Merge ktlim@zizzer:/bk/newmem

into  zamp.eecs.umich.edu:/z/ktlim2/clean/newmem

--HG--
extra : convert_revision : 3d951bbeee0178de47e1bdbe704808544bfe732e

1 files changed, 920 insertions, 0 deletions

diff --git a/cpu/ozone/front_end_impl.hh b/cpu/ozone/front_end_impl.hh
new file mode 100644
index 000000000..ffbcf3340
--- /dev/null
+++ b/cpu/ozone/front_end_impl.hh
@@ -0,0 +1,920 @@
+/*
+ * Copyright (c) 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 "arch/faults.hh"
+#include "arch/isa_traits.hh"
+#include "base/statistics.hh"
+#include "cpu/exec_context.hh"
+#include "cpu/exetrace.hh"
+#include "cpu/ozone/front_end.hh"
+#include "mem/mem_interface.hh"
+#include "sim/byte_swap.hh"
+
+using namespace TheISA;
+
+template <class Impl>
+FrontEnd<Impl>::FrontEnd(Params *params)
+    : branchPred(params),
+      icacheInterface(params->icacheInterface),
+      instBufferSize(0),
+      maxInstBufferSize(params->maxInstBufferSize),
+      width(params->frontEndWidth),
+      freeRegs(params->numPhysicalRegs),
+      numPhysRegs(params->numPhysicalRegs),
+      serializeNext(false),
+      interruptPending(false)
+{
+    switchedOut = false;
+
+    status = Idle;
+
+    memReq = NULL;
+    // Size of cache block.
+    cacheBlkSize = icacheInterface ? icacheInterface->getBlockSize() : 64;
+
+    assert(isPowerOf2(cacheBlkSize));
+
+    // Create mask to get rid of offset bits.
+    cacheBlkMask = (cacheBlkSize - 1);
+
+    // Create space to store a cache line.
+    cacheData = new uint8_t[cacheBlkSize];
+
+    fetchCacheLineNextCycle = true;
+
+    cacheBlkValid = false;
+
+#if !FULL_SYSTEM
+//    pTable = params->pTable;
+#endif
+    fetchFault = NoFault;
+}
+
+template <class Impl>
+std::string
+FrontEnd<Impl>::name() const
+{
+    return cpu->name() + ".frontend";
+}
+
+template <class Impl>
+void
+FrontEnd<Impl>::setCommBuffer(TimeBuffer<CommStruct> *_comm)
+{
+    comm = _comm;
+    // @todo: Hardcoded for now.  Allow this to be set by a latency.
+    fromCommit = comm->getWire(-1);
+}
+
+template <class Impl>
+void
+FrontEnd<Impl>::setXC(ExecContext *xc_ptr)
+{
+    xc = xc_ptr;
+}
+
+template <class Impl>
+void
+FrontEnd<Impl>::regStats()
+{
+    icacheStallCycles
+        .name(name() + ".icacheStallCycles")
+        .desc("Number of cycles fetch is stalled on an Icache miss")
+        .prereq(icacheStallCycles);
+
+    fetchedInsts
+        .name(name() + ".fetchedInsts")
+        .desc("Number of instructions fetch has processed")
+        .prereq(fetchedInsts);
+
+    fetchedBranches
+        .name(name() + ".fetchedBranches")
+        .desc("Number of fetched branches")
+        .prereq(fetchedBranches);
+
+    predictedBranches
+        .name(name() + ".predictedBranches")
+        .desc("Number of branches that fetch has predicted taken")
+        .prereq(predictedBranches);
+
+    fetchCycles
+        .name(name() + ".fetchCycles")
+        .desc("Number of cycles fetch has run and was not squashing or"
+              " blocked")
+        .prereq(fetchCycles);
+
+    fetchIdleCycles
+        .name(name() + ".fetchIdleCycles")
+        .desc("Number of cycles fetch was idle")
+        .prereq(fetchIdleCycles);
+
+    fetchSquashCycles
+        .name(name() + ".fetchSquashCycles")
+        .desc("Number of cycles fetch has spent squashing")
+        .prereq(fetchSquashCycles);
+
+    fetchBlockedCycles
+        .name(name() + ".fetchBlockedCycles")
+        .desc("Number of cycles fetch has spent blocked")
