperPass::print().

◆ properlyDominates()

bool ScalarEvolution::properlyDominates	(	const SCEV *	S,
		const BasicBlock *	BB
	)

Return true if elements that makes up the given SCEV properly dominate the specified basic block.

Definition at line 13850 of file ScalarEvolution.cpp.

References getBlockDisposition(), and ProperlyDominatesBlock.

Referenced by DoInitialMatch(), isAvailableAtLoopEntry(), llvm::SCEVExpander::isSafeToExpandAt(), and SimplifyICmpOperands().

◆ registerUser()

void ScalarEvolution::registerUser	(	const SCEV *	User,
		ArrayRef< const SCEV * >	Ops
	)

Notify this ScalarEvolution that User directly uses SCEVs in Ops.

Definition at line 14714 of file ScalarEvolution.cpp.

Referenced by getLosslessPtrToIntExpr(), getMinMaxExpr(), getSequentialMinMaxExpr(), getSignExtendExprImpl(), getTruncateExpr(), getUDivExpr(), and getZeroExtendExprImpl().

◆ removePointerBase()

const SCEV * ScalarEvolution::removePointerBase ( const SCEV * S )

Compute an expression equivalent to S - getPointerBase(S).

Definition at line 4581 of file ScalarEvolution.cpp.

References llvm::Add, assert(), llvm::SCEV::FlagAnyWrap, getAddExpr(), getAddRecExpr(), getZero(), P, and removePointerBase().

Referenced by getMinusSCEV(), and removePointerBase().

◆ rewriteUsingPredicate()

const SCEV * ScalarEvolution::rewriteUsingPredicate	(	const SCEV *	S,
		const Loop *	L,
		const SCEVPredicate &	A
	)

Re-writes the SCEV according to the Predicates in A.

Definition at line 14559 of file ScalarEvolution.cpp.

Referenced by llvm::PredicatedScalarEvolution::getSCEV().

◆ setFlags()

static SCEV::NoWrapFlags llvm::ScalarEvolution::setFlags	(	SCEV::NoWrapFlags	Flags,
		SCEV::NoWrapFlags	OnFlags
	)

inlinestatic

Definition at line 476 of file ScalarEvolution.h.

References Flags.

Referenced by getAddExpr(), llvm::SCEVWrapPredicate::getImpliedFlags(), getMulExpr(), getStrengthenedNoWrapFlagsFromBinOp(), llvm::SCEVWrapPredicate::isAlwaysTrue(), llvm::SCEVAddRecExpr::setNoWrapFlags(), and StrengthenNoWrapFlags().

◆ setNoWrapFlags()

void ScalarEvolution::setNoWrapFlags	(	SCEVAddRecExpr *	AddRec,
		SCEV::NoWrapFlags	Flags
	)

Update no-wrap flags of an AddRec.

This may drop the cached info about this AddRec (such as range info) in case if new flags may potentially sharpen it.

Definition at line 6334 of file ScalarEvolution.cpp.

References Flags, llvm::SCEVNAryExpr::getNoWrapFlags(), and llvm::SCEVAddRecExpr::setNoWrapFlags().

Referenced by getPreStartForExtend(), getSignExtendExprImpl(), and getZeroExtendExprImpl().

◆ SimplifyICmpOperands()

bool ScalarEvolution::SimplifyICmpOperands	(	ICmpInst::Predicate &	Pred,
		const SCEV *&	LHS,
		const SCEV *&	RHS,
		unsigned	Depth = `0`
	)

Simplify LHS and RHS in a comparison with predicate Pred.

Return true iff any changes were made. If the operands are provably equal or unequal, LHS and RHS are set to the same value and Pred is set to either ICMP_EQ or ICMP_NE.

Definition at line 10591 of file ScalarEvolution.cpp.

Referenced by isKnownPredicate(), and SimplifyICmpOperands().

◆ SplitIntoInitAndPostInc()

std::pair< const SCEV , const SCEV > ScalarEvolution::SplitIntoInitAndPostInc	(	const Loop *	L,
		const SCEV *	S
	)

Splits SCEV expression S into two SCEVs.

One of them is obtained from S by substitution of all AddRec sub-expression related to loop L with initial value of that SCEV. The second is obtained from S by substitution of all AddRec sub-expressions related to loop L with post increment of this AddRec in the loop L. In both cases all other AddRec sub-expressions (not related to L) remain the same. If the S contains non-invariant unknown SCEV the function returns CouldNotCompute SCEV in both values of std::pair. For example, for SCEV S={0, +, 1}<L1> + {0, +, 1}<L2> and loop L=L1 the function returns pair: first = {0, +, 1}<L2> second = {1, +, 1}<L1> + {0, +, 1}<L2> We can see that for the first AddRec sub-expression it was replaced with 0 (initial value) for the first element and to {1, +, 1}<L1> (post increment value) for the second one. In both cases AddRec expression related to L2 remains the same.

Definition at line 10808 of file ScalarEvolution.cpp.

References assert(), getCouldNotCompute(), and PostInc.

Referenced by isKnownViaInduction().

◆ verify()

void ScalarEvolution::verify ( ) const

Definition at line 14015 of file ScalarEvolution.cpp.

