llvm::ConditionalInductionDescriptor Class Reference

Describes a conditional induction variable: an induction variable that is updated only on loop iterations for which a certain predicate is satisfied. More...

#include "llvm/Analysis/IVDescriptors.h"

Public Member Functions
	ConditionalInductionDescriptor ()=default
PHINode *	getHeaderPHI () const
	Returns the header PHI described by this descriptor.
PHINode *	getBackedgePHI () const
	Returns the backedge PHI that selects between StepInst and the HeaderPHI.
Instruction *	getStepInst () const
	Returns the instruction that updates the conditional induction PHI.
const SCEV *	getStartSCEV () const
	Returns a SCEV expression for the initial value of the conditional induction PHI.
const SCEV *	getStepSCEV () const
	Returns a SCEV expression for the step of the conditional induction PHI.
SCEVFlags	getSCEVNoWrapFlags () const
	Returns the SCEV no-wrap flags that apply to StepInst.
LLVM_ABI const SCEV *	getUnconditionalAddRec (ScalarEvolution &SE, const Loop &L) const
	Returns an over-approximation of the conditional induction as a SCEVAddRec assuming the condition is always true.

Static Public Member Functions
static LLVM_ABI bool	isConditionalInductionPHI (PHINode *PN, const Loop *L, ConditionalInductionDescriptor &Desc, ScalarEvolution &SE)
	Returns true if PN is a conditional induction variable in the loop L.

Detailed Description

Describes a conditional induction variable: an induction variable that is updated only on loop iterations for which a certain predicate is satisfied.

Its step must be loop-invariant.

Definition at line 489 of file IVDescriptors.h.

Constructor & Destructor Documentation

ConditionalInductionDescriptor()

llvm::ConditionalInductionDescriptor::ConditionalInductionDescriptor ( )

default

References ConditionalInductionDescriptor(), and LLVM_ABI.

Referenced by ConditionalInductionDescriptor(), and isConditionalInductionPHI().

Member Function Documentation

getBackedgePHI()

PHINode * llvm::ConditionalInductionDescriptor::getBackedgePHI ( ) const

inline

Returns the backedge PHI that selects between StepInst and the HeaderPHI.

Definition at line 504 of file IVDescriptors.h.

Referenced by llvm::collectCompressedPtrs().

getHeaderPHI()

PHINode * llvm::ConditionalInductionDescriptor::getHeaderPHI ( ) const

inline

Returns the header PHI described by this descriptor.

Definition at line 501 of file IVDescriptors.h.

Referenced by llvm::collectCompressedPtrs().

getSCEVNoWrapFlags()

SCEVFlags llvm::ConditionalInductionDescriptor::getSCEVNoWrapFlags ( ) const

inline

Returns the SCEV no-wrap flags that apply to StepInst.

Definition at line 518 of file IVDescriptors.h.

getStartSCEV()

const SCEV * llvm::ConditionalInductionDescriptor::getStartSCEV ( ) const

inline

Returns a SCEV expression for the initial value of the conditional induction PHI.

Definition at line 511 of file IVDescriptors.h.

Referenced by getUnconditionalAddRec().

getStepInst()

Instruction * llvm::ConditionalInductionDescriptor::getStepInst ( ) const

inline

Returns the instruction that updates the conditional induction PHI.

Definition at line 507 of file IVDescriptors.h.

getStepSCEV()

const SCEV * llvm::ConditionalInductionDescriptor::getStepSCEV ( ) const

inline

Returns a SCEV expression for the step of the conditional induction PHI.

This is the value it increments by when the predicate is satisfied.

Definition at line 515 of file IVDescriptors.h.

Referenced by getUnconditionalAddRec().

getUnconditionalAddRec()

const SCEV * ConditionalInductionDescriptor::getUnconditionalAddRec	(	ScalarEvolution &	SE,
		const Loop &	L ) const

Returns an over-approximation of the conditional induction as a SCEVAddRec assuming the condition is always true.

The loop L must be the loop containing the conditional induction.

Definition at line 1812 of file IVDescriptors.cpp.

References assert(), llvm::SCEV::FlagNone, llvm::ScalarEvolution::getAddRecExpr(), getStartSCEV(), and getStepSCEV().

Referenced by llvm::collectCompressedPtrs().

isConditionalInductionPHI()

bool ConditionalInductionDescriptor::isConditionalInductionPHI ( PHINode * PN, const Loop * L, ConditionalInductionDescriptor & Desc, ScalarEvolution & SE )

static

Returns true if PN is a conditional induction variable in the loop L.

If it is, Desc will contain the data describing the PHI.

Definition at line 1733 of file IVDescriptors.cpp.

References llvm::cast(), ConditionalInductionDescriptor(), llvm::dbgs(), llvm::dyn_cast(), llvm::find_singleton(), llvm::SCEV::FlagNone, llvm::SCEV::FlagNSW, llvm::SCEV::FlagNUW, GEP, llvm::ScalarEvolution::getEffectiveSCEVType(), llvm::PHINode::getIncomingValueForBlock(), llvm::ilist_detail::node_parent_access< NodeTy, ParentTy >::getParent(), llvm::ScalarEvolution::getSCEV(), llvm::ScalarEvolution::getTruncateOrSignExtend(), llvm::Value::getType(), llvm::Value::hasOneUse(), llvm::Type::isIntOrPtrTy(), llvm::ScalarEvolution::isKnownNonNegative(), llvm::Type::isPointerTy(), LLVM_DEBUG, llvm::PatternMatch::m_c_Add(), llvm::PatternMatch::m_PtrAdd(), llvm::PatternMatch::m_Specific(), llvm::PatternMatch::m_Value(), llvm::PatternMatch::match(), llvm::ScalarEvolution::setFlags(), and llvm::Value::users().

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

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