Don't create a Bigint object first for every integer while parsing the sources, instead first check…

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 "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/bigint_operations.h"
 #include "vm/bootstrap.h"
@@ skipping 7664 matching lines @@
 
 
 const char* Integer::ToCString() const {
   // Integer is an interface. No instances of Integer should exist.
   UNREACHABLE();
   return "Integer";
 }
 
 
 RawInteger* Integer::New(const String& str, Heap::Space space) {
-  // TODO(iposva): If returning a big integer it will not necessarily be in the
-  // requested space.
-  const Bigint& big = Bigint::Handle(Bigint::New(str));
-  if (BigintOperations::FitsIntoSmi(big)) {
-    return BigintOperations::ToSmi(big);
-  } else if (BigintOperations::FitsIntoMint(big)) {
-    return Mint::New(BigintOperations::ToMint(big), space);
-  } else {
+  // We are not supposed to have integers represented as two byte or
+  // four byte strings.
+  ASSERT(str.IsOneByteString());
+  const OneByteString& onestr = OneByteString::Cast(str);
+  int64_t value;
+  if (!OS::StringToInteger(onestr.ToCString(), &value)) {
+    const Bigint& big = Bigint::Handle(Bigint::New(onestr, space));
+    ASSERT(!BigintOperations::FitsIntoSmi(big));
+    ASSERT(!BigintOperations::FitsIntoMint(big));
     return big.raw();
   }
+  return Integer::New(value, space);
 }
 
 
 RawInteger* Integer::New(int64_t value, Heap::Space space) {
   if ((value <= Smi::kMaxValue) && (value >= Smi::kMinValue)) {
     return Smi::New(value);
   }
   return Mint::New(value, space);
 }
 
@@ skipping 2950 matching lines @@
   const String& str = String::Handle(pattern());
   const char* format = "JSRegExp: pattern=%s flags=%s";
   intptr_t len = OS::SNPrint(NULL, 0, format, str.ToCString(), Flags());
   char* chars = reinterpret_cast<char*>(
       Isolate::Current()->current_zone()->Allocate(len + 1));
   OS::SNPrint(chars, (len + 1), format, str.ToCString(), Flags());
   return chars;
 }
 
 }  // namespace dart