store_set.cc revision 8519:ef35ce2bd73f 
1/*
2 * Copyright (c) 2004-2006 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 * Authors: Kevin Lim
29 */
30
31#include "base/intmath.hh"
32#include "base/misc.hh"
33#include "base/trace.hh"
34#include "cpu/o3/store_set.hh"
35#include "debug/StoreSet.hh"
36
37StoreSet::StoreSet(uint64_t clear_period, int _SSIT_size, int _LFST_size)
38    : clearPeriod(clear_period), SSITSize(_SSIT_size), LFSTSize(_LFST_size)
39{
40    DPRINTF(StoreSet, "StoreSet: Creating store set object.\n");
41    DPRINTF(StoreSet, "StoreSet: SSIT size: %i, LFST size: %i.\n",
42            SSITSize, LFSTSize);
43
44    if (!isPowerOf2(SSITSize)) {
45        fatal("Invalid SSIT size!\n");
46    }
47
48    SSIT.resize(SSITSize);
49
50    validSSIT.resize(SSITSize);
51
52    for (int i = 0; i < SSITSize; ++i)
53        validSSIT[i] = false;
54
55    if (!isPowerOf2(LFSTSize)) {
56        fatal("Invalid LFST size!\n");
57    }
58
59    LFST.resize(LFSTSize);
60
61    validLFST.resize(LFSTSize);
62
63    for (int i = 0; i < LFSTSize; ++i) {
64        validLFST[i] = false;
65        LFST[i] = 0;
66    }
67
68    indexMask = SSITSize - 1;
69
70    offsetBits = 2;
71
72    memOpsPred = 0;
73}
74
75StoreSet::~StoreSet()
76{
77}
78
79void
80StoreSet::init(uint64_t clear_period, int _SSIT_size, int _LFST_size)
81{
82    SSITSize = _SSIT_size;
83    LFSTSize = _LFST_size;
84    clearPeriod = clear_period;
85
86    DPRINTF(StoreSet, "StoreSet: Creating store set object.\n");
87    DPRINTF(StoreSet, "StoreSet: SSIT size: %i, LFST size: %i.\n",
88            SSITSize, LFSTSize);
89
90    SSIT.resize(SSITSize);
91
92    validSSIT.resize(SSITSize);
93
94    for (int i = 0; i < SSITSize; ++i)
95        validSSIT[i] = false;
96
97    LFST.resize(LFSTSize);
98
99    validLFST.resize(LFSTSize);
100
101    for (int i = 0; i < LFSTSize; ++i) {
102        validLFST[i] = false;
103        LFST[i] = 0;
104    }
105
106    indexMask = SSITSize - 1;
107
108    offsetBits = 2;
109
110    memOpsPred = 0;
111}
112
113
114void
115StoreSet::violation(Addr store_PC, Addr load_PC)
116{
117    int load_index = calcIndex(load_PC);
118    int store_index = calcIndex(store_PC);
119
120    assert(load_index < SSITSize && store_index < SSITSize);
121
122    bool valid_load_SSID = validSSIT[load_index];
123    bool valid_store_SSID = validSSIT[store_index];
124
125    if (!valid_load_SSID && !valid_store_SSID) {
126        // Calculate a new SSID here.
127        SSID new_set = calcSSID(load_PC);
128
129        validSSIT[load_index] = true;
130
131        SSIT[load_index] = new_set;
132
133        validSSIT[store_index] = true;
134
135        SSIT[store_index] = new_set;
136
137        assert(new_set < LFSTSize);
138
139        DPRINTF(StoreSet, "StoreSet: Neither load nor store had a valid "
140                "storeset, creating a new one: %i for load %#x, store %#x\n",
141                new_set, load_PC, store_PC);
142    } else if (valid_load_SSID && !valid_store_SSID) {
143        SSID load_SSID = SSIT[load_index];
144
145        validSSIT[store_index] = true;
146
147        SSIT[store_index] = load_SSID;
148
149        assert(load_SSID < LFSTSize);
150
151        DPRINTF(StoreSet, "StoreSet: Load had a valid store set.  Adding "
152                "store to that set: %i for load %#x, store %#x\n",
153                load_SSID, load_PC, store_PC);
154    } else if (!valid_load_SSID && valid_store_SSID) {
155        SSID store_SSID = SSIT[store_index];
156
157        validSSIT[load_index] = true;
158
159        SSIT[load_index] = store_SSID;
160
161        DPRINTF(StoreSet, "StoreSet: Store had a valid store set: %i for "
162                "load %#x, store %#x\n",
163                store_SSID, load_PC, store_PC);
164    } else {
165        SSID load_SSID = SSIT[load_index];
166        SSID store_SSID = SSIT[store_index];
167
168        assert(load_SSID < LFSTSize && store_SSID < LFSTSize);
169
170        // The store set with the lower number wins
171        if (store_SSID > load_SSID) {
172            SSIT[store_index] = load_SSID;
173
174            DPRINTF(StoreSet, "StoreSet: Load had smaller store set: %i; "
175                    "for load %#x, store %#x\n",
176                    load_SSID, load_PC, store_PC);
177        } else {
178            SSIT[load_index] = store_SSID;
179
180            DPRINTF(StoreSet, "StoreSet: Store had smaller store set: %i; "
181                    "for load %#x, store %#x\n",
182                    store_SSID, load_PC, store_PC);
183        }
184    }
185}
186
187void
188StoreSet::checkClear()
189{
190    memOpsPred++;
191    if (memOpsPred > clearPeriod) {
192        DPRINTF(StoreSet, "Wiping predictor state beacuse %d ld/st executed\n",
193                clearPeriod);
194        memOpsPred = 0;
195        clear();
196    }
197}
198
199void
200StoreSet::insertLoad(Addr load_PC, InstSeqNum load_seq_num)
201{
202    checkClear();
203    // Does nothing.
