Move Hydrogen and Lithium to src/crankshaft/

src/unique.h

-// Copyright 2013 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef V8_UNIQUE_H_
-#define V8_UNIQUE_H_
-
-#include <ostream>  // NOLINT(readability/streams)
-
-#include "src/base/functional.h"
-#include "src/handles.h"
-#include "src/utils.h"
-#include "src/zone.h"
-
-namespace v8 {
-namespace internal {
-
-
-template <typename T>
-class UniqueSet;
-
-
-// Represents a handle to an object on the heap, but with the additional
-// ability of checking for equality and hashing without accessing the heap.
-//
-// Creating a Unique<T> requires first dereferencing the handle to obtain
-// the address of the object, which is used as the hashcode and the basis for
-// comparison. The object can be moved later by the GC, but comparison
-// and hashing use the old address of the object, without dereferencing it.
-//
-// Careful! Comparison of two Uniques is only correct if both were created
-// in the same "era" of GC or if at least one is a non-movable object.
-template <typename T>
-class Unique final {
- public:
-  Unique<T>() : raw_address_(NULL) {}
-
-  // TODO(titzer): make private and introduce a uniqueness scope.
-  explicit Unique(Handle<T> handle) {
-    if (handle.is_null()) {
-      raw_address_ = NULL;
-    } else {
-      // This is a best-effort check to prevent comparing Unique<T>'s created
-      // in different GC eras; we require heap allocation to be disallowed at
-      // creation time.
-      // NOTE: we currently consider maps to be non-movable, so no special
-      // assurance is required for creating a Unique<Map>.
-      // TODO(titzer): other immortable immovable objects are also fine.
-      DCHECK(!AllowHeapAllocation::IsAllowed() || handle->IsMap());
-      raw_address_ = reinterpret_cast<Address>(*handle);
-      DCHECK_NOT_NULL(raw_address_);  // Non-null should imply non-zero address.
-    }
-    handle_ = handle;
-  }
-
-  // Constructor for handling automatic up casting.
-  // Eg. Unique<JSFunction> can be passed when Unique<Object> is expected.
-  template <class S> Unique(Unique<S> uniq) {
-#ifdef DEBUG
-    T* a = NULL;
-    S* b = NULL;
-    a = b;  // Fake assignment to enforce type checks.
-    USE(a);
-#endif
-    raw_address_ = uniq.raw_address_;
-    handle_ = uniq.handle_;
-  }
-
-  template <typename U>
-  inline bool operator==(const Unique<U>& other) const {
-    DCHECK(IsInitialized() && other.IsInitialized());
-    return raw_address_ == other.raw_address_;
-  }
-
-  template <typename U>
-  inline bool operator!=(const Unique<U>& other) const {
-    DCHECK(IsInitialized() && other.IsInitialized());
-    return raw_address_ != other.raw_address_;
-  }
-
-  friend inline size_t hash_value(Unique<T> const& unique) {
-    DCHECK(unique.IsInitialized());
-    return base::hash<void*>()(unique.raw_address_);
-  }
-
-  inline intptr_t Hashcode() const {
-    DCHECK(IsInitialized());
-    return reinterpret_cast<intptr_t>(raw_address_);
-  }
-
-  inline bool IsNull() const {
-    DCHECK(IsInitialized());
-    return raw_address_ == NULL;
-  }
-
-  inline bool IsKnownGlobal(void* global) const {
-    DCHECK(IsInitialized());
-    return raw_address_ == reinterpret_cast<Address>(global);
-  }
-
-  inline Handle<T> handle() const {
-    return handle_;
-  }
-
-  template <class S> static Unique<T> cast(Unique<S> that) {
-    // Allow fetching location() to unsafe-cast the handle. This is necessary
-    // since we can't concurrently safe-cast. Safe-casting requires looking at
-    // the heap which may be moving concurrently to the compiler thread.
-    AllowHandleDereference allow_deref;
-    return Unique<T>(that.raw_address_,
-                     Handle<T>(reinterpret_cast<T**>(that.handle_.location())));
-  }
-
-  inline bool IsInitialized() const {
-    return raw_address_ != NULL || handle_.is_null();
-  }
-
-  // TODO(titzer): this is a hack to migrate to Unique<T> incrementally.
