| 1/*
2 * Copyright (c) 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 */
|
1
2#ifndef __CPU_O3_DEP_GRAPH_HH__
3#define __CPU_O3_DEP_GRAPH_HH__
4
5#include "cpu/o3/comm.hh"
6
7/** Node in a linked list. */
8template <class DynInstPtr>
9class DependencyEntry
10{
11 public:
12 DependencyEntry()
13 : inst(NULL), next(NULL)
14 { }
15
16 DynInstPtr inst;
17 //Might want to include data about what arch. register the
18 //dependence is waiting on.
19 DependencyEntry<DynInstPtr> *next;
20};
21
22/** Array of linked list that maintains the dependencies between
23 * producing instructions and consuming instructions. Each linked
24 * list represents a single physical register, having the future
25 * producer of the register's value, and all consumers waiting on that
26 * value on the list. The head node of each linked list represents
27 * the producing instruction of that register. Instructions are put
28 * on the list upon reaching the IQ, and are removed from the list
29 * either when the producer completes, or the instruction is squashed.
30*/
31template <class DynInstPtr>
32class DependencyGraph
33{
34 public:
35 typedef DependencyEntry<DynInstPtr> DepEntry;
36
37 /** Default construction. Must call resize() prior to use. */
38 DependencyGraph()
39 : numEntries(0), memAllocCounter(0), nodesTraversed(0), nodesRemoved(0)
40 { }
41
42 /** Resize the dependency graph to have num_entries registers. */
43 void resize(int num_entries);
44
45 /** Clears all of the linked lists. */
46 void reset();
47
48 /** Inserts an instruction to be dependent on the given index. */
49 void insert(PhysRegIndex idx, DynInstPtr &new_inst);
50
51 /** Sets the producing instruction of a given register. */
52 void setInst(PhysRegIndex idx, DynInstPtr &new_inst)
53 { dependGraph[idx].inst = new_inst; }
54
55 /** Clears the producing instruction. */
56 void clearInst(PhysRegIndex idx)
57 { dependGraph[idx].inst = NULL; }
58
59 /** Removes an instruction from a single linked list. */
60 void remove(PhysRegIndex idx, DynInstPtr &inst_to_remove);
61
62 /** Removes and returns the newest dependent of a specific register. */
63 DynInstPtr pop(PhysRegIndex idx);
64
65 /** Checks if there are any dependents on a specific register. */
66 bool empty(PhysRegIndex idx) { return !dependGraph[idx].next; }
67
68 /** Debugging function to dump out the dependency graph.
69 */
70 void dump();
71
72 private:
73 /** Array of linked lists. Each linked list is a list of all the
74 * instructions that depend upon a given register. The actual
75 * register's index is used to index into the graph; ie all
76 * instructions in flight that are dependent upon r34 will be
77 * in the linked list of dependGraph[34].
78 */
79 DepEntry *dependGraph;
80
81 /** Number of linked lists; identical to the number of registers. */
82 int numEntries;
83
84 // Debug variable, remove when done testing.
85 unsigned memAllocCounter;
86
87 public:
88 // Debug variable, remove when done testing.
89 uint64_t nodesTraversed;
90 // Debug variable, remove when done testing.
91 uint64_t nodesRemoved;
92};
93
94template <class DynInstPtr>
95void
96DependencyGraph<DynInstPtr>::resize(int num_entries)
97{
98 numEntries = num_entries;
99 dependGraph = new DepEntry[numEntries];
100}
101
102template <class DynInstPtr>
103void
104DependencyGraph<DynInstPtr>::reset()
105{
106 // Clear the dependency graph
107 DepEntry *curr;
108 DepEntry *prev;
109
110 for (int i = 0; i < numEntries; ++i) {
111 curr = dependGraph[i].next;
112
113 while (curr) {
114 memAllocCounter--;
115
116 prev = curr;
117 curr = prev->next;
118 prev->inst = NULL;
119
120 delete prev;
121 }
122
123 if (dependGraph[i].inst) {
124 dependGraph[i].inst = NULL;
125 }
126
127 dependGraph[i].next = NULL;
128 }
129}
130
131template <class DynInstPtr>
132void
133DependencyGraph<DynInstPtr>::insert(PhysRegIndex idx, DynInstPtr &new_inst)
134{
135 //Add this new, dependent instruction at the head of the dependency
136 //chain.
137
138 // First create the entry that will be added to the head of the
139 // dependency chain.
140 DepEntry *new_entry = new DepEntry;
141 new_entry->next = dependGraph[idx].next;
142 new_entry->inst = new_inst;
143
144 // Then actually add it to the chain.
145 dependGraph[idx].next = new_entry;
146
147 ++memAllocCounter;
148}
149
150
151template <class DynInstPtr>
152void
153DependencyGraph<DynInstPtr>::remove(PhysRegIndex idx,
154 DynInstPtr &inst_to_remove)
155{
156 DepEntry *prev = &dependGraph[idx];
157 DepEntry *curr = dependGraph[idx].next;
158
159 // Make sure curr isn't NULL. Because this instruction is being
160 // removed from a dependency list, it must have been placed there at
161 // an earlier time. The dependency chain should not be empty,
162 // unless the instruction dependent upon it is already ready.
163 if (curr == NULL) {
164 return;
165 }
166
167 nodesRemoved++;
168
169 // Find the instruction to remove within the dependency linked list.
170 while (curr->inst != inst_to_remove) {
171 prev = curr;
172 curr = curr->next;
173 nodesTraversed++;
174
175 assert(curr != NULL);
176 }
177
178 // Now remove this instruction from the list.
179 prev->next = curr->next;
180
181 --memAllocCounter;
182
183 // Could push this off to the destructor of DependencyEntry
184 curr->inst = NULL;
185
186 delete curr;
187}
188
189template <class DynInstPtr>
190DynInstPtr
191DependencyGraph<DynInstPtr>::pop(PhysRegIndex idx)
192{
193 DepEntry *node;
194 node = dependGraph[idx].next;
195 DynInstPtr inst = NULL;
196 if (node) {
197 inst = node->inst;
198 dependGraph[idx].next = node->next;
199 node->inst = NULL;
200 memAllocCounter--;
201 delete node;
202 }
203 return inst;
204}
205
206template <class DynInstPtr>
207void
208DependencyGraph<DynInstPtr>::dump()
209{
210 DepEntry *curr;
211
212 for (int i = 0; i < numEntries; ++i)
213 {
214 curr = &dependGraph[i];
215
216 if (curr->inst) {
217 cprintf("dependGraph[%i]: producer: %#x [sn:%lli] consumer: ",
218 i, curr->inst->readPC(), curr->inst->seqNum);
219 } else {
220 cprintf("dependGraph[%i]: No producer. consumer: ", i);
221 }
222
223 while (curr->next != NULL) {
224 curr = curr->next;
225
226 cprintf("%#x [sn:%lli] ",
227 curr->inst->readPC(), curr->inst->seqNum);
228 }
229
230 cprintf("\n");
231 }
232 cprintf("memAllocCounter: %i\n", memAllocCounter);
233}
234
235#endif // __CPU_O3_DEP_GRAPH_HH__
| 30
31#ifndef __CPU_O3_DEP_GRAPH_HH__
32#define __CPU_O3_DEP_GRAPH_HH__
33
34#include "cpu/o3/comm.hh"
35
36/** Node in a linked list. */
37template <class DynInstPtr>
38class DependencyEntry
39{
40 public:
41 DependencyEntry()
42 : inst(NULL), next(NULL)
43 { }
44
45 DynInstPtr inst;
46 //Might want to include data about what arch. register the
47 //dependence is waiting on.
48 DependencyEntry<DynInstPtr> *next;
49};
50
51/** Array of linked list that maintains the dependencies between
52 * producing instructions and consuming instructions. Each linked
53 * list represents a single physical register, having the future
54 * producer of the register's value, and all consumers waiting on that
55 * value on the list. The head node of each linked list represents
56 * the producing instruction of that register. Instructions are put
57 * on the list upon reaching the IQ, and are removed from the list
58 * either when the producer completes, or the instruction is squashed.
59*/
60template <class DynInstPtr>
61class DependencyGraph
62{
63 public:
64 typedef DependencyEntry<DynInstPtr> DepEntry;
65
66 /** Default construction. Must call resize() prior to use. */
67 DependencyGraph()
68 : numEntries(0), memAllocCounter(0), nodesTraversed(0), nodesRemoved(0)
69 { }
70
71 /** Resize the dependency graph to have num_entries registers. */
72 void resize(int num_entries);
73
74 /** Clears all of the linked lists. */
75 void reset();
76
77 /** Inserts an instruction to be dependent on the given index. */
78 void insert(PhysRegIndex idx, DynInstPtr &new_inst);
79
80 /** Sets the producing instruction of a given register. */
81 void setInst(PhysRegIndex idx, DynInstPtr &new_inst)
82 { dependGraph[idx].inst = new_inst; }
83
84 /** Clears the producing instruction. */
85 void clearInst(PhysRegIndex idx)
86 { dependGraph[idx].inst = NULL; }
87
88 /** Removes an instruction from a single linked list. */
89 void remove(PhysRegIndex idx, DynInstPtr &inst_to_remove);
90
91 /** Removes and returns the newest dependent of a specific register. */
92 DynInstPtr pop(PhysRegIndex idx);
93
94 /** Checks if there are any dependents on a specific register. */
95 bool empty(PhysRegIndex idx) { return !dependGraph[idx].next; }
96
97 /** Debugging function to dump out the dependency graph.
