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Diffstat (limited to 'src/cpu/o3/inst_queue_impl.hh')
| -rw-r--r-- | src/cpu/o3/inst_queue_impl.hh | 1405 |
1 files changed, 1405 insertions, 0 deletions
diff --git a/src/cpu/o3/inst_queue_impl.hh b/src/cpu/o3/inst_queue_impl.hh new file mode 100644 index 000000000..6edb528a9 --- /dev/null +++ b/src/cpu/o3/inst_queue_impl.hh @@ -0,0 +1,1405 @@ +/* + * Copyright (c) 2004-2006 The Regents of The University of Michigan + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer; + * redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution; + * neither the name of the copyright holders nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * Authors: Kevin Lim + * Korey Sewell + */ + +#include <limits> +#include <vector> + +#include "sim/root.hh" + +#include "cpu/o3/fu_pool.hh" +#include "cpu/o3/inst_queue.hh" + +template <class Impl> +InstructionQueue<Impl>::FUCompletion::FUCompletion(DynInstPtr &_inst, + int fu_idx, + InstructionQueue<Impl> *iq_ptr) + : Event(&mainEventQueue, Stat_Event_Pri), + inst(_inst), fuIdx(fu_idx), iqPtr(iq_ptr), freeFU(false) +{ + this->setFlags(Event::AutoDelete); +} + +template <class Impl> +void +InstructionQueue<Impl>::FUCompletion::process() +{ + iqPtr->processFUCompletion(inst, freeFU ? fuIdx : -1); + inst = NULL; +} + + +template <class Impl> +const char * +InstructionQueue<Impl>::FUCompletion::description() +{ + return "Functional unit completion event"; +} + +template <class Impl> +InstructionQueue<Impl>::InstructionQueue(Params *params) + : fuPool(params->fuPool), + numEntries(params->numIQEntries), + totalWidth(params->issueWidth), + numPhysIntRegs(params->numPhysIntRegs), + numPhysFloatRegs(params->numPhysFloatRegs), + commitToIEWDelay(params->commitToIEWDelay) +{ + assert(fuPool); + + switchedOut = false; + + numThreads = params->numberOfThreads; + + // Set the number of physical registers as the number of int + float + numPhysRegs = numPhysIntRegs + numPhysFloatRegs; + + DPRINTF(IQ, "There are %i physical registers.\n", numPhysRegs); + + //Create an entry for each physical register within the + //dependency graph. + dependGraph.resize(numPhysRegs); + + // Resize the register scoreboard. + regScoreboard.resize(numPhysRegs); + + //Initialize Mem Dependence Units + for (int i = 0; i < numThreads; i++) { + memDepUnit[i].init(params,i); + memDepUnit[i].setIQ(this); + } + + resetState(); + + std::string policy = params->smtIQPolicy; + + //Convert string to lowercase + std::transform(policy.begin(), policy.end(), policy.begin(), + (int(*)(int)) tolower); + + //Figure out resource sharing policy + if (policy == "dynamic") { + iqPolicy = Dynamic; + + //Set Max Entries to Total ROB Capacity + for (int i = 0; i < numThreads; i++) { + maxEntries[i] = numEntries; + } + + } else if (policy == "partitioned") { + iqPolicy = Partitioned; + + //@todo:make work if part_amt doesnt divide evenly. + int part_amt = numEntries / numThreads; + + //Divide ROB up evenly + for (int i = 0; i < numThreads; i++) { + maxEntries[i] = part_amt; + } + + DPRINTF(IQ, "IQ sharing policy set to Partitioned:" + "%i entries per thread.\n",part_amt); + + } else if (policy == "threshold") { + iqPolicy = Threshold; + + double threshold = (double)params->smtIQThreshold / 100; + + int thresholdIQ = (int)((double)threshold * numEntries); + + //Divide up by threshold amount + for (int i = 0; i < numThreads; i++) { + maxEntries[i] = thresholdIQ; + } + + DPRINTF(IQ, "IQ sharing policy set to Threshold:" + "%i entries per thread.\n",thresholdIQ); + } else { + assert(0 && "Invalid IQ Sharing Policy.Options Are:{Dynamic," + "Partitioned, Threshold}"); + } +} + +template <class Impl> +InstructionQueue<Impl>::~InstructionQueue() +{ + dependGraph.reset(); +#ifdef DEBUG + cprintf("Nodes traversed: %i, removed: %i\n", + dependGraph.nodesTraversed, dependGraph.nodesRemoved); +#endif +} + +template <class Impl> +std::string +InstructionQueue<Impl>::name() const +{ + return cpu->name() + ".iq"; +} + +template <class Impl> +void +InstructionQueue<Impl>::regStats() +{ + using namespace Stats; + iqInstsAdded + .name(name() + ".iqInstsAdded") + .desc("Number of instructions added to the IQ (excludes non-spec)") + .prereq(iqInstsAdded); + + iqNonSpecInstsAdded + .name(name() + ".iqNonSpecInstsAdded") + .desc("Number of non-speculative instructions added to the IQ") + .prereq(iqNonSpecInstsAdded); + + iqInstsIssued + .name(name() + ".iqInstsIssued") + .desc("Number of instructions issued") + .prereq(iqInstsIssued); + + iqIntInstsIssued + .name(name() + ".iqIntInstsIssued") + .desc("Number of integer instructions issued") + .prereq(iqIntInstsIssued); + + iqFloatInstsIssued + .name(name() + ".iqFloatInstsIssued") + .desc("Number of float instructions issued") + .prereq(iqFloatInstsIssued); + + iqBranchInstsIssued + .name(name() + ".iqBranchInstsIssued") + .desc("Number of branch instructions issued") + .prereq(iqBranchInstsIssued); + + iqMemInstsIssued + .name(name() + ".iqMemInstsIssued") + .desc("Number of memory instructions issued") + .prereq(iqMemInstsIssued); + + iqMiscInstsIssued + .name(name() + ".iqMiscInstsIssued") + .desc("Number of miscellaneous instructions issued") + .prereq(iqMiscInstsIssued); + + iqSquashedInstsIssued + .name(name() + ".iqSquashedInstsIssued") + .desc("Number of squashed instructions issued") + .prereq(iqSquashedInstsIssued); + + iqSquashedInstsExamined + .name(name() + ".iqSquashedInstsExamined") + .desc("Number of squashed instructions iterated over during squash;" + " mainly for profiling") + .prereq(iqSquashedInstsExamined); + + iqSquashedOperandsExamined + .name(name() + ".iqSquashedOperandsExamined") + .desc("Number of squashed operands that are examined and possibly " + "removed from graph") + .prereq(iqSquashedOperandsExamined); + + iqSquashedNonSpecRemoved + .name(name() + ".iqSquashedNonSpecRemoved") + .desc("Number of squashed non-spec instructions that were removed") + .prereq(iqSquashedNonSpecRemoved); +/* + queueResDist + .init(Num_OpClasses, 0, 99, 2) + .name(name() + ".IQ:residence:") + .desc("cycles from dispatch to issue") + .flags(total | pdf | cdf ) + ; + for (int i = 0; i < Num_OpClasses; ++i) { + queueResDist.subname(i, opClassStrings[i]); + } +*/ + numIssuedDist + .init(0,totalWidth,1) + .name(name() + ".ISSUE:issued_per_cycle") + .desc("Number of insts issued each cycle") + .flags(pdf) + ; +/* + dist_unissued + .init(Num_OpClasses+2) + .name(name() + ".ISSUE:unissued_cause") + .desc("Reason ready instruction not issued") + .flags(pdf | dist) + ; + for (int i=0; i < (Num_OpClasses + 2); ++i) { + dist_unissued.subname(i, unissued_names[i]); + } +*/ + statIssuedInstType + .init(numThreads,Num_OpClasses) + .name(name() + ".ISSUE:FU_type") + .desc("Type of FU issued") + .flags(total | pdf | dist) + ; + statIssuedInstType.ysubnames(opClassStrings); + + // + // How long did instructions for a particular FU type wait prior to issue + // +/* + issueDelayDist + .init(Num_OpClasses,0,99,2) + .name(name() + ".ISSUE:") + .desc("cycles from operands ready to issue") + .flags(pdf | cdf) + ; + + for (int i=0; i<Num_OpClasses; ++i) { + std::stringstream subname; + subname << opClassStrings[i] << "_delay"; + issueDelayDist.subname(i, subname.str()); + } +*/ + issueRate + .name(name() + ".ISSUE:rate") + .desc("Inst issue rate") + .flags(total) + ; + issueRate = iqInstsIssued / cpu->numCycles; + + statFuBusy + .init(Num_OpClasses) + .name(name() + ".ISSUE:fu_full") + .desc("attempts to use FU when none available") + .flags(pdf | dist) + ; + for (int i=0; i < Num_OpClasses; ++i) { + statFuBusy.subname(i, opClassStrings[i]); + } + + fuBusy + .init(numThreads) + .name(name() + ".ISSUE:fu_busy_cnt") + .desc("FU busy when requested") + .flags(total) + ; + + fuBusyRate + .name(name() + ".ISSUE:fu_busy_rate") + .desc("FU busy rate (busy events/executed inst)") + .flags(total) + ; + fuBusyRate = fuBusy / iqInstsIssued; + + for ( int i=0; i < numThreads; i++) { + // Tell mem dependence unit to reg stats as well. + memDepUnit[i].regStats(); + } +} + +template <class Impl> +void +InstructionQueue<Impl>::resetState() +{ + //Initialize thread IQ counts + for (int i = 0; i <numThreads; i++) { + count[i] = 0; + instList[i].clear(); + } + + // Initialize the number of free IQ entries. + freeEntries = numEntries; + + // Note that in actuality, the registers corresponding to the logical + // registers start off as ready. However this doesn't matter for the + // IQ as the instruction should have been correctly told if those + // registers are ready in rename. Thus it can all be initialized as + // unready. + for (int i = 0; i < numPhysRegs; ++i) { + regScoreboard[i] = false; + } + + for (int i = 0; i < numThreads; ++i) { + squashedSeqNum[i] = 0; + } + + for (int i = 0; i < Num_OpClasses; ++i) { + while (!readyInsts[i].empty()) + readyInsts[i].pop(); + queueOnList[i] = false; + readyIt[i] = listOrder.end(); + } + nonSpecInsts.clear(); + listOrder.clear(); +} + +template <class Impl> +void +InstructionQueue<Impl>::setActiveThreads(std::list<unsigned> *at_ptr) +{ + DPRINTF(IQ, "Setting active threads list pointer.