#include <decoder.hh>

Inheritance diagram for gem5::ArmISA::Decoder:

Public Member Functions
	Decoder (const ArmDecoderParams &params)

void	reset () override
	Reset the decoders internal state.

void	moreBytes (const PCStateBase &pc, Addr fetchPC) override
	Feed data to the decoder.

StaticInstPtr	decode (PCStateBase &pc) override
	Decode an instruction or fetch it from the code cache.

void	setContext (FPSCR fpscr)

void	setSveLen (uint8_t len)

void	setSmeLen (uint8_t len)

Public Member Functions inherited from gem5::InstDecoder
template<typename MoreBytesType >
	InstDecoder (const InstDecoderParams &params, MoreBytesType *mb_buf)

virtual StaticInstPtr	fetchRomMicroop (MicroPC micropc, StaticInstPtr curMacroop)

template<class Type >
Type &	as ()

template<class Type >
const Type &	as () const

virtual void	takeOverFrom (InstDecoder *old)
	Take over the state from an old decoder when switching CPUs.

void *	moreBytesPtr () const

size_t	moreBytesSize () const

Addr	pcMask () const

bool	instReady () const
	Is an instruction ready to be decoded?

bool	needMoreBytes () const
	Can the decoder accept more data?

Public Member Functions inherited from gem5::SimObject
const Params &	params () 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.

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

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

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

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

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

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

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

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

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

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

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

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

Public Member Functions inherited from gem5::EventManager
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)
	This function is not needed by the usual gem5 event loop but may be necessary in derived EventQueues which host gem5 on other schedulers.

void	setCurTick (Tick newVal)

	EventManager (EventManager &em)
	Event manger manages events in the event queue.

	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.

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

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

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.

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

Public Member Functions inherited from gem5::statistics::Group
	Group (Group parent, const char name=nullptr)
	Construct a new statistics group.

virtual	~Group ()

virtual void	regStats ()
	Callback to set stat parameters.

virtual void	resetStats ()
	Callback to reset stats.

virtual void	preDumpStats ()
	Callback before stats are dumped.

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

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

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

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

const Info *	resolveStat (std::string name) const
	Resolve a stat by its name within this group.

void	mergeStatGroup (Group *block)
	Merge the contents (stats & children) of a block to this block.

	Group ()=delete

	Group (const Group &)=delete

Group &	operator= (const Group &)=delete

Public Member Functions inherited from gem5::Named
	Named (const std::string &name_)

virtual	~Named ()=default

virtual std::string	name () const

Public Attributes
const bool	dvmEnabled
	True if the decoder should emit DVM Ops (treated as Loads)

Protected Member Functions
void	process ()
	Pre-decode an instruction from the current state of the decoder.

void	consumeBytes (int numBytes)
	Consume bytes by moving the offset into the data word and sanity check the results.

StaticInstPtr	decodeInst (ExtMachInst mach_inst)
	Decode a machine instruction without calling the cache.

StaticInstPtr	decode (ExtMachInst mach_inst, Addr addr)
	Decode a pre-decoded machine instruction.

Protected Member Functions inherited from gem5::Drainable
	Drainable ()

virtual	~Drainable ()

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

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

Protected Attributes
ExtMachInst	emi

uint32_t	data

bool	bigThumb

int	offset

bool	foundIt

ITSTATE	itBits

int	fpscrLen

int	fpscrStride

int	sveLen
	SVE vector length, encoded in the same format as the ZCR_EL<x>.LEN bitfields.

int	smeLen
	SME vector length, encoded in the same format as the SMCR_EL<x>.LEN bitfields.

enums::DecoderFlavor	decoderFlavor

Protected Attributes inherited from gem5::InstDecoder
void *	_moreBytesPtr

size_t	_moreBytesSize

Addr	_pcMask

bool	instDone = false

bool	outOfBytes = true

Protected Attributes inherited from gem5::SimObject
const SimObjectParams &	_params
	Cached copy of the object parameters.

Protected Attributes inherited from gem5::EventManager
EventQueue *	eventq
	A pointer to this object's event queue.

Static Protected Attributes
static GenericISA::BasicDecodeCache< Decoder, ExtMachInst >	defaultCache
	A cache of decoded instruction objects.

Friends
class	GenericISA::BasicDecodeCache< Decoder, ExtMachInst >

Additional Inherited Members
Public Types inherited from gem5::SimObject
typedef SimObjectParams	Params

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.

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

static void	setSimObjectResolver (SimObjectResolver *resolver)
	There is a single object name resolver, and it is only set when simulation is restoring from checkpoints.

static SimObjectResolver *	getSimObjectResolver ()
	There is a single object name resolver, and it is only set when simulation is restoring from checkpoints.

