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Diffstat (limited to 'cpu/o3/commit_impl.hh')
| -rw-r--r-- | cpu/o3/commit_impl.hh | 1307 |
1 files changed, 0 insertions, 1307 deletions
diff --git a/cpu/o3/commit_impl.hh b/cpu/o3/commit_impl.hh deleted file mode 100644 index 346a8bc1c..000000000 --- a/cpu/o3/commit_impl.hh +++ /dev/null @@ -1,1307 +0,0 @@ -/* - * 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. - */ - -#include <algorithm> -#include <string> - -#include "base/loader/symtab.hh" -#include "base/timebuf.hh" -#include "cpu/checker/cpu.hh" -#include "cpu/exetrace.hh" -#include "cpu/o3/commit.hh" -#include "cpu/o3/thread_state.hh" - -using namespace std; - -template <class Impl> -DefaultCommit<Impl>::TrapEvent::TrapEvent(DefaultCommit<Impl> *_commit, - unsigned _tid) - : Event(&mainEventQueue, CPU_Tick_Pri), commit(_commit), tid(_tid) -{ - this->setFlags(Event::AutoDelete); -} - -template <class Impl> -void -DefaultCommit<Impl>::TrapEvent::process() -{ - // This will get reset by commit if it was switched out at the - // time of this event processing. - commit->trapSquash[tid] = true; -} - -template <class Impl> -const char * -DefaultCommit<Impl>::TrapEvent::description() -{ - return "Trap event"; -} - -template <class Impl> -DefaultCommit<Impl>::DefaultCommit(Params *params) - : dcacheInterface(params->dcacheInterface), - squashCounter(0), - iewToCommitDelay(params->iewToCommitDelay), - commitToIEWDelay(params->commitToIEWDelay), - renameToROBDelay(params->renameToROBDelay), - fetchToCommitDelay(params->commitToFetchDelay), - renameWidth(params->renameWidth), - iewWidth(params->executeWidth), - commitWidth(params->commitWidth), - numThreads(params->numberOfThreads), - switchedOut(false), - trapLatency(params->trapLatency), - fetchTrapLatency(params->fetchTrapLatency) -{ - _status = Active; - _nextStatus = Inactive; - string policy = params->smtCommitPolicy; - - //Convert string to lowercase - std::transform(policy.begin(), policy.end(), policy.begin(), - (int(*)(int)) tolower); - - //Assign commit policy - if (policy == "aggressive"){ - commitPolicy = Aggressive; - - DPRINTF(Commit,"Commit Policy set to Aggressive."); - } else if (policy == "roundrobin"){ - commitPolicy = RoundRobin; - - //Set-Up Priority List - for (int tid=0; tid < numThreads; tid++) { - priority_list.push_back(tid); - } - - DPRINTF(Commit,"Commit Policy set to Round Robin."); - } else if (policy == "oldestready"){ - commitPolicy = OldestReady; - - DPRINTF(Commit,"Commit Policy set to Oldest Ready."); - } else { - assert(0 && "Invalid SMT Commit Policy. Options Are: {Aggressive," - "RoundRobin,OldestReady}"); - } - - for (int i=0; i < numThreads; i++) { - commitStatus[i] = Idle; - changedROBNumEntries[i] = false; - trapSquash[i] = false; - xcSquash[i] = false; - } - - fetchFaultTick = 0; - fetchTrapWait = 0; -} - -template <class Impl> -std::string -DefaultCommit<Impl>::name() const -{ - return cpu->name() + ".commit"; -} - -template <class Impl> -void -DefaultCommit<Impl>::regStats() -{ - using namespace Stats; - commitCommittedInsts - .name(name() + ".commitCommittedInsts") - .desc("The number of committed instructions") - .prereq(commitCommittedInsts); - commitSquashedInsts - .name(name() + ".commitSquashedInsts") - .desc("The number of squashed insts skipped by commit") - .prereq(commitSquashedInsts); - commitSquashEvents - .name(name() + ".commitSquashEvents") - .desc("The number of times commit is told to squash") - .prereq(commitSquashEvents); - commitNonSpecStalls - .name(name() + ".commitNonSpecStalls") - .desc("The number of times commit has been forced to stall to " - "communicate backwards") - .prereq(commitNonSpecStalls); - branchMispredicts - .name(name() + ".branchMispredicts") - .desc("The number of times a branch was mispredicted") - .prereq(branchMispredicts); - numCommittedDist - .init(0,commitWidth,1) - .name(name() + ".COM:committed_per_cycle") - .desc("Number of insts commited each cycle") - .flags(Stats::pdf) - ; - - statComInst - .init(cpu->number_of_threads) - .name(name() + ".COM:count") - .desc("Number of instructions committed") - .flags(total) - ; - - statComSwp - .init(cpu->number_of_threads) - .name(name() + ".COM:swp_count") - .desc("Number of s/w prefetches committed") - .flags(total) - ; - - statComRefs - .init(cpu->number_of_threads) - .name(name() + ".COM:refs") - .desc("Number of memory references committed") - .flags(total) - ; - - statComLoads - .init(cpu->number_of_threads) - .name(name() + ".COM:loads") - .desc("Number of loads committed") - .flags(total) - ; - - statComMembars - .init(cpu->number_of_threads) - .name(name() + ".COM:membars") - .desc("Number of memory barriers committed") - .flags(total) - ; - - statComBranches - .init(cpu->number_of_threads) - .name(name() + ".COM:branches") - .desc("Number of branches committed") - .flags(total) - ; - - // - // Commit-Eligible instructions... - // - // -> The number of instructions eligible to commit in those - // cycles where we reached our commit BW limit (less the number - // actually committed) - // - // -> The average value is computed over ALL CYCLES... not just - // the BW limited cycles - // - // -> The standard deviation is computed only over cycles where - // we reached the BW limit - // - commitEligible - .init(cpu->number_of_threads) - .name(name() + ".COM:bw_limited") - .desc("number of insts not committed due to BW limits") - .flags(total) - ; - - commitEligibleSamples - .name(name() + ".COM:bw_lim_events") - .desc("number cycles where commit BW limit reached") - ; -} - -template <class Impl> -void -DefaultCommit<Impl>::setCPU(FullCPU *cpu_ptr) -{ - DPRINTF(Commit, "Commit: Setting CPU pointer.\n"); - cpu = cpu_ptr; - - // Commit must broadcast the number of free entries it has at the start of - // the simulation, so it starts as active. - cpu->activateStage(FullCPU::CommitIdx); - - trapLatency = cpu->cycles(trapLatency); - fetchTrapLatency = cpu->cycles(fetchTrapLatency); -} - -template <class Impl> -void -DefaultCommit<Impl>::setThreads(vector<Thread *> &threads) -{ - thread = threads; -} - -template <class Impl> -void -DefaultCommit<Impl>::setTimeBuffer(TimeBuffer<TimeStruct> *tb_ptr) -{ - DPRINTF(Commit, "Commit: Setting time buffer pointer.\n"); - timeBuffer = tb_ptr; - - // Setup wire to send information back to IEW. - toIEW = timeBuffer->getWire(0); - - // Setup wire to read data from IEW (for the ROB). - robInfoFromIEW = timeBuffer->getWire(-iewToCommitDelay); -} - -template <class Impl> -void -DefaultCommit<Impl>::setFetchQueue(TimeBuffer<FetchStruct> *fq_ptr) -{ - DPRINTF(Commit, "Commit: Setting fetch queue pointer.\n"); - fetchQueue = fq_ptr; - - // Setup wire to get instructions from rename (for the ROB). - fromFetch = fetchQueue->getWire(-fetchToCommitDelay); -} - -template <class Impl> -void -DefaultCommit<Impl>::setRenameQueue(TimeBuffer<RenameStruct> *rq_ptr) -{ - DPRINTF(Commit, "Commit: Setting rename queue pointer.\n"); - renameQueue = rq_ptr; - - // Setup wire to get instructions from rename (for the ROB). - fromRename = renameQueue->getWire(-renameToROBDelay); -} - -template <class Impl> -void -DefaultCommit<Impl>::setIEWQueue(TimeBuffer<IEWStruct> *iq_ptr) -{ - DPRINTF(Commit, "Commit: Setting IEW queue pointer.\n"); - iewQueue = iq_ptr; - - // Setup wire to get instructions from IEW. - fromIEW = iewQueue->getWire(-iewToCommitDelay); -} - -template <class Impl> -void -DefaultCommit<Impl>::setFetchStage(Fetch *fetch_stage) -{ - fetchStage = fetch_stage; -} - -template <class Impl> -void -DefaultCommit<Impl>::setIEWStage(IEW *iew_stage) -{ - iewStage = iew_stage; -} - -template<class Impl> -void -DefaultCommit<Impl>::setActiveThreads(list<unsigned> *at_ptr) -{ - DPRINTF(Commit, "Commit: Setting active threads list pointer.\n"); - activeThreads = at_ptr; -} - -template <class Impl> -void -DefaultCommit<Impl>::setRenameMap(RenameMap rm_ptr[]) -{ - DPRINTF(Commit, "Setting rename map pointers.\n"); - - for (int i=0; i < numThreads; i++) { - renameMap[i] = &rm_ptr[i]; - } -} - -template <class Impl> -void -DefaultCommit<Impl>::setROB(ROB *rob_ptr) -{ - DPRINTF(Commit, "Commit: Setting ROB pointer.