1 // Copyright 2012 the V8 project authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef V8_DATAFLOW_H_ 6 #define V8_DATAFLOW_H_ 7 8 #include "src/v8.h" 9 10 #include "src/allocation.h" 11 #include "src/ast.h" 12 #include "src/compiler.h" 13 #include "src/zone-inl.h" 14 15 namespace v8 { 16 namespace internal { 17 18 class BitVector: public ZoneObject { 19 public: 20 // Iterator for the elements of this BitVector. 21 class Iterator BASE_EMBEDDED { 22 public: 23 explicit Iterator(BitVector* target) 24 : target_(target), 25 current_index_(0), 26 current_value_(target->data_[0]), 27 current_(-1) { 28 DCHECK(target->data_length_ > 0); 29 Advance(); 30 } 31 ~Iterator() { } 32 33 bool Done() const { return current_index_ >= target_->data_length_; } 34 void Advance(); 35 36 int Current() const { 37 DCHECK(!Done()); 38 return current_; 39 } 40 41 private: 42 uint32_t SkipZeroBytes(uint32_t val) { 43 while ((val & 0xFF) == 0) { 44 val >>= 8; 45 current_ += 8; 46 } 47 return val; 48 } 49 uint32_t SkipZeroBits(uint32_t val) { 50 while ((val & 0x1) == 0) { 51 val >>= 1; 52 current_++; 53 } 54 return val; 55 } 56 57 BitVector* target_; 58 int current_index_; 59 uint32_t current_value_; 60 int current_; 61 62 friend class BitVector; 63 }; 64 65 BitVector(int length, Zone* zone) 66 : length_(length), 67 data_length_(SizeFor(length)), 68 data_(zone->NewArray<uint32_t>(data_length_)) { 69 DCHECK(length > 0); 70 Clear(); 71 } 72 73 BitVector(const BitVector& other, Zone* zone) 74 : length_(other.length()), 75 data_length_(SizeFor(length_)), 76 data_(zone->NewArray<uint32_t>(data_length_)) { 77 CopyFrom(other); 78 } 79 80 static int SizeFor(int length) { 81 return 1 + ((length - 1) / 32); 82 } 83 84 BitVector& operator=(const BitVector& rhs) { 85 if (this != &rhs) CopyFrom(rhs); 86 return *this; 87 } 88 89 void CopyFrom(const BitVector& other) { 90 DCHECK(other.length() <= length()); 91 for (int i = 0; i < other.data_length_; i++) { 92 data_[i] = other.data_[i]; 93 } 94 for (int i = other.data_length_; i < data_length_; i++) { 95 data_[i] = 0; 96 } 97 } 98 99 bool Contains(int i) const { 100 DCHECK(i >= 0 && i < length()); 101 uint32_t block = data_[i / 32]; 102 return (block & (1U << (i % 32))) != 0; 103 } 104 105 void Add(int i) { 106 DCHECK(i >= 0 && i < length()); 107 data_[i / 32] |= (1U << (i % 32)); 108 } 109 110 void Remove(int i) { 111 DCHECK(i >= 0 && i < length()); 112 data_[i / 32] &= ~(1U << (i % 32)); 113 } 114 115 void Union(const BitVector& other) { 116 DCHECK(other.length() == length()); 117 for (int i = 0; i < data_length_; i++) { 118 data_[i] |= other.data_[i]; 119 } 120 } 121 122 bool UnionIsChanged(const BitVector& other) { 123 DCHECK(other.length() == length()); 124 bool changed = false; 125 for (int i = 0; i < data_length_; i++) { 126 uint32_t old_data = data_[i]; 127 data_[i] |= other.data_[i]; 128 if (data_[i] != old_data) changed = true; 129 } 130 return changed; 131 } 132 133 void Intersect(const BitVector& other) { 134 DCHECK(other.length() == length()); 135 for (int i = 0; i < data_length_; i++) { 136 data_[i] &= other.data_[i]; 137 } 138 } 139 140 bool IntersectIsChanged(const BitVector& other) { 141 DCHECK(other.length() == length()); 142 bool changed = false; 143 for (int i = 0; i < data_length_; i++) { 144 uint32_t old_data = data_[i]; 145 data_[i] &= other.data_[i]; 146 if (data_[i] != old_data) changed = true; 147 } 148 return changed; 149 } 150 151 void Subtract(const BitVector& other) { 152 DCHECK(other.length() == length()); 153 for (int i = 0; i < data_length_; i++) { 154 data_[i] &= ~other.data_[i]; 155 } 156 } 157 158 void Clear() { 159 for (int i = 0; i < data_length_; i++) { 160 data_[i] = 0; 161 } 162 } 163 164 bool IsEmpty() const { 165 for (int i = 0; i < data_length_; i++) { 166 if (data_[i] != 0) return false; 167 } 168 return true; 169 } 170 171 bool Equals(const BitVector& other) { 172 for (int i = 0; i < data_length_; i++) { 173 if (data_[i] != other.data_[i]) return false; 174 } 175 return true; 176 } 177 178 int Count() const; 179 180 int length() const { return length_; } 181 182 #ifdef DEBUG 183 void Print(); 184 #endif 185 186 private: 187 int length_; 188 int data_length_; 189 uint32_t* data_; 190 }; 191 192 193 class GrowableBitVector BASE_EMBEDDED { 194 public: 195 class Iterator BASE_EMBEDDED { 196 public: 197 Iterator(const GrowableBitVector* target, Zone* zone) 198 : it_(target->bits_ == NULL 199 ? new(zone) BitVector(1, zone) 200 : target->bits_) { } 201 bool Done() const { return it_.Done(); } 202 void Advance() { it_.Advance(); } 203 int Current() const { return it_.Current(); } 204 private: 205 BitVector::Iterator it_; 206 }; 207 208 GrowableBitVector() : bits_(NULL) { } 209 GrowableBitVector(int length, Zone* zone) 210 : bits_(new(zone) BitVector(length, zone)) { } 211 212 bool Contains(int value) const { 213 if (!InBitsRange(value)) return false; 214 return bits_->Contains(value); 215 } 216 217 void Add(int value, Zone* zone) { 218 EnsureCapacity(value, zone); 219 bits_->Add(value); 220 } 221 222 void Union(const GrowableBitVector& other, Zone* zone) { 223 for (Iterator it(&other, zone); !it.Done(); it.Advance()) { 224 Add(it.Current(), zone); 225 } 226 } 227 228 void Clear() { if (bits_ != NULL) bits_->Clear(); } 229 230 private: 231 static const int kInitialLength = 1024; 232 233 bool InBitsRange(int value) const { 234 return bits_ != NULL && bits_->length() > value; 235 } 236 237 void EnsureCapacity(int value, Zone* zone) { 238 if (InBitsRange(value)) return; 239 int new_length = bits_ == NULL ? kInitialLength : bits_->length(); 240 while (new_length <= value) new_length *= 2; 241 BitVector* new_bits = new(zone) BitVector(new_length, zone); 242 if (bits_ != NULL) new_bits->CopyFrom(*bits_); 243 bits_ = new_bits; 244 } 245 246 BitVector* bits_; 247 }; 248 249 } // namespace internal 250 } // namespace v8 251 252 #endif // V8_DATAFLOW_H_ 253
