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gem5/src/cpu/o3/cpu.cc
Andreas Sandberg 1814a85a05 cpu: Rewrite O3 draining to avoid stopping in microcode 
Previously, the O3 CPU could stop in the middle of a microcode
sequence. This patch makes sure that the pipeline stops when it has
committed a normal instruction or exited from a microcode
sequence. Additionally, it makes sure that the pipeline has no
instructions in flight when it is drained, which should make draining
more robust.

Draining is controlled in the commit stage, which checks if the next
PC after a committed instruction is in microcode. If this isn't the
case, it requests a squash of all instructions after that the
instruction that just committed and immediately signals a drain stall
to the fetch stage. The CPU then continues to execute until the
pipeline and all associated buffers are empty.
2013-01-07 13:05:46 -05:00

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/*
* Copyright (c) 2011-2012 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) 2004-2006 The Regents of The University of Michigan
* Copyright (c) 2011 Regents of the University of California
* 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
* Rick Strong
*/
#include "arch/kernel_stats.hh"
#include "config/the_isa.hh"
#include "cpu/checker/cpu.hh"
#include "cpu/checker/thread_context.hh"
#include "cpu/o3/cpu.hh"
#include "cpu/o3/isa_specific.hh"
#include "cpu/o3/thread_context.hh"
#include "cpu/activity.hh"
#include "cpu/quiesce_event.hh"
#include "cpu/simple_thread.hh"
#include "cpu/thread_context.hh"
#include "debug/Activity.hh"
#include "debug/Drain.hh"
#include "debug/O3CPU.hh"
#include "debug/Quiesce.hh"
#include "enums/MemoryMode.hh"
#include "sim/core.hh"
#include "sim/full_system.hh"
#include "sim/process.hh"
#include "sim/stat_control.hh"
#include "sim/system.hh"
#if THE_ISA == ALPHA_ISA
#include "arch/alpha/osfpal.hh"
#include "debug/Activity.hh"
#endif
struct BaseCPUParams;
using namespace TheISA;
using namespace std;
BaseO3CPU::BaseO3CPU(BaseCPUParams *params)
: BaseCPU(params)
{
}
void
BaseO3CPU::regStats()
{
BaseCPU::regStats();
}
template<class Impl>
bool
FullO3CPU<Impl>::IcachePort::recvTimingResp(PacketPtr pkt)
{
DPRINTF(O3CPU, "Fetch unit received timing\n");
// We shouldn't ever get a block in ownership state
assert(!(pkt->memInhibitAsserted() && !pkt->sharedAsserted()));
fetch->processCacheCompletion(pkt);
return true;
}
template<class Impl>
void
FullO3CPU<Impl>::IcachePort::recvRetry()
{
fetch->recvRetry();
}
template <class Impl>
bool
FullO3CPU<Impl>::DcachePort::recvTimingResp(PacketPtr pkt)
{
return lsq->recvTimingResp(pkt);
}
template <class Impl>
void
FullO3CPU<Impl>::DcachePort::recvTimingSnoopReq(PacketPtr pkt)
{
lsq->recvTimingSnoopReq(pkt);
}
template <class Impl>
void
FullO3CPU<Impl>::DcachePort::recvRetry()
{
lsq->recvRetry();
}
template <class Impl>
FullO3CPU<Impl>::TickEvent::TickEvent(FullO3CPU<Impl> *c)
: Event(CPU_Tick_Pri), cpu(c)
{
}
template <class Impl>
void
FullO3CPU<Impl>::TickEvent::process()
{
cpu->tick();
}
template <class Impl>
const char *
FullO3CPU<Impl>::TickEvent::description() const
{
return "FullO3CPU tick";
}
template <class Impl>
FullO3CPU<Impl>::ActivateThreadEvent::ActivateThreadEvent()
: Event(CPU_Switch_Pri)
{
}
template <class Impl>
void
FullO3CPU<Impl>::ActivateThreadEvent::init(int thread_num,
FullO3CPU<Impl> *thread_cpu)
{
tid = thread_num;
cpu = thread_cpu;
}
template <class Impl>
void
FullO3CPU<Impl>::ActivateThreadEvent::process()
{
cpu->activateThread(tid);
}
template <class Impl>
const char *
FullO3CPU<Impl>::ActivateThreadEvent::description() const
{
return "FullO3CPU \"Activate Thread\"";
}
template <class Impl>
FullO3CPU<Impl>::DeallocateContextEvent::DeallocateContextEvent()
: Event(CPU_Tick_Pri), tid(0), remove(false), cpu(NULL)
{
}
template <class Impl>
void
FullO3CPU<Impl>::DeallocateContextEvent::init(int thread_num,
FullO3CPU<Impl> *thread_cpu)
{
tid = thread_num;
cpu = thread_cpu;
remove = false;
}
template <class Impl>
void
FullO3CPU<Impl>::DeallocateContextEvent::process()
{
cpu->deactivateThread(tid);
if (remove)
cpu->removeThread(tid);
}
template <class Impl>
const char *
FullO3CPU<Impl>::DeallocateContextEvent::description() const
{
return "FullO3CPU \"Deallocate Context\"";
}
template <class Impl>
FullO3CPU<Impl>::FullO3CPU(DerivO3CPUParams *params)
: BaseO3CPU(params),
itb(params->itb),
dtb(params->dtb),
tickEvent(this),
#ifndef NDEBUG
instcount(0),
#endif
removeInstsThisCycle(false),
fetch(this, params),
decode(this, params),
rename(this, params),
iew(this, params),
commit(this, params),
regFile(this, params->numPhysIntRegs,
params->numPhysFloatRegs),
freeList(params->numThreads,
TheISA::NumIntRegs, params->numPhysIntRegs,
TheISA::NumFloatRegs, params->numPhysFloatRegs),
rob(this,
params->numROBEntries, params->squashWidth,
params->smtROBPolicy, params->smtROBThreshold,
params->numThreads),
scoreboard(params->numThreads,
TheISA::NumIntRegs, params->numPhysIntRegs,
TheISA::NumFloatRegs, params->numPhysFloatRegs,
TheISA::NumMiscRegs * numThreads,
TheISA::ZeroReg),
isa(numThreads, NULL),
icachePort(&fetch, this),
dcachePort(&iew.ldstQueue, this),
timeBuffer(params->backComSize, params->forwardComSize),
fetchQueue(params->backComSize, params->forwardComSize),
decodeQueue(params->backComSize, params->forwardComSize),
renameQueue(params->backComSize, params->forwardComSize),
iewQueue(params->backComSize, params->forwardComSize),
activityRec(name(), NumStages,
params->backComSize + params->forwardComSize,
params->activity),
globalSeqNum(1),
system(params->system),
drainManager(NULL),
lastRunningCycle(curCycle())
{
if (!params->switched_out) {
_status = Running;
} else {
_status = SwitchedOut;
}
if (params->checker) {
BaseCPU *temp_checker = params->checker;
checker = dynamic_cast<Checker<Impl> *>(temp_checker);
checker->setIcachePort(&icachePort);
checker->setSystem(params->system);
} else {
checker = NULL;
}
if (!FullSystem) {
thread.resize(numThreads);
tids.resize(numThreads);
}
// The stages also need their CPU pointer setup. However this
// must be done at the upper level CPU because they have pointers
// to the upper level CPU, and not this FullO3CPU.
