Leon Clarke | 4515c47 | 2010-02-03 11:58:03 +0000 | [diff] [blame] | 1 | // Copyright 2010 the V8 project authors. All rights reserved. |
| 2 | // Redistribution and use in source and binary forms, with or without |
| 3 | // modification, are permitted provided that the following conditions are |
| 4 | // met: |
| 5 | // |
| 6 | // * Redistributions of source code must retain the above copyright |
| 7 | // notice, this list of conditions and the following disclaimer. |
| 8 | // * Redistributions in binary form must reproduce the above |
| 9 | // copyright notice, this list of conditions and the following |
| 10 | // disclaimer in the documentation and/or other materials provided |
| 11 | // with the distribution. |
| 12 | // * Neither the name of Google Inc. nor the names of its |
| 13 | // contributors may be used to endorse or promote products derived |
| 14 | // from this software without specific prior written permission. |
| 15 | // |
| 16 | // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 17 | // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 18 | // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 19 | // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| 20 | // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 21 | // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| 22 | // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 23 | // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 24 | // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 25 | // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| 26 | // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 27 | |
| 28 | #ifndef V8_DATAFLOW_H_ |
| 29 | #define V8_DATAFLOW_H_ |
| 30 | |
Steve Block | 6ded16b | 2010-05-10 14:33:55 +0100 | [diff] [blame] | 31 | #include "v8.h" |
| 32 | |
Leon Clarke | 4515c47 | 2010-02-03 11:58:03 +0000 | [diff] [blame] | 33 | #include "ast.h" |
Andrei Popescu | 3100271 | 2010-02-23 13:46:05 +0000 | [diff] [blame] | 34 | #include "compiler.h" |
Steve Block | 6ded16b | 2010-05-10 14:33:55 +0100 | [diff] [blame] | 35 | #include "zone-inl.h" |
Leon Clarke | 4515c47 | 2010-02-03 11:58:03 +0000 | [diff] [blame] | 36 | |
| 37 | namespace v8 { |
| 38 | namespace internal { |
| 39 | |
Steve Block | 6ded16b | 2010-05-10 14:33:55 +0100 | [diff] [blame] | 40 | // Forward declarations. |
| 41 | class Node; |
| 42 | |
| 43 | class BitVector: public ZoneObject { |
| 44 | public: |
Ben Murdoch | b0fe162 | 2011-05-05 13:52:32 +0100 | [diff] [blame] | 45 | // Iterator for the elements of this BitVector. |
| 46 | class Iterator BASE_EMBEDDED { |
| 47 | public: |
| 48 | explicit Iterator(BitVector* target) |
| 49 | : target_(target), |
| 50 | current_index_(0), |
| 51 | current_value_(target->data_[0]), |
| 52 | current_(-1) { |
| 53 | ASSERT(target->data_length_ > 0); |
| 54 | Advance(); |
| 55 | } |
| 56 | ~Iterator() { } |
Kristian Monsen | 80d68ea | 2010-09-08 11:05:35 +0100 | [diff] [blame] | 57 | |
Ben Murdoch | b0fe162 | 2011-05-05 13:52:32 +0100 | [diff] [blame] | 58 | bool Done() const { return current_index_ >= target_->data_length_; } |
| 59 | void Advance(); |
| 60 | |
| 61 | int Current() const { |
| 62 | ASSERT(!Done()); |
| 63 | return current_; |
| 64 | } |
| 65 | |
| 66 | private: |
| 67 | uint32_t SkipZeroBytes(uint32_t val) { |
| 68 | while ((val & 0xFF) == 0) { |
| 69 | val >>= 8; |
| 70 | current_ += 8; |
| 71 | } |
| 72 | return val; |
| 73 | } |
| 74 | uint32_t SkipZeroBits(uint32_t val) { |
| 75 | while ((val & 0x1) == 0) { |
| 76 | val >>= 1; |
| 77 | current_++; |
| 78 | } |
| 79 | return val; |
| 80 | } |
| 81 | |
| 82 | BitVector* target_; |