\n"); - rob = rob_ptr; -} - -template <class Impl> -void -DefaultCommit<Impl>::initStage() -{ - rob->setActiveThreads(activeThreads); - rob->resetEntries(); - - // Broadcast the number of free entries. - for (int i=0; i < numThreads; i++) { - toIEW->commitInfo[i].usedROB = true; - toIEW->commitInfo[i].freeROBEntries = rob->numFreeEntries(i); - } - - cpu->activityThisCycle(); -} - -template <class Impl> -void -DefaultCommit<Impl>::switchOut() -{ - switchPending = true; -} - -template <class Impl> -void -DefaultCommit<Impl>::doSwitchOut() -{ - switchedOut = true; - switchPending = false; - rob->switchOut(); -} - -template <class Impl> -void -DefaultCommit<Impl>::takeOverFrom() -{ - switchedOut = false; - _status = Active; - _nextStatus = Inactive; - for (int i=0; i < numThreads; i++) { - commitStatus[i] = Idle; - changedROBNumEntries[i] = false; - trapSquash[i] = false; - xcSquash[i] = false; - } - squashCounter = 0; - rob->takeOverFrom(); -} - -template <class Impl> -void -DefaultCommit<Impl>::updateStatus() -{ - // reset ROB changed variable - list<unsigned>::iterator threads = (*activeThreads).begin(); - while (threads != (*activeThreads).end()) { - unsigned tid = *threads++; - changedROBNumEntries[tid] = false; - - // Also check if any of the threads has a trap pending - if (commitStatus[tid] == TrapPending || - commitStatus[tid] == FetchTrapPending) { - _nextStatus = Active; - } - } - - if (_nextStatus == Inactive && _status == Active) { - DPRINTF(Activity, "Deactivating stage.\n"); - cpu->deactivateStage(FullCPU::CommitIdx); - } else if (_nextStatus == Active && _status == Inactive) { - DPRINTF(Activity, "Activating stage.\n"); - cpu->activateStage(FullCPU::CommitIdx); - } - - _status = _nextStatus; -} - -template <class Impl> -void -DefaultCommit<Impl>::setNextStatus() -{ - int squashes = 0; - - list<unsigned>::iterator threads = (*activeThreads).begin(); - - while (threads != (*activeThreads).end()) { - unsigned tid = *threads++; - - if (commitStatus[tid] == ROBSquashing) { - squashes++; - } - } - - assert(squashes == squashCounter); - - // If commit is currently squashing, then it will have activity for the - // next cycle. Set its next status as active. - if (squashCounter) { - _nextStatus = Active; - } -} - -template <class Impl> -bool -DefaultCommit<Impl>::changedROBEntries() -{ - list<unsigned>::iterator threads = (*activeThreads).begin(); - - while (threads != (*activeThreads).end()) { - unsigned tid = *threads++; - - if (changedROBNumEntries[tid]) { - return true; - } - } - - return false; -} - -template <class Impl> -unsigned -DefaultCommit<Impl>::numROBFreeEntries(unsigned tid) -{ - return rob->numFreeEntries(tid); -} - -template <class Impl> -void -DefaultCommit<Impl>::generateTrapEvent(unsigned tid) -{ - DPRINTF(Commit, "Generating trap event for [tid:%i]\n", tid); - - TrapEvent *trap = new TrapEvent(this, tid); - - trap->schedule(curTick + trapLatency); - - thread[tid]->trapPending = true; -} - -template <class Impl> -void -DefaultCommit<Impl>::generateXCEvent(unsigned tid) -{ - DPRINTF(Commit, "Generating XC squash event for [tid:%i]\n", tid); - - xcSquash[tid] = true; -} - -template <class Impl> -void -DefaultCommit<Impl>::squashAll(unsigned tid) -{ - // If we want to include the squashing instruction in the squash, - // then use one older sequence number. - // Hopefully this doesn't mess things up. Basically I want to squash - // all instructions of this thread. - InstSeqNum squashed_inst = rob->isEmpty() ? - 0 : rob->readHeadInst(tid)->seqNum - 1;; - - // All younger instructions will be squashed. Set the sequence - // number as the youngest instruction in the ROB (0 in this case. - // Hopefully nothing breaks.) - youngestSeqNum[tid] = 0; - - rob->squash(squashed_inst, tid); - changedROBNumEntries[tid] = true; - - // Send back the sequence number of the squashed instruction. - toIEW->commitInfo[tid].doneSeqNum = squashed_inst; - - // Send back the squash signal to tell stages