X64: Convert smis to holding 32 bits of payload.

src/heap.cc

 // Copyright 2009 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 1661 matching lines @@
   if (first_length == 0) return second;
 
   int second_length = second->length();
   if (second_length == 0) return first;
 
   int length = first_length + second_length;
   bool is_ascii = first->IsAsciiRepresentation()
       && second->IsAsciiRepresentation();
 
   // Make sure that an out of memory exception is thrown if the length
-  // of the new cons string is too large to fit in a Smi.
-  if (length > Smi::kMaxValue || length < -0) {
+  // of the new cons string is too large.
+  if (length > String::kMaxLength || length < 0) {
     Top::context()->mark_out_of_memory();
     return Failure::OutOfMemoryException();
   }
 
   // If the resulting string is small make a flat string.
   if (length < String::kMinNonFlatLength) {
     ASSERT(first->IsFlat());
     ASSERT(second->IsFlat());
     if (is_ascii) {
       Object* result = AllocateRawAsciiString(length);
@@ skipping 2193 matching lines @@
   for (int i = 0; i < kNumberOfCaches; i++) {
     if (caches_[i] != NULL) {
       delete caches_[i];
       caches_[i] = NULL;
     }
   }
 }
 
 
 } }  // namespace v8::internal