src/cpu/base.cc - public/gem5 - Git at Google

 /*
  * Copyright (c) 2011-2012,2016-2017, 2019-2020 ARM Limited
  * All rights reserved
  *
  * The license below extends only to copyright in the software and shall
  * not be construed as granting a license to any other intellectual
  * property including but not limited to intellectual property relating
  * to a hardware implementation of the functionality of the software
  * licensed hereunder.  You may use the software subject to the license
  * terms below provided that you ensure that this notice is replicated
  * unmodified and in its entirety in all distributions of the software,
  * modified or unmodified, in source code or in binary form.
  *
  * Copyright (c) 2002-2005 The Regents of The University of Michigan
  * Copyright (c) 2011 Regents of the University of California
  * Copyright (c) 2013 Advanced Micro Devices, Inc.
  * Copyright (c) 2013 Mark D. Hill and David A. Wood
  * 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 "cpu/base.hh"

 #include <iostream>
 #include <sstream>
 #include <string>

 #include "arch/generic/tlb.hh"
 #include "base/cprintf.hh"
 #include "base/loader/symtab.hh"
 #include "base/logging.hh"
 #include "base/output.hh"
 #include "base/trace.hh"
 #include "cpu/checker/cpu.hh"
 #include "cpu/thread_context.hh"
 #include "debug/Mwait.hh"
 #include "debug/SyscallVerbose.hh"
 #include "debug/Thread.hh"
 #include "mem/page_table.hh"
 #include "params/BaseCPU.hh"
 #include "sim/clocked_object.hh"
 #include "sim/full_system.hh"
 #include "sim/process.hh"
 #include "sim/root.hh"
 #include "sim/sim_events.hh"
 #include "sim/sim_exit.hh"
 #include "sim/system.hh"

 // Hack
 #include "sim/stat_control.hh"

 namespace gem5
 {

 std::unique_ptr<BaseCPU::GlobalStats> BaseCPU::globalStats;

 std::vector<BaseCPU *> BaseCPU::cpuList;

 // This variable reflects the max number of threads in any CPU.  Be
 // careful to only use it once all the CPUs that you care about have
 // been initialized
 int maxThreadsPerCPU = 1;

 CPUProgressEvent::CPUProgressEvent(BaseCPU *_cpu, Tick ival)
     : Event(Event::Progress_Event_Pri), _interval(ival), lastNumInst(0),
       cpu(_cpu), _repeatEvent(true)
 {
     if (_interval)
         cpu->schedule(this, curTick() + _interval);
 }

 void
 CPUProgressEvent::process()
 {
     Counter temp = cpu->totalOps();

     if (_repeatEvent)
       cpu->schedule(this, curTick() + _interval);

     if (cpu->switchedOut()) {
       return;
     }

 #ifndef NDEBUG
     double ipc = double(temp - lastNumInst) / (_interval / cpu->clockPeriod());

     DPRINTFN("%s progress event, total committed:%i, progress insts committed: "
              "%lli, IPC: %0.8d\n", cpu->name(), temp, temp - lastNumInst,
              ipc);
     ipc = 0.0;
 #else
     cprintf("%lli: %s progress event, total committed:%i, progress insts "
             "committed: %lli\n", curTick(), cpu->name(), temp,
             temp - lastNumInst);
 #endif
     lastNumInst = temp;
 }

 const char *
 CPUProgressEvent::description() const
 {
     return "CPU Progress";
 }

 BaseCPU::BaseCPU(const Params &p, bool is_checker)
     : ClockedObject(p), instCnt(0), _cpuId(p.cpu_id), _socketId(p.socket_id),
       _instRequestorId(p.system->getRequestorId(this, "inst")),
       _dataRequestorId(p.system->getRequestorId(this, "data")),
       _taskId(context_switch_task_id::Unknown), _pid(invldPid),
       _switchedOut(p.switched_out), _cacheLineSize(p.system->cacheLineSize()),
       interrupts(p.interrupts), numThreads(p.numThreads), system(p.system),
       previousCycle(0), previousState(CPU_STATE_SLEEP),
       functionTraceStream(nullptr), currentFunctionStart(0),
       currentFunctionEnd(0), functionEntryTick(0),
       baseStats(this),
       addressMonitor(p.numThreads),
       syscallRetryLatency(p.syscallRetryLatency),
       pwrGatingLatency(p.pwr_gating_latency),
       powerGatingOnIdle(p.power_gating_on_idle),
       enterPwrGatingEvent([this]{ enterPwrGating(); }, name())
 {
     // if Python did not provide a valid ID, do it here
     if (_cpuId == -1 ) {
         _cpuId = cpuList.size();
     }

     // add self to global list of CPUs
     cpuList.push_back(this);

     DPRINTF(SyscallVerbose, "Constructing CPU with id %d, socket id %d\n",
                 _cpuId, _socketId);

     if (numThreads > maxThreadsPerCPU)
         maxThreadsPerCPU = numThreads;

     functionTracingEnabled = false;
     if (p.function_trace) {
         const std::string fname = csprintf("ftrace.%s", name());
         functionTraceStream = simout.findOrCreate(fname)->stream();

         currentFunctionStart = currentFunctionEnd = 0;
         functionEntryTick = p.function_trace_start;

         if (p.function_trace_start == 0) {
             functionTracingEnabled = true;
         } else {
             Event *event = new EventFunctionWrapper(
                 [this]{ enableFunctionTrace(); }, name(), true);
             schedule(event, p.function_trace_start);
         }
     }

     tracer = params().tracer;

     if (params().isa.size() != numThreads) {
         fatal("Number of ISAs (%i) assigned to the CPU does not equal number "
               "of threads (%i).\n", params().isa.size(), numThreads);
     }
 }

 void
 BaseCPU::enableFunctionTrace()
 {
     functionTracingEnabled = true;
 }

 BaseCPU::~BaseCPU()
 {
 }

 void
 BaseCPU::postInterrupt(ThreadID tid, int int_num, int index)
 {
     interrupts[tid]->post(int_num, index);
     // Only wake up syscall emulation if it is not waiting on a futex.
     // This is to model the fact that instructions such as ARM SEV
     // should wake up a WFE sleep, but not a futex syscall WAIT. */
     if (FullSystem || !system->futexMap.is_waiting(threadContexts[tid]))
         wakeup(tid);
 }

