store_set.cc revision 2348 
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
29#include "base/intmath.hh"
30#include "base/trace.hh"
31#include "cpu/o3/store_set.hh"
32
33StoreSet::StoreSet(int _SSIT_size, int _LFST_size)
34    : SSITSize(_SSIT_size), LFSTSize(_LFST_size)
35{
36    DPRINTF(StoreSet, "StoreSet: Creating store set object.\n");
37    DPRINTF(StoreSet, "StoreSet: SSIT size: %i, LFST size: %i.\n",
38            SSITSize, LFSTSize);
39
40    if (!isPowerOf2(SSITSize)) {
41        fatal("Invalid SSIT size!\n");
42    }
43
44    SSIT.resize(SSITSize);
45
46    validSSIT.resize(SSITSize);
47
48    for (int i = 0; i < SSITSize; ++i)
49        validSSIT[i] = false;
50
51    if (!isPowerOf2(LFSTSize)) {
52        fatal("Invalid LFST size!\n");
53    }
54
55    LFST.resize(LFSTSize);
56
57    validLFST.resize(LFSTSize);
58
59    for (int i = 0; i < LFSTSize; ++i) {
60        validLFST[i] = false;
61        LFST[i] = 0;
62    }
63
64    indexMask = SSITSize - 1;
65
66    offsetBits = 2;
67}
68
69StoreSet::~StoreSet()
70{
71}
72
73void
74StoreSet::init(int _SSIT_size, int _LFST_size)
75{
76    SSITSize = _SSIT_size;
77    LFSTSize = _LFST_size;
78
79    DPRINTF(StoreSet, "StoreSet: Creating store set object.\n");
80    DPRINTF(StoreSet, "StoreSet: SSIT size: %i, LFST size: %i.\n",
81            SSITSize, LFSTSize);
82
83    SSIT.resize(SSITSize);
84
85    validSSIT.resize(SSITSize);
86
87    for (int i = 0; i < SSITSize; ++i)
88        validSSIT[i] = false;
89
90    LFST.resize(LFSTSize);
91
92    validLFST.resize(LFSTSize);
93
94    for (int i = 0; i < LFSTSize; ++i) {
95        validLFST[i] = false;
96        LFST[i] = 0;
97    }
98
99    indexMask = SSITSize - 1;
100
101    offsetBits = 2;
102}
103
104
105void
106StoreSet::violation(Addr store_PC, Addr load_PC)
107{
108    int load_index = calcIndex(load_PC);
109    int store_index = calcIndex(store_PC);
110
111    assert(load_index < SSITSize && store_index < SSITSize);
112
113    bool valid_load_SSID = validSSIT[load_index];
114    bool valid_store_SSID = validSSIT[store_index];
115
116    if (!valid_load_SSID && !valid_store_SSID) {
117        // Calculate a new SSID here.
118        SSID new_set = calcSSID(load_PC);
119
120        validSSIT[load_index] = true;
121
122        SSIT[load_index] = new_set;
123
124        validSSIT[store_index] = true;
125
126        SSIT[store_index] = new_set;
127
128        assert(new_set < LFSTSize);
129
130        DPRINTF(StoreSet, "StoreSet: Neither load nor store had a valid "
131                "storeset, creating a new one: %i for load %#x, store %#x\n",
132                new_set, load_PC, store_PC);
133    } else if (valid_load_SSID && !valid_store_SSID) {
134        SSID load_SSID = SSIT[load_index];
135
136        validSSIT[store_index] = true;
137
138        SSIT[store_index] = load_SSID;
139
140        assert(load_SSID < LFSTSize);
141
142        DPRINTF(StoreSet, "StoreSet: Load had a valid store set.  Adding "
143                "store to that set: %i for load %#x, store %#x\n",
144                load_SSID, load_PC, store_PC);
145    } else if (!valid_load_SSID && valid_store_SSID) {
146        SSID store_SSID = SSIT[store_index];
147
148        validSSIT[load_index] = true;
149
150        SSIT[load_index] = store_SSID;
151
152        DPRINTF(StoreSet, "StoreSet: Store had a valid store set: %i for "
153                "load %#x, store %#x\n",
154                store_SSID, load_PC, store_PC);
155    } else {
156        SSID load_SSID = SSIT[load_index];
157        SSID store_SSID = SSIT[store_index];
158
159        assert(load_SSID < LFSTSize && store_SSID < LFSTSize);
160
161        // The store set with the lower number wins
162        if (store_SSID > load_SSID) {
163            SSIT[store_index] = load_SSID;
164
165            DPRINTF(StoreSet, "StoreSet: Load had smaller store set: %i; "
166                    "for load %#x, store %#x\n",
167                    load_SSID, load_PC, store_PC);
168        } else {
169            SSIT[load_index] = store_SSID;
170
171            DPRINTF(StoreSet, "StoreSet: Store had smaller store set: %i; "
172                    "for load %#x, store %#x\n",
173                    store_SSID, load_PC, store_PC);
174        }
175    }
176}
177
178void
179StoreSet::insertLoad(Addr load_PC, InstSeqNum load_seq_num)
180{
181    // Does nothing.
