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#ifndef __CPU_O3_ROB_HH__
32#define __CPU_O3_ROB_HH__
33
34#include <string>
35#include <utility>
36#include <vector>
37
38/**
39 * ROB class. The ROB is largely what drives squashing.
40 */
41template <class Impl>
42class ROB
43{
44 protected:
45 typedef TheISA::RegIndex RegIndex;
46 public:
47 //Typedefs from the Impl.
48 typedef typename Impl::FullCPU FullCPU;
49 typedef typename Impl::DynInstPtr DynInstPtr;
50
51 typedef std::pair<RegIndex, PhysRegIndex> UnmapInfo;
52 typedef typename std::list<DynInstPtr>::iterator InstIt;
53
54 /** Possible ROB statuses. */
55 enum Status {
56 Running,
57 Idle,
58 ROBSquashing
59 };
60
61 /** SMT ROB Sharing Policy */
62 enum ROBPolicy{
63 Dynamic,
64 Partitioned,
65 Threshold
66 };
67
68 private:
69 /** Per-thread ROB status. */
70 Status robStatus[Impl::MaxThreads];
71
72 /** ROB resource sharing policy for SMT mode. */
73 ROBPolicy robPolicy;
74
75 public:
76 /** ROB constructor.
77 * @param _numEntries Number of entries in ROB.
78 * @param _squashWidth Number of instructions that can be squashed in a
79 * single cycle.
80 * @param _smtROBPolicy ROB Partitioning Scheme for SMT.
81 * @param _smtROBThreshold Max Resources(by %) a thread can have in the ROB.
82 * @param _numThreads The number of active threads.
83 */
84 ROB(unsigned _numEntries, unsigned _squashWidth, std::string smtROBPolicy,
85 unsigned _smtROBThreshold, unsigned _numThreads);
86
87 std::string name() const;
88
89 /** Function to set the CPU pointer, necessary due to which object the ROB
90 * is created within.
91 * @param cpu_ptr Pointer to the implementation specific full CPU object.
92 */
93 void setCPU(FullCPU *cpu_ptr);
94
95 /** Sets pointer to the list of active threads.
96 * @param at_ptr Pointer to the list of active threads.
97 */
98 void setActiveThreads(std::list<unsigned>* at_ptr);
99
| 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#ifndef __CPU_O3_ROB_HH__
32#define __CPU_O3_ROB_HH__
33
34#include <string>
35#include <utility>
36#include <vector>
37
38/**
39 * ROB class. The ROB is largely what drives squashing.
40 */
41template <class Impl>
42class ROB
43{
44 protected:
45 typedef TheISA::RegIndex RegIndex;
46 public:
47 //Typedefs from the Impl.
48 typedef typename Impl::FullCPU FullCPU;
49 typedef typename Impl::DynInstPtr DynInstPtr;
50
51 typedef std::pair<RegIndex, PhysRegIndex> UnmapInfo;
52 typedef typename std::list<DynInstPtr>::iterator InstIt;
53
54 /** Possible ROB statuses. */
55 enum Status {
56 Running,
57 Idle,
58 ROBSquashing
59 };
60
61 /** SMT ROB Sharing Policy */
62 enum ROBPolicy{
63 Dynamic,
64 Partitioned,
65 Threshold
66 };
67
68 private:
69 /** Per-thread ROB status. */
70 Status robStatus[Impl::MaxThreads];
71
72 /** ROB resource sharing policy for SMT mode. */
73 ROBPolicy robPolicy;
74
75 public:
76 /** ROB constructor.
77 * @param _numEntries Number of entries in ROB.
78 * @param _squashWidth Number of instructions that can be squashed in a
79 * single cycle.
80 * @param _smtROBPolicy ROB Partitioning Scheme for SMT.
81 * @param _smtROBThreshold Max Resources(by %) a thread can have in the ROB.
82 * @param _numThreads The number of active threads.
83 */
84 ROB(unsigned _numEntries, unsigned _squashWidth, std::string smtROBPolicy,
85 unsigned _smtROBThreshold, unsigned _numThreads);
86
87 std::string name() const;
88
89 /** Function to set the CPU pointer, necessary due to which object the ROB
90 * is created within.
91 * @param cpu_ptr Pointer to the implementation specific full CPU object.
92 */
93 void setCPU(FullCPU *cpu_ptr);
94
95 /** Sets pointer to the list of active threads.
96 * @param at_ptr Pointer to the list of active threads.
97 */
98 void setActiveThreads(std::list<unsigned>* at_ptr);
99
|
102 void takeOverFrom();
103
104 /** Function to insert an instruction into the ROB. Note that whatever
105 * calls this function must ensure that there is enough space within the
106 * ROB for the new instruction.
