Convert FastNewClosureStub into hydrogen.

src/code-stubs-hydrogen.cc

Index: src/code-stubs-hydrogen.cc
diff --git a/src/code-stubs-hydrogen.cc b/src/code-stubs-hydrogen.cc
index 3e18138eb2b459bc9b0f56392aae3334d2b643f6..7daf0988d29d7595c6c6f3760bdd877c6dd99590 100644
--- a/src/code-stubs-hydrogen.cc
+++ b/src/code-stubs-hydrogen.cc
@@ -112,6 +112,15 @@ class CodeStubGraphBuilderBase : public HGraphBuilder {
   HValue* BuildInternalArrayConstructor(ElementsKind kind,
                                         ArgumentClass argument_class);
 
+  void InstallCode(HValue* js_function, HValue* native_context,

[Michael Starzinger, 2013/08/27 08:12:51]

nit: Can we prefix these methods with either "Build" or "Emit" to make it clear
that they don't actually "do what they say" but "emit code that does what they
say"?

[mvstanton, 2013/08/27 09:23:04]

Done.

+                   HValue* code_object);
+  void StoreCodeEntry(HValue* js_function, HValue* shared_info,
+                      HValue* undefined_value);
+  void InstallOptimizedClosure(HValue* js_function,
+                               HValue* shared_info,
+                               HValue* native_context,
+                               HValue* undefined_value);
+
  private:
   HValue* BuildArraySingleArgumentConstructor(JSArrayBuilder* builder);
   HValue* BuildArrayNArgumentsConstructor(JSArrayBuilder* builder,
@@ -904,4 +913,200 @@ Handle<Code> ElementsTransitionAndStoreStub::GenerateCode() {
 }
 
 
+void CodeStubGraphBuilderBase::InstallCode(HValue* js_function,

[Michael Starzinger, 2013/08/27 08:12:51]

suggestion: How about calling this method "EmitInstallOptimizedCode" and the one
below "EmitInstallCode", that would make their relationship clearer.

[mvstanton, 2013/08/27 09:23:04]

Good idea. Though I use "Build" instead of "Emit," because
CodeStubGraphBuilderBase already has a collection of "Build" helpers for array
functions; it seems more consistent with this file.

+                                           HValue* native_context,
+                                           HValue* code_object) {
+  Counters* counters = isolate()->counters();
+  AddIncrementCounter(counters->fast_new_closure_install_optimized(),
+                      context());
+
+  // TODO(fschneider): Idea: store proper code pointers in the optimized code
+  // map and either unmangle them on marking or do nothing as the whole map is
+  // discarded on major GC anyway.
+  Add<HStoreCodeEntry>(js_function, code_object);
+
+  // Now link a function into a list of optimized functions.
+  // No need for write barrier as JSFunction object is in the new space.

[Michael Starzinger, 2013/08/27 08:12:51]

nit: The second sentence of the comment is obsolete. Crankshaft is smart enough
to figure that out on it's own, no need to worry about WBs here.

[mvstanton, 2013/08/27 09:23:04]

Done.

+  HValue* optimized_functions_list = Add<HLoadNamedField>(native_context,
+      HObjectAccess::ForContextSlot(Context::OPTIMIZED_FUNCTIONS_LIST));
+  Add<HStoreNamedField>(js_function,
+                        HObjectAccess::ForNextFunctionLinkPointer(),
+                        optimized_functions_list);
+
+  // This store is the only one that should have a write barrier.
+  Add<HStoreNamedField>(native_context,
+           HObjectAccess::ForContextSlot(Context::OPTIMIZED_FUNCTIONS_LIST),
+           js_function);
+}
+
+
+void CodeStubGraphBuilderBase::StoreCodeEntry(HValue* js_function,
+                                              HValue* shared_info,
+                                              HValue* undefined_value) {
+  Add<HStoreNamedField>(js_function,
+                        HObjectAccess::ForNextFunctionLinkPointer(),
+                        undefined_value);
+  HValue* code_object = Add<HLoadNamedField>(shared_info,
+                                             HObjectAccess::ForCodeOffset());
+  Add<HStoreCodeEntry>(js_function, code_object);
+}
+
+
+void CodeStubGraphBuilderBase::InstallOptimizedClosure(

[Michael Starzinger, 2013/08/27 08:12:51]

suggestion: This method could be called "EmitSearchOptimizedCodeMap" or
"EmitInstallFromOptimizedCodeMap", that better describes what it does.

[mvstanton, 2013/08/27 09:23:04]

Done.

