Reduce register pressure in some runtime functions

src/heap.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 4030 matching lines @@
   function->set_context(undefined_value());
   function->set_literals_or_bindings(empty_fixed_array());
   function->set_next_function_link(undefined_value());
 }
 
 
 MaybeObject* Heap::AllocateFunctionPrototype(JSFunction* function) {
   // Make sure to use globals from the function's context, since the function
   // can be from a different context.
   Context* native_context = function->context()->native_context();
-  bool needs_constructor_property;
   Map* new_map;
   if (function->shared()->is_generator()) {
     // Generator prototypes can share maps since they don't have "constructor"
     // properties.
     new_map = native_context->generator_object_prototype_map();
-    needs_constructor_property = false;
   } else {
     // Each function prototype gets a fresh map to avoid unwanted sharing of
     // maps between prototypes of different constructors.
     JSFunction* object_function = native_context->object_function();
     ASSERT(object_function->has_initial_map());
     MaybeObject* maybe_map = object_function->initial_map()->Copy();
     if (!maybe_map->To(&new_map)) return maybe_map;
-    needs_constructor_property = true;
   }
 
   Object* prototype;
   MaybeObject* maybe_prototype = AllocateJSObjectFromMap(new_map);
   if (!maybe_prototype->ToObject(&prototype)) return maybe_prototype;
 
-  if (needs_constructor_property) {
+  if (!function->shared()->is_generator()) {
     MaybeObject* maybe_failure =
         JSObject::cast(prototype)->SetLocalPropertyIgnoreAttributes(
             constructor_string(), function, DONT_ENUM);
     if (maybe_failure->IsFailure()) return maybe_failure;
   }
 
   return prototype;
 }
 
 
@@ skipping 119 matching lines @@
   map->set_unused_property_fields(in_object_properties);
   map->set_prototype(prototype);
   ASSERT(map->has_fast_object_elements());
 
   // If the function has only simple this property assignments add
   // field descriptors for these to the initial map as the object
   // cannot be constructed without having these properties.  Guard by
   // the inline_new flag so we only change the map if we generate a
   // specialized construct stub.
   ASSERT(in_object_properties <= Map::kMaxPreAllocatedPropertyFields);
-  if (instance_type == JS_OBJECT_TYPE &&
+  if (!fun->shared()->is_generator() &&
       fun->shared()->CanGenerateInlineConstructor(prototype)) {
     int count = fun->shared()->this_property_assignments_count();
     if (count > in_object_properties) {
       // Inline constructor can only handle inobject properties.
       fun->shared()->ForbidInlineConstructor();
     } else {
       DescriptorArray* descriptors;
       MaybeObject* maybe_descriptors = DescriptorArray::Allocate(count);
       if (!maybe_descriptors->To(&descriptors)) return maybe_descriptors;
 
@@ skipping 15 matching lines @@
       if (HasDuplicates(descriptors)) {
         fun->shared()->ForbidInlineConstructor();
       } else {
         map->InitializeDescriptors(descriptors);
         map->set_pre_allocated_property_fields(count);
         map->set_unused_property_fields(in_object_properties - count);
       }
     }
   }
 
-  if (instance_type == JS_OBJECT_TYPE) {
+  if (!fun->shared()->is_generator()) {
     fun->shared()->StartInobjectSlackTracking(map);
   }
 
   return map;
 }
 
 
 void Heap::InitializeJSObjectFromMap(JSObject* obj,
                                      FixedArray* properties,
                                      Map* map) {
@@ skipping 3687 matching lines @@
   if (FLAG_parallel_recompilation) {
     heap_->relocation_mutex_->Lock();
 #ifdef DEBUG
     heap_->relocation_mutex_locked_by_optimizer_thread_ =
         heap_->isolate()->optimizing_compiler_thread()->IsOptimizerThread();
 #endif  // DEBUG
   }
 }
 
 } }  // namespace v8::internal