A basic compression superblock. More...

#include <super_blk.hh>

Inheritance diagram for gem5::SuperBlk:

Public Member Functions
	SuperBlk ()

	SuperBlk (const SuperBlk &)=delete

SuperBlk &	operator= (const SuperBlk &)=delete

	~SuperBlk ()

bool	isCompressed (const CompressionBlk *ignored_blk=nullptr) const
	Returns whether the superblock contains compressed blocks or not.

bool	canCoAllocate (const std::size_t compressed_size) const
	Checks whether a superblock can co-allocate given compressed data block.

void	setBlkSize (const std::size_t blk_size)
	Set block size.

uint8_t	calculateCompressionFactor (const std::size_t size) const
	Calculate the compression factor (cf) given a compressed size and the maximum compression ratio.

uint8_t	getCompressionFactor () const
	Get the compression factor of this superblock.

void	setCompressionFactor (const uint8_t compression_factor)
	Set the compression factor of this superblock.

void	invalidate () override
	Invalidate the block.

std::string	print () const override
	Print relevant information for this sector block and its sub-blocks.

Public Member Functions inherited from gem5::SectorBlk
	SectorBlk ()

	SectorBlk (const SectorBlk &)=delete

SectorBlk &	operator= (const SectorBlk &)=delete

	~SectorBlk ()

bool	isValid () const override
	Checks that a sector block is valid.

uint8_t	getNumValid () const
	Get the number of sub-blocks that have been validated.

void	validateSubBlk ()
	Increase the number of valid sub-blocks.

void	invalidateSubBlk ()
	Decrease the number of valid sub-blocks.

void	setPosition (const uint32_t set, const uint32_t way) override
	Sets the position of the sub-entries, besides its own.

Public Member Functions inherited from gem5::TaggedEntry
	TaggedEntry ()

	~TaggedEntry ()=default

bool	isSecure () const
	Check if this block holds data from the secure memory space.

virtual bool	matchTag (Addr tag, bool is_secure) const
	Checks if the given tag information corresponds to this entry's.

virtual void	insert (const Addr tag, const bool is_secure)
	Insert the block by assigning it a tag and marking it valid.

void	invalidate () override
	Invalidate the block.

std::string	print () const override
	Prints relevant information about this entry.

bool	matchTag (const Addr tag) const override
	Checks if the given tag information corresponds to this entry's.

void	insert (const Addr tag) override
	Insert the block by assigning it a tag and marking it valid.

Public Member Functions inherited from gem5::CacheEntry
	CacheEntry ()=default

	~CacheEntry ()=default

virtual Addr	getTag () const
	Get tag associated to this block.

Public Member Functions inherited from gem5::ReplaceableEntry
	ReplaceableEntry ()

virtual	~ReplaceableEntry ()=default

uint32_t	getSet () const
	Get set number.

uint32_t	getWay () const
	Get way number.

Protected Attributes
std::size_t	blkSize
	Block size, in bytes.

uint8_t	compressionFactor
	Superblock's compression factor.

Protected Attributes inherited from gem5::ReplaceableEntry
uint32_t	_set
	Set to which this entry belongs.

uint32_t	_way
	Way (relative position within the set) to which this entry belongs.

Additional Inherited Members
Public Attributes inherited from gem5::SectorBlk
std::vector< SectorSubBlk * >	blks
	List of blocks associated to this sector.

Public Attributes inherited from gem5::ReplaceableEntry
std::shared_ptr< replacement_policy::ReplacementData >	replacementData
	Replacement data associated to this entry.

Protected Member Functions inherited from gem5::TaggedEntry
virtual void	setSecure ()
	Set secure bit.

Protected Member Functions inherited from gem5::CacheEntry
virtual void	setTag (Addr _tag)
	Set tag associated to this block.

virtual void	setValid ()
	Set valid bit.

Detailed Description

A basic compression superblock.

Contains the tag and a list of blocks associated to this superblock.

Definition at line 170 of file super_blk.hh.

Constructor & Destructor Documentation

◆ SuperBlk() [1/2]

gem5::SuperBlk::SuperBlk ( )

Definition at line 171 of file super_blk.cc.

◆ SuperBlk() [2/2]

gem5::SuperBlk::SuperBlk ( const SuperBlk & )

delete

◆ ~SuperBlk()

gem5::SuperBlk::~SuperBlk ( )

inline

Definition at line 187 of file super_blk.hh.

Member Function Documentation

◆ calculateCompressionFactor()

uint8_t gem5::SuperBlk::calculateCompressionFactor ( const std::size_t size ) const

Calculate the compression factor (cf) given a compressed size and the maximum compression ratio.

