LLVM 19.0.0git
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llvm::ScalarEvolution Class Reference

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 ()
 
LLVMContextgetContext () 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.
 
TypegetEffectiveSCEVType (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.
 
TypegetWiderType (Type *Ty1, Type *Ty2) const
 
bool instructionCouldExistWithOperands (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::NoWrapFlagsgetStrengthenedNoWrapFlagsFromBinOp (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 SCEVgetSCEV (Value *V)
 Return a SCEV expression for the full generality of the specified expression.
 
const SCEVgetExistingSCEV (Value *V)
 Return an existing SCEV for V if there is one, otherwise return nullptr.
 
const SCEVgetConstant (ConstantInt *V)
 
const SCEVgetConstant (const APInt &Val)
 
const SCEVgetConstant (Type *Ty, uint64_t V, bool isSigned=false)
 
const SCEVgetLosslessPtrToIntExpr (const SCEV *Op, unsigned Depth=0)
 
const SCEVgetPtrToIntExpr (const SCEV *Op, Type *Ty)
 
const SCEVgetTruncateExpr (const SCEV *Op, Type *Ty, unsigned Depth=0)
 
const SCEVgetVScale (Type *Ty)
 
const SCEVgetElementCount (Type *Ty, ElementCount EC)
 
const SCEVgetZeroExtendExpr (const SCEV *Op, Type *Ty, unsigned Depth=0)
 
const SCEVgetZeroExtendExprImpl (const SCEV *Op, Type *Ty, unsigned Depth=0)
 
const SCEVgetSignExtendExpr (const SCEV *Op, Type *Ty, unsigned Depth=0)
 
const SCEVgetSignExtendExprImpl (const SCEV *Op, Type *Ty, unsigned Depth=0)
 
const SCEVgetCastExpr (SCEVTypes Kind, const SCEV *Op, Type *Ty)
 
const SCEVgetAnyExtendExpr (const SCEV *Op, Type *Ty)
 getAnyExtendExpr - Return a SCEV for the given operand extended with unspecified bits out to the given type.
 
const SCEVgetAddExpr (SmallVectorImpl< const SCEV * > &Ops, SCEV::NoWrapFlags Flags=SCEV::FlagAnyWrap, unsigned Depth=0)
 Get a canonical add expression, or something simpler if possible.
 
const SCEVgetAddExpr (const SCEV *LHS, const SCEV *RHS, SCEV::NoWrapFlags Flags=SCEV::FlagAnyWrap, unsigned Depth=0)
 
const SCEVgetAddExpr (const SCEV *Op0, const SCEV *Op1, const SCEV *Op2, SCEV::NoWrapFlags Flags=SCEV::FlagAnyWrap, unsigned Depth=0)
 
const SCEVgetMulExpr (SmallVectorImpl< const SCEV * > &Ops, SCEV::NoWrapFlags Flags=SCEV::FlagAnyWrap, unsigned Depth=0)
 Get a canonical multiply expression, or something simpler if possible.
 
const SCEVgetMulExpr (const SCEV *LHS, const SCEV *RHS, SCEV::NoWrapFlags Flags=SCEV::FlagAnyWrap, unsigned Depth=0)
 
const SCEVgetMulExpr (const SCEV *Op0, const SCEV *Op1, const SCEV *Op2, SCEV::NoWrapFlags Flags=SCEV::FlagAnyWrap, unsigned Depth=0)
 
const SCEVgetUDivExpr (const SCEV *LHS, const SCEV *RHS)
 Get a canonical unsigned division expression, or something simpler if possible.
 
const SCEVgetUDivExactExpr (const SCEV *LHS, const SCEV *RHS)
 Get a canonical unsigned division expression, or something simpler if possible.
 
const SCEVgetURemExpr (const SCEV *LHS, const SCEV *RHS)
 Represents an unsigned remainder expression based on unsigned division.
 
const SCEVgetAddRecExpr (const SCEV *Start, const SCEV *Step, const Loop *L, SCEV::NoWrapFlags Flags)
 Get an add recurrence expression for the specified loop.
 
