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data-flow.h
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27 
28 #ifndef V8_DATAFLOW_H_
29 #define V8_DATAFLOW_H_
30 
31 #include "v8.h"
32 
33 #include "allocation.h"
34 #include "ast.h"
35 #include "compiler.h"
36 #include "zone-inl.h"
37 
38 namespace v8 {
39 namespace internal {
40 
41 class BitVector: public ZoneObject {
42  public:
43  // Iterator for the elements of this BitVector.
44  class Iterator BASE_EMBEDDED {
45  public:
46  explicit Iterator(BitVector* target)
47  : target_(target),
48  current_index_(0),
49  current_value_(target->data_[0]),
50  current_(-1) {
51  ASSERT(target->data_length_ > 0);
52  Advance();
53  }
54  ~Iterator() { }
55 
56  bool Done() const { return current_index_ >= target_->data_length_; }
57  void Advance();
58 
59  int Current() const {
60  ASSERT(!Done());
61  return current_;
62  }
63 
64  private:
65  uint32_t SkipZeroBytes(uint32_t val) {
66  while ((val & 0xFF) == 0) {
67  val >>= 8;
68  current_ += 8;
69  }
70  return val;
71  }
72  uint32_t SkipZeroBits(uint32_t val) {
73  while ((val & 0x1) == 0) {
74  val >>= 1;
75  current_++;
76  }
77  return val;
78  }
79 
80  BitVector* target_;
81  int current_index_;
82  uint32_t current_value_;
83  int current_;
84 
85  friend class BitVector;
86  };
87 
88  BitVector(int length, Zone* zone)
89  : length_(length),
90  data_length_(SizeFor(length)),
91  data_(zone->NewArray<uint32_t>(data_length_)) {
92  ASSERT(length > 0);
93  Clear();
94  }
95 
96  BitVector(const BitVector& other, Zone* zone)
97  : length_(other.length()),
98  data_length_(SizeFor(length_)),
99  data_(zone->NewArray<uint32_t>(data_length_)) {
100  CopyFrom(other);
101  }
102 
103  static int SizeFor(int length) {
104  return 1 + ((length - 1) / 32);
105  }
106 
108  if (this != &rhs) CopyFrom(rhs);
109  return *this;
110  }
111 
112  void CopyFrom(const BitVector& other) {
113  ASSERT(other.length() <= length());
114  for (int i = 0; i < other.data_length_; i++) {
115  data_[i] = other.data_[i];
116  }
117  for (int i = other.data_length_; i < data_length_; i++) {
118  data_[i] = 0;
119  }
120  }
121 
122  bool Contains(int i) const {
123  ASSERT(i >= 0 && i < length());
124  uint32_t block = data_[i / 32];
125  return (block & (1U << (i % 32))) != 0;
126  }
127 
128  void Add(int i) {
129  ASSERT(i >= 0 && i < length());
130  data_[i / 32] |= (1U << (i % 32));
131  }
132 
133  void Remove(int i) {
134  ASSERT(i >= 0 && i < length());
135  data_[i / 32] &= ~(1U << (i % 32));
136  }
137 
138  void Union(const BitVector& other) {
139  ASSERT(other.length() == length());
140  for (int i = 0; i < data_length_; i++) {
141  data_[i] |= other.data_[i];
142  }
143  }
144 
145  bool UnionIsChanged(const BitVector& other) {
146  ASSERT(other.length() == length());
147  bool changed = false;
148  for (int i = 0; i < data_length_; i++) {
149  uint32_t old_data = data_[i];
150  data_[i] |= other.data_[i];
151  if (data_[i] != old_data) changed = true;
152  }
153  return changed;
154  }
155 
156  void Intersect(const BitVector& other) {
157  ASSERT(other.length() == length());
158  for (int i = 0; i < data_length_; i++) {
159  data_[i] &= other.data_[i];
160  }
161  }
162 
163  void Subtract(const BitVector& other) {
164  ASSERT(other.length() == length());
165  for (int i = 0; i < data_length_; i++) {
166  data_[i] &= ~other.data_[i];
167  }
168  }
169 
170  void Clear() {
171  for (int i = 0; i < data_length_; i++) {
172  data_[i] = 0;
173  }
174  }
175 
176  bool IsEmpty() const {
177  for (int i = 0; i < data_length_; i++) {
178  if (data_[i] != 0) return false;
179  }
180  return true;
181  }
182 
183  bool Equals(const BitVector& other) {
184  for (int i = 0; i < data_length_; i++) {
185  if (data_[i] != other.data_[i]) return false;
186  }
187  return true;
188  }
189 
190  int length() const { return length_; }
191 
192 #ifdef DEBUG
193  void Print();
194 #endif
195 
196  private:
197  int length_;
198  int data_length_;
199  uint32_t* data_;
200 };
201 
202 } } // namespace v8::internal
203 
204 
205 #endif // V8_DATAFLOW_H_
static int SizeFor(int length)
Definition: data-flow.h:103
int current_
void Intersect(const BitVector &other)
Definition: data-flow.h:156
#define ASSERT(condition)
Definition: checks.h:270
v8::Handle< v8::Value > Print(const v8::Arguments &args)
bool Contains(int i) const
Definition: data-flow.h:122
int length() const
Definition: data-flow.h:190
bool IsEmpty() const
Definition: data-flow.h:176
T * NewArray(size_t size)
Definition: allocation.h:83
bool UnionIsChanged(const BitVector &other)
Definition: data-flow.h:145
void CopyFrom(const BitVector &other)
Definition: data-flow.h:112
void Union(const BitVector &other)
Definition: data-flow.h:138
BitVector & operator=(const BitVector &rhs)
Definition: data-flow.h:107
bool Equals(const BitVector &other)
Definition: data-flow.h:183
BitVector(const BitVector &other, Zone *zone)
Definition: data-flow.h:96
void Subtract(const BitVector &other)
Definition: data-flow.h:163
BitVector(int length, Zone *zone)
Definition: data-flow.h:88