204    return;
205}
206
207void
208StoreSet::insertStore(Addr store_PC, InstSeqNum store_seq_num, ThreadID tid)
209{
210    int index = calcIndex(store_PC);
211
212    int store_SSID;
213
214    checkClear();
215    assert(index < SSITSize);
216
217    if (!validSSIT[index]) {
218        // Do nothing if there's no valid entry.
219        return;
220    } else {
221        store_SSID = SSIT[index];
222
223        assert(store_SSID < LFSTSize);
224
225        // Update the last store that was fetched with the current one.
226        LFST[store_SSID] = store_seq_num;
227
228        validLFST[store_SSID] = 1;
229
230        storeList[store_seq_num] = store_SSID;
231
232        DPRINTF(StoreSet, "Store %#x updated the LFST, SSID: %i\n",
233                store_PC, store_SSID);
234    }
235}
236
237InstSeqNum
238StoreSet::checkInst(Addr PC)
239{
240    int index = calcIndex(PC);
241
242    int inst_SSID;
243
244    assert(index < SSITSize);
245
246    if (!validSSIT[index]) {
247        DPRINTF(StoreSet, "Inst %#x with index %i had no SSID\n",
248                PC, index);
249
250        // Return 0 if there's no valid entry.
251        return 0;
252    } else {
253        inst_SSID = SSIT[index];
254
255        assert(inst_SSID < LFSTSize);
256
257        if (!validLFST[inst_SSID]) {
258
259            DPRINTF(StoreSet, "Inst %#x with index %i and SSID %i had no "
260                    "dependency\n", PC, index, inst_SSID);
261
262            return 0;
263        } else {
264            DPRINTF(StoreSet, "Inst %#x with index %i and SSID %i had LFST "
265                    "inum of %i\n", PC, index, inst_SSID, LFST[inst_SSID]);
266
267            return LFST[inst_SSID];
268        }
269    }
270}
271
272void
273StoreSet::issued(Addr issued_PC, InstSeqNum issued_seq_num, bool is_store)
274{
275    // This only is updated upon a store being issued.
276    if (!is_store) {
277        return;
278    }
279
280    int index = calcIndex(issued_PC);
281
282    int store_SSID;
283
284    assert(index < SSITSize);
285
286    SeqNumMapIt store_list_it = storeList.find(issued_seq_num);
287
288    if (store_list_it != storeList.end()) {
289        storeList.erase(store_list_it);
290    }
291
292    // Make sure the SSIT still has a valid entry for the issued store.
293    if (!validSSIT[index]) {
294        return;
295    }
296
297    store_SSID = SSIT[index];
298
299    assert(store_SSID < LFSTSize);
300
301    // If the last fetched store in the store set refers to the store that
302    // was just issued, then invalidate the entry.
303    if (validLFST[store_SSID] && LFST[store_SSID] == issued_seq_num) {
304        DPRINTF(StoreSet, "StoreSet: store invalidated itself in LFST.\n");
305        validLFST[store_SSID] = false;
306    }
307}
308
309void
310StoreSet::squash(InstSeqNum squashed_num, ThreadID tid)
311{
312    DPRINTF(StoreSet, "StoreSet: Squashing until inum %i\n",
313            squashed_num);
314
315    int idx;
316    SeqNumMapIt store_list_it = storeList.begin();
317
318    //@todo:Fix to only delete from correct thread
319    while (!storeList.empty()) {
320        idx = (*store_list_it).second;
321
322        if ((*store_list_it).first <= squashed_num) {
323            break;
324        }
325
326        bool younger = LFST[idx] > squashed_num;
327
328        if (validLFST[idx] && younger) {
329            DPRINTF(StoreSet, "Squashed [sn:%lli]\n", LFST[idx]);
330            validLFST[idx] = false;
331
332            storeList.erase(store_list_it++);
333        } else if (!validLFST[idx] && younger) {
334            storeList.erase(store_list_it++);
335        }
336    }
337}
338
339void
340StoreSet::clear()
341{
342    for (int i = 0; i < SSITSize; ++i) {
343        validSSIT[i] = false;
344    }
345
346    for (int i = 0; i < LFSTSize; ++i) {
347        validLFST[i] = false;
348    }
349
350    storeList.clear();
351}
352
353void
354StoreSet::dump()
355{
356    cprintf("storeList.size(): %i\n", storeList.size());
357    SeqNumMapIt store_list_it = storeList.begin();
358
359    int num = 0;
360
361    while (store_list_it != storeList.end()) {
362        cprintf("%i: [sn:%lli] SSID:%i\n",
363                num, (*store_list_it).first, (*store_list_it).second);
364        num++;
365        store_list_it++;
366    }
367}
368