Base cache compressor interface. More...

#include <base.hh>

Inheritance diagram for BaseCacheCompressor:

Classes
struct	BaseCacheCompressorStats

class	CompressionData

Public Types
typedef BaseCacheCompressorParams	Params
	Convenience typedef. More...

Public Types inherited from SimObject
typedef SimObjectParams	Params

Public Member Functions
	BaseCacheCompressor (const Params *p)
	Default constructor. More...

virtual	~BaseCacheCompressor ()
	Default destructor. More...

void	compress (const uint64_t *data, Cycles &comp_lat, Cycles &decomp_lat, std::size_t &comp_size_bits)
	Apply the compression process to the cache line. More...

Cycles	getDecompressionLatency (const CacheBlk *blk)
	Get the decompression latency if the block is compressed. More...

Public Member Functions inherited from SimObject
const Params *	params () const

	SimObject (const Params *_params)

virtual	~SimObject ()

virtual const std::string	name () const

virtual void	init ()
	init() is called after all C++ SimObjects have been created and all ports are connected. More...

virtual void	loadState (CheckpointIn &cp)
	loadState() is called on each SimObject when restoring from a checkpoint. More...

virtual void	initState ()
	initState() is called on each SimObject when not restoring from a checkpoint. More...

virtual void	regProbePoints ()
	Register probe points for this object. More...

virtual void	regProbeListeners ()
	Register probe listeners for this object. More...

ProbeManager *	getProbeManager ()
	Get the probe manager for this object. More...

virtual Port &	getPort (const std::string &if_name, PortID idx=InvalidPortID)
	Get a port with a given name and index. More...

virtual void	startup ()
	startup() is the final initialization call before simulation. More...

DrainState	drain () override
	Provide a default implementation of the drain interface for objects that don't need draining. More...

virtual void	memWriteback ()
	Write back dirty buffers to memory using functional writes. More...

virtual void	memInvalidate ()
	Invalidate the contents of memory buffers. More...

void	serialize (CheckpointOut &cp) const override
	Serialize an object. More...

void	unserialize (CheckpointIn &cp) override
	Unserialize an object. More...

Public Member Functions inherited from EventManager
	EventManager (EventManager &em)

	EventManager (EventManager *em)

	EventManager (EventQueue *eq)

EventQueue *	eventQueue () const

void	schedule (Event &event, Tick when)

void	deschedule (Event &event)

void	reschedule (Event &event, Tick when, bool always=false)

void	schedule (Event *event, Tick when)

void	deschedule (Event *event)

void	reschedule (Event *event, Tick when, bool always=false)

void	wakeupEventQueue (Tick when=(Tick) -1)

void	setCurTick (Tick newVal)

Public Member Functions inherited from Serializable
	Serializable ()

virtual	~Serializable ()

void	serializeSection (CheckpointOut &cp, const char *name) const
	Serialize an object into a new section. More...

void	serializeSection (CheckpointOut &cp, const std::string &name) const

void	unserializeSection (CheckpointIn &cp, const char *name)
	Unserialize an a child object. More...

void	unserializeSection (CheckpointIn &cp, const std::string &name)

Public Member Functions inherited from Drainable
DrainState	drainState () const
	Return the current drain state of an object. More...

virtual void	notifyFork ()
	Notify a child process of a fork. More...

Public Member Functions inherited from Stats::Group
	Group ()=delete

	Group (const Group &)=delete

Group &	operator= (const Group &)=delete

	Group (Group parent, const char name=nullptr)
	Construct a new statistics group. More...

virtual	~Group ()

virtual void	regStats ()
	Callback to set stat parameters. More...

virtual void	resetStats ()
	Callback to reset stats. More...

virtual void	preDumpStats ()
	Callback before stats are dumped. More...

void	addStat (Stats::Info *info)
	Register a stat with this group. More...

const std::map< std::string, Group * > &	getStatGroups () const
	Get all child groups associated with this object. More...

const std::vector< Info * > &	getStats () const
	Get all stats associated with this object. More...

void	addStatGroup (const char name, Group block)
	Add a stat block as a child of this block. More...

Static Public Member Functions
static void	setDecompressionLatency (CacheBlk *blk, const Cycles lat)
	Set the decompression latency of compressed block. More...

static void	setSizeBits (CacheBlk *blk, const std::size_t size_bits)
	Set the size of the compressed block, in bits. More...

Static Public Member Functions inherited from SimObject
static void	serializeAll (CheckpointOut &cp)
	Serialize all SimObjects in the system. More...

static SimObject *	find (const char *name)
	Find the SimObject with the given name and return a pointer to it. More...