that they should - // squash. - toIEW->commitInfo[tid].squash = true; - - // Send back the rob squashing signal so other stages know that - // the ROB is in the process of squashing. - toIEW->commitInfo[tid].robSquashing = true; - - toIEW->commitInfo[tid].branchMispredict = false; - - toIEW->commitInfo[tid].nextPC = PC[tid]; -} - -template <class Impl> -void -DefaultCommit<Impl>::squashFromTrap(unsigned tid) -{ - squashAll(tid); - - DPRINTF(Commit, "Squashing from trap, restarting at PC %#x\n", PC[tid]); - - thread[tid]->trapPending = false; - thread[tid]->inSyscall = false; - - trapSquash[tid] = false; - - commitStatus[tid] = ROBSquashing; - cpu->activityThisCycle(); - - ++squashCounter; -} - -template <class Impl> -void -DefaultCommit<Impl>::squashFromXC(unsigned tid) -{ - squashAll(tid); - - DPRINTF(Commit, "Squashing from XC, restarting at PC %#x\n", PC[tid]); - - thread[tid]->inSyscall = false; - assert(!thread[tid]->trapPending); - - commitStatus[tid] = ROBSquashing; - cpu->activityThisCycle(); - - xcSquash[tid] = false; - - ++squashCounter; -} - -template <class Impl> -void -DefaultCommit<Impl>::tick() -{ - wroteToTimeBuffer = false; - _nextStatus = Inactive; - - if (switchPending && rob->isEmpty() && !iewStage->hasStoresToWB()) { - cpu->signalSwitched(); - return; - } - - list<unsigned>::iterator threads = (*activeThreads).begin(); - - // Check if any of the threads are done squashing. Change the - // status if they are done. - while (threads != (*activeThreads).end()) { - unsigned tid = *threads++; - - if (commitStatus[tid] == ROBSquashing) { - - if (rob->isDoneSquashing(tid)) { - commitStatus[tid] = Running; - --squashCounter; - } else { - DPRINTF(Commit,"[tid:%u]: Still Squashing, cannot commit any" - "insts this cycle.\n", tid); - } - } - } - - commit(); - - markCompletedInsts(); - - threads = (*activeThreads).begin(); - - while (threads != (*activeThreads).end()) { - unsigned tid = *threads++; - - if (!rob->isEmpty(tid) && rob->readHeadInst(tid)->readyToCommit()) { - // The ROB has more instructions it can commit. Its next status - // will be active. - _nextStatus = Active; - - DynInstPtr inst = rob->readHeadInst(tid); - - DPRINTF(Commit,"[tid:%i]: Instruction [sn:%lli] PC %#x is head of" - " ROB and ready to commit\n", - tid, inst->seqNum, inst->readPC()); - - } else if (!rob->isEmpty(tid)) { - DynInstPtr inst = rob->readHeadInst(tid); - - DPRINTF(Commit,"[tid:%i]: Can't commit, Instruction [sn:%lli] PC " - "%#x is head of ROB and not ready\n", - tid, inst->seqNum, inst->readPC()); - } - - DPRINTF(Commit, "[tid:%i]: ROB has %d insts & %d free entries.\n", - tid, rob->countInsts(tid), rob->numFreeEntries(tid)); - } - - - if (wroteToTimeBuffer) { - DPRINTF(Activity, "Activity This Cycle.\n"); - cpu->activityThisCycle(); - } - - updateStatus(); -} - -template <class Impl> -void -DefaultCommit<Impl>::commit() -{ - - ////////////////////////////////////// - // Check for interrupts - ////////////////////////////////////// - -#if FULL_SYSTEM - // Process interrupts if interrupts are enabled, not in PAL mode, - // and no other traps or external squashes are currently pending. - // @todo: Allow other threads to handle interrupts. - if (cpu->checkInterrupts && - cpu->check_interrupts() && - !cpu->inPalMode(readPC()) && - !trapSquash[0] && - !xcSquash[0]) { - // Tell fetch that there is an interrupt pending. This will - // make fetch wait until it sees a non PAL-mode PC, at which - // point it stops fetching instructions. - toIEW->commitInfo[0].interruptPending = true; - - // Wait until the ROB is empty and all stores have drained in - // order to enter the interrupt. - if (rob->isEmpty() && !iewStage->hasStoresToWB()) { - // Not sure which thread should be the one to interrupt. For now - // always do thread 0. - assert(!thread[0]->inSyscall); - thread[0]->inSyscall = true; - - // CPU will handle implementation of the interrupt. - cpu->processInterrupts(); - - // Now squash or record that I need to squash this cycle. - commitStatus[0] = TrapPending; - - // Exit state update mode to avoid accidental updating. - thread[0]->inSyscall = false; - - // Generate trap squash event. - generateTrapEvent(0); - - toIEW->commitInfo[0].clearInterrupt = true; - - DPRINTF(Commit, "Interrupt detected.