gem5  v22.1.0.0
Classes | Public Types | Public Member Functions | Protected Attributes | List of all members
gem5::compression::Multi Class Reference

#include <multi.hh>

Inheritance diagram for gem5::compression::Multi:
gem5::compression::Base gem5::SimObject gem5::EventManager gem5::Serializable gem5::Drainable gem5::statistics::Group gem5::Named

Classes

class  MultiCompData
 
struct  MultiStats
 

Public Types

typedef MultiCompressorParams Params
 
- Public Types inherited from gem5::compression::Base
typedef BaseCacheCompressorParams Params
 
- Public Types inherited from gem5::SimObject
typedef SimObjectParams Params
 

Public Member Functions

 Multi (const Params &p)
 
 ~Multi ()
 
void setCache (BaseCache *_cache) override
 The cache can only be set once. More...
 
std::unique_ptr< Base::CompressionDatacompress (const std::vector< Base::Chunk > &chunks, Cycles &comp_lat, Cycles &decomp_lat) override
 Apply the compression process to the cache line. More...
 
void decompress (const CompressionData *comp_data, uint64_t *data) override
 Apply the decompression process to the compressed data. More...
 
- Public Member Functions inherited from gem5::compression::Base
 Base (const Params &p)
 
virtual ~Base ()=default
 
std::unique_ptr< CompressionDatacompress (const uint64_t *data, Cycles &comp_lat, Cycles &decomp_lat)
 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 gem5::SimObject
const Paramsparams () const
 
 SimObject (const Params &p)
 
virtual ~SimObject ()
 
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...
 
ProbeManagergetProbeManager ()
 Get the probe manager for this object. More...
 
virtual PortgetPort (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 gem5::EventManager
EventQueueeventQueue () 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)
 This function is not needed by the usual gem5 event loop but may be necessary in derived EventQueues which host gem5 on other schedulers. More...
 
void setCurTick (Tick newVal)
 
 EventManager (EventManager &em)
 Event manger manages events in the event queue. More...
 
 EventManager (EventManager *em)
 
 EventManager (EventQueue *eq)
 
- Public Member Functions inherited from gem5::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 gem5::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 gem5::statistics::Group
 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 (statistics::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...
 
const InforesolveStat (std::string name) const
 Resolve a stat by its name within this group. More...
 
void mergeStatGroup (Group *block)
 Merge the contents (stats & children) of a block to this block. More...
 
 Group ()=delete
 
 Group (const Group &)=delete
 
Groupoperator= (const Group &)=delete
 
- Public Member Functions inherited from gem5::Named
 Named (const std::string &name_)
 
virtual ~Named ()=default
 
virtual std::string name () const
 

Protected Attributes

std::vector< Base * > compressors
 List of sub-compressors. More...
 
const std::size_t numEncodingBits
 An encoding is associated to each sub-compressor to inform which sub-compressor to use when decompressing data. More...
 
const Cycles extraDecompressionLatency
 Extra decompression latency to be added to the sub-compressor's decompression latency. More...
 
gem5::compression::Multi::MultiStats multiStats
 
- Protected Attributes inherited from gem5::compression::Base
const std::size_t blkSize
 Uncompressed cache line size (in bytes). More...
 
const unsigned chunkSizeBits
 Chunk size, in number of bits. 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...
 
const Cycles compChunksPerCycle
 Degree of parallelization of the compression process. More...
 
const Cycles compExtraLatency
 Extra latency added to compression due to packaging, shifting or other operations. More...
 
const Cycles decompChunksPerCycle
 Degree of parallelization of the decompression process. More...
 
const Cycles decompExtraLatency
 Extra latency added to decompression due to packaging, shifting or other operations. More...
 
BaseCachecache
 Pointer to the parent cache. More...
 
gem5::compression::Base::BaseStats stats
 
- Protected Attributes inherited from gem5::SimObject
const SimObjectParams & _params
 Cached copy of the object parameters. More...
 
- Protected Attributes inherited from gem5::EventManager
EventQueueeventq
 A pointer to this object's event queue. More...
 

Additional Inherited Members

- Static Public Member Functions inherited from gem5::compression::Base
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 gem5::SimObject
static void serializeAll (const std::string &cpt_dir)
 Create a checkpoint by serializing all SimObjects in the system. More...
 
static SimObjectfind (const char *name)
 Find the SimObject with the given name and return a pointer to it. More...
 
static void setSimObjectResolver (SimObjectResolver *resolver)
 There is a single object name resolver, and it is only set when simulation is restoring from checkpoints. More...
 
static SimObjectResolvergetSimObjectResolver ()
 There is a single object name resolver, and it is only set when simulation is restoring from checkpoints. More...
 
