llvm::SCEV Class Reference

#include <ScalarEvolution.h>

Inheritance diagram for llvm::SCEV:

Collaboration diagram for llvm::SCEV:

Public Types
enum	NoWrapFlags {   FlagAnyWrap = 0, FlagNW = (1 << 0), FlagNUW = (1 << 1), FlagNSW = (1 << 2),   NoWrapMask = (1 << 3) -1 }

Public Member Functions
	SCEV (const FoldingSetNodeIDRef ID, unsigned SCEVTy)
unsigned	getSCEVType () const
Type *	getType () const
bool	isZero () const
bool	isOne () const
bool	isAllOnesValue () const
bool	isNonConstantNegative () const
void	print (raw_ostream &OS) const
void	dump () const
Public Member Functions inherited from llvm::FoldingSetImpl::Node
	Node ()
void *	getNextInBucket () const
void	SetNextInBucket (void *N)

Protected Attributes
unsigned short	SubclassData

Friends
struct	FoldingSetTrait< SCEV >

Detailed Description

SCEV - This class represents an analyzed expression in the program. These are opaque objects that the client is not allowed to do much with directly.

Definition at line 57 of file ScalarEvolution.h.

Member Enumeration Documentation

enum llvm::SCEV::NoWrapFlags

NoWrapFlags are bitfield indices into SubclassData.

Add and Mul expressions may have no-unsigned-wrap <NUW> or no-signed-wrap <NSW> properties, which are derived from the IR operator. NSW is a misnomer that we use to mean no signed overflow or underflow.

AddRec expression may have a no-self-wraparound <NW> property if the result can never reach the start value. This property is independent of the actual start value and step direction. Self-wraparound is defined purely in terms of the recurrence's loop, step size, and bitwidth. Formally, a recurrence with no self-wraparound satisfies: abs(step) * max-iteration(loop) <= unsigned-max(bitwidth).

Note that NUW and NSW are also valid properties of a recurrence, and either implies NW. For convenience, NW will be set for a recurrence whenever either NUW or NSW are set.

Enumerator
FlagAnyWrap
FlagNW
FlagNUW
FlagNSW
NoWrapMask

Definition at line 94 of file ScalarEvolution.h.

Constructor & Destructor Documentation

llvm::SCEV::SCEV ( const FoldingSetNodeIDRef  ID, unsigned  SCEVTy  )

inlineexplicit

Definition at line 100 of file ScalarEvolution.h.

Member Function Documentation

void SCEV::dump

(

)

const

dump - This method is used for debugging.

Definition at line 132 of file ScalarEvolution.cpp.

References llvm::dbgs(), and print().

unsigned llvm::SCEV::getSCEVType ( ) const

inline

Definition at line 103 of file ScalarEvolution.h.

Referenced by BuildConstantFromSCEV(), llvm::SCEVConstant::classof(), llvm::SCEVCastExpr::classof(), llvm::SCEVTruncateExpr::classof(), llvm::SCEVZeroExtendExpr::classof(), llvm::SCEVSignExtendExpr::classof(), llvm::SCEVNAryExpr::classof(), llvm::SCEVCouldNotCompute::classof(), llvm::SCEVCommutativeExpr::classof(), llvm::SCEVAddExpr::classof(), llvm::SCEVMulExpr::classof(), llvm::SCEVUDivExpr::classof(), llvm::SCEVAddRecExpr::classof(), llvm::SCEVSMaxExpr::classof(), llvm::SCEVUMaxExpr::classof(), llvm::SCEVUnknown::classof(), getExprBase(), getType(), GroupByComplexity(), isHighCostExpansion(), print(), llvm::SCEVVisitor< SCEVExpander, Value * >::visit(), and llvm::SCEVTraversal< SV >::visitAll().

Type * SCEV::getType

(

)

const

getType - Return the LLVM type of this SCEV expression.

Definition at line 249 of file ScalarEvolution.cpp.

References getSCEVType(), llvm_unreachable, llvm::scAddExpr, llvm::scAddRecExpr, llvm::scConstant, llvm::scCouldNotCompute, llvm::scMulExpr, llvm::scSignExtend, llvm::scSMaxExpr, llvm::scTruncate, llvm::scUDivExpr, llvm::scUMaxExpr, llvm::scUnknown, and llvm::scZeroExtend.