107 * @param inst The instruction being inserted into the ROB.
108 */
109 void insertInst(DynInstPtr &inst);
110
111 /** Returns pointer to the head instruction within the ROB. There is
112 * no guarantee as to the return value if the ROB is empty.
113 * @retval Pointer to the DynInst that is at the head of the ROB.
114 */
115// DynInstPtr readHeadInst();
116
117 /** Returns a pointer to the head instruction of a specific thread within
118 * the ROB.
119 * @return Pointer to the DynInst that is at the head of the ROB.
120 */
121 DynInstPtr readHeadInst(unsigned tid);
122
123 /** Returns pointer to the tail instruction within the ROB. There is
124 * no guarantee as to the return value if the ROB is empty.
125 * @retval Pointer to the DynInst that is at the tail of the ROB.
126 */
127// DynInstPtr readTailInst();
128
129 /** Returns a pointer to the tail instruction of a specific thread within
130 * the ROB.
131 * @return Pointer to the DynInst that is at the tail of the ROB.
132 */
133 DynInstPtr readTailInst(unsigned tid);
134
135 /** Retires the head instruction, removing it from the ROB. */
136// void retireHead();
137
138 /** Retires the head instruction of a specific thread, removing it from the
139 * ROB.
140 */
141 void retireHead(unsigned tid);
142
143 /** Is the oldest instruction across all threads ready. */
144// bool isHeadReady();
145
146 /** Is the oldest instruction across a particular thread ready. */
147 bool isHeadReady(unsigned tid);
148
149 /** Is there any commitable head instruction across all threads ready. */
150 bool canCommit();
151
152 /** Re-adjust ROB partitioning. */
153 void resetEntries();
154
155 /** Number of entries needed For 'num_threads' amount of threads. */
156 int entryAmount(int num_threads);
157
158 /** Returns the number of total free entries in the ROB. */
159 unsigned numFreeEntries();
160
161 /** Returns the number of free entries in a specific ROB paritition. */
162 unsigned numFreeEntries(unsigned tid);
163
164 /** Returns the maximum number of entries for a specific thread. */
165 unsigned getMaxEntries(unsigned tid)
166 { return maxEntries[tid]; }
167
168 /** Returns the number of entries being used by a specific thread. */
169 unsigned getThreadEntries(unsigned tid)
170 { return threadEntries[tid]; }
171
172 /** Returns if the ROB is full. */
173 bool isFull()
174 { return numInstsInROB == numEntries; }
175
176 /** Returns if a specific thread's partition is full. */
177 bool isFull(unsigned tid)
178 { return threadEntries[tid] == numEntries; }
179
180 /** Returns if the ROB is empty. */
181 bool isEmpty()
182 { return numInstsInROB == 0; }
183
184 /** Returns if a specific thread's partition is empty. */
185 bool isEmpty(unsigned tid)
186 { return threadEntries[tid] == 0; }
187
188 /** Executes the squash, marking squashed instructions. */
189 void doSquash(unsigned tid);
190
191 /** Squashes all instructions younger than the given sequence number for
192 * the specific thread.
193 */
194 void squash(InstSeqNum squash_num, unsigned tid);
195
196 /** Updates the head instruction with the new oldest instruction. */
197 void updateHead();
198
199 /** Updates the tail instruction with the new youngest instruction. */
200 void updateTail();
201
202 /** Reads the PC of the oldest head instruction. */
203// uint64_t readHeadPC();
204
205 /** Reads the PC of the head instruction of a specific thread. */
206// uint64_t readHeadPC(unsigned tid);
207
208 /** Reads the next PC of the oldest head instruction. */
209// uint64_t readHeadNextPC();
210
211 /** Reads the next PC of the head instruction of a specific thread. */
212// uint64_t readHeadNextPC(unsigned tid);
213
214 /** Reads the sequence number of the oldest head instruction. */
215// InstSeqNum readHeadSeqNum();
216
217 /** Reads the sequence number of the head instruction of a specific thread.
218 */
219// InstSeqNum readHeadSeqNum(unsigned tid);
220
221 /** Reads the PC of the youngest tail instruction. */
222// uint64_t readTailPC();
223
224 /** Reads the PC of the tail instruction of a specific thread. */
225// uint64_t readTailPC(unsigned tid);
226
227 /** Reads the sequence number of the youngest tail instruction. */
228// InstSeqNum readTailSeqNum();
229
230 /** Reads the sequence number of tail instruction of a specific thread. */
231// InstSeqNum readTailSeqNum(unsigned tid);
232
233 /** Checks if the ROB is still in the process of squashing instructions.