\n"); - } else { - DPRINTF(Commit, "Interrupt pending, waiting for ROB to empty.\n"); - } - } -#endif // FULL_SYSTEM - - //////////////////////////////////// - // Check for any possible squashes, handle them first - //////////////////////////////////// - - list<unsigned>::iterator threads = (*activeThreads).begin(); - - while (threads != (*activeThreads).end()) { - unsigned tid = *threads++; - - if (fromFetch->fetchFault && commitStatus[0] != TrapPending) { - // Record the fault. Wait until it's empty in the ROB. - // Then handle the trap. Ignore it if there's already a - // trap pending as fetch will be redirected. - fetchFault = fromFetch->fetchFault; - fetchFaultTick = curTick + fetchTrapLatency; - commitStatus[0] = FetchTrapPending; - DPRINTF(Commit, "Fault from fetch recorded. Will trap if the " - "ROB empties without squashing the fault.\n"); - fetchTrapWait = 0; - } - - // Fetch may tell commit to clear the trap if it's been squashed. - if (fromFetch->clearFetchFault) { - DPRINTF(Commit, "Received clear fetch fault signal\n"); - fetchTrapWait = 0; - if (commitStatus[0] == FetchTrapPending) { - DPRINTF(Commit, "Clearing fault from fetch\n"); - commitStatus[0] = Running; - } - } - - // Not sure which one takes priority. I think if we have - // both, that's a bad sign. - if (trapSquash[tid] == true) { - assert(!xcSquash[tid]); - squashFromTrap(tid); - } else if (xcSquash[tid] == true) { - squashFromXC(tid); - } - - // Squashed sequence number must be older than youngest valid - // instruction in the ROB. This prevents squashes from younger - // instructions overriding squashes from older instructions. - if (fromIEW->squash[tid] && - commitStatus[tid] != TrapPending && - fromIEW->squashedSeqNum[tid] <= youngestSeqNum[tid]) { - - DPRINTF(Commit, "[tid:%i]: Squashing due to PC %#x [sn:%i]\n", - tid, - fromIEW->mispredPC[tid], - fromIEW->squashedSeqNum[tid]); - - DPRINTF(Commit, "[tid:%i]: Redirecting to PC %#x\n", - tid, - fromIEW->nextPC[tid]); - - commitStatus[tid] = ROBSquashing; - - ++squashCounter; - - // If we want to include the squashing instruction in the squash, - // then use one older sequence number. - InstSeqNum squashed_inst = fromIEW->squashedSeqNum[tid]; - - if (fromIEW->includeSquashInst[tid] == true) - squashed_inst--; - - // All younger instructions will be squashed. Set the sequence - // number as the youngest instruction in the ROB. - youngestSeqNum[tid] = squashed_inst; - - rob->squash(squashed_inst, tid); - changedROBNumEntries[tid] = true; - - toIEW->commitInfo[tid].doneSeqNum = squashed_inst; - - toIEW->commitInfo[tid].squash = true; - - // Send back the rob squashing signal so other stages know that - // the ROB is in the process of squashing. - toIEW->commitInfo[tid].robSquashing = true; - - toIEW->commitInfo[tid].branchMispredict = - fromIEW->branchMispredict[tid]; - - toIEW->commitInfo[tid].branchTaken = - fromIEW->branchTaken[tid]; - - toIEW->commitInfo[tid].nextPC = fromIEW->nextPC[tid]; - - toIEW->commitInfo[tid].mispredPC = fromIEW->mispredPC[tid]; - - if (toIEW->commitInfo[tid].branchMispredict) { - ++branchMispredicts; - } - } - - } - - setNextStatus(); - - if (squashCounter != numThreads) { - // If we're not currently squashing, then get instructions. - getInsts(); - - // Try to commit any instructions. - commitInsts(); - } - - //Check for any activity - threads = (*activeThreads).begin(); - - while (threads != (*activeThreads).end()) { - unsigned tid = *threads++; - - if (changedROBNumEntries[tid]) { - toIEW->commitInfo[tid].usedROB = true; - toIEW->commitInfo[tid].freeROBEntries = rob->numFreeEntries(tid); - - if (rob->isEmpty(tid)) { - toIEW->commitInfo[tid].emptyROB = true; - } - - wroteToTimeBuffer = true; - changedROBNumEntries[tid] = false; - } - } -} - -template <class Impl> -void -DefaultCommit<Impl>::commitInsts() -{ - //////////////////////////////////// - // Handle commit - // Note that commit will be handled prior to putting new - // instructions in the ROB so that the ROB only tries to commit - // instructions it has in this current cycle, and not instructions - // it is writing in during this cycle. Can't commit and squash - // things at the same time... - //////////////////////////////////// - - DPRINTF(Commit, "Trying to commit instructions in the ROB.