diff options
Diffstat (limited to 'cpu/beta_cpu/decode_impl.hh')
-rw-r--r-- | cpu/beta_cpu/decode_impl.hh | 56 |
1 files changed, 31 insertions, 25 deletions
diff --git a/cpu/beta_cpu/decode_impl.hh b/cpu/beta_cpu/decode_impl.hh index 9d88f94ac..43a4e8e95 100644 --- a/cpu/beta_cpu/decode_impl.hh +++ b/cpu/beta_cpu/decode_impl.hh @@ -99,6 +99,13 @@ SimpleDecode<Impl>::setFetchQueue(TimeBuffer<FetchStruct> *fq_ptr) } template<class Impl> +inline bool +SimpleDecode<Impl>::fetchInstsValid() +{ + return fromFetch->size > 0; +} + +template<class Impl> void SimpleDecode<Impl>::block() { @@ -156,14 +163,14 @@ SimpleDecode<Impl>::squash(DynInstPtr &inst) // Set status to squashing. _status = Squashing; - // Maybe advance the time buffer? Not sure what to do in the normal - // case. - // Clear the skid buffer in case it has any data in it. - while (!skidBuffer.empty()) - { + while (!skidBuffer.empty()) { skidBuffer.pop(); } + + // Squash instructions up until this one + // Slightly unrealistic! + cpu->removeInstsUntil(inst->seqNum); } template<class Impl> @@ -205,7 +212,7 @@ SimpleDecode<Impl>::tick() if (_status == Unblocking) { ++decodeUnblockCycles; - if (fromFetch->size > 0) { + if (fetchInstsValid()) { // Add the current inputs to the skid buffer so they can be // reprocessed when this stage unblocks. skidBuffer.push(*fromFetch); @@ -216,7 +223,7 @@ SimpleDecode<Impl>::tick() } else if (_status == Blocked) { ++decodeBlockedCycles; - if (fromFetch->size > 0) { + if (fetchInstsValid()) { block(); } @@ -240,12 +247,12 @@ SimpleDecode<Impl>::tick() squash(); } } else if (_status == Squashing) { - ++decodeSquashCycles; - if (!fromCommit->commitInfo.squash && !fromCommit->commitInfo.robSquashing) { _status = Running; } else if (fromCommit->commitInfo.squash) { + ++decodeSquashCycles; + squash(); } } @@ -264,8 +271,7 @@ SimpleDecode<Impl>::decode() // Check time buffer if being told to stall. if (fromRename->renameInfo.stall || fromIEW->iewInfo.stall || - fromCommit->commitInfo.stall) - { + fromCommit->commitInfo.stall) { block(); return; } @@ -273,7 +279,7 @@ SimpleDecode<Impl>::decode() // Check fetch queue to see if instructions are available. // If no available instructions, do nothing, unless this stage is // currently unblocking. - if (fromFetch->size == 0 && _status != Unblocking) { + if (!fetchInstsValid() && _status != Unblocking) { DPRINTF(Decode, "Decode: Nothing to do, breaking out early.\n"); // Should I change the status to idle? ++decodeIdleCycles; @@ -286,7 +292,7 @@ SimpleDecode<Impl>::decode() unsigned to_rename_index = 0; int insts_available = _status == Unblocking ? - skidBuffer.front().size : + skidBuffer.front().size - numInst : fromFetch->size; // Debug block... @@ -308,8 +314,8 @@ SimpleDecode<Impl>::decode() } #endif - while (insts_available > 0) - { + while (insts_available > 0) + { DPRINTF(Decode, "Decode: Sending instruction to rename.\n"); inst = _status == Unblocking ? skidBuffer.front().insts[numInst] : @@ -331,6 +337,16 @@ SimpleDecode<Impl>::decode() continue; } + + // Also check if instructions have no source registers. Mark + // them as ready to issue at any time. Not sure if this check + // should exist here or at a later stage; however it doesn't matter + // too much for function correctness. + // Isn't this handled by the inst queue? + if (inst->numSrcRegs() == 0) { + inst->setCanIssue(); + } + // This current instruction is valid, so add it into the decode // queue. The next instruction may not be valid, so check to // see if branches were predicted correctly. @@ -369,16 +385,6 @@ SimpleDecode<Impl>::decode() // addr (either the immediate, or the branch PC + 4) and redirect // fetch if it's incorrect. - - // Also check if instructions have no source registers. Mark - // them as ready to issue at any time. Not sure if this check - // should exist here or at a later stage; however it doesn't matter - // too much for function correctness. - // Isn't this handled by the inst queue? - if (inst->numSrcRegs() == 0) { - inst->setCanIssue(); - } - // Increment which instruction we're looking at. ++numInst; ++to_rename_index; |