References llvm::SmallVectorImpl< T >::append(), llvm::append_range(), assert(), llvm::LoopInfoBase< BlockT, LoopT >::begin(), llvm::SmallPtrSetImpl< PtrType >::contains(), containsUndefs(), llvm::dbgs(), llvm::SmallVectorBase< Size_T >::empty(), llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::end(), llvm::LoopInfoBase< BlockT, LoopT >::end(), F, llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::find(), getBackedgeTakenCount(), getBlockDisposition(), getConstant(), getConstantMultiple(), getCouldNotCompute(), llvm::SCEVAddRecExpr::getLoop(), getLoopDisposition(), getMinusSCEV(), llvm::Value::getName(), getSCEV(), getTypeSizeInBits(), getUnknown(), llvm::SCEVUnknown::getValue(), getZeroExtendExpr(), I, llvm::SmallPtrSetImpl< PtrType >::insert(), llvm::is_contained(), llvm::SCEV::isZero(), loopDispositionToStr(), llvm::SCEV::operands(), llvm::SmallVectorImpl< T >::pop_back_val(), llvm::APInt::urem(), and VerifySCEVStrict.

Referenced by llvm::FunctionToLoopPassAdaptor::run(), llvm::LoopVectorizePass::run(), llvm::UnrollAndJamLoop(), and llvm::ScalarEvolutionWrapperPass::verifyAnalysis().

◆ willNotOverflow()

bool ScalarEvolution::willNotOverflow	(	Instruction::BinaryOps	BinOp,
		bool	Signed,
		const SCEV *	LHS,
		const SCEV *	RHS,
		const Instruction *	CtxI = `nullptr`
	)

Is operation BinOp between LHS and RHS provably does not have a signed/unsigned overflow (Signed)? If CtxI is specified, the no-overflow fact should be true in the context of this instruction.

Definition at line 2302 of file ScalarEvolution.cpp.

References A, B, llvm::CallingConv::C, llvm::SCEV::FlagAnyWrap, llvm::IntegerType::get(), getAddExpr(), getConstant(), llvm::APInt::getMaxValue(), getMinusSCEV(), llvm::APInt::getMinValue(), getMulExpr(), llvm::APInt::getSignedMaxValue(), llvm::APInt::getSignedMinValue(), getSignExtendExpr(), llvm::Value::getType(), getZeroExtendExpr(), llvm::CmpInst::ICMP_SLE, llvm::CmpInst::ICMP_ULE, isKnownPredicateAt(), LHS, llvm_unreachable, Operation, RHS, and Signed.

Referenced by getStrengthenedNoWrapFlagsFromBinOp().

Friends And Related Function Documentation

◆ ScalarEvolutionsTest

friend class ScalarEvolutionsTest

friend

Definition at line 453 of file ScalarEvolution.h.

◆ SCEVCallbackVH

friend class SCEVCallbackVH

friend

Definition at line 1370 of file ScalarEvolution.h.

◆ SCEVExpander

friend class SCEVExpander

friend

Definition at line 1371 of file ScalarEvolution.h.

◆ SCEVUnknown

friend class SCEVUnknown

friend

Definition at line 1372 of file ScalarEvolution.h.

Referenced by getUnknown().

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

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

Classes

Public Types

Public Member Functions

Static Public Member Functions

Friends

Detailed Description

Member Enumeration Documentation

◆ BlockDisposition

◆ ExitCountKind

◆ LoopDisposition

◆ MonotonicPredicateType

Constructor & Destructor Documentation

◆ ScalarEvolution() [1/2]

◆ ScalarEvolution() [2/2]

◆ ~ScalarEvolution()

Member Function Documentation

◆ applyLoopGuards()

◆ clearFlags()

◆ computeConstantDifference()

◆ computeExitLimitFromCond()

◆ containsAddRecurrence()

◆ containsErasedValue()

◆ containsUndefs()

◆ convertSCEVToAddRecWithPredicates()

◆ createAddRecFromPHIWithCasts()

◆ dominates()

◆ evaluatePredicate()

◆ evaluatePredicateAt()

◆ forgetAllLoops()

◆ forgetBlockAndLoopDispositions()

◆ forgetLoop()

◆ forgetLoopDispositions()

◆ forgetTopmostLoop()

◆ forgetValue()

◆ getAbsExpr()

◆ getAddExpr() [1/3]

◆ getAddExpr() [2/3]

◆ getAddExpr() [3/3]

◆ getAddRecExpr() [1/3]

◆ getAddRecExpr() [2/3]

◆ getAddRecExpr() [3/3]

◆ getAnyExtendExpr()

◆ getBackedgeTakenCount()

◆ getBlockDisposition()

◆ getCastExpr()

◆ getComparePredicate()

◆ getConstant() [1/3]

◆ getConstant() [2/3]

◆ getConstant() [3/3]

◆ getConstantMaxBackedgeTakenCount()

◆ getConstantMaxTripCountFromArray()

◆ getConstantMultiple()

◆ getContext()

◆ getCouldNotCompute()

◆ getDataLayout()

◆ getEffectiveSCEVType()

◆ getElementSize()

◆ getEqualPredicate()

◆ getExitCount()

◆ getGEPExpr()

◆ getLoopDisposition()

◆ getLoopInvariantExitCondDuringFirstIterations()

◆ getLoopInvariantExitCondDuringFirstIterationsImpl()

◆ getLoopInvariantPredicate()

◆ getLosslessPtrToIntExpr()

◆ getMinMaxExpr()

◆ getMinTrailingZeros()

◆ getMinusOne()

◆ getMinusSCEV()

◆ getMonotonicPredicateType()

◆ getMulExpr() [1/3]

◆ getMulExpr() [2/3]

◆ getMulExpr() [3/3]

◆ getNegativeSCEV()

◆ getNonZeroConstantMultiple()

◆ getNoopOrAnyExtend()

◆ getNoopOrSignExtend()

◆ getNoopOrZeroExtend()

◆ getNotSCEV()

◆ getOffsetOfExpr()