ext: add the source code for DSENT

This patch adds a tool called DSENT to the ext/ directory.  DSENT
is a tool that models power and area for on-chip networks.  The next
patch adds a script for using the tool.

1 files changed, 70 insertions, 0 deletions

diff --git a/ext/dsent/model/TransitionInfo.cc b/ext/dsent/model/TransitionInfo.cc
new file mode 100644
index 000000000..ac4402060
--- /dev/null
+++ b/ext/dsent/model/TransitionInfo.cc
@@ -0,0 +1,70 @@
+#include "model/TransitionInfo.h"
+
+namespace DSENT
+{
+    TransitionInfo::TransitionInfo()
+        : m_number_transitions_00_(0.25), m_number_transitions_01_(0.25), 
+        m_number_transitions_11_(0.25), m_frequency_multiplier_(1.0)
+    {
+        update();
+    }
+
+    TransitionInfo::TransitionInfo(double number_transitions_00_, double number_transitions_01_,
+            double number_transitions_11_)
+        : m_number_transitions_00_(number_transitions_00_), m_number_transitions_01_(number_transitions_01_),
+        m_number_transitions_11_(number_transitions_11_)
+    {
+        m_frequency_multiplier_ = m_number_transitions_00_ + 2.0 * m_number_transitions_01_ + m_number_transitions_11_;
+        update();
+    }
+
+    TransitionInfo::~TransitionInfo()
+    {}
+
+    void TransitionInfo::update()
+    {
+        ASSERT(m_number_transitions_00_ >= 0.0, "[Error] Number of 0->0 transitions (" + 
+                (String)m_number_transitions_00_ + ") must be >= 0.0!");
+        ASSERT(m_number_transitions_01_ >= 0.0, "[Error] Number of 0->1 transitions (" + 
+                (String)m_number_transitions_01_ + ") must be >= 0.0!");
+        ASSERT(m_number_transitions_11_ >= 0.0, "[Error] Number of 1->1 transitions (" + (String)m_number_transitions_11_ + ") must be >= 0.0!");
+
+        m_probability_1_ = (m_number_transitions_01_ + m_number_transitions_11_) / m_frequency_multiplier_;
+        m_probability_0_ = 1.0 - m_probability_1_;
+        return;
+    }
+
+    TransitionInfo TransitionInfo::scaleFrequencyMultiplier(double frequency_multiplier_) const
+    {
+        // A short cut if frequency_multiplier_ == m_frequency_multiplier_ to avoid excess calculations
+        if(frequency_multiplier_ == m_frequency_multiplier_)
+        {
+            return TransitionInfo(m_number_transitions_00_, m_number_transitions_01_, m_number_transitions_11_);
+        }
+        else if (frequency_multiplier_ > m_frequency_multiplier_)
+        {
+            double freq_ratio = frequency_multiplier_ / m_frequency_multiplier_;
+            double diff_num_trans_01 = m_number_transitions_01_ * (freq_ratio - 1.0);
+            double norm_num_trans_00 = m_number_transitions_00_ * freq_ratio + diff_num_trans_01;
+            double norm_num_trans_01 = m_number_transitions_01_;
+            double norm_num_trans_11 = m_number_transitions_11_ * freq_ratio + diff_num_trans_01;
+
+            return TransitionInfo(norm_num_trans_00, norm_num_trans_01, norm_num_trans_11);
+        }
+        else
+        {
+            ASSERT(false, "[Error] Cannot scale to frequency multiplier (" + (String) frequency_multiplier_ +
+                ") since current frequency multiplier (" + (String) m_frequency_multiplier_ + ") is bigger!");
+        }
+    }
+
+    void TransitionInfo::print(std::ostream& ost_) const
+    {
+        ost_ << "[" << m_number_transitions_00_ << ", " << m_number_transitions_01_ << ", " << m_number_transitions_11_ << "]";
+        ost_ << " [" << m_number_transitions_00_ / m_frequency_multiplier_;
+        ost_ << ", " << m_number_transitions_01_*2.0 / m_frequency_multiplier_;
+        ost_ << ", " << m_number_transitions_11_ / m_frequency_multiplier_ << "]" << endl;
+        return;
+    }
+} // namespace DSENT
+