Merge experimental/gc branch to the bleeding_edge.

tools/ll_prof.py

 #!/usr/bin/env python
 #
 # Copyright 2010 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
@@ skipping 381 matching lines @@
           origin = JS_SNAPSHOT_ORIGIN
         else:
           name = self.log[self.log_pos:self.log_pos + event.name_size]
           origin = JS_ORIGIN
         self.log_pos += event.name_size
         origin_offset = self.log_pos
         self.log_pos += event.code_size
         code = Code(name, start_address, end_address, origin, origin_offset)
         conficting_code = self.code_map.Find(start_address)
         if conficting_code:
-          LogReader._HandleCodeConflict(conficting_code, code)
-          # TODO(vitalyr): this warning is too noisy because of our
-          # attempts to reconstruct code log from the snapshot.
-          # print >>sys.stderr, \
-          #     "Warning: Skipping duplicate code log entry %s" % code
-          continue
+          if not (conficting_code.start_address == code.start_address and
+            conficting_code.end_address == code.end_address):
+            self.code_map.Remove(conficting_code)
+          else:
+            LogReader._HandleCodeConflict(conficting_code, code)
+            # TODO(vitalyr): this warning is too noisy because of our
+            # attempts to reconstruct code log from the snapshot.
+            # print >>sys.stderr, \
+            #     "Warning: Skipping duplicate code log entry %s" % code
+            continue
         self.code_map.Add(code)
         continue
 
       if tag == LogReader._CODE_MOVE_TAG:
         event = self.code_move_struct.from_buffer(self.log, self.log_pos)
         self.log_pos += ctypes.sizeof(event)
         old_start_address = event.from_address
         new_start_address = event.to_address
         if old_start_address == new_start_address:
           # Skip useless code move entries.
@@ skipping 515 matching lines @@
       print "%10d total ticks" % ticks
       print "%10d ticks not in symbols" % missed_ticks
       print "%10d unaccounted ticks" % really_missed_ticks
       print "%10d total symbols" % len([c for c in code_map.AllCode()])
       print "%10d used symbols" % len([c for c in code_map.UsedCode()])
       print "%9.2fs library processing time" % mmap_time
       print "%9.2fs tick processing time" % sample_time
 
   log_reader.Dispose()
   trace_reader.Dispose()