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#ifndef __CPU_O3_DEP_GRAPH_HH__
#define __CPU_O3_DEP_GRAPH_HH__
#include "cpu/o3/comm.hh"
template <class DynInstPtr>
class DependencyEntry
{
public:
DependencyEntry()
: inst(NULL), next(NULL)
{ }
DynInstPtr inst;
//Might want to include data about what arch. register the
//dependence is waiting on.
DependencyEntry<DynInstPtr> *next;
};
template <class DynInstPtr>
class DependencyGraph
{
public:
typedef DependencyEntry<DynInstPtr> DepEntry;
DependencyGraph()
: numEntries(0), memAllocCounter(0), nodesTraversed(0), nodesRemoved(0)
{ }
void resize(int num_entries);
void reset();
void insert(PhysRegIndex idx, DynInstPtr &new_inst);
void setInst(PhysRegIndex idx, DynInstPtr &new_inst)
{ dependGraph[idx].inst = new_inst; }
void clearInst(PhysRegIndex idx)
{ dependGraph[idx].inst = NULL; }
void remove(PhysRegIndex idx, DynInstPtr &inst_to_remove);
DynInstPtr pop(PhysRegIndex idx);
bool empty(PhysRegIndex idx) { return !dependGraph[idx].next; }
/** Debugging function to dump out the dependency graph.
*/
void dump();
private:
/** Array of linked lists. Each linked list is a list of all the
* instructions that depend upon a given register. The actual
* register's index is used to index into the graph; ie all
* instructions in flight that are dependent upon r34 will be
* in the linked list of dependGraph[34].
*/
DepEntry *dependGraph;
int numEntries;
// Debug variable, remove when done testing.
unsigned memAllocCounter;
public:
uint64_t nodesTraversed;
uint64_t nodesRemoved;
};
template <class DynInstPtr>
void
DependencyGraph<DynInstPtr>::resize(int num_entries)
{
numEntries = num_entries;
dependGraph = new DepEntry[numEntries];
}
template <class DynInstPtr>
void
DependencyGraph<DynInstPtr>::reset()
{
// Clear the dependency graph
DepEntry *curr;
DepEntry *prev;
for (int i = 0; i < numEntries; ++i) {
curr = dependGraph[i].next;
while (curr) {
memAllocCounter--;
prev = curr;
curr = prev->next;
prev->inst = NULL;
delete prev;
}
if (dependGraph[i].inst) {
dependGraph[i].inst = NULL;
}
dependGraph[i].next = NULL;
}
}
template <class DynInstPtr>
void
DependencyGraph<DynInstPtr>::insert(PhysRegIndex idx, DynInstPtr &new_inst)
{
//Add this new, dependent instruction at the head of the dependency
//chain.
// First create the entry that will be added to the head of the
// dependency chain.
DepEntry *new_entry = new DepEntry;
new_entry->next = dependGraph[idx].next;
new_entry->inst = new_inst;
// Then actually add it to the chain.
dependGraph[idx].next = new_entry;
++memAllocCounter;
}
template <class DynInstPtr>
void
DependencyGraph<DynInstPtr>::remove(PhysRegIndex idx,
DynInstPtr &inst_to_remove)
{
DepEntry *prev = &dependGraph[idx];
DepEntry *curr = dependGraph[idx].next;
// Make sure curr isn't NULL. Because this instruction is being
// removed from a dependency list, it must have been placed there at
// an earlier time. The dependency chain should not be empty,
// unless the instruction dependent upon it is already ready.
if (curr == NULL) {
return;
}
nodesRemoved++;
// Find the instruction to remove within the dependency linked list.
while (curr->inst != inst_to_remove) {
prev = curr;
curr = curr->next;
nodesTraversed++;
assert(curr != NULL);
}
// Now remove this instruction from the list.
prev->next = curr->next;
--memAllocCounter;
// Could push this off to the destructor of DependencyEntry
curr->inst = NULL;
delete curr;
}
template <class DynInstPtr>
DynInstPtr
DependencyGraph<DynInstPtr>::pop(PhysRegIndex idx)
{
DepEntry *node;
node = dependGraph[idx].next;
DynInstPtr inst = NULL;
if (node) {
inst = node->inst;
dependGraph[idx].next = node->next;
node->inst = NULL;
memAllocCounter--;
delete node;
}
return inst;
}
template <class DynInstPtr>
void
DependencyGraph<DynInstPtr>::dump()
{
DepEntry *curr;
for (int i = 0; i < numEntries; ++i)
{
curr = &dependGraph[i];
if (curr->inst) {
cprintf("dependGraph[%i]: producer: %#x [sn:%lli] consumer: ",
i, curr->inst->readPC(), curr->inst->seqNum);
} else {
cprintf("dependGraph[%i]: No producer. consumer: ", i);
}
while (curr->next != NULL) {
curr = curr->next;
cprintf("%#x [sn:%lli] ",
curr->inst->readPC(), curr->inst->seqNum);
}
cprintf("\n");
}
cprintf("memAllocCounter: %i\n", memAllocCounter);
}
#endif // __CPU_O3_DEP_GRAPH_HH__
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