+        .prereq(fetchBlockedCycles);
+
+    fetchedCacheLines
+        .name(name() + ".fetchedCacheLines")
+        .desc("Number of cache lines fetched")
+        .prereq(fetchedCacheLines);
+
+    fetchIcacheSquashes
+        .name(name() + ".fetchIcacheSquashes")
+        .desc("Number of outstanding Icache misses that were squashed")
+        .prereq(fetchIcacheSquashes);
+
+    fetchNisnDist
+        .init(/* base value */ 0,
+              /* last value */ width,
+              /* bucket size */ 1)
+        .name(name() + ".rateDist")
+        .desc("Number of instructions fetched each cycle (Total)")
+        .flags(Stats::pdf);
+
+    idleRate
+        .name(name() + ".idleRate")
+        .desc("Percent of cycles fetch was idle")
+        .prereq(idleRate);
+    idleRate = fetchIdleCycles * 100 / cpu->numCycles;
+
+    branchRate
+        .name(name() + ".branchRate")
+        .desc("Number of branch fetches per cycle")
+        .flags(Stats::total);
+    branchRate = fetchedBranches / cpu->numCycles;
+
+    fetchRate
+        .name(name() + ".rate")
+        .desc("Number of inst fetches per cycle")
+        .flags(Stats::total);
+    fetchRate = fetchedInsts / cpu->numCycles;
+
+    IFQCount
+        .name(name() + ".IFQ:count")
+        .desc("cumulative IFQ occupancy")
+        ;
+
+    IFQFcount
+        .name(name() + ".IFQ:fullCount")
+        .desc("cumulative IFQ full count")
+        .flags(Stats::total)
+        ;
+
+    IFQOccupancy
+        .name(name() + ".IFQ:occupancy")
+        .desc("avg IFQ occupancy (inst's)")
+        ;
+    IFQOccupancy = IFQCount / cpu->numCycles;
+
+    IFQLatency
+        .name(name() + ".IFQ:latency")
+        .desc("avg IFQ occupant latency (cycle's)")
+        .flags(Stats::total)
+        ;
+
+    IFQFullRate
+        .name(name() + ".IFQ:fullRate")
+        .desc("fraction of time (cycles) IFQ was full")
+        .flags(Stats::total);
+        ;
+    IFQFullRate = IFQFcount * Stats::constant(100) / cpu->numCycles;
+
+    dispatchCountStat
+        .name(name() + ".DIS:count")
+        .desc("cumulative count of dispatched insts")
+        .flags(Stats::total)
+        ;
+
+    dispatchedSerializing
+        .name(name() + ".DIS:serializingInsts")
+        .desc("count of serializing insts dispatched")
+        .flags(Stats::total)
+        ;
+
+    dispatchedTempSerializing
+        .name(name() + ".DIS:tempSerializingInsts")
+        .desc("count of temporary serializing insts dispatched")
+        .flags(Stats::total)
+        ;
+
+    dispatchSerializeStallCycles
+        .name(name() + ".DIS:serializeStallCycles")
+        .desc("count of cycles dispatch stalled for serializing inst")
+        .flags(Stats::total)
+        ;
+
+    dispatchRate
+        .name(name() + ".DIS:rate")
+        .desc("dispatched insts per cycle")
+        .flags(Stats::total)
+        ;
+    dispatchRate = dispatchCountStat / cpu->numCycles;
+
+    regIntFull
+        .name(name() + ".REG:int:full")
+        .desc("number of cycles where there were no INT registers")
+        ;
+
+    regFpFull
+        .name(name() + ".REG:fp:full")
+        .desc("number of cycles where there were no FP registers")
+        ;
+    IFQLatency = IFQOccupancy / dispatchRate;
+
+    branchPred.regStats();
+}
+
+template <class Impl>
+void
+FrontEnd<Impl>::tick()
+{
+    if (switchedOut)
+        return;
+
+    // @todo: Maybe I want to just have direct communication...