- Static Public Member Functions inherited from gem5::Serializable
static const std::string & currentSection ()
 Gets the fully-qualified name of the active section. More...
 
static void generateCheckpointOut (const std::string &cpt_dir, std::ofstream &outstream)
 Generate a checkpoint file so that the serialization can be routed to it. More...
 
- Protected Types inherited from gem5::compression::Base
typedef uint64_t Chunk
 A chunk is a basic lexical unit. More...
 
- Protected Member Functions inherited from gem5::compression::Base
std::vector< ChunktoChunks (const uint64_t *data) const
 This function splits the raw data into chunks, so that it can be parsed by the compressor. More...
 
void fromChunks (const std::vector< Chunk > &chunks, uint64_t *data) const
 This function re-joins the chunks to recreate the original data. More...
 
- Protected Member Functions inherited from gem5::Drainable
 Drainable ()
 
virtual ~Drainable ()
 
virtual void drainResume ()
 Resume execution after a successful drain. More...
 
void signalDrainDone () const
 Signal that an object is drained. More...
 

Detailed Description

Definition at line 53 of file multi.hh.

Member Typedef Documentation

◆ Params

typedef MultiCompressorParams gem5::compression::Multi::Params

Definition at line 105 of file multi.hh.

Constructor & Destructor Documentation

◆ Multi()

gem5::compression::Multi::Multi ( const Params p)

Definition at line 65 of file multi.cc.

References compressors, and fatal_if.

◆ ~Multi()

gem5::compression::Multi::~Multi ( )

Definition at line 74 of file multi.cc.

References compressors.

Member Function Documentation

◆ compress()

std::unique_ptr< Base::CompressionData > gem5::compression::Multi::compress ( const std::vector< Base::Chunk > &  chunks,
Cycles comp_lat,
Cycles decomp_lat 
)
overridevirtual

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
chunksThe cache line to be compressed, divided into chunks.
comp_latCompression latency in number of cycles.
decomp_latDecompression latency in number of cycles.
Returns
Cache line after compression.

Implements gem5::compression::Base.

Definition at line 91 of file multi.cc.

References gem5::alignToPowerOfTwo(), gem5::compression::Base::blkSize, gem5::compression::Base::compExtraLatency, compressors, data, gem5::compression::Base::decompExtraLatency, DPRINTF, gem5::compression::Base::fromChunks(), gem5::ArmISA::i, gem5::MipsISA::index, multiStats, numEncodingBits, and gem5::compression::Multi::MultiStats::ranks.

◆ decompress()

void gem5::compression::Multi::decompress ( const CompressionData comp_data,
uint64_t *  cache_line 
)
overridevirtual

Apply the decompression process to the compressed data.

Parameters
comp_dataCompressed cache line.
cache_lineThe cache line to be decompressed.

Implements gem5::compression::Base.

Definition at line 185 of file multi.cc.

References gem5::compression::Multi::MultiCompData::compData, compressors, and gem5::compression::Multi::MultiCompData::getIndex().

◆ setCache()

void gem5::compression::Multi::setCache ( BaseCache _cache)
overridevirtual

The cache can only be set once.

Reimplemented from gem5::compression::Base.

Definition at line 82 of file multi.cc.

References compressors, and gem5::compression::Base::setCache().

Member Data Documentation

◆ compressors

std::vector<Base*> gem5::compression::Multi::compressors
protected

List of sub-compressors.

Definition at line 64 of file multi.hh.

Referenced by compress(), decompress(), Multi(), setCache(), and ~Multi().

◆ extraDecompressionLatency

const Cycles gem5::compression::Multi::extraDecompressionLatency
protected

Extra decompression latency to be added to the sub-compressor's decompression latency.

This can different from zero due to decoding, shifting, or packaging, for example.

Definition at line 88 of file multi.hh.

◆ multiStats

gem5::compression::Multi::MultiStats gem5::compression::Multi::multiStats
protected

Referenced by compress().

◆ numEncodingBits

const std::size_t gem5::compression::Multi::numEncodingBits
protected

An encoding is associated to each sub-compressor to inform which sub-compressor to use when decompressing data.

This information can be added either to the tag entry, in which case no extra bits are added to the compressed data (numEncodingBits = 0), or to the compressed data itself.

There is no encoding reserved for the uncompressed case; it is assumed that an "is compressed" bit is stored in the tags. Therefore, even if storing the encoding within the compressed data, these extra bits are not added when the data is uncompressible.

These extra bits are taken into account when thresholding the compressed data's size.

Definition at line 81 of file multi.hh.

Referenced by compress().


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

Generated on Wed Dec 21 2022 10:23:40 for gem5 by doxygen 1.9.1