const SCEVgetAddRecExpr (SmallVectorImpl< const SCEV * > &Operands, const Loop *L, SCEV::NoWrapFlags Flags)
 Get an add recurrence expression for the specified loop.
 
const SCEVgetAddRecExpr (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 SCEVgetGEPExpr (GEPOperator *GEP, const SmallVectorImpl< const SCEV * > &IndexExprs)
 Returns an expression for a GEP.
 
const SCEVgetAbsExpr (const SCEV *Op, bool IsNSW)
 
const SCEVgetMinMaxExpr (SCEVTypes Kind, SmallVectorImpl< const SCEV * > &Operands)
 
const SCEVgetSequentialMinMaxExpr (SCEVTypes Kind, SmallVectorImpl< const SCEV * > &Operands)
 
const SCEVgetSMaxExpr (const SCEV *LHS, const SCEV *RHS)
 
const SCEVgetSMaxExpr (SmallVectorImpl< const SCEV * > &Operands)
 
const SCEVgetUMaxExpr (const SCEV *LHS, const SCEV *RHS)
 
const SCEVgetUMaxExpr (SmallVectorImpl< const SCEV * > &Operands)
 
const SCEVgetSMinExpr (const SCEV *LHS, const SCEV *RHS)
 
const SCEVgetSMinExpr (SmallVectorImpl< const SCEV * > &Operands)
 
const SCEVgetUMinExpr (const SCEV *LHS, const SCEV *RHS, bool Sequential=false)
 
const SCEVgetUMinExpr (SmallVectorImpl< const SCEV * > &Operands, bool Sequential=false)
 
const SCEVgetUnknown (Value *V)
 
const SCEVgetCouldNotCompute ()
 
const SCEVgetZero (Type *Ty)
 Return a SCEV for the constant 0 of a specific type.
 
const SCEVgetOne (Type *Ty)
 Return a SCEV for the constant 1 of a specific type.
 
const SCEVgetPowerOfTwo (Type *Ty, unsigned Power)
 Return a SCEV for the constant Power of two.
 
const SCEVgetMinusOne (Type *Ty)
 Return a SCEV for the constant -1 of a specific type.
 
const SCEVgetSizeOfExpr (Type *IntTy, TypeSize Size)
 Return an expression for a TypeSize.
 
const SCEVgetSizeOfExpr (Type *IntTy, Type *AllocTy)
 Return an expression for the alloc size of AllocTy that is type IntTy.
 
const SCEVgetStoreSizeOfExpr (Type *IntTy, Type *StoreTy)
 Return an expression for the store size of StoreTy that is type IntTy.
 
const SCEVgetOffsetOfExpr (Type *IntTy, StructType *STy, unsigned FieldNo)
 Return an expression for offsetof on the given field with type IntTy.
 
const SCEVgetNegativeSCEV (const SCEV *V, SCEV::NoWrapFlags Flags=SCEV::FlagAnyWrap)
 Return the SCEV object corresponding to -V.
 
const SCEVgetNotSCEV (const SCEV *V)
 Return the SCEV object corresponding to ~V.
 
const SCEVgetMinusSCEV (const SCEV *LHS, const SCEV *RHS, SCEV::NoWrapFlags Flags=SCEV::FlagAnyWrap, unsigned Depth=0)
 Return LHS-RHS.
 
const SCEVgetUDivCeilSCEV (const SCEV *N, const SCEV *D)
 Compute ceil(N / D).
 
const SCEVgetTruncateOrZeroExtend (const SCEV *V, Type *Ty, unsigned Depth=0)
 Return a SCEV corresponding to a conversion of the input value to the specified type.
 
const SCEVgetTruncateOrSignExtend (const SCEV *V, Type *Ty, unsigned Depth=0)
 Return a SCEV corresponding to a conversion of the input value to the specified type.
 
const SCEVgetNoopOrZeroExtend (const SCEV *V, Type *Ty)
 Return a SCEV corresponding to a conversion of the input value to the specified type.
 
const SCEVgetNoopOrSignExtend (const SCEV *V, Type *Ty)
 Return a SCEV corresponding to a conversion of the input value to the specified type.
 
