shuffle files around for new directory structure

--HG--
rename : cpu/base_cpu.cc => cpu/base.cc
rename : cpu/base_cpu.hh => cpu/base.hh
rename : cpu/beta_cpu/2bit_local_pred.cc => cpu/o3/2bit_local_pred.cc
rename : cpu/beta_cpu/2bit_local_pred.hh => cpu/o3/2bit_local_pred.hh
rename : cpu/beta_cpu/alpha_full_cpu.cc => cpu/o3/alpha_cpu.cc
rename : cpu/beta_cpu/alpha_full_cpu.hh => cpu/o3/alpha_cpu.hh
rename : cpu/beta_cpu/alpha_full_cpu_builder.cc => cpu/o3/alpha_cpu_builder.cc
rename : cpu/beta_cpu/alpha_full_cpu_impl.hh => cpu/o3/alpha_cpu_impl.hh
rename : cpu/beta_cpu/alpha_dyn_inst.cc => cpu/o3/alpha_dyn_inst.cc
rename : cpu/beta_cpu/alpha_dyn_inst.hh => cpu/o3/alpha_dyn_inst.hh
rename : cpu/beta_cpu/alpha_dyn_inst_impl.hh => cpu/o3/alpha_dyn_inst_impl.hh
rename : cpu/beta_cpu/alpha_impl.hh => cpu/o3/alpha_impl.hh
rename : cpu/beta_cpu/alpha_params.hh => cpu/o3/alpha_params.hh
rename : cpu/beta_cpu/bpred_unit.cc => cpu/o3/bpred_unit.cc
rename : cpu/beta_cpu/bpred_unit.hh => cpu/o3/bpred_unit.hh
rename : cpu/beta_cpu/bpred_unit_impl.hh => cpu/o3/bpred_unit_impl.hh
rename : cpu/beta_cpu/btb.cc => cpu/o3/btb.cc
rename : cpu/beta_cpu/btb.hh => cpu/o3/btb.hh
rename : cpu/beta_cpu/comm.hh => cpu/o3/comm.hh
rename : cpu/beta_cpu/commit.cc => cpu/o3/commit.cc
rename : cpu/beta_cpu/commit.hh => cpu/o3/commit.hh
rename : cpu/beta_cpu/commit_impl.hh => cpu/o3/commit_impl.hh
rename : cpu/beta_cpu/full_cpu.cc => cpu/o3/cpu.cc
rename : cpu/beta_cpu/full_cpu.hh => cpu/o3/cpu.hh
rename : cpu/beta_cpu/cpu_policy.hh => cpu/o3/cpu_policy.hh
rename : cpu/beta_cpu/decode.cc => cpu/o3/decode.cc
rename : cpu/beta_cpu/decode.hh => cpu/o3/decode.hh
rename : cpu/beta_cpu/decode_impl.hh => cpu/o3/decode_impl.hh
rename : cpu/beta_cpu/fetch.cc => cpu/o3/fetch.cc
rename : cpu/beta_cpu/fetch.hh => cpu/o3/fetch.hh
rename : cpu/beta_cpu/fetch_impl.hh => cpu/o3/fetch_impl.hh
rename : cpu/beta_cpu/free_list.cc => cpu/o3/free_list.cc
rename : cpu/beta_cpu/free_list.hh => cpu/o3/free_list.hh
rename : cpu/beta_cpu/iew.cc => cpu/o3/iew.cc
rename : cpu/beta_cpu/iew.hh => cpu/o3/iew.hh
rename : cpu/beta_cpu/iew_impl.hh => cpu/o3/iew_impl.hh
rename : cpu/beta_cpu/inst_queue.cc => cpu/o3/inst_queue.cc
rename : cpu/beta_cpu/inst_queue.hh => cpu/o3/inst_queue.hh
rename : cpu/beta_cpu/inst_queue_impl.hh => cpu/o3/inst_queue_impl.hh
rename : cpu/beta_cpu/mem_dep_unit.cc => cpu/o3/mem_dep_unit.cc
rename : cpu/beta_cpu/mem_dep_unit.hh => cpu/o3/mem_dep_unit.hh
rename : cpu/beta_cpu/mem_dep_unit_impl.hh => cpu/o3/mem_dep_unit_impl.hh
rename : cpu/beta_cpu/ras.cc => cpu/o3/ras.cc
rename : cpu/beta_cpu/ras.hh => cpu/o3/ras.hh
rename : cpu/beta_cpu/regfile.hh => cpu/o3/regfile.hh
rename : cpu/beta_cpu/rename.cc => cpu/o3/rename.cc
rename : cpu/beta_cpu/rename.hh => cpu/o3/rename.hh
rename : cpu/beta_cpu/rename_impl.hh => cpu/o3/rename_impl.hh
rename : cpu/beta_cpu/rename_map.cc => cpu/o3/rename_map.cc
rename : cpu/beta_cpu/rename_map.hh => cpu/o3/rename_map.hh
rename : cpu/beta_cpu/rob.cc => cpu/o3/rob.cc
rename : cpu/beta_cpu/rob.hh => cpu/o3/rob.hh
rename : cpu/beta_cpu/rob_impl.hh => cpu/o3/rob_impl.hh
rename : cpu/beta_cpu/sat_counter.cc => cpu/o3/sat_counter.cc
rename : cpu/beta_cpu/sat_counter.hh => cpu/o3/sat_counter.hh