182    return;
183}
184
185void
186StoreSet::insertStore(Addr store_PC, InstSeqNum store_seq_num,
187                      unsigned tid)
188{
189    int index = calcIndex(store_PC);
190
191    int store_SSID;
192
193    assert(index < SSITSize);
194
195    if (!validSSIT[index]) {
196        // Do nothing if there's no valid entry.
197        return;
198    } else {
199        store_SSID = SSIT[index];
200
201        assert(store_SSID < LFSTSize);
202
203        // Update the last store that was fetched with the current one.
204        LFST[store_SSID] = store_seq_num;
205
206        validLFST[store_SSID] = 1;
207
208        storeList[store_seq_num] = store_SSID;
209
210        DPRINTF(StoreSet, "Store %#x updated the LFST, SSID: %i\n",
211                store_PC, store_SSID);
212    }
213}
214
215InstSeqNum
216StoreSet::checkInst(Addr PC)
217{
218    int index = calcIndex(PC);
219
220    int inst_SSID;
221
222    assert(index < SSITSize);
223
224    if (!validSSIT[index]) {
225        DPRINTF(StoreSet, "Inst %#x with index %i had no SSID\n",
226                PC, index);
227
228        // Return 0 if there's no valid entry.
229        return 0;
230    } else {
231        inst_SSID = SSIT[index];
232
233        assert(inst_SSID < LFSTSize);
234
235        if (!validLFST[inst_SSID]) {
236
237            DPRINTF(StoreSet, "Inst %#x with index %i and SSID %i had no "
238                    "dependency\n", PC, index, inst_SSID);
239
240            return 0;
241        } else {
242            DPRINTF(StoreSet, "Inst %#x with index %i and SSID %i had LFST "
243                    "inum of %i\n", PC, index, inst_SSID, LFST[inst_SSID]);
244
245            return LFST[inst_SSID];
246        }
247    }
248}
249
250void
251StoreSet::issued(Addr issued_PC, InstSeqNum issued_seq_num, bool is_store)
252{
253    // This only is updated upon a store being issued.
254    if (!is_store) {
255        return;
256    }
257
258    int index = calcIndex(issued_PC);
259
260    int store_SSID;
261
262    assert(index < SSITSize);
263
264    SeqNumMapIt store_list_it = storeList.find(issued_seq_num);
265
266    if (store_list_it != storeList.end()) {
267        storeList.erase(store_list_it);
268    }
269
270    // Make sure the SSIT still has a valid entry for the issued store.
271    if (!validSSIT[index]) {
272        return;
273    }
274
275    store_SSID = SSIT[index];
276
277    assert(store_SSID < LFSTSize);
278
279    // If the last fetched store in the store set refers to the store that
280    // was just issued, then invalidate the entry.
281    if (validLFST[store_SSID] && LFST[store_SSID] == issued_seq_num) {
282        DPRINTF(StoreSet, "StoreSet: store invalidated itself in LFST.\n");
283        validLFST[store_SSID] = false;
284    }
285}
286
287void
288StoreSet::squash(InstSeqNum squashed_num, unsigned tid)
289{
290    DPRINTF(StoreSet, "StoreSet: Squashing until inum %i\n",
291            squashed_num);
292
293    int idx;
294    SeqNumMapIt store_list_it = storeList.begin();
295
296    //@todo:Fix to only delete from correct thread
297    while (!storeList.empty()) {
298        idx = (*store_list_it).second;
299
300        if ((*store_list_it).first <= squashed_num) {
301            break;
302        }
303
304        bool younger = LFST[idx] > squashed_num;
305
306        if (validLFST[idx] && younger) {
307            DPRINTF(StoreSet, "Squashed [sn:%lli]\n", LFST[idx]);
308            validLFST[idx] = false;
309
310            storeList.erase(store_list_it++);
311        } else if (!validLFST[idx] && younger) {
312            storeList.erase(store_list_it++);
313        }
314    }
315}
316
317void
318StoreSet::clear()
319{
320    for (int i = 0; i < SSITSize; ++i) {
321        validSSIT[i] = false;
322    }
323
324    for (int i = 0; i < LFSTSize; ++i) {
325        validLFST[i] = false;
326    }
327
328    storeList.clear();
329}
330
331void
332StoreSet::dump()
333{
334    cprintf("storeList.size(): %i\n", storeList.size());
335    SeqNumMapIt store_list_it = storeList.begin();
336
337    int num = 0;
338
339    while (store_list_it != storeList.end()) {
340        cprintf("%i: [sn:%lli] SSID:%i\n",
341                num, (*store_list_it).first, (*store_list_it).second);
342        num++;
343        store_list_it++;
344    }
345}
346