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 --- 52 unchanged lines hidden (view full) --- 61 : QueuedPrefetcher(p), 62 maxConf(p->max_conf), 63 threshConf(p->thresh_conf), 64 minConf(p->min_conf), 65 startConf(p->start_conf), 66 pcTableAssoc(p->table_assoc), 67 pcTableSets(p->table_sets), 68 useMasterId(p->use_master_id), |
69 degree(p->degree) |
70{ 71 assert(isPowerOf2(pcTableSets)); 72} 73 |
74StridePrefetcher::PCTable* 75StridePrefetcher::findTable(int context) |
76{ |
77 // Check if table for given context exists 78 auto it = pcTables.find(context); 79 if (it != pcTables.end()) 80 return &it->second; |
81 |
82 // If table does not exist yet, create one 83 return allocateNewContext(context); 84} 85 86StridePrefetcher::PCTable* 87StridePrefetcher::allocateNewContext(int context) 88{ 89 // Create new table 90 auto insertion_result = pcTables.insert(std::make_pair(context, 91 PCTable(pcTableAssoc, pcTableSets, name()))); 92 |
93 DPRINTF(HWPrefetch, "Adding context %i with stride entries\n", context); 94 |
95 // Get iterator to new pc table, and then return a pointer to the new table 96 return &(insertion_result.first->second); 97} 98 99StridePrefetcher::PCTable::PCTable(int assoc, int sets, const std::string name) 100 : pcTableAssoc(assoc), pcTableSets(sets), _name(name), entries(pcTableSets) 101{ 102 for (auto& set : entries) { |
103 set.resize(pcTableAssoc); 104 } |
105} 106 107StridePrefetcher::PCTable::~PCTable() 108{ 109} 110 111void 112StridePrefetcher::calculatePrefetch(const PacketPtr &pkt, --- 5 unchanged lines hidden (view full) --- 118 } 119 120 // Get required packet info 121 Addr pkt_addr = pkt->getAddr(); 122 Addr pc = pkt->req->getPC(); 123 bool is_secure = pkt->isSecure(); 124 MasterID master_id = useMasterId ? pkt->req->masterId() : 0; 125 |
126 // Get corresponding pc table 127 PCTable* pcTable = findTable(master_id); 128 |
129 // Search for entry in the pc table |
130 StrideEntry *entry = pcTable->findEntry(pc, is_secure); |
131 132 if (entry != nullptr) { 133 // Hit in table 134 int new_stride = pkt_addr - entry->lastAddr; 135 bool stride_match = (new_stride == entry->stride); 136 137 // Adjust confidence for stride entry 138 if (stride_match && new_stride != 0) { --- 37 unchanged lines hidden (view full) --- 176 return; 177 } 178 } 179 } else { 180 // Miss in table 181 DPRINTF(HWPrefetch, "Miss: PC %x pkt_addr %x (%s)\n", pc, pkt_addr, 182 is_secure ? "s" : "ns"); 183 |
184 StrideEntry* entry = pcTable->findVictim(pc); |
185 entry->instAddr = pc; 186 entry->lastAddr = pkt_addr; 187 entry->isSecure= is_secure; 188 entry->stride = 0; 189 entry->confidence = startConf; 190 } 191} 192 193inline Addr |
194StridePrefetcher::PCTable::pcHash(Addr pc) const |
195{ 196 Addr hash1 = pc >> 1; 197 Addr hash2 = hash1 >> floorLog2(pcTableSets); 198 return (hash1 ^ hash2) & (Addr)(pcTableSets - 1); 199} 200 201inline StridePrefetcher::StrideEntry* |
202StridePrefetcher::PCTable::findVictim(Addr pc) |
203{ 204 // Rand replacement for now 205 int set = pcHash(pc); 206 int way = random_mt.random<int>(0, pcTableAssoc - 1); 207 208 DPRINTF(HWPrefetch, "Victimizing lookup table[%d][%d].\n", set, way); |
209 return &entries[set][way]; |
210} 211 212inline StridePrefetcher::StrideEntry* |
213StridePrefetcher::PCTable::findEntry(Addr pc, bool is_secure) |
214{ 215 int set = pcHash(pc); |
216 std::vector<StrideEntry>& set_entries = entries[set]; |
217 for (int way = 0; way < pcTableAssoc; way++) { 218 StrideEntry* entry = &set_entries[way]; 219 // Search ways for match 220 if ((entry->instAddr == pc) && (entry->isSecure == is_secure)) { 221 DPRINTF(HWPrefetch, "Lookup hit table[%d][%d].\n", set, way); 222 return entry; 223 } 224 } 225 return nullptr; 226} 227 228StridePrefetcher* 229StridePrefetcherParams::create() 230{ 231 return new StridePrefetcher(this); 232} |