rename : cpu/beta_cpu/store_set.cc => cpu/o3/store_set.cc
rename : cpu/beta_cpu/store_set.hh => cpu/o3/store_set.hh
rename : cpu/beta_cpu/tournament_pred.cc => cpu/o3/tournament_pred.cc
rename : cpu/beta_cpu/tournament_pred.hh => cpu/o3/tournament_pred.hh
rename : cpu/ooo_cpu/ooo_cpu.cc => cpu/ozone/cpu.cc
rename : cpu/ooo_cpu/ooo_cpu.hh => cpu/ozone/cpu.hh
rename : cpu/ooo_cpu/ooo_impl.hh => cpu/ozone/cpu_impl.hh
rename : cpu/ooo_cpu/ea_list.cc => cpu/ozone/ea_list.cc
rename : cpu/ooo_cpu/ea_list.hh => cpu/ozone/ea_list.hh
rename : cpu/simple_cpu/simple_cpu.cc => cpu/simple/cpu.cc
rename : cpu/simple_cpu/simple_cpu.hh => cpu/simple/cpu.hh
rename : cpu/full_cpu/smt.hh => cpu/smt.hh
rename : cpu/full_cpu/op_class.hh => encumbered/cpu/full/op_class.hh
extra : convert_revision : c4a891d8d6d3e0e9e5ea56be47d851da44d8c032

1 files changed, 1135 insertions, 0 deletions

diff --git a/cpu/o3/inst_queue_impl.hh b/cpu/o3/inst_queue_impl.hh
new file mode 100644
index 000000000..2221ba456
--- /dev/null
+++ b/cpu/o3/inst_queue_impl.hh
@@ -0,0 +1,1135 @@
+/*
+ * Copyright (c) 2004-2005 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.
+ */
+
+// Todo:
+// Current ordering allows for 0 cycle added-to-scheduled.  Could maybe fake
+// it; either do in reverse order, or have added instructions put into a
+// different ready queue that, in scheduleRreadyInsts(), gets put onto the
+// normal ready queue.  This would however give only a one cycle delay,
+// but probably is more flexible to actually add in a delay parameter than
+// just running it backwards.
+
+#include <vector>
+
+#include "sim/root.hh"
+
+#include "cpu/o3/inst_queue.hh"
+
+// Either compile error or max int due to sign extension.
+// Hack to avoid compile warnings.
+const InstSeqNum MaxInstSeqNum = 0 - 1;
+
+template <class Impl>
+InstructionQueue<Impl>::InstructionQueue(Params &params)
+    : memDepUnit(params),
+      numEntries(params.numIQEntries),
+      intWidth(params.executeIntWidth),
+      floatWidth(params.executeFloatWidth),
+      branchWidth(params.executeBranchWidth),
+      memoryWidth(params.executeMemoryWidth),
+      totalWidth(params.issueWidth),
+      numPhysIntRegs(params.numPhysIntRegs),
+      numPhysFloatRegs(params.numPhysFloatRegs),
+      commitToIEWDelay(params.commitToIEWDelay)
+{
+    // Initialize the number of free IQ entries.
+    freeEntries = numEntries;
+
+    // Set the number of physical registers as the number of int + float
+    numPhysRegs = numPhysIntRegs + numPhysFloatRegs;
+
+    DPRINTF(IQ, "IQ: There are %i physical registers.\n", numPhysRegs);
+
+    //Create an entry for each physical register within the
+    //dependency graph.
+    dependGraph = new DependencyEntry[numPhysRegs];
+
+    // Resize the register scoreboard.
+    regScoreboard.resize(numPhysRegs);
+
+    // Initialize all the head pointers to point to NULL, and all the
+    // entries as unready.
+    // Note that in actuality, the registers corresponding to the logical
+    // registers start off as ready.  However this doesn't matter for the
+    // IQ as the instruction should have been correctly told if those
+    // registers are ready in rename.  Thus it can all be initialized as
+    // unready.