\n"); - - unsigned num_committed = 0; - - DynInstPtr head_inst; - - // Commit as many instructions as possible until the commit bandwidth - // limit is reached, or it becomes impossible to commit any more. - while (num_committed < commitWidth) { - int commit_thread = getCommittingThread(); - - if (commit_thread == -1 || !rob->isHeadReady(commit_thread)) - break; - - head_inst = rob->readHeadInst(commit_thread); - - int tid = head_inst->threadNumber; - - assert(tid == commit_thread); - - DPRINTF(Commit, "Trying to commit head instruction, [sn:%i] [tid:%i]\n", - head_inst->seqNum, tid); - - // If the head instruction is squashed, it is ready to retire - // (be removed from the ROB) at any time. - if (head_inst->isSquashed()) { - - DPRINTF(Commit, "Retiring squashed instruction from " - "ROB.\n"); - - rob->retireHead(commit_thread); - - ++commitSquashedInsts; - - // Record that the number of ROB entries has changed. - changedROBNumEntries[tid] = true; - } else { - PC[tid] = head_inst->readPC(); - nextPC[tid] = head_inst->readNextPC(); - - // Increment the total number of non-speculative instructions - // executed. - // Hack for now: it really shouldn't happen until after the - // commit is deemed to be successful, but this count is needed - // for syscalls. - thread[tid]->funcExeInst++; - - // Try to commit the head instruction. - bool commit_success = commitHead(head_inst, num_committed); - - if (commit_success) { - ++num_committed; - - changedROBNumEntries[tid] = true; - - // Set the doneSeqNum to the youngest committed instruction. - toIEW->commitInfo[tid].doneSeqNum = head_inst->seqNum; - - ++commitCommittedInsts; - - // To match the old model, don't count nops and instruction - // prefetches towards the total commit count. - if (!head_inst->isNop() && !head_inst->isInstPrefetch()) { - cpu->instDone(tid); - } - - PC[tid] = nextPC[tid]; - nextPC[tid] = nextPC[tid] + sizeof(TheISA::MachInst); -#if FULL_SYSTEM - int count = 0; - Addr oldpc; - do { - // Debug statement. Checks to make sure we're not - // currently updating state while handling PC events. - if (count == 0) - assert(!thread[tid]->inSyscall && - !thread[tid]->trapPending); - oldpc = PC[tid]; - cpu->system->pcEventQueue.service( - thread[tid]->getXCProxy()); - count++; - } while (oldpc != PC[tid]); - if (count > 1) { - DPRINTF(Commit, "PC skip function event, stopping commit\n"); - break; - } -#endif - } else { - DPRINTF(Commit, "Unable to commit head instruction PC:%#x " - "[tid:%i] [sn:%i].\n", - head_inst->readPC(), tid ,head_inst->seqNum); - break; - } - } - } - - DPRINTF(CommitRate, "%i\n", num_committed); - numCommittedDist.sample(num_committed); - - if (num_committed == commitWidth) { - commitEligible[0]++; - } -} - -template <class Impl> -bool -DefaultCommit<Impl>::commitHead(DynInstPtr &head_inst, unsigned inst_num) -{ - assert(head_inst); - - int tid = head_inst->threadNumber; - - // If the instruction is not executed yet, then it will need extra - // handling. Signal backwards that it should be executed. - if (!head_inst->isExecuted()) { - // Keep this number correct. We have not yet actually executed - // and committed this instruction. - thread[tid]->funcExeInst--; - - head_inst->reachedCommit = true; - - if (head_inst->isNonSpeculative() || - head_inst->isMemBarrier() || - head_inst->isWriteBarrier()) { - - DPRINTF(Commit, "Encountered a barrier or non-speculative " - "instruction [sn:%lli] at the head of the ROB, PC %#x.