Imported v8 version 3.7.3 from https://github.com/v8/v8.git

Change-Id: I152648081e46f599c2bb88eaaf67034fa5daac3a

1 files changed, 947 insertions, 0 deletions

diff --git a/src/3rdparty/v8/src/utils.h b/src/3rdparty/v8/src/utils.h
new file mode 100644
index 0000000..2e6cfbd
--- /dev/null
+++ b/src/3rdparty/v8/src/utils.h
@@ -0,0 +1,947 @@
+// Copyright 2011 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
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef V8_UTILS_H_
+#define V8_UTILS_H_
+
+#include <stdlib.h>
+#include <string.h>
+#include <climits>
+
+#include "globals.h"
+#include "checks.h"
+#include "allocation.h"
+
+namespace v8 {
+namespace internal {
+
+// ----------------------------------------------------------------------------
+// General helper functions
+
+#define IS_POWER_OF_TWO(x) (((x) & ((x) - 1)) == 0)
+
+// Returns true iff x is a power of 2 (or zero). Cannot be used with the
+// maximally negative value of the type T (the -1 overflows).
+template <typename T>
+static inline bool IsPowerOf2(T x) {
+  return IS_POWER_OF_TWO(x);
+}
+
+
+// X must be a power of 2.  Returns the number of trailing zeros.
+static inline int WhichPowerOf2(uint32_t x) {
+  ASSERT(IsPowerOf2(x));
+  ASSERT(x != 0);
+  int bits = 0;
+#ifdef DEBUG
+  int original_x = x;
+#endif
+  if (x >= 0x10000) {
+    bits += 16;
+    x >>= 16;
+  }
+  if (x >= 0x100) {
+    bits += 8;
+    x >>= 8;
+  }
+  if (x >= 0x10) {
+    bits += 4;
+    x >>= 4;
+  }
+  switch (x) {
+    default: UNREACHABLE();
+    case 8: bits++;  // Fall through.
+    case 4: bits++;  // Fall through.
+    case 2: bits++;  // Fall through.
+    case 1: break;
+  }
+  ASSERT_EQ(1 << bits, original_x);
+  return bits;
+  return 0;
+}
+
+
+// The C++ standard leaves the semantics of '>>' undefined for
+// negative signed operands. Most implementations do the right thing,
+// though.
+static inline int ArithmeticShiftRight(int x, int s) {
+  return x >> s;
+}
+
+
+// Compute the 0-relative offset of some absolute value x of type T.
+// This allows conversion of Addresses and integral types into
+// 0-relative int offsets.
+template <typename T>
+static inline intptr_t OffsetFrom(T x) {
+  return x - static_cast<T>(0);
+}
+
+
+// Compute the absolute value of type T for some 0-relative offset x.
+// This allows conversion of 0-relative int offsets into Addresses and
+// integral types.
+template <typename T>
+static inline T AddressFrom(intptr_t x) {
+  return static_cast<T>(static_cast<T>(0) + x);
+}
+
+
+// Return the largest multiple of m which is <= x.
+template <typename T>
+static inline T RoundDown(T x, intptr_t m) {
+  ASSERT(IsPowerOf2(m));
+  return AddressFrom<T>(OffsetFrom(x) & -m);
+}
+
+
+// Return the smallest multiple of m which is >= x.
+template <typename T>
+static inline T RoundUp(T x, intptr_t m) {
+  return RoundDown<T>(static_cast<T>(x + m - 1), m);
+}
+
+
+template <typename T>
+static int Compare(const T& a, const T& b) {
+  if (a == b)
+    return 0;
+  else if (a < b)
+    return -1;
+  else
+    return 1;
+}
+
+
+template <typename T>
+static int PointerValueCompare(const T* a, const T* b) {
+  return Compare<T>(*a, *b);
+}
+
+
+// Compare function to compare the object pointer value of two
+// handlified objects. The handles are passed as pointers to the
+// handles.
+template<typename T> class Handle;  // Forward declaration.
+template <typename T>
+static int HandleObjectPointerCompare(const Handle<T>* a, const Handle<T>* b) {
+  return Compare<T*>(*(*a), *(*b));
+}
+
+
+// Returns the smallest power of two which is >= x. If you pass in a
+// number that is already a power of two, it is returned as is.
+// Implementation is from "Hacker's Delight" by Henry S. Warren, Jr.,
+// figure 3-3, page 48, where the function is called clp2.
