Fix usage of literal cloning for large double arrays.

src/code-stubs.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_CODE_STUBS_H_
 #define V8_CODE_STUBS_H_
 
 #include "src/allocation.h"
 #include "src/assembler.h"
 #include "src/codegen.h"
 #include "src/globals.h"
 #include "src/ic/ic-state.h"
 #include "src/interface-descriptors.h"
 #include "src/macro-assembler.h"
 #include "src/ostreams.h"
 #include "src/type-hints.h"
 
 namespace v8 {
 namespace internal {
 
 // Forward declarations.
+class ArrayLiteral;
 class CodeStubAssembler;
 class ObjectLiteral;
 namespace compiler {
 class CodeAssemblerLabel;
 class CodeAssemblerState;
 class Node;
 }
 
 // List of code stubs used on all platforms.
 #define CODE_STUB_LIST_ALL_PLATFORMS(V)       \
@@ skipping 884 matching lines @@
                                   compiler::Node* flags,
                                   compiler::Node* context);
 
  private:
   DEFINE_CALL_INTERFACE_DESCRIPTOR(FastCloneRegExp);
   DEFINE_TURBOFAN_CODE_STUB(FastCloneRegExp, TurboFanCodeStub);
 };
 
 class FastCloneShallowArrayStub : public TurboFanCodeStub {
  public:
+  // Maximum number of elements in copied array (chosen so that even an array
+  // backed by a double backing store will fit into new-space).
+  static const int kMaximumClonedElements =
+      JSArray::kInitialMaxFastElementArray * kPointerSize / kDoubleSize;
+
   FastCloneShallowArrayStub(Isolate* isolate,
                             AllocationSiteMode allocation_site_mode)
       : TurboFanCodeStub(isolate) {
     minor_key_ = AllocationSiteModeBits::encode(allocation_site_mode);
   }
 
   static compiler::Node* Generate(CodeStubAssembler* assembler,
                                   compiler::Node* closure,
                                   compiler::Node* literal_index,
                                   compiler::Node* context,
                                   compiler::CodeAssemblerLabel* call_runtime,
                                   AllocationSiteMode allocation_site_mode);
 
+  static bool IsSupported(ArrayLiteral* expr);
+
   AllocationSiteMode allocation_site_mode() const {
     return AllocationSiteModeBits::decode(minor_key_);
   }
 
  private:
   class AllocationSiteModeBits: public BitField<AllocationSiteMode, 0, 1> {};
 
   DEFINE_CALL_INTERFACE_DESCRIPTOR(FastCloneShallowArray);
   DEFINE_TURBOFAN_CODE_STUB(FastCloneShallowArray, TurboFanCodeStub);
 };
@@ skipping 1694 matching lines @@
 #undef DEFINE_PLATFORM_CODE_STUB
 #undef DEFINE_HANDLER_CODE_STUB
 #undef DEFINE_HYDROGEN_CODE_STUB
 #undef DEFINE_CODE_STUB
 #undef DEFINE_CODE_STUB_BASE
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_CODE_STUBS_H_