 void
 BaseCPU::armMonitor(ThreadID tid, Addr address)
 {
     assert(tid < numThreads);
     AddressMonitor &monitor = addressMonitor[tid];

     monitor.armed = true;
     monitor.vAddr = address;
     monitor.pAddr = 0x0;
     DPRINTF(Mwait,"[tid:%d] Armed monitor (vAddr=0x%lx)\n", tid, address);
 }

 bool
 BaseCPU::mwait(ThreadID tid, PacketPtr pkt)
 {
     assert(tid < numThreads);
     AddressMonitor &monitor = addressMonitor[tid];

     if (!monitor.gotWakeup) {
         int block_size = cacheLineSize();
         uint64_t mask = ~((uint64_t)(block_size - 1));

         assert(pkt->req->hasPaddr());
         monitor.pAddr = pkt->getAddr() & mask;
         monitor.waiting = true;

         DPRINTF(Mwait,"[tid:%d] mwait called (vAddr=0x%lx, "
                 "line's paddr=0x%lx)\n", tid, monitor.vAddr, monitor.pAddr);
         return true;
     } else {
         monitor.gotWakeup = false;
         return false;
     }
 }

 void
 BaseCPU::mwaitAtomic(ThreadID tid, ThreadContext *tc, BaseMMU *mmu)
 {
     assert(tid < numThreads);
     AddressMonitor &monitor = addressMonitor[tid];

     RequestPtr req = std::make_shared<Request>();

     Addr addr = monitor.vAddr;
     int block_size = cacheLineSize();
     uint64_t mask = ~((uint64_t)(block_size - 1));
     int size = block_size;

     //The address of the next line if it crosses a cache line boundary.
     Addr secondAddr = roundDown(addr + size - 1, block_size);

     if (secondAddr > addr)
         size = secondAddr - addr;

     req->setVirt(addr, size, 0x0, dataRequestorId(), tc->instAddr());

     // translate to physical address
     Fault fault = mmu->translateAtomic(req, tc, BaseMMU::Read);
     assert(fault == NoFault);

     monitor.pAddr = req->getPaddr() & mask;
     monitor.waiting = true;

     DPRINTF(Mwait,"[tid:%d] mwait called (vAddr=0x%lx, line's paddr=0x%lx)\n",
             tid, monitor.vAddr, monitor.pAddr);
 }

 void
 BaseCPU::init()
 {
     // Set up instruction-count-based termination events, if any. This needs
     // to happen after threadContexts has been constructed.
     if (params().max_insts_any_thread != 0) {
         const char *cause = "a thread reached the max instruction count";
         for (ThreadID tid = 0; tid < numThreads; ++tid)
             scheduleInstStop(tid, params().max_insts_any_thread, cause);
     }

     // Set up instruction-count-based termination events for SimPoints
     // Typically, there are more than one action points.
     // Simulation.py is responsible to take the necessary actions upon
     // exitting the simulation loop.
     if (!params().simpoint_start_insts.empty()) {
         const char *cause = "simpoint starting point found";
         for (size_t i = 0; i < params().simpoint_start_insts.size(); ++i)
             scheduleInstStop(0, params().simpoint_start_insts[i], cause);
     }

     if (params().max_insts_all_threads != 0) {
         const char *cause = "all threads reached the max instruction count";

         // allocate & initialize shared downcounter: each event will
         // decrement this when triggered; simulation will terminate
         // when counter reaches 0
         int *counter = new int;
         *counter = numThreads;
         for (ThreadID tid = 0; tid < numThreads; ++tid) {
             Event *event = new CountedExitEvent(cause, *counter);
             threadContexts[tid]->scheduleInstCountEvent(
                     event, params().max_insts_all_threads);
         }
     }

     if (!params().switched_out) {
         registerThreadContexts();

         verifyMemoryMode();
     }
 }

 void
 BaseCPU::startup()
 {
     if (params().progress_interval) {
         new CPUProgressEvent(this, params().progress_interval);
     }

     if (_switchedOut)
         powerState->set(enums::PwrState::OFF);

     // Assumption CPU start to operate instantaneously without any latency
     if (powerState->get() == enums::PwrState::UNDEFINED)
         powerState->set(enums::PwrState::ON);

 }

 probing::PMUUPtr
 BaseCPU::pmuProbePoint(const char *name)
 {
     probing::PMUUPtr ptr;
     ptr.reset(new probing::PMU(getProbeManager(), name));

     return ptr;
 }

 void
 BaseCPU::regProbePoints()
 {
     ppAllCycles = pmuProbePoint("Cycles");
     ppActiveCycles = pmuProbePoint("ActiveCycles");

     ppRetiredInsts = pmuProbePoint("RetiredInsts");
     ppRetiredInstsPC = pmuProbePoint("RetiredInstsPC");
     ppRetiredLoads = pmuProbePoint("RetiredLoads");
     ppRetiredStores = pmuProbePoint("RetiredStores");
     ppRetiredBranches = pmuProbePoint("RetiredBranches");

     ppSleeping = new ProbePointArg<bool>(this->getProbeManager(),
                                          "Sleeping");
 }

 void
 BaseCPU::probeInstCommit(const StaticInstPtr &inst, Addr pc)
 {
     if (!inst->isMicroop() || inst->isLastMicroop()) {
         ppRetiredInsts->notify(1);
         ppRetiredInstsPC->notify(pc);
     }

     if (inst->isLoad())
         ppRetiredLoads->notify(1);

     if (inst->isStore() || inst->isAtomic())
         ppRetiredStores->notify(1);

     if (inst->isControl())
         ppRetiredBranches->notify(1);
 }

 BaseCPU::
 BaseCPUStats::BaseCPUStats(statistics::Group *parent)
     : statistics::Group(parent),
       ADD_STAT(numCycles, statistics::units::Cycle::get(),
                "Number of cpu cycles simulated"),
       ADD_STAT(numWorkItemsStarted, statistics::units::Count::get(),
                "Number of work items this cpu started"),
       ADD_STAT(numWorkItemsCompleted, statistics::units::Count::get(),
                "Number of work items this cpu completed")
 {
 }

 void
 BaseCPU::regStats()
 {
     ClockedObject::regStats();

     if (!globalStats) {
         /* We need to construct the global CPU stat structure here
          * since it needs a pointer to the Root object. */
         globalStats.reset(new GlobalStats(Root::root()));
     }

     using namespace statistics;

     int size = threadContexts.size();
     if (size > 1) {
         for (int i = 0; i < size; ++i) {
             std::stringstream namestr;
             ccprintf(namestr, "%s.ctx%d", name(), i);
             threadContexts[i]->regStats(namestr.str());
         }
     } else if (size == 1)
         threadContexts[0]->regStats(name());
 }