+static inline uint32_t RoundUpToPowerOf2(uint32_t x) {
+  ASSERT(x <= 0x80000000u);
+  x = x - 1;
+  x = x | (x >> 1);
+  x = x | (x >> 2);
+  x = x | (x >> 4);
+  x = x | (x >> 8);
+  x = x | (x >> 16);
+  return x + 1;
+}
+
+
+static inline uint32_t RoundDownToPowerOf2(uint32_t x) {
+  uint32_t rounded_up = RoundUpToPowerOf2(x);
+  if (rounded_up > x) return rounded_up >> 1;
+  return rounded_up;
+}
+
+
+template <typename T, typename U>
+static inline bool IsAligned(T value, U alignment) {
+  return (value & (alignment - 1)) == 0;
+}
+
+
+// Returns true if (addr + offset) is aligned.
+static inline bool IsAddressAligned(Address addr,
+                                    intptr_t alignment,
+                                    int offset = 0) {
+  intptr_t offs = OffsetFrom(addr + offset);
+  return IsAligned(offs, alignment);
+}
+
+
+// Returns the maximum of the two parameters.
+template <typename T>
+static T Max(T a, T b) {
+  return a < b ? b : a;
+}
+
+
+// Returns the minimum of the two parameters.
+template <typename T>
+static T Min(T a, T b) {
+  return a < b ? a : b;
+}
+
+
+inline int StrLength(const char* string) {
+  size_t length = strlen(string);
+  ASSERT(length == static_cast<size_t>(static_cast<int>(length)));
+  return static_cast<int>(length);
+}
+
+
+// ----------------------------------------------------------------------------
+// BitField is a help template for encoding and decode bitfield with
+// unsigned content.
+template<class T, int shift, int size>
+class BitField {
+ public:
+  // A uint32_t mask of bit field.  To use all bits of a uint32 in a
+  // bitfield without compiler warnings we have to compute 2^32 without
+  // using a shift count of 32.
+  static const uint32_t kMask = ((1U << shift) << size) - (1U << shift);
+
+  // Value for the field with all bits set.
+  static const T kMax = static_cast<T>((1U << size) - 1);
+
+  // Tells whether the provided value fits into the bit field.
+  static bool is_valid(T value) {
+    return (static_cast<uint32_t>(value) & ~static_cast<uint32_t>(kMax)) == 0;
+  }
+
+  // Returns a uint32_t with the bit field value encoded.
+  static uint32_t encode(T value) {
+    ASSERT(is_valid(value));
+    return static_cast<uint32_t>(value) << shift;
+  }
+
+  // Returns a uint32_t with the bit field value updated.
+  static uint32_t update(uint32_t previous, T value) {
+    return (previous & ~kMask) | encode(value);
+  }
+
+  // Extracts the bit field from the value.
+  static T decode(uint32_t value) {
+    return static_cast<T>((value & kMask) >> shift);
+  }
+};
+
+
+// ----------------------------------------------------------------------------
+// Hash function.
+
+// Thomas Wang, Integer Hash Functions.
+// http://www.concentric.net/~Ttwang/tech/inthash.htm
+static inline uint32_t ComputeIntegerHash(uint32_t key) {
+  uint32_t hash = key;
+  hash = ~hash + (hash << 15);  // hash = (hash << 15) - hash - 1;
+  hash = hash ^ (hash >> 12);
+  hash = hash + (hash << 2);
+  hash = hash ^ (hash >> 4);
+  hash = hash * 2057;  // hash = (hash + (hash << 3)) + (hash << 11);
+  hash = hash ^ (hash >> 16);
+  return hash;
+}
+
+
+static inline uint32_t ComputeLongHash(uint64_t key) {
+  uint64_t hash = key;
+  hash = ~hash + (hash << 18);  // hash = (hash << 18) - hash - 1;
+  hash = hash ^ (hash >> 31);
+  hash = hash * 21;  // hash = (hash + (hash << 2)) + (hash << 4);
+  hash = hash ^ (hash >> 11);
+  hash = hash + (hash << 6);
+  hash = hash ^ (hash >> 22);
+  return (uint32_t) hash;
+}
+
+
+static inline uint32_t ComputePointerHash(void* ptr) {
+  return ComputeIntegerHash(
+      static_cast<uint32_t>(reinterpret_cast<intptr_t>(ptr)));
+}
+
+
+// ----------------------------------------------------------------------------
+// Miscellaneous
+
+// A static resource holds a static instance that can be reserved in
+// a local scope using an instance of Access.  Attempts to re-reserve
+// the instance will cause an error.
