Use optimized code map to cache OSR code.

src/code-stubs-hydrogen.cc

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 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
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@@ skipping 1171 matching lines @@
   is_optimized.Then();
   {
     BuildInstallCode(js_function, shared_info);
   }
   is_optimized.Else();
   {
     AddIncrementCounter(counters->fast_new_closure_try_optimized());
     // optimized_map points to fixed array of 3-element entries
     // (native context, optimized code, literals).
     // Map must never be empty, so check the first elements.
+    // Matching code that we find may have been compiled for OSR as opposed to
+    // regular optimized code.  That is probably because we never had the
+    // chance to compile regular optimized code before OSR engaged.  In that
+    // case, it's probably a good idea to just reuse that OSR code right now.

[Michael Starzinger, 2013/12/03 15:27:32]

I strongly disagree that this is a good idea! Once Ben's work is done, it will
be incorrect to do that. This will just take whatever code is in the
optimized_map and smash it into the JSFunction. OSR code should not be installed
into JSFunctions at all.

     Label install_optimized;
     HValue* first_context_slot = Add<HLoadNamedField>(optimized_map,
         HObjectAccess::ForFirstContextSlot());
     IfBuilder already_in(this);
     already_in.If<HCompareObjectEqAndBranch>(native_context,
                                              first_context_slot);
     already_in.Then();
     {
       HValue* code_object = Add<HLoadNamedField>(optimized_map,
         HObjectAccess::ForFirstCodeSlot());
@@ skipping 128 matching lines @@
   return BuildUncheckedDictionaryElementLoad(receiver, key);
 }
 
 
 Handle<Code> KeyedLoadDictionaryElementStub::GenerateCode(Isolate* isolate) {
   return DoGenerateCode(isolate, this);
 }
 
 
 } }  // namespace v8::internal