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+/*
+ * 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.
+ *
+ * Authors: Kevin Lim
+ */
+
+#ifndef __CPU_O3_FU_POOL_HH__
+#define __CPU_O3_FU_POOL_HH__
+
+#include <bitset>
+#include <list>
+#include <string>
+#include <vector>
+
+#include "base/sched_list.hh"
+#include "cpu/op_class.hh"
+#include "sim/sim_object.hh"
+
+class FUDesc;
+class FuncUnit;
+
+/**
+ * Pool of FU's, specific to the new CPU model. The old FU pool had lists of
+ * free units and busy units, and whenever a FU was needed it would iterate
+ * through the free units to find a FU that provided the capability. This pool
+ * has lists of units specific to each of the capabilities, and whenever a FU
+ * is needed, it iterates through that list to find a free unit. The previous
+ * FU pool would have to be ticked each cycle to update which units became
+ * free. This FU pool lets the IEW stage handle freeing units, which frees
+ * them as their scheduled execution events complete. This limits units in this
+ * model to either have identical issue and op latencies, or 1 cycle issue
+ * latencies.
+ */
+class FUPool : public SimObject
+{
+ private:
+ /** Maximum op execution latencies, per op class. */
+ unsigned maxOpLatencies[Num_OpClasses];
+ /** Maximum issue latencies, per op class. */
+ unsigned maxIssueLatencies[Num_OpClasses];
+
+ /** Bitvector listing capabilities of this FU pool. */
+ std::bitset<Num_OpClasses> capabilityList;
+
+ /** Bitvector listing which FUs are busy. */
+ std::vector<bool> unitBusy;
+
+ /** List of units to be freed at the end of this cycle. */
+ std::vector<int> unitsToBeFreed;
+
+ /**
+ * Class that implements a circular queue to hold FU indices. The hope is
+ * that FUs that have been just used will be moved to the end of the queue
+ * by iterating through it, thus leaving free units at the head of the
+ * queue.
+ */
+ class FUIdxQueue {
+ public:
+ /** Constructs a circular queue of FU indices. */
+ FUIdxQueue()
+ : idx(0), size(0)
+ { }
+
+ /** Adds a FU to the queue. */
+ inline void addFU(int fu_idx);
+
+ /** Returns the index of the FU at the head of the queue, and changes
+ * the index to the next element.
+ */
+ inline int getFU();
+
+ private:
+ /** Circular queue index. */
+ int idx;
+
+ /** Size of the queue. */
+ int size;
+
+ /** Queue of FU indices. */
+ std::vector<int> funcUnitsIdx;
+ };
+
+ /** Per op class queues of FUs that provide that capability. */
+ FUIdxQueue fuPerCapList[Num_OpClasses];
+
+ /** Number of FUs. */
+ int numFU;
+
+ /** Functional units. */
+ std::vector<FuncUnit *> funcUnits;
+
+ typedef std::vector<FuncUnit *>::iterator fuListIterator;
+
+ public:
+
+ /** Constructs a FU pool. */
+ FUPool(std::string name, std::vector<FUDesc *> l);
+ ~FUPool();
+
+ /** Annotates units that provide memory operations. Included only because
+ * old FU pool provided this function.
+ */
+ void annotateMemoryUnits(unsigned hit_latency);
+
+ /**
+ * Gets a FU providing the requested capability. Will mark the unit as busy,
+ * but leaves the freeing of the unit up to the IEW stage.
+ * @param capability The capability requested.
+ * @return Returns -2 if the FU pool does not have the capability, -1 if
+ * there is no free FU, and the FU's index otherwise.
+ */
+ int getUnit(OpClass capability);
+
+ /** Frees a FU at the end of this cycle. */
+ void freeUnitNextCycle(int fu_idx);
+
+ /** Frees all FUs on the list. */
+ void processFreeUnits();
+
+ /** Returns the total number of FUs. */
+ int size() { return numFU; }
+
+ /** Debugging function used to dump FU information. */
+ void dump();
+
+ /** Returns the operation execution latency of the given capability. */
+ unsigned getOpLatency(OpClass capability) {
+ return maxOpLatencies[capability];
+ }
+
+ /** Returns the issue latency of the given capability. */
+ unsigned getIssueLatency(OpClass capability) {
+ return maxIssueLatencies[capability];
+ }
+
+ /** Switches out functional unit pool. */
+ void switchOut();
+
+ /** Takes over from another CPU's thread. */
+ void takeOverFrom();
+};
+
+#endif // __CPU_O3_FU_POOL_HH__