\n"); + activeThreads = at_ptr; +} + +template <class Impl> +void +InstructionQueue<Impl>::setIssueToExecuteQueue(TimeBuffer<IssueStruct> *i2e_ptr) +{ + DPRINTF(IQ, "Set the issue to execute queue.\n"); + issueToExecuteQueue = i2e_ptr; +} + +template <class Impl> +void +InstructionQueue<Impl>::setTimeBuffer(TimeBuffer<TimeStruct> *tb_ptr) +{ + DPRINTF(IQ, "Set the time buffer.\n"); + timeBuffer = tb_ptr; + + fromCommit = timeBuffer->getWire(-commitToIEWDelay); +} + +template <class Impl> +void +InstructionQueue<Impl>::switchOut() +{ +/* + if (!instList[0].empty() || (numEntries != freeEntries) || + !readyInsts[0].empty() || !nonSpecInsts.empty() || !listOrder.empty()) { + dumpInsts(); +// assert(0); + } +*/ + resetState(); + dependGraph.reset(); + instsToExecute.clear(); + switchedOut = true; + for (int i = 0; i < numThreads; ++i) { + memDepUnit[i].switchOut(); + } +} + +template <class Impl> +void +InstructionQueue<Impl>::takeOverFrom() +{ + switchedOut = false; +} + +template <class Impl> +int +InstructionQueue<Impl>::entryAmount(int num_threads) +{ + if (iqPolicy == Partitioned) { + return numEntries / num_threads; + } else { + return 0; + } +} + + +template <class Impl> +void +InstructionQueue<Impl>::resetEntries() +{ + if (iqPolicy != Dynamic || numThreads > 1) { + int active_threads = (*activeThreads).size(); + + std::list<unsigned>::iterator threads = (*activeThreads).begin(); + std::list<unsigned>::iterator list_end = (*activeThreads).end(); + + while (threads != list_end) { + if (iqPolicy == Partitioned) { + maxEntries[*threads++] = numEntries / active_threads; + } else if(iqPolicy == Threshold && active_threads == 1) { + maxEntries[*threads++] = numEntries; + } + } + } +} + +template <class Impl> +unsigned +InstructionQueue<Impl>::numFreeEntries() +{ + return freeEntries; +} + +template <class Impl> +unsigned +InstructionQueue<Impl>::numFreeEntries(unsigned tid) +{ + return maxEntries[tid] - count[tid]; +} + +// Might want to do something more complex if it knows how many instructions +// will be issued this cycle. +template <class Impl> +bool +InstructionQueue<Impl>::isFull() +{ + if (freeEntries == 0) { + return(true); + } else { + return(false); + } +} + +template <class Impl> +bool +InstructionQueue<Impl>::isFull(unsigned tid) +{ + if (numFreeEntries(tid) == 0) { + return(true); + } else { + return(false); + } +} + +template <class Impl> +bool +InstructionQueue<Impl>::hasReadyInsts() +{ + if (!listOrder.empty()) { + return true; + } + + for (int i = 0; i < Num_OpClasses; ++i) { + if (!readyInsts[i].empty()) { + return true; + } + } + + return false; +} + +template <class Impl> +void +InstructionQueue<Impl>::insert(DynInstPtr &new_inst) +{ + // Make sure the instruction is valid + assert(new_inst); + + DPRINTF(IQ, "Adding instruction [sn:%lli] PC %#x to the IQ.\n", + new_inst->seqNum, new_inst->readPC()); + + assert(freeEntries != 0); + + instList[new_inst->threadNumber].push_back(new_inst); + + --freeEntries; + + new_inst->setInIQ(); + + // Look through its source registers (physical regs), and mark any + // dependencies. + addToDependents(new_inst); + + // Have this instruction set itself as the producer of its destination + // register(s). + addToProducers(new_inst); + + if (new_inst->isMemRef()) { + memDepUnit[new_inst->threadNumber].insert(new_inst); + } else { + addIfReady(new_inst); + } + + ++iqInstsAdded; + + count[new_inst->threadNumber]++; + + assert(freeEntries == (numEntries - countInsts())); +} + +template <class Impl> +void +InstructionQueue<Impl>::insertNonSpec(DynInstPtr &new_inst) +{ + // @todo: Clean up this code; can do it by setting inst as unable + // to issue, then calling normal insert on the inst. + + assert(new_inst); + + nonSpecInsts[new_inst->seqNum] = new_inst; + + DPRINTF(IQ, "Adding non-speculative instruction [sn:%lli] PC %#x " + "to the IQ.