+    for (int i = 0; i < numPhysRegs; ++i)
+    {
+        dependGraph[i].next = NULL;
+        dependGraph[i].inst = NULL;
+        regScoreboard[i] = false;
+    }
+
+}
+
+template <class Impl>
+void
+InstructionQueue<Impl>::regStats()
+{
+    iqInstsAdded
+        .name(name() + ".iqInstsAdded")
+        .desc("Number of instructions added to the IQ (excludes non-spec)")
+        .prereq(iqInstsAdded);
+
+    iqNonSpecInstsAdded
+        .name(name() + ".iqNonSpecInstsAdded")
+        .desc("Number of non-speculative instructions added to the IQ")
+        .prereq(iqNonSpecInstsAdded);
+
+//    iqIntInstsAdded;
+
+    iqIntInstsIssued
+        .name(name() + ".iqIntInstsIssued")
+        .desc("Number of integer instructions issued")
+        .prereq(iqIntInstsIssued);
+
+//    iqFloatInstsAdded;
+
+    iqFloatInstsIssued
+        .name(name() + ".iqFloatInstsIssued")
+        .desc("Number of float instructions issued")
+        .prereq(iqFloatInstsIssued);
+
+//    iqBranchInstsAdded;
+
+    iqBranchInstsIssued
+        .name(name() + ".iqBranchInstsIssued")
+        .desc("Number of branch instructions issued")
+        .prereq(iqBranchInstsIssued);
+
+//    iqMemInstsAdded;
+
+    iqMemInstsIssued
+        .name(name() + ".iqMemInstsIssued")
+        .desc("Number of memory instructions issued")
+        .prereq(iqMemInstsIssued);
+
+//    iqMiscInstsAdded;
+
+    iqMiscInstsIssued
+        .name(name() + ".iqMiscInstsIssued")
+        .desc("Number of miscellaneous instructions issued")
+        .prereq(iqMiscInstsIssued);
+
+    iqSquashedInstsIssued
+        .name(name() + ".iqSquashedInstsIssued")
+        .desc("Number of squashed instructions issued")
+        .prereq(iqSquashedInstsIssued);
+
+    iqLoopSquashStalls
+        .name(name() + ".iqLoopSquashStalls")
+        .desc("Number of times issue loop had to restart due to squashed "
+              "inst; mainly for profiling")
+        .prereq(iqLoopSquashStalls);
+
+    iqSquashedInstsExamined
+        .name(name() + ".iqSquashedInstsExamined")
+        .desc("Number of squashed instructions iterated over during squash;"
+              " mainly for profiling")
+        .prereq(iqSquashedInstsExamined);
+
+    iqSquashedOperandsExamined
+        .name(name() + ".iqSquashedOperandsExamined")
+        .desc("Number of squashed operands that are examined and possibly "
+              "removed from graph")
+        .prereq(iqSquashedOperandsExamined);
+
+    iqSquashedNonSpecRemoved
+        .name(name() + ".iqSquashedNonSpecRemoved")
+        .desc("Number of squashed non-spec instructions that were removed")
+        .prereq(iqSquashedNonSpecRemoved);
+
+    // Tell mem dependence unit to reg stats as well.
+    memDepUnit.regStats();
+}
+
+template <class Impl>
+void
+InstructionQueue<Impl>::setCPU(FullCPU *cpu_ptr)
+{
+    cpu = cpu_ptr;
+
+    tail = cpu->instList.begin();
+}
+
+template <class Impl>
+void
+InstructionQueue<Impl>::setIssueToExecuteQueue(
+                        TimeBuffer<IssueStruct> *i2e_ptr)
+{
+    DPRINTF(IQ, "IQ: Set the issue to execute queue.\n");
+    issueToExecuteQueue = i2e_ptr;
+}
+
+template <class Impl>
+void
+InstructionQueue<Impl>::setTimeBuffer(TimeBuffer<TimeStruct> *tb_ptr)
+{
+    DPRINTF(IQ, "IQ: Set the time buffer.\n");
+    timeBuffer = tb_ptr;
+
+    fromCommit = timeBuffer->getWire(-commitToIEWDelay);
+}
+
+template <class Impl>
+unsigned
+InstructionQueue<Impl>::numFreeEntries()
+{
+    return freeEntries;
+}
+
+// Might want to do something more complex if it knows how many instructions
+// will be issued this cycle.
+template <class Impl>
+bool
+InstructionQueue<Impl>::isFull()
+{
+    if (freeEntries == 0) {
+        return(true);
+    } else {
+        return(false);
+    }
+}
+
+template <class Impl>
+void
+InstructionQueue<Impl>::insert(DynInstPtr &new_inst)
+{
+    // Make sure the instruction is valid
+    assert(new_inst);
+
+    DPRINTF(IQ, "IQ: Adding instruction PC %#x to the IQ.\n",
+            new_inst->readPC());
+
+    // Check if there are any free entries.  Panic if there are none.
+    // Might want to have this return a fault in the future instead of
+    // panicing.
+    assert(freeEntries != 0);
+
+    // If the IQ currently has nothing in it, then there's a possibility
+    // that the tail iterator is invalid (might have been pointing at an
+    // instruction that was retired).  Reset the tail iterator.
+    if (freeEntries == numEntries) {
+        tail = cpu->instList.begin();
+    }
+
+    // Move the tail iterator.  Instructions may not have been issued
+    // to the IQ, so we may have to increment the iterator more than once.
+    while ((*tail) != new_inst) {
+        tail++;
+
+        // Make sure the tail iterator points at something legal.
+        assert(tail != cpu->instList.end());
+    }
+
+
+    // Decrease the number of free entries.
+    --freeEntries;
+
+    // Look through its source registers (physical regs), and mark any
+    // dependencies.
+    addToDependents(new_inst);
+
+    // Have this instruction set itself as the producer of its destination
+    // register(s).
+    createDependency(new_inst);
+
+    // If it's a memory instruction, add it to the memory dependency
+    // unit.
+    if (new_inst->isMemRef()) {
+        memDepUnit.insert(new_inst);
+        // Uh..forgot to look it up and put it on the proper dependency list
+        // if the instruction should not go yet.
+    } else {
+        // If the instruction is ready then add it to the ready list.
+        addIfReady(new_inst);
+    }
+
+    ++iqInstsAdded;
+
+    assert(freeEntries == (numEntries - countInsts()));
+}
+
+template <class Impl>
+void
+InstructionQueue<Impl>::insertNonSpec(DynInstPtr &inst)
+{
+    nonSpecInsts[inst->seqNum] = inst;
+
+    // @todo: Clean up this code; can do it by setting inst as unable
+    // to issue, then calling normal insert on the inst.