234 * @retval Whether or not the ROB is done squashing.
235 */
236 bool isDoneSquashing(unsigned tid) const
237 { return doneSquashing[tid]; }
238
239 /** Checks if the ROB is still in the process of squashing instructions for
240 * any thread.
241 */
242 bool isDoneSquashing();
243
244 /** This is more of a debugging function than anything. Use
245 * numInstsInROB to get the instructions in the ROB unless you are
246 * double checking that variable.
247 */
248 int countInsts();
249
250 /** This is more of a debugging function than anything. Use
251 * threadEntries to get the instructions in the ROB unless you are
252 * double checking that variable.
253 */
254 int countInsts(unsigned tid);
255
256 private:
257 /** Pointer to the CPU. */
258 FullCPU *cpu;
259
260 /** Active Threads in CPU */
261 std::list<unsigned>* activeThreads;
262
263 /** Number of instructions in the ROB. */
264 unsigned numEntries;
265
266 /** Entries Per Thread */
267 unsigned threadEntries[Impl::MaxThreads];
268
269 /** Max Insts a Thread Can Have in the ROB */
270 unsigned maxEntries[Impl::MaxThreads];
271
272 /** ROB List of Instructions */
273 std::list<DynInstPtr> instList[Impl::MaxThreads];
274
275 /** Number of instructions that can be squashed in a single cycle. */
276 unsigned squashWidth;
277
278 public:
279 /** Iterator pointing to the instruction which is the last instruction
280 * in the ROB. This may at times be invalid (ie when the ROB is empty),
281 * however it should never be incorrect.
282 */
283 InstIt tail;
284
285 /** Iterator pointing to the instruction which is the first instruction in
286 * in the ROB*/
287 InstIt head;
288
289 private:
290 /** Iterator used for walking through the list of instructions when
291 * squashing. Used so that there is persistent state between cycles;
292 * when squashing, the instructions are marked as squashed but not
293 * immediately removed, meaning the tail iterator remains the same before
294 * and after a squash.
295 * This will always be set to cpu->instList.end() if it is invalid.
296 */
297 InstIt squashIt[Impl::MaxThreads];
298
299 public:
300 /** Number of instructions in the ROB. */
301 int numInstsInROB;
302
| 104 void takeOverFrom();
105
106 /** Function to insert an instruction into the ROB. Note that whatever
107 * calls this function must ensure that there is enough space within the
108 * ROB for the new instruction.
109 * @param inst The instruction being inserted into the ROB.
110 */
111 void insertInst(DynInstPtr &inst);
112
113 /** Returns pointer to the head instruction within the ROB. There is
114 * no guarantee as to the return value if the ROB is empty.
115 * @retval Pointer to the DynInst that is at the head of the ROB.
116 */
117// DynInstPtr readHeadInst();
118
119 /** Returns a pointer to the head instruction of a specific thread within
120 * the ROB.
121 * @return Pointer to the DynInst that is at the head of the ROB.
122 */
123 DynInstPtr readHeadInst(unsigned tid);
124
125 /** Returns pointer to the tail instruction within the ROB. There is
126 * no guarantee as to the return value if the ROB is empty.
127 * @retval Pointer to the DynInst that is at the tail of the ROB.
128 */
129// DynInstPtr readTailInst();
130
131 /** Returns a pointer to the tail instruction of a specific thread within
132 * the ROB.
133 * @return Pointer to the DynInst that is at the tail of the ROB.
134 */
135 DynInstPtr readTailInst(unsigned tid);
136
137 /** Retires the head instruction, removing it from the ROB. */
138// void retireHead();
139
140 /** Retires the head instruction of a specific thread, removing it from the
141 * ROB.
142 */
143 void retireHead(unsigned tid);
144
145 /** Is the oldest instruction across all threads ready. */
146// bool isHeadReady();
147
148 /** Is the oldest instruction across a particular thread ready. */
149 bool isHeadReady(unsigned tid);
150
151 /** Is there any commitable head instruction across all threads ready. */
152 bool canCommit();
153
154 /** Re-adjust ROB partitioning. */
155 void resetEntries();
156
157 /** Number of entries needed For 'num_threads' amount of threads. */
158 int entryAmount(int num_threads);
159
160 /** Returns the number of total free entries in the ROB. */
161 unsigned numFreeEntries();
162
163 /** Returns the number of free entries in a specific ROB paritition. */
164 unsigned numFreeEntries(unsigned tid);
165
166 /** Returns the maximum number of entries for a specific thread. */
167 unsigned getMaxEntries(unsigned tid)
168 { return maxEntries[tid]; }
169
170 /** Returns the number of entries being used by a specific thread. */
171 unsigned getThreadEntries(unsigned tid)
172 { return threadEntries[tid]; }
173
174 /** Returns if the ROB is full. */
175 bool isFull()
176 { return numInstsInROB == numEntries; }
177
178 /** Returns if a specific thread's partition is full. */
179 bool isFull(unsigned tid)
180 { return threadEntries[tid] == numEntries; }
181
182 /** Returns if the ROB is empty. */
183 bool isEmpty()
184 { return numInstsInROB == 0; }
185
186 /** Returns if a specific thread's partition is empty. */
187 bool isEmpty(unsigned tid)
188 { return threadEntries[tid] == 0; }
189
190 /** Executes the squash, marking squashed instructions. */
191 void doSquash(unsigned tid);
192
193 /** Squashes all instructions younger than the given sequence number for
194 * the specific thread.