\n", + new_inst->seqNum, new_inst->readPC()); + + assert(freeEntries != 0); + + instList[new_inst->threadNumber].push_back(new_inst); + + --freeEntries; + + new_inst->setInIQ(); + + // Have this instruction set itself as the producer of its destination + // register(s). + addToProducers(new_inst); + + // If it's a memory instruction, add it to the memory dependency + // unit. + if (new_inst->isMemRef()) { + memDepUnit[new_inst->threadNumber].insertNonSpec(new_inst); + } + + ++iqNonSpecInstsAdded; + + count[new_inst->threadNumber]++; + + assert(freeEntries == (numEntries - countInsts())); +} + +template <class Impl> +void +InstructionQueue<Impl>::insertBarrier(DynInstPtr &barr_inst) +{ + memDepUnit[barr_inst->threadNumber].insertBarrier(barr_inst); + + insertNonSpec(barr_inst); +} + +template <class Impl> +typename Impl::DynInstPtr +InstructionQueue<Impl>::getInstToExecute() +{ + assert(!instsToExecute.empty()); + DynInstPtr inst = instsToExecute.front(); + instsToExecute.pop_front(); + return inst; +} + +template <class Impl> +void +InstructionQueue<Impl>::addToOrderList(OpClass op_class) +{ + assert(!readyInsts[op_class].empty()); + + ListOrderEntry queue_entry; + + queue_entry.queueType = op_class; + + queue_entry.oldestInst = readyInsts[op_class].top()->seqNum; + + ListOrderIt list_it = listOrder.begin(); + ListOrderIt list_end_it = listOrder.end(); + + while (list_it != list_end_it) { + if ((*list_it).oldestInst > queue_entry.oldestInst) { + break; + } + + list_it++; + } + + readyIt[op_class] = listOrder.insert(list_it, queue_entry); + queueOnList[op_class] = true; +} + +template <class Impl> +void +InstructionQueue<Impl>::moveToYoungerInst(ListOrderIt list_order_it) +{ + // Get iterator of next item on the list + // Delete the original iterator + // Determine if the next item is either the end of the list or younger + // than the new instruction. If so, then add in a new iterator right here. + // If not, then move along. + ListOrderEntry queue_entry; + OpClass op_class = (*list_order_it).queueType; + ListOrderIt next_it = list_order_it; + + ++next_it; + + queue_entry.queueType = op_class; + queue_entry.oldestInst = readyInsts[op_class].top()->seqNum; + + while (next_it != listOrder.end() && + (*next_it).oldestInst < queue_entry.oldestInst) { + ++next_it; + } + + readyIt[op_class] = listOrder.insert(next_it, queue_entry); +} + +template <class Impl> +void +InstructionQueue<Impl>::processFUCompletion(DynInstPtr &inst, int fu_idx) +{ + DPRINTF(IQ, "Processing FU completion [sn:%lli]\n", inst->seqNum); + // The CPU could have been sleeping until this op completed (*extremely* + // long latency op). Wake it if it was. This may be overkill. + if (isSwitchedOut()) { + DPRINTF(IQ, "FU completion not processed, IQ is switched out [sn:%lli]\n", + inst->seqNum); + return; + } + + iewStage->wakeCPU(); + + if (fu_idx > -1) + fuPool->freeUnitNextCycle(fu_idx); + + // @todo: Ensure that these FU Completions happen at the beginning + // of a cycle, otherwise they could add too many instructions to + // the queue. + issueToExecuteQueue->access(0)->size++; + instsToExecute.push_back(inst); +} + +// @todo: Figure out a better way to remove the squashed items from the +// lists. Checking the top item of each list to see if it's squashed +// wastes time and forces jumps. +template <class Impl> +void +InstructionQueue<Impl>::scheduleReadyInsts() +{ + DPRINTF(IQ, "Attempting to schedule ready instructions from " + "the IQ.\n"); + + IssueStruct *i2e_info = issueToExecuteQueue->access(0); + + // Have iterator to head of the list + // While I haven't exceeded bandwidth or reached the end of the list, + // Try to get a FU that can do what this op needs. + // If successful, change the oldestInst to the new top of the list, put + // the queue in the proper place in the list. + // Increment the iterator. + // This will avoid trying to schedule a certain op class if there are no + // FUs that handle it. + ListOrderIt order_it = listOrder.begin(); + ListOrderIt order_end_it = listOrder.end(); + int total_issued = 0; + + while (total_issued < totalWidth && + iewStage->canIssue() && + order_it != order_end_it) { + OpClass op_class = (*order_it).queueType; + + assert(!readyInsts[op_class].empty()); + + DynInstPtr issuing_inst = readyInsts[op_class].top(); + + assert(issuing_inst->seqNum == (*order_it).oldestInst); + + if (issuing_inst->isSquashed()) { + readyInsts[op_class].pop(); + + if (!readyInsts[op_class].empty()) { + moveToYoungerInst(order_it); + } else { + readyIt[op_class] = listOrder.end(); + queueOnList[op_class] = false; + } + + listOrder.erase(order_it++); + + ++iqSquashedInstsIssued; + + continue; + } + + int idx = -2; + int op_latency = 1; + int tid = issuing_inst->threadNumber; + + if (op_class != No_OpClass) { + idx = fuPool->getUnit(op_class); + + if (idx > -1) { + op_latency = fuPool->getOpLatency(op_class); + } + } + + // If we have an instruction that doesn't require a FU, or a + // valid FU, then schedule for execution. + if (idx == -2 || idx != -1) { + if (op_latency == 1) { + i2e_info->size++; + instsToExecute.push_back(issuing_inst); + + // Add the FU onto the list of FU's to be freed next + // cycle if we used one. + if (idx >= 0) + fuPool->freeUnitNextCycle(idx); + } else { + int issue_latency = fuPool->getIssueLatency(op_class); + // Generate completion event for the FU + FUCompletion *execution = new FUCompletion(issuing_inst, + idx, this); + + execution->schedule(curTick + cpu->cycles(issue_latency - 1)); + + // @todo: Enforce that issue_latency == 1 or op_latency + if (issue_latency > 1) { + // If FU isn't pipelined, then it must be freed + // upon the execution completing. + execution->setFreeFU(); + } else { + // Add the FU onto the list of FU's to be freed next cycle. + fuPool->freeUnitNextCycle(idx); + } + } + + DPRINTF(IQ, "Thread %i: Issuing instruction PC %#x " + "[sn:%lli]\n", + tid, issuing_inst->readPC(), + issuing_inst->seqNum); + + readyInsts[op_class].pop(); + + if (!readyInsts[op_class].empty()) { + moveToYoungerInst(order_it); + } else { + readyIt[op_class] = listOrder.end(); + queueOnList[op_class] = false; + } + + issuing_inst->setIssued(); + ++total_issued; + + if (!issuing_inst->isMemRef()) { + // Memory instructions can not be freed from the IQ until they + // complete. + ++freeEntries; + count[tid]--; + issuing_inst->clearInIQ(); + } else { + memDepUnit[tid].issue(issuing_inst); + } + + listOrder.erase(order_it++); + statIssuedInstType[tid][op_class]++; + iewStage->incrWb(issuing_inst->seqNum); + } else { + statFuBusy[op_class]++; + fuBusy[tid]++; + ++order_it; + } + } + + numIssuedDist.sample(total_issued); + iqInstsIssued+= total_issued; + + // If we issued any instructions, tell the CPU we had activity. + if (total_issued) { + cpu->activityThisCycle(); + } else { + DPRINTF(IQ, "Not able to schedule any instructions.\n"); + } +} + +template <class Impl> +void +InstructionQueue<Impl>::scheduleNonSpec(const InstSeqNum &inst) +{ + DPRINTF(IQ, "Marking nonspeculative instruction [sn:%lli] as ready " + "to execute.\n", inst); + + NonSpecMapIt inst_it = nonSpecInsts.find(inst); + + assert(inst_it != nonSpecInsts.end()); + + unsigned tid = (*inst_it).second->threadNumber; + + (*inst_it).second->setCanIssue(); + + if (!(*inst_it).second->isMemRef()) { + addIfReady((*inst_it).second); + } else { + memDepUnit[tid].nonSpecInstReady((*inst_it).second); + } + + (*inst_it).second = NULL; + + nonSpecInsts.erase(inst_it); +} + +template <class Impl> +void +InstructionQueue<Impl>::commit(const InstSeqNum &inst, unsigned tid) +{ + DPRINTF(IQ, "[tid:%i]: Committing instructions older than [sn:%i]\n", + tid,inst); + + ListIt iq_it = instList[tid].begin(); + + while (iq_it != instList[tid].end() && + (*iq_it)->seqNum <= inst) { + ++iq_it; + instList[tid].pop_front(); + } + + assert(freeEntries == (numEntries - countInsts())); +} + +template <class Impl> +int +InstructionQueue<Impl>::wakeDependents(DynInstPtr &completed_inst) +{ + int dependents = 0; + + DPRINTF(IQ, "Waking dependents of completed instruction.\n"); + + assert(!completed_inst->isSquashed()); + + // Tell the memory dependence unit to wake any dependents on this + // instruction if it is a memory instruction. Also complete the memory + // instruction at this point since we know it executed without issues. + // @todo: Might want to rename "completeMemInst" to something that + // indicates that it won't need to be replayed, and call this + // earlier. Might not be a big deal. + if (completed_inst->isMemRef()) { + memDepUnit[completed_inst->threadNumber].wakeDependents(completed_inst); + completeMemInst(completed_inst); + } else if (completed_inst->isMemBarrier() || + completed_inst->isWriteBarrier()) { + memDepUnit[completed_inst->threadNumber].completeBarrier(completed_inst); + } + + for (int dest_reg_idx = 0; + dest_reg_idx < completed_inst->numDestRegs(); + dest_reg_idx++) + { + PhysRegIndex dest_reg = + completed_inst->renamedDestRegIdx(dest_reg_idx); + + // Special case of uniq or control registers. They are not + // handled by the IQ and thus have no dependency graph entry. + // @todo Figure out a cleaner way to handle this. + if (dest_reg >= numPhysRegs) { + continue; + } + + DPRINTF(IQ, "Waking any dependents on register %i.