98 */
99 void dump();
100
101 private:
102 /** Array of linked lists. Each linked list is a list of all the
103 * instructions that depend upon a given register. The actual
104 * register's index is used to index into the graph; ie all
105 * instructions in flight that are dependent upon r34 will be
106 * in the linked list of dependGraph[34].
107 */
108 DepEntry *dependGraph;
109
110 /** Number of linked lists; identical to the number of registers. */
111 int numEntries;
112
113 // Debug variable, remove when done testing.
114 unsigned memAllocCounter;
115
116 public:
117 // Debug variable, remove when done testing.
118 uint64_t nodesTraversed;
119 // Debug variable, remove when done testing.
120 uint64_t nodesRemoved;
121};
122
123template <class DynInstPtr>
124void
125DependencyGraph<DynInstPtr>::resize(int num_entries)
126{
127 numEntries = num_entries;
128 dependGraph = new DepEntry[numEntries];
129}
130
131template <class DynInstPtr>
132void
133DependencyGraph<DynInstPtr>::reset()
134{
135 // Clear the dependency graph
136 DepEntry *curr;
137 DepEntry *prev;
138
139 for (int i = 0; i < numEntries; ++i) {
140 curr = dependGraph[i].next;
141
142 while (curr) {
143 memAllocCounter--;
144
145 prev = curr;
146 curr = prev->next;
147 prev->inst = NULL;
148
149 delete prev;
150 }
151
152 if (dependGraph[i].inst) {
153 dependGraph[i].inst = NULL;
154 }
155
156 dependGraph[i].next = NULL;
157 }
158}
159
160template <class DynInstPtr>
161void
162DependencyGraph<DynInstPtr>::insert(PhysRegIndex idx, DynInstPtr &new_inst)
163{
164 //Add this new, dependent instruction at the head of the dependency
165 //chain.
166
167 // First create the entry that will be added to the head of the
168 // dependency chain.
169 DepEntry *new_entry = new DepEntry;
170 new_entry->next = dependGraph[idx].next;
171 new_entry->inst = new_inst;
172
173 // Then actually add it to the chain.
174 dependGraph[idx].next = new_entry;
175
176 ++memAllocCounter;
177}
178
179
180template <class DynInstPtr>
181void
182DependencyGraph<DynInstPtr>::remove(PhysRegIndex idx,
183 DynInstPtr &inst_to_remove)
184{
185 DepEntry *prev = &dependGraph[idx];
186 DepEntry *curr = dependGraph[idx].next;
187
188 // Make sure curr isn't NULL. Because this instruction is being
189 // removed from a dependency list, it must have been placed there at
190 // an earlier time. The dependency chain should not be empty,
191 // unless the instruction dependent upon it is already ready.
192 if (curr == NULL) {
193 return;
194 }
195
196 nodesRemoved++;
197
198 // Find the instruction to remove within the dependency linked list.
199 while (curr->inst != inst_to_remove) {
200 prev = curr;
201 curr = curr->next;
202 nodesTraversed++;
203
204 assert(curr != NULL);
205 }
206
207 // Now remove this instruction from the list.
208 prev->next = curr->next;
209
210 --memAllocCounter;
211
212 // Could push this off to the destructor of DependencyEntry
213 curr->inst = NULL;
214
215 delete curr;
216}
217
218template <class DynInstPtr>
219DynInstPtr
220DependencyGraph<DynInstPtr>::pop(PhysRegIndex idx)
221{
222 DepEntry *node;
223 node = dependGraph[idx].next;
224 DynInstPtr inst = NULL;
225 if (node) {
226 inst = node->inst;
227 dependGraph[idx].next = node->next;
228 node->inst = NULL;
229 memAllocCounter--;
230 delete node;
231 }
232 return inst;
233}
234
235template <class DynInstPtr>
236void
237DependencyGraph<DynInstPtr>::dump()
238{
239 DepEntry *curr;
240
241 for (int i = 0; i < numEntries; ++i)
242 {
243 curr = &dependGraph[i];
244
245 if (curr->inst) {
246 cprintf("dependGraph[%i]: producer: %#x [sn:%lli] consumer: ",
247 i, curr->inst->readPC(), curr->inst->seqNum);
248 } else {
249 cprintf("dependGraph[%i]: No producer. consumer: ", i);
250 }
251
252 while (curr->next != NULL) {
253 curr = curr->next;
254
255 cprintf("%#x [sn:%lli] ",
256 curr->inst->readPC(), curr->inst->seqNum);
257 }
258
259 cprintf("\n");
260 }
261 cprintf("memAllocCounter: %i\n", memAllocCounter);
262}
263
264#endif // __CPU_O3_DEP_GRAPH_HH__
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