+
+    // Make sure the instruction is valid
+    assert(inst);
+
+    DPRINTF(IQ, "IQ: Adding instruction PC %#x to the IQ.\n",
+            inst->readPC());
+
+    // Check if there are any free entries.  Panic if there are none.
+    // Might want to have this return a fault in the future instead of
+    // panicing.
+    assert(freeEntries != 0);
+
+    // If the IQ currently has nothing in it, then there's a possibility
+    // that the tail iterator is invalid (might have been pointing at an
+    // instruction that was retired).  Reset the tail iterator.
+    if (freeEntries == numEntries) {
+        tail = cpu->instList.begin();
+    }
+
+    // Move the tail iterator.  Instructions may not have been issued
+    // to the IQ, so we may have to increment the iterator more than once.
+    while ((*tail) != inst) {
+        tail++;
+
+        // Make sure the tail iterator points at something legal.
+        assert(tail != cpu->instList.end());
+    }
+
+    // Decrease the number of free entries.
+    --freeEntries;
+
+    // Have this instruction set itself as the producer of its destination
+    // register(s).
+    createDependency(inst);
+
+    // If it's a memory instruction, add it to the memory dependency
+    // unit.
+    if (inst->isMemRef()) {
+        memDepUnit.insertNonSpec(inst);
+    }
+
+    ++iqNonSpecInstsAdded;
+}
+
+// Slightly hack function to advance the tail iterator in the case that
+// the IEW stage issues an instruction that is not added to the IQ.  This
+// is needed in case a long chain of such instructions occurs.
+// I don't think this is used anymore.
+template <class Impl>
+void
+InstructionQueue<Impl>::advanceTail(DynInstPtr &inst)
+{
+    // Make sure the instruction is valid
+    assert(inst);
+
+    DPRINTF(IQ, "IQ: Adding instruction PC %#x to the IQ.\n",
+            inst->readPC());
+
+    // Check if there are any free entries.  Panic if there are none.
+    // Might want to have this return a fault in the future instead of
+    // panicing.
+    assert(freeEntries != 0);
+
+    // If the IQ currently has nothing in it, then there's a possibility
+    // that the tail iterator is invalid (might have been pointing at an
+    // instruction that was retired).  Reset the tail iterator.
+    if (freeEntries == numEntries) {
+        tail = cpu->instList.begin();
+    }
+
+    // Move the tail iterator.  Instructions may not have been issued
+    // to the IQ, so we may have to increment the iterator more than once.
+    while ((*tail) != inst) {
+        tail++;
+
+        // Make sure the tail iterator points at something legal.
+        assert(tail != cpu->instList.end());
+    }
+
+    assert(freeEntries <= numEntries);
+
+    // Have this instruction set itself as the producer of its destination
+    // register(s).
+    createDependency(inst);
+}
+
+// Need to make sure the number of float and integer instructions
+// issued does not exceed the total issue bandwidth.
+// @todo: Figure out a better way to remove the squashed items from the
+// lists.  Checking the top item of each list to see if it's squashed
+// wastes time and forces jumps.
+template <class Impl>
+void
+InstructionQueue<Impl>::scheduleReadyInsts()
+{
+    DPRINTF(IQ, "IQ: Attempting to schedule ready instructions from "
+                "the IQ.\n");
+
+    int int_issued = 0;
+    int float_issued = 0;
+    int branch_issued = 0;
+    int memory_issued = 0;
+    int squashed_issued = 0;
+    int total_issued = 0;
+
+    IssueStruct *i2e_info = issueToExecuteQueue->access(0);
+
+    bool insts_available = !readyBranchInsts.empty() ||
+        !readyIntInsts.empty() ||
+        !readyFloatInsts.empty() ||
+        !memDepUnit.empty() ||
+        !readyMiscInsts.empty() ||
+        !squashedInsts.empty();
+
+    // Note: Requires a globally defined constant.
+    InstSeqNum oldest_inst = MaxInstSeqNum;
+    InstList list_with_oldest = None;
+
+    // Temporary values.
+    DynInstPtr int_head_inst;
+    DynInstPtr float_head_inst;
+    DynInstPtr branch_head_inst;
+    DynInstPtr mem_head_inst;
+    DynInstPtr misc_head_inst;
+    DynInstPtr squashed_head_inst;
+
+    // Somewhat nasty code to look at all of the lists where issuable
+    // instructions are located, and choose the oldest instruction among
+    // those lists.  Consider a rewrite in the future.
+    while (insts_available && total_issued < totalWidth)
+    {
+        // Set this to false.  Each if-block is required to set it to true
+        // if there were instructions available this check.  This will cause
+        // this loop to run once more than necessary, but avoids extra calls.