-  static Unique<T> CreateUninitialized(Handle<T> handle) {
-    return Unique<T>(NULL, handle);
-  }
-
-  static Unique<T> CreateImmovable(Handle<T> handle) {
-    return Unique<T>(reinterpret_cast<Address>(*handle), handle);
-  }
-
- private:
-  Unique(Address raw_address, Handle<T> handle)
-      : raw_address_(raw_address), handle_(handle) {}
-
-  Address raw_address_;
-  Handle<T> handle_;
-
-  friend class UniqueSet<T>;  // Uses internal details for speed.
-  template <class U>
-  friend class Unique;  // For comparing raw_address values.
-};
-
-template <typename T>
-inline std::ostream& operator<<(std::ostream& os, Unique<T> uniq) {
-  return os << Brief(*uniq.handle());
-}
-
-
-template <typename T>
-class UniqueSet final : public ZoneObject {
- public:
-  // Constructor. A new set will be empty.
-  UniqueSet() : size_(0), capacity_(0), array_(NULL) { }
-
-  // Capacity constructor. A new set will be empty.
-  UniqueSet(int capacity, Zone* zone)
-      : size_(0), capacity_(capacity),
-        array_(zone->NewArray<Unique<T> >(capacity)) {
-    DCHECK(capacity <= kMaxCapacity);
-  }
-
-  // Singleton constructor.
-  UniqueSet(Unique<T> uniq, Zone* zone)
-      : size_(1), capacity_(1), array_(zone->NewArray<Unique<T> >(1)) {
-    array_[0] = uniq;
-  }
-
-  // Add a new element to this unique set. Mutates this set. O(|this|).
-  void Add(Unique<T> uniq, Zone* zone) {
-    DCHECK(uniq.IsInitialized());
-    // Keep the set sorted by the {raw_address} of the unique elements.
-    for (int i = 0; i < size_; i++) {
-      if (array_[i] == uniq) return;
-      if (array_[i].raw_address_ > uniq.raw_address_) {
-        // Insert in the middle.
-        Grow(size_ + 1, zone);
-        for (int j = size_ - 1; j >= i; j--) array_[j + 1] = array_[j];
-        array_[i] = uniq;
-        size_++;
-        return;
-      }
-    }
-    // Append the element to the the end.
-    Grow(size_ + 1, zone);
-    array_[size_++] = uniq;
-  }
-
-  // Remove an element from this set. Mutates this set. O(|this|)
-  void Remove(Unique<T> uniq) {
-    for (int i = 0; i < size_; i++) {
-      if (array_[i] == uniq) {
-        while (++i < size_) array_[i - 1] = array_[i];
-        size_--;
-        return;
-      }
-    }
-  }
-
-  // Compare this set against another set. O(|this|).
-  bool Equals(const UniqueSet<T>* that) const {
-    if (that->size_ != this->size_) return false;
-    for (int i = 0; i < this->size_; i++) {
-      if (this->array_[i] != that->array_[i]) return false;
-    }
-    return true;
-  }
-
-  // Check whether this set contains the given element. O(|this|)
-  // TODO(titzer): use binary search for large sets to make this O(log|this|)
-  template <typename U>
-  bool Contains(const Unique<U> elem) const {
-    for (int i = 0; i < this->size_; ++i) {
-      Unique<T> cand = this->array_[i];
-      if (cand.raw_address_ >= elem.raw_address_) {
-        return cand.raw_address_ == elem.raw_address_;
-      }
-    }
-    return false;
-  }
-
-  // Check if this set is a subset of the given set. O(|this| + |that|).
-  bool IsSubset(const UniqueSet<T>* that) const {
-    if (that->size_ < this->size_) return false;
-    int j = 0;
-    for (int i = 0; i < this->size_; i++) {
-      Unique<T> sought = this->array_[i];
-      while (true) {
-        if (sought == that->array_[j++]) break;
-        // Fail whenever there are more elements in {this} than {that}.
-        if ((this->size_ - i) > (that->size_ - j)) return false;
-      }
-    }
-    return true;
-  }
-
-  // Returns a new set representing the intersection of this set and the other.
-  // O(|this| + |that|).
