A pattern that compares masked values against dictionary entries. More...

#include <dictionary_compressor.hh>

Inheritance diagram for gem5::compression::DictionaryCompressor< T >::MaskedPattern< mask >:

Public Member Functions
	MaskedPattern (const int number, const uint64_t code, const uint64_t metadata_length, const int match_location, const DictionaryEntry bytes, const bool allocate=true)

DictionaryEntry	decompress (const DictionaryEntry dict_bytes) const override
	Decompress the pattern.

Public Member Functions inherited from gem5::compression::DictionaryCompressor< T >::Pattern
	Pattern (const int number, const uint64_t code, const uint64_t metadata_length, const uint64_t num_unmatched_bits, const int match_location, const bool allocate=true)
	Default constructor.

virtual	~Pattern ()=default
	Default destructor.

int	getPatternNumber () const
	Get enum number associated to this pattern.

uint8_t	getCode () const
	Get code of this pattern.

uint8_t	getMatchLocation () const
	Get the index of the dictionary match location.

virtual std::size_t	getSizeBits () const
	Get size, in bits, of the pattern (excluding prefix).

bool	shouldAllocate () const
	Determine if pattern allocates a dictionary entry.

std::string	print () const
	Extract pattern's information to a string.

Static Public Member Functions
static bool	isPattern (const DictionaryEntry &bytes, const DictionaryEntry &dict_bytes, const int match_location)

Private Attributes
const T	bits
	A copy of the bits that do not belong to the mask.

Additional Inherited Members
Protected Attributes inherited from gem5::compression::DictionaryCompressor< T >::Pattern
const int	patternNumber
	Pattern enum number.

const uint8_t	code
	Code associated to the pattern.

const uint8_t	length
	Length, in bits, of the code and match location.

const uint8_t	numUnmatchedBits
	Number of unmatched bits.

const int	matchLocation
	Index representing the the match location.

const bool	allocate
	Wether the pattern allocates a dictionary entry or not.

Detailed Description

template<class T>
template<T mask>
class gem5::compression::DictionaryCompressor< T >::MaskedPattern< mask >

A pattern that compares masked values against dictionary entries.

If the masked dictionary entry matches perfectly the masked value to be compressed, there is a pattern match.

For example, if the mask is 0xFF00 (that is, this pattern matches the MSB), the value (V) 0xFF20 is being compressed, and the dictionary contains the value (D) 0xFF03, this is a match (V & mask == 0xFF00 == D & mask), and 0x0020 is added to the list of unmatched bits.

Template Parameters

mask	A mask containing the bits that must match.

Definition at line 463 of file dictionary_compressor.hh.

Constructor & Destructor Documentation

◆ MaskedPattern()

template<class T >

template<T mask>

gem5::compression::DictionaryCompressor< T >::MaskedPattern< mask >::MaskedPattern	(	const int	number,
		const uint64_t	code,
		const uint64_t	metadata_length,
		const int	match_location,
		const DictionaryEntry	bytes,
		const bool	allocate = true )

inline

Definition at line 474 of file dictionary_compressor.hh.

Member Function Documentation

◆ decompress()

template<class T >

template<T mask>

DictionaryEntry gem5::compression::DictionaryCompressor< T >::MaskedPattern< mask >::decompress ( const DictionaryEntry dict_bytes ) const

inlineoverridevirtual

Decompress the pattern.

Each pattern has its own way of interpreting its data.

Parameters

dict_bytes The bytes in the corresponding matching entry.

Returns: The decompressed pattern.

Implements gem5::compression::DictionaryCompressor< T >::Pattern.

Reimplemented in gem5::compression::DictionaryCompressor< T >::MaskedValuePattern< value, mask >, and gem5::compression::DictionaryCompressor< T >::MaskedValuePattern< 0, 0xFFFFFFFFFFFFFFFF >.

Definition at line 498 of file dictionary_compressor.hh.

References gem5::bits(), gem5::compression::DictionaryCompressor< T >::fromDictionaryEntry(), gem5::ArmISA::mask, and gem5::compression::DictionaryCompressor< T >::toDictionaryEntry().

Referenced by gem5::compression::DictionaryCompressor< T >::MaskedValuePattern< value, mask >::decompress().

◆ isPattern()

template<class T >

template<T mask>

static bool gem5::compression::DictionaryCompressor< T >::MaskedPattern< mask >::isPattern	(	const DictionaryEntry &	bytes,
		const DictionaryEntry &	dict_bytes,
		const int	match_location )