+        insts_available = false;
+
+        oldest_inst = MaxInstSeqNum;
+
+        list_with_oldest = None;
+
+        if (!readyIntInsts.empty() &&
+            int_issued < intWidth) {
+
+            insts_available = true;
+
+            int_head_inst = readyIntInsts.top();
+
+            if (int_head_inst->isSquashed()) {
+                readyIntInsts.pop();
+
+                ++iqLoopSquashStalls;
+
+                continue;
+            }
+
+            oldest_inst = int_head_inst->seqNum;
+
+            list_with_oldest = Int;
+        }
+
+        if (!readyFloatInsts.empty() &&
+            float_issued < floatWidth) {
+
+            insts_available = true;
+
+            float_head_inst = readyFloatInsts.top();
+
+            if (float_head_inst->isSquashed()) {
+                readyFloatInsts.pop();
+
+                ++iqLoopSquashStalls;
+
+                continue;
+            } else if (float_head_inst->seqNum < oldest_inst) {
+                oldest_inst = float_head_inst->seqNum;
+
+                list_with_oldest = Float;
+            }
+        }
+
+        if (!readyBranchInsts.empty() &&
+            branch_issued < branchWidth) {
+
+            insts_available = true;
+
+            branch_head_inst = readyBranchInsts.top();
+
+            if (branch_head_inst->isSquashed()) {
+                readyBranchInsts.pop();
+
+                ++iqLoopSquashStalls;
+
+                continue;
+            } else if (branch_head_inst->seqNum < oldest_inst) {
+                oldest_inst = branch_head_inst->seqNum;
+
+                list_with_oldest = Branch;
+            }
+
+        }
+
+        if (!memDepUnit.empty() &&
+            memory_issued < memoryWidth) {
+
+            insts_available = true;
+
+            mem_head_inst = memDepUnit.top();
+
+            if (mem_head_inst->isSquashed()) {
+                memDepUnit.pop();
+
+                ++iqLoopSquashStalls;
+
+                continue;
+            } else if (mem_head_inst->seqNum < oldest_inst) {
+                oldest_inst = mem_head_inst->seqNum;
+
+                list_with_oldest = Memory;
+            }
+        }
+
+        if (!readyMiscInsts.empty()) {
+
+            insts_available = true;
+
+            misc_head_inst = readyMiscInsts.top();
+
+            if (misc_head_inst->isSquashed()) {
+                readyMiscInsts.pop();
+
+                ++iqLoopSquashStalls;
+
+                continue;
+            } else if (misc_head_inst->seqNum < oldest_inst) {
+                oldest_inst = misc_head_inst->seqNum;
+
+                list_with_oldest = Misc;
+            }
+        }
+
+        if (!squashedInsts.empty()) {
+
+            insts_available = true;
+
+            squashed_head_inst = squashedInsts.top();
+
+            if (squashed_head_inst->seqNum < oldest_inst) {
+                list_with_oldest = Squashed;
+            }
+
+        }
+
+        DynInstPtr issuing_inst = NULL;
+
+        switch (list_with_oldest) {
+          case None:
+            DPRINTF(IQ, "IQ: Not able to schedule any instructions. Issuing "
+                    "inst is %#x.\n", issuing_inst);
+            break;
+
+          case Int:
+            issuing_inst = int_head_inst;
+            readyIntInsts.pop();
+            ++int_issued;
+            DPRINTF(IQ, "IQ: Issuing integer instruction PC %#x.\n",
+                    issuing_inst->readPC());
+            break;
+
+          case Float:
+            issuing_inst = float_head_inst;
+            readyFloatInsts.pop();
+            ++float_issued;
+            DPRINTF(IQ, "IQ: Issuing float instruction PC %#x.\n",
+                    issuing_inst->readPC());
+            break;
+
+          case Branch:
+            issuing_inst = branch_head_inst;
+            readyBranchInsts.pop();
+            ++branch_issued;
+            DPRINTF(IQ, "IQ: Issuing branch instruction PC %#x.\n",
+                    issuing_inst->readPC());
+            break;
+
+          case Memory:
+            issuing_inst = mem_head_inst;
+
+            memDepUnit.pop();
+            ++memory_issued;
+            DPRINTF(IQ, "IQ: Issuing memory instruction PC %#x.\n",
+                    issuing_inst->readPC());
+            break;
+
+          case Misc:
+            issuing_inst = misc_head_inst;
+            readyMiscInsts.pop();
+
+            ++iqMiscInstsIssued;
+
+            DPRINTF(IQ, "IQ: Issuing a miscellaneous instruction PC %#x.\n",
+                    issuing_inst->readPC());
+            break;
+
+          case Squashed:
+            assert(0 && "Squashed insts should not issue any more!");
+            squashedInsts.pop();
+            // Set the squashed instruction as able to commit so that commit
+            // can just drop it from the ROB.  This is a bit faked.
+            ++squashed_issued;
+            ++freeEntries;
+
+            DPRINTF(IQ, "IQ: Issuing squashed instruction PC %#x.\n",
+                    squashed_head_inst->readPC());
+            break;
+        }
+
+        if (list_with_oldest != None && list_with_oldest != Squashed) {
+            i2e_info->insts[total_issued] = issuing_inst;
+            i2e_info->size++;
+
+            issuing_inst->setIssued();
+
+            ++freeEntries;
+            ++total_issued;
+        }
+
+        assert(freeEntries == (numEntries - countInsts()));
+    }
+
+    iqIntInstsIssued += int_issued;
+    iqFloatInstsIssued += float_issued;
+    iqBranchInstsIssued += branch_issued;
+    iqMemInstsIssued += memory_issued;
+    iqSquashedInstsIssued += squashed_issued;
+}
+
+template <class Impl>
+void
+InstructionQueue<Impl>::scheduleNonSpec(const InstSeqNum &inst)
+{
+    DPRINTF(IQ, "IQ: Marking nonspeculative instruction with sequence "
+            "number %i as ready to execute.\n", inst);
+
+    non_spec_it_t inst_it = nonSpecInsts.find(inst);
+
+    assert(inst_it != nonSpecInsts.end());
+
+    // Mark this instruction as ready to issue.
