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Diffstat (limited to 'src/cpu/o3/fu_pool.hh')
| -rw-r--r-- | src/cpu/o3/fu_pool.hh | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/src/cpu/o3/fu_pool.hh b/src/cpu/o3/fu_pool.hh new file mode 100644 index 000000000..52d83f056 --- /dev/null +++ b/src/cpu/o3/fu_pool.hh @@ -0,0 +1,167 @@ +/* + * 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__ |