A structure that can hold either a Simple Recurrence or a Conditional Recurrence. More...

Public Member Functions
	RecurrenceInfo (const Loop &L)

	operator bool () const

void	print (raw_ostream &OS, unsigned Indent=0) const

LLVM_DUMP_METHOD void	dump () const

bool	matchSimpleRecurrence (const PHINode *P)
	Wraps llvm::matchSimpleRecurrence.

bool	matchConditionalRecurrence (const PHINode *P, Instruction::BinaryOps BOWithConstOpToMatch=Instruction::BinaryOpsEnd)
	A Conditional Recurrence is a recurrence of the form:

Public Attributes
const Loop &	L

const PHINode *	Phi = nullptr

BinaryOperator *	BO = nullptr

Value *	Start = nullptr

Value *	Step = nullptr

std::optional< APInt >	ExtraConst

Detailed Description

A structure that can hold either a Simple Recurrence or a Conditional Recurrence.

Note that in the case of a Simple Recurrence, Step is an operand of the BO, while in a Conditional Recurrence, it is a SelectInst.

Definition at line 277 of file HashRecognize.cpp.

Constructor & Destructor Documentation

◆ RecurrenceInfo()

RecurrenceInfo::RecurrenceInfo ( const Loop & L )

inline

Definition at line 285 of file HashRecognize.cpp.

Member Function Documentation

◆ dump()

LLVM_DUMP_METHOD void RecurrenceInfo::dump ( ) const

inline

Definition at line 309 of file HashRecognize.cpp.

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

◆ matchConditionalRecurrence()

bool RecurrenceInfo::matchConditionalRecurrence	(	const PHINode *	P,
		Instruction::BinaryOps	BOWithConstOpToMatch = `Instruction::BinaryOpsEnd`
	)

A Conditional Recurrence is a recurrence of the form:

loop: rec = phi [start, entry], [step, loop] ... step = select _, tv, fv

where tv and fv ultimately end up using rec via the same BO instruction, after digging through the use-def chain.

ExtraConst is relevant if BOWithConstOpToMatch is supplied: when digging the use-def chain, a BinOp with opcode BOWithConstOpToMatch is matched, and ExtraConst is a constant operand of that BinOp. This peculiarity exists, because in a CRC algorithm, the BOWithConstOpToMatch is an XOR, and the ExtraConst ends up being the generating polynomial.

Definition at line 395 of file HashRecognize.cpp.

References BO, llvm::dbgs(), ExtraConst, llvm::PHINode::getIncomingValue(), llvm::PHINode::getNumIncomingValues(), Idx, LLVM_DEBUG, llvm::PatternMatch::m_Cmp(), llvm::PatternMatch::m_Instruction(), llvm::PatternMatch::m_Select(), llvm::SCEVPatternMatch::match(), P, Phi, Start, and Step.