LLVM  14.0.0git
Public Types | Public Member Functions | Static Public Member Functions | List of all members
llvm::InductionDescriptor Class Reference

A struct for saving information about induction variables. More...

#include "llvm/Analysis/IVDescriptors.h"

Public Types

enum  InductionKind { IK_NoInduction, IK_IntInduction, IK_PtrInduction, IK_FpInduction }
 This enum represents the kinds of inductions that we support. More...
 

Public Member Functions

 InductionDescriptor ()=default
 Default constructor - creates an invalid induction. More...
 
ValuegetStartValue () const
 
InductionKind getKind () const
 
const SCEVgetStep () const
 
BinaryOperatorgetInductionBinOp () const
 
ConstantIntgetConstIntStepValue () const
 
InstructiongetExactFPMathInst ()
 Returns floating-point induction operator that does not allow reassociation (transforming the induction requires an override of normal floating-point rules). More...
 
Instruction::BinaryOps getInductionOpcode () const
 Returns binary opcode of the induction operator. More...
 
TypegetElementType () const
 
const SmallVectorImpl< Instruction * > & getCastInsts () const
 Returns a reference to the type cast instructions in the induction update chain, that are redundant when guarded with a runtime SCEV overflow check. More...
 

Static Public Member Functions

static bool isInductionPHI (PHINode *Phi, const Loop *L, ScalarEvolution *SE, InductionDescriptor &D, const SCEV *Expr=nullptr, SmallVectorImpl< Instruction * > *CastsToIgnore=nullptr)
 Returns true if Phi is an induction in the loop L. More...
 
static bool isFPInductionPHI (PHINode *Phi, const Loop *L, ScalarEvolution *SE, InductionDescriptor &D)
 Returns true if Phi is a floating point induction in the loop L. More...
 
static bool isInductionPHI (PHINode *Phi, const Loop *L, PredicatedScalarEvolution &PSE, InductionDescriptor &D, bool Assume=false)
 Returns true if Phi is a loop L induction, in the context associated with the run-time predicate of PSE. More...
 

Detailed Description

A struct for saving information about induction variables.

Definition at line 289 of file IVDescriptors.h.

Member Enumeration Documentation

◆ InductionKind

This enum represents the kinds of inductions that we support.

Enumerator
IK_NoInduction 

Not an induction variable.

IK_IntInduction 

Integer induction variable. Step = C.

IK_PtrInduction 

Pointer induction var. Step = C / sizeof(elem).

IK_FpInduction 

Floating point induction variable.

Definition at line 292 of file IVDescriptors.h.

Constructor & Destructor Documentation

◆ InductionDescriptor()

llvm::InductionDescriptor::InductionDescriptor ( )
default

Default constructor - creates an invalid induction.

Referenced by isFPInductionPHI(), and isInductionPHI().

Member Function Documentation

◆ getCastInsts()

const SmallVectorImpl<Instruction *>& llvm::InductionDescriptor::getCastInsts ( ) const
inline

Returns a reference to the type cast instructions in the induction update chain, that are redundant when guarded with a runtime SCEV overflow check.

Definition at line 361 of file IVDescriptors.h.

Referenced by llvm::LoopVectorizationPlanner::collectTriviallyDeadInstructions(), and llvm::LoopVectorizationCostModel::collectValuesToIgnore().

◆ getConstIntStepValue()

ConstantInt * InductionDescriptor::getConstIntStepValue ( ) const

Definition at line 1109 of file IVDescriptors.cpp.

Referenced by llvm::Loop::isCanonical().

◆ getElementType()

Type* llvm::InductionDescriptor::getElementType ( ) const
inline

Definition at line 353 of file IVDescriptors.h.

References assert(), and IK_PtrInduction.

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

◆ getExactFPMathInst()

Instruction* llvm::InductionDescriptor::getExactFPMathInst ( )
inline

Returns floating-point induction operator that does not allow reassociation (transforming the induction requires an override of normal floating-point rules).

Definition at line 340 of file IVDescriptors.h.

References llvm::Instruction::hasAllowReassoc(), and IK_FpInduction.

Referenced by llvm::LoopVectorizationLegality::canVectorizeFPMath().

