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 * Korey Sewell
30 */
31
32#ifndef __CPU_O3_ROB_HH__
33#define __CPU_O3_ROB_HH__
34
35#include <string>
36#include <utility>
37#include <vector>
38
39/**
40 * ROB class. The ROB is largely what drives squashing.
41 */
42template <class Impl>
43class ROB
44{
45 protected:
46 typedef TheISA::RegIndex RegIndex;
47 public:
48 //Typedefs from the Impl.
49 typedef typename Impl::O3CPU O3CPU;
50 typedef typename Impl::DynInstPtr DynInstPtr;
51
52 typedef std::pair<RegIndex, PhysRegIndex> UnmapInfo;
53 typedef typename std::list<DynInstPtr>::iterator InstIt;
54
55 /** Possible ROB statuses. */
56 enum Status {
57 Running,
58 Idle,
59 ROBSquashing
60 };
61
62 /** SMT ROB Sharing Policy */
63 enum ROBPolicy{
64 Dynamic,
65 Partitioned,
66 Threshold
67 };
68
69 private:
70 /** Per-thread ROB status. */
71 Status robStatus[Impl::MaxThreads];
72
73 /** ROB resource sharing policy for SMT mode. */
74 ROBPolicy robPolicy;
75
76 public:
77 /** ROB constructor.
78 * @param _numEntries Number of entries in ROB.
79 * @param _squashWidth Number of instructions that can be squashed in a
80 * single cycle.
81 * @param _smtROBPolicy ROB Partitioning Scheme for SMT.
82 * @param _smtROBThreshold Max Resources(by %) a thread can have in the ROB.
83 * @param _numThreads The number of active threads.
84 */
85 ROB(unsigned _numEntries, unsigned _squashWidth, std::string smtROBPolicy,
86 unsigned _smtROBThreshold, unsigned _numThreads);
87
88 std::string name() const;
89
90 /** Function to set the CPU pointer, necessary due to which object the ROB
91 * is created within.
92 * @param cpu_ptr Pointer to the implementation specific full CPU object.
93 */
94 void setCPU(O3CPU *cpu_ptr);
95
96 /** Sets pointer to the list of active threads.
97 * @param at_ptr Pointer to the list of active threads.
98 */
99 void setActiveThreads(std::list<unsigned>* at_ptr);
100
101 /** Switches out the ROB. */
102 void switchOut();
103
104 /** Takes over another CPU's thread. */
105 void takeOverFrom();
106
107 /** Function to insert an instruction into the ROB. Note that whatever
108 * calls this function must ensure that there is enough space within the
109 * ROB for the new instruction.
110 * @param inst The instruction being inserted into the ROB.
111 */
112 void insertInst(DynInstPtr &inst);
113
114 /** Returns pointer to the head instruction within the ROB. There is
115 * no guarantee as to the return value if the ROB is empty.
116 * @retval Pointer to the DynInst that is at the head of the ROB.
117 */
118// DynInstPtr readHeadInst();
119
120 /** Returns a pointer to the head instruction of a specific thread within
121 * the ROB.
122 * @return Pointer to the DynInst that is at the head of the ROB.
123 */
124 DynInstPtr readHeadInst(unsigned tid);
125
126 /** Returns pointer to the tail instruction within the ROB. There is
127 * no guarantee as to the return value if the ROB is empty.
128 * @retval Pointer to the DynInst that is at the tail of the ROB.
129 */
130// DynInstPtr readTailInst();
131
132 /** Returns a pointer to the tail instruction of a specific thread within
133 * the ROB.
134 * @return Pointer to the DynInst that is at the tail of the ROB.
135 */
136 DynInstPtr readTailInst(unsigned tid);
137
138 /** Retires the head instruction, removing it from the ROB. */
139// void retireHead();
140
141 /** Retires the head instruction of a specific thread, removing it from the
142 * ROB.
143 */
144 void retireHead(unsigned tid);
145
146 /** Is the oldest instruction across all threads ready. */
147// bool isHeadReady();
148
149 /** Is the oldest instruction across a particular thread ready. */
150 bool isHeadReady(unsigned tid);
151
152 /** Is there any commitable head instruction across all threads ready. */
153 bool canCommit();
154
155 /** Re-adjust ROB partitioning. */
156 void resetEntries();
157
158 /** Number of entries needed For 'num_threads' amount of threads. */
159 int entryAmount(int num_threads);
160
161 /** Returns the number of total free entries in the ROB. */
162 unsigned numFreeEntries();
163
164 /** Returns the number of free entries in a specific ROB paritition. */
165 unsigned numFreeEntries(unsigned tid);
166
167 /** Returns the maximum number of entries for a specific thread. */
168 unsigned getMaxEntries(unsigned tid)
169 { return maxEntries[tid]; }
170
171 /** Returns the number of entries being used by a specific thread. */
172 unsigned getThreadEntries(unsigned tid)
173 { return threadEntries[tid]; }
174
175 /** Returns if the ROB is full. */
176 bool isFull()
177 { return numInstsInROB == numEntries; }
178
179 /** Returns if a specific thread's partition is full. */
180 bool isFull(unsigned tid)
181 { return threadEntries[tid] == numEntries; }
182
183 /** Returns if the ROB is empty. */
184 bool isEmpty()
185 { return numInstsInROB == 0; }
186
187 /** Returns if a specific thread's partition is empty. */
188 bool isEmpty(unsigned tid)
189 { return threadEntries[tid] == 0; }
190
191 /** Executes the squash, marking squashed instructions. */
192 void doSquash(unsigned tid);
193
194 /** Squashes all instructions younger than the given sequence number for
195 * the specific thread.