// Set up Pointers to the activeThreads list for each stage
fetch.setActiveThreads(&activeThreads);
decode.setActiveThreads(&activeThreads);
rename.setActiveThreads(&activeThreads);
iew.setActiveThreads(&activeThreads);
commit.setActiveThreads(&activeThreads);
// Give each of the stages the time buffer they will use.
fetch.setTimeBuffer(&timeBuffer);
decode.setTimeBuffer(&timeBuffer);
rename.setTimeBuffer(&timeBuffer);
iew.setTimeBuffer(&timeBuffer);
commit.setTimeBuffer(&timeBuffer);
// Also setup each of the stages' queues.
fetch.setFetchQueue(&fetchQueue);
decode.setFetchQueue(&fetchQueue);
commit.setFetchQueue(&fetchQueue);
decode.setDecodeQueue(&decodeQueue);
rename.setDecodeQueue(&decodeQueue);
rename.setRenameQueue(&renameQueue);
iew.setRenameQueue(&renameQueue);
iew.setIEWQueue(&iewQueue);
commit.setIEWQueue(&iewQueue);
commit.setRenameQueue(&renameQueue);
commit.setIEWStage(&iew);
rename.setIEWStage(&iew);
rename.setCommitStage(&commit);
ThreadID active_threads;
if (FullSystem) {
active_threads = 1;
} else {
active_threads = params->workload.size();
if (active_threads > Impl::MaxThreads) {
panic("Workload Size too large. Increase the 'MaxThreads' "
"constant in your O3CPU impl. file (e.g. o3/alpha/impl.hh) "
"or edit your workload size.");
}
}
//Make Sure That this a Valid Architeture
assert(params->numPhysIntRegs >= numThreads * TheISA::NumIntRegs);
assert(params->numPhysFloatRegs >= numThreads * TheISA::NumFloatRegs);
rename.setScoreboard(&scoreboard);
iew.setScoreboard(&scoreboard);
// Setup the rename map for whichever stages need it.
PhysRegIndex lreg_idx = 0;
PhysRegIndex freg_idx = params->numPhysIntRegs; //Index to 1 after int regs
for (ThreadID tid = 0; tid < numThreads; tid++) {
bool bindRegs = (tid <= active_threads - 1);
isa[tid] = params->isa[tid];
commitRenameMap[tid].init(TheISA::NumIntRegs,
params->numPhysIntRegs,
lreg_idx, //Index for Logical. Regs
TheISA::NumFloatRegs,
params->numPhysFloatRegs,
freg_idx, //Index for Float Regs
TheISA::NumMiscRegs,
TheISA::ZeroReg,
TheISA::ZeroReg,
tid,
false);
renameMap[tid].init(TheISA::NumIntRegs,
params->numPhysIntRegs,
lreg_idx, //Index for Logical. Regs
TheISA::NumFloatRegs,
params->numPhysFloatRegs,
freg_idx, //Index for Float Regs
TheISA::NumMiscRegs,
TheISA::ZeroReg,
TheISA::ZeroReg,
tid,
bindRegs);
activateThreadEvent[tid].init(tid, this);
deallocateContextEvent[tid].init(tid, this);
}
rename.setRenameMap(renameMap);
commit.setRenameMap(commitRenameMap);
// Give renameMap & rename stage access to the freeList;
for (ThreadID tid = 0; tid < numThreads; tid++)
renameMap[tid].setFreeList(&freeList);
rename.setFreeList(&freeList);
// Setup the ROB for whichever stages need it.
commit.setROB(&rob);
lastActivatedCycle = 0;
#if 0
// Give renameMap & rename stage access to the freeList;
for (ThreadID tid = 0; tid < numThreads; tid++)
globalSeqNum[tid] = 1;
#endif
contextSwitch = false;
DPRINTF(O3CPU, "Creating O3CPU object.\n");
// Setup any thread state.
this->thread.resize(this->numThreads);
for (ThreadID tid = 0; tid < this->numThreads; ++tid) {
if (FullSystem) {
// SMT is not supported in FS mode yet.
assert(this->numThreads == 1);
this->thread[tid] = new Thread(this, 0, NULL);
} else {
if (tid < params->workload.size()) {
DPRINTF(O3CPU, "Workload[%i] process is %#x",
tid, this->thread[tid]);
this->thread[tid] = new typename FullO3CPU<Impl>::Thread(
(typename Impl::O3CPU *)(this),
tid, params->workload[tid]);
//usedTids[tid] = true;
//threadMap[tid] = tid;
} else {
//Allocate Empty thread so M5 can use later
//when scheduling threads to CPU
Process* dummy_proc = NULL;
this->thread[tid] = new typename FullO3CPU<Impl>::Thread(
(typename Impl::O3CPU *)(this),
tid, dummy_proc);
//usedTids[tid] = false;
}
}
ThreadContext *tc;
// Setup the TC that will serve as the interface to the threads/CPU.
