sim: Enable sampling of run-time for code-sections marked using pseudo insts.

This patch adds a mechanism to collect run time samples for specific portions
of a benchmark, using work_begin and work_end pseudo instructions.It also enhances
the histogram stat to report geometric mean.

3 files changed, 12 insertions, 0 deletions

diff --git a/src/base/statistics.hh b/src/base/statistics.hh
index d98c79414..1f8a59326 100644
--- a/src/base/statistics.hh
+++ b/src/base/statistics.hh
@@ -1477,6 +1477,8 @@ class HistStor
 
     /** The current sum. */
     Counter sum;
+    /** The sum of logarithm of each sample, used to compute geometric mean. */
+    Counter logs;
     /** The sum of squares. */
     Counter squares;
     /** The number of samples. */
@@ -1528,6 +1530,7 @@ class HistStor
 
         sum += val * number;
         squares += val * val * number;
+        logs += log(val) * number;
         samples += number;
     }
 
@@ -1567,6 +1570,7 @@ class HistStor
             data.cvec[i] = cvec[i];
 
         data.sum = sum;
+        data.logs = logs;
         data.squares = squares;
         data.samples = samples;
     }
@@ -1589,6 +1593,7 @@ class HistStor
         sum = Counter();
         squares = Counter();
         samples = Counter();
+        logs = Counter();
     }
 };
 
diff --git a/src/base/stats/info.hh b/src/base/stats/info.hh
index 2c5b44a38..98e811747 100644
--- a/src/base/stats/info.hh
+++ b/src/base/stats/info.hh
@@ -183,6 +183,7 @@ struct DistData
     VCounter cvec;
     Counter sum;
     Counter squares;
+    Counter logs;
     Counter samples;
 };
 
diff --git a/src/base/stats/text.cc b/src/base/stats/text.cc
index 683ba7fe4..4cf98ca9e 100644
--- a/src/base/stats/text.cc
+++ b/src/base/stats/text.cc
@@ -367,6 +367,12 @@ DistPrint::operator()(ostream &stream) const
     print.value = data.samples ? data.sum / data.samples : NAN;
     print(stream);
 
+    if (data.type == Hist) {
+        print.name = base + "gmean";
+        print.value = data.samples ? exp(data.logs / data.samples) : NAN;
+        print(stream);
+    }
+
     Result stdev = NAN;
     if (data.samples)
         stdev = sqrt((data.samples * data.squares - data.sum * data.sum) /