store_set.cc revision 2292
1/* 2 * Copyright (c) 2004-2005 The Regents of The University of Michigan 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are 7 * met: redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer; 9 * redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution; 12 * neither the name of the copyright holders nor the names of its 13 * contributors may be used to endorse or promote products derived from 14 * this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29#include "base/trace.hh" 30#include "cpu/o3/store_set.hh" 31 32StoreSet::StoreSet(int _SSIT_size, int _LFST_size) 33 : SSITSize(_SSIT_size), LFSTSize(_LFST_size) 34{ 35 DPRINTF(StoreSet, "StoreSet: Creating store set object.\n"); 36 DPRINTF(StoreSet, "StoreSet: SSIT size: %i, LFST size: %i.\n", 37 SSITSize, LFSTSize); 38 39 SSIT.resize(SSITSize); 40 41 validSSIT.resize(SSITSize); 42 43 for (int i = 0; i < SSITSize; ++i) 44 validSSIT[i] = false; 45 46 LFST.resize(LFSTSize); 47 48 validLFST.resize(LFSTSize); 49 50 for (int i = 0; i < LFSTSize; ++i) { 51 validLFST[i] = false; 52 LFST[i] = 0; 53 } 54 55 indexMask = SSITSize - 1; 56 57 offsetBits = 2; 58} 59 60StoreSet::~StoreSet() 61{ 62} 63 64void 65StoreSet::init(int _SSIT_size, int _LFST_size) 66{ 67 SSITSize = _SSIT_size; 68 LFSTSize = _LFST_size; 69 70 DPRINTF(StoreSet, "StoreSet: Creating store set object.\n"); 71 DPRINTF(StoreSet, "StoreSet: SSIT size: %i, LFST size: %i.\n", 72 SSITSize, LFSTSize); 73 74 SSIT.resize(SSITSize); 75 76 validSSIT.resize(SSITSize); 77 78 for (int i = 0; i < SSITSize; ++i) 79 validSSIT[i] = false; 80 81 LFST.resize(LFSTSize); 82 83 validLFST.resize(LFSTSize); 84 85 for (int i = 0; i < LFSTSize; ++i) { 86 validLFST[i] = false; 87 LFST[i] = 0; 88 } 89 90 indexMask = SSITSize - 1; 91 92 offsetBits = 2; 93} 94 95 96void 97StoreSet::violation(Addr store_PC, Addr load_PC) 98{ 99 int load_index = calcIndex(load_PC); 100 int store_index = calcIndex(store_PC); 101 102 assert(load_index < SSITSize && store_index < SSITSize); 103 104 bool valid_load_SSID = validSSIT[load_index]; 105 bool valid_store_SSID = validSSIT[store_index]; 106 107 if (!valid_load_SSID && !valid_store_SSID) { 108 // Calculate a new SSID here. 109 SSID new_set = calcSSID(load_PC); 110 111 validSSIT[load_index] = true; 112 113 SSIT[load_index] = new_set; 114 115 validSSIT[store_index] = true; 116 117 SSIT[store_index] = new_set; 118 119 assert(new_set < LFSTSize); 120 121 DPRINTF(StoreSet, "StoreSet: Neither load nor store had a valid " 122 "storeset, creating a new one: %i for load %#x, store %#x\n", 123 new_set, load_PC, store_PC); 124 } else if (valid_load_SSID && !valid_store_SSID) { 125 SSID load_SSID = SSIT[load_index]; 126 127 validSSIT[store_index] = true; 128 129 SSIT[store_index] = load_SSID; 130 131 assert(load_SSID < LFSTSize); 132 133 DPRINTF(StoreSet, "StoreSet: Load had a valid store set. Adding " 134 "store to that set: %i for load %#x, store %#x\n", 135 load_SSID, load_PC, store_PC); 136 } else if (!valid_load_SSID && valid_store_SSID) { 137 SSID store_SSID = SSIT[store_index]; 138 139 validSSIT[load_index] = true; 140 141 SSIT[load_index] = store_SSID; 142 143 DPRINTF(StoreSet, "StoreSet: Store had a valid store set: %i for " 144 "load %#x, store %#x\n", 145 store_SSID, load_PC, store_PC); 146 } else { 147 SSID load_SSID = SSIT[load_index]; 148 SSID store_SSID = SSIT[store_index]; 149 150 assert(load_SSID < LFSTSize && store_SSID < LFSTSize); 151 152 // The store set with the lower number wins 153 if (store_SSID > load_SSID) { 154 SSIT[store_index] = load_SSID; 155 156 DPRINTF(StoreSet, "StoreSet: Load had smaller store set: %i; " 157 "for load %#x, store %#x\n", 158 load_SSID, load_PC, store_PC); 159 } else { 160 SSIT[load_index] = store_SSID; 161 162 DPRINTF(StoreSet, "StoreSet: Store had smaller store set: %i; " 163 "for load %#x, store %#x\n", 164 store_SSID, load_PC, store_PC); 165 } 166 } 167} 168 169void 170StoreSet::insertLoad(Addr load_PC, InstSeqNum load_seq_num) 171{ 172 // Does nothing. 