store_set.cc revision 8232:b28d06a175be 
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(int _SSIT_size, int _LFST_size)
38    : 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
73StoreSet::~StoreSet()
74{
75}
76
77void
78StoreSet::init(int _SSIT_size, int _LFST_size)
79{
80    SSITSize = _SSIT_size;
81    LFSTSize = _LFST_size;
82
83    DPRINTF(StoreSet, "StoreSet: Creating store set object.\n");
84    DPRINTF(StoreSet, "StoreSet: SSIT size: %i, LFST size: %i.\n",
85            SSITSize, LFSTSize);
86
87    SSIT.resize(SSITSize);
88
89    validSSIT.resize(SSITSize);
90
91    for (int i = 0; i < SSITSize; ++i)
92        validSSIT[i] = false;
93
94    LFST.resize(LFSTSize);
95
96    validLFST.resize(LFSTSize);
97
98    for (int i = 0; i < LFSTSize; ++i) {
99        validLFST[i] = false;
100        LFST[i] = 0;
101    }
102
103    indexMask = SSITSize - 1;
104
105    offsetBits = 2;
106}
107
108
109void
110StoreSet::violation(Addr store_PC, Addr load_PC)
111{
112    int load_index = calcIndex(load_PC);
113    int store_index = calcIndex(store_PC);
114
115    assert(load_index < SSITSize && store_index < SSITSize);
116
117    bool valid_load_SSID = validSSIT[load_index];
118    bool valid_store_SSID = validSSIT[store_index];
119
120    if (!valid_load_SSID && !valid_store_SSID) {
121        // Calculate a new SSID here.
122        SSID new_set = calcSSID(load_PC);
123
124        validSSIT[load_index] = true;
125
126        SSIT[load_index] = new_set;
127
128        validSSIT[store_index] = true;
129
130        SSIT[store_index] = new_set;
131
132        assert(new_set < LFSTSize);
133
134        DPRINTF(StoreSet, "StoreSet: Neither load nor store had a valid "
135                "storeset, creating a new one: %i for load %#x, store %#x\n",
136                new_set, load_PC, store_PC);
137    } else if (valid_load_SSID && !valid_store_SSID) {
138        SSID load_SSID = SSIT[load_index];
139
140        validSSIT[store_index] = true;
141
142        SSIT[store_index] = load_SSID;
143
144        assert(load_SSID < LFSTSize);
145
146        DPRINTF(StoreSet, "StoreSet: Load had a valid store set.  Adding "
147                "store to that set: %i for load %#x, store %#x\n",
148                load_SSID, load_PC, store_PC);
149    } else if (!valid_load_SSID && valid_store_SSID) {
150        SSID store_SSID = SSIT[store_index];
151
152        validSSIT[load_index] = true;
153
154        SSIT[load_index] = store_SSID;
155
156        DPRINTF(StoreSet, "StoreSet: Store had a valid store set: %i for "
157                "load %#x, store %#x\n",
158                store_SSID, load_PC, store_PC);
159    } else {
160        SSID load_SSID = SSIT[load_index];
161        SSID store_SSID = SSIT[store_index];
162
163        assert(load_SSID < LFSTSize && store_SSID < LFSTSize);
164
165        // The store set with the lower number wins
166        if (store_SSID > load_SSID) {
167            SSIT[store_index] = load_SSID;
168
169            DPRINTF(StoreSet, "StoreSet: Load had smaller store set: %i; "
170                    "for load %#x, store %#x\n",
171                    load_SSID, load_PC, store_PC);
172        } else {
173            SSIT[load_index] = store_SSID;
174
175            DPRINTF(StoreSet, "StoreSet: Store had smaller store set: %i; "
176                    "for load %#x, store %#x\n",
177                    store_SSID, load_PC, store_PC);
178        }
179    }
180}
181
182void
183StoreSet::insertLoad(Addr load_PC, InstSeqNum load_seq_num)
184{
185    // Does nothing.
186    return;
187}
188
189void
190StoreSet::insertStore(Addr store_PC, InstSeqNum store_seq_num, ThreadID tid)
191{
192    int index = calcIndex(store_PC);
193
194    int store_SSID;
195
196    assert(index < SSITSize);
197
198    if (!validSSIT[index]) {
199        // Do nothing if there's no valid entry.
