[Interpreter] Report hottest bytecodes in bytecode_dispatches_report.py

In addition to top source-destination pairs,
bytecode_dispatches_report.py now prints the hottest bytecode handlers
by the number of times they are executed and dispatch to another one,
regardless of the dispatch target.

Be aware that this figure does not match the number of times a handler
is executed for those which may not or will never dispatch, e.g.
Return or Throw.

BUG=v8:4899
LOG=N

Review URL: https://codereview.chromium.org/1875263004

Cr-Commit-Position: refs/heads/master@{#35629}

tools/ignition/bytecode_dispatches_report.py

@@ -17,17 +17,20 @@ import struct
 __DESCRIPTION = """
 Process v8.ignition_dispatches_counters.json and list top counters,
 or plot a dispatch heatmap.
+
+Please note that those handlers that may not or will never dispatch
+(e.g. Return or Throw) do not show up in the results.
 """
 
 
 __HELP_EPILOGUE = """
 examples:
-  # Print the top 10 counters, reading from default filename
-  # v8.ignition_dispatches_counters.json (default mode)
+  # Print the hottest bytecodes in descending order, reading from
+  # default filename v8.ignition_dispatches_counters.json (default mode)
   $ tools/ignition/bytecode_dispatches_report.py
 
-  # Print the top 15 counters reading from data.json
-  $ tools/ignition/bytecode_dispatches_report.py -t 15 data.json
+  # Print the hottest 15 bytecode dispatch pairs reading from data.json
+  $ tools/ignition/bytecode_dispatches_report.py -t -n 15 data.json
 
   # Save heatmap to default filename v8.ignition_dispatches_counters.svg
   $ tools/ignition/bytecode_dispatches_report.py -p
@@ -51,7 +54,7 @@ def warn_if_counter_may_have_saturated(dispatches_table):
                                                              destination)
 
 
-def find_top_counters(dispatches_table, top_count):
+def find_top_bytecode_dispatch_pairs(dispatches_table, top_count):
   def flattened_counters_generator():
     for source, counters_from_source in dispatches_table.items():
       for destination, counter in counters_from_source.items():
@@ -61,13 +64,29 @@ def find_top_counters(dispatches_table, top_count):
                         key=lambda x: x[2])
 
 
-def print_top_counters(dispatches_table, top_count):
-  top_counters = find_top_counters(dispatches_table, top_count)
-  print "Top {} dispatch counters:".format(top_count)
-  for source, destination, counter in top_counters:
+def print_top_bytecode_dispatch_pairs(dispatches_table, top_count):
+  top_bytecode_dispatch_pairs = (
+    find_top_bytecode_dispatch_pairs(dispatches_table, top_count))
+  print "Top {} bytecode dispatch pairs:".format(top_count)
+  for source, destination, counter in top_bytecode_dispatch_pairs:
     print "{:>12d}\t{} -> {}".format(counter, source, destination)
 
 
+def find_top_bytecodes(dispatches_table):
+  top_bytecodes = []
+  for bytecode, counters_from_bytecode in dispatches_table.items():
+    top_bytecodes.append((bytecode, sum(counters_from_bytecode.values())))
+  top_bytecodes.sort(key=lambda x: x[1], reverse=True)
+  return top_bytecodes
+
+
+def print_top_bytecodes(dispatches_table):
+  top_bytecodes = find_top_bytecodes(dispatches_table)
+  print "Top bytecodes:"
+  for bytecode, counter in top_bytecodes:
+    print "{:>12d}\t{}".format(counter, bytecode)
+
+
 def build_counters_matrix(dispatches_table):
   labels = sorted(dispatches_table.keys())
 
@@ -90,10 +109,10 @@ def plot_dispatches_table(dispatches_table, figure, axis):
 
   image = axis.pcolor(
     counters_matrix,
-    cmap='jet',
+    cmap="jet",
     norm=colors.LogNorm(),
-    edgecolor='grey',
-    linestyle='dotted',
+    edgecolor="grey",
+    linestyle="dotted",
     linewidth=0.5
   )
 
