This stage receives lines of data from Fetch1, separates them into instructions and passes them to Decode. More...
#include <fetch2.hh>
Classes | |
| struct | Fetch2Stats |
| struct | Fetch2ThreadInfo |
| Data members after this line are cycle-to-cycle state. More... | |
Public Member Functions | |
| Fetch2 (const std::string &name, MinorCPU &cpu_, const BaseMinorCPUParams ¶ms, Latch< ForwardLineData >::Output inp_, Latch< BranchData >::Output branchInp_, Latch< BranchData >::Input predictionOut_, Latch< ForwardInstData >::Input out_, std::vector< InputBuffer< ForwardInstData >> &next_stage_input_buffer) | |
| void | evaluate () |
| Pass on input/buffer data to the output if you can. More... | |
| void | minorTrace () const |
| bool | isDrained () |
| Is this stage drained? For Fetch2, draining is initiated by Execute halting Fetch1 causing Fetch2 to naturally drain. More... | |
 Public Member Functions inherited from gem5::Named | |
| Named (const std::string &name_) | |
| virtual | ~Named ()=default |
| virtual std::string | name () const |
Public Attributes | |
| std::vector< InputBuffer< ForwardLineData > > | inputBuffer |
Protected Member Functions | |
| const ForwardLineData * | getInput (ThreadID tid) |
| Get a piece of data to work on from the inputBuffer, or 0 if there is no data. More... | |
| void | popInput (ThreadID tid) |
| Pop an element off the input buffer, if there are any. More... | |
| void | dumpAllInput (ThreadID tid) |
| Dump the whole contents of the input buffer. More... | |
| void | updateBranchPrediction (const BranchData &branch) |
| Update local branch prediction structures from feedback from Execute. More... | |
| void | predictBranch (MinorDynInstPtr inst, BranchData &branch) |
| Predicts branches for the given instruction. More... | |
| ThreadID | getScheduledThread () |
| Use the current threading policy to determine the next thread to fetch from. More... | |
Protected Attributes | |
| MinorCPU & | cpu |
| Pointer back to the containing CPU. More... | |
| Latch< ForwardLineData >::Output | inp |
| Input port carrying lines from Fetch1. More... | |
| Latch< BranchData >::Output | branchInp |
| Input port carrying branches from Execute. More... | |
| Latch< BranchData >::Input | predictionOut |
| Output port carrying predictions back to Fetch1. More... | |
| Latch< ForwardInstData >::Input | out |
| Output port carrying instructions into Decode. More... | |
| std::vector< InputBuffer< ForwardInstData > > & | nextStageReserve |
| Interface to reserve space in the next stage. More... | |
| unsigned int | outputWidth |
| Width of output of this stage/input of next in instructions. More... | |
| bool | processMoreThanOneInput |
| If true, more than one input word can be processed each cycle if there is room in the output to contain its processed data. More... | |
| branch_prediction::BPredUnit & | branchPredictor |
| Branch predictor passed from Python configuration. More... | |
| std::vector< Fetch2ThreadInfo > | fetchInfo |
| ThreadID | threadPriority |
| gem5::minor::Fetch2::Fetch2Stats | stats |
Detailed Description
This stage receives lines of data from Fetch1, separates them into instructions and passes them to Decode.
Constructor & Destructor Documentation
◆ Fetch2()
| gem5::minor::Fetch2::Fetch2 | ( | const std::string & | name, |
| MinorCPU & | cpu_, | ||
| const BaseMinorCPUParams & | params, | ||
| Latch< ForwardLineData >::Output | inp_, | ||
| Latch< BranchData >::Output | branchInp_, | ||
| Latch< BranchData >::Input | predictionOut_, | ||
| Latch< ForwardInstData >::Input | out_, | ||
| std::vector< InputBuffer< ForwardInstData >> & | next_stage_input_buffer | ||
| ) |
Definition at line 59 of file fetch2.cc.
References fatal, inputBuffer, gem5::Named::name(), outputWidth, and sc_dt::to_string().
Member Function Documentation
◆ dumpAllInput()
|
protected |
Dump the whole contents of the input buffer.
Useful after a prediction changes control flow
Definition at line 120 of file fetch2.cc.
References DPRINTF, fetchInfo, inputBuffer, and popInput().
Referenced by evaluate().
◆ evaluate()
| void gem5::minor::Fetch2::evaluate | ( | ) |
Pass on input/buffer data to the output if you can.
