Calculate string hash during flattening.

src/runtime.cc

 // Copyright 2006-2008 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 2362 matching lines @@
   position = 0;
   Object* object;
   if (ascii) {
     object = Heap::AllocateRawAsciiString(length);
   } else {
     object = Heap::AllocateRawTwoByteString(length);
   }
   if (object->IsFailure()) return object;
 
   String* answer = String::cast(object);
+  StringHasher hasher(length);
   for (int i = 0; i < array_length; i++) {
     Object* element = fixed_array->get(i);
     if (element->IsSmi()) {
       int len = Smi::cast(element)->value();
       int pos = len >> 11;
       len &= 0x7ff;
-      String::Flatten(special, answer, pos, pos + len, position);
+      String::Flatten(special, answer, pos, pos + len, position, &hasher);
       position += len;
     } else {
       String* string = String::cast(element);
       int element_length = string->length();
-      String::Flatten(string, answer, 0, element_length, position);
+      String::Flatten(string, answer, 0, element_length, position, &hasher);
       position += element_length;
     }
   }
+  if (hasher.is_valid())
+    answer->set_length_field(hasher.GetHashField());
   return answer;
 }
 
 
 static Object* Runtime_NumberOr(Arguments args) {
   NoHandleAllocation ha;
   ASSERT(args.length() == 2);
 
   CONVERT_NUMBER_CHECKED(int32_t, x, Int32, args[0]);
   CONVERT_NUMBER_CHECKED(int32_t, y, Int32, args[1]);
@@ skipping 2758 matching lines @@
 
 void Runtime::PerformGC(Object* result) {
   Failure* failure = Failure::cast(result);
   // Try to do a garbage collection; ignore it if it fails. The C
   // entry stub will throw an out-of-memory exception in that case.
   Heap::CollectGarbage(failure->requested(), failure->allocation_space());
 }
 
 
 } }  // namespace v8::internal