Serendipitously arrange the tags so that String.length() becomes a branch-fre...

src/objects.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 3950 matching lines @@
 
 uint32_t StringHasher::GetHashField() {
   ASSERT(is_valid());
   if (length_ <= String::kMaxShortStringSize) {
     uint32_t payload;
     if (is_array_index()) {
       payload = v8::internal::HashField(array_index(), true);
     } else {
       payload = v8::internal::HashField(GetHash(), false);
     }
-    return (payload & 0x00FFFFFF) | (length_ << String::kShortLengthShift);
+    return (payload & ((1 << String::kShortLengthShift) - 1)) |
+           (length_ << String::kShortLengthShift);
   } else if (length_ <= String::kMaxMediumStringSize) {
     uint32_t payload = v8::internal::HashField(GetHash(), false);
-    return (payload & 0x0000FFFF) | (length_ << String::kMediumLengthShift);
+    return (payload & ((1 << String::kMediumLengthShift) - 1)) |
+           (length_ << String::kMediumLengthShift);
   } else {
     return v8::internal::HashField(length_, false);
   }
 }
 
 
 uint32_t String::ComputeLengthAndHashField(unibrow::CharacterStream* buffer,
                                            int length) {
   StringHasher hasher(length);
 
@@ skipping 2737 matching lines @@
   // No break point.
   if (break_point_objects()->IsUndefined()) return 0;
   // Single beak point.
   if (!break_point_objects()->IsFixedArray()) return 1;
   // Multiple break points.
   return FixedArray::cast(break_point_objects())->length();
 }
 
 
 } }  // namespace v8::internal