const SCEVgetNoopOrAnyExtend (const SCEV *V, Type *Ty)
 Return a SCEV corresponding to a conversion of the input value to the specified type.
 
const SCEVgetTruncateOrNoop (const SCEV *V, Type *Ty)
 Return a SCEV corresponding to a conversion of the input value to the specified type.
 
const SCEVgetUMaxFromMismatchedTypes (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 SCEVgetUMinFromMismatchedTypes (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 SCEVgetUMinFromMismatchedTypes (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 SCEVgetPointerBase (const SCEV *V)
 Transitively follow the chain of pointer-type operands until reaching a SCEV that does not have a single pointer operand.
 
const SCEVremovePointerBase (const SCEV *S)
 Compute an expression equivalent to S - getPointerBase(S).
 
const SCEVgetSCEVAtScope (const SCEV *S, const Loop *L)
 Return a SCEV expression for the specified value at the specified scope in the program.
 
const SCEVgetSCEVAtScope (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 SCEVgetTripCountFromExitCount (const SCEV *ExitCount)
 A version of getTripCountFromExitCount below which always picks an evaluation type which can not result in overflow.
 
const SCEVgetTripCountFromExitCount (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.
 
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 SCEVgetExitCount (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 SCEVgetBackedgeTakenCount (const Loop *L, ExitCountKind Kind=Exact)
 If the specified loop has a predictable backedge-taken count, return it, otherwise return a SCEVCouldNotCompute object.
 
const SCEVgetPredicatedBackedgeTakenCount (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 SCEVgetConstantMaxBackedgeTakenCount (const Loop *L)
 When successful, this returns a SCEVConstant that is greater than or equal to (i.e.
 
const SCEVgetSymbolicMaxBackedgeTakenCount (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 forgetLcssaPhiWithNewPredecessor (Loop *L, PHINode *V)
 Forget LCSSA phi node V of loop L to which a new predecessor was added, such that it may no longer be trivial.
 
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< boolevaluatePredicate (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< boolevaluatePredicateAt (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< MonotonicPredicateTypegetMonotonicPredicateType (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< LoopInvariantPredicategetLoopInvariantPredicate (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< LoopInvariantPredicategetLoopInvariantExitCondDuringFirstIterations (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< LoopInvariantPredicategetLoopInvariantExitCondDuringFirstIterationsImpl (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 SCEVgetElementSize (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 DataLayoutgetDataLayout () const
 Return the DataLayout associated with the module this SCEV instance is operating on.
 
const SCEVPredicategetEqualPredicate (const SCEV *LHS, const SCEV *RHS)
 
const SCEVPredicategetComparePredicate (ICmpInst::Predicate Pred, const SCEV *LHS, const SCEV *RHS)
 
const SCEVPredicategetWrapPredicate (const SCEVAddRecExpr *AR, SCEVWrapPredicate::IncrementWrapFlags AddedFlags)
 
const SCEVrewriteUsingPredicate (const SCEV *S, const Loop *L, const SCEVPredicate &A)
 Re-writes the SCEV according to the Predicates in A.
 
const SCEVAddRecExprconvertSCEVToAddRecWithPredicates (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< APIntcomputeConstantDifference (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 SCEVapplyLoopGuards (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.
 
void getPoisonGeneratingValues (SmallPtrSetImpl< const Value * > &Result, const SCEV *S)
 Return the set of Values that, if poison, will definitively result in S being poison as well.
 
bool canReuseInstruction (const SCEV *S, Instruction *I, SmallVectorImpl< Instruction * > &DropPoisonGeneratingInsts)
 Check whether it is poison-safe to represent the expression S using the instruction I.
 

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

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

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 861 of file ScalarEvolution.h.

◆ 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

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 1162 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 13402 of file ScalarEvolution.cpp.

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

◆ ScalarEvolution() [2/2]

ScalarEvolution::ScalarEvolution ( ScalarEvolution &&  Arg)

Definition at line 13423 of file ScalarEvolution.cpp.

◆ ~ScalarEvolution()

ScalarEvolution::~ScalarEvolution ( )

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 15039 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(), getSmallConstantTripMultiple(), isSafeDecreasingBound(), and isSafeIncreasingBound().