+    if (fromCommit->doneSeqNum) {
+        branchPred.update(fromCommit->doneSeqNum, 0);
+    }
+
+    IFQCount += instBufferSize;
+    IFQFcount += instBufferSize == maxInstBufferSize;
+
+    // Fetch cache line
+    if (status == IcacheMissComplete) {
+        cacheBlkValid = true;
+
+        status = Running;
+        if (barrierInst)
+            status = SerializeBlocked;
+        if (freeRegs <= 0)
+            status = RenameBlocked;
+        checkBE();
+    } else if (status == IcacheMissStall) {
+        DPRINTF(FE, "Still in Icache miss stall.\n");
+        icacheStallCycles++;
+        return;
+    }
+
+    if (status == RenameBlocked || status == SerializeBlocked ||
+        status == TrapPending || status == BEBlocked) {
+        // Will cause a one cycle bubble between changing state and
+        // restarting.
+        DPRINTF(FE, "In blocked status.\n");
+
+        fetchBlockedCycles++;
+
+        if (status == SerializeBlocked) {
+            dispatchSerializeStallCycles++;
+        }
+        updateStatus();
+        return;
+    } else if (status == QuiescePending) {
+        DPRINTF(FE, "Waiting for quiesce to execute or get squashed.\n");
+        return;
+    } else if (status != IcacheMissComplete) {
+        if (fetchCacheLineNextCycle) {
+            Fault fault = fetchCacheLine();
+            if (fault != NoFault) {
+                handleFault(fault);
+                fetchFault = fault;
+                return;
+            }
+            fetchCacheLineNextCycle = false;
+        }
+        // If miss, stall until it returns.
+        if (status == IcacheMissStall) {
+            // Tell CPU to not tick me for now.
+            return;
+        }
+    }
+
+    fetchCycles++;
+
+    int num_inst = 0;
+
+    // Otherwise loop and process instructions.
+    // One way to hack infinite width is to set width and maxInstBufferSize
+    // both really high.  Inelegant, but probably will work.
+    while (num_inst < width &&
+           instBufferSize < maxInstBufferSize) {
+        // Get instruction from cache line.
+        DynInstPtr inst = getInstFromCacheline();
+
+        if (!inst) {
+            // PC is no longer in the cache line, end fetch.
+            // Might want to check this at the end of the cycle so that
+            // there's no cycle lost to checking for a new cache line.
+            DPRINTF(FE, "Need to get new cache line\n");
+            fetchCacheLineNextCycle = true;
+            break;
+        }
+
+        processInst(inst);
+
+        if (status == SerializeBlocked) {
+            break;
+        }
+
+        // Possibly push into a time buffer that estimates the front end
+        // latency
+        instBuffer.push_back(inst);
+        ++instBufferSize;
+        ++num_inst;
+
+#if FULL_SYSTEM
+        if (inst->isQuiesce()) {
+            warn("%lli: Quiesce instruction encountered, halting fetch!", curTick);
+            status = QuiescePending;
+            break;
+        }
+#endif
+
+        if (inst->predTaken()) {
+            // Start over with tick?
+            break;
+        } else if (freeRegs <= 0) {
+            DPRINTF(FE, "Ran out of free registers to rename to!\n");
+            status = RenameBlocked;
+            break;
+        } else if (serializeNext) {
+            break;
+        }
+    }
+
+    fetchNisnDist.sample(num_inst);
+    checkBE();
+
+    DPRINTF(FE, "Num insts processed: %i, Inst Buffer size: %i, Free "
+            "Regs %i\n", num_inst, instBufferSize, freeRegs);
+}
+
+template <class Impl>
+Fault
+FrontEnd<Impl>::fetchCacheLine()
+{
+    // Read a cache line, based on the current PC.
+#if FULL_SYSTEM
+    // Flag to say whether or not address is physical addr.
+    unsigned flags = cpu->inPalMode(PC) ? PHYSICAL : 0;
+#else
+    unsigned flags = 0;
+#endif // FULL_SYSTEM
+    Fault fault = NoFault;
+
+    if (interruptPending && flags == 0) {
+        return fault;
+    }
+
+    // Align the fetch PC so it's at the start of a cache block.