O3ThreadContext<Impl> *o3_tc = new O3ThreadContext<Impl>;
tc = o3_tc;
// If we're using a checker, then the TC should be the
// CheckerThreadContext.
if (params->checker) {
tc = new CheckerThreadContext<O3ThreadContext<Impl> >(
o3_tc, this->checker);
}
o3_tc->cpu = (typename Impl::O3CPU *)(this);
assert(o3_tc->cpu);
o3_tc->thread = this->thread[tid];
if (FullSystem) {
// Setup quiesce event.
this->thread[tid]->quiesceEvent = new EndQuiesceEvent(tc);
}
// Give the thread the TC.
this->thread[tid]->tc = tc;
// Add the TC to the CPU's list of TC's.
this->threadContexts.push_back(tc);
}
// FullO3CPU always requires an interrupt controller.
if (!params->switched_out && !interrupts) {
fatal("FullO3CPU %s has no interrupt controller.\n"
"Ensure createInterruptController() is called.\n", name());
}
for (ThreadID tid = 0; tid < this->numThreads; tid++)
this->thread[tid]->setFuncExeInst(0);
}
template <class Impl>
FullO3CPU<Impl>::~FullO3CPU()
{
}
template <class Impl>
void
FullO3CPU<Impl>::regStats()
{
BaseO3CPU::regStats();
// Register any of the O3CPU's stats here.
timesIdled
.name(name() + ".timesIdled")
.desc("Number of times that the entire CPU went into an idle state and"
" unscheduled itself")
.prereq(timesIdled);
idleCycles
.name(name() + ".idleCycles")
.desc("Total number of cycles that the CPU has spent unscheduled due "
"to idling")
.prereq(idleCycles);
quiesceCycles
.name(name() + ".quiesceCycles")
.desc("Total number of cycles that CPU has spent quiesced or waiting "
"for an interrupt")
.prereq(quiesceCycles);
// Number of Instructions simulated
// --------------------------------
// Should probably be in Base CPU but need templated
// MaxThreads so put in here instead
committedInsts
.init(numThreads)
.name(name() + ".committedInsts")
.desc("Number of Instructions Simulated");
committedOps
.init(numThreads)
.name(name() + ".committedOps")
.desc("Number of Ops (including micro ops) Simulated");
totalCommittedInsts
.name(name() + ".committedInsts_total")
.desc("Number of Instructions Simulated");
cpi
.name(name() + ".cpi")
.desc("CPI: Cycles Per Instruction")
.precision(6);
cpi = numCycles / committedInsts;
totalCpi
.name(name() + ".cpi_total")
.desc("CPI: Total CPI of All Threads")
.precision(6);
totalCpi = numCycles / totalCommittedInsts;
ipc
.name(name() + ".ipc")
.desc("IPC: Instructions Per Cycle")
.precision(6);
ipc = committedInsts / numCycles;
totalIpc
.name(name() + ".ipc_total")
.desc("IPC: Total IPC of All Threads")
.precision(6);
totalIpc = totalCommittedInsts / numCycles;
this->fetch.regStats();
this->decode.regStats();
this->rename.regStats();
this->iew.regStats();
this->commit.regStats();
this->rob.regStats();
intRegfileReads
.name(name() + ".int_regfile_reads")
.desc("number of integer regfile reads")
.prereq(intRegfileReads);
intRegfileWrites
.name(name() + ".int_regfile_writes")
.desc("number of integer regfile writes")
.prereq(intRegfileWrites);
fpRegfileReads
.name(name() + ".fp_regfile_reads")
.desc("number of floating regfile reads")
.prereq(fpRegfileReads);
fpRegfileWrites
.name(name() + ".fp_regfile_writes")
.desc("number of floating regfile writes")
.prereq(fpRegfileWrites);
miscRegfileReads
.name(name() + ".misc_regfile_reads")
.desc("number of misc regfile reads")
.prereq(miscRegfileReads);
miscRegfileWrites
.name(name() + ".misc_regfile_writes")
.desc("number of misc regfile writes")
.prereq(miscRegfileWrites);
}
template <class Impl>
void
FullO3CPU<Impl>::tick()
{
DPRINTF(O3CPU, "\n\nFullO3CPU: Ticking main, FullO3CPU.\n");
assert(!switchedOut());
assert(getDrainState() != Drainable::Drained);
++numCycles;
// activity = false;
//Tick each of the stages
fetch.tick();
decode.tick();
rename.tick();
iew.tick();
commit.tick();
if (!FullSystem)
doContextSwitch();
// Now advance the time buffers
timeBuffer.advance();
fetchQueue.advance();
decodeQueue.advance();
renameQueue.advance();
iewQueue.advance();
activityRec.advance();
if (removeInstsThisCycle) {
cleanUpRemovedInsts();
}
if (!tickEvent.scheduled()) {
if (_status == SwitchedOut) {
DPRINTF(O3CPU, "Switched out!\n");
// increment stat
lastRunningCycle = curCycle();
} else if (!activityRec.active() || _status == Idle) {
DPRINTF(O3CPU, "Idle!\n");
lastRunningCycle = curCycle();
timesIdled++;
} else {
schedule(tickEvent, clockEdge(Cycles(1)));
DPRINTF(O3CPU, "Scheduling next tick!\n");
}
}
if (!FullSystem)
updateThreadPriority();
tryDrain();
}
template <class Impl>
void
FullO3CPU<Impl>::init()
{
BaseCPU::init();
if (!params()->switched_out &&
system->getMemoryMode() != Enums::timing) {
fatal("The O3 CPU requires the memory system to be in "
"'timing' mode.\n");
}
for (ThreadID tid = 0; tid < numThreads; ++tid) {
// Set noSquashFromTC so that the CPU doesn't squash when initially
// setting up registers.
thread[tid]->noSquashFromTC = true;
// Initialise the ThreadContext's memory proxies
thread[tid]->initMemProxies(thread[tid]->getTC());
}
if (FullSystem && !params()->switched_out) {
for (ThreadID tid = 0; tid < numThreads; tid++) {
ThreadContext *src_tc = threadContexts[tid];
TheISA::initCPU(src_tc, src_tc->contextId());
}
}
// Clear noSquashFromTC.