Reserve a slot in the next stage and output data
Definition at line 240 of file fetch2.cc.
References gem5::ActivityRecorder::activateStage(), gem5::ActivityRecorder::activity(), gem5::MinorCPU::activityRecorder, gem5::StaticInst::advancePC(), gem5::minor::Fetch2::Fetch2Stats::amoInstructions, gem5::minor::Fetch2::Fetch2ThreadInfo::blocked, branchInp, cpu, decoder, DPRINTF, dumpAllInput(), gem5::minor::Fetch2::Fetch2ThreadInfo::expectedStreamSeqNum, gem5::minor::ForwardLineData::fault, gem5::minor::Pipeline::Fetch2StageId, fetchInfo, gem5::minor::Fetch2::Fetch2ThreadInfo::fetchSeqNum, gem5::minor::Fetch2::Fetch2Stats::fpInstructions, gem5::BaseCPU::getContext(), gem5::ThreadContext::getDecoderPtr(), getInput(), getScheduledThread(), gem5::minor::Fetch2::Fetch2ThreadInfo::havePC, gem5::ArmISA::i, gem5::minor::ForwardLineData::id, inp, inputBuffer, gem5::minor::Fetch2::Fetch2ThreadInfo::inputIndex, gem5::minor::ForwardInstData::insts, gem5::minor::Fetch2::Fetch2Stats::intInstructions, gem5::InvalidThreadID, gem5::StaticInst::isAtomic(), gem5::minor::BranchData::isBubble(), gem5::minor::ForwardInstData::isBubble(), gem5::minor::ForwardLineData::isFault(), gem5::StaticInst::isFloating(), gem5::StaticInst::isInteger(), gem5::StaticInst::isLoad(), gem5::StaticInst::isStore(), gem5::minor::BranchData::isStreamChange(), gem5::StaticInst::isVector(), gem5::minor::Fetch2::Fetch2ThreadInfo::lastStreamSeqNum, gem5::minor::ForwardLineData::line, gem5::minor::ForwardLineData::lineBaseAddr, gem5::minor::ForwardLineData::lineWidth, gem5::minor::Fetch2::Fetch2Stats::loadInstructions, nextStageReserve, gem5::nullStaticInstPtr, gem5::BaseCPU::numThreads, out, outputWidth, gem5::minor::Fetch2::Fetch2ThreadInfo::pc, gem5::minor::ForwardLineData::pc, popInput(), predictBranch(), predictionOut, gem5::minor::InstId::predictionSeqNum, gem5::minor::Fetch2::Fetch2ThreadInfo::predictionSeqNum, processMoreThanOneInput, gem5::minor::ForwardInstData::resize(), gem5::ArmISA::set, stats, gem5::minor::Fetch2::Fetch2Stats::storeInstructions, gem5::minor::InstId::streamSeqNum, gem5::minor::InstId::threadId, gem5::minor::BranchData::threadId, gem5::minor::ForwardInstData::threadId, updateBranchPrediction(), and gem5::minor::Fetch2::Fetch2Stats::vecInstructions.
Referenced by gem5::minor::Pipeline::evaluate().
◆ getInput()
|
protected |
Get a piece of data to work on from the inputBuffer, or 0 if there is no data.
Definition at line 98 of file fetch2.cc.
References inputBuffer.
Referenced by evaluate(), and getScheduledThread().
◆ getScheduledThread()
|
inlineprotected |
Use the current threading policy to determine the next thread to fetch from.
Definition at line 561 of file fetch2.cc.
References cpu, fetchInfo, getInput(), gem5::InvalidThreadID, panic, gem5::auxv::Random, gem5::MinorCPU::randomPriority(), gem5::MinorCPU::roundRobinPriority(), gem5::MinorCPU::threadPolicy, and threadPriority.
Referenced by evaluate().
◆ isDrained()
| bool gem5::minor::Fetch2::isDrained | ( | ) |
Is this stage drained? For Fetch2, draining is initiated by Execute halting Fetch1 causing Fetch2 to naturally drain.
Branch predictions are ignored by Fetch1 during halt
Definition at line 591 of file fetch2.cc.
References inp, inputBuffer, and predictionOut.
Referenced by gem5::minor::Pipeline::isDrained().
◆ minorTrace()
| void gem5::minor::Fetch2::minorTrace | ( | ) | const |
Definition at line 632 of file fetch2.cc.