◆ canReuseInstruction()

bool ScalarEvolution::canReuseInstruction ( const SCEV S,
Instruction I,
SmallVectorImpl< Instruction * > &  DropPoisonGeneratingInsts 
)

◆ clearFlags()

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

Definition at line 481 of file ScalarEvolution.h.

Referenced by getMulExpr().

◆ 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 11883 of file ScalarEvolution.cpp.

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

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 8876 of file ScalarEvolution.cpp.

Referenced by optimizeLoopExitWithUnknownExitCount().

◆ containsAddRecurrence()

bool ScalarEvolution::containsAddRecurrence ( const SCEV S)

◆ 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 13351 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 13342 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 14597 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 5687 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 13879 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 10887 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 10906 of file ScalarEvolution.cpp.

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

Referenced by createReplacement().

◆ forgetAllLoops()

void ScalarEvolution::forgetAllLoops ( )

◆ forgetBlockAndLoopDispositions()

void ScalarEvolution::forgetBlockAndLoopDispositions ( Value V = nullptr)

◆ forgetLcssaPhiWithNewPredecessor()

void ScalarEvolution::forgetLcssaPhiWithNewPredecessor ( Loop L,
PHINode V 
)

Forget LCSSA phi node V of loop L to which a new predecessor was added, such that it may no longer be trivial.

Definition at line 8480 of file ScalarEvolution.cpp.

References llvm::CallingConv::C, forgetValue(), getExistingSCEV(), llvm::SCEVAddRecExpr::getLoop(), I, isSCEVable(), llvm::SmallVectorTemplateBase< T, bool >::push_back(), and llvm::visitAll().

Referenced by llvm::InnerLoopVectorizer::fixVectorizedLoop().

◆ forgetLoop()

void ScalarEvolution::forgetLoop ( const Loop L)

◆ 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 8518 of file ScalarEvolution.cpp.

◆ forgetTopmostLoop()

void ScalarEvolution::forgetTopmostLoop ( const Loop L)

◆ 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 8465 of file ScalarEvolution.cpp.

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

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

◆ getAbsExpr()

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

◆ 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 585 of file ScalarEvolution.h.

References llvm::Depth, 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 591 of file ScalarEvolution.h.

References llvm::Depth, 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 2517 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, 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::isPointerTy(), 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(), calculateRtStride(), calculateSubRanges(), llvm::calculateUpperBound(), llvm::LoopVectorizationCostModel::computeMaxVF(), countToEliminateCompares(), createNodeForSelectViaUMinSeq(), llvm::SCEVAddRecExpr::evaluateAtIteration(), ExtractImmediate(), ExtractSymbol(), findForkedSCEVs(), getAddExpr(), 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(), llvm::LoopStructure::parseLoopStructure(), removePointerBase(), llvm::LoopConstrainer::run(), 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 
)

◆ getAddRecExpr() [2/3]

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

Definition at line 619 of file ScalarEvolution.h.

References getAddRecExpr(), and Operands.

◆ getAddRecExpr() [3/3]

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

◆ getAnyExtendExpr()

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

◆ 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 8283 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 13805 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 
)

◆ getComparePredicate()

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

◆ getConstant() [1/3]

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

Definition at line 490 of file ScalarEvolution.cpp.

References getConstant(), and getContext().

◆ getConstant() [2/3]

const SCEV * ScalarEvolution::getConstant ( ConstantInt V)

◆ getConstant() [3/3]

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

Definition at line 495 of file ScalarEvolution.cpp.

References 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 903 of file ScalarEvolution.h.

References ConstantMaximum, and getBackedgeTakenCount().

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

◆ getConstantMultiple()

APInt ScalarEvolution::getConstantMultiple ( const SCEV S)

Returns the max constant multiple of S.

Definition at line 6367 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 ( )

◆ getDataLayout()

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

◆ 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 4482 of file ScalarEvolution.cpp.

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

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

◆ getElementCount()

const SCEV * ScalarEvolution::getElementCount ( Type Ty,
ElementCount  EC 
)

Definition at line 512 of file ScalarEvolution.cpp.

