gem5::compression::DictionaryCompressor< T >::SignExtendedPattern< N > Class Template Reference

A pattern that checks whether the value is an N bits sign-extended value, that is, all the MSB starting from the Nth are equal to the (N-1)th bit. More...

#include <dictionary_compressor.hh>

Inheritance diagram for gem5::compression::DictionaryCompressor< T >::SignExtendedPattern< N >:

Public Member Functions
	SignExtendedPattern (const int number, const uint64_t code, const uint64_t metadata_length, const DictionaryEntry bytes, const bool allocate=false)
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: N
	The non-extended original value.

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<unsigned N>
class gem5::compression::DictionaryCompressor< T >::SignExtendedPattern< N >

A pattern that checks whether the value is an N bits sign-extended value, that is, all the MSB starting from the Nth are equal to the (N-1)th bit.

Therefore, if N = 8, and T has 16 bits, the values within the ranges [0x0000, 0x007F] and [0xFF80, 0xFFFF] would match this pattern.

Template Parameters

N	The number of bits in the non-extended original value. It must fit in a dictionary entry.

Definition at line 756 of file dictionary_compressor.hh.

Constructor & Destructor Documentation

SignExtendedPattern()

template<class T >

template<unsigned N>

gem5::compression::DictionaryCompressor< T >::SignExtendedPattern< N >::SignExtendedPattern ( const int number, const uint64_t code, const uint64_t metadata_length, const DictionaryEntry bytes, const bool allocate = false )

inline

Definition at line 767 of file dictionary_compressor.hh.

Member Function Documentation

decompress()

template<class T >

template<unsigned N>

DictionaryEntry gem5::compression::DictionaryCompressor< T >::SignExtendedPattern< N >::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.

Definition at line 787 of file dictionary_compressor.hh.

References gem5::bits(), gem5::sext(), and gem5::compression::DictionaryCompressor< T >::toDictionaryEntry().

isPattern()

template<class T >

template<unsigned N>

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

inlinestatic

Definition at line 779 of file dictionary_compressor.hh.

References data, gem5::compression::DictionaryCompressor< T >::fromDictionaryEntry(), and gem5::szext().

Member Data Documentation

bits

template<class T >

template<unsigned N>

const T gem5::compression::DictionaryCompressor< T >::SignExtendedPattern< N >::bits

private

The non-extended original value.

Definition at line 764 of file dictionary_compressor.hh.

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

• mem/cache/compressors/dictionary_compressor.hh