Implements checks for 53-bit overflow for x64.

runtime/vm/object.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/object.h"
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/cpu.h"
@@ skipping 10477 matching lines @@
 }
 
 
 int Integer::CompareWith(const Integer& other) const {
   UNIMPLEMENTED();
   return 0;
 }
 
 
 static void CheckFiftyThreeBitOverflow(const Integer &i) {
-  if (i.IsSmi()) return;
   // Always overflow if the value doesn't fit into an int64_t.
   int64_t value = 1ULL << 63;
-  if (i.IsMint()) {
+  if (i.IsSmi()) {
+    value = i.AsInt64Value();
+  } else if (i.IsMint()) {
     Mint& mint = Mint::Handle();
     mint ^= i.raw();
     value = mint.value();
   } else {
     ASSERT(i.IsBigint());
     Bigint& big_value = Bigint::Handle();
     big_value ^= i.raw();
     if (BigintOperations::FitsIntoInt64(big_value)) {
       value = BigintOperations::ToInt64(big_value);
     }
@@ skipping 2860 matching lines @@
                                     space);
   return reinterpret_cast<RawWeakProperty*>(raw);
 }
 
 
 const char* WeakProperty::ToCString() const {
   return "_WeakProperty";
 }
 
 }  // namespace dart