+    Addr fetch_PC = icacheBlockAlignPC(PC);
+
+    DPRINTF(FE, "Fetching cache line starting at %#x.\n", fetch_PC);
+
+    // Setup the memReq to do a read of the first isntruction's address.
+    // Set the appropriate read size and flags as well.
+    memReq = new MemReq();
+
+    memReq->asid = 0;
+    memReq->thread_num = 0;
+    memReq->data = new uint8_t[64];
+    memReq->xc = xc;
+    memReq->cmd = Read;
+    memReq->reset(fetch_PC, cacheBlkSize, flags);
+
+    // Translate the instruction request.
+    fault = cpu->translateInstReq(memReq);
+
+    // Now do the timing access to see whether or not the instruction
+    // exists within the cache.
+    if (icacheInterface && fault == NoFault) {
+#if FULL_SYSTEM
+        if (cpu->system->memctrl->badaddr(memReq->paddr) ||
+            memReq->flags & UNCACHEABLE) {
+            DPRINTF(FE, "Fetch: Bad address %#x (hopefully on a "
+                    "misspeculating path!",
+                    memReq->paddr);
+            return TheISA::genMachineCheckFault();
+        }
+#endif
+
+        memReq->completionEvent = NULL;
+
+        memReq->time = curTick;
+        fault = cpu->mem->read(memReq, cacheData);
+
+        MemAccessResult res = icacheInterface->access(memReq);
+
+        // If the cache missed then schedule an event to wake
+        // up this stage once the cache miss completes.
+        if (icacheInterface->doEvents() && res != MA_HIT) {
+            memReq->completionEvent = new ICacheCompletionEvent(memReq, this);
+
+            status = IcacheMissStall;
+
+            cacheBlkValid = false;
+
+            DPRINTF(FE, "Cache miss.\n");
+        }  else {
+            DPRINTF(FE, "Cache hit.\n");
+
+            cacheBlkValid = true;
+
+//            memcpy(cacheData, memReq->data, memReq->size);
+        }
+    }
+
+    // Note that this will set the cache block PC a bit earlier than it should
+    // be set.
+    cacheBlkPC = fetch_PC;
+
+    ++fetchedCacheLines;
+
+    DPRINTF(FE, "Done fetching cache line.\n");
+
+    return fault;
+}
+
+template <class Impl>
+void
+FrontEnd<Impl>::processInst(DynInstPtr &inst)
+{
+    if (processBarriers(inst)) {
+        return;
+    }
+
+    Addr inst_PC = inst->readPC();
+
+    if (!inst->isControl()) {
+        inst->setPredTarg(inst->readNextPC());
+    } else {
+        fetchedBranches++;
+        if (branchPred.predict(inst, inst_PC, inst->threadNumber)) {
+            predictedBranches++;
+        }
+    }
+
+    Addr next_PC = inst->readPredTarg();
+
+    DPRINTF(FE, "[sn:%lli] Predicted and processed inst PC %#x, next PC "
+            "%#x\n", inst->seqNum, inst_PC, next_PC);
+
+//    inst->setNextPC(next_PC);
+
+    // Not sure where I should set this
+    PC = next_PC;
+
+    renameInst(inst);
+}
+
+template <class Impl>
+bool
+FrontEnd<Impl>::processBarriers(DynInstPtr &inst)
+{
+    if (serializeNext) {
+        inst->setSerializeBefore();
+        serializeNext = false;
+    } else if (!inst->isSerializing() &&
+               !inst->isIprAccess() &&
+               !inst->isStoreConditional()) {
+        return false;
+    }
+
+    if ((inst->isIprAccess() || inst->isSerializeBefore()) &&
+        !inst->isSerializeHandled()) {
+        DPRINTF(FE, "Serialize before instruction encountered.\n");
+
+        if (!inst->isTempSerializeBefore()) {
+            dispatchedSerializing++;
+            inst->setSerializeHandled();
+        } else {
+            dispatchedTempSerializing++;
+        }
+
+        // Change status over to SerializeBlocked so that other stages know
+        // what this is blocked on.