\n", + (int) dest_reg); + + //Go through the dependency chain, marking the registers as + //ready within the waiting instructions. + DynInstPtr dep_inst = dependGraph.pop(dest_reg); + + while (dep_inst) { + DPRINTF(IQ, "Waking up a dependent instruction, PC%#x.\n", + dep_inst->readPC()); + + // Might want to give more information to the instruction + // so that it knows which of its source registers is + // ready. However that would mean that the dependency + // graph entries would need to hold the src_reg_idx. + dep_inst->markSrcRegReady(); + + addIfReady(dep_inst); + + dep_inst = dependGraph.pop(dest_reg); + + ++dependents; + } + + // Reset the head node now that all of its dependents have + // been woken up. + assert(dependGraph.empty(dest_reg)); + dependGraph.clearInst(dest_reg); + + // Mark the scoreboard as having that register ready. + regScoreboard[dest_reg] = true; + } + return dependents; +} + +template <class Impl> +void +InstructionQueue<Impl>::addReadyMemInst(DynInstPtr &ready_inst) +{ + OpClass op_class = ready_inst->opClass(); + + readyInsts[op_class].push(ready_inst); + + // Will need to reorder the list if either a queue is not on the list, + // or it has an older instruction than last time. + if (!queueOnList[op_class]) { + addToOrderList(op_class); + } else if (readyInsts[op_class].top()->seqNum < + (*readyIt[op_class]).oldestInst) { + listOrder.erase(readyIt[op_class]); + addToOrderList(op_class); + } + + DPRINTF(IQ, "Instruction is ready to issue, putting it onto " + "the ready list, PC %#x opclass:%i [sn:%lli].\n", + ready_inst->readPC(), op_class, ready_inst->seqNum); +} + +template <class Impl> +void +InstructionQueue<Impl>::rescheduleMemInst(DynInstPtr &resched_inst) +{ + memDepUnit[resched_inst->threadNumber].reschedule(resched_inst); +} + +template <class Impl> +void +InstructionQueue<Impl>::replayMemInst(DynInstPtr &replay_inst) +{ + memDepUnit[replay_inst->threadNumber].replay(replay_inst); +} + +template <class Impl> +void +InstructionQueue<Impl>::completeMemInst(DynInstPtr &completed_inst) +{ + int tid = completed_inst->threadNumber; + + DPRINTF(IQ, "Completing mem instruction PC:%#x [sn:%lli]\n", + completed_inst->readPC(), completed_inst->seqNum); + + ++freeEntries; + + completed_inst->memOpDone = true; + + memDepUnit[tid].completed(completed_inst); + + count[tid]--; +} + +template <class Impl> +void +InstructionQueue<Impl>::violation(DynInstPtr &store, + DynInstPtr &faulting_load) +{ + memDepUnit[store->threadNumber].violation(store, faulting_load); +} + +template <class Impl> +void +InstructionQueue<Impl>::squash(unsigned tid) +{ + DPRINTF(IQ, "[tid:%i]: Starting to squash instructions in " + "the IQ.\n", tid); + + // Read instruction sequence number of last instruction out of the + // time buffer. +#if ISA_HAS_DELAY_SLOT + squashedSeqNum[tid] = fromCommit->commitInfo[tid].bdelayDoneSeqNum; +#else + squashedSeqNum[tid] = fromCommit->commitInfo[tid].doneSeqNum; +#endif + + // Call doSquash if there are insts in the IQ + if (count[tid] > 0) { + doSquash(tid); + } + + // Also tell the memory dependence unit to squash. + memDepUnit[tid].squash(squashedSeqNum[tid], tid); +} + +template <class Impl> +void +InstructionQueue<Impl>::doSquash(unsigned tid) +{ + // Start at the tail. + ListIt squash_it = instList[tid].end(); + --squash_it; + + DPRINTF(IQ, "[tid:%i]: Squashing until sequence number %i!\n", + tid, squashedSeqNum[tid]); + + // Squash any instructions younger than the squashed sequence number + // given. + while (squash_it != instList[tid].end() && + (*squash_it)->seqNum > squashedSeqNum[tid]) { + + DynInstPtr squashed_inst = (*squash_it); + + // Only handle the instruction if it actually is in the IQ and + // hasn't already been squashed in the IQ. + if (squashed_inst->threadNumber != tid || + squashed_inst->isSquashedInIQ()) { + --squash_it; + continue; + } + + if (!squashed_inst->isIssued() || + (squashed_inst->isMemRef() && + !squashed_inst->memOpDone)) { + + DPRINTF(IQ, "[tid:%i]: Instruction [sn:%lli] PC %#x " + "squashed.