References data, fetchInfo, inputBuffer, gem5::minor::minorTrace(), and out.
Referenced by gem5::minor::Pipeline::minorTrace().
◆ popInput()
|
protected |
Pop an element off the input buffer, if there are any.
Definition at line 109 of file fetch2.cc.
References fetchInfo, and inputBuffer.
Referenced by dumpAllInput(), and evaluate().
◆ predictBranch()
|
protected |
Predicts branches for the given instruction.
Updates the instruction's predicted... fields and also the branch which carries the prediction to Fetch1
Definition at line 192 of file fetch2.cc.
References gem5::minor::BranchData::BranchPrediction, branchPredictor, DPRINTF, gem5::minor::Fetch2::Fetch2ThreadInfo::expectedStreamSeqNum, fetchInfo, gem5::branch_prediction::BPredUnit::predict(), gem5::minor::Fetch2::Fetch2ThreadInfo::predictionSeqNum, gem5::ArmISA::set, and gem5::minor::BranchData::target.
Referenced by evaluate().
◆ updateBranchPrediction()
|
protected |
Update local branch prediction structures from feedback from Execute.
Definition at line 130 of file fetch2.cc.
References gem5::minor::BranchData::BadlyPredictedBranch, gem5::minor::BranchData::BadlyPredictedBranchTarget, gem5::minor::BranchData::BranchPrediction, branchPredictor, gem5::minor::BranchData::CorrectlyPredictedBranch, DPRINTF, gem5::minor::BranchData::HaltFetch, gem5::minor::BranchData::inst, gem5::minor::BranchData::Interrupt, gem5::minor::BranchData::NoBranch, gem5::minor::BranchData::reason, gem5::branch_prediction::BPredUnit::squash(), gem5::minor::BranchData::SuspendThread, gem5::minor::BranchData::target, gem5::minor::BranchData::UnpredictedBranch, and gem5::branch_prediction::BPredUnit::update().
Referenced by evaluate().
Member Data Documentation
◆ branchInp
|
protected |
Input port carrying branches from Execute.
This is a snoop of the data provided to F1.
Definition at line 77 of file fetch2.hh.
Referenced by evaluate().
◆ branchPredictor
|
protected |
Branch predictor passed from Python configuration.
Definition at line 96 of file fetch2.hh.
Referenced by predictBranch(), and updateBranchPrediction().
◆ cpu
|
protected |
Pointer back to the containing CPU.
Definition at line 70 of file fetch2.hh.
Referenced by evaluate(), and getScheduledThread().
◆ fetchInfo
|
protected |
Definition at line 161 of file fetch2.hh.
Referenced by dumpAllInput(), evaluate(), getScheduledThread(), minorTrace(), popInput(), and predictBranch().
◆ inp
|
protected |
Input port carrying lines from Fetch1.
Definition at line 73 of file fetch2.hh.
Referenced by evaluate(), and isDrained().
◆ inputBuffer
| std::vector<InputBuffer<ForwardLineData> > gem5::minor::Fetch2::inputBuffer |
Definition at line 100 of file fetch2.hh.
Referenced by dumpAllInput(), evaluate(), Fetch2(), getInput(), isDrained(), minorTrace(), and popInput().
◆ nextStageReserve
|
protected |
Interface to reserve space in the next stage.
Definition at line 86 of file fetch2.hh.
Referenced by evaluate().
◆ out
|
protected |
Output port carrying instructions into Decode.
Definition at line 83 of file fetch2.hh.
Referenced by evaluate(), and minorTrace().
◆ outputWidth
|
protected |
Width of output of this stage/input of next in instructions.
Definition at line 89 of file fetch2.hh.
Referenced by evaluate(), and Fetch2().
◆ predictionOut
|
protected |
Output port carrying predictions back to Fetch1.
Definition at line 80 of file fetch2.hh.
Referenced by evaluate(), and isDrained().
◆ processMoreThanOneInput
|
protected |
If true, more than one input word can be processed each cycle if there is room in the output to contain its processed data.
Definition at line 93 of file fetch2.hh.
Referenced by evaluate().
◆ stats
|
protected |
Referenced by evaluate().
◆ threadPriority
|
protected |
Definition at line 162 of file fetch2.hh.
Referenced by getScheduledThread().
The documentation for this class was generated from the following files: