store_set.cc revision 6221:58a3c04e6344 
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
36StoreSet::StoreSet(int _SSIT_size, int _LFST_size)
37    : SSITSize(_SSIT_size), LFSTSize(_LFST_size)
38{
39    DPRINTF(StoreSet, "StoreSet: Creating store set object.\n");
40    DPRINTF(StoreSet, "StoreSet: SSIT size: %i, LFST size: %i.\n",
41            SSITSize, LFSTSize);
42
43    if (!isPowerOf2(SSITSize)) {
44        fatal("Invalid SSIT size!\n");
45    }
46
47    SSIT.resize(SSITSize);
48
49    validSSIT.resize(SSITSize);
50
51    for (int i = 0; i < SSITSize; ++i)
52        validSSIT[i] = false;
53
54    if (!isPowerOf2(LFSTSize)) {
55        fatal("Invalid LFST size!\n");
56    }
57
58    LFST.resize(LFSTSize);
59
60    validLFST.resize(LFSTSize);
61
62    for (int i = 0; i < LFSTSize; ++i) {
63        validLFST[i] = false;
64        LFST[i] = 0;
65    }
66
67    indexMask = SSITSize - 1;
68
69    offsetBits = 2;
70}
71
72StoreSet::~StoreSet()
73{
74}
75
76void
77StoreSet::init(int _SSIT_size, int _LFST_size)
78{
79    SSITSize = _SSIT_size;
80    LFSTSize = _LFST_size;
81
82    DPRINTF(StoreSet, "StoreSet: Creating store set object.\n");
83    DPRINTF(StoreSet, "StoreSet: SSIT size: %i, LFST size: %i.\n",
84            SSITSize, LFSTSize);
85
86    SSIT.resize(SSITSize);
87
88    validSSIT.resize(SSITSize);
89
90    for (int i = 0; i < SSITSize; ++i)
91        validSSIT[i] = false;
92
93    LFST.resize(LFSTSize);
94
95    validLFST.resize(LFSTSize);
96
97    for (int i = 0; i < LFSTSize; ++i) {
98        validLFST[i] = false;
99        LFST[i] = 0;
100    }
101
102    indexMask = SSITSize - 1;
103
104    offsetBits = 2;
105}
106
107
108void
109StoreSet::violation(Addr store_PC, Addr load_PC)
110{
111    int load_index = calcIndex(load_PC);
112    int store_index = calcIndex(store_PC);
113
114    assert(load_index < SSITSize && store_index < SSITSize);
115
116    bool valid_load_SSID = validSSIT[load_index];
117    bool valid_store_SSID = validSSIT[store_index];
118
119    if (!valid_load_SSID && !valid_store_SSID) {
120        // Calculate a new SSID here.
121        SSID new_set = calcSSID(load_PC);
122
123        validSSIT[load_index] = true;
124
125        SSIT[load_index] = new_set;
126
127        validSSIT[store_index] = true;
128
129        SSIT[store_index] = new_set;
130
131        assert(new_set < LFSTSize);
132
133        DPRINTF(StoreSet, "StoreSet: Neither load nor store had a valid "
134                "storeset, creating a new one: %i for load %#x, store %#x\n",
135                new_set, load_PC, store_PC);
136    } else if (valid_load_SSID && !valid_store_SSID) {
137        SSID load_SSID = SSIT[load_index];
138
139        validSSIT[store_index] = true;
140
141        SSIT[store_index] = load_SSID;
142
143        assert(load_SSID < LFSTSize);
144
145        DPRINTF(StoreSet, "StoreSet: Load had a valid store set.  Adding "
146                "store to that set: %i for load %#x, store %#x\n",
147                load_SSID, load_PC, store_PC);
148    } else if (!valid_load_SSID && valid_store_SSID) {
149        SSID store_SSID = SSIT[store_index];
150
151        validSSIT[load_index] = true;
152
153        SSIT[load_index] = store_SSID;
154
155        DPRINTF(StoreSet, "StoreSet: Store had a valid store set: %i for "
156                "load %#x, store %#x\n",
157                store_SSID, load_PC, store_PC);
158    } else {
159        SSID load_SSID = SSIT[load_index];
160        SSID store_SSID = SSIT[store_index];
161
162        assert(load_SSID < LFSTSize && store_SSID < LFSTSize);
163
164        // The store set with the lower number wins
165        if (store_SSID > load_SSID) {
166            SSIT[store_index] = load_SSID;
167
168            DPRINTF(StoreSet, "StoreSet: Load had smaller store set: %i; "
169                    "for load %#x, store %#x\n",
170                    load_SSID, load_PC, store_PC);
171        } else {
172            SSIT[load_index] = store_SSID;
173
174            DPRINTF(StoreSet, "StoreSet: Store had smaller store set: %i; "
175                    "for load %#x, store %#x\n",
176                    store_SSID, load_PC, store_PC);
177        }
178    }
179}
180
181void
182StoreSet::insertLoad(Addr load_PC, InstSeqNum load_seq_num)
183{
184    // Does nothing.
