Line data    Source code

       1             : // Copyright 2016 the V8 project authors. All rights reserved.
       2             : // Use of this source code is governed by a BSD-style license that can be
       3             : // found in the LICENSE file.
       4             : 
       5             : #ifndef V8_BUILTINS_BUILTINS_CONSTRUCTOR_H_
       6             : #define V8_BUILTINS_BUILTINS_CONSTRUCTOR_H_
       7             : 
       8             : #include "src/contexts.h"
       9             : #include "src/objects.h"
      10             : 
      11             : namespace v8 {
      12             : namespace internal {
      13             : 
      14             : class ConstructorBuiltins {
      15             :  public:
      16             :   static int MaximumFunctionContextSlots() {
      17             :     return FLAG_test_small_max_function_context_stub_size ? kSmallMaximumSlots
      18             :                                                           : kMaximumSlots;
      19             :   }
      20             : 
      21             :   // Maximum number of elements in copied array (chosen so that even an array
      22             :   // backed by a double backing store will fit into new-space).
      23             :   static const int kMaximumClonedShallowArrayElements =
      24             :       JSArray::kInitialMaxFastElementArray * kPointerSize / kDoubleSize;
      25             : 
      26             :   // Maximum number of properties in copied objects.
      27             :   static const int kMaximumClonedShallowObjectProperties = 6;
      28             :   static int FastCloneShallowObjectPropertiesCount(int literal_length) {
      29             :     // This heuristic of setting empty literals to have
      30             :     // kInitialGlobalObjectUnusedPropertiesCount must remain in-sync with the
      31             :     // runtime.
      32             :     // TODO(verwaest): Unify this with the heuristic in the runtime.
      33             :     return literal_length == 0
      34             :                ? JSObject::kInitialGlobalObjectUnusedPropertiesCount
      35      347263 :                : literal_length;
      36             :   }
      37             : 
      38             :  private:
      39             :   static const int kMaximumSlots = 0x8000;
      40             :   static const int kSmallMaximumSlots = 10;
      41             : 
      42             :   // FastNewFunctionContext can only allocate closures which fit in the
      43             :   // new space.
      44             :   STATIC_ASSERT(((kMaximumSlots + Context::MIN_CONTEXT_SLOTS) * kPointerSize +
      45             :                  FixedArray::kHeaderSize) < kMaxRegularHeapObjectSize);
      46             : };
      47             : 
      48             : }  // namespace internal
      49             : }  // namespace v8
      50             : 
      51             : #endif  // V8_BUILTINS_BUILTINS_CONSTRUCTOR_H_