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

Referenced by llvm::VPlanTransforms::optimizeForVFAndUF().

◆ getElementSize()

const SCEV * ScalarEvolution::getElementSize ( Instruction Inst)

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

Definition at line 13360 of file ScalarEvolution.cpp.

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

◆ getEqualPredicate()

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

◆ getExistingSCEV()

const SCEV * ScalarEvolution::getExistingSCEV ( Value V)

◆ 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 8263 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 3748 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 13706 of file ScalarEvolution.cpp.

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

Referenced by hasComputableLoopEvolution(), llvm::hasIterationCountInvariantInParent(), isLoopInvariant(), llvm::LoopStructure::parseLoopStructure(), 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 11079 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 
)

◆ 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 1006 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 
)

◆ 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 6383 of file ScalarEvolution.cpp.

References 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 670 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 
)

◆ 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 10930 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 600 of file ScalarEvolution.h.

References llvm::Depth, 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 606 of file ScalarEvolution.h.

References llvm::Depth, 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 3112 of file ScalarEvolution.cpp.

References llvm::Add, llvm::append_range(), assert(), llvm::SmallVectorTemplateCommon< T, typename >::begin(), Choose(), clearFlags(), llvm::ConstantRange::contains(), containsConstantInAddMulChain(), llvm::Depth, llvm::SmallVectorBase< Size_T >::empty(), llvm::SmallVectorImpl< T >::erase(), llvm::SCEV::FlagAnyWrap, llvm::SCEV::FlagNSW, llvm::SCEV::FlagNUW, llvm::SCEV::FlagNW, getAddExpr(), getAddRecExpr(), getConstant(), llvm::SCEVAddRecExpr::getLoop(), getMulExpr(), llvm::SCEVNAryExpr::getNoWrapFlags(), llvm::SCEVNAryExpr::getNumOperands(), llvm::SCEVNAryExpr::getOperand(), llvm::APInt::getSignedMinValue(), getSignedRange(), getSignedRangeMin(), llvm::SCEVAddRecExpr::getType(), getType(), getTypeSizeInBits(), getZero(), GroupByComplexity(), hasFlags(), hasHugeExpression(), Idx, isAvailableAtLoopEntry(), llvm::Type::isPointerTy(), LHS, llvm::ConstantRange::makeGuaranteedNoWrapRegion(), maskFlags(), MaxAddRecSize, MaxArithDepth, llvm::Mul, MulOpsInlineThreshold, llvm::OverflowingBinaryOperator::NoSignedWrap, 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(), calculateRtStride(), CollectAddOperandsWithScales(), CollectSubexprs(), llvm::IndexedReference::computeRefCost(), DoInitialMatch(), llvm::SCEVAddRecExpr::evaluateAtIteration(), findArrayDimensionsRec(), findForkedSCEVs(), getAddExpr(), getElementCount(), 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 
)

◆ getNonZeroConstantMultiple()

APInt ScalarEvolution::getNonZeroConstantMultiple ( const SCEV S)

◆ 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 4778 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 4766 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 4754 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)

◆ getOffsetOfExpr()

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

◆ getOne()

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

◆ 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 4847 of file ScalarEvolution.cpp.

References llvm::Add, and assert().

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

◆ getPoisonGeneratingValues()

void ScalarEvolution::getPoisonGeneratingValues ( SmallPtrSetImpl< const Value * > &  Result,
const SCEV S 
)

Return the set of Values that, if poison, will definitively result in S being poison as well.

The returned set may be incomplete, i.e. there can be additional Values that also result in S being poison.

Definition at line 4186 of file ScalarEvolution.cpp.

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

Referenced by canReuseInstruction().

◆ getPowerOfTwo()

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

Return a SCEV for the constant Power of two.

Definition at line 664 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 8278 of file ScalarEvolution.cpp.

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

◆ getPtrToIntExpr()

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

◆ 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 4571 of file ScalarEvolution.cpp.