+template <typename T>
+class StaticResource {
+ public:
+  StaticResource() : is_reserved_(false)  {}
+
+ private:
+  template <typename S> friend class Access;
+  T instance_;
+  bool is_reserved_;
+};
+
+
+// Locally scoped access to a static resource.
+template <typename T>
+class Access {
+ public:
+  explicit Access(StaticResource<T>* resource)
+    : resource_(resource)
+    , instance_(&resource->instance_) {
+    ASSERT(!resource->is_reserved_);
+    resource->is_reserved_ = true;
+  }
+
+  ~Access() {
+    resource_->is_reserved_ = false;
+    resource_ = NULL;
+    instance_ = NULL;
+  }
+
+  T* value()  { return instance_; }
+  T* operator -> ()  { return instance_; }
+
+ private:
+  StaticResource<T>* resource_;
+  T* instance_;
+};
+
+
+template <typename T>
+class Vector {
+ public:
+  Vector() : start_(NULL), length_(0) {}
+  Vector(T* data, int length) : start_(data), length_(length) {
+    ASSERT(length == 0 || (length > 0 && data != NULL));
+  }
+
+  static Vector<T> New(int length) {
+    return Vector<T>(NewArray<T>(length), length);
+  }
+
+  // Returns a vector using the same backing storage as this one,
+  // spanning from and including 'from', to but not including 'to'.
+  Vector<T> SubVector(int from, int to) {
+    ASSERT(to <= length_);
+    ASSERT(from < to);
+    ASSERT(0 <= from);
+    return Vector<T>(start() + from, to - from);
+  }
+
+  // Returns the length of the vector.
+  int length() const { return length_; }
+
+  // Returns whether or not the vector is empty.
+  bool is_empty() const { return length_ == 0; }
+
+  // Returns the pointer to the start of the data in the vector.
+  T* start() const { return start_; }
+
+  // Access individual vector elements - checks bounds in debug mode.
+  T& operator[](int index) const {
+    ASSERT(0 <= index && index < length_);
+    return start_[index];
+  }
+
+  const T& at(int index) const { return operator[](index); }
+
+  T& first() { return start_[0]; }
+
+  T& last() { return start_[length_ - 1]; }
+
+  // Returns a clone of this vector with a new backing store.
+  Vector<T> Clone() const {
+    T* result = NewArray<T>(length_);
+    for (int i = 0; i < length_; i++) result[i] = start_[i];
+    return Vector<T>(result, length_);
+  }
+
+  void Sort(int (*cmp)(const T*, const T*)) {
+    typedef int (*RawComparer)(const void*, const void*);
+    qsort(start(),
+          length(),
+          sizeof(T),
+          reinterpret_cast<RawComparer>(cmp));
+  }
+
+  void Sort() {
+    Sort(PointerValueCompare<T>);
+  }
+
+  void Truncate(int length) {
+    ASSERT(length <= length_);
+    length_ = length;
+  }
+
+  // Releases the array underlying this vector. Once disposed the
+  // vector is empty.
+  void Dispose() {
+    DeleteArray(start_);
+    start_ = NULL;
+    length_ = 0;
+  }
+
+  inline Vector<T> operator+(int offset) {
+    ASSERT(offset < length_);
+    return Vector<T>(start_ + offset, length_ - offset);
+  }
+
+  // Factory method for creating empty vectors.
+  static Vector<T> empty() { return Vector<T>(NULL, 0); }
+
+  template<typename S>
+  static Vector<T> cast(Vector<S> input) {
+    return Vector<T>(reinterpret_cast<T*>(input.start()),
+                     input.length() * sizeof(S) / sizeof(T));
+  }
+
+ protected:
+  void set_start(T* start) { start_ = start; }
+
+ private:
+  T* start_;
+  int length_;
+};
+
+
+// A pointer that can only be set once and doesn't allow NULL values.
