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author | Kevin Lim <ktlim@umich.edu> | 2005-01-11 19:00:16 -0500 |
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committer | Kevin Lim <ktlim@umich.edu> | 2005-01-11 19:00:16 -0500 |
commit | 42f3b4ffb3fedcb70e9ff068ed7160dc6020b8c4 (patch) | |
tree | ba3d10f448bec63df45dff3bb7f2d6fbd6dcf9c7 /cpu/beta_cpu/decode.hh | |
parent | 202758eea20c092bb85d1886898c3816f377d288 (diff) | |
parent | 90d4436351620bd3861013333aabd152d5492df7 (diff) | |
download | gem5-42f3b4ffb3fedcb70e9ff068ed7160dc6020b8c4.tar.xz |
Merge changes.
base/traceflags.py:
Merge extra new CPU flags
cpu/static_inst.hh:
Include all the execute functions in static_inst_impl.hh
--HG--
extra : convert_revision : 78eb753bf709d37400e7c2418bb35d842d7c3f63
Diffstat (limited to 'cpu/beta_cpu/decode.hh')
-rw-r--r-- | cpu/beta_cpu/decode.hh | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/cpu/beta_cpu/decode.hh b/cpu/beta_cpu/decode.hh new file mode 100644 index 000000000..64e87290e --- /dev/null +++ b/cpu/beta_cpu/decode.hh @@ -0,0 +1,144 @@ +// Todo: +// Add a couple of the branch fields to DynInst. Figure out where DynInst +// should try to compute the target of a PC-relative branch. Try to avoid +// having so many returns within the code. +// Fix up squashing too, as it's too +// dependent upon the iew stage continually telling it to squash. + +#ifndef __SIMPLE_DECODE_HH__ +#define __SIMPLE_DECODE_HH__ + +#include <queue> + +#include "base/timebuf.hh" + +template<class Impl> +class SimpleDecode +{ + private: + // Typedefs from the Impl. + typedef typename Impl::ISA ISA; + typedef typename Impl::FullCPU FullCPU; + typedef typename Impl::DynInstPtr DynInstPtr; + typedef typename Impl::Params Params; + typedef typename Impl::CPUPol CPUPol; + + // Typedefs from the CPU policy. + typedef typename CPUPol::FetchStruct FetchStruct; + typedef typename CPUPol::DecodeStruct DecodeStruct; + typedef typename CPUPol::TimeStruct TimeStruct; + + // Typedefs from the ISA. + typedef typename ISA::Addr Addr; + + public: + // The only time decode will become blocked is if dispatch becomes + // blocked, which means IQ or ROB is probably full. + enum Status { + Running, + Idle, + Squashing, + Blocked, + Unblocking + }; + + private: + // May eventually need statuses on a per thread basis. + Status _status; + + public: + SimpleDecode(Params ¶ms); + + void regStats(); + + void setCPU(FullCPU *cpu_ptr); + + void setTimeBuffer(TimeBuffer<TimeStruct> *tb_ptr); + + void setDecodeQueue(TimeBuffer<DecodeStruct> *dq_ptr); + + void setFetchQueue(TimeBuffer<FetchStruct> *fq_ptr); + + void tick(); + + void decode(); + + // Might want to make squash a friend function. + void squash(); + + private: + void block(); + + inline void unblock(); + + void squash(DynInstPtr &inst); + + // Interfaces to objects outside of decode. + /** CPU interface. */ + FullCPU *cpu; + + /** Time buffer interface. */ + TimeBuffer<TimeStruct> *timeBuffer; + + /** Wire to get rename's output from backwards time buffer. */ + typename TimeBuffer<TimeStruct>::wire fromRename; + + /** Wire to get iew's information from backwards time buffer. */ + typename TimeBuffer<TimeStruct>::wire fromIEW; + + /** Wire to get commit's information from backwards time buffer. */ + typename TimeBuffer<TimeStruct>::wire fromCommit; + + /** Wire to write information heading to previous stages. */ + // Might not be the best name as not only fetch will read it. + typename TimeBuffer<TimeStruct>::wire toFetch; + + /** Decode instruction queue. */ + TimeBuffer<DecodeStruct> *decodeQueue; + + /** Wire used to write any information heading to rename. */ + typename TimeBuffer<DecodeStruct>::wire toRename; + + /** Fetch instruction queue interface. */ + TimeBuffer<FetchStruct> *fetchQueue; + + /** Wire to get fetch's output from fetch queue. */ + typename TimeBuffer<FetchStruct>::wire fromFetch; + + /** Skid buffer between fetch and decode. */ + std::queue<FetchStruct> skidBuffer; + + private: + //Consider making these unsigned to avoid any confusion. + /** Rename to decode delay, in ticks. */ + unsigned renameToDecodeDelay; + + /** IEW to decode delay, in ticks. */ + unsigned iewToDecodeDelay; + + /** Commit to decode delay, in ticks. */ + unsigned commitToDecodeDelay; + + /** Fetch to decode delay, in ticks. */ + unsigned fetchToDecodeDelay; + + /** The width of decode, in instructions. */ + unsigned decodeWidth; + + /** The instruction that decode is currently on. It needs to have + * persistent state so that when a stall occurs in the middle of a + * group of instructions, it can restart at the proper instruction. + */ + unsigned numInst; + + Stats::Scalar<> decodeIdleCycles; + Stats::Scalar<> decodeBlockedCycles; + Stats::Scalar<> decodeUnblockCycles; + Stats::Scalar<> decodeSquashCycles; + Stats::Scalar<> decodeBranchMispred; + Stats::Scalar<> decodeControlMispred; + Stats::Scalar<> decodeDecodedInsts; + Stats::Scalar<> decodeSquashedInsts; +}; + +#endif // __SIMPLE_DECODE_HH__ |