| 83 | int current_index_; |
| 84 | uint32_t current_value_; |
| 85 | int current_; |
| 86 | |
| 87 | friend class BitVector; |
| 88 | }; |
| 89 | |
| 90 | explicit BitVector(int length) |
| 91 | : length_(length), |
| 92 | data_length_(SizeFor(length)), |
Steve Block | 44f0eee | 2011-05-26 01:26:41 +0100 | [diff] [blame] | 93 | data_(ZONE->NewArray<uint32_t>(data_length_)) { |
Ben Murdoch | b0fe162 | 2011-05-05 13:52:32 +0100 | [diff] [blame] | 94 | ASSERT(length > 0); |
| 95 | Clear(); |
Steve Block | 6ded16b | 2010-05-10 14:33:55 +0100 | [diff] [blame] | 96 | } |
| 97 | |
| 98 | BitVector(const BitVector& other) |
| 99 | : length_(other.length()), |
| 100 | data_length_(SizeFor(length_)), |
Steve Block | 44f0eee | 2011-05-26 01:26:41 +0100 | [diff] [blame] | 101 | data_(ZONE->NewArray<uint32_t>(data_length_)) { |
Steve Block | 6ded16b | 2010-05-10 14:33:55 +0100 | [diff] [blame] | 102 | CopyFrom(other); |
| 103 | } |
| 104 | |
Ben Murdoch | b0fe162 | 2011-05-05 13:52:32 +0100 | [diff] [blame] | 105 | static int SizeFor(int length) { |
| 106 | return 1 + ((length - 1) / 32); |
Steve Block | 6ded16b | 2010-05-10 14:33:55 +0100 | [diff] [blame] | 107 | } |
| 108 | |
| 109 | BitVector& operator=(const BitVector& rhs) { |
| 110 | if (this != &rhs) CopyFrom(rhs); |
| 111 | return *this; |
| 112 | } |
| 113 | |
| 114 | void CopyFrom(const BitVector& other) { |
Steve Block | 9fac840 | 2011-05-12 15:51:54 +0100 | [diff] [blame] | 115 | ASSERT(other.length() <= length()); |
| 116 | for (int i = 0; i < other.data_length_; i++) { |
Steve Block | 6ded16b | 2010-05-10 14:33:55 +0100 | [diff] [blame] | 117 | data_[i] = other.data_[i]; |
| 118 | } |
Steve Block | 9fac840 | 2011-05-12 15:51:54 +0100 | [diff] [blame] | 119 | for (int i = other.data_length_; i < data_length_; i++) { |
| 120 | data_[i] = 0; |
| 121 | } |
Steve Block | 6ded16b | 2010-05-10 14:33:55 +0100 | [diff] [blame] | 122 | } |
| 123 | |
Ben Murdoch | b0fe162 | 2011-05-05 13:52:32 +0100 | [diff] [blame] | 124 | bool Contains(int i) const { |
Steve Block | 6ded16b | 2010-05-10 14:33:55 +0100 | [diff] [blame] | 125 | ASSERT(i >= 0 && i < length()); |
| 126 | uint32_t block = data_[i / 32]; |
| 127 | return (block & (1U << (i % 32))) != 0; |
| 128 | } |
| 129 | |
| 130 | void Add(int i) { |
| 131 | ASSERT(i >= 0 && i < length()); |
| 132 | data_[i / 32] |= (1U << (i % 32)); |
| 133 | } |
| 134 | |
| 135 | void Remove(int i) { |
| 136 | ASSERT(i >= 0 && i < length()); |
| 137 | data_[i / 32] &= ~(1U << (i % 32)); |
| 138 | } |
| 139 | |
| 140 | void Union(const BitVector& other) { |
| 141 | ASSERT(other.length() == length()); |
| 142 | for (int i = 0; i < data_length_; i++) { |
| 143 | data_[i] |= other.data_[i]; |
| 144 | } |
| 145 | } |
| 146 | |
Ben Murdoch | b0fe162 | 2011-05-05 13:52:32 +0100 | [diff] [blame] | 147 | bool UnionIsChanged(const BitVector& other) { |
| 148 | ASSERT(other.length() == length()); |
| 149 | bool changed = false; |
| 150 | for (int i = 0; i < data_length_; i++) { |
| 151 | uint32_t old_data = data_[i]; |
| 152 | data_[i] |= other.data_[i]; |
| 153 | if (data_[i] != old_data) changed = true; |
| 154 | } |
| 155 | return changed; |
| 156 | } |
| 157 | |
Steve Block | 6ded16b | 2010-05-10 14:33:55 +0100 | [diff] [blame] | 158 | void Intersect(const BitVector& other) { |
| 159 | ASSERT(other.length() == length()); |
| 160 | for (int i = 0; i < data_length_; i++) { |
| 161 | data_[i] &= other.data_[i]; |
| 162 | } |
| 163 | } |
| 164 | |
| 165 | void Subtract(const BitVector& other) { |
| 166 | ASSERT(other.length() == length()); |
| 167 | for (int i = 0; i < data_length_; i++) { |