 Port &
 BaseCPU::getPort(const std::string &if_name, PortID idx)
 {
     // Get the right port based on name. This applies to all the
     // subclasses of the base CPU and relies on their implementation
     // of getDataPort and getInstPort.
     if (if_name == "dcache_port")
         return getDataPort();
     else if (if_name == "icache_port")
         return getInstPort();
     else
         return ClockedObject::getPort(if_name, idx);
 }

 void
 BaseCPU::registerThreadContexts()
 {
     assert(system->multiThread || numThreads == 1);

     fatal_if(interrupts.size() != numThreads,
              "CPU %s has %i interrupt controllers, but is expecting one "
              "per thread (%i)\n",
              name(), interrupts.size(), numThreads);

     ThreadID size = threadContexts.size();
     for (ThreadID tid = 0; tid < size; ++tid) {
         ThreadContext *tc = threadContexts[tid];

         if (system->multiThread) {
             system->registerThreadContext(tc);
         } else {
             system->registerThreadContext(tc, _cpuId);
         }

         if (!FullSystem)
             tc->getProcessPtr()->assignThreadContext(tc->contextId());

         interrupts[tid]->setThreadContext(tc);
         tc->getIsaPtr()->setThreadContext(tc);
     }
 }

 void
 BaseCPU::deschedulePowerGatingEvent()
 {
     if (enterPwrGatingEvent.scheduled()){
         deschedule(enterPwrGatingEvent);
     }
 }

 void
 BaseCPU::schedulePowerGatingEvent()
 {
     for (auto tc : threadContexts) {
         if (tc->status() == ThreadContext::Active)
             return;
     }

     if (powerState->get() == enums::PwrState::CLK_GATED &&
         powerGatingOnIdle) {
         assert(!enterPwrGatingEvent.scheduled());
         // Schedule a power gating event when clock gated for the specified
         // amount of time
         schedule(enterPwrGatingEvent, clockEdge(pwrGatingLatency));
     }
 }

 int
 BaseCPU::findContext(ThreadContext *tc)
 {
     ThreadID size = threadContexts.size();
     for (ThreadID tid = 0; tid < size; ++tid) {
         if (tc == threadContexts[tid])
             return tid;
     }
     return 0;
 }

 void
 BaseCPU::activateContext(ThreadID thread_num)
 {
     DPRINTF(Thread, "activate contextId %d\n",
             threadContexts[thread_num]->contextId());
     // Squash enter power gating event while cpu gets activated
     if (enterPwrGatingEvent.scheduled())
         deschedule(enterPwrGatingEvent);
     // For any active thread running, update CPU power state to active (ON)
     powerState->set(enums::PwrState::ON);

     updateCycleCounters(CPU_STATE_WAKEUP);
 }

 void
 BaseCPU::suspendContext(ThreadID thread_num)
 {
     DPRINTF(Thread, "suspend contextId %d\n",
             threadContexts[thread_num]->contextId());
     // Check if all threads are suspended
     for (auto t : threadContexts) {
         if (t->status() != ThreadContext::Suspended) {
             return;
         }
     }

     // All CPU thread are suspended, update cycle count
     updateCycleCounters(CPU_STATE_SLEEP);

     // All CPU threads suspended, enter lower power state for the CPU
     powerState->set(enums::PwrState::CLK_GATED);

     // If pwrGatingLatency is set to 0 then this mechanism is disabled
     if (powerGatingOnIdle) {
         // Schedule power gating event when clock gated for pwrGatingLatency
         // cycles
         schedule(enterPwrGatingEvent, clockEdge(pwrGatingLatency));
     }
 }

 void
 BaseCPU::haltContext(ThreadID thread_num)
 {
     updateCycleCounters(BaseCPU::CPU_STATE_SLEEP);
 }

 void
 BaseCPU::enterPwrGating(void)
 {
     powerState->set(enums::PwrState::OFF);
 }

 void
 BaseCPU::switchOut()
 {
     assert(!_switchedOut);
     _switchedOut = true;

     // Flush all TLBs in the CPU to avoid having stale translations if
     // it gets switched in later.
     flushTLBs();

     // Go to the power gating state
     powerState->set(enums::PwrState::OFF);
 }

 void
 BaseCPU::takeOverFrom(BaseCPU *oldCPU)
 {
     assert(threadContexts.size() == oldCPU->threadContexts.size());
     assert(_cpuId == oldCPU->cpuId());
     assert(_switchedOut);
     assert(oldCPU != this);
     _pid = oldCPU->getPid();
     _taskId = oldCPU->taskId();
     // Take over the power state of the switchedOut CPU
     powerState->set(oldCPU->powerState->get());

     previousState = oldCPU->previousState;
     previousCycle = oldCPU->previousCycle;

     _switchedOut = false;

     ThreadID size = threadContexts.size();
     for (ThreadID i = 0; i < size; ++i) {
         ThreadContext *newTC = threadContexts[i];
         ThreadContext *oldTC = oldCPU->threadContexts[i];

         newTC->getIsaPtr()->setThreadContext(newTC);

         newTC->takeOverFrom(oldTC);

         assert(newTC->contextId() == oldTC->contextId());
         assert(newTC->threadId() == oldTC->threadId());
         system->replaceThreadContext(newTC, newTC->contextId());

