Use kSmiBits rather than #ifdef to define hash map constant.

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 19657 matching lines @@
 typedef EnumIndexHashMap<DefaultHashTraits> EnumIndexDefaultMap;
 
 
 RawLinkedHashMap* LinkedHashMap::NewDefault(Heap::Space space) {
   // Keep this in sync with Dart implementation (lib/compact_hash.dart).
   static const intptr_t kInitialIndexBits = 3;
   static const intptr_t kInitialIndexSize = 1 << (kInitialIndexBits + 1);
   const Array& data = Array::Handle(Array::New(kInitialIndexSize, space));
   const TypedData& index = TypedData::Handle(TypedData::New(
       kTypedDataUint32ArrayCid, kInitialIndexSize, space));
+  // On 32-bit, the top bits are wasted to avoid Mint allocation.
+  static const intptr_t kAvailableBits = (kSmiBits >= 32) ? 32 : kSmiBits;
   static const intptr_t kInitialHashMask =
-#if defined(ARCH_IS_64_BIT)
-      (1 << (32 - kInitialIndexBits)) - 1;
-#else
-      (1 << (30 - kInitialIndexBits)) - 1;
-#endif
+      (1 << (kAvailableBits - kInitialIndexBits)) - 1;
   return LinkedHashMap::New(data, index, kInitialHashMask, 0, 0, space);
 }
 
 
 RawLinkedHashMap* LinkedHashMap::New(const Array& data,
                                      const TypedData& index,
                                      intptr_t hash_mask,
                                      intptr_t used_data,
                                      intptr_t deleted_keys,
                                      Heap::Space space) {
@@ skipping 1126 matching lines @@
   return tag_label.ToCString();
 }
 
 
 void UserTag::PrintJSONImpl(JSONStream* stream, bool ref) const {
   Instance::PrintJSONImpl(stream, ref);
 }
 
 
 }  // namespace dart