\n", - head_inst->seqNum, head_inst->readPC()); - -#if !FULL_SYSTEM - // Hack to make sure syscalls/memory barriers/quiesces - // aren't executed until all stores write back their data. - // This direct communication shouldn't be used for - // anything other than this. - if (inst_num > 0 || iewStage->hasStoresToWB()) -#else - if ((head_inst->isMemBarrier() || head_inst->isWriteBarrier() || - head_inst->isQuiesce()) && - iewStage->hasStoresToWB()) -#endif - { - DPRINTF(Commit, "Waiting for all stores to writeback.\n"); - return false; - } - - toIEW->commitInfo[tid].nonSpecSeqNum = head_inst->seqNum; - - // Change the instruction so it won't try to commit again until - // it is executed. - head_inst->clearCanCommit(); - - ++commitNonSpecStalls; - - return false; - } else if (head_inst->isLoad()) { - DPRINTF(Commit, "[sn:%lli]: Uncached load, PC %#x.\n", - head_inst->seqNum, head_inst->readPC()); - - // Send back the non-speculative instruction's sequence - // number. Tell the lsq to re-execute the load. - toIEW->commitInfo[tid].nonSpecSeqNum = head_inst->seqNum; - toIEW->commitInfo[tid].uncached = true; - toIEW->commitInfo[tid].uncachedLoad = head_inst; - - head_inst->clearCanCommit(); - - return false; - } else { - panic("Trying to commit un-executed instruction " - "of unknown type!\n"); - } - } - - if (head_inst->isThreadSync()) { - // Not handled for now. - panic("Thread sync instructions are not handled yet.\n"); - } - - // Stores mark themselves as completed. - if (!head_inst->isStore()) { - head_inst->setCompleted(); - } - - // Use checker prior to updating anything due to traps or PC - // based events. - if (cpu->checker) { - cpu->checker->tick(head_inst); - } - - // Check if the instruction caused a fault. If so, trap. - Fault inst_fault = head_inst->getFault(); - - if (inst_fault != NoFault) { - head_inst->setCompleted(); -#if FULL_SYSTEM - DPRINTF(Commit, "Inst [sn:%lli] PC %#x has a fault\n", - head_inst->seqNum, head_inst->readPC()); - - if (iewStage->hasStoresToWB() || inst_num > 0) { - DPRINTF(Commit, "Stores outstanding, fault must wait.\n"); - return false; - } - - if (cpu->checker && head_inst->isStore()) { - cpu->checker->tick(head_inst); - } - - assert(!thread[tid]->inSyscall); - - // Mark that we're in state update mode so that the trap's - // execution doesn't generate extra squashes. - thread[tid]->inSyscall = true; - - // DTB will sometimes need the machine instruction for when - // faults happen. So we will set it here, prior to the DTB - // possibly needing it for its fault. - thread[tid]->setInst( - static_cast<TheISA::MachInst>(head_inst->staticInst->machInst)); - - // Execute the trap. Although it's slightly unrealistic in - // terms of timing (as it doesn't wait for the full timing of - // the trap event to complete before updating state), it's - // needed to update the state as soon as possible. This - // prevents external agents from changing any specific state - // that the trap need. - cpu->trap(inst_fault, tid); - - // Exit state update mode to avoid accidental updating. - thread[tid]->inSyscall = false; - - commitStatus[tid] = TrapPending; - - // Generate trap squash event. - generateTrapEvent(tid); - - return false; -#else // !FULL_SYSTEM - panic("fault (%d) detected @ PC %08p", inst_fault, - head_inst->PC); -#endif // FULL_SYSTEM - } - - updateComInstStats(head_inst); - - if (head_inst->traceData) { - head_inst->traceData->setFetchSeq(head_inst->seqNum); - head_inst->traceData->setCPSeq(thread[tid]->numInst); - head_inst->traceData->finalize(); - head_inst->traceData = NULL; - } - - // Update the commit rename map - for (int i = 0; i < head_inst->numDestRegs(); i++) { - renameMap[tid]->setEntry(head_inst->destRegIdx(i), - head_inst->renamedDestRegIdx(i)); - } - - // Finally clear the head ROB entry. - rob->retireHead(tid); - - // Return true to indicate that we have committed an instruction. - return true; -} - -template <class Impl> -void -DefaultCommit<Impl>::getInsts() -{ - // Read any renamed instructions and place them into the ROB. - int insts_to_process = min((int)renameWidth, fromRename->size); - - for (int inst_num = 0; inst_num < insts_to_process; ++inst_num) - { - DynInstPtr inst = fromRename->insts[inst_num]; - int tid = inst->threadNumber; - - if (!inst->isSquashed() && - commitStatus[tid] != ROBSquashing) { - changedROBNumEntries[tid] = true; - - DPRINTF(Commit, "Inserting PC %#x [sn:%i] [tid:%i] into ROB.