         /* This code no longer works since the zero register (e.g.,
          * r31 on Alpha) doesn't necessarily contain zero at this
          * point.
            if (debug::Context)
             ThreadContext::compare(oldTC, newTC);
         */

         newTC->getMMUPtr()->takeOverFrom(oldTC->getMMUPtr());

         // Checker whether or not we have to transfer CheckerCPU
         // objects over in the switch
         CheckerCPU *old_checker = oldTC->getCheckerCpuPtr();
         CheckerCPU *new_checker = newTC->getCheckerCpuPtr();
         if (old_checker && new_checker) {
             new_checker->getMMUPtr()->takeOverFrom(old_checker->getMMUPtr());
         }
     }

     interrupts = oldCPU->interrupts;
     for (ThreadID tid = 0; tid < numThreads; tid++) {
         interrupts[tid]->setThreadContext(threadContexts[tid]);
     }
     oldCPU->interrupts.clear();

     // All CPUs have an instruction and a data port, and the new CPU's
     // ports are dangling while the old CPU has its ports connected
     // already. Unbind the old CPU and then bind the ports of the one
     // we are switching to.
     getInstPort().takeOverFrom(&oldCPU->getInstPort());
     getDataPort().takeOverFrom(&oldCPU->getDataPort());
 }

 void
 BaseCPU::flushTLBs()
 {
     for (ThreadID i = 0; i < threadContexts.size(); ++i) {
         ThreadContext &tc(*threadContexts[i]);
         CheckerCPU *checker(tc.getCheckerCpuPtr());

         tc.getMMUPtr()->flushAll();
         if (checker) {
             checker->getMMUPtr()->flushAll();
         }
     }
 }

 void
 BaseCPU::serialize(CheckpointOut &cp) const
 {
     SERIALIZE_SCALAR(instCnt);

     if (!_switchedOut) {
         /* Unlike _pid, _taskId is not serialized, as they are dynamically
          * assigned unique ids that are only meaningful for the duration of
          * a specific run. We will need to serialize the entire taskMap in
          * system. */
         SERIALIZE_SCALAR(_pid);

         // Serialize the threads, this is done by the CPU implementation.
         for (ThreadID i = 0; i < numThreads; ++i) {
             ScopedCheckpointSection sec(cp, csprintf("xc.%i", i));
             interrupts[i]->serialize(cp);
             serializeThread(cp, i);
         }
     }
 }

 void
 BaseCPU::unserialize(CheckpointIn &cp)
 {
     UNSERIALIZE_SCALAR(instCnt);

     if (!_switchedOut) {
         UNSERIALIZE_SCALAR(_pid);

         // Unserialize the threads, this is done by the CPU implementation.
         for (ThreadID i = 0; i < numThreads; ++i) {
             ScopedCheckpointSection sec(cp, csprintf("xc.%i", i));
             interrupts[i]->unserialize(cp);
             unserializeThread(cp, i);
         }
     }
 }

 void
 BaseCPU::scheduleInstStop(ThreadID tid, Counter insts, const char *cause)
 {
     const Tick now(getCurrentInstCount(tid));
     Event *event(new LocalSimLoopExitEvent(cause, 0));

     threadContexts[tid]->scheduleInstCountEvent(event, now + insts);
 }

 Tick
 BaseCPU::getCurrentInstCount(ThreadID tid)
 {
     return threadContexts[tid]->getCurrentInstCount();
 }

 AddressMonitor::AddressMonitor() {
     armed = false;
     waiting = false;
     gotWakeup = false;
 }

 bool AddressMonitor::doMonitor(PacketPtr pkt) {
     assert(pkt->req->hasPaddr());
     if (armed && waiting) {
         if (pAddr == pkt->getAddr()) {
             DPRINTF(Mwait,"pAddr=0x%lx invalidated: waking up core\n",
                     pkt->getAddr());
             waiting = false;
             return true;
         }
     }
     return false;
 }


 void
 BaseCPU::traceFunctionsInternal(Addr pc)
 {
     if (loader::debugSymbolTable.empty())
         return;

     // if pc enters different function, print new function symbol and
     // update saved range.  Otherwise do nothing.
     if (pc < currentFunctionStart || pc >= currentFunctionEnd) {
         auto it = loader::debugSymbolTable.findNearest(
                 pc, currentFunctionEnd);

         std::string sym_str;
         if (it == loader::debugSymbolTable.end()) {
             // no symbol found: use addr as label
             sym_str = csprintf("%#x", pc);
             currentFunctionStart = pc;
             currentFunctionEnd = pc + 1;
         } else {
             sym_str = it->name;
             currentFunctionStart = it->address;
         }

         ccprintf(*functionTraceStream, " (%d)\n%d: %s",
                  curTick() - functionEntryTick, curTick(), sym_str);
         functionEntryTick = curTick();
     }
 }


 BaseCPU::GlobalStats::GlobalStats(statistics::Group *parent)
     : statistics::Group(parent),
     ADD_STAT(simInsts, statistics::units::Count::get(),
              "Number of instructions simulated"),
     ADD_STAT(simOps, statistics::units::Count::get(),
              "Number of ops (including micro ops) simulated"),
     ADD_STAT(hostInstRate, statistics::units::Rate<
                 statistics::units::Count, statistics::units::Second>::get(),
              "Simulator instruction rate (inst/s)"),
     ADD_STAT(hostOpRate, statistics::units::Rate<
                 statistics::units::Count, statistics::units::Second>::get(),
              "Simulator op (including micro ops) rate (op/s)")
 {
     simInsts
         .functor(BaseCPU::numSimulatedInsts)
         .precision(0)
         .prereq(simInsts)
         ;

     simOps
         .functor(BaseCPU::numSimulatedOps)
         .precision(0)
         .prereq(simOps)
         ;

     hostInstRate
         .precision(0)
         .prereq(simInsts)
         ;

     hostOpRate
         .precision(0)
         .prereq(simOps)
         ;

     hostInstRate = simInsts / hostSeconds;
     hostOpRate = simOps / hostSeconds;
 }