+template<typename T>
+class SetOncePointer {
+ public:
+  SetOncePointer() : pointer_(NULL) { }
+
+  bool is_set() const { return pointer_ != NULL; }
+
+  T* get() const {
+    ASSERT(pointer_ != NULL);
+    return pointer_;
+  }
+
+  void set(T* value) {
+    ASSERT(pointer_ == NULL && value != NULL);
+    pointer_ = value;
+  }
+
+ private:
+  T* pointer_;
+};
+
+
+template <typename T, int kSize>
+class EmbeddedVector : public Vector<T> {
+ public:
+  EmbeddedVector() : Vector<T>(buffer_, kSize) { }
+
+  explicit EmbeddedVector(T initial_value) : Vector<T>(buffer_, kSize) {
+    for (int i = 0; i < kSize; ++i) {
+      buffer_[i] = initial_value;
+    }
+  }
+
+  // When copying, make underlying Vector to reference our buffer.
+  EmbeddedVector(const EmbeddedVector& rhs)
+      : Vector<T>(rhs) {
+    memcpy(buffer_, rhs.buffer_, sizeof(T) * kSize);
+    set_start(buffer_);
+  }
+
+  EmbeddedVector& operator=(const EmbeddedVector& rhs) {
+    if (this == &rhs) return *this;
+    Vector<T>::operator=(rhs);
+    memcpy(buffer_, rhs.buffer_, sizeof(T) * kSize);
+    this->set_start(buffer_);
+    return *this;
+  }
+
+ private:
+  T buffer_[kSize];
+};
+
+
+template <typename T>
+class ScopedVector : public Vector<T> {
+ public:
+  explicit ScopedVector(int length) : Vector<T>(NewArray<T>(length), length) { }
+  ~ScopedVector() {
+    DeleteArray(this->start());
+  }
+
+ private:
+  DISALLOW_IMPLICIT_CONSTRUCTORS(ScopedVector);
+};
+
+
+inline Vector<const char> CStrVector(const char* data) {
+  return Vector<const char>(data, StrLength(data));
+}
+
+inline Vector<char> MutableCStrVector(char* data) {
+  return Vector<char>(data, StrLength(data));
+}
+
+inline Vector<char> MutableCStrVector(char* data, int max) {
+  int length = StrLength(data);
+  return Vector<char>(data, (length < max) ? length : max);
+}
+
+
+/*
+ * A class that collects values into a backing store.
+ * Specialized versions of the class can allow access to the backing store
+ * in different ways.
+ * There is no guarantee that the backing store is contiguous (and, as a
+ * consequence, no guarantees that consecutively added elements are adjacent
+ * in memory). The collector may move elements unless it has guaranteed not
+ * to.
+ */
+template <typename T, int growth_factor = 2, int max_growth = 1 * MB>
+class Collector {
+ public:
+  explicit Collector(int initial_capacity = kMinCapacity)
+      : index_(0), size_(0) {
+    current_chunk_ = Vector<T>::New(initial_capacity);
+  }
+
+  virtual ~Collector() {
+    // Free backing store (in reverse allocation order).
+    current_chunk_.Dispose();
+    for (int i = chunks_.length() - 1; i >= 0; i--) {
+      chunks_.at(i).Dispose();
+    }
+  }
+
+  // Add a single element.
+  inline void Add(T value) {
+    if (index_ >= current_chunk_.length()) {
+      Grow(1);
+    }
+    current_chunk_[index_] = value;
+    index_++;
+    size_++;
+  }
+
+  // Add a block of contiguous elements and return a Vector backed by the
+  // memory area.
+  // A basic Collector will keep this vector valid as long as the Collector
+  // is alive.
+  inline Vector<T> AddBlock(int size, T initial_value) {
+    ASSERT(size > 0);
+    if (size > current_chunk_.length() - index_) {
+      Grow(size);
+    }
+    T* position = current_chunk_.start() + index_;
+    index_ += size;
+    size_ += size;
+    for (int i = 0; i < size; i++) {
+      position[i] = initial_value;
+    }
+    return Vector<T>(position, size);
+  }
+
+
+  // Add a contiguous block of elements and return a vector backed
+  // by the added block.
+  // A basic Collector will keep this vector valid as long as the Collector
+  // is alive.
+  inline Vector<T> AddBlock(Vector<const T> source) {
+    if (source.length() > current_chunk_.length() - index_) {
+      Grow(source.length());
+    }
+    T* position = current_chunk_.start() + index_;
+    index_ += source.length();
+    size_ += source.length();
+    for (int i = 0; i < source.length(); i++) {
+      position[i] = source[i];
+    }
+    return Vector<T>(position, source.length());
+  }
+
+
+  // Write the contents of the collector into the provided vector.
