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Diffstat (limited to 'cpu/beta_cpu/iew.hh')
-rw-r--r-- | cpu/beta_cpu/iew.hh | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/cpu/beta_cpu/iew.hh b/cpu/beta_cpu/iew.hh new file mode 100644 index 000000000..e3e7c6db5 --- /dev/null +++ b/cpu/beta_cpu/iew.hh @@ -0,0 +1,190 @@ +//Todo: Update with statuses. +//Need to handle delaying writes to the writeback bus if it's full at the +//given time. Load store queue. + +#ifndef __CPU_BETA_CPU_SIMPLE_IEW_HH__ +#define __CPU_BETA_CPU_SIMPLE_IEW_HH__ + +#include <queue> + +#include "base/statistics.hh" +#include "base/timebuf.hh" +#include "cpu/beta_cpu/comm.hh" + +//Can IEW even stall? Space should be available/allocated already...maybe +//if there's not enough write ports on the ROB or waiting for CDB +//arbitration. +template<class Impl, class IQ> +class SimpleIEW +{ + private: + //Typedefs from Impl + typedef typename Impl::ISA ISA; + typedef typename Impl::CPUPol CPUPol; + typedef typename Impl::DynInstPtr DynInstPtr; + typedef typename Impl::FullCPU FullCPU; + typedef typename Impl::Params Params; + + typedef typename CPUPol::RenameMap RenameMap; + typedef typename CPUPol::LDSTQ LDSTQ; + + typedef typename CPUPol::TimeStruct TimeStruct; + typedef typename CPUPol::IEWStruct IEWStruct; + typedef typename CPUPol::RenameStruct RenameStruct; + typedef typename CPUPol::IssueStruct IssueStruct; + + public: + enum Status { + Running, + Blocked, + Idle, + Squashing, + Unblocking + }; + + private: + Status _status; + Status _issueStatus; + Status _exeStatus; + Status _wbStatus; + + public: + void squash(); + + void squashDueToBranch(DynInstPtr &inst); + + void squashDueToMem(DynInstPtr &inst); + + void block(); + + inline void unblock(); + + public: + SimpleIEW(Params ¶ms); + + void regStats(); + + void setCPU(FullCPU *cpu_ptr); + + void setTimeBuffer(TimeBuffer<TimeStruct> *tb_ptr); + + void setRenameQueue(TimeBuffer<RenameStruct> *rq_ptr); + + void setIEWQueue(TimeBuffer<IEWStruct> *iq_ptr); + + void setRenameMap(RenameMap *rm_ptr); + + void wakeDependents(DynInstPtr &inst); + + void tick(); + + void iew(); + + private: + void dispatchInsts(); + + void executeInsts(); + + //Interfaces to objects inside and outside of IEW. + /** Time buffer interface. */ + TimeBuffer<TimeStruct> *timeBuffer; + + /** Wire to get commit's output from backwards time buffer. */ + typename TimeBuffer<TimeStruct>::wire fromCommit; + + /** Wire to write information heading to previous stages. */ + typename TimeBuffer<TimeStruct>::wire toRename; + + /** Rename instruction queue interface. */ + TimeBuffer<RenameStruct> *renameQueue; + + /** Wire to get rename's output from rename queue. */ + typename TimeBuffer<RenameStruct>::wire fromRename; + + /** Issue stage queue. */ + TimeBuffer<IssueStruct> issueToExecQueue; + + /** Wire to read information from the issue stage time queue. */ + typename TimeBuffer<IssueStruct>::wire fromIssue; + + /** + * IEW stage time buffer. Holds ROB indices of instructions that + * can be marked as completed. + */ + TimeBuffer<IEWStruct> *iewQueue; + + /** Wire to write infromation heading to commit. */ + typename TimeBuffer<IEWStruct>::wire toCommit; + + //Will need internal queue to hold onto instructions coming from + //the rename stage in case of a stall. + /** Skid buffer between rename and IEW. */ + std::queue<RenameStruct> skidBuffer; + + /** Instruction queue. */ + IQ instQueue; + + LDSTQ ldstQueue; + + /** Pointer to rename map. Might not want this stage to directly + * access this though... + */ + RenameMap *renameMap; + + /** CPU interface. */ + FullCPU *cpu; + + private: + /** Commit to IEW delay, in ticks. */ + unsigned commitToIEWDelay; + + /** Rename to IEW delay, in ticks. */ + unsigned renameToIEWDelay; + + /** + * Issue to execute delay, in ticks. What this actually represents is + * the amount of time it takes for an instruction to wake up, be + * scheduled, and sent to a FU for execution. + */ + unsigned issueToExecuteDelay; + + /** Width of issue's read path, in instructions. The read path is both + * the skid buffer and the rename instruction queue. + * Note to self: is this really different than issueWidth? + */ + unsigned issueReadWidth; + + /** Width of issue, in instructions. */ + unsigned issueWidth; + + /** Width of execute, in instructions. Might make more sense to break + * down into FP vs int. + */ + unsigned executeWidth; + + /** Number of cycles stage has been squashing. Used so that the stage + * knows when it can start unblocking, which is when the previous stage + * has received the stall signal and clears up its outputs. + */ + unsigned cyclesSquashing; + + Stats::Scalar<> iewIdleCycles; + Stats::Scalar<> iewSquashCycles; + Stats::Scalar<> iewBlockCycles; + Stats::Scalar<> iewUnblockCycles; +// Stats::Scalar<> iewWBInsts; + Stats::Scalar<> iewDispatchedInsts; + Stats::Scalar<> iewDispSquashedInsts; + Stats::Scalar<> iewDispLoadInsts; + Stats::Scalar<> iewDispStoreInsts; + Stats::Scalar<> iewDispNonSpecInsts; + Stats::Scalar<> iewIQFullEvents; + Stats::Scalar<> iewExecutedInsts; + Stats::Scalar<> iewExecLoadInsts; + Stats::Scalar<> iewExecStoreInsts; + Stats::Scalar<> iewExecSquashedInsts; + Stats::Scalar<> memOrderViolationEvents; + Stats::Scalar<> predictedTakenIncorrect; +}; + +#endif // __CPU_BETA_CPU_IEW_HH__ |