for (int tid = 0; tid < numThreads; ++tid)
thread[tid]->noSquashFromTC = false;
commit.setThreads(thread);
}
template <class Impl>
void
FullO3CPU<Impl>::startup()
{
fetch.startupStage();
decode.startupStage();
iew.startupStage();
rename.startupStage();
commit.startupStage();
}
template <class Impl>
void
FullO3CPU<Impl>::activateThread(ThreadID tid)
{
list<ThreadID>::iterator isActive =
std::find(activeThreads.begin(), activeThreads.end(), tid);
DPRINTF(O3CPU, "[tid:%i]: Calling activate thread.\n", tid);
assert(!switchedOut());
if (isActive == activeThreads.end()) {
DPRINTF(O3CPU, "[tid:%i]: Adding to active threads list\n",
tid);
activeThreads.push_back(tid);
}
}
template <class Impl>
void
FullO3CPU<Impl>::deactivateThread(ThreadID tid)
{
//Remove From Active List, if Active
list<ThreadID>::iterator thread_it =
std::find(activeThreads.begin(), activeThreads.end(), tid);
DPRINTF(O3CPU, "[tid:%i]: Calling deactivate thread.\n", tid);
assert(!switchedOut());
if (thread_it != activeThreads.end()) {
DPRINTF(O3CPU,"[tid:%i]: Removing from active threads list\n",
tid);
activeThreads.erase(thread_it);
}
}
template <class Impl>
Counter
FullO3CPU<Impl>::totalInsts() const
{
Counter total(0);
ThreadID size = thread.size();
for (ThreadID i = 0; i < size; i++)
total += thread[i]->numInst;
return total;
}
template <class Impl>
Counter
FullO3CPU<Impl>::totalOps() const
{
Counter total(0);
ThreadID size = thread.size();
for (ThreadID i = 0; i < size; i++)
total += thread[i]->numOp;
return total;
}
template <class Impl>
void
FullO3CPU<Impl>::activateContext(ThreadID tid, Cycles delay)
{
assert(!switchedOut());
// Needs to set each stage to running as well.
if (delay){
DPRINTF(O3CPU, "[tid:%i]: Scheduling thread context to activate "
"on cycle %d\n", tid, clockEdge(delay));
scheduleActivateThreadEvent(tid, delay);
} else {
activateThread(tid);
}
// We don't want to wake the CPU if it is drained. In that case,
// we just want to flag the thread as active and schedule the tick
// event from drainResume() instead.
if (getDrainState() == Drainable::Drained)
return;
// If we are time 0 or if the last activation time is in the past,
// schedule the next tick and wake up the fetch unit
if (lastActivatedCycle == 0 || lastActivatedCycle < curTick()) {
scheduleTickEvent(delay);
// Be sure to signal that there's some activity so the CPU doesn't
// deschedule itself.
activityRec.activity();
fetch.wakeFromQuiesce();
Cycles cycles(curCycle() - lastRunningCycle);
// @todo: This is an oddity that is only here to match the stats
if (cycles != 0)
--cycles;
quiesceCycles += cycles;
lastActivatedCycle = curTick();
_status = Running;
}
}
template <class Impl>
bool
FullO3CPU<Impl>::scheduleDeallocateContext(ThreadID tid, bool remove,
Cycles delay)
{
// Schedule removal of thread data from CPU
if (delay){
DPRINTF(O3CPU, "[tid:%i]: Scheduling thread context to deallocate "
"on tick %d\n", tid, clockEdge(delay));
scheduleDeallocateContextEvent(tid, remove, delay);
return false;
} else {
deactivateThread(tid);
if (remove)
removeThread(tid);
return true;
}
}
template <class Impl>
void
FullO3CPU<Impl>::suspendContext(ThreadID tid)
{
DPRINTF(O3CPU,"[tid: %i]: Suspending Thread Context.\n", tid);
assert(!switchedOut());
bool deallocated = scheduleDeallocateContext(tid, false, Cycles(1));
// If this was the last thread then unschedule the tick event.
if ((activeThreads.size() == 1 && !deallocated) ||
activeThreads.size() == 0)
unscheduleTickEvent();
DPRINTF(Quiesce, "Suspending Context\n");
lastRunningCycle = curCycle();
_status = Idle;
}
template <class Impl>
void
FullO3CPU<Impl>::haltContext(ThreadID tid)
{
//For now, this is the same as deallocate
DPRINTF(O3CPU,"[tid:%i]: Halt Context called. Deallocating", tid);
assert(!switchedOut());
scheduleDeallocateContext(tid, true, Cycles(1));
}
template <class Impl>
void
FullO3CPU<Impl>::insertThread(ThreadID tid)
{
DPRINTF(O3CPU,"[tid:%i] Initializing thread into CPU");
// Will change now that the PC and thread state is internal to the CPU
// and not in the ThreadContext.
ThreadContext *src_tc;
if (FullSystem)
src_tc = system->threadContexts[tid];
else
src_tc = tcBase(tid);
//Bind Int Regs to Rename Map
for (int ireg = 0; ireg < TheISA::NumIntRegs; ireg++) {
PhysRegIndex phys_reg = freeList.getIntReg();
renameMap[tid].setEntry(ireg,phys_reg);
scoreboard.setReg(phys_reg);
}
//Bind Float Regs to Rename Map
for (int freg = 0; freg < TheISA::NumFloatRegs; freg++) {
PhysRegIndex phys_reg = freeList.getFloatReg();
renameMap[tid].setEntry(freg,phys_reg);
scoreboard.setReg(phys_reg);
}
//Copy Thread Data Into RegFile
//this->copyFromTC(tid);
//Set PC/NPC/NNPC
pcState(src_tc->pcState(), tid);
src_tc->setStatus(ThreadContext::Active);
activateContext(tid, Cycles(1));
//Reset ROB/IQ/LSQ Entries
commit.rob->resetEntries();
iew.resetEntries();
}
template <class Impl>
void
FullO3CPU<Impl>::removeThread(ThreadID tid)
{
DPRINTF(O3CPU,"[tid:%i] Removing thread context from CPU.\n", tid);
// Copy Thread Data From RegFile
// If thread is suspended, it might be re-allocated
// this->copyToTC(tid);
// @todo: 2-27-2008: Fix how we free up rename mappings
// here to alleviate the case for double-freeing registers
// in SMT workloads.