@@ -103,7 +122,7 @@ def plot_dispatches_table(dispatches_table, figure, axis):
   )
   axis.xaxis.tick_top()
   axis.set_xlim(0, len(xlabels))
-  axis.set_xticklabels(xlabels, rotation='vertical')
+  axis.set_xticklabels(xlabels, rotation="vertical")
 
   axis.yaxis.set(
     ticks=numpy.arange(0.5, len(ylabels)),
@@ -127,30 +146,35 @@ def parse_command_line():
     epilog=__HELP_EPILOGUE
   )
   command_line_parser.add_argument(
-    "--plot_size", "-s",
+    "--plot-size", "-s",
     metavar="N",
     default=30,
-    help="shorter side, in inches, of the output plot (default 30)"
+    help="shorter side in inches of the output plot (default 30)"
   )
   command_line_parser.add_argument(
     "--plot", "-p",
     action="store_true",
-    help="plot dispatches table heatmap"
+    help="plot dispatch pairs heatmap"
   )
   command_line_parser.add_argument(
     "--interactive", "-i",
     action="store_true",
-    help="open an interactive viewer, rather than writing to file"
+    help="open the heatmap in an interactive viewer, instead of writing to file"
+  )
+  command_line_parser.add_argument(
+    "--top-bytecode-dispatch-pairs", "-t",
+    action="store_true",
+    help="print the top bytecode dispatch pairs"
   )
   command_line_parser.add_argument(
-    "--top_count", "-t",
+    "--top-bytecode-dispatch-pairs-number", "-n",
     metavar="N",
     type=int,
     default=10,
-    help="print the top N counters (default 10)"
+    help="print N top bytecode dispatch pairs when running with -t (default 10)"
   )
   command_line_parser.add_argument(
-    "--output_filename", "-o",
+    "--output-filename", "-o",
     metavar="<output filename>",
     default="v8.ignition_dispatches_table.svg",
     help=("file to save the plot file to. File type is deduced from the "
@@ -185,8 +209,11 @@ def main():
       figure.set_size_inches(program_options.plot_size,
                              program_options.plot_size)
       pyplot.savefig(program_options.output_filename)
+  elif program_options.top_bytecode_dispatch_pairs:
+    print_top_bytecode_dispatch_pairs(
+      dispatches_table, program_options.top_bytecode_dispatch_pairs_number)
   else:
-    print_top_counters(dispatches_table, program_options.top_count)
+    print_top_bytecodes(dispatches_table)
 
 
 if __name__ == "__main__":

tools/ignition/bytecode_dispatches_report_test.py

@@ -8,7 +8,7 @@ import unittest
 
 class BytecodeDispatchesReportTest(unittest.TestCase):
   def test_find_top_counters(self):
-    top_counters = bdr.find_top_counters({
+    top_counters = bdr.find_top_bytecode_dispatch_pairs({
       "a": {"a": 10, "b": 8, "c": 99},
       "b": {"a":  1, "b": 4, "c":  1},
       "c": {"a": 42, "b": 3, "c":  7}}, 5)
@@ -29,3 +29,15 @@ class BytecodeDispatchesReportTest(unittest.TestCase):
                                          [10,  8,  7]]).all())
     self.assertListEqual(xlabels, ['a', 'b', 'c'])
     self.assertListEqual(ylabels, ['c', 'b', 'a'])
+
+  def test_find_top_bytecodes(self):
+    top_dispatch_sources = bdr.find_top_bytecodes({
+      "a": {"a": 10, "b":  8, "c":  7},
+      "b": {"a":  1, "c":  4},
+      "c": {"a": 42, "b": 12, "c": 99}
+    })
+    self.assertListEqual(top_dispatch_sources, [
+      ('c', 153),
+      ('a',  25),
+      ('b',   5)
+    ])