convert BitVector to use pointer size blocks

src/bit-vector.h

Index: src/bit-vector.h
diff --git a/src/data-flow.h b/src/bit-vector.h
similarity index 79%
rename from src/data-flow.h
rename to src/bit-vector.h
index bfd238d24ee326d52bdc902792f2d71a0ab8c59f..9fc747d06fae6ea0cf454a7d14047a595f832966 100644
--- a/src/data-flow.h
+++ b/src/bit-vector.h
@@ -15,7 +15,7 @@
 namespace v8 {
 namespace internal {
 
-class BitVector: public ZoneObject {
+class BitVector : public ZoneObject {
  public:
   // Iterator for the elements of this BitVector.
   class Iterator BASE_EMBEDDED {
@@ -28,7 +28,7 @@ class BitVector: public ZoneObject {
       DCHECK(target->data_length_ > 0);
       Advance();
     }
-    ~Iterator() { }
+    ~Iterator() {}
 
     bool Done() const { return current_index_ >= target_->data_length_; }
     void Advance();
@@ -39,14 +39,14 @@ class BitVector: public ZoneObject {
     }
 
    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_++;
@@ -56,16 +56,20 @@ class BitVector: public ZoneObject {
 
     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();
   }
@@ -73,18 +77,11 @@ class BitVector: public ZoneObject {
   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());
@@ -98,18 +95,18 @@ class BitVector: public ZoneObject {
 
   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) {
@@ -123,7 +120,7 @@ class BitVector: public ZoneObject {
     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;
     }
@@ -141,7 +138,7 @@ class BitVector: public ZoneObject {
     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;
     }
@@ -184,9 +181,11 @@ class BitVector: public ZoneObject {
 #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);
 };
 
 
@@ -195,19 +194,19 @@ class GrowableBitVector BASE_EMBEDDED {
   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;
@@ -225,7 +224,9 @@ class GrowableBitVector BASE_EMBEDDED {
     }
   }
 
-  void Clear() { if (bits_ != NULL) bits_->Clear(); }
+  void Clear() {
+    if (bits_ != NULL) bits_->Clear();
+  }
 
  private:
   static const int kInitialLength = 1024;
@@ -238,7 +239,7 @@ class GrowableBitVector BASE_EMBEDDED {
     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;
   }