+  void WriteTo(Vector<T> destination) {
+    ASSERT(size_ <= destination.length());
+    int position = 0;
+    for (int i = 0; i < chunks_.length(); i++) {
+      Vector<T> chunk = chunks_.at(i);
+      for (int j = 0; j < chunk.length(); j++) {
+        destination[position] = chunk[j];
+        position++;
+      }
+    }
+    for (int i = 0; i < index_; i++) {
+      destination[position] = current_chunk_[i];
+      position++;
+    }
+  }
+
+  // Allocate a single contiguous vector, copy all the collected
+  // elements to the vector, and return it.
+  // The caller is responsible for freeing the memory of the returned
+  // vector (e.g., using Vector::Dispose).
+  Vector<T> ToVector() {
+    Vector<T> new_store = Vector<T>::New(size_);
+    WriteTo(new_store);
+    return new_store;
+  }
+
+  // Resets the collector to be empty.
+  virtual void Reset();
+
+  // Total number of elements added to collector so far.
+  inline int size() { return size_; }
+
+ protected:
+  static const int kMinCapacity = 16;
+  List<Vector<T> > chunks_;
+  Vector<T> current_chunk_;  // Block of memory currently being written into.
+  int index_;  // Current index in current chunk.
+  int size_;  // Total number of elements in collector.
+
+  // Creates a new current chunk, and stores the old chunk in the chunks_ list.
+  void Grow(int min_capacity) {
+    ASSERT(growth_factor > 1);
+    int new_capacity;
+    int current_length = current_chunk_.length();
+    if (current_length < kMinCapacity) {
+      // The collector started out as empty.
+      new_capacity = min_capacity * growth_factor;
+      if (new_capacity < kMinCapacity) new_capacity = kMinCapacity;
+    } else {
+      int growth = current_length * (growth_factor - 1);
+      if (growth > max_growth) {
+        growth = max_growth;
+      }
+      new_capacity = current_length + growth;
+      if (new_capacity < min_capacity) {
+        new_capacity = min_capacity + growth;
+      }
+    }
+    NewChunk(new_capacity);
+    ASSERT(index_ + min_capacity <= current_chunk_.length());
+  }
+
+  // Before replacing the current chunk, give a subclass the option to move
+  // some of the current data into the new chunk. The function may update
+  // the current index_ value to represent data no longer in the current chunk.
+  // Returns the initial index of the new chunk (after copied data).
+  virtual void NewChunk(int new_capacity)  {
+    Vector<T> new_chunk = Vector<T>::New(new_capacity);
+    if (index_ > 0) {
+      chunks_.Add(current_chunk_.SubVector(0, index_));
+    } else {
+      current_chunk_.Dispose();
+    }
+    current_chunk_ = new_chunk;
+    index_ = 0;
+  }
+};
+
+
+/*
+ * A collector that allows sequences of values to be guaranteed to
+ * stay consecutive.
+ * If the backing store grows while a sequence is active, the current
+ * sequence might be moved, but after the sequence is ended, it will
+ * not move again.
+ * NOTICE: Blocks allocated using Collector::AddBlock(int) can move
+ * as well, if inside an active sequence where another element is added.
+ */
+template <typename T, int growth_factor = 2, int max_growth = 1 * MB>
+class SequenceCollector : public Collector<T, growth_factor, max_growth> {
+ public:
+  explicit SequenceCollector(int initial_capacity)
+      : Collector<T, growth_factor, max_growth>(initial_capacity),
+        sequence_start_(kNoSequence) { }
+
+  virtual ~SequenceCollector() {}
+
+  void StartSequence() {
+    ASSERT(sequence_start_ == kNoSequence);
+    sequence_start_ = this->index_;
+  }
+
+  Vector<T> EndSequence() {
+    ASSERT(sequence_start_ != kNoSequence);
+    int sequence_start = sequence_start_;
+    sequence_start_ = kNoSequence;
+    if (sequence_start == this->index_) return Vector<T>();
+    return this->current_chunk_.SubVector(sequence_start, this->index_);
+  }
+
+  // Drops the currently added sequence, and all collected elements in it.