196 */
197 void squash(InstSeqNum squash_num, unsigned tid);
198
199 /** Updates the head instruction with the new oldest instruction. */
200 void updateHead();
201
202 /** Updates the tail instruction with the new youngest instruction. */
203 void updateTail();
204
205 /** Reads the PC of the oldest head instruction. */
206// uint64_t readHeadPC();
207
208 /** Reads the PC of the head instruction of a specific thread. */
209// uint64_t readHeadPC(unsigned tid);
210
211 /** Reads the next PC of the oldest head instruction. */
212// uint64_t readHeadNextPC();
213
214 /** Reads the next PC of the head instruction of a specific thread. */
215// uint64_t readHeadNextPC(unsigned tid);
216
217 /** Reads the sequence number of the oldest head instruction. */
218// InstSeqNum readHeadSeqNum();
219
220 /** Reads the sequence number of the head instruction of a specific thread.
221 */
222// InstSeqNum readHeadSeqNum(unsigned tid);
223
224 /** Reads the PC of the youngest tail instruction. */
225// uint64_t readTailPC();
226
227 /** Reads the PC of the tail instruction of a specific thread. */
228// uint64_t readTailPC(unsigned tid);
229
230 /** Reads the sequence number of the youngest tail instruction. */
231// InstSeqNum readTailSeqNum();
232
233 /** Reads the sequence number of tail instruction of a specific thread. */
234// InstSeqNum readTailSeqNum(unsigned tid);
235
236 /** Checks if the ROB is still in the process of squashing instructions.
237 * @retval Whether or not the ROB is done squashing.
238 */
239 bool isDoneSquashing(unsigned tid) const
240 { return doneSquashing[tid]; }
241
242 /** Checks if the ROB is still in the process of squashing instructions for
243 * any thread.
244 */
245 bool isDoneSquashing();
246
247 /** This is more of a debugging function than anything. Use
248 * numInstsInROB to get the instructions in the ROB unless you are
249 * double checking that variable.
250 */
251 int countInsts();
252
253 /** This is more of a debugging function than anything. Use
254 * threadEntries to get the instructions in the ROB unless you are
255 * double checking that variable.
256 */
257 int countInsts(unsigned tid);
258
259 private:
260 /** Pointer to the CPU. */
261 O3CPU *cpu;
262
263 /** Active Threads in CPU */
264 std::list<unsigned>* activeThreads;
265
266 /** Number of instructions in the ROB. */
267 unsigned numEntries;
268
269 /** Entries Per Thread */
270 unsigned threadEntries[Impl::MaxThreads];
271
272 /** Max Insts a Thread Can Have in the ROB */
273 unsigned maxEntries[Impl::MaxThreads];
274
275 /** ROB List of Instructions */
276 std::list<DynInstPtr> instList[Impl::MaxThreads];
277
278 /** Number of instructions that can be squashed in a single cycle. */
279 unsigned squashWidth;
280
281 public:
282 /** Iterator pointing to the instruction which is the last instruction
283 * in the ROB. This may at times be invalid (ie when the ROB is empty),
284 * however it should never be incorrect.
285 */
286 InstIt tail;
287
288 /** Iterator pointing to the instruction which is the first instruction in
289 * in the ROB*/
290 InstIt head;
291
292 private:
293 /** Iterator used for walking through the list of instructions when
294 * squashing. Used so that there is persistent state between cycles;
295 * when squashing, the instructions are marked as squashed but not
296 * immediately removed, meaning the tail iterator remains the same before
297 * and after a squash.
298 * This will always be set to cpu->instList.end() if it is invalid.
299 */
300 InstIt squashIt[Impl::MaxThreads];
301
302 public:
303 /** Number of instructions in the ROB. */
304 int numInstsInROB;
305
306 /** Dummy instruction returned if there are no insts left. */
307 DynInstPtr dummyInst;
308
309 private:
310 /** The sequence number of the squashed instruction. */
| 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 * Korey Sewell
30 */
31
32#ifndef __CPU_O3_ROB_HH__
33#define __CPU_O3_ROB_HH__
34
35#include <string>
36#include <utility>
37#include <vector>
38
39/**
40 * ROB class. The ROB is largely what drives squashing.
