LLVM: llvm::InductionDescriptor Class Reference (original) (raw)

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

#include "[llvm/Analysis/IVDescriptors.h](IVDescriptors%5F8h%5Fsource.html)"

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
LLVM_ABI 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.
ArrayRef< Instruction * > getCastInsts () const
Returns an ArrayRef 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 LLVM_ABI 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 LLVM_ABI 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 LLVM_ABI 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.

A struct for saving information about induction variables.

Definition at line 402 of file IVDescriptors.h.

◆ 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 405 of file IVDescriptors.h.

llvm::InductionDescriptor::InductionDescriptor ( ) default

◆ getCastInsts()

◆ getConstIntStepValue()

ConstantInt * InductionDescriptor::getConstIntStepValue ( ) const

◆ getExactFPMathInst()

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

◆ getInductionBinOp()

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

◆ getInductionOpcode()

◆ getKind()

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

◆ getStartValue()

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

◆ getStep()

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

◆ isFPInductionPHI()

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 1460 of file IVDescriptors.cpp.

References assert(), llvm::LoopBase< BlockT, LoopT >::contains(), D(), llvm::dyn_cast(), 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]

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 1618 of file IVDescriptors.cpp.

References D(), llvm::dbgs(), llvm::dyn_cast(), llvm::PredicatedScalarEvolution::getAsAddRec(), getCastsForInductionPHI(), llvm::PredicatedScalarEvolution::getSCEV(), llvm::PredicatedScalarEvolution::getSE(), InductionDescriptor(), 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]

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 1662 of file IVDescriptors.cpp.

References assert(), D(), llvm::dbgs(), llvm::dyn_cast(), llvm::LoopBase< BlockT, LoopT >::getHeader(), llvm::LoopBase< BlockT, LoopT >::getLoopLatch(), llvm::LoopBase< BlockT, LoopT >::getLoopPreheader(), llvm::ScalarEvolution::getSCEV(), IK_IntInduction, IK_PtrInduction, InductionDescriptor(), llvm::Type::isIntegerTy(), llvm::Type::isPointerTy(), llvm::ScalarEvolution::isSCEVable(), LLVM_DEBUG, llvm::SCEVPatternMatch::m_SCEV(), llvm::SCEVPatternMatch::m_scev_AffineAddRec(), llvm::SCEVPatternMatch::m_SpecificLoop(), and llvm::PatternMatch::match().

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: