stride.hh revision 13424
1/* 2 * Copyright (c) 2012-2013, 2015 ARM Limited 3 * All rights reserved 4 * 5 * The license below extends only to copyright in the software and shall 6 * not be construed as granting a license to any other intellectual 7 * property including but not limited to intellectual property relating 8 * to a hardware implementation of the functionality of the software 9 * licensed hereunder. You may use the software subject to the license 10 * terms below provided that you ensure that this notice is replicated 11 * unmodified and in its entirety in all distributions of the software, 12 * modified or unmodified, in source code or in binary form. 13 * 14 * Copyright (c) 2005 The Regents of The University of Michigan 15 * All rights reserved. 16 * 17 * Redistribution and use in source and binary forms, with or without 18 * modification, are permitted provided that the following conditions are 19 * met: redistributions of source code must retain the above copyright 20 * notice, this list of conditions and the following disclaimer; 21 * redistributions in binary form must reproduce the above copyright 22 * notice, this list of conditions and the following disclaimer in the 23 * documentation and/or other materials provided with the distribution; 24 * neither the name of the copyright holders nor the names of its 25 * contributors may be used to endorse or promote products derived from 26 * this software without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 29 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 30 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 31 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 32 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 33 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 34 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 35 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 36 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 37 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 38 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 39 * 40 * Authors: Ron Dreslinski 41 */ 42 43/** 44 * @file 45 * Describes a strided prefetcher. 46 */ 47 48#ifndef __MEM_CACHE_PREFETCH_STRIDE_HH__ 49#define __MEM_CACHE_PREFETCH_STRIDE_HH__ 50 51#include <string> 52#include <unordered_map> 53#include <vector> 54 55#include "base/types.hh" 56#include "mem/cache/prefetch/queued.hh" 57#include "mem/packet.hh" 58 59struct StridePrefetcherParams; 60 61class StridePrefetcher : public QueuedPrefetcher 62{ 63 protected: 64 const int maxConf; 65 const int threshConf; 66 const int minConf; 67 const int startConf; 68 69 const int pcTableAssoc; 70 const int pcTableSets; 71 72 const bool useMasterId; 73 74 const int degree; 75 76 struct StrideEntry 77 { 78 StrideEntry() : instAddr(0), lastAddr(0), isSecure(false), stride(0), 79 confidence(0) 80 { } 81 82 Addr instAddr; 83 Addr lastAddr; 84 bool isSecure; 85 int stride; 86 int confidence; 87 }; 88 89 class PCTable 90 { 91 public: 92 PCTable(int assoc, int sets, const std::string name) : 93 pcTableAssoc(assoc), pcTableSets(sets), _name(name) {} 94 95 std::vector<std::vector<StrideEntry>>& operator[] (int context) { 96 auto it = entries.find(context); 97 if (it != entries.end()) 98 return it->second; 99 100 return allocateNewContext(context); 101 } 102 103 ~PCTable(); 104 private: 105 const std::string name() {return _name; } 106 const int pcTableAssoc; 107 const int pcTableSets; 108 const std::string _name; 109 std::unordered_map<int, std::vector<std::vector<StrideEntry>>> entries; 110 111 std::vector<std::vector<StrideEntry>>& allocateNewContext(int context); 112 }; 113 PCTable pcTable; 114 115 /** 116 * Search for an entry in the pc table. 117 * 118 * @param pc The PC to look for. 119 * @param is_secure True if the target memory space is secure. 120 * @param master_id The context. 121 * @return Pointer to the entry. 122 */ 123 StrideEntry* findEntry(Addr pc, bool is_secure, int master_id); 124 125 StrideEntry* pcTableVictim(Addr pc, int master_id); 126 127 Addr pcHash(Addr pc) const; 128 public: 129 130 StridePrefetcher(const StridePrefetcherParams *p); 131 132 void calculatePrefetch(const PacketPtr &pkt, 133 std::vector<AddrPriority> &addresses) override; 134}; 135 136#endif // __MEM_CACHE_PREFETCH_STRIDE_HH__ 137