41 */
42template <class Impl>
43class ROB
44{
45 protected:
46 typedef TheISA::RegIndex RegIndex;
47 public:
48 //Typedefs from the Impl.
49 typedef typename Impl::O3CPU O3CPU;
50 typedef typename Impl::DynInstPtr DynInstPtr;
51
52 typedef std::pair<RegIndex, PhysRegIndex> UnmapInfo;
53 typedef typename std::list<DynInstPtr>::iterator InstIt;
54
55 /** Possible ROB statuses. */
56 enum Status {
57 Running,
58 Idle,
59 ROBSquashing
60 };
61
62 /** SMT ROB Sharing Policy */
63 enum ROBPolicy{
64 Dynamic,
65 Partitioned,
66 Threshold
67 };
68
69 private:
70 /** Per-thread ROB status. */
71 Status robStatus[Impl::MaxThreads];
72
73 /** ROB resource sharing policy for SMT mode. */
74 ROBPolicy robPolicy;
75
76 public:
77 /** ROB constructor.
78 * @param _numEntries Number of entries in ROB.
79 * @param _squashWidth Number of instructions that can be squashed in a
80 * single cycle.
81 * @param _smtROBPolicy ROB Partitioning Scheme for SMT.
82 * @param _smtROBThreshold Max Resources(by %) a thread can have in the ROB.
83 * @param _numThreads The number of active threads.
84 */
85 ROB(unsigned _numEntries, unsigned _squashWidth, std::string smtROBPolicy,
86 unsigned _smtROBThreshold, unsigned _numThreads);
87
88 std::string name() const;
89
90 /** Function to set the CPU pointer, necessary due to which object the ROB
91 * is created within.
92 * @param cpu_ptr Pointer to the implementation specific full CPU object.
93 */
94 void setCPU(O3CPU *cpu_ptr);
95
96 /** Sets pointer to the list of active threads.
97 * @param at_ptr Pointer to the list of active threads.
98 */
99 void setActiveThreads(std::list<unsigned>* at_ptr);
100
101 /** Switches out the ROB. */
102 void switchOut();
103
104 /** Takes over another CPU's thread. */
105 void takeOverFrom();
106
107 /** Function to insert an instruction into the ROB. Note that whatever
108 * calls this function must ensure that there is enough space within the
109 * ROB for the new instruction.
110 * @param inst The instruction being inserted into the ROB.
111 */
112 void insertInst(DynInstPtr &inst);
113
114 /** Returns pointer to the head instruction within the ROB. There is
115 * no guarantee as to the return value if the ROB is empty.
116 * @retval Pointer to the DynInst that is at the head of the ROB.
117 */
118// DynInstPtr readHeadInst();
119
120 /** Returns a pointer to the head instruction of a specific thread within
121 * the ROB.
122 * @return Pointer to the DynInst that is at the head of the ROB.
123 */
124 DynInstPtr readHeadInst(unsigned tid);
125
126 /** Returns pointer to the tail instruction within the ROB. There is
127 * no guarantee as to the return value if the ROB is empty.
128 * @retval Pointer to the DynInst that is at the tail of the ROB.
129 */
130// DynInstPtr readTailInst();
131
132 /** Returns a pointer to the tail instruction of a specific thread within
133 * the ROB.
134 * @return Pointer to the DynInst that is at the tail of the ROB.
135 */
136 DynInstPtr readTailInst(unsigned tid);
137
138 /** Retires the head instruction, removing it from the ROB. */
139// void retireHead();
140
141 /** Retires the head instruction of a specific thread, removing it from the
142 * ROB.
143 */
144 void retireHead(unsigned tid);
145
146 /** Is the oldest instruction across all threads ready. */
147// bool isHeadReady();
148
149 /** Is the oldest instruction across a particular thread ready. */
150 bool isHeadReady(unsigned tid);
151
152 /** Is there any commitable head instruction across all threads ready. */
153 bool canCommit();
154
155 /** Re-adjust ROB partitioning. */
156 void resetEntries();
157
158 /** Number of entries needed For 'num_threads' amount of threads. */
159 int entryAmount(int num_threads);
160
161 /** Returns the number of total free entries in the ROB. */
162 unsigned numFreeEntries();
163
164 /** Returns the number of free entries in a specific ROB paritition. */
165 unsigned numFreeEntries(unsigned tid);
166
167 /** Returns the maximum number of entries for a specific thread. */
168 unsigned getMaxEntries(unsigned tid)
169 { return maxEntries[tid]; }
170
171 /** Returns the number of entries being used by a specific thread. */
172 unsigned getThreadEntries(unsigned tid)
173 { return threadEntries[tid]; }
174
175 /** Returns if the ROB is full. */
176 bool isFull()
177 { return numInstsInROB == numEntries; }
178
179 /** Returns if a specific thread's partition is full. */
180 bool isFull(unsigned tid)
181 { return threadEntries[tid] == numEntries; }
182
183 /** Returns if the ROB is empty. */
184 bool isEmpty()
185 { return numInstsInROB == 0; }
186
187 /** Returns if a specific thread's partition is empty. */
188 bool isEmpty(unsigned tid)
189 { return threadEntries[tid] == 0; }
190
191 /** Executes the squash, marking squashed instructions. */
192 void doSquash(unsigned tid);
193
194 /** Squashes all instructions younger than the given sequence number for
195 * the specific thread.
