Add deoptimization history to optimized functions.

runtime/vm/compiler.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/compiler.h"
 
 #include "vm/assembler.h"
 
 #include "vm/ast_printer.h"
 #include "vm/code_generator.h"
@@ skipping 355 matching lines @@
       graph_compiler.FinalizeStaticCallTargetsTable(code);
 
       if (optimized) {
         CodePatcher::PatchEntry(Code::Handle(function.CurrentCode()));
         function.SetCode(code);
         if (FLAG_trace_compiler) {
           OS::Print("--> patching entry %#"Px"\n",
                     Code::Handle(function.unoptimized_code()).EntryPoint());
         }
 
+        // If not yet present, allocate deoptimization history array.
+        const Array& deopt_history = Array::Handle(function.deopt_history());

[Kevin Millikin (Google), 2013/05/24 11:39:21]

You can use just one handle here.

Array& deopt_history = Array::Handle(function.deopt_history());
if (deopt_history.IsNull()) {
  deopt_history = Array::New(...);
  function.set_deopt_history(deopt_history);
}

[Florian Schneider, 2013/05/24 11:53:02]

Done.

+        if (deopt_history.IsNull()) {
+          const Array& array =
+              Array::Handle(Array::New(FLAG_deoptimization_counter_threshold));
+          function.set_deopt_history(array);
+        }
+
         for (intptr_t i = 0; i < guarded_fields.length(); i++) {
           const Field& field = *guarded_fields[i];
           field.RegisterDependentCode(code);
         }
       } else {
         function.set_unoptimized_code(code);
         function.SetCode(code);
         ASSERT(CodePatcher::CodeIsPatchable(code));
       }
     }
@@ skipping 350 matching lines @@
       Object::Handle(isolate->object_store()->sticky_error());
     isolate->object_store()->clear_sticky_error();
     isolate->set_long_jump_base(base);
     return result.raw();
   }
   UNREACHABLE();
   return Object::null();
 }
 
 }  // namespace dart