| 168 | data_[i] &= ~other.data_[i]; |
| 169 | } |
| 170 | } |
| 171 | |
| 172 | void Clear() { |
| 173 | for (int i = 0; i < data_length_; i++) { |
| 174 | data_[i] = 0; |
| 175 | } |
| 176 | } |
| 177 | |
| 178 | bool IsEmpty() const { |
| 179 | for (int i = 0; i < data_length_; i++) { |
| 180 | if (data_[i] != 0) return false; |
| 181 | } |
| 182 | return true; |
| 183 | } |
| 184 | |
| 185 | bool Equals(const BitVector& other) { |
| 186 | for (int i = 0; i < data_length_; i++) { |
| 187 | if (data_[i] != other.data_[i]) return false; |
| 188 | } |
| 189 | return true; |
| 190 | } |
| 191 | |
| 192 | int length() const { return length_; } |
| 193 | |
| 194 | #ifdef DEBUG |
| 195 | void Print(); |
| 196 | #endif |
| 197 | |
| 198 | private: |
| 199 | int length_; |
| 200 | int data_length_; |
| 201 | uint32_t* data_; |
| 202 | }; |
| 203 | |
| 204 | |
Ben Murdoch | b0fe162 | 2011-05-05 13:52:32 +0100 | [diff] [blame] | 205 | // An implementation of a sparse set whose elements are drawn from integers |
| 206 | // in the range [0..universe_size[. It supports constant-time Contains, |
| 207 | // destructive Add, and destructuve Remove operations and linear-time (in |
| 208 | // the number of elements) destructive Union. |
| 209 | class SparseSet: public ZoneObject { |
| 210 | public: |
| 211 | // Iterator for sparse set elements. Elements should not be added or |
| 212 | // removed during iteration. |
| 213 | class Iterator BASE_EMBEDDED { |
| 214 | public: |
| 215 | explicit Iterator(SparseSet* target) : target_(target), current_(0) { |
| 216 | ASSERT(++target->iterator_count_ > 0); |
| 217 | } |
| 218 | ~Iterator() { |
| 219 | ASSERT(target_->iterator_count_-- > 0); |
| 220 | } |
| 221 | bool Done() const { return current_ >= target_->dense_.length(); } |
| 222 | void Advance() { |
| 223 | ASSERT(!Done()); |
| 224 | ++current_; |
| 225 | } |
| 226 | int Current() { |
| 227 | ASSERT(!Done()); |
| 228 | return target_->dense_[current_]; |
| 229 | } |
| 230 | |
| 231 | private: |
| 232 | SparseSet* target_; |
| 233 | int current_; |
| 234 | |
| 235 | friend class SparseSet; |
| 236 | }; |
| 237 | |
| 238 | explicit SparseSet(int universe_size) |
| 239 | : dense_(4), |
Steve Block | 44f0eee | 2011-05-26 01:26:41 +0100 | [diff] [blame] | 240 | sparse_(ZONE->NewArray<int>(universe_size)) { |
Ben Murdoch | b0fe162 | 2011-05-05 13:52:32 +0100 | [diff] [blame] | 241 | #ifdef DEBUG |
| 242 | size_ = universe_size; |
| 243 | iterator_count_ = 0; |
| 244 | #endif |
| 245 | } |
| 246 | |
| 247 | bool Contains(int n) const { |
| 248 | ASSERT(0 <= n && n < size_); |
| 249 | int dense_index = sparse_[n]; |
| 250 | return (0 <= dense_index) && |
| 251 | (dense_index < dense_.length()) && |
| 252 | (dense_[dense_index] == n); |
| 253 | } |
| 254 | |
| 255 | void Add(int n) { |
| 256 | ASSERT(0 <= n && n < size_); |
| 257 | ASSERT(iterator_count_ == 0); |
| 258 | if (!Contains(n)) { |
| 259 | sparse_[n] = dense_.length(); |
| 260 | dense_.Add(n); |
| 261 | } |
| 262 | } |
| 263 | |
| 264 | void Remove(int n) { |
| 265 | ASSERT(0 <= n && n < size_); |
| 266 | ASSERT(iterator_count_ == 0); |
| 267 | if (Contains(n)) { |
| 268 | int dense_index = sparse_[n]; |
| 269 | int last = dense_.RemoveLast(); |
| 270 | if (dense_index < dense_.length()) { |
| 271 | dense_[dense_index] = last; |
| 272 | sparse_[last] = dense_index; |
| 273 | } |
| 274 | } |
| 275 | } |
| 276 | |
| 277 | void Union(const SparseSet& other) { |
| 278 | for (int i = 0; i < other.dense_.length(); ++i) { |
| 279 | Add(other.dense_[i]); |
| 280 | } |
| 281 | } |
| 282 | |
| 283 | private: |