// Unbind Int Regs from Rename Map
for (int ireg = 0; ireg < TheISA::NumIntRegs; ireg++) {
PhysRegIndex phys_reg = renameMap[tid].lookup(ireg);
scoreboard.unsetReg(phys_reg);
freeList.addReg(phys_reg);
}
// Unbind Float Regs from Rename Map
for (int freg = TheISA::NumIntRegs; freg < TheISA::NumFloatRegs; freg++) {
PhysRegIndex phys_reg = renameMap[tid].lookup(freg);
scoreboard.unsetReg(phys_reg);
freeList.addReg(phys_reg);
}
// Squash Throughout Pipeline
DynInstPtr inst = commit.rob->readHeadInst(tid);
InstSeqNum squash_seq_num = inst->seqNum;
fetch.squash(0, squash_seq_num, inst, tid);
decode.squash(tid);
rename.squash(squash_seq_num, tid);
iew.squash(tid);
iew.ldstQueue.squash(squash_seq_num, tid);
commit.rob->squash(squash_seq_num, tid);
assert(iew.instQueue.getCount(tid) == 0);
assert(iew.ldstQueue.getCount(tid) == 0);
// Reset ROB/IQ/LSQ Entries
// Commented out for now. This should be possible to do by
// telling all the pipeline stages to drain first, and then
// checking until the drain completes. Once the pipeline is
// drained, call resetEntries(). - 10-09-06 ktlim
/*
if (activeThreads.size() >= 1) {
commit.rob->resetEntries();
iew.resetEntries();
}
*/
}
template <class Impl>
void
FullO3CPU<Impl>::activateWhenReady(ThreadID tid)
{
DPRINTF(O3CPU,"[tid:%i]: Checking if resources are available for incoming"
"(e.g. PhysRegs/ROB/IQ/LSQ) \n",
tid);
bool ready = true;
if (freeList.numFreeIntRegs() >= TheISA::NumIntRegs) {
DPRINTF(O3CPU,"[tid:%i] Suspending thread due to not enough "
"Phys. Int. Regs.\n",
tid);
ready = false;
} else if (freeList.numFreeFloatRegs() >= TheISA::NumFloatRegs) {
DPRINTF(O3CPU,"[tid:%i] Suspending thread due to not enough "
"Phys. Float. Regs.\n",
tid);
ready = false;
} else if (commit.rob->numFreeEntries() >=
commit.rob->entryAmount(activeThreads.size() + 1)) {
DPRINTF(O3CPU,"[tid:%i] Suspending thread due to not enough "
"ROB entries.\n",
tid);
ready = false;
} else if (iew.instQueue.numFreeEntries() >=
iew.instQueue.entryAmount(activeThreads.size() + 1)) {
DPRINTF(O3CPU,"[tid:%i] Suspending thread due to not enough "
"IQ entries.\n",
tid);
ready = false;
} else if (iew.ldstQueue.numFreeEntries() >=
iew.ldstQueue.entryAmount(activeThreads.size() + 1)) {
DPRINTF(O3CPU,"[tid:%i] Suspending thread due to not enough "
"LSQ entries.\n",
tid);
ready = false;
}
if (ready) {
insertThread(tid);
contextSwitch = false;
cpuWaitList.remove(tid);
} else {
suspendContext(tid);
//blocks fetch
contextSwitch = true;
//@todo: dont always add to waitlist
//do waitlist
cpuWaitList.push_back(tid);
}
}
template <class Impl>
Fault
FullO3CPU<Impl>::hwrei(ThreadID tid)
{
#if THE_ISA == ALPHA_ISA
// Need to clear the lock flag upon returning from an interrupt.
this->setMiscRegNoEffect(AlphaISA::MISCREG_LOCKFLAG, false, tid);
this->thread[tid]->kernelStats->hwrei();
// FIXME: XXX check for interrupts? XXX
#endif
return NoFault;
}
template <class Impl>
bool
FullO3CPU<Impl>::simPalCheck(int palFunc, ThreadID tid)
{
#if THE_ISA == ALPHA_ISA
if (this->thread[tid]->kernelStats)
this->thread[tid]->kernelStats->callpal(palFunc,
this->threadContexts[tid]);
switch (palFunc) {
case PAL::halt:
halt();
if (--System::numSystemsRunning == 0)
exitSimLoop("all cpus halted");
break;
case PAL::bpt:
case PAL::bugchk:
if (this->system->breakpoint())
return false;
break;
}
#endif
return true;
}
template <class Impl>
Fault
FullO3CPU<Impl>::getInterrupts()
{
// Check if there are any outstanding interrupts
return this->interrupts->getInterrupt(this->threadContexts[0]);
}
template <class Impl>
void
FullO3CPU<Impl>::processInterrupts(Fault interrupt)
{
// Check for interrupts here. For now can copy the code that
// exists within isa_fullsys_traits.hh. Also assume that thread 0
// is the one that handles the interrupts.
// @todo: Possibly consolidate the interrupt checking code.
// @todo: Allow other threads to handle interrupts.
assert(interrupt != NoFault);
this->interrupts->updateIntrInfo(this->threadContexts[0]);
DPRINTF(O3CPU, "Interrupt %s being handled\n", interrupt->name());
this->trap(interrupt, 0, NULL);
}
template <class Impl>
void
FullO3CPU<Impl>::trap(Fault fault, ThreadID tid, StaticInstPtr inst)
{
// Pass the thread's TC into the invoke method.
fault->invoke(this->threadContexts[tid], inst);
}
template <class Impl>
void
FullO3CPU<Impl>::syscall(int64_t callnum, ThreadID tid)
{
DPRINTF(O3CPU, "[tid:%i] Executing syscall().\n\n", tid);
DPRINTF(Activity,"Activity: syscall() called.\n");
// Temporarily increase this by one to account for the syscall
// instruction.
++(this->thread[tid]->funcExeInst);
// Execute the actual syscall.
this->thread[tid]->syscall(callnum);
// Decrease funcExeInst by one as the normal commit will handle
// incrementing it.