+    (*inst_it).second->setCanIssue();
+
+    // Now schedule the instruction.
+    if (!(*inst_it).second->isMemRef()) {
+        addIfReady((*inst_it).second);
+    } else {
+        memDepUnit.nonSpecInstReady((*inst_it).second);
+    }
+
+    nonSpecInsts.erase(inst_it);
+}
+
+template <class Impl>
+void
+InstructionQueue<Impl>::wakeDependents(DynInstPtr &completed_inst)
+{
+    DPRINTF(IQ, "IQ: Waking dependents of completed instruction.\n");
+    //Look at the physical destination register of the DynInst
+    //and look it up on the dependency graph.  Then mark as ready
+    //any instructions within the instruction queue.
+    DependencyEntry *curr;
+
+    // Tell the memory dependence unit to wake any dependents on this
+    // instruction if it is a memory instruction.
+
+    if (completed_inst->isMemRef()) {
+        memDepUnit.wakeDependents(completed_inst);
+    }
+
+    for (int dest_reg_idx = 0;
+         dest_reg_idx < completed_inst->numDestRegs();
+         dest_reg_idx++)
+    {
+        PhysRegIndex dest_reg =
+            completed_inst->renamedDestRegIdx(dest_reg_idx);
+
+        // Special case of uniq or control registers.  They are not
+        // handled by the IQ and thus have no dependency graph entry.
+        // @todo Figure out a cleaner way to handle this.
+        if (dest_reg >= numPhysRegs) {
+            continue;
+        }
+
+        DPRINTF(IQ, "IQ: Waking any dependents on register %i.\n",
+                (int) dest_reg);
+
+        //Maybe abstract this part into a function.
+        //Go through the dependency chain, marking the registers as ready
+        //within the waiting instructions.
+        while (dependGraph[dest_reg].next) {
+
+            curr = dependGraph[dest_reg].next;
+
+            DPRINTF(IQ, "IQ: Waking up a dependent instruction, PC%#x.\n",
+                    curr->inst->readPC());
+
+            // Might want to give more information to the instruction
+            // so that it knows which of its source registers is ready.
+            // However that would mean that the dependency graph entries
+            // would need to hold the src_reg_idx.
+            curr->inst->markSrcRegReady();
+
+            addIfReady(curr->inst);
+
+            dependGraph[dest_reg].next = curr->next;
+
+            DependencyEntry::mem_alloc_counter--;
+
+            curr->inst = NULL;
+
+            delete curr;
+        }
+
+        // Reset the head node now that all of its dependents have been woken
+        // up.
+        dependGraph[dest_reg].next = NULL;
+        dependGraph[dest_reg].inst = NULL;
+
+        // Mark the scoreboard as having that register ready.
+        regScoreboard[dest_reg] = true;
+    }
+}
+
+template <class Impl>
+void
+InstructionQueue<Impl>::violation(DynInstPtr &store,
+                                  DynInstPtr &faulting_load)
+{
+    memDepUnit.violation(store, faulting_load);
+}
+
+template <class Impl>
+void
+InstructionQueue<Impl>::squash()
+{
+    DPRINTF(IQ, "IQ: Starting to squash instructions in the IQ.\n");
+
+    // Read instruction sequence number of last instruction out of the
+    // time buffer.
+    squashedSeqNum = fromCommit->commitInfo.doneSeqNum;
+
+    // Setup the squash iterator to point to the tail.
+    squashIt = tail;
+
+    // Call doSquash if there are insts in the IQ
+    if (freeEntries != numEntries) {
+        doSquash();
+    }
+
+    // Also tell the memory dependence unit to squash.
+    memDepUnit.squash(squashedSeqNum);
+}
+
+template <class Impl>
+void
+InstructionQueue<Impl>::doSquash()
+{
+    // Make sure the squash iterator isn't pointing to nothing.
+    assert(squashIt != cpu->instList.end());
+    // Make sure the squashed sequence number is valid.
+    assert(squashedSeqNum != 0);
+
+    DPRINTF(IQ, "IQ: Squashing instructions in the IQ.\n");
+
+    // Squash any instructions younger than the squashed sequence number
+    // given.
+    while ((*squashIt)->seqNum > squashedSeqNum) {
+        DynInstPtr squashed_inst = (*squashIt);
+
+        // Only handle the instruction if it actually is in the IQ and
+        // hasn't already been squashed in the IQ.
+        if (!squashed_inst->isIssued() &&
+            !squashed_inst->isSquashedInIQ()) {
+
+            // Remove the instruction from the dependency list.
+            // Hack for now: These below don't add themselves to the
+            // dependency list, so don't try to remove them.
+            if (!squashed_inst->isNonSpeculative()/* &&
+                                                     !squashed_inst->isStore()*/
+                ) {
+
+                for (int src_reg_idx = 0;
+                     src_reg_idx < squashed_inst->numSrcRegs();
+                     src_reg_idx++)
+                {
+                    PhysRegIndex src_reg =
+                        squashed_inst->renamedSrcRegIdx(src_reg_idx);
+
+                    // Only remove it from the dependency graph if it was
+                    // placed there in the first place.
+                    // HACK: This assumes that instructions woken up from the
+                    // dependency chain aren't informed that a specific src
+                    // register has become ready.  This may not always be true
+                    // in the future.