+    HValue* js_function,
+    HValue* shared_info,
+    HValue* native_context,
+    HValue* undefined_value) {
+  Counters* counters = isolate()->counters();
+  IfBuilder is_optimized(this);
+  HInstruction* optimized_map = Add<HLoadNamedField>(shared_info,
+                                        HObjectAccess::ForOptimizedCodeMap());
+  HValue* null_constant = Add<HConstant>(0);
+  is_optimized.If<HCompareObjectEqAndBranch>(optimized_map, null_constant);
+  is_optimized.Then();
+  {
+    StoreCodeEntry(js_function, shared_info, undefined_value);
+  }
+  is_optimized.Else();
+  {
+    AddIncrementCounter(counters->fast_new_closure_try_optimized(), context());
+    // 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.
+    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());
+      InstallCode(js_function, native_context, code_object);
+    }
+    already_in.Else();
+    {
+      HValue* shared_function_entry_length =
+          Add<HConstant>(SharedFunctionInfo::kEntryLength);
+      LoopBuilder loop_builder(this,
+                               context(),
+                               LoopBuilder::kPostDecrement,
+                               shared_function_entry_length);
+      HValue* array_length = Add<HLoadNamedField>(optimized_map,
+          HObjectAccess::ForFixedArrayLength());
+      HValue* key = loop_builder.BeginBody(array_length,
+                                           graph()->GetConstant0(),
+                                           Token::GT);
+      {
+        // Iterate through the rest of map backwards.
+        // Do not double check first entry.
+        HValue* second_entry_index =
+            Add<HConstant>(SharedFunctionInfo::kSecondEntryIndex);
+        IfBuilder restore_check(this);
+        restore_check.If<HCompareNumericAndBranch>(key, second_entry_index,
+                                                   Token::EQ);
+        restore_check.Then();
+        {
+          // Store the unoptimized code
+          StoreCodeEntry(js_function, shared_info, undefined_value);
+          loop_builder.Break();
+        }
+        restore_check.Else();
+        {
+          HValue* keyed_minus = AddInstruction(HSub::New(zone(), context(), key,
+              shared_function_entry_length));
+          HInstruction* keyed_lookup = Add<HLoadKeyed>(optimized_map,
+              keyed_minus, static_cast<HValue*>(NULL), FAST_ELEMENTS);
+          IfBuilder done_check(this);
+          done_check.If<HCompareObjectEqAndBranch>(native_context,
+                                                   keyed_lookup);
+          done_check.Then();
+          {
+            // Hit: fetch the optimized code.
+            HValue* keyed_plus = AddInstruction(HAdd::New(zone(), context(),
+                keyed_minus, graph()->GetConstant1()));
+            HValue* code_object = Add<HLoadKeyed>(optimized_map,
+                keyed_plus, static_cast<HValue*>(NULL), FAST_ELEMENTS);
+            InstallCode(js_function, native_context, code_object);
+
+            // Fall out of the loop
+            loop_builder.Break();
+          }
+          done_check.Else();
+          done_check.End();
+        }
+        restore_check.End();
+      }
+      loop_builder.EndBody();
+    }
+    already_in.End();
+  }
+  is_optimized.End();
+}
+
+
+template<>
+HValue* CodeStubGraphBuilder<FastNewClosureStub>::BuildCodeStub() {
+  Counters* counters = isolate()->counters();
+  Factory* factory = isolate()->factory();
+  HInstruction* empty_fixed_array =
+      Add<HConstant>(factory->empty_fixed_array());
+  HInstruction* undefined_value = Add<HConstant>(factory->undefined_value());

[Michael Starzinger, 2013/08/27 08:12:51]

Use graph()->GetConstantUndefined() to get to the "undefined" constant. This
also spares you the trouble of passing it around everywhere.

[mvstanton, 2013/08/27 09:23:04]

Done.

+  HValue* shared_info = GetParameter(0);
+
+  // Create a new closure from the given function info in new space
+  HValue* size = Add<HConstant>(JSFunction::kSize);
+  HInstruction* js_function = Add<HAllocate>(size, HType::JSObject(),
+                                             NOT_TENURED, JS_FUNCTION_TYPE);
+  AddIncrementCounter(counters->fast_new_closure_total(), context());
+
+  int map_index = Context::FunctionMapIndex(casted_stub()->language_mode(),
+                                            casted_stub()->is_generator());
+
+  // Compute the function map in the current native context and set that
+  // as the map of the allocated object.
+  HInstruction* native_context = BuildGetNativeContext();
+  HInstruction* map_slot_value = Add<HLoadNamedField>(native_context,
+      HObjectAccess::ForContextSlot(map_index));
+  Add<HStoreNamedField>(js_function, HObjectAccess::ForMap(), map_slot_value);
+
+  // Initialize the rest of the function. We don't have to update the

[Michael Starzinger, 2013/08/27 08:12:51]

nit: The second sentence of the comment is obsolete. Crankshaft is smart enough
to figure that out on it's own, no need to worry about WBs here.

[mvstanton, 2013/08/27 09:23:04]

Done.

+  // write barrier because the allocated object is in new space.
+  Add<HStoreNamedField>(js_function, HObjectAccess::ForPropertiesPointer(),
+                        empty_fixed_array);
+  Add<HStoreNamedField>(js_function, HObjectAccess::ForElementsPointer(),
+                        empty_fixed_array);
+  Add<HStoreNamedField>(js_function, HObjectAccess::ForLiteralsPointer(),
+                        empty_fixed_array);
+  HInstruction* the_hole = Add<HConstant>(factory->the_hole_value());

[Michael Starzinger, 2013/08/27 08:12:51]

Use graph()->GetConstantHole() here instead.

[mvstanton, 2013/08/27 09:23:04]

Done.

+  Add<HStoreNamedField>(js_function, HObjectAccess::ForPrototypeOrInitialMap(),
+                        the_hole);
+  Add<HStoreNamedField>(js_function,
+                        HObjectAccess::ForSharedFunctionInfoPointer(),
+                        shared_info);
+  Add<HStoreNamedField>(js_function, HObjectAccess::ForFunctionContextPointer(),
+                        shared_info);
+  Add<HStoreNamedField>(js_function, HObjectAccess::ForFunctionContextPointer(),
+                        context());
+
+  // Initialize the code pointer in the function to be the one
+  // found in the shared function info object.
+  // But first check if there is an optimized version for our context.
+  if (FLAG_cache_optimized_code) {
+    InstallOptimizedClosure(js_function, shared_info, native_context,
+                            undefined_value);
+  } else {
+    StoreCodeEntry(js_function, shared_info, undefined_value);
+  }
+
+  return js_function;
+}
+
+
+Handle<Code> FastNewClosureStub::GenerateCode() {
+  return DoGenerateCode(this);
+}
+
+
 } }  // namespace v8::internal