Static Public Member Functions inherited from Serializable
static const std::string &	currentSection ()
	Get the fully-qualified name of the active section. More...

static void	serializeAll (const std::string &cpt_dir)

static void	unserializeGlobals (CheckpointIn &cp)

Protected Member Functions
virtual std::unique_ptr< CompressionData >	compress (const uint64_t *cache_line, Cycles &comp_lat, Cycles &decomp_lat)=0
	Apply the compression process to the cache line. More...

virtual void	decompress (const CompressionData comp_data, uint64_t cache_line)=0
	Apply the decompression process to the compressed data. More...

Protected Member Functions inherited from Drainable
	Drainable ()

virtual	~Drainable ()

virtual void	drainResume ()
	Resume execution after a successful drain. More...

void	signalDrainDone () const
	Signal that an object is drained. More...

Protected Attributes
const std::size_t	blkSize
	Uncompressed cache line size (in bytes). More...

const std::size_t	sizeThreshold
	Size in bytes at which a compression is classified as bad and therefore the compressed block is restored to its uncompressed format. More...

BaseCacheCompressor::BaseCacheCompressorStats	stats

Protected Attributes inherited from SimObject
const SimObjectParams *	_params
	Cached copy of the object parameters. More...

Protected Attributes inherited from EventManager
EventQueue *	eventq
	A pointer to this object's event queue. More...

Friends
class	MultiCompressor
	This compressor must be able to access the protected functions of its sub-compressors. More...

Additional Inherited Members
Static Public Attributes inherited from Serializable
static int	ckptCount = 0

static int	ckptMaxCount = 0

static int	ckptPrevCount = -1

Detailed Description

Base cache compressor interface.

Every cache compressor must implement a compression and a decompression method.

Definition at line 54 of file base.hh.

Member Typedef Documentation

◆ Params

typedef BaseCacheCompressorParams BaseCacheCompressor::Params

Convenience typedef.

Definition at line 130 of file base.hh.

Constructor & Destructor Documentation

◆ BaseCacheCompressor()

BaseCacheCompressor::BaseCacheCompressor ( const Params * p )

Default constructor.

Definition at line 76 of file base.cc.

References blkSize, fatal_if, and sizeThreshold.

◆ ~BaseCacheCompressor()

virtual BaseCacheCompressor::~BaseCacheCompressor ( )

inlinevirtual

Default destructor.

Definition at line 140 of file base.hh.

References compress(), data, getDecompressionLatency(), setDecompressionLatency(), and setSizeBits().

Member Function Documentation

◆ compress() [1/2]

virtual std::unique_ptr<CompressionData> BaseCacheCompressor::compress	(	const uint64_t *	cache_line,
		Cycles &	comp_lat,
		Cycles &	decomp_lat
	)

protectedpure virtual

Apply the compression process to the cache line.

Returns the number of cycles used by the compressor, however it is usually covered by a good pipelined execution, and is currently ignored. The decompression latency is also returned, in order to avoid increasing simulation time and memory consumption.

Parameters

cache_line	The cache line to be compressed.
comp_lat	Compression latency in number of cycles.
decomp_lat	Decompression latency in number of cycles.

Returns: Cache line after compression.

Implemented in FPCD, BaseDelta< BaseType, DeltaSizeBits >, BaseDelta< uint64_t, 32 >, BaseDelta< uint32_t, 16 >, BaseDelta< uint32_t, 8 >, BaseDelta< uint64_t, 8 >, BaseDelta< uint16_t, 8 >, BaseDelta< uint64_t, 16 >, CPack, RepeatedQwordsCompressor, ZeroCompressor, MultiCompressor, and PerfectCompressor.

Referenced by BaseCache::allocateBlock(), compress(), BaseCache::updateCompressionData(), and ~BaseCacheCompressor().

◆ compress() [2/2]

void BaseCacheCompressor::compress	(	const uint64_t *	data,
		Cycles &	comp_lat,
		Cycles &	decomp_lat,
		std::size_t &	comp_size_bits
	)

Apply the compression process to the cache line.

Ignores compression cycles.

Parameters

data	The cache line to be compressed.
comp_lat	Compression latency in number of cycles.
decomp_lat	Decompression latency in number of cycles.
comp_size_bits	Compressed data size (in bits).

Definition at line 84 of file base.cc.