--(this->thread[tid]->funcExeInst);
}
template <class Impl>
void
FullO3CPU<Impl>::serialize(std::ostream &os)
{
Drainable::State so_state(getDrainState());
SERIALIZE_ENUM(so_state);
BaseCPU::serialize(os);
nameOut(os, csprintf("%s.tickEvent", name()));
tickEvent.serialize(os);
for (ThreadID i = 0; i < thread.size(); i++) {
nameOut(os, csprintf("%s.xc.%i", name(), i));
thread[i]->serialize(os);
}
}
template <class Impl>
void
FullO3CPU<Impl>::unserialize(Checkpoint *cp, const std::string &section)
{
Drainable::State so_state;
UNSERIALIZE_ENUM(so_state);
BaseCPU::unserialize(cp, section);
tickEvent.unserialize(cp, csprintf("%s.tickEvent", section));
for (ThreadID i = 0; i < thread.size(); i++) {
thread[i]->unserialize(cp,
csprintf("%s.xc.%i", section, i));
if (thread[i]->status() == ThreadContext::Active)
activateThread(i);
}
}
template <class Impl>
unsigned int
FullO3CPU<Impl>::drain(DrainManager *drain_manager)
{
// If the CPU isn't doing anything, then return immediately.
if (switchedOut()) {
setDrainState(Drainable::Drained);
return 0;
}
DPRINTF(Drain, "Draining...\n");
setDrainState(Drainable::Draining);
// We only need to signal a drain to the commit stage as this
// initiates squashing controls the draining. Once the commit
// stage commits an instruction where it is safe to stop, it'll
// squash the rest of the instructions in the pipeline and force
// the fetch stage to stall. The pipeline will be drained once all
// in-flight instructions have retired.
commit.drain();
// Wake the CPU and record activity so everything can drain out if
// the CPU was not able to immediately drain.
if (!isDrained()) {
drainManager = drain_manager;
wakeCPU();
activityRec.activity();
DPRINTF(Drain, "CPU not drained\n");
return 1;
} else {
setDrainState(Drainable::Drained);
DPRINTF(Drain, "CPU is already drained\n");
if (tickEvent.scheduled())
deschedule(tickEvent);
// Flush out any old data from the time buffers. In
// particular, there might be some data in flight from the
// fetch stage that isn't visible in any of the CPU buffers we
// test in isDrained().
for (int i = 0; i < timeBuffer.getSize(); ++i) {
timeBuffer.advance();
fetchQueue.advance();
decodeQueue.advance();
renameQueue.advance();
iewQueue.advance();
}
drainSanityCheck();
return 0;
}
}
template <class Impl>
bool
FullO3CPU<Impl>::tryDrain()
{
if (!drainManager || !isDrained())
return false;
if (tickEvent.scheduled())
deschedule(tickEvent);
DPRINTF(Drain, "CPU done draining, processing drain event\n");
drainManager->signalDrainDone();
drainManager = NULL;
return true;
}
template <class Impl>
void
FullO3CPU<Impl>::drainSanityCheck() const
{
assert(isDrained());
fetch.drainSanityCheck();
decode.drainSanityCheck();
rename.drainSanityCheck();
iew.drainSanityCheck();
commit.drainSanityCheck();
}
template <class Impl>
bool
FullO3CPU<Impl>::isDrained() const
{
bool drained(true);
for (ThreadID i = 0; i < thread.size(); ++i) {
if (activateThreadEvent[i].scheduled()) {
DPRINTF(Drain, "CPU not drained, tread %i has a "
"pending activate event\n", i);
drained = false;
}
if (deallocateContextEvent[i].scheduled()) {
DPRINTF(Drain, "CPU not drained, tread %i has a "
"pending deallocate context event\n", i);
drained = false;
}
}
if (!instList.empty() || !removeList.empty()) {
DPRINTF(Drain, "Main CPU structures not drained.\n");
drained = false;
}
if (!fetch.isDrained()) {
DPRINTF(Drain, "Fetch not drained.\n");
drained = false;
}
if (!decode.isDrained()) {
DPRINTF(Drain, "Decode not drained.\n");
drained = false;
}
if (!rename.isDrained()) {
DPRINTF(Drain, "Rename not drained.\n");
drained = false;
}
if (!iew.isDrained()) {
DPRINTF(Drain, "IEW not drained.\n");
drained = false;
}
if (!commit.isDrained()) {
DPRINTF(Drain, "Commit not drained.\n");
drained = false;
}
return drained;
}
template <class Impl>
void
FullO3CPU<Impl>::commitDrained(ThreadID tid)
{
fetch.drainStall(tid);
}
template <class Impl>
void
FullO3CPU<Impl>::drainResume()
{
setDrainState(Drainable::Running);
if (switchedOut())
return;
DPRINTF(Drain, "Resuming...\n");
if (system->getMemoryMode() != Enums::timing) {
fatal("The O3 CPU requires the memory system to be in "
"'timing' mode.\n");
}
fetch.drainResume();
commit.drainResume();
_status = Idle;
for (ThreadID i = 0; i < thread.size(); i++) {
if (thread[i]->status() == ThreadContext::Active) {
DPRINTF(Drain, "Activating thread: %i\n", i);
activateThread(i);
_status = Running;
}
}
assert(!tickEvent.scheduled());
if (_status == Running)
schedule(tickEvent, nextCycle());
}
template <class Impl>
void
FullO3CPU<Impl>::switchOut()
{
DPRINTF(O3CPU, "Switching out\n");
BaseCPU::switchOut();
activityRec.reset();
_status = SwitchedOut;
if (checker)