Static Public Member Functions inherited from gem5::Serializable
static const std::string &	currentSection ()
	Gets the fully-qualified name of the active section.

static void	generateCheckpointOut (const std::string &cpt_dir, std::ofstream &outstream)
	Generate a checkpoint file so that the serialization can be routed to it.

Detailed Description

Definition at line 64 of file decoder.hh.

Constructor & Destructor Documentation

◆ Decoder()

gem5::ArmISA::Decoder::Decoder ( const ArmDecoderParams & params )

Definition at line 58 of file decoder.cc.

References dvmEnabled, gem5::SimObject::params(), reset(), gem5::safe_cast(), smeLen, sveLen, and warn_once.

Member Function Documentation

◆ consumeBytes()

void gem5::ArmISA::Decoder::consumeBytes ( int numBytes )

protected

Consume bytes by moving the offset into the data word and sanity check the results.

Definition at line 160 of file decoder.cc.

References data, emi, offset, and gem5::InstDecoder::outOfBytes.

Referenced by process().

◆ decode() [1/2]

StaticInstPtr gem5::ArmISA::Decoder::decode	(	ExtMachInst	mach_inst,
		Addr	addr )

inlineprotected

Decode a pre-decoded machine instruction.

@warn This method takes a pre-decoded instruction as its argument. It should typically not be called directly.

Parameters

mach_inst A pre-decoded instruction

Return values

A	pointer to the corresponding StaticInst object.

Definition at line 136 of file decoder.hh.

References gem5::X86ISA::addr, defaultCache, DPRINTF, emi, and gem5::ArmISA::si.

Referenced by decode().

◆ decode() [2/2]

StaticInstPtr gem5::ArmISA::Decoder::decode ( PCStateBase & pc )

overridevirtual

Decode an instruction or fetch it from the code cache.

This method decodes the currently pending pre-decoded instruction. Data must be fed to the decoder using moreBytes() until instReady() is true before calling this method.

Parameters

pc	Instruction pointer that we are decoding.

Returns: A pointer to a static instruction or NULL if the decoder isn't ready (see instReady()).

Implements gem5::InstDecoder.

Definition at line 189 of file decoder.cc.

References gem5::PCStateBase::as(), decode(), emi, foundIt, gem5::InstDecoder::instDone, itBits, and gem5::MipsISA::pc.

◆ decodeInst()

StaticInstPtr gem5::ArmISA::Decoder::decodeInst ( ExtMachInst mach_inst )

protected

Decode a machine instruction without calling the cache.

Note: The implementation of this method is generated by the ISA parser script.

@warn This method takes a pre-decoded instruction as its argument. It should typically not be called directly.

Parameters

mach_inst The binary instruction to decode.

Return values

A	pointer to the corresponding StaticInst object.

◆ moreBytes()

void gem5::ArmISA::Decoder::moreBytes	(	const PCStateBase &	pc,
		Addr	fetchPC )

overridevirtual

Feed data to the decoder.

A CPU model uses this interface to load instruction data into the decoder. Once enough data has been loaded (check with instReady()), a decoded instruction can be retrieved using decode(PCStateBase &).

This method is intended to support both fixed-length and variable-length instructions. Instruction data is fetch in MachInst blocks (which correspond to the size of a typical insturction). The method might need to be called multiple times if the instruction spans multiple blocks, in that case needMoreBytes() will return true and instReady() will return false.

The fetchPC parameter is used to indicate where in memory the instruction was fetched from. This is should be the same address as the pc. If fetching multiple blocks, it indicates where subsequent blocks are fetched from (pc + n * sizeof(MachInst)).

Parameters

pc	Instruction pointer that we are decoding.
fetchPC	The address this chunk was fetched from.

Implements gem5::InstDecoder.

Definition at line 169 of file decoder.cc.

References gem5::PCStateBase::as(), data, emi, fpscrLen, fpscrStride, gem5::letoh(), offset, gem5::ArmISA::OK, gem5::InstDecoder::outOfBytes, gem5::MipsISA::pc, process(), sveLen, and gem5::ArmISA::UNALIGNED.

◆ process()

void gem5::ArmISA::Decoder::process ( )

protected

Pre-decode an instruction from the current state of the decoder.

Definition at line 93 of file decoder.cc.

References bigThumb, gem5::bits(), gem5::ArmISA::COND_UC, consumeBytes(), data, DPRINTF, emi, foundIt, gem5::InstDecoder::instDone, itBits, and offset.

Referenced by moreBytes().

◆ reset()

void gem5::ArmISA::Decoder::reset ( )

overridevirtual

Reset the decoders internal state.