200        return;
201    } else {
202        store_SSID = SSIT[index];
203
204        assert(store_SSID < LFSTSize);
205
206        // Update the last store that was fetched with the current one.
207        LFST[store_SSID] = store_seq_num;
208
209        validLFST[store_SSID] = 1;
210
211        storeList[store_seq_num] = store_SSID;
212
213        DPRINTF(StoreSet, "Store %#x updated the LFST, SSID: %i\n",
214                store_PC, store_SSID);
215    }
216}
217
218InstSeqNum
219StoreSet::checkInst(Addr PC)
220{
221    int index = calcIndex(PC);
222
223    int inst_SSID;
224
225    assert(index < SSITSize);
226
227    if (!validSSIT[index]) {
228        DPRINTF(StoreSet, "Inst %#x with index %i had no SSID\n",
229                PC, index);
230
231        // Return 0 if there's no valid entry.
232        return 0;
233    } else {
234        inst_SSID = SSIT[index];
235
236        assert(inst_SSID < LFSTSize);
237
238        if (!validLFST[inst_SSID]) {
239
240            DPRINTF(StoreSet, "Inst %#x with index %i and SSID %i had no "
241                    "dependency\n", PC, index, inst_SSID);
242
243            return 0;
244        } else {
245            DPRINTF(StoreSet, "Inst %#x with index %i and SSID %i had LFST "
246                    "inum of %i\n", PC, index, inst_SSID, LFST[inst_SSID]);
247
248            return LFST[inst_SSID];
249        }
250    }
251}
252
253void
254StoreSet::issued(Addr issued_PC, InstSeqNum issued_seq_num, bool is_store)
255{
256    // This only is updated upon a store being issued.
257    if (!is_store) {
258        return;
259    }
260
261    int index = calcIndex(issued_PC);
262
263    int store_SSID;
264
265    assert(index < SSITSize);
266
267    SeqNumMapIt store_list_it = storeList.find(issued_seq_num);
268
269    if (store_list_it != storeList.end()) {
270        storeList.erase(store_list_it);
271    }
272
273    // Make sure the SSIT still has a valid entry for the issued store.
274    if (!validSSIT[index]) {
275        return;
276    }
277
278    store_SSID = SSIT[index];
279
280    assert(store_SSID < LFSTSize);
281
282    // If the last fetched store in the store set refers to the store that
283    // was just issued, then invalidate the entry.
284    if (validLFST[store_SSID] && LFST[store_SSID] == issued_seq_num) {
285        DPRINTF(StoreSet, "StoreSet: store invalidated itself in LFST.\n");
286        validLFST[store_SSID] = false;
287    }
288}
289
290void
291StoreSet::squash(InstSeqNum squashed_num, ThreadID tid)
292{
293    DPRINTF(StoreSet, "StoreSet: Squashing until inum %i\n",
294            squashed_num);
295
296    int idx;
297    SeqNumMapIt store_list_it = storeList.begin();
298
299    //@todo:Fix to only delete from correct thread
300    while (!storeList.empty()) {
301        idx = (*store_list_it).second;
302
303        if ((*store_list_it).first <= squashed_num) {
304            break;
305        }
306
307        bool younger = LFST[idx] > squashed_num;
308
309        if (validLFST[idx] && younger) {
310            DPRINTF(StoreSet, "Squashed [sn:%lli]\n", LFST[idx]);
311            validLFST[idx] = false;
312
313            storeList.erase(store_list_it++);
314        } else if (!validLFST[idx] && younger) {
315            storeList.erase(store_list_it++);
316        }
317    }
318}
319
320void
321StoreSet::clear()
322{
323    for (int i = 0; i < SSITSize; ++i) {
324        validSSIT[i] = false;
325    }
326
327    for (int i = 0; i < LFSTSize; ++i) {
328        validLFST[i] = false;
329    }
330
331    storeList.clear();
332}
333
334void
335StoreSet::dump()
336{
337    cprintf("storeList.size(): %i\n", storeList.size());
338    SeqNumMapIt store_list_it = storeList.begin();
339
340    int num = 0;
341
342    while (store_list_it != storeList.end()) {
343        cprintf("%i: [sn:%lli] SSID:%i\n",
344                num, (*store_list_it).first, (*store_list_it).second);
345        num++;
346        store_list_it++;
347    }
348}
349