convert BitVector to use pointer size blocks

src/bit-vector.h

 // Copyright 2012 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_DATAFLOW_H_
 #define V8_DATAFLOW_H_
 
 #include "src/v8.h"
 
 #include "src/allocation.h"
 #include "src/ast.h"
 #include "src/compiler.h"
 #include "src/zone-inl.h"
 
 namespace v8 {
 namespace internal {
 
-class BitVector: public ZoneObject {
+class BitVector : public ZoneObject {
  public:
   // Iterator for the elements of this BitVector.
   class Iterator BASE_EMBEDDED {
    public:
     explicit Iterator(BitVector* target)
         : target_(target),
           current_index_(0),
           current_value_(target->data_[0]),
           current_(-1) {
       DCHECK(target->data_length_ > 0);
       Advance();
     }
-    ~Iterator() { }
+    ~Iterator() {}
 
     bool Done() const { return current_index_ >= target_->data_length_; }
     void Advance();
 
     int Current() const {
       DCHECK(!Done());
       return current_;
     }
 
    private:
-    uint32_t SkipZeroBytes(uint32_t val) {
+    uintptr_t SkipZeroBytes(uintptr_t val) {
       while ((val & 0xFF) == 0) {
         val >>= 8;
         current_ += 8;
       }
       return val;
     }
-    uint32_t SkipZeroBits(uint32_t val) {
+    uintptr_t SkipZeroBits(uintptr_t val) {
       while ((val & 0x1) == 0) {
         val >>= 1;
         current_++;
       }
       return val;
     }
 
     BitVector* target_;
     int current_index_;
-    uint32_t current_value_;
+    uintptr_t current_value_;
     int current_;
 
     friend class BitVector;
   };
 
+  static const int kDataBits = kPointerSize * 8;
+  static const int kDataBitShift = kPointerSize == 8 ? 6 : 5;
+  static const uintptr_t kOne = 1;  // This saves some static_casts.
+
   BitVector(int length, Zone* zone)
       : length_(length),
         data_length_(SizeFor(length)),
-        data_(zone->NewArray<uint32_t>(data_length_)) {
+        data_(zone->NewArray<uintptr_t>(data_length_)) {
     DCHECK(length > 0);
     Clear();
   }
 
   BitVector(const BitVector& other, Zone* zone)
       : length_(other.length()),
         data_length_(SizeFor(length_)),
-        data_(zone->NewArray<uint32_t>(data_length_)) {
+        data_(zone->NewArray<uintptr_t>(data_length_)) {
     CopyFrom(other);
   }
 
-  static int SizeFor(int length) {
-    return 1 + ((length - 1) / 32);
-  }
-
-  BitVector& operator=(const BitVector& rhs) {
-    if (this != &rhs) CopyFrom(rhs);
-    return *this;
-  }
+  static int SizeFor(int length) { return 1 + ((length - 1) / kDataBits); }
 
   void CopyFrom(const BitVector& other) {
     DCHECK(other.length() <= length());
     for (int i = 0; i < other.data_length_; i++) {
       data_[i] = other.data_[i];
     }
     for (int i = other.data_length_; i < data_length_; i++) {
       data_[i] = 0;
     }
   }
 
   bool Contains(int i) const {
     DCHECK(i >= 0 && i < length());
-    uint32_t block = data_[i / 32];
-    return (block & (1U << (i % 32))) != 0;
+    uintptr_t block = data_[i / kDataBits];
+    return (block & (kOne << (i % kDataBits))) != 0;
   }
 
   void Add(int i) {
     DCHECK(i >= 0 && i < length());
-    data_[i / 32] |= (1U << (i % 32));
+    data_[i / kDataBits] |= (kOne << (i % kDataBits));
   }
 
   void Remove(int i) {
     DCHECK(i >= 0 && i < length());
-    data_[i / 32] &= ~(1U << (i % 32));
+    data_[i / kDataBits] &= ~(kOne << (i % kDataBits));
   }
 