 } // namespace gem5
	/*
	* Copyright (c) 2011-2012,2016-2017, 2019-2020 ARM Limited
	* All rights reserved
	*
	* The license below extends only to copyright in the software and shall
	* not be construed as granting a license to any other intellectual
	* property including but not limited to intellectual property relating
	* to a hardware implementation of the functionality of the software
	* licensed hereunder. You may use the software subject to the license
	* terms below provided that you ensure that this notice is replicated
	* unmodified and in its entirety in all distributions of the software,
	* modified or unmodified, in source code or in binary form.
	*
	* Copyright (c) 2002-2005 The Regents of The University of Michigan
	* Copyright (c) 2011 Regents of the University of California
	* Copyright (c) 2013 Advanced Micro Devices, Inc.
	* Copyright (c) 2013 Mark D. Hill and David A. Wood
	* 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 "cpu/base.hh"

	#include <iostream>
	#include <sstream>
	#include <string>

	#include "arch/generic/tlb.hh"
	#include "base/cprintf.hh"
	#include "base/loader/symtab.hh"
	#include "base/logging.hh"
	#include "base/output.hh"
	#include "base/trace.hh"
	#include "cpu/checker/cpu.hh"
	#include "cpu/thread_context.hh"
	#include "debug/Mwait.hh"
	#include "debug/SyscallVerbose.hh"
	#include "debug/Thread.hh"
	#include "mem/page_table.hh"
	#include "params/BaseCPU.hh"
	#include "sim/clocked_object.hh"
	#include "sim/full_system.hh"
	#include "sim/process.hh"
	#include "sim/root.hh"
	#include "sim/sim_events.hh"
	#include "sim/sim_exit.hh"
	#include "sim/system.hh"

	// Hack
	#include "sim/stat_control.hh"

	namespace gem5
	{

	std::unique_ptr<BaseCPU::GlobalStats> BaseCPU::globalStats;

	std::vector<BaseCPU *> BaseCPU::cpuList;

	// This variable reflects the max number of threads in any CPU. Be
	// careful to only use it once all the CPUs that you care about have
	// been initialized
	int maxThreadsPerCPU = 1;

	CPUProgressEvent::CPUProgressEvent(BaseCPU *_cpu, Tick ival)
	: Event(Event::Progress_Event_Pri), _interval(ival), lastNumInst(0),
	cpu(_cpu), _repeatEvent(true)
	{
	if (_interval)
	cpu->schedule(this, curTick() + _interval);
	}

	void
	CPUProgressEvent::process()
	{
	Counter temp = cpu->totalOps();

	if (_repeatEvent)
	cpu->schedule(this, curTick() + _interval);

	if (cpu->switchedOut()) {
	return;
	}

	#ifndef NDEBUG
	double ipc = double(temp - lastNumInst) / (_interval / cpu->clockPeriod());

	DPRINTFN("%s progress event, total committed:%i, progress insts committed: "
	"%lli, IPC: %0.8d\n", cpu->name(), temp, temp - lastNumInst,
	ipc);
	ipc = 0.0;
	#else
	cprintf("%lli: %s progress event, total committed:%i, progress insts "
	"committed: %lli\n", curTick(), cpu->name(), temp,
	temp - lastNumInst);
	#endif
	lastNumInst = temp;
	}

	const char *
	CPUProgressEvent::description() const
	{
	return "CPU Progress";
	}

	BaseCPU::BaseCPU(const Params &p, bool is_checker)
	: ClockedObject(p), instCnt(0), _cpuId(p.cpu_id), _socketId(p.socket_id),
	_instRequestorId(p.system->getRequestorId(this, "inst")),
	_dataRequestorId(p.system->getRequestorId(this, "data")),
	_taskId(context_switch_task_id::Unknown), _pid(invldPid),
	_switchedOut(p.switched_out), _cacheLineSize(p.system->cacheLineSize()),
	interrupts(p.interrupts), numThreads(p.numThreads), system(p.system),
	previousCycle(0), previousState(CPU_STATE_SLEEP),
	functionTraceStream(nullptr), currentFunctionStart(0),
	currentFunctionEnd(0), functionEntryTick(0),
	baseStats(this),
	addressMonitor(p.numThreads),
	syscallRetryLatency(p.syscallRetryLatency),
	pwrGatingLatency(p.pwr_gating_latency),
	powerGatingOnIdle(p.power_gating_on_idle),
	enterPwrGatingEvent([this]{ enterPwrGating(); }, name())
	{
	// if Python did not provide a valid ID, do it here
	if (_cpuId == -1 ) {
	_cpuId = cpuList.size();
	}

	// add self to global list of CPUs
	cpuList.push_back(this);

	DPRINTF(SyscallVerbose, "Constructing CPU with id %d, socket id %d\n",
	_cpuId, _socketId);

	if (numThreads > maxThreadsPerCPU)
	maxThreadsPerCPU = numThreads;

	functionTracingEnabled = false;
	if (p.function_trace) {
	const std::string fname = csprintf("ftrace.%s", name());
	functionTraceStream = simout.findOrCreate(fname)->stream();

	currentFunctionStart = currentFunctionEnd = 0;
	functionEntryTick = p.function_trace_start;

	if (p.function_trace_start == 0) {
	functionTracingEnabled = true;
	} else {
	Event *event = new EventFunctionWrapper(
	[this]{ enableFunctionTrace(); }, name(), true);
	schedule(event, p.function_trace_start);
	}
	}

	tracer = params().tracer;

	if (params().isa.size() != numThreads) {
	fatal("Number of ISAs (%i) assigned to the CPU does not equal number "
	"of threads (%i).\n", params().isa.size(), numThreads);
	}
	}

	void
	BaseCPU::enableFunctionTrace()
	{
	functionTracingEnabled = true;
	}

	BaseCPU::~BaseCPU()
	{
	}

	void
	BaseCPU::postInterrupt(ThreadID tid, int int_num, int index)
	{
	interrupts[tid]->post(int_num, index);
	// Only wake up syscall emulation if it is not waiting on a futex.
	// This is to model the fact that instructions such as ARM SEV
	// should wake up a WFE sleep, but not a futex syscall WAIT. */
	if (FullSystem \|\| !system->futexMap.is_waiting(threadContexts[tid]))
	wakeup(tid);
	}