+                    if (!squashed_inst->isReadySrcRegIdx(src_reg_idx) &&
+                        src_reg < numPhysRegs) {
+                        dependGraph[src_reg].remove(squashed_inst);
+                    }
+
+                    ++iqSquashedOperandsExamined;
+                }
+
+                // Might want to remove producers as well.
+            } else {
+                nonSpecInsts[squashed_inst->seqNum] = NULL;
+
+                nonSpecInsts.erase(squashed_inst->seqNum);
+
+                ++iqSquashedNonSpecRemoved;
+            }
+
+            // Might want to also clear out the head of the dependency graph.
+
+            // Mark it as squashed within the IQ.
+            squashed_inst->setSquashedInIQ();
+
+//            squashedInsts.push(squashed_inst);
+            squashed_inst->setIssued();
+            squashed_inst->setCanCommit();
+
+            ++freeEntries;
+
+            DPRINTF(IQ, "IQ: Instruction PC %#x squashed.\n",
+                    squashed_inst->readPC());
+        }
+
+        --squashIt;
+        ++iqSquashedInstsExamined;
+    }
+
+    assert(freeEntries <= numEntries);
+
+    if (freeEntries == numEntries) {
+        tail = cpu->instList.end();
+    }
+
+}
+
+template <class Impl>
+void
+InstructionQueue<Impl>::stopSquash()
+{
+    // Clear up the squash variables to ensure that squashing doesn't
+    // get called improperly.
+    squashedSeqNum = 0;
+
+    squashIt = cpu->instList.end();
+}
+
+template <class Impl>
+void
+InstructionQueue<Impl>::DependencyEntry::insert(DynInstPtr &new_inst)
+{
+    //Add this new, dependent instruction at the head of the dependency
+    //chain.
+
+    // First create the entry that will be added to the head of the
+    // dependency chain.
+    DependencyEntry *new_entry = new DependencyEntry;
+    new_entry->next = this->next;
+    new_entry->inst = new_inst;
+
+    // Then actually add it to the chain.
+    this->next = new_entry;
+
+    ++mem_alloc_counter;
+}
+
+template <class Impl>
+void
+InstructionQueue<Impl>::DependencyEntry::remove(DynInstPtr &inst_to_remove)
+{
+    DependencyEntry *prev = this;
+    DependencyEntry *curr = this->next;
+
+    // Make sure curr isn't NULL.  Because this instruction is being
+    // removed from a dependency list, it must have been placed there at
+    // an earlier time.  The dependency chain should not be empty,
+    // unless the instruction dependent upon it is already ready.
+    if (curr == NULL) {
+        return;
+    }
+
+    // Find the instruction to remove within the dependency linked list.
+    while(curr->inst != inst_to_remove)
+    {
+        prev = curr;
+        curr = curr->next;
+
+        assert(curr != NULL);
+    }
+
+    // Now remove this instruction from the list.
+    prev->next = curr->next;
+
+    --mem_alloc_counter;
+
+    // Could push this off to the destructor of DependencyEntry
+    curr->inst = NULL;
+
+    delete curr;
+}
+
+template <class Impl>
+bool
+InstructionQueue<Impl>::addToDependents(DynInstPtr &new_inst)
+{
+    // Loop through the instruction's source registers, adding
+    // them to the dependency list if they are not ready.
+    int8_t total_src_regs = new_inst->numSrcRegs();
+    bool return_val = false;
+
+    for (int src_reg_idx = 0;
+         src_reg_idx < total_src_regs;
+         src_reg_idx++)
+    {
+        // Only add it to the dependency graph if it's not ready.
+        if (!new_inst->isReadySrcRegIdx(src_reg_idx)) {
+            PhysRegIndex src_reg = new_inst->renamedSrcRegIdx(src_reg_idx);
+
+            // Check the IQ's scoreboard to make sure the register
+            // hasn't become ready while the instruction was in flight
+            // between stages.  Only if it really isn't ready should
+            // it be added to the dependency graph.
+            if (src_reg >= numPhysRegs) {
+                continue;
+            } else if (regScoreboard[src_reg] == false) {
+                DPRINTF(IQ, "IQ: Instruction PC %#x has src reg %i that "
+                        "is being added to the dependency chain.\n",
+                        new_inst->readPC(), src_reg);
+
+                dependGraph[src_reg].insert(new_inst);
+
+                // Change the return value to indicate that something
+                // was added to the dependency graph.
+                return_val = true;
+            } else {
+                DPRINTF(IQ, "IQ: Instruction PC %#x has src reg %i that "
+                        "became ready before it reached the IQ.\n",
+                        new_inst->readPC(), src_reg);
+                // Mark a register ready within the instruction.
+                new_inst->markSrcRegReady();
+            }
+        }
+    }
+
+    return return_val;
+}
+
+template <class Impl>
+void
+InstructionQueue<Impl>::createDependency(DynInstPtr &new_inst)
+{
+    //Actually nothing really needs to be marked when an
+    //instruction becomes the producer of a register's value,
+    //but for convenience a ptr to the producing instruction will
+    //be placed in the head node of the dependency links.
+    int8_t total_dest_regs = new_inst->numDestRegs();
+
+    for (int dest_reg_idx = 0;
+         dest_reg_idx < total_dest_regs;
+         dest_reg_idx++)
+    {
+        PhysRegIndex dest_reg = new_inst->renamedDestRegIdx(dest_reg_idx);
+
+        // Instructions that use the misc regs will have a reg number
+        // higher than the normal physical registers.  In this case these
+        // registers are not renamed, and there is no need to track
+        // dependencies as these instructions must be executed at commit.