Reimplemented from gem5::InstDecoder.

Definition at line 83 of file decoder.cc.

References bigThumb, emi, foundIt, offset, and gem5::InstDecoder::reset().

Referenced by Decoder().

◆ setContext()

void gem5::ArmISA::Decoder::setContext ( FPSCR fpscr )

inline

Definition at line 157 of file decoder.hh.

References fpscrLen, and fpscrStride.

◆ setSmeLen()

void gem5::ArmISA::Decoder::setSmeLen ( uint8_t len )

inline

Definition at line 170 of file decoder.hh.

References gem5::ArmISA::len, and smeLen.

◆ setSveLen()

void gem5::ArmISA::Decoder::setSveLen ( uint8_t len )

inline

Definition at line 164 of file decoder.hh.

References gem5::ArmISA::len, and sveLen.

Friends And Related Symbol Documentation

◆ GenericISA::BasicDecodeCache< Decoder, ExtMachInst >

friend class GenericISA::BasicDecodeCache< Decoder, ExtMachInst >

friend

Definition at line 97 of file decoder.hh.

Member Data Documentation

◆ bigThumb

bool gem5::ArmISA::Decoder::bigThumb

protected

Definition at line 74 of file decoder.hh.

Referenced by process(), and reset().

◆ data

uint32_t gem5::ArmISA::Decoder::data

protected

Definition at line 73 of file decoder.hh.

Referenced by consumeBytes(), moreBytes(), and process().

◆ decoderFlavor

enums::DecoderFlavor gem5::ArmISA::Decoder::decoderFlavor

protected

Definition at line 94 of file decoder.hh.

◆ defaultCache

GenericISA::BasicDecodeCache< Decoder, ExtMachInst > gem5::ArmISA::Decoder::defaultCache

staticprotected

A cache of decoded instruction objects.

Definition at line 97 of file decoder.hh.

Referenced by decode().

◆ dvmEnabled

const bool gem5::ArmISA::Decoder::dvmEnabled

True if the decoder should emit DVM Ops (treated as Loads)

Definition at line 68 of file decoder.hh.

Referenced by Decoder().

◆ emi

ExtMachInst gem5::ArmISA::Decoder::emi

protected

Definition at line 72 of file decoder.hh.

Referenced by consumeBytes(), decode(), decode(), moreBytes(), process(), and reset().

◆ foundIt

bool gem5::ArmISA::Decoder::foundIt

protected

Definition at line 76 of file decoder.hh.

Referenced by decode(), process(), and reset().

◆ fpscrLen

int gem5::ArmISA::Decoder::fpscrLen

protected

Definition at line 79 of file decoder.hh.

Referenced by moreBytes(), and setContext().

◆ fpscrStride

int gem5::ArmISA::Decoder::fpscrStride

protected

Definition at line 80 of file decoder.hh.

Referenced by moreBytes(), and setContext().

◆ itBits

ITSTATE gem5::ArmISA::Decoder::itBits

protected

Definition at line 77 of file decoder.hh.

Referenced by decode(), and process().

◆ offset

int gem5::ArmISA::Decoder::offset

protected

Definition at line 75 of file decoder.hh.

Referenced by consumeBytes(), moreBytes(), process(), and reset().

◆ smeLen

int gem5::ArmISA::Decoder::smeLen

protected

SME vector length, encoded in the same format as the SMCR_EL<x>.LEN bitfields.

Definition at line 92 of file decoder.hh.

Referenced by Decoder(), and setSmeLen().

◆ sveLen

int gem5::ArmISA::Decoder::sveLen

protected

SVE vector length, encoded in the same format as the ZCR_EL<x>.LEN bitfields.

Definition at line 86 of file decoder.hh.

Referenced by Decoder(), moreBytes(), and setSveLen().

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

arch/arm/decoder.hh
arch/arm/decoder.cc

Public Member Functions

Public Attributes

Protected Member Functions

Protected Attributes

Static Protected Attributes

Friends

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ Decoder()

Member Function Documentation

◆ consumeBytes()

◆ decode() [1/2]

◆ decode() [2/2]

◆ decodeInst()

◆ moreBytes()

◆ process()

◆ reset()

◆ setContext()

◆ setSmeLen()

◆ setSveLen()

Friends And Related Symbol Documentation

◆ GenericISA::BasicDecodeCache< Decoder, ExtMachInst >

Member Data Documentation

◆ bigThumb

◆ data

◆ decoderFlavor

◆ defaultCache

◆ dvmEnabled

◆ emi

◆ foundIt

◆ fpscrLen

◆ fpscrStride

◆ itBits

◆ offset

◆ smeLen

◆ sveLen