checker->switchOut();
}
template <class Impl>
void
FullO3CPU<Impl>::takeOverFrom(BaseCPU *oldCPU)
{
BaseCPU::takeOverFrom(oldCPU);
fetch.takeOverFrom();
decode.takeOverFrom();
rename.takeOverFrom();
iew.takeOverFrom();
commit.takeOverFrom();
assert(!tickEvent.scheduled());
FullO3CPU<Impl> *oldO3CPU = dynamic_cast<FullO3CPU<Impl>*>(oldCPU);
if (oldO3CPU)
globalSeqNum = oldO3CPU->globalSeqNum;
lastRunningCycle = curCycle();
_status = Idle;
}
template <class Impl>
TheISA::MiscReg
FullO3CPU<Impl>::readMiscRegNoEffect(int misc_reg, ThreadID tid)
{
return this->isa[tid]->readMiscRegNoEffect(misc_reg);
}
template <class Impl>
TheISA::MiscReg
FullO3CPU<Impl>::readMiscReg(int misc_reg, ThreadID tid)
{
miscRegfileReads++;
return this->isa[tid]->readMiscReg(misc_reg, tcBase(tid));
}
template <class Impl>
void
FullO3CPU<Impl>::setMiscRegNoEffect(int misc_reg,
const TheISA::MiscReg &val, ThreadID tid)
{
this->isa[tid]->setMiscRegNoEffect(misc_reg, val);
}
template <class Impl>
void
FullO3CPU<Impl>::setMiscReg(int misc_reg,
const TheISA::MiscReg &val, ThreadID tid)
{
miscRegfileWrites++;
this->isa[tid]->setMiscReg(misc_reg, val, tcBase(tid));
}
template <class Impl>
uint64_t
FullO3CPU<Impl>::readIntReg(int reg_idx)
{
intRegfileReads++;
return regFile.readIntReg(reg_idx);
}
template <class Impl>
FloatReg
FullO3CPU<Impl>::readFloatReg(int reg_idx)
{
fpRegfileReads++;
return regFile.readFloatReg(reg_idx);
}
template <class Impl>
FloatRegBits
FullO3CPU<Impl>::readFloatRegBits(int reg_idx)
{
fpRegfileReads++;
return regFile.readFloatRegBits(reg_idx);
}
template <class Impl>
void
FullO3CPU<Impl>::setIntReg(int reg_idx, uint64_t val)
{
intRegfileWrites++;
regFile.setIntReg(reg_idx, val);
}
template <class Impl>
void
FullO3CPU<Impl>::setFloatReg(int reg_idx, FloatReg val)
{
fpRegfileWrites++;
regFile.setFloatReg(reg_idx, val);
}
template <class Impl>
void
FullO3CPU<Impl>::setFloatRegBits(int reg_idx, FloatRegBits val)
{
fpRegfileWrites++;
regFile.setFloatRegBits(reg_idx, val);
}
template <class Impl>
uint64_t
FullO3CPU<Impl>::readArchIntReg(int reg_idx, ThreadID tid)
{
intRegfileReads++;
PhysRegIndex phys_reg = commitRenameMap[tid].lookup(reg_idx);
return regFile.readIntReg(phys_reg);
}
template <class Impl>
float
FullO3CPU<Impl>::readArchFloatReg(int reg_idx, ThreadID tid)
{
fpRegfileReads++;
int idx = reg_idx + TheISA::NumIntRegs;
PhysRegIndex phys_reg = commitRenameMap[tid].lookup(idx);
return regFile.readFloatReg(phys_reg);
}
template <class Impl>
uint64_t
FullO3CPU<Impl>::readArchFloatRegInt(int reg_idx, ThreadID tid)
{
fpRegfileReads++;
int idx = reg_idx + TheISA::NumIntRegs;
PhysRegIndex phys_reg = commitRenameMap[tid].lookup(idx);
return regFile.readFloatRegBits(phys_reg);
}
template <class Impl>
void
FullO3CPU<Impl>::setArchIntReg(int reg_idx, uint64_t val, ThreadID tid)
{
intRegfileWrites++;
PhysRegIndex phys_reg = commitRenameMap[tid].lookup(reg_idx);
regFile.setIntReg(phys_reg, val);
}
template <class Impl>
void
FullO3CPU<Impl>::setArchFloatReg(int reg_idx, float val, ThreadID tid)
{
fpRegfileWrites++;
int idx = reg_idx + TheISA::NumIntRegs;
PhysRegIndex phys_reg = commitRenameMap[tid].lookup(idx);
regFile.setFloatReg(phys_reg, val);
}
template <class Impl>
void
FullO3CPU<Impl>::setArchFloatRegInt(int reg_idx, uint64_t val, ThreadID tid)
{
fpRegfileWrites++;
int idx = reg_idx + TheISA::NumIntRegs;
PhysRegIndex phys_reg = commitRenameMap[tid].lookup(idx);
regFile.setFloatRegBits(phys_reg, val);
}
template <class Impl>
TheISA::PCState
FullO3CPU<Impl>::pcState(ThreadID tid)
{
return commit.pcState(tid);
}
template <class Impl>
void
FullO3CPU<Impl>::pcState(const TheISA::PCState &val, ThreadID tid)
{
commit.pcState(val, tid);
}
template <class Impl>
Addr
FullO3CPU<Impl>::instAddr(ThreadID tid)
{
return commit.instAddr(tid);
}
template <class Impl>
Addr
FullO3CPU<Impl>::nextInstAddr(ThreadID tid)
{
return commit.nextInstAddr(tid);
}
template <class Impl>
MicroPC
FullO3CPU<Impl>::microPC(ThreadID tid)
{
return commit.microPC(tid);
}
template <class Impl>
void
FullO3CPU<Impl>::squashFromTC(ThreadID tid)
{
this->thread[tid]->noSquashFromTC = true;
this->commit.generateTCEvent(tid);
}
template <class Impl>
typename FullO3CPU<Impl>::ListIt
FullO3CPU<Impl>::addInst(DynInstPtr &inst)
{
instList.push_back(inst);
return --(instList.end());
}
template <class Impl>
void
FullO3CPU<Impl>::instDone(ThreadID tid, DynInstPtr &inst)
{
// Keep an instruction count.
if (!inst->isMicroop() || inst->isLastMicroop()) {
thread[tid]->numInst++;
thread[tid]->numInsts++;
committedInsts[tid]++;
totalCommittedInsts++;
}
thread[tid]->numOp++;
thread[tid]->numOps++;
committedOps[tid]++;
system->totalNumInsts++;
// Check for instruction-count-based events.