185    return;
186}
187
188void
189StoreSet::insertStore(Addr store_PC, InstSeqNum store_seq_num, ThreadID tid)
190{
191    int index = calcIndex(store_PC);
192
193    int store_SSID;
194
195    assert(index < SSITSize);
196
197    if (!validSSIT[index]) {
198        // Do nothing if there's no valid entry.
199        return;
200    } else {
201        store_SSID = SSIT[index];
202
203        assert(store_SSID < LFSTSize);
204
205        // Update the last store that was fetched with the current one.
206        LFST[store_SSID] = store_seq_num;
207
208        validLFST[store_SSID] = 1;
209
210        storeList[store_seq_num] = store_SSID;
211
212        DPRINTF(StoreSet, "Store %#x updated the LFST, SSID: %i\n",
213                store_PC, store_SSID);
214    }
215}
216
217InstSeqNum
218StoreSet::checkInst(Addr PC)
219{
220    int index = calcIndex(PC);
221
222    int inst_SSID;
223
224    assert(index < SSITSize);
225
226    if (!validSSIT[index]) {
227        DPRINTF(StoreSet, "Inst %#x with index %i had no SSID\n",
228                PC, index);
229
230        // Return 0 if there's no valid entry.
231        return 0;
232    } else {
233        inst_SSID = SSIT[index];
234
235        assert(inst_SSID < LFSTSize);
236
237        if (!validLFST[inst_SSID]) {
238
239            DPRINTF(StoreSet, "Inst %#x with index %i and SSID %i had no "
240                    "dependency\n", PC, index, inst_SSID);
241
242            return 0;
243        } else {
244            DPRINTF(StoreSet, "Inst %#x with index %i and SSID %i had LFST "
245                    "inum of %i\n", PC, index, inst_SSID, LFST[inst_SSID]);
246
247            return LFST[inst_SSID];
248        }
249    }
250}
251
252void
253StoreSet::issued(Addr issued_PC, InstSeqNum issued_seq_num, bool is_store)
254{
255    // This only is updated upon a store being issued.
256    if (!is_store) {
257        return;
258    }
259
260    int index = calcIndex(issued_PC);
261
262    int store_SSID;
263
264    assert(index < SSITSize);
265
266    SeqNumMapIt store_list_it = storeList.find(issued_seq_num);
267
268    if (store_list_it != storeList.end()) {
269        storeList.erase(store_list_it);
270    }
271
272    // Make sure the SSIT still has a valid entry for the issued store.
273    if (!validSSIT[index]) {
274        return;
275    }
276
277    store_SSID = SSIT[index];
278
279    assert(store_SSID < LFSTSize);
280
281    // If the last fetched store in the store set refers to the store that
282    // was just issued, then invalidate the entry.
283    if (validLFST[store_SSID] && LFST[store_SSID] == issued_seq_num) {
284        DPRINTF(StoreSet, "StoreSet: store invalidated itself in LFST.\n");
285        validLFST[store_SSID] = false;
286    }
287}
288
289void
290StoreSet::squash(InstSeqNum squashed_num, ThreadID tid)
291{
292    DPRINTF(StoreSet, "StoreSet: Squashing until inum %i\n",
293            squashed_num);
294
295    int idx;
296    SeqNumMapIt store_list_it = storeList.begin();
297
298    //@todo:Fix to only delete from correct thread
299    while (!storeList.empty()) {
300        idx = (*store_list_it).second;
301
302        if ((*store_list_it).first <= squashed_num) {
303            break;
304        }
305
306        bool younger = LFST[idx] > squashed_num;
307
308        if (validLFST[idx] && younger) {
309            DPRINTF(StoreSet, "Squashed [sn:%lli]\n", LFST[idx]);
310            validLFST[idx] = false;
311
312            storeList.erase(store_list_it++);
313        } else if (!validLFST[idx] && younger) {
314            storeList.erase(store_list_it++);
315        }
316    }
317}
318
319void
320StoreSet::clear()
321{
322    for (int i = 0; i < SSITSize; ++i) {
323        validSSIT[i] = false;
324    }
325
326    for (int i = 0; i < LFSTSize; ++i) {
327        validLFST[i] = false;
328    }
329
330    storeList.clear();
331}
332
333void
334StoreSet::dump()
335{
336    cprintf("storeList.size(): %i\n", storeList.size());
337    SeqNumMapIt store_list_it = storeList.begin();
338
339    int num = 0;
340
341    while (store_list_it != storeList.end()) {
342        cprintf("%i: [sn:%lli] SSID:%i\n",
343                num, (*store_list_it).first, (*store_list_it).second);
344        num++;
345        store_list_it++;
346    }
347}
348