	void
	BaseCPU::armMonitor(ThreadID tid, Addr address)
	{
	assert(tid < numThreads);
	AddressMonitor &monitor = addressMonitor[tid];

	monitor.armed = true;
	monitor.vAddr = address;
	monitor.pAddr = 0x0;
	DPRINTF(Mwait,"[tid:%d] Armed monitor (vAddr=0x%lx)\n", tid, address);
	}

	bool
	BaseCPU::mwait(ThreadID tid, PacketPtr pkt)
	{
	assert(tid < numThreads);
	AddressMonitor &monitor = addressMonitor[tid];

	if (!monitor.gotWakeup) {
	int block_size = cacheLineSize();
	uint64_t mask = ~((uint64_t)(block_size - 1));

	assert(pkt->req->hasPaddr());
	monitor.pAddr = pkt->getAddr() & mask;
	monitor.waiting = true;

	DPRINTF(Mwait,"[tid:%d] mwait called (vAddr=0x%lx, "
	"line's paddr=0x%lx)\n", tid, monitor.vAddr, monitor.pAddr);
	return true;
	} else {
	monitor.gotWakeup = false;
	return false;
	}
	}

	void
	BaseCPU::mwaitAtomic(ThreadID tid, ThreadContext tc, BaseMMU mmu)
	{
	assert(tid < numThreads);
	AddressMonitor &monitor = addressMonitor[tid];

	RequestPtr req = std::make_shared<Request>();

	Addr addr = monitor.vAddr;
	int block_size = cacheLineSize();
	uint64_t mask = ~((uint64_t)(block_size - 1));
	int size = block_size;

	//The address of the next line if it crosses a cache line boundary.
	Addr secondAddr = roundDown(addr + size - 1, block_size);

	if (secondAddr > addr)
	size = secondAddr - addr;

	req->setVirt(addr, size, 0x0, dataRequestorId(), tc->instAddr());

	// translate to physical address
	Fault fault = mmu->translateAtomic(req, tc, BaseMMU::Read);
	assert(fault == NoFault);

	monitor.pAddr = req->getPaddr() & mask;
	monitor.waiting = true;

	DPRINTF(Mwait,"[tid:%d] mwait called (vAddr=0x%lx, line's paddr=0x%lx)\n",
	tid, monitor.vAddr, monitor.pAddr);
	}

	void
	BaseCPU::init()
	{
	// Set up instruction-count-based termination events, if any. This needs
	// to happen after threadContexts has been constructed.
	if (params().max_insts_any_thread != 0) {
	const char *cause = "a thread reached the max instruction count";
	for (ThreadID tid = 0; tid < numThreads; ++tid)
	scheduleInstStop(tid, params().max_insts_any_thread, cause);
	}

	// Set up instruction-count-based termination events for SimPoints
	// Typically, there are more than one action points.
	// Simulation.py is responsible to take the necessary actions upon
	// exitting the simulation loop.
	if (!params().simpoint_start_insts.empty()) {
	const char *cause = "simpoint starting point found";
	for (size_t i = 0; i < params().simpoint_start_insts.size(); ++i)
	scheduleInstStop(0, params().simpoint_start_insts[i], cause);
	}

	if (params().max_insts_all_threads != 0) {
	const char *cause = "all threads reached the max instruction count";

	// allocate & initialize shared downcounter: each event will
	// decrement this when triggered; simulation will terminate
	// when counter reaches 0
	int *counter = new int;
	*counter = numThreads;
	for (ThreadID tid = 0; tid < numThreads; ++tid) {
	Event event = new CountedExitEvent(cause, counter);
	threadContexts[tid]->scheduleInstCountEvent(
	event, params().max_insts_all_threads);
	}
	}

	if (!params().switched_out) {
	registerThreadContexts();

	verifyMemoryMode();
	}
	}

	void
	BaseCPU::startup()
	{
	if (params().progress_interval) {
	new CPUProgressEvent(this, params().progress_interval);
	}

	if (_switchedOut)
	powerState->set(enums::PwrState::OFF);

	// Assumption CPU start to operate instantaneously without any latency
	if (powerState->get() == enums::PwrState::UNDEFINED)
	powerState->set(enums::PwrState::ON);

	}

	probing::PMUUPtr
	BaseCPU::pmuProbePoint(const char *name)
	{
	probing::PMUUPtr ptr;
	ptr.reset(new probing::PMU(getProbeManager(), name));

	return ptr;
	}

	void
	BaseCPU::regProbePoints()
	{
	ppAllCycles = pmuProbePoint("Cycles");
	ppActiveCycles = pmuProbePoint("ActiveCycles");

	ppRetiredInsts = pmuProbePoint("RetiredInsts");
	ppRetiredInstsPC = pmuProbePoint("RetiredInstsPC");
	ppRetiredLoads = pmuProbePoint("RetiredLoads");
	ppRetiredStores = pmuProbePoint("RetiredStores");
	ppRetiredBranches = pmuProbePoint("RetiredBranches");

	ppSleeping = new ProbePointArg<bool>(this->getProbeManager(),
	"Sleeping");
	}

	void
	BaseCPU::probeInstCommit(const StaticInstPtr &inst, Addr pc)
	{
	if (!inst->isMicroop() \|\| inst->isLastMicroop()) {
	ppRetiredInsts->notify(1);
	ppRetiredInstsPC->notify(pc);
	}

	if (inst->isLoad())
	ppRetiredLoads->notify(1);

	if (inst->isStore() \|\| inst->isAtomic())
	ppRetiredStores->notify(1);

	if (inst->isControl())
	ppRetiredBranches->notify(1);
	}

	BaseCPU::
	BaseCPUStats::BaseCPUStats(statistics::Group *parent)
	: statistics::Group(parent),
	ADD_STAT(numCycles, statistics::units::Cycle::get(),
	"Number of cpu cycles simulated"),
	ADD_STAT(numWorkItemsStarted, statistics::units::Count::get(),
	"Number of work items this cpu started"),
	ADD_STAT(numWorkItemsCompleted, statistics::units::Count::get(),
	"Number of work items this cpu completed")
	{
	}

	void
	BaseCPU::regStats()
	{
	ClockedObject::regStats();

	if (!globalStats) {
	/* We need to construct the global CPU stat structure here
	* since it needs a pointer to the Root object. */
	globalStats.reset(new GlobalStats(Root::root()));
	}

	using namespace statistics;

	int size = threadContexts.size();
	if (size > 1) {
	for (int i = 0; i < size; ++i) {
	std::stringstream namestr;
	ccprintf(namestr, "%s.ctx%d", name(), i);
	threadContexts[i]->regStats(namestr.str());
	}
	} else if (size == 1)
	threadContexts[0]->regStats(name());
	}

