[Interpreter] Report hottest bytecodes in bytecode_dispatches_report.py

tools/ignition/bytecode_dispatches_report.py

Index: tools/ignition/bytecode_dispatches_report.py
diff --git a/tools/ignition/bytecode_dispatches_report.py b/tools/ignition/bytecode_dispatches_report.py
index 2c04bef600e0336e9cb84f21d928b20eb3eb61eb..8b701fd2107b35fd1482addde7df0a24b9d2831d 100755
--- a/tools/ignition/bytecode_dispatches_report.py
+++ b/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 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 dispatch counters 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 handlers 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
@@ -68,6 +71,21 @@ def print_top_counters(dispatches_table, top_count):
     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())
 
@@ -127,10 +145,10 @@ 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",
@@ -140,17 +158,22 @@ def parse_command_line():
   command_line_parser.add_argument(
     "--interactive", "-i",
     action="store_true",
-    help="open an interactive viewer, rather than writing to file"
+    help="open an interactive viewer, instead of writing to file"
+  )
+  command_line_parser.add_argument(
+    "--top-counters", "-t",

[rmcilroy, 2016/04/19 11:18:19]

This is still not a good name - what do counters mean in this context? I
mentioned in a previous CL that top_counters should be changed for the functions
below as well - i.e.:
 >  Also rename the top_counters to top_bytecode_dispatches or similar.

[Stefano Sanfilippo, 2016/04/19 13:10:33]

Done.

+    action="store_true",
+    help="print the top counters"
   )
   command_line_parser.add_argument(
-    "--top_count", "-t",
+    "--top-counters-number", "-n",
     metavar="N",
     type=int,
     default=10,
-    help="print the top N counters (default 10)"
+    help="print N top counters 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 +208,10 @@ def main():
       figure.set_size_inches(program_options.plot_size,
                              program_options.plot_size)
       pyplot.savefig(program_options.output_filename)
+  elif program_options.top_counters:
+    print_top_counters(dispatches_table, program_options.top_counters_number)
   else:
-    print_top_counters(dispatches_table, program_options.top_count)
+    print_top_bytecodes(dispatches_table)
 
 
 if __name__ == "__main__":