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

Referenced by llvm::RecurrenceDescriptor::AddReductionVar(), llvm::IVUsers::AddUsersIfInteresting(), llvm::SCEVAAResult::alias(), llvm::analyzeICmp(), applyLoopGuards(), calculateRtStride(), calculateSubRanges(), canFoldTermCondOfLoop(), canOverlap(), canTailPredicateLoop(), countToEliminateCompares(), createNodeForSelectViaUMinSeq(), DbgGatherSalvagableDVI(), DbgRewriteSalvageableDVIs(), llvm::DependenceInfo::depends(), detectShiftUntilZeroIdiom(), DoInitialMatch(), llvm::AlignmentFromAssumptionsPass::extractAlignmentInfo(), findForkedSCEVs(), findIVOperand(), FindLoopCounter(), llvm::formLCSSAForInstructions(), genLoopLimit(), getAddressAccessSCEV(), llvm::PredicatedScalarEvolution::getAsAddRec(), llvm::Loop::LoopBounds::getBounds(), getBoundsCheckCond(), getFalkorUnrollingPreferences(), getGEPExpr(), llvm::getIndexExpressionsFromGEP(), GetInductionVariable(), getNewAlignment(), llvm::getPointersDiff(), llvm::IVUsers::getReplacementExpr(), llvm::PredicatedScalarEvolution::getSCEV(), getSCEVAtScope(), llvm::DependenceInfo::getSplitIteration(), getStrengthenedNoWrapFlagsFromBinOp(), getStrideFromPointer(), llvm::SCEVExpander::hasRelatedExistingExpansion(), llvm::isDereferenceableAndAlignedInLoop(), isExistingPhi(), isHighCostExpansion(), llvm::InductionDescriptor::isInductionPHI(), llvm::LoopAccessInfo::isInvariant(), llvm::LoopVectorizationLegality::isInvariantAddressOfReduction(), isLoopCounter(), isLoopVariantIndirectAddress(), isProfitableChain(), isSimpleIVUser(), llvm::LoopVectorizationLegality::isUniform(), llvm::LoopStructure::parseLoopStructure(), print(), llvm::PredicatedScalarEvolution::print(), llvm::AlignmentFromAssumptionsPass::processAssumption(), llvm::SCEVExpander::replaceCongruentIVs(), llvm::rewriteLoopExitValues(), llvm::LoopVectorizationCostModel::setVectorizedCallDecision(), 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 9722 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 10043 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 995 of file ScalarEvolution.h.

Referenced by getMulExpr(), 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 1005 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 1000 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 
)

◆ getSignExtendExprImpl()

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

◆ 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 4415 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 4408 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 8205 of file ScalarEvolution.cpp.

References getConstantMaxBackedgeTakenCount(), and getConstantTripCount().

Referenced by canFoldTermCondOfLoop(), llvm::LoopVectorizationCostModel::computeMaxVF(), 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 8189 of file ScalarEvolution.cpp.

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

Referenced by llvm::CacheCost::CacheCost(), llvm::LoopVectorizationCostModel::computeMaxVF(), llvm::HexagonTTIImpl::getPeelingPreferences(), getSmallBestKnownTC(), llvm::PPCTTIImpl::isHardwareLoopProfitable(), llvm::LoopVectorizationCostModel::selectInterleaveCount(), 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 8195 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 8211 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 8254 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 8225 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 
)

◆ getSMaxExpr() [2/2]

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

Definition at line 4372 of file ScalarEvolution.cpp.

References getMinMaxExpr(), and llvm::scSMaxExpr.

◆ getSMinExpr() [1/2]

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

◆ getSMinExpr() [2/2]

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

Definition at line 4391 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 4419 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 2382 of file ScalarEvolution.cpp.

References llvm::SCEV::FlagAnyWrap, llvm::SCEV::FlagNSW, llvm::SCEV::FlagNUW, 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 911 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 8134 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 8145 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 4790 of file ScalarEvolution.cpp.

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

Referenced by canBeCheaplyTransformed(), and getAnyExtendExpr().

◆ 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 4741 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 
)

◆ getTypeSizeInBits()

uint64_t ScalarEvolution::getTypeSizeInBits ( Type Ty) const

◆ 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 12653 of file ScalarEvolution.cpp.