+  void DropSequence() {
+    ASSERT(sequence_start_ != kNoSequence);
+    int sequence_length = this->index_ - sequence_start_;
+    this->index_ = sequence_start_;
+    this->size_ -= sequence_length;
+    sequence_start_ = kNoSequence;
+  }
+
+  virtual void Reset() {
+    sequence_start_ = kNoSequence;
+    this->Collector<T, growth_factor, max_growth>::Reset();
+  }
+
+ private:
+  static const int kNoSequence = -1;
+  int sequence_start_;
+
+  // Move the currently active sequence to the new chunk.
+  virtual void NewChunk(int new_capacity) {
+    if (sequence_start_ == kNoSequence) {
+      // Fall back on default behavior if no sequence has been started.
+      this->Collector<T, growth_factor, max_growth>::NewChunk(new_capacity);
+      return;
+    }
+    int sequence_length = this->index_ - sequence_start_;
+    Vector<T> new_chunk = Vector<T>::New(sequence_length + new_capacity);
+    ASSERT(sequence_length < new_chunk.length());
+    for (int i = 0; i < sequence_length; i++) {
+      new_chunk[i] = this->current_chunk_[sequence_start_ + i];
+    }
+    if (sequence_start_ > 0) {
+      this->chunks_.Add(this->current_chunk_.SubVector(0, sequence_start_));
+    } else {
+      this->current_chunk_.Dispose();
+    }
+    this->current_chunk_ = new_chunk;
+    this->index_ = sequence_length;
+    sequence_start_ = 0;
+  }
+};
+
+
+// Compare ASCII/16bit chars to ASCII/16bit chars.
+template <typename lchar, typename rchar>
+static inline int CompareChars(const lchar* lhs, const rchar* rhs, int chars) {
+  const lchar* limit = lhs + chars;
+#ifdef V8_HOST_CAN_READ_UNALIGNED
+  if (sizeof(*lhs) == sizeof(*rhs)) {
+    // Number of characters in a uintptr_t.
+    static const int kStepSize = sizeof(uintptr_t) / sizeof(*lhs);  // NOLINT
+    while (lhs <= limit - kStepSize) {
+      if (*reinterpret_cast<const uintptr_t*>(lhs) !=
+          *reinterpret_cast<const uintptr_t*>(rhs)) {
+        break;
+      }
+      lhs += kStepSize;
+      rhs += kStepSize;
+    }
+  }
+#endif
+  while (lhs < limit) {
+    int r = static_cast<int>(*lhs) - static_cast<int>(*rhs);
+    if (r != 0) return r;
+    ++lhs;
+    ++rhs;
+  }
+  return 0;
+}
+
+
+// Calculate 10^exponent.
+static inline int TenToThe(int exponent) {
+  ASSERT(exponent <= 9);
+  ASSERT(exponent >= 1);
+  int answer = 10;
+  for (int i = 1; i < exponent; i++) answer *= 10;
+  return answer;
+}
+
+
+// The type-based aliasing rule allows the compiler to assume that pointers of
+// different types (for some definition of different) never alias each other.
+// Thus the following code does not work:
+//
+// float f = foo();
+// int fbits = *(int*)(&f);
+//
+// The compiler 'knows' that the int pointer can't refer to f since the types
+// don't match, so the compiler may cache f in a register, leaving random data
+// in fbits.  Using C++ style casts makes no difference, however a pointer to
+// char data is assumed to alias any other pointer.  This is the 'memcpy
+// exception'.
+//
+// Bit_cast uses the memcpy exception to move the bits from a variable of one
+// type of a variable of another type.  Of course the end result is likely to
+// be implementation dependent.  Most compilers (gcc-4.2 and MSVC 2005)
+// will completely optimize BitCast away.
+//
+// There is an additional use for BitCast.
+// Recent gccs will warn when they see casts that may result in breakage due to
+// the type-based aliasing rule.  If you have checked that there is no breakage
+// you can use BitCast to cast one pointer type to another.  This confuses gcc
+// enough that it can no longer see that you have cast one pointer type to
+// another thus avoiding the warning.
+
+// We need different implementations of BitCast for pointer and non-pointer
+// values. We use partial specialization of auxiliary struct to work around
+// issues with template functions overloading.
