dep_graph.hh revision 2326
1 2#ifndef __CPU_O3_DEP_GRAPH_HH__ 3#define __CPU_O3_DEP_GRAPH_HH__ 4 5#include "cpu/o3/comm.hh" 6 7template <class DynInstPtr> 8class DependencyEntry 9{ 10 public: 11 DependencyEntry() 12 : inst(NULL), next(NULL) 13 { } 14 15 DynInstPtr inst; 16 //Might want to include data about what arch. register the 17 //dependence is waiting on. 18 DependencyEntry<DynInstPtr> *next; 19}; 20 21template <class DynInstPtr> 22class DependencyGraph 23{ 24 public: 25 typedef DependencyEntry<DynInstPtr> DepEntry; 26 27 DependencyGraph() 28 : numEntries(0), memAllocCounter(0), nodesTraversed(0), nodesRemoved(0) 29 { } 30 31 void resize(int num_entries); 32 33 void reset(); 34 35 void insert(PhysRegIndex idx, DynInstPtr &new_inst); 36 37 void setInst(PhysRegIndex idx, DynInstPtr &new_inst) 38 { dependGraph[idx].inst = new_inst; } 39 40 void clearInst(PhysRegIndex idx) 41 { dependGraph[idx].inst = NULL; } 42 43 void remove(PhysRegIndex idx, DynInstPtr &inst_to_remove); 44 45 DynInstPtr pop(PhysRegIndex idx); 46 47 bool empty(PhysRegIndex idx) { return !dependGraph[idx].next; } 48 49 /** Debugging function to dump out the dependency graph. 50 */ 51 void dump(); 52 53 private: 54 /** Array of linked lists. Each linked list is a list of all the 55 * instructions that depend upon a given register. The actual 56 * register's index is used to index into the graph; ie all 57 * instructions in flight that are dependent upon r34 will be 58 * in the linked list of dependGraph[34]. 59 */ 60 DepEntry *dependGraph; 61 62 int numEntries; 63 64 // Debug variable, remove when done testing. 65 unsigned memAllocCounter; 66 67 public: 68 uint64_t nodesTraversed; 69 uint64_t nodesRemoved; 70}; 71 72template <class DynInstPtr> 73void 74DependencyGraph<DynInstPtr>::resize(int num_entries) 75{ 76 numEntries = num_entries; 77 dependGraph = new DepEntry[numEntries]; 78} 79 80template <class DynInstPtr> 81void 82DependencyGraph<DynInstPtr>::reset() 83{ 84 // Clear the dependency graph 85 DepEntry *curr; 86 DepEntry *prev; 87 88 for (int i = 0; i < numEntries; ++i) { 89 curr = dependGraph[i].next; 90 91 while (curr) { 92 memAllocCounter--; 93 94 prev = curr; 95 curr = prev->next; 96 prev->inst = NULL; 97 98 delete prev; 99 } 100 101 if (dependGraph[i].inst) { 102 dependGraph[i].inst = NULL; 103 } 104 105 dependGraph[i].next = NULL; 106 } 107} 108 109template <class DynInstPtr> 110void 111DependencyGraph<DynInstPtr>::insert(PhysRegIndex idx, DynInstPtr &new_inst) 112{ 113 //Add this new, dependent instruction at the head of the dependency 114 //chain. 115 116 // First create the entry that will be added to the head of the 117 // dependency chain. 118 DepEntry *new_entry = new DepEntry; 119 new_entry->next = dependGraph[idx].next; 120 new_entry->inst = new_inst; 121 122 // Then actually add it to the chain. 123 dependGraph[idx].next = new_entry; 124 125 ++memAllocCounter; 126} 127 128 129template <class DynInstPtr> 130void 131DependencyGraph<DynInstPtr>::remove(PhysRegIndex idx, 132 DynInstPtr &inst_to_remove) 133{ 134 DepEntry *prev = &dependGraph[idx]; 135 DepEntry *curr = dependGraph[idx].next; 136 137 // Make sure curr isn't NULL. Because this instruction is being 138 // removed from a dependency list, it must have been placed there at 139 // an earlier time. The dependency chain should not be empty, 140 // unless the instruction dependent upon it is already ready. 141 if (curr == NULL) { 142 return; 143 } 144 145 nodesRemoved++; 146 147 // Find the instruction to remove within the dependency linked list. 148 while (curr->inst != inst_to_remove) { 149 prev = curr; 150 curr = curr->next; 151 nodesTraversed++; 152 153 assert(curr != NULL); 154 } 155 156 // Now remove this instruction from the list. 157 prev->next = curr->next; 158 159 --memAllocCounter; 160 161 // Could push this off to the destructor of DependencyEntry 162 curr->inst = NULL; 163 164 delete curr; 165} 166 167template <class DynInstPtr> 168DynInstPtr 169DependencyGraph<DynInstPtr>::pop(PhysRegIndex idx) 170{ 171 DepEntry *node; 172 node = dependGraph[idx].next; 173 DynInstPtr inst = NULL; 174 if (node) { 175 inst = node->inst; 176 dependGraph[idx].next = node->next; 177 node->inst = NULL; 178 memAllocCounter--; 179 delete node; 180 } 181 return inst; 182} 183 184template <class DynInstPtr> 185void 186DependencyGraph<DynInstPtr>::dump() 187{ 188 DepEntry *curr; 189 190 for (int i = 0; i < numEntries; ++i) 191 { 192 curr = &dependGraph[i]; 193 194 if (curr->inst) { 195 cprintf("dependGraph[%i]: producer: %#x [sn:%lli] consumer: ", 196 i, curr->inst->readPC(), curr->inst->seqNum); 197 } else { 198 cprintf("dependGraph[%i]: No producer. consumer: ", i); 199 } 200 201 while (curr->next != NULL) { 202 curr = curr->next; 203 204 cprintf("%#x [sn:%lli] ", 205 curr->inst->readPC(), curr->inst->seqNum); 206 } 207 208 cprintf("\n"); 209 } 210 cprintf("memAllocCounter: %i\n", memAllocCounter); 211} 212 213#endif // __CPU_O3_DEP_GRAPH_HH__ 214