The analysis. More...

#include "llvm/Analysis/HashRecognize.h"

Public Member Functions
	HashRecognize (const Loop &L, ScalarEvolution &SE)

std::variant< PolynomialInfo, ErrBits, StringRef >	recognizeCRC () const
	The main entry point for analyzing a loop and recognizing the CRC algorithm.

std::optional< PolynomialInfo >	getResult () const

void	print (raw_ostream &OS) const

LLVM_DUMP_METHOD void	dump () const

Static Public Member Functions
static CRCTable	genSarwateTable (const APInt &GenPoly, bool ByteOrderSwapped)
	Generate a lookup table of 256 entries by interleaving the generating polynomial.

Detailed Description

The analysis.

Definition at line 80 of file HashRecognize.h.

Constructor & Destructor Documentation

◆ HashRecognize()

HashRecognize::HashRecognize	(	const Loop &	L,
		ScalarEvolution &	SE
	)

Definition at line 739 of file HashRecognize.cpp.

Member Function Documentation

◆ dump()

void HashRecognize::dump ( ) const

Definition at line 729 of file HashRecognize.cpp.

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

◆ genSarwateTable()

CRCTable HashRecognize::genSarwateTable	(	const APInt &	GenPoly,
		bool	ByteOrderSwapped
	)

static

Generate a lookup table of 256 entries by interleaving the generating polynomial.

The optimization technique of table-lookup for CRC is also called the Sarwate algorithm.

Definition at line 485 of file HashRecognize.cpp.

References llvm::APInt::getBitWidth(), llvm::APInt::getSignedMinValue(), llvm::APInt::getZero(), I, llvm::APInt::isSignBitSet(), llvm::APInt::lshr(), and llvm::APInt::shl().

Referenced by print().

◆ getResult()

std::optional< PolynomialInfo > HashRecognize::getResult ( ) const

Definition at line 732 of file HashRecognize.cpp.

References recognizeCRC().

◆ print()

void HashRecognize::print ( raw_ostream & OS ) const

Definition at line 685 of file HashRecognize.cpp.

References genSarwateTable(), llvm::raw_ostream::indent(), Info, OS, llvm::CRCTable::print(), and recognizeCRC().

Referenced by dump(), and llvm::HashRecognizePrinterPass::run().

◆ recognizeCRC()

std::variant< PolynomialInfo, ErrBits, StringRef > HashRecognize::recognizeCRC ( ) const

The main entry point for analyzing a loop and recognizing the CRC algorithm.

Returns a PolynomialInfo on success, and either an ErrBits or a StringRef on failure.

Definition at line 576 of file HashRecognize.cpp.

References assert(), llvm::DenseMapBase< DerivedT, KeyT, ValueT, KeyInfoT, BucketT >::at(), llvm::BasicBlock::begin(), checkExtractBits(), ValueEvolution::computeEvolutions(), llvm::SmallVectorImpl< T >::emplace_back(), llvm::BasicBlock::end(), llvm::KnownBits::getBitWidth(), ValueEvolution::getError(), llvm::PHINode::getIncomingValueForBlock(), llvm::Type::getIntegerBitWidth(), getRecurrences(), llvm::ScalarEvolution::getSmallConstantTripCount(), llvm::BasicBlock::getTerminator(), llvm::Value::getType(), llvm::SmallPtrSetImpl< PtrType >::insert_range(), isBigEndianBitShift(), isConditionalOnXorOfPHIs(), ValueEvolution::KnownPhis, LHS, N, llvm::none_of(), llvm::SmallPtrSetImplBase::size(), and ValueEvolution::Visited.

Referenced by getResult(), and print().

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

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

Public Member Functions

Static Public Member Functions