+        if (dest_reg >= numPhysRegs) {
+            continue;
+        }
+
+        dependGraph[dest_reg].inst = new_inst;
+
+        if (dependGraph[dest_reg].next) {
+            dumpDependGraph();
+            panic("IQ: Dependency graph not empty!");
+        }
+
+        // Mark the scoreboard to say it's not yet ready.
+        regScoreboard[dest_reg] = false;
+    }
+}
+
+template <class Impl>
+void
+InstructionQueue<Impl>::addIfReady(DynInstPtr &inst)
+{
+    //If the instruction now has all of its source registers
+    // available, then add it to the list of ready instructions.
+    if (inst->readyToIssue()) {
+
+        //Add the instruction to the proper ready list.
+        if (inst->isControl()) {
+
+            DPRINTF(IQ, "IQ: Branch instruction is ready to issue, "
+                    "putting it onto the ready list, PC %#x.\n",
+                    inst->readPC());
+            readyBranchInsts.push(inst);
+
+        } else if (inst->isMemRef()) {
+
+            DPRINTF(IQ, "IQ: Checking if memory instruction can issue.\n");
+
+            // Message to the mem dependence unit that this instruction has
+            // its registers ready.
+
+            memDepUnit.regsReady(inst);
+
+#if 0
+            if (memDepUnit.readyToIssue(inst)) {
+                DPRINTF(IQ, "IQ: Memory instruction is ready to issue, "
+                        "putting it onto the ready list, PC %#x.\n",
+                        inst->readPC());
+                readyMemInsts.push(inst);
+            } else {
+                // Make dependent on the store.
+                // Will need some way to get the store instruction it should
+                // be dependent upon; then when the store issues it can
+                // put the instruction on the ready list.
+                // Yet another tree?
+                assert(0 && "Instruction has no way to actually issue");
+            }
+#endif
+
+        } else if (inst->isInteger()) {
+
+            DPRINTF(IQ, "IQ: Integer instruction is ready to issue, "
+                    "putting it onto the ready list, PC %#x.\n",
+                    inst->readPC());
+            readyIntInsts.push(inst);
+
+        } else if (inst->isFloating()) {
+
+            DPRINTF(IQ, "IQ: Floating instruction is ready to issue, "
+                    "putting it onto the ready list, PC %#x.\n",
+                    inst->readPC());
+            readyFloatInsts.push(inst);
+
+        } else {
+            DPRINTF(IQ, "IQ: Miscellaneous instruction is ready to issue, "
+                    "putting it onto the ready list, PC %#x..\n",
+                    inst->readPC());
+
+            readyMiscInsts.push(inst);
+        }
+    }
+}
+
+/*
+ * Caution, this function must not be called prior to tail being updated at
+ * least once, otherwise it will fail the assertion.  This is because
+ * instList.begin() actually changes upon the insertion of an element into the
+ * list when the list is empty.
+ */
+template <class Impl>
+int
+InstructionQueue<Impl>::countInsts()
+{
+    ListIt count_it = cpu->instList.begin();
+    int total_insts = 0;
+
+    if (tail == cpu->instList.end())
+        return 0;
+
+    while (count_it != tail) {
+        if (!(*count_it)->isIssued()) {
+            ++total_insts;
+        }
+
+        ++count_it;
+
+        assert(count_it != cpu->instList.end());
+    }
+
+    // Need to count the tail iterator as well.
+    if (count_it != cpu->instList.end() &&
+        (*count_it) &&
+        !(*count_it)->isIssued()) {
+        ++total_insts;
+    }
+
+    return total_insts;
+}
+
+template <class Impl>
+void
+InstructionQueue<Impl>::dumpDependGraph()
+{
+    DependencyEntry *curr;
+
+    for (int i = 0; i < numPhysRegs; ++i)
+    {
+        curr = &dependGraph[i];
+
+        if (curr->inst) {
+            cprintf("dependGraph[%i]: producer: %#x consumer: ", i,
+                    curr->inst->readPC());
+        } else {
+            cprintf("dependGraph[%i]: No producer. consumer: ", i);
+        }
+
+        while (curr->next != NULL) {
+            curr = curr->next;
+
+            cprintf("%#x ", curr->inst->readPC());
+        }
+
+        cprintf("\n");
+    }
+}
+
+template <class Impl>
+void
+InstructionQueue<Impl>::dumpLists()
+{
+    cprintf("Ready integer list size: %i\n", readyIntInsts.size());
+
+    cprintf("Ready float list size: %i\n", readyFloatInsts.size());
+
+    cprintf("Ready branch list size: %i\n", readyBranchInsts.size());
+
+    cprintf("Ready misc list size: %i\n", readyMiscInsts.size());
+
+    cprintf("Squashed list size: %i\n", squashedInsts.size());
+
+    cprintf("Non speculative list size: %i\n", nonSpecInsts.size());
+
+    non_spec_it_t non_spec_it = nonSpecInsts.begin();
+
+    cprintf("Non speculative list: ");
+
+    while (non_spec_it != nonSpecInsts.end()) {
+        cprintf("%#x ", (*non_spec_it).second->readPC());
+        ++non_spec_it;
+    }
+
+    cprintf("\n");
+
+}