	Port &
	BaseCPU::getPort(const std::string &if_name, PortID idx)
	{
	// Get the right port based on name. This applies to all the
	// subclasses of the base CPU and relies on their implementation
	// of getDataPort and getInstPort.
	if (if_name == "dcache_port")
	return getDataPort();
	else if (if_name == "icache_port")
	return getInstPort();
	else
	return ClockedObject::getPort(if_name, idx);
	}

	void
	BaseCPU::registerThreadContexts()
	{
	assert(system->multiThread \|\| numThreads == 1);

	fatal_if(interrupts.size() != numThreads,
	"CPU %s has %i interrupt controllers, but is expecting one "
	"per thread (%i)\n",
	name(), interrupts.size(), numThreads);

	ThreadID size = threadContexts.size();
	for (ThreadID tid = 0; tid < size; ++tid) {
	ThreadContext *tc = threadContexts[tid];

	if (system->multiThread) {
	system->registerThreadContext(tc);
	} else {
	system->registerThreadContext(tc, _cpuId);
	}

	if (!FullSystem)
	tc->getProcessPtr()->assignThreadContext(tc->contextId());

	interrupts[tid]->setThreadContext(tc);
	tc->getIsaPtr()->setThreadContext(tc);
	}
	}

	void
	BaseCPU::deschedulePowerGatingEvent()
	{
	if (enterPwrGatingEvent.scheduled()){
	deschedule(enterPwrGatingEvent);
	}
	}

	void
	BaseCPU::schedulePowerGatingEvent()
	{
	for (auto tc : threadContexts) {
	if (tc->status() == ThreadContext::Active)
	return;
	}

	if (powerState->get() == enums::PwrState::CLK_GATED &&
	powerGatingOnIdle) {
	assert(!enterPwrGatingEvent.scheduled());
	// Schedule a power gating event when clock gated for the specified
	// amount of time
	schedule(enterPwrGatingEvent, clockEdge(pwrGatingLatency));
	}
	}

	int
	BaseCPU::findContext(ThreadContext *tc)
	{
	ThreadID size = threadContexts.size();
	for (ThreadID tid = 0; tid < size; ++tid) {
	if (tc == threadContexts[tid])
	return tid;
	}
	return 0;
	}

	void
	BaseCPU::activateContext(ThreadID thread_num)
	{
	DPRINTF(Thread, "activate contextId %d\n",
	threadContexts[thread_num]->contextId());
	// Squash enter power gating event while cpu gets activated
	if (enterPwrGatingEvent.scheduled())
	deschedule(enterPwrGatingEvent);
	// For any active thread running, update CPU power state to active (ON)
	powerState->set(enums::PwrState::ON);

	updateCycleCounters(CPU_STATE_WAKEUP);
	}

	void
	BaseCPU::suspendContext(ThreadID thread_num)
	{
	DPRINTF(Thread, "suspend contextId %d\n",
	threadContexts[thread_num]->contextId());
	// Check if all threads are suspended
	for (auto t : threadContexts) {
	if (t->status() != ThreadContext::Suspended) {
	return;
	}
	}

	// All CPU thread are suspended, update cycle count
	updateCycleCounters(CPU_STATE_SLEEP);

	// All CPU threads suspended, enter lower power state for the CPU
	powerState->set(enums::PwrState::CLK_GATED);

	// If pwrGatingLatency is set to 0 then this mechanism is disabled
	if (powerGatingOnIdle) {
	// Schedule power gating event when clock gated for pwrGatingLatency
	// cycles
	schedule(enterPwrGatingEvent, clockEdge(pwrGatingLatency));
	}
	}

	void
	BaseCPU::haltContext(ThreadID thread_num)
	{
	updateCycleCounters(BaseCPU::CPU_STATE_SLEEP);
	}

	void
	BaseCPU::enterPwrGating(void)
	{
	powerState->set(enums::PwrState::OFF);
	}

	void
	BaseCPU::switchOut()
	{
	assert(!_switchedOut);
	_switchedOut = true;

	// Flush all TLBs in the CPU to avoid having stale translations if
	// it gets switched in later.
	flushTLBs();

	// Go to the power gating state
	powerState->set(enums::PwrState::OFF);
	}

	void
	BaseCPU::takeOverFrom(BaseCPU *oldCPU)
	{
	assert(threadContexts.size() == oldCPU->threadContexts.size());
	assert(_cpuId == oldCPU->cpuId());
	assert(_switchedOut);
	assert(oldCPU != this);
	_pid = oldCPU->getPid();
	_taskId = oldCPU->taskId();
	// Take over the power state of the switchedOut CPU
	powerState->set(oldCPU->powerState->get());

	previousState = oldCPU->previousState;
	previousCycle = oldCPU->previousCycle;

	_switchedOut = false;

	ThreadID size = threadContexts.size();
	for (ThreadID i = 0; i < size; ++i) {
	ThreadContext *newTC = threadContexts[i];
	ThreadContext *oldTC = oldCPU->threadContexts[i];

	newTC->getIsaPtr()->setThreadContext(newTC);

	newTC->takeOverFrom(oldTC);

	assert(newTC->contextId() == oldTC->contextId());
	assert(newTC->threadId() == oldTC->threadId());
	system->replaceThreadContext(newTC, newTC->contextId());