-  UniqueSet<T>* Intersect(const UniqueSet<T>* that, Zone* zone) const {
-    if (that->size_ == 0 || this->size_ == 0) return new(zone) UniqueSet<T>();
-
-    UniqueSet<T>* out = new(zone) UniqueSet<T>(
-        Min(this->size_, that->size_), zone);
-
-    int i = 0, j = 0, k = 0;
-    while (i < this->size_ && j < that->size_) {
-      Unique<T> a = this->array_[i];
-      Unique<T> b = that->array_[j];
-      if (a == b) {
-        out->array_[k++] = a;
-        i++;
-        j++;
-      } else if (a.raw_address_ < b.raw_address_) {
-        i++;
-      } else {
-        j++;
-      }
-    }
-
-    out->size_ = k;
-    return out;
-  }
-
-  // Returns a new set representing the union of this set and the other.
-  // O(|this| + |that|).
-  UniqueSet<T>* Union(const UniqueSet<T>* that, Zone* zone) const {
-    if (that->size_ == 0) return this->Copy(zone);
-    if (this->size_ == 0) return that->Copy(zone);
-
-    UniqueSet<T>* out = new(zone) UniqueSet<T>(
-        this->size_ + that->size_, zone);
-
-    int i = 0, j = 0, k = 0;
-    while (i < this->size_ && j < that->size_) {
-      Unique<T> a = this->array_[i];
-      Unique<T> b = that->array_[j];
-      if (a == b) {
-        out->array_[k++] = a;
-        i++;
-        j++;
-      } else if (a.raw_address_ < b.raw_address_) {
-        out->array_[k++] = a;
-        i++;
-      } else {
-        out->array_[k++] = b;
-        j++;
-      }
-    }
-
-    while (i < this->size_) out->array_[k++] = this->array_[i++];
-    while (j < that->size_) out->array_[k++] = that->array_[j++];
-
-    out->size_ = k;
-    return out;
-  }
-
-  // Returns a new set representing all elements from this set which are not in
-  // that set. O(|this| * |that|).
-  UniqueSet<T>* Subtract(const UniqueSet<T>* that, Zone* zone) const {
-    if (that->size_ == 0) return this->Copy(zone);
-
-    UniqueSet<T>* out = new(zone) UniqueSet<T>(this->size_, zone);
-
-    int i = 0, j = 0;
-    while (i < this->size_) {
-      Unique<T> cand = this->array_[i];
-      if (!that->Contains(cand)) {
-        out->array_[j++] = cand;
-      }
-      i++;
-    }
-
-    out->size_ = j;
-    return out;
-  }
-
-  // Makes an exact copy of this set. O(|this|).
-  UniqueSet<T>* Copy(Zone* zone) const {
-    UniqueSet<T>* copy = new(zone) UniqueSet<T>(this->size_, zone);
-    copy->size_ = this->size_;
-    memcpy(copy->array_, this->array_, this->size_ * sizeof(Unique<T>));
-    return copy;
-  }
-
-  void Clear() {
-    size_ = 0;
-  }
-
-  inline int size() const {
-    return size_;
-  }
-
-  inline Unique<T> at(int index) const {
-    DCHECK(index >= 0 && index < size_);
-    return array_[index];
-  }
-
- private:
-  // These sets should be small, since operations are implemented with simple
-  // linear algorithms. Enforce a maximum size.
-  static const int kMaxCapacity = 65535;
-
-  uint16_t size_;
-  uint16_t capacity_;
-  Unique<T>* array_;
-
-  // Grow the size of internal storage to be at least {size} elements.
-  void Grow(int size, Zone* zone) {
-    CHECK(size < kMaxCapacity);  // Enforce maximum size.
-    if (capacity_ < size) {
-      int new_capacity = 2 * capacity_ + size;
-      if (new_capacity > kMaxCapacity) new_capacity = kMaxCapacity;
-      Unique<T>* new_array = zone->NewArray<Unique<T> >(new_capacity);
-      if (size_ > 0) {
-        memcpy(new_array, array_, size_ * sizeof(Unique<T>));
-      }
-      capacity_ = new_capacity;
-      array_ = new_array;
-    }
-  }
-};
-
-}  // namespace internal
-}  // namespace v8
-
-#endif  // V8_UNIQUE_H_