+template <class Dest, class Source>
+struct BitCastHelper {
+  STATIC_ASSERT(sizeof(Dest) == sizeof(Source));
+
+  INLINE(static Dest cast(const Source& source)) {
+    Dest dest;
+    memcpy(&dest, &source, sizeof(dest));
+    return dest;
+  }
+};
+
+template <class Dest, class Source>
+struct BitCastHelper<Dest, Source*> {
+  INLINE(static Dest cast(Source* source)) {
+    return BitCastHelper<Dest, uintptr_t>::
+        cast(reinterpret_cast<uintptr_t>(source));
+  }
+};
+
+template <class Dest, class Source>
+INLINE(Dest BitCast(const Source& source));
+
+template <class Dest, class Source>
+inline Dest BitCast(const Source& source) {
+  return BitCastHelper<Dest, Source>::cast(source);
+}
+
+
+template<typename ElementType, int NumElements>
+class EmbeddedContainer {
+ public:
+  EmbeddedContainer() : elems_() { }
+
+  int length() { return NumElements; }
+  ElementType& operator[](int i) {
+    ASSERT(i < length());
+    return elems_[i];
+  }
+
+ private:
+  ElementType elems_[NumElements];
+};
+
+
+template<typename ElementType>
+class EmbeddedContainer<ElementType, 0> {
+ public:
+  int length() { return 0; }
+  ElementType& operator[](int i) {
+    UNREACHABLE();
+    static ElementType t = 0;
+    return t;
+  }
+};
+
+
+// Helper class for building result strings in a character buffer. The
+// purpose of the class is to use safe operations that checks the
+// buffer bounds on all operations in debug mode.
+// This simple base class does not allow formatted output.
+class SimpleStringBuilder {
+ public:
+  // Create a string builder with a buffer of the given size. The
+  // buffer is allocated through NewArray<char> and must be
+  // deallocated by the caller of Finalize().
+  explicit SimpleStringBuilder(int size);
+
+  SimpleStringBuilder(char* buffer, int size)
+      : buffer_(buffer, size), position_(0) { }
+
+  ~SimpleStringBuilder() { if (!is_finalized()) Finalize(); }
+
+  int size() const { return buffer_.length(); }
+
+  // Get the current position in the builder.
+  int position() const {
+    ASSERT(!is_finalized());
+    return position_;
+  }
+
+  // Reset the position.
+  void Reset() { position_ = 0; }
+
+  // Add a single character to the builder. It is not allowed to add
+  // 0-characters; use the Finalize() method to terminate the string
+  // instead.
+  void AddCharacter(char c) {
+    ASSERT(c != '\0');
+    ASSERT(!is_finalized() && position_ < buffer_.length());
+    buffer_[position_++] = c;
+  }
+
+  // Add an entire string to the builder. Uses strlen() internally to
+  // compute the length of the input string.
+  void AddString(const char* s);
+
+  // Add the first 'n' characters of the given string 's' to the
+  // builder. The input string must have enough characters.
+  void AddSubstring(const char* s, int n);
+
+  // Add character padding to the builder. If count is non-positive,
+  // nothing is added to the builder.
+  void AddPadding(char c, int count);
+
+  // Add the decimal representation of the value.
+  void AddDecimalInteger(int value);
+
+  // Finalize the string by 0-terminating it and returning the buffer.
+  char* Finalize();
+
+ protected:
+  Vector<char> buffer_;
+  int position_;
+
+  bool is_finalized() const { return position_ < 0; }
+
+ private:
+  DISALLOW_IMPLICIT_CONSTRUCTORS(SimpleStringBuilder);
+};
+
+
+// A poor man's version of STL's bitset: A bit set of enums E (without explicit
+// values), fitting into an integral type T.
+template <class E, class T = int>
+class EnumSet {
+ public:
+  explicit EnumSet(T bits = 0) : bits_(bits) {}
+  bool IsEmpty() const { return bits_ == 0; }
+  bool Contains(E element) const { return (bits_ & Mask(element)) != 0; }
+  void Add(E element) { bits_ |= Mask(element); }
+  void Remove(E element) { bits_ &= ~Mask(element); }
+  T ToIntegral() const { return bits_; }
+
+ private:
+  T Mask(E element) const {
+    // The strange typing in ASSERT is necessary to avoid stupid warnings, see:
+    // http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43680
+    ASSERT(element < static_cast<int>(sizeof(T) * CHAR_BIT));
+    return 1 << element;
+  }
+
+  T bits_;
+};
+
+} }  // namespace v8::internal
+
+#endif  // V8_UTILS_H_