195 */
196 void squash(InstSeqNum squash_num, unsigned tid);
197
198 /** Updates the head instruction with the new oldest instruction. */
199 void updateHead();
200
201 /** Updates the tail instruction with the new youngest instruction. */
202 void updateTail();
203
204 /** Reads the PC of the oldest head instruction. */
205// uint64_t readHeadPC();
206
207 /** Reads the PC of the head instruction of a specific thread. */
208// uint64_t readHeadPC(unsigned tid);
209
210 /** Reads the next PC of the oldest head instruction. */
211// uint64_t readHeadNextPC();
212
213 /** Reads the next PC of the head instruction of a specific thread. */
214// uint64_t readHeadNextPC(unsigned tid);
215
216 /** Reads the sequence number of the oldest head instruction. */
217// InstSeqNum readHeadSeqNum();
218
219 /** Reads the sequence number of the head instruction of a specific thread.
220 */
221// InstSeqNum readHeadSeqNum(unsigned tid);
222
223 /** Reads the PC of the youngest tail instruction. */
224// uint64_t readTailPC();
225
226 /** Reads the PC of the tail instruction of a specific thread. */
227// uint64_t readTailPC(unsigned tid);
228
229 /** Reads the sequence number of the youngest tail instruction. */
230// InstSeqNum readTailSeqNum();
231
232 /** Reads the sequence number of tail instruction of a specific thread. */
233// InstSeqNum readTailSeqNum(unsigned tid);
234
235 /** Checks if the ROB is still in the process of squashing instructions.
236 * @retval Whether or not the ROB is done squashing.
237 */
238 bool isDoneSquashing(unsigned tid) const
239 { return doneSquashing[tid]; }
240
241 /** Checks if the ROB is still in the process of squashing instructions for
242 * any thread.
243 */
244 bool isDoneSquashing();
245
246 /** This is more of a debugging function than anything. Use
247 * numInstsInROB to get the instructions in the ROB unless you are
248 * double checking that variable.
249 */
250 int countInsts();
251
252 /** This is more of a debugging function than anything. Use
253 * threadEntries to get the instructions in the ROB unless you are
254 * double checking that variable.
255 */
256 int countInsts(unsigned tid);
257
258 private:
259 /** Pointer to the CPU. */
260 FullCPU *cpu;
261
262 /** Active Threads in CPU */
263 std::list<unsigned>* activeThreads;
264
265 /** Number of instructions in the ROB. */
266 unsigned numEntries;
267
268 /** Entries Per Thread */
269 unsigned threadEntries[Impl::MaxThreads];
270
271 /** Max Insts a Thread Can Have in the ROB */
272 unsigned maxEntries[Impl::MaxThreads];
273
274 /** ROB List of Instructions */
275 std::list<DynInstPtr> instList[Impl::MaxThreads];
276
277 /** Number of instructions that can be squashed in a single cycle. */
278 unsigned squashWidth;
279
280 public:
281 /** Iterator pointing to the instruction which is the last instruction
282 * in the ROB. This may at times be invalid (ie when the ROB is empty),
283 * however it should never be incorrect.
284 */
285 InstIt tail;
286
287 /** Iterator pointing to the instruction which is the first instruction in
288 * in the ROB*/
289 InstIt head;
290
291 private:
292 /** Iterator used for walking through the list of instructions when
293 * squashing. Used so that there is persistent state between cycles;
294 * when squashing, the instructions are marked as squashed but not
295 * immediately removed, meaning the tail iterator remains the same before
296 * and after a squash.
297 * This will always be set to cpu->instList.end() if it is invalid.
298 */
299 InstIt squashIt[Impl::MaxThreads];
300
301 public:
302 /** Number of instructions in the ROB. */
303 int numInstsInROB;
304
|