summaryrefslogtreecommitdiff
path: root/src/base/hybrid_pred.hh
diff options
context:
space:
mode:
Diffstat (limited to 'src/base/hybrid_pred.hh')
-rw-r--r--src/base/hybrid_pred.hh201
1 files changed, 201 insertions, 0 deletions
diff --git a/src/base/hybrid_pred.hh b/src/base/hybrid_pred.hh
new file mode 100644
index 000000000..ea4a9d04c
--- /dev/null
+++ b/src/base/hybrid_pred.hh
@@ -0,0 +1,201 @@
+/*
+ * Copyright (c) 2001-2005 The Regents of The University of Michigan
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met: redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer;
+ * redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution;
+ * neither the name of the copyright holders nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+//==========================================================================
+//
+// This predictor takes the AND of a "local" and a "global" predictor
+// in order to determine its prediction.
+//
+//
+//
+//
+
+#ifndef __HYBRID_PRED_HH__
+#define __HYBRID_PRED_HH__
+
+#include <string>
+
+#include "base/sat_counter.hh"
+#include "base/statistics.hh"
+
+class HybridPredictor : public GenericPredictor
+{
+ private:
+ std::string pred_name;
+ std::string one_name;
+ std::string zero_name;
+ bool reg_individual_stats;
+
+ SaturatingCounterPred *local;
+ SaturatingCounterPred *global;
+
+ unsigned long max_index;
+
+ //
+ // Stats
+ //
+ Stats::Scalar<> pred_one; //num_one_preds
+ Stats::Scalar<> pred_zero; //num_zero_preds
+ Stats::Scalar<> correct_pred_one; //num_one_correct
+ Stats::Scalar<> correct_pred_zero; //num_zero_correct
+ Stats::Scalar<> record_one; //num_one_updates
+ Stats::Scalar<> record_zero; //num_zero_updates
+
+ Stats::Formula total_preds;
+ Stats::Formula frac_preds_zero;
+ Stats::Formula frac_preds_one;
+ Stats::Formula total_correct;
+ Stats::Formula total_accuracy;
+ Stats::Formula zero_accuracy;
+ Stats::Formula one_accuracy;
+ Stats::Formula zero_coverage;
+ Stats::Formula one_coverage;
+
+ public:
+ HybridPredictor(const char *_p_name, const char *_z_name,
+ const char *_o_name,
+ unsigned _index_bits, unsigned _counter_bits,
+ unsigned _zero_change, unsigned _one_change,
+ unsigned _thresh,
+ unsigned _global_bits, unsigned _global_thresh,
+ bool _reg_individual_stats = false);
+
+ void clear() {
+ global->clear();
+ local->clear();
+ }
+
+ unsigned peek(unsigned long _index) {
+ unsigned l = local->peek(_index);
+ unsigned g = global->peek(_index);
+
+ if (l && g)
+ return 1;
+
+ return 0;
+ }
+
+ unsigned value(unsigned long _index) {
+ unsigned l = local->peek(_index);
+ unsigned g = global->peek(_index);
+
+ l = l & 0xFFFF;
+ g = g & 0xFFFF;
+
+ return (l << 16) | g;
+
+ }
+
+ unsigned predict(unsigned long _index) {
+ unsigned l = local->predict(_index);
+ unsigned g = global->predict(_index);
+
+ if (l && g) {
+ ++pred_one;
+ return 1;
+ }
+
+ ++pred_zero;
+ return 0;
+ }
+
+
+ //
+ // This version need only be used if local/global statistics
+ // will be maintained
+ //
+ unsigned predict(unsigned long _index, unsigned &_pdata) {
+ unsigned l = local->predict(_index);
+ unsigned g = global->predict(_index);
+
+ //
+ // bit 0 => local predictor result
+ // bit 1 => global predictor result
+ //
+ _pdata = 0;
+ if (l)
+ _pdata |= 1;
+ if (g)
+ _pdata |= 2;
+ if (l && g) {
+ ++pred_one;
+ return 1;
+ }
+
+ ++pred_zero;
+ return 0;
+ }
+
+ void record(unsigned long _index, unsigned _val, unsigned _predicted) {
+
+ if (_val) {
+ local->record(_index, _val, 0);
+ global->record(_index, _val, 0);
+ ++record_one;
+
+ if (_val == _predicted) {
+ ++correct_pred_one;
+ }
+ } else {
+ local->record(_index, _val, 0);
+ global->record(_index, _val, 0);
+ ++record_zero;
+
+ if (_val == _predicted)
+ ++correct_pred_zero;
+ }
+ }
+
+ void record(unsigned long _index, unsigned _val, unsigned _predicted,
+ unsigned _pdata)
+ {
+
+ local->record(_index, _val, (_pdata & 1));
+ global->record(_index, _val, ((_pdata & 2) ? 1 : 0));
+
+
+ if (_val) {
+ ++record_one;
+
+ if (_val == _predicted)
+ ++correct_pred_one;
+ } else {
+ ++record_zero;
+
+ if (_val == _predicted)
+ ++correct_pred_zero;
+ }
+ }
+
+ void regStats();
+ void regFormulas();
+};
+
+
+#endif // _HYBRID_PRED_HH__
+