+        status = SerializeBlocked;
+
+        barrierInst = inst;
+        return true;
+    } else if ((inst->isStoreConditional() || inst->isSerializeAfter())
+               && !inst->isSerializeHandled()) {
+        DPRINTF(FE, "Serialize after instruction encountered.\n");
+
+        inst->setSerializeHandled();
+
+        dispatchedSerializing++;
+
+        serializeNext = true;
+        return false;
+    }
+    return false;
+}
+
+template <class Impl>
+void
+FrontEnd<Impl>::handleFault(Fault &fault)
+{
+    DPRINTF(FE, "Fault at fetch, telling commit\n");
+
+    // We're blocked on the back end until it handles this fault.
+    status = TrapPending;
+
+    // Get a sequence number.
+    InstSeqNum inst_seq = getAndIncrementInstSeq();
+    // We will use a nop in order to carry the fault.
+    ExtMachInst ext_inst = TheISA::NoopMachInst;
+
+    // Create a new DynInst from the dummy nop.
+    DynInstPtr instruction = new DynInst(ext_inst, PC,
+                                         PC+sizeof(MachInst),
+                                         inst_seq, cpu);
+    instruction->setPredTarg(instruction->readNextPC());
+//    instruction->setThread(tid);
+
+//    instruction->setASID(tid);
+
+    instruction->setState(thread);
+
+    instruction->traceData = NULL;
+
+    instruction->fault = fault;
+    instruction->setCanIssue();
+    instBuffer.push_back(instruction);
+    ++instBufferSize;
+}
+
+template <class Impl>
+void
+FrontEnd<Impl>::squash(const InstSeqNum &squash_num, const Addr &next_PC,
+                       const bool is_branch, const bool branch_taken)
+{
+    DPRINTF(FE, "Squashing from [sn:%lli], setting PC to %#x\n",
+            squash_num, next_PC);
+
+    if (fetchFault != NoFault)
+        fetchFault = NoFault;
+
+    while (!instBuffer.empty() &&
+           instBuffer.back()->seqNum > squash_num) {
+        DynInstPtr inst = instBuffer.back();
+
+        DPRINTF(FE, "Squashing instruction [sn:%lli] PC %#x\n",
+                inst->seqNum, inst->readPC());
+
+        inst->clearDependents();
+
+        instBuffer.pop_back();
+        --instBufferSize;
+
+        freeRegs+= inst->numDestRegs();
+    }
+
+    // Copy over rename table from the back end.
+    renameTable.copyFrom(backEnd->renameTable);
+
+    PC = next_PC;
+
+    // Update BP with proper information.
+    if (is_branch) {
+        branchPred.squash(squash_num, next_PC, branch_taken, 0);
+    } else {
+        branchPred.squash(squash_num, 0);
+    }
+
+    // Clear the icache miss if it's outstanding.
+    if (status == IcacheMissStall && icacheInterface) {
+        DPRINTF(FE, "Squashing outstanding Icache miss.\n");
+        memReq = NULL;
+    }
+
+    if (status == SerializeBlocked) {
+        assert(barrierInst->seqNum > squash_num);
+        barrierInst = NULL;
+    }
+
+    // Unless this squash originated from the front end, we're probably
+    // in running mode now.
+    // Actually might want to make this latency dependent.
+    status = Running;
+    fetchCacheLineNextCycle = true;
+}
+
+template <class Impl>
+typename Impl::DynInstPtr
+FrontEnd<Impl>::getInst()
+{
+    if (instBufferSize == 0) {
+        return NULL;
+    }
+
+    DynInstPtr inst = instBuffer.front();
+
+    instBuffer.pop_front();
+
+    --instBufferSize;
+
+    dispatchCountStat++;
+
+    return inst;
+}
+
+template <class Impl>
+void
+FrontEnd<Impl>::processCacheCompletion(MemReqPtr &req)
+{
+    DPRINTF(FE, "Processing cache completion\n");
+
+    // Do something here.
