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29 #ifndef __SAT_COUNTER_HH__
30 #define __SAT_COUNTER_HH__
34 #include "base/predictor.hh"
36 #include "base/statistics.hh"
37 #include "sim/stats.hh"
41 // A simple saturating counter predictor
44 class SaturatingCounterPred : public GenericPredictor
47 std::string pred_name;
48 std::string zero_name;
52 unsigned counter_bits;
58 unsigned max_value; // maximum counter value
60 unsigned long max_index; // also the index mask value
64 Stats::Scalar<> predicted_one; // Total predictions of one, preds_one
65 Stats::Scalar<> predicted_zero; // Total predictions of zero, preds_zero
66 Stats::Scalar<> correct_pred_one; // Total correct predictions of one, correct_one
67 Stats::Scalar<> correct_pred_zero; // Total correct predictions of zero, correct_zero
69 Stats::Scalar<> record_zero; //updates_zero
70 Stats::Scalar<> record_one; //updates_one
72 Stats::Formula preds_total;
73 Stats::Formula pred_frac_zero;
74 Stats::Formula pred_frac_one;
75 Stats::Formula correct_total;
76 Stats::Formula updates_total;
77 Stats::Formula pred_rate;
78 Stats::Formula frac_correct_zero;
79 Stats::Formula frac_correct_one;
80 Stats::Formula coverage_zero;
81 Stats::Formula coverage_one;
84 bool pred_one(unsigned &counter) { return counter > thresh; }
85 bool pred_zero(unsigned &counter) { return counter <= thresh; }
87 void update_one(unsigned &counter) {
90 counter += one_change;
95 if (counter > max_value)
99 void update_zero(unsigned &counter) {
102 if (counter < zero_change)
105 counter -= zero_change;
113 SaturatingCounterPred(std::string p_name,
114 std::string z_name, std::string o_name,
115 unsigned _index_bits, unsigned _counter_bits = 2,
116 unsigned _zero_change = 1, unsigned _one_change = 1,
117 unsigned _thresh = 1, unsigned _init_value = 0);
120 for (int i = 0; i <= max_index; ++i)
121 table[i] = init_value;
124 // Record the ACTUAL result... and indicate whether the prediction
125 // corresponding to this event was correct
126 void record(unsigned long _index, unsigned _val, unsigned _predicted,
129 record(_index, _val, _predicted);
132 void record(unsigned long _index, unsigned _val, unsigned _predicted) {
133 unsigned long index = _index & max_index;
136 update_one(table[index]);
142 update_zero(table[index]);
150 unsigned value(unsigned long _index) {
151 unsigned long index = _index & max_index;
157 unsigned predict(unsigned long _index, unsigned &pdata) {
158 return predict(_index);
161 unsigned predict(unsigned long _index) {
162 unsigned long index = _index & max_index;
164 if (pred_one(table[index])) {
173 // No internal state is changed here
174 unsigned peek(unsigned long _index) {
175 unsigned long index = _index & max_index;
177 if (pred_one(table[index]))
184 //=======================================================
190 #endif // __SAT_COUNTER_HH__