173 return; 174} 175 176void 177StoreSet::insertStore(Addr store_PC, InstSeqNum store_seq_num, 178 unsigned tid) 179{ 180 int index = calcIndex(store_PC); 181 182 int store_SSID; 183 184 assert(index < SSITSize); 185 186 if (!validSSIT[index]) { 187 // Do nothing if there's no valid entry. 188 return; 189 } else { 190 store_SSID = SSIT[index]; 191 192 assert(store_SSID < LFSTSize); 193 194 // Update the last store that was fetched with the current one. 195 LFST[store_SSID] = store_seq_num; 196 197 validLFST[store_SSID] = 1; 198 199 storeList[store_seq_num] = store_SSID; 200 201 DPRINTF(StoreSet, "Store %#x updated the LFST, SSID: %i\n", 202 store_PC, store_SSID); 203 } 204} 205 206InstSeqNum 207StoreSet::checkInst(Addr PC) 208{ 209 int index = calcIndex(PC); 210 211 int inst_SSID; 212 213 assert(index < SSITSize); 214 215 if (!validSSIT[index]) { 216 DPRINTF(StoreSet, "Inst %#x with index %i had no SSID\n", 217 PC, index); 218 219 // Return 0 if there's no valid entry. 220 return 0; 221 } else { 222 inst_SSID = SSIT[index]; 223 224 assert(inst_SSID < LFSTSize); 225 226 if (!validLFST[inst_SSID]) { 227 228 DPRINTF(StoreSet, "Inst %#x with index %i and SSID %i had no " 229 "dependency\n", PC, index, inst_SSID); 230 231 return 0; 232 } else { 233 DPRINTF(StoreSet, "Inst %#x with index %i and SSID %i had LFST " 234 "inum of %i\n", PC, index, inst_SSID, LFST[inst_SSID]); 235 236 return LFST[inst_SSID]; 237 } 238 } 239} 240 241void 242StoreSet::issued(Addr issued_PC, InstSeqNum issued_seq_num, bool is_store) 243{ 244 // This only is updated upon a store being issued. 245 if (!is_store) { 246 return; 247 } 248 249 int index = calcIndex(issued_PC); 250 251 int store_SSID; 252 253 assert(index < SSITSize); 254 255 SeqNumMapIt store_list_it = storeList.find(issued_seq_num); 256 257 if (store_list_it != storeList.end()) { 258 storeList.erase(store_list_it); 259 } 260 261 // Make sure the SSIT still has a valid entry for the issued store. 262 if (!validSSIT[index]) { 263 return; 264 } 265 266 store_SSID = SSIT[index]; 267 268 assert(store_SSID < LFSTSize); 269 270 // If the last fetched store in the store set refers to the store that 271 // was just issued, then invalidate the entry. 272 if (validLFST[store_SSID] && LFST[store_SSID] == issued_seq_num) { 273 DPRINTF(StoreSet, "StoreSet: store invalidated itself in LFST.\n"); 274 validLFST[store_SSID] = false; 275 } 276} 277 278void 279StoreSet::squash(InstSeqNum squashed_num, unsigned tid) 280{ 281 // Not really sure how to do this well. 282 // Generally this is small enough that it should be okay; short circuit 283 // evaluation should take care of invalid entries. 284 // Maybe keep a list of valid LFST's? Really ugly either way... 285 286 DPRINTF(StoreSet, "StoreSet: Squashing until inum %i\n", 287 squashed_num); 288 289 int idx; 290 SeqNumMapIt store_list_it = storeList.begin(); 291 292 //@todo:Fix to only delete from correct thread 293 while (!storeList.empty()) { 294 idx = (*store_list_it).second; 295 296 if ((*store_list_it).first <= squashed_num) { 297 break; 298 } 299 300 bool younger = LFST[idx] > squashed_num; 301 302 if (validLFST[idx] && younger) { 303 DPRINTF(StoreSet, "Squashed [sn:%lli]\n", LFST[idx]); 304 validLFST[idx] = false; 305 306 storeList.erase(store_list_it++); 307 } else if (!validLFST[idx] && younger) { 308 storeList.erase(store_list_it++); 309 } 310 } 311} 312 313void 314StoreSet::clear() 315{ 316 for (int i = 0; i < SSITSize; ++i) { 317 validSSIT[i] = false; 318 } 319 320 for (int i = 0; i < LFSTSize; ++i) { 321 validLFST[i] = false; 322 } 323 324 storeList.clear(); 325} 326