196 */
197 void squash(InstSeqNum squash_num, unsigned tid);
198
199 /** Updates the head instruction with the new oldest instruction. */
200 void updateHead();
201
202 /** Updates the tail instruction with the new youngest instruction. */
203 void updateTail();
204
205 /** Reads the PC of the oldest head instruction. */
206// uint64_t readHeadPC();
207
208 /** Reads the PC of the head instruction of a specific thread. */
209// uint64_t readHeadPC(unsigned tid);
210
211 /** Reads the next PC of the oldest head instruction. */
212// uint64_t readHeadNextPC();
213
214 /** Reads the next PC of the head instruction of a specific thread. */
215// uint64_t readHeadNextPC(unsigned tid);
216
217 /** Reads the sequence number of the oldest head instruction. */
218// InstSeqNum readHeadSeqNum();
219
220 /** Reads the sequence number of the head instruction of a specific thread.
221 */
222// InstSeqNum readHeadSeqNum(unsigned tid);
223
224 /** Reads the PC of the youngest tail instruction. */
225// uint64_t readTailPC();
226
227 /** Reads the PC of the tail instruction of a specific thread. */
228// uint64_t readTailPC(unsigned tid);
229
230 /** Reads the sequence number of the youngest tail instruction. */
231// InstSeqNum readTailSeqNum();
232
233 /** Reads the sequence number of tail instruction of a specific thread. */
234// InstSeqNum readTailSeqNum(unsigned tid);
235
236 /** Checks if the ROB is still in the process of squashing instructions.
237 * @retval Whether or not the ROB is done squashing.
238 */
239 bool isDoneSquashing(unsigned tid) const
240 { return doneSquashing[tid]; }
241
242 /** Checks if the ROB is still in the process of squashing instructions for
243 * any thread.
244 */
245 bool isDoneSquashing();
246
247 /** This is more of a debugging function than anything. Use
248 * numInstsInROB to get the instructions in the ROB unless you are
249 * double checking that variable.
250 */
251 int countInsts();
252
253 /** This is more of a debugging function than anything. Use
254 * threadEntries to get the instructions in the ROB unless you are
255 * double checking that variable.
256 */
257 int countInsts(unsigned tid);
258
259 private:
260 /** Pointer to the CPU. */
261 O3CPU *cpu;
262
263 /** Active Threads in CPU */
264 std::list<unsigned>* activeThreads;
265
266 /** Number of instructions in the ROB. */
267 unsigned numEntries;
268
269 /** Entries Per Thread */
270 unsigned threadEntries[Impl::MaxThreads];
271
272 /** Max Insts a Thread Can Have in the ROB */
273 unsigned maxEntries[Impl::MaxThreads];
274
275 /** ROB List of Instructions */
276 std::list<DynInstPtr> instList[Impl::MaxThreads];
277
278 /** Number of instructions that can be squashed in a single cycle. */
279 unsigned squashWidth;
280
281 public:
282 /** Iterator pointing to the instruction which is the last instruction
283 * in the ROB. This may at times be invalid (ie when the ROB is empty),
284 * however it should never be incorrect.
285 */
286 InstIt tail;
287
288 /** Iterator pointing to the instruction which is the first instruction in
289 * in the ROB*/
290 InstIt head;
291
292 private:
293 /** Iterator used for walking through the list of instructions when
294 * squashing. Used so that there is persistent state between cycles;
295 * when squashing, the instructions are marked as squashed but not
296 * immediately removed, meaning the tail iterator remains the same before
297 * and after a squash.
298 * This will always be set to cpu->instList.end() if it is invalid.
299 */
300 InstIt squashIt[Impl::MaxThreads];
301
302 public:
303 /** Number of instructions in the ROB. */
304 int numInstsInROB;
305
306 /** Dummy instruction returned if there are no insts left. */
307 DynInstPtr dummyInst;
308
309 private:
310 /** The sequence number of the squashed instruction. */
|