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

◆ 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 3599 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 calculateRtStride(), getUDivExactExpr(), and SolveLinEquationWithOverflow().

◆ getUDivExpr()

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

◆ getUMaxExpr() [1/2]

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

◆ getUMaxExpr() [2/2]

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

Definition at line 4381 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 4801 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 
)

◆ getUMinExpr() [2/2]

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

◆ 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 4814 of file ScalarEvolution.cpp.

References getUMinFromMismatchedTypes(), LHS, and RHS.

Referenced by createReplacement(), 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 4822 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 4435 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 979 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 989 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 984 of file ScalarEvolution.h.

References llvm::ConstantRange::getUnsignedMin().

Referenced by isKnownNonZero(), and SimplifyICmpOperands().

◆ getURemExpr()

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

◆ getVScale()

const SCEV * ScalarEvolution::getVScale ( Type Ty)

Definition at line 500 of file ScalarEvolution.cpp.

References llvm::scVScale.

Referenced by getElementCount(), and getSizeOfExpr().

◆ getWiderType()

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

◆ getWrapPredicate()

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

◆ getZero()

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

◆ 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 
)

◆ 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 13800 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 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 13477 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 13887 of file ScalarEvolution.cpp.

References llvm::SCEVExprContains().

◆ instructionCouldExistWithOperands()

bool ScalarEvolution::instructionCouldExistWithOperands ( 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 4497 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 
)

◆ isAvailableAtLoopEntry()

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

◆ 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 8296 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 
)

◆ isKnownNegative()

bool ScalarEvolution::isKnownNegative ( const SCEV S)

◆ isKnownNonNegative()

bool ScalarEvolution::isKnownNonNegative ( const SCEV S)

◆ isKnownNonPositive()

bool ScalarEvolution::isKnownNonPositive ( const SCEV S)

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

Definition at line 10798 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 10802 of file ScalarEvolution.cpp.

References getUnsignedRangeMin(), and isKnownNonZero().

Referenced by breakBackedgeIfNotTaken(), canFoldTermCondOfLoop(), and isKnownNonZero().

◆ 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 10921 of file ScalarEvolution.cpp.

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

Referenced by getZeroExtendExprImpl().

◆ isKnownPositive()

bool ScalarEvolution::isKnownPositive ( const SCEV S)

◆ isKnownPredicate()

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

◆ 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 10897 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:

  1. Collect set S all loops on which either LHS or RHS depend.
  2. 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 10822 of file ScalarEvolution.cpp.

References assert(), llvm::DominatorTree::dominates(), llvm::SmallPtrSetImplBase::empty(), getCouldNotCompute(), llvm::LoopBase< BlockT, LoopT >::getHeader(), isAvailableAtLoopEntry(), isLoopBackedgeGuardedByCond(), isLoopEntryGuardedByCond(), LHS, llvm::max_element(), llvm::DominatorTreeBase< NodeT, IsPostDom >::properlyDominates(), RHS, and SplitIntoInitAndPostInc().

Referenced by isKnownPredicate().

◆ isLoopBackedgeGuardedByCond()

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

◆ isLoopEntryGuardedByCond()

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

◆ isLoopInvariant()

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

◆ isSCEVable()

bool ScalarEvolution::isSCEVable ( Type Ty) const

◆ 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 1304 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 7419 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.

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

◆ print()

void ScalarEvolution::print ( raw_ostream OS) const

◆ 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 13883 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 
)

◆ removePointerBase()

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

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

Definition at line 4649 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 14592 of file ScalarEvolution.cpp.

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

◆ setFlags()

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

◆ 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 6397 of file ScalarEvolution.cpp.

References 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 
)

◆ 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 10811 of file ScalarEvolution.cpp.

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

Referenced by isKnownViaInduction().

◆ verify()

void ScalarEvolution::verify ( ) const

◆ willNotOverflow()

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

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 1362 of file ScalarEvolution.h.

◆ SCEVExpander

friend class SCEVExpander
friend

Definition at line 1363 of file ScalarEvolution.h.

◆ SCEVUnknown

friend class SCEVUnknown
friend

Definition at line 1364 of file ScalarEvolution.h.

Referenced by getUnknown().


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