   void Union(const BitVector& other) {
     DCHECK(other.length() == length());
     for (int i = 0; i < data_length_; i++) {
       data_[i] |= other.data_[i];
     }
   }
 
   bool UnionIsChanged(const BitVector& other) {
     DCHECK(other.length() == length());
     bool changed = false;
     for (int i = 0; i < data_length_; i++) {
-      uint32_t old_data = data_[i];
+      uintptr_t old_data = data_[i];
       data_[i] |= other.data_[i];
       if (data_[i] != old_data) changed = true;
     }
     return changed;
   }
 
   void Intersect(const BitVector& other) {
     DCHECK(other.length() == length());
     for (int i = 0; i < data_length_; i++) {
       data_[i] &= other.data_[i];
     }
   }
 
   bool IntersectIsChanged(const BitVector& other) {
     DCHECK(other.length() == length());
     bool changed = false;
     for (int i = 0; i < data_length_; i++) {
-      uint32_t old_data = data_[i];
+      uintptr_t old_data = data_[i];
       data_[i] &= other.data_[i];
       if (data_[i] != old_data) changed = true;
     }
     return changed;
   }
 
   void Subtract(const BitVector& other) {
     DCHECK(other.length() == length());
     for (int i = 0; i < data_length_; i++) {
       data_[i] &= ~other.data_[i];
@@ skipping 22 matching lines @@
 
   int Count() const;
 
   int length() const { return length_; }
 
 #ifdef DEBUG
   void Print();
 #endif
 
  private:
-  int length_;
-  int data_length_;
-  uint32_t* data_;
+  const int length_;
+  const int data_length_;
+  uintptr_t* const data_;
+
+  DISALLOW_COPY_AND_ASSIGN(BitVector);
 };
 
 
 class GrowableBitVector BASE_EMBEDDED {
  public:
   class Iterator BASE_EMBEDDED {
    public:
     Iterator(const GrowableBitVector* target, Zone* zone)
-        : it_(target->bits_ == NULL
-              ? new(zone) BitVector(1, zone)
-              : target->bits_) { }
+        : it_(target->bits_ == NULL ? new (zone) BitVector(1, zone)
+                                    : target->bits_) {}
     bool Done() const { return it_.Done(); }
     void Advance() { it_.Advance(); }
     int Current() const { return it_.Current(); }
+
    private:
     BitVector::Iterator it_;
   };
 
-  GrowableBitVector() : bits_(NULL) { }
+  GrowableBitVector() : bits_(NULL) {}
   GrowableBitVector(int length, Zone* zone)
-      : bits_(new(zone) BitVector(length, zone)) { }
+      : bits_(new (zone) BitVector(length, zone)) {}
 
   bool Contains(int value) const {
     if (!InBitsRange(value)) return false;
     return bits_->Contains(value);
   }
 
   void Add(int value, Zone* zone) {
     EnsureCapacity(value, zone);
     bits_->Add(value);
   }
 
   void Union(const GrowableBitVector& other, Zone* zone) {
     for (Iterator it(&other, zone); !it.Done(); it.Advance()) {
       Add(it.Current(), zone);
     }
   }
 
-  void Clear() { if (bits_ != NULL) bits_->Clear(); }
+  void Clear() {
+    if (bits_ != NULL) bits_->Clear();
+  }
 
  private:
   static const int kInitialLength = 1024;
 
   bool InBitsRange(int value) const {
     return bits_ != NULL && bits_->length() > value;
   }
 
   void EnsureCapacity(int value, Zone* zone) {
     if (InBitsRange(value)) return;
     int new_length = bits_ == NULL ? kInitialLength : bits_->length();
     while (new_length <= value) new_length *= 2;
-    BitVector* new_bits = new(zone) BitVector(new_length, zone);
+    BitVector* new_bits = new (zone) BitVector(new_length, zone);
     if (bits_ != NULL) new_bits->CopyFrom(*bits_);
     bits_ = new_bits;
   }
 
   BitVector* bits_;
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_DATAFLOW_H_