store_set.cc revision 2674:6d4afef73a20 
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/trace.hh"
33#include "cpu/o3/store_set.hh"
34
35StoreSet::StoreSet(int _SSIT_size, int _LFST_size)
36    : SSITSize(_SSIT_size), LFSTSize(_LFST_size)
37{
38    DPRINTF(StoreSet, "StoreSet: Creating store set object.\n");
39    DPRINTF(StoreSet, "StoreSet: SSIT size: %i, LFST size: %i.\n",
40            SSITSize, LFSTSize);
41
42    if (!isPowerOf2(SSITSize)) {
43        fatal("Invalid SSIT size!\n");
44    }
45
46    SSIT.resize(SSITSize);
47
48    validSSIT.resize(SSITSize);
49
50    for (int i = 0; i < SSITSize; ++i)
51        validSSIT[i] = false;
52
53    if (!isPowerOf2(LFSTSize)) {
54        fatal("Invalid LFST size!\n");
55    }
56
57    LFST.resize(LFSTSize);
58
59    validLFST.resize(LFSTSize);
60
61    for (int i = 0; i < LFSTSize; ++i) {
62        validLFST[i] = false;
63        LFST[i] = 0;
64    }
65
66    indexMask = SSITSize - 1;
67
68    offsetBits = 2;
69}
70
71StoreSet::~StoreSet()
72{
73}
74
75void
76StoreSet::init(int _SSIT_size, int _LFST_size)
77{
78    SSITSize = _SSIT_size;
79    LFSTSize = _LFST_size;
80
81    DPRINTF(StoreSet, "StoreSet: Creating store set object.\n");
82    DPRINTF(StoreSet, "StoreSet: SSIT size: %i, LFST size: %i.\n",
83            SSITSize, LFSTSize);
84
85    SSIT.resize(SSITSize);
86
87    validSSIT.resize(SSITSize);
88
89    for (int i = 0; i < SSITSize; ++i)
90        validSSIT[i] = false;
91
92    LFST.resize(LFSTSize);
93
94    validLFST.resize(LFSTSize);
95
96    for (int i = 0; i < LFSTSize; ++i) {
97        validLFST[i] = false;
98        LFST[i] = 0;
99    }
100
101    indexMask = SSITSize - 1;
102
103    offsetBits = 2;
104}
105
106
107void
108StoreSet::violation(Addr store_PC, Addr load_PC)
109{
110    int load_index = calcIndex(load_PC);
111    int store_index = calcIndex(store_PC);
112
113    assert(load_index < SSITSize && store_index < SSITSize);
114
115    bool valid_load_SSID = validSSIT[load_index];
116    bool valid_store_SSID = validSSIT[store_index];
117
118    if (!valid_load_SSID && !valid_store_SSID) {
119        // Calculate a new SSID here.
120        SSID new_set = calcSSID(load_PC);
121
122        validSSIT[load_index] = true;
123
124        SSIT[load_index] = new_set;
125
126        validSSIT[store_index] = true;
127
128        SSIT[store_index] = new_set;
129
130        assert(new_set < LFSTSize);
131
132        DPRINTF(StoreSet, "StoreSet: Neither load nor store had a valid "
133                "storeset, creating a new one: %i for load %#x, store %#x\n",
134                new_set, load_PC, store_PC);
135    } else if (valid_load_SSID && !valid_store_SSID) {
136        SSID load_SSID = SSIT[load_index];
137
138        validSSIT[store_index] = true;
139
140        SSIT[store_index] = load_SSID;
141
142        assert(load_SSID < LFSTSize);
143
144        DPRINTF(StoreSet, "StoreSet: Load had a valid store set.  Adding "
145                "store to that set: %i for load %#x, store %#x\n",
146                load_SSID, load_PC, store_PC);
147    } else if (!valid_load_SSID && valid_store_SSID) {
148        SSID store_SSID = SSIT[store_index];
149
150        validSSIT[load_index] = true;
151
152        SSIT[load_index] = store_SSID;
153
154        DPRINTF(StoreSet, "StoreSet: Store had a valid store set: %i for "
155                "load %#x, store %#x\n",
156                store_SSID, load_PC, store_PC);
157    } else {
158        SSID load_SSID = SSIT[load_index];
159        SSID store_SSID = SSIT[store_index];
160
161        assert(load_SSID < LFSTSize && store_SSID < LFSTSize);
162
163        // The store set with the lower number wins
164        if (store_SSID > load_SSID) {
165            SSIT[store_index] = load_SSID;
166
167            DPRINTF(StoreSet, "StoreSet: Load had smaller store set: %i; "
168                    "for load %#x, store %#x\n",
169                    load_SSID, load_PC, store_PC);
170        } else {
171            SSIT[load_index] = store_SSID;
172
173            DPRINTF(StoreSet, "StoreSet: Store had smaller store set: %i; "
174                    "for load %#x, store %#x\n",
175                    store_SSID, load_PC, store_PC);
176        }
177    }
178}
179
180void
181StoreSet::insertLoad(Addr load_PC, InstSeqNum load_seq_num)
182{
183    // Does nothing.
184    return;
185}
186
187void
188StoreSet::insertStore(Addr store_PC, InstSeqNum store_seq_num,
189                      unsigned 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, unsigned 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