	/* This code no longer works since the zero register (e.g.,
	* r31 on Alpha) doesn't necessarily contain zero at this
	* point.
	if (debug::Context)
	ThreadContext::compare(oldTC, newTC);
	*/

	newTC->getMMUPtr()->takeOverFrom(oldTC->getMMUPtr());

	// Checker whether or not we have to transfer CheckerCPU
	// objects over in the switch
	CheckerCPU *old_checker = oldTC->getCheckerCpuPtr();
	CheckerCPU *new_checker = newTC->getCheckerCpuPtr();
	if (old_checker && new_checker) {
	new_checker->getMMUPtr()->takeOverFrom(old_checker->getMMUPtr());
	}
	}

	interrupts = oldCPU->interrupts;
	for (ThreadID tid = 0; tid < numThreads; tid++) {
	interrupts[tid]->setThreadContext(threadContexts[tid]);
	}
	oldCPU->interrupts.clear();

	// All CPUs have an instruction and a data port, and the new CPU's
	// ports are dangling while the old CPU has its ports connected
	// already. Unbind the old CPU and then bind the ports of the one
	// we are switching to.
	getInstPort().takeOverFrom(&oldCPU->getInstPort());
	getDataPort().takeOverFrom(&oldCPU->getDataPort());
	}

	void
	BaseCPU::flushTLBs()
	{
	for (ThreadID i = 0; i < threadContexts.size(); ++i) {
	ThreadContext &tc(*threadContexts[i]);
	CheckerCPU *checker(tc.getCheckerCpuPtr());

	tc.getMMUPtr()->flushAll();
	if (checker) {
	checker->getMMUPtr()->flushAll();
	}
	}
	}

	void
	BaseCPU::serialize(CheckpointOut &cp) const
	{
	SERIALIZE_SCALAR(instCnt);

	if (!_switchedOut) {
	/* Unlike _pid, _taskId is not serialized, as they are dynamically
	* assigned unique ids that are only meaningful for the duration of
	* a specific run. We will need to serialize the entire taskMap in
	* system. */
	SERIALIZE_SCALAR(_pid);

	// Serialize the threads, this is done by the CPU implementation.
	for (ThreadID i = 0; i < numThreads; ++i) {
	ScopedCheckpointSection sec(cp, csprintf("xc.%i", i));
	interrupts[i]->serialize(cp);
	serializeThread(cp, i);
	}
	}
	}

	void
	BaseCPU::unserialize(CheckpointIn &cp)
	{
	UNSERIALIZE_SCALAR(instCnt);

	if (!_switchedOut) {
	UNSERIALIZE_SCALAR(_pid);

	// Unserialize the threads, this is done by the CPU implementation.
	for (ThreadID i = 0; i < numThreads; ++i) {
	ScopedCheckpointSection sec(cp, csprintf("xc.%i", i));
	interrupts[i]->unserialize(cp);
	unserializeThread(cp, i);
	}
	}
	}

	void
	BaseCPU::scheduleInstStop(ThreadID tid, Counter insts, const char *cause)
	{
	const Tick now(getCurrentInstCount(tid));
	Event *event(new LocalSimLoopExitEvent(cause, 0));

	threadContexts[tid]->scheduleInstCountEvent(event, now + insts);
	}

	Tick
	BaseCPU::getCurrentInstCount(ThreadID tid)
	{
	return threadContexts[tid]->getCurrentInstCount();
	}

	AddressMonitor::AddressMonitor() {
	armed = false;
	waiting = false;
	gotWakeup = false;
	}

	bool AddressMonitor::doMonitor(PacketPtr pkt) {
	assert(pkt->req->hasPaddr());
	if (armed && waiting) {
	if (pAddr == pkt->getAddr()) {
	DPRINTF(Mwait,"pAddr=0x%lx invalidated: waking up core\n",
	pkt->getAddr());
	waiting = false;
	return true;
	}
	}
	return false;
	}


	void
	BaseCPU::traceFunctionsInternal(Addr pc)
	{
	if (loader::debugSymbolTable.empty())
	return;

	// if pc enters different function, print new function symbol and
	// update saved range. Otherwise do nothing.
	if (pc < currentFunctionStart \|\| pc >= currentFunctionEnd) {
	auto it = loader::debugSymbolTable.findNearest(
	pc, currentFunctionEnd);

	std::string sym_str;
	if (it == loader::debugSymbolTable.end()) {
	// no symbol found: use addr as label
	sym_str = csprintf("%#x", pc);
	currentFunctionStart = pc;
	currentFunctionEnd = pc + 1;
	} else {
	sym_str = it->name;
	currentFunctionStart = it->address;
	}

	ccprintf(*functionTraceStream, " (%d)\n%d: %s",
	curTick() - functionEntryTick, curTick(), sym_str);
	functionEntryTick = curTick();
	}
	}


	BaseCPU::GlobalStats::GlobalStats(statistics::Group *parent)
	: statistics::Group(parent),
	ADD_STAT(simInsts, statistics::units::Count::get(),
	"Number of instructions simulated"),
	ADD_STAT(simOps, statistics::units::Count::get(),
	"Number of ops (including micro ops) simulated"),
	ADD_STAT(hostInstRate, statistics::units::Rate<
	statistics::units::Count, statistics::units::Second>::get(),
	"Simulator instruction rate (inst/s)"),
	ADD_STAT(hostOpRate, statistics::units::Rate<
	statistics::units::Count, statistics::units::Second>::get(),
	"Simulator op (including micro ops) rate (op/s)")
	{
	simInsts
	.functor(BaseCPU::numSimulatedInsts)
	.precision(0)
	.prereq(simInsts)
	;

	simOps
	.functor(BaseCPU::numSimulatedOps)
	.precision(0)
	.prereq(simOps)
	;

	hostInstRate
	.precision(0)
	.prereq(simInsts)
	;

	hostOpRate
	.precision(0)
	.prereq(simOps)
	;

	hostInstRate = simInsts / hostSeconds;
	hostOpRate = simOps / hostSeconds;
	}

	} // namespace gem5