comInstEventQueue[tid]->serviceEvents(thread[tid]->numInst);
system->instEventQueue.serviceEvents(system->totalNumInsts);
}
template <class Impl>
void
FullO3CPU<Impl>::removeFrontInst(DynInstPtr &inst)
{
DPRINTF(O3CPU, "Removing committed instruction [tid:%i] PC %s "
"[sn:%lli]\n",
inst->threadNumber, inst->pcState(), inst->seqNum);
removeInstsThisCycle = true;
// Remove the front instruction.
removeList.push(inst->getInstListIt());
}
template <class Impl>
void
FullO3CPU<Impl>::removeInstsNotInROB(ThreadID tid)
{
DPRINTF(O3CPU, "Thread %i: Deleting instructions from instruction"
" list.\n", tid);
ListIt end_it;
bool rob_empty = false;
if (instList.empty()) {
return;
} else if (rob.isEmpty(/*tid*/)) {
DPRINTF(O3CPU, "ROB is empty, squashing all insts.\n");
end_it = instList.begin();
rob_empty = true;
} else {
end_it = (rob.readTailInst(tid))->getInstListIt();
DPRINTF(O3CPU, "ROB is not empty, squashing insts not in ROB.\n");
}
removeInstsThisCycle = true;
ListIt inst_it = instList.end();
inst_it--;
// Walk through the instruction list, removing any instructions
// that were inserted after the given instruction iterator, end_it.
while (inst_it != end_it) {
assert(!instList.empty());
squashInstIt(inst_it, tid);
inst_it--;
}
// If the ROB was empty, then we actually need to remove the first
// instruction as well.
if (rob_empty) {
squashInstIt(inst_it, tid);
}
}
template <class Impl>
void
FullO3CPU<Impl>::removeInstsUntil(const InstSeqNum &seq_num, ThreadID tid)
{
assert(!instList.empty());
removeInstsThisCycle = true;
ListIt inst_iter = instList.end();
inst_iter--;
DPRINTF(O3CPU, "Deleting instructions from instruction "
"list that are from [tid:%i] and above [sn:%lli] (end=%lli).\n",
tid, seq_num, (*inst_iter)->seqNum);
while ((*inst_iter)->seqNum > seq_num) {
bool break_loop = (inst_iter == instList.begin());
squashInstIt(inst_iter, tid);
inst_iter--;
if (break_loop)
break;
}
}
template <class Impl>
inline void
FullO3CPU<Impl>::squashInstIt(const ListIt &instIt, ThreadID tid)
{
if ((*instIt)->threadNumber == tid) {
DPRINTF(O3CPU, "Squashing instruction, "
"[tid:%i] [sn:%lli] PC %s\n",
(*instIt)->threadNumber,
(*instIt)->seqNum,
(*instIt)->pcState());
// Mark it as squashed.
(*instIt)->setSquashed();
// @todo: Formulate a consistent method for deleting
// instructions from the instruction list
// Remove the instruction from the list.
removeList.push(instIt);
}
}
template <class Impl>
void
FullO3CPU<Impl>::cleanUpRemovedInsts()
{
while (!removeList.empty()) {
DPRINTF(O3CPU, "Removing instruction, "
"[tid:%i] [sn:%lli] PC %s\n",
(*removeList.front())->threadNumber,
(*removeList.front())->seqNum,
(*removeList.front())->pcState());
instList.erase(removeList.front());
removeList.pop();
}
removeInstsThisCycle = false;
}
/*
template <class Impl>
void
FullO3CPU<Impl>::removeAllInsts()
{
instList.clear();
}
*/
template <class Impl>
void
FullO3CPU<Impl>::dumpInsts()
{
int num = 0;
ListIt inst_list_it = instList.begin();
cprintf("Dumping Instruction List\n");
while (inst_list_it != instList.end()) {
cprintf("Instruction:%i\nPC:%#x\n[tid:%i]\n[sn:%lli]\nIssued:%i\n"
"Squashed:%i\n\n",
num, (*inst_list_it)->instAddr(), (*inst_list_it)->threadNumber,
(*inst_list_it)->seqNum, (*inst_list_it)->isIssued(),
(*inst_list_it)->isSquashed());
inst_list_it++;
++num;
}
}
/*
template <class Impl>
void
FullO3CPU<Impl>::wakeDependents(DynInstPtr &inst)
{
iew.wakeDependents(inst);
}
*/
template <class Impl>
void
FullO3CPU<Impl>::wakeCPU()
{
if (activityRec.active() || tickEvent.scheduled()) {
DPRINTF(Activity, "CPU already running.\n");
return;
}
DPRINTF(Activity, "Waking up CPU\n");
Cycles cycles(curCycle() - lastRunningCycle);
// @todo: This is an oddity that is only here to match the stats
if (cycles != 0)
--cycles;
idleCycles += cycles;
numCycles += cycles;
schedule(tickEvent, nextCycle());
}
template <class Impl>
void
FullO3CPU<Impl>::wakeup()
{
if (this->thread[0]->status() != ThreadContext::Suspended)
return;
this->wakeCPU();
DPRINTF(Quiesce, "Suspended Processor woken\n");
this->threadContexts[0]->activate();
}
template <class Impl>
ThreadID
FullO3CPU<Impl>::getFreeTid()
{
for (ThreadID tid = 0; tid < numThreads; tid++) {
if (!tids[tid]) {
tids[tid] = true;
return tid;
}
}
return InvalidThreadID;
}
template <class Impl>
void
FullO3CPU<Impl>::doContextSwitch()
{
if (contextSwitch) {
//ADD CODE TO DEACTIVE THREAD HERE (???)
ThreadID size = cpuWaitList.size();
for (ThreadID tid = 0; tid < size; tid++) {
activateWhenReady(tid);
}
if (cpuWaitList.size() == 0)
contextSwitch = true;
}
}
template <class Impl>
void
FullO3CPU<Impl>::updateThreadPriority()
{
if (activeThreads.size() > 1) {
//DEFAULT TO ROUND ROBIN SCHEME
//e.g. Move highest priority to end of thread list
list<ThreadID>::iterator list_begin = activeThreads.begin();
unsigned high_thread = *list_begin;
activeThreads.erase(list_begin);
activeThreads.push_back(high_thread);
}
}
// Forward declaration of FullO3CPU.
template class FullO3CPU<O3CPUImpl>;
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