\n", + tid, squashed_inst->seqNum, squashed_inst->readPC()); + + // Remove the instruction from the dependency list. + if (!squashed_inst->isNonSpeculative() && + !squashed_inst->isStoreConditional() && + !squashed_inst->isMemBarrier() && + !squashed_inst->isWriteBarrier()) { + + for (int src_reg_idx = 0; + src_reg_idx < squashed_inst->numSrcRegs(); + src_reg_idx++) + { + PhysRegIndex src_reg = + squashed_inst->renamedSrcRegIdx(src_reg_idx); + + // Only remove it from the dependency graph if it + // was placed there in the first place. + + // Instead of doing a linked list traversal, we + // can just remove these squashed instructions + // either at issue time, or when the register is + // overwritten. The only downside to this is it + // leaves more room for error. + + if (!squashed_inst->isReadySrcRegIdx(src_reg_idx) && + src_reg < numPhysRegs) { + dependGraph.remove(src_reg, squashed_inst); + } + + + ++iqSquashedOperandsExamined; + } + } else if (!squashed_inst->isStoreConditional() || !squashed_inst->isCompleted()) { + NonSpecMapIt ns_inst_it = + nonSpecInsts.find(squashed_inst->seqNum); + assert(ns_inst_it != nonSpecInsts.end()); + + (*ns_inst_it).second = NULL; + + nonSpecInsts.erase(ns_inst_it); + + ++iqSquashedNonSpecRemoved; + } + + // Might want to also clear out the head of the dependency graph. + + // Mark it as squashed within the IQ. + squashed_inst->setSquashedInIQ(); + + // @todo: Remove this hack where several statuses are set so the + // inst will flow through the rest of the pipeline. + squashed_inst->setIssued(); + squashed_inst->setCanCommit(); + squashed_inst->clearInIQ(); + + //Update Thread IQ Count + count[squashed_inst->threadNumber]--; + + ++freeEntries; + } + + instList[tid].erase(squash_it--); + ++iqSquashedInstsExamined; + } +} + +template <class Impl> +bool +InstructionQueue<Impl>::addToDependents(DynInstPtr &new_inst) +{ + // Loop through the instruction's source registers, adding + // them to the dependency list if they are not ready. + int8_t total_src_regs = new_inst->numSrcRegs(); + bool return_val = false; + + for (int src_reg_idx = 0; + src_reg_idx < total_src_regs; + src_reg_idx++) + { + // Only add it to the dependency graph if it's not ready. + if (!new_inst->isReadySrcRegIdx(src_reg_idx)) { + PhysRegIndex src_reg = new_inst->renamedSrcRegIdx(src_reg_idx); + + // Check the IQ's scoreboard to make sure the register + // hasn't become ready while the instruction was in flight + // between stages. Only if it really isn't ready should + // it be added to the dependency graph. + if (src_reg >= numPhysRegs) { + continue; + } else if (regScoreboard[src_reg] == false) { + DPRINTF(IQ, "Instruction PC %#x has src reg %i that " + "is being added to the dependency chain.\n", + new_inst->readPC(), src_reg); + + dependGraph.insert(src_reg, new_inst); + + // Change the return value to indicate that something + // was added to the dependency graph. + return_val = true; + } else { + DPRINTF(IQ, "Instruction PC %#x has src reg %i that " + "became ready before it reached the IQ.\n", + new_inst->readPC(), src_reg); + // Mark a register ready within the instruction. + new_inst->markSrcRegReady(src_reg_idx); + } + } + } + + return return_val; +} + +template <class Impl> +void +InstructionQueue<Impl>::addToProducers(DynInstPtr &new_inst) +{ + // Nothing really needs to be marked when an instruction becomes + // the producer of a register's value, but for convenience a ptr + // to the producing instruction will be placed in the head node of + // the dependency links. + int8_t total_dest_regs = new_inst->numDestRegs(); + + for (int dest_reg_idx = 0; + dest_reg_idx < total_dest_regs; + dest_reg_idx++) + { + PhysRegIndex dest_reg = new_inst->renamedDestRegIdx(dest_reg_idx); + + // Instructions that use the misc regs will have a reg number + // higher than the normal physical registers. In this case these + // registers are not renamed, and there is no need to track + // dependencies as these instructions must be executed at commit. + if (dest_reg >= numPhysRegs) { + continue; + } + + if (!dependGraph.empty(dest_reg)) { + dependGraph.dump(); + panic("Dependency graph %i not empty!", dest_reg); + } + + dependGraph.setInst(dest_reg, new_inst); + + // Mark the scoreboard to say it's not yet ready. + regScoreboard[dest_reg] = false; + } +} + +template <class Impl> +void +InstructionQueue<Impl>::addIfReady(DynInstPtr &inst) +{ + // If the instruction now has all of its source registers + // available, then add it to the list of ready instructions. + if (inst->readyToIssue()) { + + //Add the instruction to the proper ready list. + if (inst->isMemRef()) { + + DPRINTF(IQ, "Checking if memory instruction can issue.