| 284 | // The set is implemented as a pair of a growable dense list and an |
| 285 | // uninitialized sparse array. |
| 286 | ZoneList<int> dense_; |
| 287 | int* sparse_; |
| 288 | #ifdef DEBUG |
| 289 | int size_; |
| 290 | int iterator_count_; |
| 291 | #endif |
| 292 | }; |
| 293 | |
| 294 | |
Steve Block | 6ded16b | 2010-05-10 14:33:55 +0100 | [diff] [blame] | 295 | // Simple fixed-capacity list-based worklist (managed as a queue) of |
| 296 | // pointers to T. |
| 297 | template<typename T> |
| 298 | class WorkList BASE_EMBEDDED { |
| 299 | public: |
| 300 | // The worklist cannot grow bigger than size. We keep one item empty to |
| 301 | // distinguish between empty and full. |
| 302 | explicit WorkList(int size) |
| 303 | : capacity_(size + 1), head_(0), tail_(0), queue_(capacity_) { |
| 304 | for (int i = 0; i < capacity_; i++) queue_.Add(NULL); |
| 305 | } |
| 306 | |
| 307 | bool is_empty() { return head_ == tail_; } |
| 308 | |
| 309 | bool is_full() { |
| 310 | // The worklist is full if head is at 0 and tail is at capacity - 1: |
| 311 | // head == 0 && tail == capacity-1 ==> tail - head == capacity - 1 |
| 312 | // or if tail is immediately to the left of head: |
| 313 | // tail+1 == head ==> tail - head == -1 |
| 314 | int diff = tail_ - head_; |
| 315 | return (diff == -1 || diff == capacity_ - 1); |
| 316 | } |
| 317 | |
| 318 | void Insert(T* item) { |
| 319 | ASSERT(!is_full()); |
| 320 | queue_[tail_++] = item; |
| 321 | if (tail_ == capacity_) tail_ = 0; |
| 322 | } |
| 323 | |
| 324 | T* Remove() { |
| 325 | ASSERT(!is_empty()); |
| 326 | T* item = queue_[head_++]; |
| 327 | if (head_ == capacity_) head_ = 0; |
| 328 | return item; |
| 329 | } |
| 330 | |
| 331 | private: |
| 332 | int capacity_; // Including one empty slot. |
| 333 | int head_; // Where the first item is. |
| 334 | int tail_; // Where the next inserted item will go. |
| 335 | List<T*> queue_; |
| 336 | }; |
| 337 | |
Steve Block | 053d10c | 2011-06-13 19:13:29 +0100 | [diff] [blame] | 338 | |
| 339 | // Computes the set of assigned variables and annotates variables proxies |
| 340 | // that are trivial sub-expressions and for-loops where the loop variable |
| 341 | // is guaranteed to be a smi. |
| 342 | class AssignedVariablesAnalyzer : public AstVisitor { |
| 343 | public: |
| 344 | static bool Analyze(CompilationInfo* info); |
| 345 | |
| 346 | private: |
| 347 | AssignedVariablesAnalyzer(CompilationInfo* info, int bits); |
| 348 | bool Analyze(); |
| 349 | |
| 350 | Variable* FindSmiLoopVariable(ForStatement* stmt); |
| 351 | |
| 352 | int BitIndex(Variable* var); |
| 353 | |
| 354 | void RecordAssignedVar(Variable* var); |
| 355 | |
| 356 | void MarkIfTrivial(Expression* expr); |
| 357 | |
| 358 | // Visits an expression saving the accumulator before, clearing |
| 359 | // it before visting and restoring it after visiting. |
| 360 | void ProcessExpression(Expression* expr); |
| 361 | |
| 362 | // AST node visit functions. |
| 363 | #define DECLARE_VISIT(type) virtual void Visit##type(type* node); |
| 364 | AST_NODE_LIST(DECLARE_VISIT) |
| 365 | #undef DECLARE_VISIT |
| 366 | |
| 367 | CompilationInfo* info_; |
| 368 | |
| 369 | // Accumulator for assigned variables set. |
| 370 | BitVector av_; |
| 371 | |
| 372 | DISALLOW_COPY_AND_ASSIGN(AssignedVariablesAnalyzer); |
| 373 | }; |
| 374 | |
| 375 | |
Leon Clarke | 4515c47 | 2010-02-03 11:58:03 +0000 | [diff] [blame] | 376 | } } // namespace v8::internal |
| 377 | |
Andrei Popescu | 402d937 | 2010-02-26 13:31:12 +0000 | [diff] [blame] | 378 | |
Leon Clarke | 4515c47 | 2010-02-03 11:58:03 +0000 | [diff] [blame] | 379 | #endif // V8_DATAFLOW_H_ |