\n", - inst->readPC(), inst->seqNum, tid); - - rob->insertInst(inst); - - assert(rob->getThreadEntries(tid) <= rob->getMaxEntries(tid)); - - youngestSeqNum[tid] = inst->seqNum; - } else { - DPRINTF(Commit, "Instruction PC %#x [sn:%i] [tid:%i] was " - "squashed, skipping.\n", - inst->readPC(), inst->seqNum, tid); - } - } -} - -template <class Impl> -void -DefaultCommit<Impl>::markCompletedInsts() -{ - // Grab completed insts out of the IEW instruction queue, and mark - // instructions completed within the ROB. - for (int inst_num = 0; - inst_num < fromIEW->size && fromIEW->insts[inst_num]; - ++inst_num) - { - if (!fromIEW->insts[inst_num]->isSquashed()) { - DPRINTF(Commit, "[tid:%i]: Marking PC %#x, [sn:%lli] ready " - "within ROB.\n", - fromIEW->insts[inst_num]->threadNumber, - fromIEW->insts[inst_num]->readPC(), - fromIEW->insts[inst_num]->seqNum); - - // Mark the instruction as ready to commit. - fromIEW->insts[inst_num]->setCanCommit(); - } - } -} - -template <class Impl> -bool -DefaultCommit<Impl>::robDoneSquashing() -{ - list<unsigned>::iterator threads = (*activeThreads).begin(); - - while (threads != (*activeThreads).end()) { - unsigned tid = *threads++; - - if (!rob->isDoneSquashing(tid)) - return false; - } - - return true; -} - -template <class Impl> -void -DefaultCommit<Impl>::updateComInstStats(DynInstPtr &inst) -{ - unsigned thread = inst->threadNumber; - - // - // Pick off the software prefetches - // -#ifdef TARGET_ALPHA - if (inst->isDataPrefetch()) { - statComSwp[thread]++; - } else { - statComInst[thread]++; - } -#else - statComInst[thread]++; -#endif - - // - // Control Instructions - // - if (inst->isControl()) - statComBranches[thread]++; - - // - // Memory references - // - if (inst->isMemRef()) { - statComRefs[thread]++; - - if (inst->isLoad()) { - statComLoads[thread]++; - } - } - - if (inst->isMemBarrier()) { - statComMembars[thread]++; - } -} - -//////////////////////////////////////// -// // -// SMT COMMIT POLICY MAINTAINED HERE // -// // -//////////////////////////////////////// -template <class Impl> -int -DefaultCommit<Impl>::getCommittingThread() -{ - if (numThreads > 1) { - switch (commitPolicy) { - - case Aggressive: - //If Policy is Aggressive, commit will call - //this function multiple times per - //cycle - return oldestReady(); - - case RoundRobin: - return roundRobin(); - - case OldestReady: - return oldestReady(); - - default: - return -1; - } - } else { - int tid = (*activeThreads).front(); - - if (commitStatus[tid] == Running || - commitStatus[tid] == Idle || - commitStatus[tid] == FetchTrapPending) { - return tid; - } else { - return -1; - } - } -} - -template<class Impl> -int -DefaultCommit<Impl>::roundRobin() -{ - list<unsigned>::iterator pri_iter = priority_list.begin(); - list<unsigned>::iterator end = priority_list.end(); - - while (pri_iter != end) { - unsigned tid = *pri_iter; - - if (commitStatus[tid] == Running || - commitStatus[tid] == Idle) { - - if (rob->isHeadReady(tid)) { - priority_list.erase(pri_iter); - priority_list.push_back(tid); - - return tid; - } - } - - pri_iter++; - } - - return -1; -} - -template<class Impl> -int -DefaultCommit<Impl>::oldestReady() -{ - unsigned oldest = 0; - bool first = true; - - list<unsigned>::iterator threads = (*activeThreads).begin(); - - while (threads != (*activeThreads).end()) { - unsigned tid = *threads++; - - if (!rob->isEmpty(tid) && - (commitStatus[tid] == Running || - commitStatus[tid] == Idle || - commitStatus[tid] == FetchTrapPending)) { - - if (rob->isHeadReady(tid)) { - - DynInstPtr head_inst = rob->readHeadInst(tid); - - if (first) { - oldest = tid; - first = false; - } else if (head_inst->seqNum < oldest) { - oldest = tid; - } - } - } - } - - if (!first) { - return oldest; - } else { - return -1; - } -} |