LLVM 20.0.0git
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llvm::PredicatedScalarEvolution Class Reference

An interface layer with SCEV used to manage how we see SCEV expressions for values in the context of existing predicates. More...

#include "llvm/Analysis/ScalarEvolution.h"

Public Member Functions

 PredicatedScalarEvolution (ScalarEvolution &SE, Loop &L)
 
const SCEVPredicategetPredicate () const
 
const SCEVgetSCEV (Value *V)
 Returns the SCEV expression of V, in the context of the current SCEV predicate.
 
const SCEVgetBackedgeTakenCount ()
 Get the (predicated) backedge count for the analyzed loop.
 
const SCEVgetSymbolicMaxBackedgeTakenCount ()
 Get the (predicated) symbolic max backedge count for the analyzed loop.
 
void addPredicate (const SCEVPredicate &Pred)
 Adds a new predicate.
 
const SCEVAddRecExprgetAsAddRec (Value *V)
 Attempts to produce an AddRecExpr for V by adding additional SCEV predicates.
 
void setNoOverflow (Value *V, SCEVWrapPredicate::IncrementWrapFlags Flags)
 Proves that V doesn't overflow by adding SCEV predicate.
 
bool hasNoOverflow (Value *V, SCEVWrapPredicate::IncrementWrapFlags Flags)
 Returns true if we've proved that V doesn't wrap by means of a SCEV predicate.
 
ScalarEvolutiongetSE () const
 Returns the ScalarEvolution analysis used.
 
 PredicatedScalarEvolution (const PredicatedScalarEvolution &)
 We need to explicitly define the copy constructor because of FlagsMap.
 
void print (raw_ostream &OS, unsigned Depth) const
 Print the SCEV mappings done by the Predicated Scalar Evolution.
 
bool areAddRecsEqualWithPreds (const SCEVAddRecExpr *AR1, const SCEVAddRecExpr *AR2) const
 Check if AR1 and AR2 are equal, while taking into account Equal predicates in Preds.
 

Detailed Description

An interface layer with SCEV used to manage how we see SCEV expressions for values in the context of existing predicates.

We can add new predicates, but we cannot remove them.

This layer has multiple purposes:

Definition at line 2328 of file ScalarEvolution.h.

Constructor & Destructor Documentation

◆ PredicatedScalarEvolution() [1/2]

PredicatedScalarEvolution::PredicatedScalarEvolution ( ScalarEvolution SE,
Loop L 
)

Definition at line 14893 of file ScalarEvolution.cpp.

References llvm::Empty.

◆ PredicatedScalarEvolution() [2/2]

PredicatedScalarEvolution::PredicatedScalarEvolution ( const PredicatedScalarEvolution Init)

We need to explicitly define the copy constructor because of FlagsMap.

Definition at line 15021 of file ScalarEvolution.cpp.

References I.

Member Function Documentation

◆ addPredicate()

void PredicatedScalarEvolution::addPredicate ( const SCEVPredicate Pred)

◆ areAddRecsEqualWithPreds()

bool PredicatedScalarEvolution::areAddRecsEqualWithPreds ( const SCEVAddRecExpr AR1,
const SCEVAddRecExpr AR2 
) const

Check if AR1 and AR2 are equal, while taking into account Equal predicates in Preds.

Definition at line 5693 of file ScalarEvolution.cpp.

References llvm::ScalarEvolution::getEqualPredicate(), llvm::SCEVAddRecExpr::getStart(), and llvm::SCEVAddRecExpr::getStepRecurrence().

Referenced by getCastsForInductionPHI().

◆ getAsAddRec()

const SCEVAddRecExpr * PredicatedScalarEvolution::getAsAddRec ( Value V)

Attempts to produce an AddRecExpr for V by adding additional SCEV predicates.

If we can't transform the expression into an AddRecExpr we return nullptr and not add additional SCEV predicates to the current context.

Definition at line 15006 of file ScalarEvolution.cpp.

References addPredicate(), llvm::ScalarEvolution::convertSCEVToAddRecWithPredicates(), llvm::ScalarEvolution::getSCEV(), getSCEV(), and P.

Referenced by llvm::getPtrStride(), hasComputableBounds(), and llvm::InductionDescriptor::isInductionPHI().

◆ getBackedgeTakenCount()

const SCEV * PredicatedScalarEvolution::getBackedgeTakenCount ( )

◆ getPredicate()

const SCEVPredicate & PredicatedScalarEvolution::getPredicate ( ) const

◆ getSCEV()

const SCEV * PredicatedScalarEvolution::getSCEV ( Value V)

Returns the SCEV expression of V, in the context of the current SCEV predicate.

The order of transformations applied on the expression of V returned by ScalarEvolution is guaranteed to be preserved, even when adding new predicates.

Definition at line 14910 of file ScalarEvolution.cpp.

References llvm::ScalarEvolution::getSCEV(), and llvm::ScalarEvolution::rewriteUsingPredicate().

Referenced by getAddressAccessSCEV(), getAsAddRec(), getCastsForInductionPHI(), llvm::LoopVectorizationCostModel::getInstructionCost(), hasNoOverflow(), llvm::InductionDescriptor::isInductionPHI(), isNoWrap(), isNoWrapAddRec(), llvm::replaceSymbolicStrideSCEV(), setNoOverflow(), and llvm::LoopVectorizationCostModel::setVectorizedCallDecision().

◆ getSE()

ScalarEvolution * llvm::PredicatedScalarEvolution::getSE ( ) const
inline

◆ getSymbolicMaxBackedgeTakenCount()

const SCEV * PredicatedScalarEvolution::getSymbolicMaxBackedgeTakenCount ( )

Get the (predicated) symbolic max backedge count for the analyzed loop.

Definition at line 14939 of file ScalarEvolution.cpp.

References addPredicate(), llvm::ScalarEvolution::getPredicatedSymbolicMaxBackedgeTakenCount(), and P.

Referenced by getStartAndEndForAccess().

◆ hasNoOverflow()

bool PredicatedScalarEvolution::hasNoOverflow ( Value V,
SCEVWrapPredicate::IncrementWrapFlags  Flags 
)

Returns true if we've proved that V doesn't wrap by means of a SCEV predicate.

Definition at line 14990 of file ScalarEvolution.cpp.

References llvm::SCEVWrapPredicate::clearFlags(), llvm::SCEVWrapPredicate::getImpliedFlags(), getSCEV(), II, and llvm::SCEVWrapPredicate::IncrementAnyWrap.

Referenced by isNoWrap(), and isNoWrapAddRec().

◆ print()

void PredicatedScalarEvolution::print ( raw_ostream OS,
unsigned  Depth 
) const

Print the SCEV mappings done by the Predicated Scalar Evolution.

The printed text is indented by Depth.

Definition at line 15030 of file ScalarEvolution.cpp.

References llvm::Depth, llvm::ScalarEvolution::getSCEV(), I, II, llvm::raw_ostream::indent(), llvm::ScalarEvolution::isSCEVable(), and OS.

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

◆ setNoOverflow()

void PredicatedScalarEvolution::setNoOverflow ( Value V,
SCEVWrapPredicate::IncrementWrapFlags  Flags 
)

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