Therefore cf is: 1 if comp_size > blk_size/2, 2 if comp_size > blk_size/4, 4 if comp_size > blk_size/8, 8 if comp_size > blk_size/16, and so on.

Parameters

size	The compressed size.

Returns: Compression factor corresponding to the size.

Definition at line 214 of file super_blk.cc.

References gem5::alignToPowerOfTwo(), gem5::SectorBlk::blks, and blkSize.

Referenced by gem5::CompressionBlk::checkExpansionContraction(), and gem5::CompressionBlk::setSizeBits().

◆ canCoAllocate()

bool gem5::SuperBlk::canCoAllocate ( const std::size_t compressed_size ) const

Checks whether a superblock can co-allocate given compressed data block.

Parameters

compressed_size Size, in bits, of new block to allocate.

Returns: True if block can be co-allocated in superblock.

Definition at line 197 of file super_blk.cc.

References blkSize, getCompressionFactor(), and gem5::SectorBlk::getNumValid().

Referenced by gem5::CompressedTags::findVictim().

◆ getCompressionFactor()

uint8_t gem5::SuperBlk::getCompressionFactor ( ) const

Get the compression factor of this superblock.

Returns: The compression factor.

Definition at line 227 of file super_blk.cc.

References compressionFactor.

Referenced by canCoAllocate(), gem5::CompressionBlk::checkExpansionContraction(), and print().

◆ invalidate()

void gem5::SuperBlk::invalidate ( )

overridevirtual

Invalidate the block.

Its contents are no longer valid.

Reimplemented from gem5::CacheEntry.

Definition at line 177 of file super_blk.cc.

References compressionFactor, and gem5::CacheEntry::invalidate().

◆ isCompressed()

bool gem5::SuperBlk::isCompressed ( const CompressionBlk * ignored_blk = nullptr ) const

Returns whether the superblock contains compressed blocks or not.

By default, if not blocks are valid, the superblock is compressible.

Parameters

ignored_blk If provided don't consider the given block.

Returns: The compressibility state of the superblock.

Definition at line 184 of file super_blk.cc.

References gem5::SectorBlk::blks, and isCompressed().

Referenced by gem5::CompressedTags::findVictim(), isCompressed(), and gem5::CompressionBlk::setSizeBits().

◆ operator=()

SuperBlk & gem5::SuperBlk::operator= ( const SuperBlk & )

delete

◆ print()

std::string gem5::SuperBlk::print ( ) const

overridevirtual

Print relevant information for this sector block and its sub-blocks.

Returns: A string with the contents of the sector block.

Reimplemented from gem5::SectorBlk.

Definition at line 244 of file super_blk.cc.

References gem5::csprintf(), getCompressionFactor(), and gem5::SectorBlk::print().

Referenced by gem5::CompressedTags::findVictim().

◆ setBlkSize()

void gem5::SuperBlk::setBlkSize ( const std::size_t blk_size )

Set block size.

Should be called only once, when initializing blocks.

Parameters

blk_size The uncompressed block size.

Definition at line 207 of file super_blk.cc.

References blkSize.

Referenced by gem5::CompressedTags::tagsInit().

◆ setCompressionFactor()

void gem5::SuperBlk::setCompressionFactor ( const uint8_t compression_factor )

Set the compression factor of this superblock.

Parameters

compression_factor The new compression factor.

Definition at line 233 of file super_blk.cc.

References compressionFactor, and gem5::SectorBlk::getNumValid().

Referenced by gem5::CompressionBlk::setSizeBits().

Member Data Documentation

◆ blkSize

std::size_t gem5::SuperBlk::blkSize

protected

Block size, in bytes.

Definition at line 174 of file super_blk.hh.

Referenced by calculateCompressionFactor(), canCoAllocate(), and setBlkSize().

◆ compressionFactor

uint8_t gem5::SuperBlk::compressionFactor

protected

Superblock's compression factor.

It is aligned to be a power of two, limited by the maximum compression ratio, and calculated as: compressionFactor = uncompressedSize/compressedSize

Definition at line 181 of file super_blk.hh.

Referenced by getCompressionFactor(), invalidate(), and setCompressionFactor().

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

mem/cache/tags/super_blk.hh
mem/cache/tags/super_blk.cc

Public Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ SuperBlk() [1/2]

◆ SuperBlk() [2/2]

◆ ~SuperBlk()

Member Function Documentation

◆ calculateCompressionFactor()

◆ canCoAllocate()

◆ getCompressionFactor()

◆ invalidate()

◆ isCompressed()

◆ operator=()

◆ print()

◆ setBlkSize()

◆ setCompressionFactor()

Member Data Documentation

◆ blkSize

◆ compressionFactor