+    if (status != IcacheMissStall ||
+        req != memReq ||
+        switchedOut) {
+        DPRINTF(FE, "Previous fetch was squashed.\n");
+        fetchIcacheSquashes++;
+        return;
+    }
+
+    status = IcacheMissComplete;
+
+/*    if (checkStall(tid)) {
+        fetchStatus[tid] = Blocked;
+    } else {
+        fetchStatus[tid] = IcacheMissComplete;
+    }
+*/
+//    memcpy(cacheData, memReq->data, memReq->size);
+
+    // Reset the completion event to NULL.
+//    memReq->completionEvent = NULL;
+    memReq = NULL;
+}
+
+template <class Impl>
+void
+FrontEnd<Impl>::addFreeRegs(int num_freed)
+{
+    if (status == RenameBlocked && freeRegs + num_freed > 0) {
+        status = Running;
+    }
+
+    DPRINTF(FE, "Adding %i freed registers\n", num_freed);
+
+    freeRegs+= num_freed;
+
+//    assert(freeRegs <= numPhysRegs);
+    if (freeRegs > numPhysRegs)
+        freeRegs = numPhysRegs;
+}
+
+template <class Impl>
+bool
+FrontEnd<Impl>::updateStatus()
+{
+    bool serialize_block = !backEnd->robEmpty() || instBufferSize;
+    bool be_block = cpu->decoupledFrontEnd ? false : backEnd->isBlocked();
+    bool ret_val = false;
+
+    if (status == SerializeBlocked && !serialize_block) {
+        status = SerializeComplete;
+        ret_val = true;
+    }
+
+    if (status == BEBlocked && !be_block) {
+        if (barrierInst) {
+            status = SerializeBlocked;
+        } else {
+            status = Running;
+        }
+        ret_val = true;
+    }
+    return ret_val;
+}
+
+template <class Impl>
+void
+FrontEnd<Impl>::checkBE()
+{
+    bool be_block = cpu->decoupledFrontEnd ? false : backEnd->isBlocked();
+    if (be_block) {
+        if (status == Running || status == Idle) {
+            status = BEBlocked;
+        }
+    }
+}
+
+template <class Impl>
+typename Impl::DynInstPtr
+FrontEnd<Impl>::getInstFromCacheline()
+{
+    if (status == SerializeComplete) {
+        DynInstPtr inst = barrierInst;
+        status = Running;
+        barrierInst = NULL;
+        inst->clearSerializeBefore();
+        return inst;
+    }
+
+    InstSeqNum inst_seq;
+    MachInst inst;
+    // @todo: Fix this magic number used here to handle word offset (and
+    // getting rid of PAL bit)
+    unsigned offset = (PC & cacheBlkMask) & ~3;
+
+    // PC of inst is not in this cache block
+    if (PC >= (cacheBlkPC + cacheBlkSize) || PC < cacheBlkPC || !cacheBlkValid) {
+        return NULL;
+    }
+
+    //////////////////////////
+    // Fetch one instruction
+    //////////////////////////
+
+    // Get a sequence number.
+    inst_seq = getAndIncrementInstSeq();
+
+    // Make sure this is a valid index.
+    assert(offset <= cacheBlkSize - sizeof(MachInst));
+
+    // Get the instruction from the array of the cache line.
+    inst = htog(*reinterpret_cast<MachInst *>(&cacheData[offset]));
+
+    ExtMachInst decode_inst = TheISA::makeExtMI(inst, PC);
+
+    // Create a new DynInst from the instruction fetched.
+    DynInstPtr instruction = new DynInst(decode_inst, PC, PC+sizeof(MachInst),
+                                         inst_seq, cpu);
+
+    instruction->setState(thread);
+
+    DPRINTF(FE, "Instruction [sn:%lli] created, with PC %#x\n%s\n",
+            inst_seq, instruction->readPC(),
+            instruction->staticInst->disassemble(PC));
+
+    instruction->traceData =
+        Trace::getInstRecord(curTick, xc, cpu,
+                             instruction->staticInst,
+                             instruction->readPC(), 0);
+
+    // Increment stat of fetched instructions.
