Reland "Optimize function across closures."

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 e3cbe7d588cbb19791576f0cbdd73f2c8db22885..89a8b94b4d2d039bd213cc71a0ec464066d36c48 100644
--- a/src/code-stubs-hydrogen.cc
+++ b/src/code-stubs-hydrogen.cc
@@ -1533,47 +1533,67 @@ HValue* CodeStubGraphBuilder<FastNewClosureStub>::BuildCodeStub() {
 
   AddIncrementCounter(counters->fast_new_closure_total());
 
-  // 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);
-
-  int map_index = Context::FunctionMapIndex(casted_stub()->strict_mode(),
-                                            casted_stub()->kind());
-
-  // 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, static_cast<HValue*>(NULL),
-      HObjectAccess::ForContextSlot(map_index));
-  Add<HStoreNamedField>(js_function, HObjectAccess::ForMap(), map_slot_value);
-
-  // Initialize the rest of the function.
-  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);
-  Add<HStoreNamedField>(js_function, HObjectAccess::ForPrototypeOrInitialMap(),
-                        graph()->GetConstantHole());
-  Add<HStoreNamedField>(js_function,
-                        HObjectAccess::ForSharedFunctionInfoPointer(),
-                        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) {
-    BuildInstallFromOptimizedCodeMap(js_function, shared_info, native_context);
-  } else {
-    BuildInstallCode(js_function, shared_info);
+  IfBuilder optimize_now(this);
+  HInstruction* compile_hint = Add<HLoadNamedField>(
+      shared_info, static_cast<HValue*>(NULL), HObjectAccess::ForCompileHint());
+  HValue* hint_mask = Add<HConstant>(
+      static_cast<int32_t>(1 << SharedFunctionInfo::kOptimizeNextClosure));
+  HInstruction* optimize =
+      AddUncasted<HBitwise>(Token::BIT_AND, compile_hint, hint_mask);
+  optimize_now.If<HCompareNumericAndBranch>(optimize, hint_mask, Token::EQ);
+  optimize_now.Then();
+  {
+    Add<HPushArguments>(context(), shared_info, graph()->GetConstantFalse());
+    Push(Add<HCallRuntime>(isolate()->factory()->empty_string(),
+                           Runtime::FunctionForId(Runtime::kNewClosure), 3));
   }
-
-  return js_function;
+  optimize_now.Else();
+  {
+    // 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);
+
+    int map_index = Context::FunctionMapIndex(casted_stub()->strict_mode(),
+                                              casted_stub()->kind());
+
+    // 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, static_cast<HValue*>(NULL),
+                             HObjectAccess::ForContextSlot(map_index));
+    Add<HStoreNamedField>(js_function, HObjectAccess::ForMap(), map_slot_value);
+
+    // Initialize the rest of the function.
+    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);
+    Add<HStoreNamedField>(js_function,
+                          HObjectAccess::ForPrototypeOrInitialMap(),
+                          graph()->GetConstantHole());
+    Add<HStoreNamedField>(js_function,
+                          HObjectAccess::ForSharedFunctionInfoPointer(),
+                          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) {
+      BuildInstallFromOptimizedCodeMap(js_function, shared_info,
+                                       native_context);
+    } else {
+      BuildInstallCode(js_function, shared_info);
+    }
+    Push(js_function);
+  }
+  optimize_now.End();
+  return Pop();
 }