[Interpreter] Report hottest bytecodes in bytecode_dispatches_report.py

tools/ignition/bytecode_dispatches_report.py

 #! /usr/bin/python
 #
 # Copyright 2016 the V8 project authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 #
 
 import argparse
 import heapq
 import json
 from matplotlib import colors
 from matplotlib import pyplot
 import numpy
 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
 
   # Save heatmap to filename data.svg
   $ tools/ignition/bytecode_dispatches_report.py -p -o data.svg
 
   # Open the heatmap in an interactive viewer
   $ tools/ignition/bytecode_dispatches_report.py -p -i
 """
 
 __COUNTER_BITS = struct.calcsize("P") * 8  # Size in bits of a pointer
 __COUNTER_MAX = 2**__COUNTER_BITS - 1
 
 
 def warn_if_counter_may_have_saturated(dispatches_table):
   for source, counters_from_source in dispatches_table.items():
     for destination, counter in counters_from_source.items():
       if counter == __COUNTER_MAX:
         print "WARNING: {} -> {} may have saturated.".format(source,
                                                              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():
         yield source, destination, counter
 
   return heapq.nlargest(top_count, flattened_counters_generator(),
                         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())
 
   counters_matrix = numpy.empty([len(labels), len(labels)], dtype=int)
   for from_index, from_name in enumerate(labels):
     current_row = dispatches_table[from_name];
     for to_index, to_name in enumerate(labels):
       counters_matrix[from_index, to_index] = current_row.get(to_name, 0)
 
   # Reverse y axis for a nicer appearance
   xlabels = labels
   ylabels = list(reversed(xlabels))
   counters_matrix = numpy.flipud(counters_matrix)
 
   return counters_matrix, xlabels, ylabels
 
 
 def plot_dispatches_table(dispatches_table, figure, axis):
   counters_matrix, xlabels, ylabels = build_counters_matrix(dispatches_table)
 
   image = axis.pcolor(
     counters_matrix,
-    cmap='jet',
+    cmap="jet",
     norm=colors.LogNorm(),
-    edgecolor='grey',
-    linestyle='dotted',
+    edgecolor="grey",
+    linestyle="dotted",
     linewidth=0.5
   )
 
   axis.xaxis.set(
     ticks=numpy.arange(0.5, len(xlabels)),
     label="From bytecode handler"
   )
   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)),
     label="To bytecode handler",
     ticklabels=ylabels
   )
   axis.set_ylim(0, len(ylabels))
 
   figure.colorbar(
     image,
     ax=axis,
     fraction=0.01,
     pad=0.01
   )
 
 
 def parse_command_line():
   command_line_parser = argparse.ArgumentParser(
     formatter_class=argparse.RawDescriptionHelpFormatter,
     description=__DESCRIPTION,
     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_count", "-t",
+    "--top-bytecode-dispatch-pairs", "-t",
+    action="store_true",
+    help="print the top bytecode dispatch pairs"
+  )
+  command_line_parser.add_argument(
+    "--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 "
           "extension. PDF, SVG, PNG supported")
   )
   command_line_parser.add_argument(
     "input_filename",
     metavar="<input filename>",
     default="v8.ignition_dispatches_table.json",
     nargs='?',
@@ skipping 14 matching lines @@
   if program_options.plot:
     figure, axis = pyplot.subplots()
     plot_dispatches_table(dispatches_table, figure, axis)
 
     if program_options.interactive:
       pyplot.show()
     else:
       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__":
   main()