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.

Value *	getStartValue () const

InductionKind	getKind () const

const SCEV *	getStep () const

BinaryOperator *	getInductionBinOp () const

ConstantInt *	getConstIntStepValue () const

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

Instruction::BinaryOps	getInductionOpcode () const
	Returns binary opcode of the induction operator.

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.

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`.

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`.

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.

Detailed Description

A struct for saving information about induction variables.

Definition at line 334 of file IVDescriptors.h.

Member Enumeration Documentation

◆ InductionKind

enum llvm::InductionDescriptor::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.
IK_FpInduction	Floating point induction variable.

Definition at line 337 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 403 of file IVDescriptors.h.

Referenced by llvm::LoopVectorizationCostModel::collectValuesToIgnore().

◆ getConstIntStepValue()

ConstantInt * InductionDescriptor::getConstIntStepValue ( ) const

Definition at line 1305 of file IVDescriptors.cpp.

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

◆ 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 387 of file IVDescriptors.h.

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

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

◆ getInductionBinOp()

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

inline

Definition at line 351 of file IVDescriptors.h.

Referenced by llvm::Loop::LoopBounds::getBounds().

◆ getInductionOpcode()

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

inline

Returns binary opcode of the induction operator.

Definition at line 395 of file IVDescriptors.h.

References llvm::BinaryOperator::getOpcode().

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

◆ getKind()

InductionKind llvm::InductionDescriptor::getKind ( ) const

inline

Definition at line 349 of file IVDescriptors.h.

◆ getStartValue()

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

inline

Definition at line 348 of file IVDescriptors.h.

Referenced by createWidenInductionRecipes(), llvm::Loop::LoopBounds::getBounds(), and llvm::Loop::isCanonical().

◆ getStep()

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

inline

Definition at line 350 of file IVDescriptors.h.

Referenced by createWidenInductionRecipes(), llvm::Loop::LoopBounds::getBounds(), and llvm::Loop::isAuxiliaryInductionVariable().

◆ isFPInductionPHI()

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

static

Returns true if Phi is a floating point induction in the loop L.

If Phi is an induction, the induction descriptor D will contain the data describing this induction.

Definition at line 1311 of file IVDescriptors.cpp.

References assert(), llvm::LoopBase< BlockT, LoopT >::contains(), D, llvm::LoopBase< BlockT, LoopT >::getHeader(), llvm::BinaryOperator::getOpcode(), llvm::User::getOperand(), llvm::ScalarEvolution::getUnknown(), I, IK_FpInduction, and InductionDescriptor().

Referenced by isInductionPHI().

◆ 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 1469 of file IVDescriptors.cpp.

References D, llvm::dbgs(), llvm::PredicatedScalarEvolution::getAsAddRec(), getCastsForInductionPHI(), llvm::PredicatedScalarEvolution::getSCEV(), llvm::PredicatedScalarEvolution::getSE(), 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. Since Induction Phis can only be present inside loop headers, the function will assert if it is passed a Phi whose parent is not the loop header. 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 1513 of file IVDescriptors.cpp.

References assert(), D, llvm::dbgs(), llvm::LoopBase< BlockT, LoopT >::getHeader(), llvm::SCEVAddRecExpr::getLoop(), llvm::LoopBase< BlockT, LoopT >::getLoopLatch(), llvm::LoopBase< BlockT, LoopT >::getLoopPreheader(), llvm::ScalarEvolution::getSCEV(), llvm::SCEVAddRecExpr::getStepRecurrence(), IK_IntInduction, IK_PtrInduction, InductionDescriptor(), llvm::Type::isIntegerTy(), llvm::ScalarEvolution::isLoopInvariant(), llvm::Type::isPointerTy(), llvm::ScalarEvolution::isSCEVable(), and LLVM_DEBUG.

Referenced by checkIsIndPhi(), 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:

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

Public Types

Public Member Functions

Static Public Member Functions

Detailed Description

Member Enumeration Documentation

◆ InductionKind

Constructor & Destructor Documentation

◆ InductionDescriptor()

Member Function Documentation

◆ getCastInsts()

◆ getConstIntStepValue()

◆ getExactFPMathInst()

◆ getInductionBinOp()

◆ getInductionOpcode()

◆ getKind()

◆ getStartValue()

◆ getStep()

◆ isFPInductionPHI()

◆ isInductionPHI() [1/2]

◆ isInductionPHI() [2/2]