+    ++fetchedInsts;
+
+    return instruction;
+}
+
+template <class Impl>
+void
+FrontEnd<Impl>::renameInst(DynInstPtr &inst)
+{
+    DynInstPtr src_inst = NULL;
+    int num_src_regs = inst->numSrcRegs();
+    if (num_src_regs == 0) {
+        inst->setCanIssue();
+    } else {
+        for (int i = 0; i < num_src_regs; ++i) {
+            src_inst = renameTable[inst->srcRegIdx(i)];
+
+            inst->setSrcInst(src_inst, i);
+
+            DPRINTF(FE, "[sn:%lli]: Src reg %i is inst [sn:%lli]\n",
+                    inst->seqNum, (int)inst->srcRegIdx(i), src_inst->seqNum);
+
+            if (src_inst->isResultReady()) {
+                DPRINTF(FE, "Reg ready.\n");
+                inst->markSrcRegReady(i);
+            } else {
+                DPRINTF(FE, "Adding to dependent list.\n");
+                src_inst->addDependent(inst);
+            }
+        }
+    }
+
+    for (int i = 0; i < inst->numDestRegs(); ++i) {
+        RegIndex idx = inst->destRegIdx(i);
+
+        DPRINTF(FE, "Dest reg %i is now inst [sn:%lli], was previously "
+                "[sn:%lli]\n",
+                (int)inst->destRegIdx(i), inst->seqNum,
+                renameTable[idx]->seqNum);
+
+        inst->setPrevDestInst(renameTable[idx], i);
+
+        renameTable[idx] = inst;
+        --freeRegs;
+    }
+}
+
+template <class Impl>
+void
+FrontEnd<Impl>::wakeFromQuiesce()
+{
+    DPRINTF(FE, "Waking up from quiesce\n");
+    // Hopefully this is safe
+    status = Running;
+}
+
+template <class Impl>
+void
+FrontEnd<Impl>::switchOut()
+{
+    switchedOut = true;
+    cpu->signalSwitched();
+}
+
+template <class Impl>
+void
+FrontEnd<Impl>::doSwitchOut()
+{
+    memReq = NULL;
+    squash(0, 0);
+    instBuffer.clear();
+    instBufferSize = 0;
+    status = Idle;
+}
+
+template <class Impl>
+void
+FrontEnd<Impl>::takeOverFrom(ExecContext *old_xc)
+{
+    assert(freeRegs == numPhysRegs);
+    fetchCacheLineNextCycle = true;
+
+    cacheBlkValid = false;
+
+#if !FULL_SYSTEM
+//    pTable = params->pTable;
+#endif
+    fetchFault = NoFault;
+    serializeNext = false;
+    barrierInst = NULL;
+    status = Running;
+    switchedOut = false;
+    interruptPending = false;
+}
+
+template <class Impl>
+void
+FrontEnd<Impl>::dumpInsts()
+{
+    cprintf("instBuffer size: %i\n", instBuffer.size());
+
+    InstBuffIt buff_it = instBuffer.begin();
+
+    for (int num = 0; buff_it != instBuffer.end(); num++) {
+        cprintf("Instruction:%i\nPC:%#x\n[tid:%i]\n[sn:%lli]\nIssued:%i\n"
+                "Squashed:%i\n\n",
+                num, (*buff_it)->readPC(), (*buff_it)->threadNumber,
+                (*buff_it)->seqNum, (*buff_it)->isIssued(),
+                (*buff_it)->isSquashed());
+        buff_it++;
+    }
+}
+
+template <class Impl>
+FrontEnd<Impl>::ICacheCompletionEvent::ICacheCompletionEvent(MemReqPtr &_req, FrontEnd *fe)
+    : Event(&mainEventQueue, Delayed_Writeback_Pri), req(_req), frontEnd(fe)
+{
+    this->setFlags(Event::AutoDelete);
+}
+
+template <class Impl>
+void
+FrontEnd<Impl>::ICacheCompletionEvent::process()
+{
+    frontEnd->processCacheCompletion(req);
+}
+
+template <class Impl>
+const char *
+FrontEnd<Impl>::ICacheCompletionEvent::description()
+{
+    return "ICache completion event";
+}