Basic array capacity feedback via allocation sites.

src/hydrogen.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_HYDROGEN_H_
 #define V8_HYDROGEN_H_
 
 #include "src/v8.h"
 
 #include "src/accessors.h"
@@ skipping 1729 matching lines @@
                    ElementsKind kind,
                    HValue* constructor_function = NULL);
 
     enum FillMode {
       DONT_FILL_WITH_HOLE,
       FILL_WITH_HOLE
     };
 
     ElementsKind kind() { return kind_; }
     HAllocate* elements_location() { return elements_location_; }
+    HValue* allocation_site() { return allocation_site_payload_; }
 
     HAllocate* AllocateEmptyArray();
     HAllocate* AllocateArray(HValue* capacity,
                              HValue* length_field,
                              FillMode fill_mode = FILL_WITH_HOLE);
     // Use these allocators when capacity could be unknown at compile time
     // but its limit is known. For constant |capacity| the value of
     // |capacity_upper_bound| is ignored and the actual |capacity|
     // value is used as an upper bound.
     HAllocate* AllocateArray(HValue* capacity,
                              int capacity_upper_bound,
                              HValue* length_field,
                              FillMode fill_mode = FILL_WITH_HOLE);
     HAllocate* AllocateArray(HValue* capacity,
                              HConstant* capacity_upper_bound,
                              HValue* length_field,
                              FillMode fill_mode = FILL_WITH_HOLE);
     HValue* GetElementsLocation() { return elements_location_; }
     HValue* EmitMapCode();
 
    private:
     Zone* zone() const { return builder_->zone(); }
     int elements_size() const {
       return IsFastDoubleElementsKind(kind_) ? kDoubleSize : kPointerSize;
     }
     HGraphBuilder* builder() { return builder_; }
     HGraph* graph() { return builder_->graph(); }
-    int initial_capacity() {
-      STATIC_ASSERT(JSArray::kPreallocatedArrayElements > 0);
-      return JSArray::kPreallocatedArrayElements;
-    }
+    HConstant* initial_capacity();
 
     HValue* EmitInternalMapCode();
 
     HGraphBuilder* builder_;
     ElementsKind kind_;
     AllocationSiteMode mode_;
     HValue* allocation_site_payload_;
     HValue* constructor_function_;
     HAllocate* elements_location_;
   };
@@ skipping 1114 matching lines @@
   }
 
  private:
   HGraphBuilder* builder_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_H_