References blkSize, compress(), BaseCacheCompressor::BaseCacheCompressorStats::compressions, BaseCacheCompressor::BaseCacheCompressorStats::compressionSize, BaseCacheCompressor::BaseCacheCompressorStats::compressionSizeBits, decompress(), DPRINTF, fatal_if, sizeThreshold, and stats.

◆ decompress()

virtual void BaseCacheCompressor::decompress	(	const CompressionData *	comp_data,
		uint64_t *	cache_line
	)

protectedpure virtual

Apply the decompression process to the compressed data.

Parameters

comp_data	Compressed cache line.
cache_line	The cache line to be decompressed.

Implemented in DictionaryCompressor< T >, DictionaryCompressor< uint32_t >, DictionaryCompressor< uint16_t >, DictionaryCompressor< BaseType >, DictionaryCompressor< uint64_t >, MultiCompressor, and PerfectCompressor.

Referenced by compress(), and DictionaryCompressor< T >::Pattern::print().

◆ getDecompressionLatency()

Cycles BaseCacheCompressor::getDecompressionLatency ( const CacheBlk * blk )

Get the decompression latency if the block is compressed.

Latency is 0 otherwise.

Parameters

blk	The compressed block.

Definition at line 123 of file base.cc.

References BaseCacheCompressor::BaseCacheCompressorStats::decompressions, DPRINTF, CompressionBlk::getDecompressionLatency(), CompressionBlk::isCompressed(), CompressionBlk::print(), and stats.

Referenced by BaseCache::access(), Cache::handleSnoop(), BaseCache::writebackBlk(), BaseCache::writecleanBlk(), and ~BaseCacheCompressor().

◆ setDecompressionLatency()

void BaseCacheCompressor::setDecompressionLatency	(	CacheBlk *	blk,
		const Cycles	lat
	)

static

Set the decompression latency of compressed block.

Parameters

blk	The compressed block.
lat	The decompression latency.

Definition at line 141 of file base.cc.

Referenced by BaseCache::allocateBlock(), and ~BaseCacheCompressor().

◆ setSizeBits()

void BaseCacheCompressor::setSizeBits	(	CacheBlk *	blk,
		const std::size_t	size_bits
	)

static

Set the size of the compressed block, in bits.

Parameters

blk	The compressed block.
size_bits	The block size.

Definition at line 151 of file base.cc.

Referenced by DictionaryCompressor< T >::CompData::addEntry(), BaseCache::allocateBlock(), BaseDelta< uint64_t, 16 >::compress(), and ~BaseCacheCompressor().

Friends And Related Function Documentation

◆ MultiCompressor

friend class MultiCompressor

friend

This compressor must be able to access the protected functions of its sub-compressors.

Definition at line 61 of file base.hh.

Member Data Documentation

◆ blkSize

const std::size_t BaseCacheCompressor::blkSize

protected

Uncompressed cache line size (in bytes).

Definition at line 67 of file base.hh.

Referenced by BaseCacheCompressor(), PerfectCompressor::compress(), MultiCompressor::compress(), RepeatedQwordsCompressor::compress(), ZeroCompressor::compress(), CPack::compress(), FPCD::compress(), compress(), DictionaryCompressor< uint64_t >::compress(), PerfectCompressor::decompress(), DictionaryCompressor< uint64_t >::decompress(), and BaseCacheCompressor::BaseCacheCompressorStats::regStats().

◆ sizeThreshold

const std::size_t BaseCacheCompressor::sizeThreshold

protected

Size in bytes at which a compression is classified as bad and therefore the compressed block is restored to its uncompressed format.

Definition at line 78 of file base.hh.

Referenced by BaseCacheCompressor(), and compress().

◆ stats

BaseCacheCompressor::BaseCacheCompressorStats BaseCacheCompressor::stats

protected

Referenced by compress(), and getDecompressionLatency().

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

mem/cache/compressors/base.hh
mem/cache/compressors/base.cc

Classes

Public Types

Public Member Functions

Static Public Member Functions

Protected Member Functions

Protected Attributes

Friends

Additional Inherited Members

Detailed Description

Member Typedef Documentation

◆ Params

Constructor & Destructor Documentation

◆ BaseCacheCompressor()

◆ ~BaseCacheCompressor()

Member Function Documentation

◆ compress() [1/2]

◆ compress() [2/2]

◆ decompress()

◆ getDecompressionLatency()

◆ setDecompressionLatency()

◆ setSizeBits()

Friends And Related Function Documentation

◆ MultiCompressor

Member Data Documentation

◆ blkSize

◆ sizeThreshold

◆ stats