Referenced by BinomialCoefficient(), FactorOutConstant(), FindLoopCounter(), genLoopLimit(), llvm::ScalarEvolution::getAddExpr(), llvm::ScalarEvolution::getAnyExtendExpr(), getExactSDiv(), llvm::ScalarEvolution::getMinusSCEV(), llvm::ScalarEvolution::getNegativeSCEV(), llvm::ScalarEvolution::getNoopOrAnyExtend(), llvm::ScalarEvolution::getNoopOrSignExtend(), llvm::ScalarEvolution::getNoopOrZeroExtend(), llvm::ScalarEvolution::getNotSCEV(), getOverflowLimitForStep(), llvm::ScalarEvolution::getPointerBase(), llvm::ScalarEvolution::getSignedRange(), llvm::ScalarEvolution::getSignExtendExpr(), llvm::ScalarEvolution::getSmallConstantTripMultiple(), llvm::ScalarEvolution::getTruncateExpr(), llvm::ScalarEvolution::getTruncateOrNoop(), llvm::ScalarEvolution::getTruncateOrSignExtend(), llvm::ScalarEvolution::getTruncateOrZeroExtend(), llvm::SCEVNAryExpr::getType(), llvm::SCEVAddExpr::getType(), llvm::SCEVUDivExpr::getType(), llvm::ScalarEvolution::getUDivExpr(), llvm::ScalarEvolution::getUMaxFromMismatchedTypes(), llvm::ScalarEvolution::getUMinFromMismatchedTypes(), llvm::ScalarEvolution::getUnsignedRange(), llvm::ScalarEvolution::getZeroExtendExpr(), isHighCostExpansion(), llvm::SCEVExpander::replaceCongruentIVs(), llvm::ScalarEvolution::SimplifyICmpOperands(), and llvm::UnrollRuntimeLoopProlog().

bool SCEV::isAllOnesValue

(

)

const

isAllOnesValue - Return true if the expression is a constant all-ones value.

Definition at line 287 of file ScalarEvolution.cpp.

References llvm::PPCISD::SC.

bool SCEV::isNonConstantNegative

(

)

const

isNonConstantNegative - Return true if the specified scev is negated, but not a constant.

Definition at line 295 of file ScalarEvolution.cpp.

References llvm::dyn_cast(), llvm::SCEVNAryExpr::getOperand(), llvm::SCEVConstant::getValue(), llvm::ConstantInt::getValue(), llvm::APInt::isNegative(), and llvm::PPCISD::SC.

bool SCEV::isOne

(

)

const

isOne - Return true if the expression is a constant one.

Definition at line 281 of file ScalarEvolution.cpp.

References llvm::PPCISD::SC.

Referenced by FactorOutConstant(), FindLoopCounter(), and genLoopLimit().

bool SCEV::isZero

(

)

const

isZero - Return true if the expression is a constant zero.

Definition at line 275 of file ScalarEvolution.cpp.

References llvm::PPCISD::SC.

Referenced by canExpandBackedgeTakenCount(), CollectSubexprs(), FactorOutConstant(), FindLoopCounter(), genLoopLimit(), llvm::ScalarEvolution::getAddRecExpr(), isAlwaysFoldable(), and SplitAddRecs().

void SCEV::print

(

raw_ostream &

OS

)

const

print - Print out the internal representation of this scalar to the specified stream. This should really only be used for debugging purposes.

Definition at line 138 of file ScalarEvolution.cpp.

References FlagNSW, FlagNUW, FlagNW, llvm::LoopBase< N, M >::getHeader(), llvm::SCEVUDivExpr::getLHS(), llvm::SCEVAddRecExpr::getLoop(), llvm::SCEVNAryExpr::getNoWrapFlags(), llvm::SCEVNAryExpr::getNumOperands(), llvm::SCEVCastExpr::getOperand(), llvm::SCEVNAryExpr::getOperand(), llvm::SCEVUDivExpr::getRHS(), getSCEVType(), llvm::SCEVCastExpr::getType(), llvm::SCEVUnknown::getValue(), I, llvm::SCEVUnknown::isAlignOf(), llvm::SCEVUnknown::isOffsetOf(), llvm::SCEVUnknown::isSizeOf(), llvm_unreachable, llvm::next(), llvm::SCEVNAryExpr::op_begin(), llvm::SCEVNAryExpr::op_end(), llvm::scAddExpr, llvm::scAddRecExpr, llvm::scConstant, llvm::scCouldNotCompute, llvm::scMulExpr, llvm::scSignExtend, llvm::scSMaxExpr, llvm::scTruncate, llvm::scUDivExpr, llvm::scUMaxExpr, llvm::scUnknown, llvm::scZeroExtend, and llvm::WriteAsOperand().

Referenced by dump(), getLoopBackedgeTakenCounts(), llvm::operator<<(), and llvm::ScalarEvolution::print().

Friends And Related Function Documentation

friend struct FoldingSetTrait< SCEV >

friend

Definition at line 58 of file ScalarEvolution.h.

Member Data Documentation

unsigned short llvm::SCEV::SubclassData

protected

SubclassData - This field is initialized to zero and may be used in subclasses to store miscellaneous information.

Definition at line 70 of file ScalarEvolution.h.

Referenced by llvm::SCEVNAryExpr::getNoWrapFlags(), llvm::SCEVCommutativeExpr::setNoWrapFlags(), and llvm::SCEVAddRecExpr::setNoWrapFlags().

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

• ScalarEvolution.h
• ScalarEvolution.cpp