Track allocation info

src/hydrogen.cc

 // Copyright 2012 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
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 7729 matching lines @@
 }
 
 
 // Checks whether allocation using the given constructor can be inlined.
 static bool IsAllocationInlineable(Handle<JSFunction> constructor) {
   return constructor->has_initial_map() &&
       constructor->initial_map()->instance_type() == JS_OBJECT_TYPE &&
       constructor->initial_map()->instance_size() < HAllocateObject::kMaxSize;
 }
 
+static bool IsArrayConstructInlinable(Handle<JSFunction> constructor) {
+  return constructor->GetIsolate()->global_context()->array_function() ==
+      *constructor;
+}
 
 void HGraphBuilder::VisitCallNew(CallNew* expr) {
   ASSERT(!HasStackOverflow());
   ASSERT(current_block() != NULL);
   ASSERT(current_block()->HasPredecessor());
   expr->RecordTypeFeedback(oracle());
   int argument_count = expr->arguments()->length() + 1;  // Plus constructor.
   HValue* context = environment()->LookupContext();
 
   if (FLAG_inline_construct &&
@@ skipping 28 matching lines @@
     // add HPushArgument for the arguments in case inlining failed.  What we
     // actually should do is emit HInvokeFunction on the constructor instead
     // of using HCallNew as a fallback.
     receiver->DeleteAndReplaceWith(NULL);
     check->DeleteAndReplaceWith(NULL);
     environment()->SetExpressionStackAt(receiver_index, function);
     HInstruction* call = PreProcessCall(
         new(zone()) HCallNew(context, function, argument_count));
     call->set_position(expr->position());
     return ast_context()->ReturnInstruction(call, expr->id());
+  } else if (expr->IsMonomorphic() &&
+             argument_count == 1 &&
+             IsArrayConstructInlinable(expr->target())) {
+    CHECK_ALIVE(VisitForValue(expr->expression()));
+    HValue* function = Top();
+    environment()->Drop(1);
+    Handle<JSFunction> constructor = expr->target();
+    ElementsKind elements_kind = expr->elements_kind();
+    AddInstruction(new(zone()) HCheckFunction(function, constructor));
+    Factory* f = graph()->isolate()->factory();
+    Handle<JSArray> boilerplate = f->NewEmptyJSArray(elements_kind, TENURED);
+    HValue* context = environment()->LookupContext();
+    int total_size = JSArray::kSize + FixedArray::kHeaderSize;
+    if (IsFastDoubleElementsKind(elements_kind)) {
+      total_size += boilerplate->elements()->length() * kDoubleSize;
+    } else {
+      total_size += boilerplate->elements()->length() * kPointerSize;
+    }
+    HFastLiteral* empty_array = new(zone()) HFastLiteral(context,
+                                                         boilerplate,
+                                                         total_size,
+                                                         0,
+                                                         0);
+    return ast_context()->ReturnInstruction(empty_array, expr->id());    
   } else {
     // The constructor function is both an operand to the instruction and an
     // argument to the construct call.
     CHECK_ALIVE(VisitArgument(expr->expression()));
     HValue* constructor = HPushArgument::cast(Top())->argument();
     CHECK_ALIVE(VisitArgumentList(expr->arguments()));
     HInstruction* call =
         new(zone()) HCallNew(context, constructor, argument_count);
     Drop(argument_count);
     call->set_position(expr->position());
@@ skipping 2165 matching lines @@
     }
   }
 
 #ifdef DEBUG
   if (graph_ != NULL) graph_->Verify(false);  // No full verify.
   if (allocator_ != NULL) allocator_->Verify();
 #endif
 }
 
 } }  // namespace v8::internal