\n"); + + // Message to the mem dependence unit that this instruction has + // its registers ready. + memDepUnit[inst->threadNumber].regsReady(inst); + + return; + } + + OpClass op_class = inst->opClass(); + + DPRINTF(IQ, "Instruction is ready to issue, putting it onto " + "the ready list, PC %#x opclass:%i [sn:%lli].\n", + inst->readPC(), op_class, inst->seqNum); + + readyInsts[op_class].push(inst); + + // Will need to reorder the list if either a queue is not on the list, + // or it has an older instruction than last time. + if (!queueOnList[op_class]) { + addToOrderList(op_class); + } else if (readyInsts[op_class].top()->seqNum < + (*readyIt[op_class]).oldestInst) { + listOrder.erase(readyIt[op_class]); + addToOrderList(op_class); + } + } +} + +template <class Impl> +int +InstructionQueue<Impl>::countInsts() +{ +#if 0 + //ksewell:This works but definitely could use a cleaner write + //with a more intuitive way of counting. Right now it's + //just brute force .... + // Change the #if if you want to use this method. + int total_insts = 0; + + for (int i = 0; i < numThreads; ++i) { + ListIt count_it = instList[i].begin(); + + while (count_it != instList[i].end()) { + if (!(*count_it)->isSquashed() && !(*count_it)->isSquashedInIQ()) { + if (!(*count_it)->isIssued()) { + ++total_insts; + } else if ((*count_it)->isMemRef() && + !(*count_it)->memOpDone) { + // Loads that have not been marked as executed still count + // towards the total instructions. + ++total_insts; + } + } + + ++count_it; + } + } + + return total_insts; +#else + return numEntries - freeEntries; +#endif +} + +template <class Impl> +void +InstructionQueue<Impl>::dumpLists() +{ + for (int i = 0; i < Num_OpClasses; ++i) { + cprintf("Ready list %i size: %i\n", i, readyInsts[i].size()); + + cprintf("\n"); + } + + cprintf("Non speculative list size: %i\n", nonSpecInsts.size()); + + NonSpecMapIt non_spec_it = nonSpecInsts.begin(); + NonSpecMapIt non_spec_end_it = nonSpecInsts.end(); + + cprintf("Non speculative list: "); + + while (non_spec_it != non_spec_end_it) { + cprintf("%#x [sn:%lli]", (*non_spec_it).second->readPC(), + (*non_spec_it).second->seqNum); + ++non_spec_it; + } + + cprintf("\n"); + + ListOrderIt list_order_it = listOrder.begin(); + ListOrderIt list_order_end_it = listOrder.end(); + int i = 1; + + cprintf("List order: "); + + while (list_order_it != list_order_end_it) { + cprintf("%i OpClass:%i [sn:%lli] ", i, (*list_order_it).queueType, + (*list_order_it).oldestInst); + + ++list_order_it; + ++i; + } + + cprintf("\n"); +} + + +template <class Impl> +void +InstructionQueue<Impl>::dumpInsts() +{ + for (int i = 0; i < numThreads; ++i) { + int num = 0; + int valid_num = 0; + ListIt inst_list_it = instList[i].begin(); + + while (inst_list_it != instList[i].end()) + { + cprintf("Instruction:%i\n", + num); + if (!(*inst_list_it)->isSquashed()) { + if (!(*inst_list_it)->isIssued()) { + ++valid_num; + cprintf("Count:%i\n", valid_num); + } else if ((*inst_list_it)->isMemRef() && + !(*inst_list_it)->memOpDone) { + // Loads that have not been marked as executed + // still count towards the total instructions. + ++valid_num; + cprintf("Count:%i\n", valid_num); + } + } + + cprintf("PC:%#x\n[sn:%lli]\n[tid:%i]\n" + "Issued:%i\nSquashed:%i\n", + (*inst_list_it)->readPC(), + (*inst_list_it)->seqNum, + (*inst_list_it)->threadNumber, + (*inst_list_it)->isIssued(), + (*inst_list_it)->isSquashed()); + + if ((*inst_list_it)->isMemRef()) { + cprintf("MemOpDone:%i\n", (*inst_list_it)->memOpDone); + } + + cprintf("\n"); + + inst_list_it++; + ++num; + } + } + + cprintf("Insts to Execute list:\n"); + + int num = 0; + int valid_num = 0; + ListIt inst_list_it = instsToExecute.begin(); + + while (inst_list_it != instsToExecute.end()) + { + cprintf("Instruction:%i\n", + num); + if (!(*inst_list_it)->isSquashed()) { + if (!(*inst_list_it)->isIssued()) { + ++valid_num; + cprintf("Count:%i\n", valid_num); + } else if ((*inst_list_it)->isMemRef() && + !(*inst_list_it)->memOpDone) { + // Loads that have not been marked as executed + // still count towards the total instructions. + ++valid_num; + cprintf("Count:%i\n", valid_num); + } + } + + cprintf("PC:%#x\n[sn:%lli]\n[tid:%i]\n" + "Issued:%i\nSquashed:%i\n", + (*inst_list_it)->readPC(), + (*inst_list_it)->seqNum, + (*inst_list_it)->threadNumber, + (*inst_list_it)->isIssued(), + (*inst_list_it)->isSquashed()); + + if ((*inst_list_it)->isMemRef()) { + cprintf("MemOpDone:%i\n", (*inst_list_it)->memOpDone); + } + + cprintf("\n"); + + inst_list_it++; + ++num; + } +} |