◆ getInductionBinOp()

BinaryOperator* llvm::InductionDescriptor::getInductionBinOp ( ) const
inline

◆ getInductionOpcode()

Instruction::BinaryOps llvm::InductionDescriptor::getInductionOpcode ( ) const
inline

Returns binary opcode of the induction operator.

Definition at line 348 of file IVDescriptors.h.

References llvm::BinaryOperator::getOpcode().

Referenced by llvm::Loop::isAuxiliaryInductionVariable(), and llvm::Loop::isCanonical().

◆ getKind()

InductionKind llvm::InductionDescriptor::getKind ( ) const
inline

◆ getStartValue()

Value* llvm::InductionDescriptor::getStartValue ( ) const
inline

◆ getStep()

const SCEV* llvm::InductionDescriptor::getStep ( ) const
inline

◆ isFPInductionPHI()

bool InductionDescriptor::isFPInductionPHI ( PHINode Phi,
const Loop L,
ScalarEvolution SE,
InductionDescriptor D 
)
static

◆ isInductionPHI() [1/2]

bool InductionDescriptor::isInductionPHI ( PHINode Phi,
const Loop L,
PredicatedScalarEvolution PSE,
InductionDescriptor D,
bool  Assume = false 
)
static

Returns true if Phi is a loop L induction, in the context associated with the run-time predicate of PSE.

If Assume is true, this can add further SCEV predicates to PSE in order to prove that Phi is an induction. If Phi is an induction, D will contain the data describing this induction.

Definition at line 1273 of file IVDescriptors.cpp.

References D, llvm::dbgs(), llvm::PredicatedScalarEvolution::getAsAddRec(), getCastsForInductionPHI(), llvm::PredicatedScalarEvolution::getSCEV(), llvm::PredicatedScalarEvolution::getSE(), llvm::Value::getType(), llvm::Type::isDoubleTy(), llvm::Type::isFloatingPointTy(), llvm::Type::isFloatTy(), isFPInductionPHI(), llvm::Type::isHalfTy(), isInductionPHI(), llvm::Type::isIntegerTy(), llvm::Type::isPointerTy(), and LLVM_DEBUG.

◆ isInductionPHI() [2/2]

bool InductionDescriptor::isInductionPHI ( PHINode Phi,
const Loop L,
ScalarEvolution SE,
InductionDescriptor D,
const SCEV Expr = nullptr,
SmallVectorImpl< Instruction * > *  CastsToIgnore = nullptr 
)
static

Returns true if Phi is an induction in the loop L.

If Phi is an induction, the induction descriptor D will contain the data describing this induction. If by some other means the caller has a better SCEV expression for Phi than the one returned by the ScalarEvolution analysis, it can be passed through Expr. If the def-use chain associated with the phi includes casts (that we know we can ignore under proper runtime checks), they are passed through CastsToIgnore.

Definition at line 1317 of file IVDescriptors.cpp.

References assert(), D, llvm::dbgs(), DL, llvm::ScalarEvolution::getConstant(), llvm::Type::getContext(), llvm::Module::getDataLayout(), llvm::PointerType::getElementType(), llvm::PHINode::getIncomingValueForBlock(), llvm::Type::getInt8Ty(), llvm::SCEVAddRecExpr::getLoop(), llvm::LoopBase< BlockT, LoopT >::getLoopLatch(), llvm::LoopBase< BlockT, LoopT >::getLoopPreheader(), llvm::Instruction::getModule(), llvm::ScalarEvolution::getSCEV(), llvm::ConstantInt::getSExtValue(), llvm::SCEVAddRecExpr::getStepRecurrence(), llvm::ConstantInt::getType(), llvm::Value::getType(), llvm::SCEVConstant::getValue(), IK_IntInduction, IK_PtrInduction, InductionDescriptor(), llvm::Type::isIntegerTy(), llvm::ScalarEvolution::isLoopInvariant(), llvm::PointerType::isOpaque(), llvm::Type::isPointerTy(), llvm::Type::isSized(), LLVM_DEBUG, and llvm::Check::Size.

Referenced by llvm::Loop::LoopBounds::getBounds(), llvm::Loop::getInductionDescriptor(), llvm::Loop::getInductionVariable(), llvm::Loop::isAuxiliaryInductionVariable(), and isInductionPHI().


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