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31 #ifndef __CPU_O3_FU_POOL_HH__
32 #define __CPU_O3_FU_POOL_HH__
39 #include "base/sched_list.hh"
40 #include "cpu/op_class.hh"
41 #include "params/FUPool.hh"
42 #include "sim/sim_object.hh"
48 * Pool of FU's, specific to the new CPU model. The old FU pool had lists of
49 * free units and busy units, and whenever a FU was needed it would iterate
50 * through the free units to find a FU that provided the capability. This pool
51 * has lists of units specific to each of the capabilities, and whenever a FU
52 * is needed, it iterates through that list to find a free unit. The previous
53 * FU pool would have to be ticked each cycle to update which units became
54 * free. This FU pool lets the IEW stage handle freeing units, which frees
55 * them as their scheduled execution events complete. This limits units in this
56 * model to either have identical issue and op latencies, or 1 cycle issue
59 class FUPool : public SimObject
62 /** Maximum op execution latencies, per op class. */
63 unsigned maxOpLatencies[Num_OpClasses];
64 /** Maximum issue latencies, per op class. */
65 unsigned maxIssueLatencies[Num_OpClasses];
67 /** Bitvector listing capabilities of this FU pool. */
68 std::bitset<Num_OpClasses> capabilityList;
70 /** Bitvector listing which FUs are busy. */
71 std::vector<bool> unitBusy;
73 /** List of units to be freed at the end of this cycle. */
74 std::vector<int> unitsToBeFreed;
77 * Class that implements a circular queue to hold FU indices. The hope is
78 * that FUs that have been just used will be moved to the end of the queue
79 * by iterating through it, thus leaving free units at the head of the
84 /** Constructs a circular queue of FU indices. */
89 /** Adds a FU to the queue. */
90 inline void addFU(int fu_idx);
92 /** Returns the index of the FU at the head of the queue, and changes
93 * the index to the next element.
98 /** Circular queue index. */
101 /** Size of the queue. */
104 /** Queue of FU indices. */
105 std::vector<int> funcUnitsIdx;
108 /** Per op class queues of FUs that provide that capability. */
109 FUIdxQueue fuPerCapList[Num_OpClasses];
111 /** Number of FUs. */
114 /** Functional units. */
115 std::vector<FuncUnit *> funcUnits;
117 typedef std::vector<FuncUnit *>::iterator fuListIterator;
120 typedef FUPoolParams Params;
121 /** Constructs a FU pool. */
122 FUPool(const Params *p);
125 /** Annotates units that provide memory operations. Included only because
126 * old FU pool provided this function.
128 void annotateMemoryUnits(unsigned hit_latency);
131 * Gets a FU providing the requested capability. Will mark the unit as busy,
132 * but leaves the freeing of the unit up to the IEW stage.
133 * @param capability The capability requested.
134 * @return Returns -2 if the FU pool does not have the capability, -1 if
135 * there is no free FU, and the FU's index otherwise.
137 int getUnit(OpClass capability);
139 /** Frees a FU at the end of this cycle. */
140 void freeUnitNextCycle(int fu_idx);
142 /** Frees all FUs on the list. */
143 void processFreeUnits();
145 /** Returns the total number of FUs. */
146 int size() { return numFU; }
148 /** Debugging function used to dump FU information. */
151 /** Returns the operation execution latency of the given capability. */
152 unsigned getOpLatency(OpClass capability) {
153 return maxOpLatencies[capability];
156 /** Returns the issue latency of the given capability. */
157 unsigned getIssueLatency(OpClass capability) {
158 return maxIssueLatencies[capability];
161 /** Switches out functional unit pool. */
164 /** Takes over from another CPU's thread. */
168 #endif // __CPU_O3_FU_POOL_HH__