First implementation of allocation elimination in Hydrogen.

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
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 //     * Redistributions in binary form must reproduce the above
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@@ skipping 4494 matching lines @@
   // Initialize the JSObject.
   InitializeJSObjectFromMap(JSObject::cast(obj),
                             FixedArray::cast(properties),
                             map);
   ASSERT(JSObject::cast(obj)->HasFastElements() ||
          JSObject::cast(obj)->HasExternalArrayElements());
   return obj;
 }
 
 
-MaybeObject* Heap::AllocateJSObjectFromMapWithAllocationSite(Map* map,
-    Handle<AllocationSite> allocation_site) {
+MaybeObject* Heap::AllocateJSObjectFromMapForDeoptimizer(
+    Map* map, PretenureFlag pretenure) {

[titzer, 2013/08/06 12:15:47]

Seems to be a lot of overlap with the above function. Can we factor that out
somehow, maybe even have one function that can do both? 

[Michael Starzinger, 2013/08/07 10:51:16]

Done. Merged together and added a flag.

   // JSFunctions should be allocated using AllocateFunction to be
   // properly initialized.
   ASSERT(map->instance_type() != JS_FUNCTION_TYPE);
+
+  // Both types of global objects should be allocated using
+  // AllocateGlobalObject to be properly initialized.
+  ASSERT(map->instance_type() != JS_GLOBAL_OBJECT_TYPE);
+  ASSERT(map->instance_type() != JS_BUILTINS_OBJECT_TYPE);
+
+  // Allocate the JSObject.
+  AllocationSpace space =
+      (pretenure == TENURED) ? OLD_POINTER_SPACE : NEW_SPACE;
+  if (map->instance_size() > Page::kMaxNonCodeHeapObjectSize) space = LO_SPACE;
+  Object* obj;
+  MaybeObject* maybe_obj = Allocate(map, space);
+  if (!maybe_obj->To(&obj)) return maybe_obj;
+
+  // Initialize the JSObject.
+  InitializeJSObjectFromMap(JSObject::cast(obj),
+                            empty_fixed_array(),
+                            map);
+  ASSERT(JSObject::cast(obj)->HasFastElements() ||
+         JSObject::cast(obj)->HasExternalArrayElements());
+  return obj;
+}
+
+
+MaybeObject* Heap::AllocateJSObjectFromMapWithAllocationSite(
+    Map* map, Handle<AllocationSite> allocation_site) {
+  // JSFunctions should be allocated using AllocateFunction to be
+  // properly initialized.
+  ASSERT(map->instance_type() != JS_FUNCTION_TYPE);
 
   // Both types of global objects should be allocated using
   // AllocateGlobalObject to be properly initialized.
   ASSERT(map->instance_type() != JS_GLOBAL_OBJECT_TYPE);
   ASSERT(map->instance_type() != JS_BUILTINS_OBJECT_TYPE);
 
   // Allocate the backing storage for the properties.
   int prop_size = map->InitialPropertiesLength();
   ASSERT(prop_size >= 0);
   Object* properties;
@@ skipping 3501 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