Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 1 | // Copyright 2016 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 | #include "src/interpreter/bytecode-register-optimizer.h" |
| 6 | |
| 7 | namespace v8 { |
| 8 | namespace internal { |
| 9 | namespace interpreter { |
| 10 | |
| 11 | const uint32_t BytecodeRegisterOptimizer::kInvalidEquivalenceId; |
| 12 | |
| 13 | // A class for tracking the state of a register. This class tracks |
| 14 | // which equivalence set a register is a member of and also whether a |
| 15 | // register is materialized in the bytecode stream. |
| 16 | class BytecodeRegisterOptimizer::RegisterInfo final : public ZoneObject { |
| 17 | public: |
| 18 | RegisterInfo(Register reg, uint32_t equivalence_id, bool materialized) |
| 19 | : register_(reg), |
| 20 | equivalence_id_(equivalence_id), |
| 21 | materialized_(materialized), |
| 22 | next_(this), |
| 23 | prev_(this) {} |
| 24 | |
| 25 | void AddToEquivalenceSetOf(RegisterInfo* info); |
| 26 | void MoveToNewEquivalenceSet(uint32_t equivalence_id, bool materialized); |
| 27 | bool IsOnlyMemberOfEquivalenceSet() const; |
| 28 | bool IsOnlyMaterializedMemberOfEquivalenceSet() const; |
| 29 | bool IsInSameEquivalenceSet(RegisterInfo* info) const; |
| 30 | |
| 31 | // Get a member of this register's equivalence set that is |
| 32 | // materialized. The materialized equivalent will be this register |
| 33 | // if it is materialized. Returns nullptr if no materialized |
| 34 | // equivalent exists. |
| 35 | RegisterInfo* GetMaterializedEquivalent(); |
| 36 | |
| 37 | // Get a member of this register's equivalence set that is |
| 38 | // materialized and not register |reg|. The materialized equivalent |
| 39 | // will be this register if it is materialized. Returns nullptr if |
| 40 | // no materialized equivalent exists. |
| 41 | RegisterInfo* GetMaterializedEquivalentOtherThan(Register reg); |
| 42 | |
| 43 | // Get a member of this register's equivalence set that is intended |
| 44 | // to be materialized in place of this register (which is currently |
| 45 | // materialized). The best candidate is deemed to be the register |
| 46 | // with the lowest index as this permits temporary registers to be |
| 47 | // removed from the bytecode stream. Returns nullptr if no candidate |
| 48 | // exists. |
| 49 | RegisterInfo* GetEquivalentToMaterialize(); |
| 50 | |
| 51 | // Get an equivalent register. Returns this if none exists. |
| 52 | RegisterInfo* GetEquivalent(); |
| 53 | |
| 54 | Register register_value() const { return register_; } |
| 55 | bool materialized() const { return materialized_; } |
| 56 | void set_materialized(bool materialized) { materialized_ = materialized; } |
| 57 | void set_equivalence_id(uint32_t equivalence_id) { |
| 58 | equivalence_id_ = equivalence_id; |
| 59 | } |
| 60 | uint32_t equivalence_id() const { return equivalence_id_; } |
| 61 | |
| 62 | private: |
| 63 | Register register_; |
| 64 | uint32_t equivalence_id_; |
| 65 | bool materialized_; |
| 66 | |
| 67 | // Equivalence set pointers. |
| 68 | RegisterInfo* next_; |
| 69 | RegisterInfo* prev_; |
| 70 | |
| 71 | DISALLOW_COPY_AND_ASSIGN(RegisterInfo); |
| 72 | }; |
| 73 | |
| 74 | void BytecodeRegisterOptimizer::RegisterInfo::AddToEquivalenceSetOf( |
| 75 | RegisterInfo* info) { |
| 76 | DCHECK_NE(kInvalidEquivalenceId, info->equivalence_id()); |
| 77 | // Fix old list |
| 78 | next_->prev_ = prev_; |
| 79 | prev_->next_ = next_; |
| 80 | // Add to new list. |
| 81 | next_ = info->next_; |
| 82 | prev_ = info; |
| 83 | prev_->next_ = this; |
| 84 | next_->prev_ = this; |
| 85 | set_equivalence_id(info->equivalence_id()); |
| 86 | set_materialized(false); |
| 87 | } |
| 88 | |
| 89 | void BytecodeRegisterOptimizer::RegisterInfo::MoveToNewEquivalenceSet( |
| 90 | uint32_t equivalence_id, bool materialized) { |
| 91 | next_->prev_ = prev_; |
| 92 | prev_->next_ = next_; |
| 93 | next_ = prev_ = this; |
| 94 | equivalence_id_ = equivalence_id; |
| 95 | materialized_ = materialized; |
| 96 | } |
| 97 | |
| 98 | bool BytecodeRegisterOptimizer::RegisterInfo::IsOnlyMemberOfEquivalenceSet() |
| 99 | const { |
| 100 | return this->next_ == this; |
| 101 | } |
| 102 | |
| 103 | bool BytecodeRegisterOptimizer::RegisterInfo:: |
| 104 | IsOnlyMaterializedMemberOfEquivalenceSet() const { |
| 105 | DCHECK(materialized()); |
| 106 | |
| 107 | const RegisterInfo* visitor = this->next_; |
| 108 | while (visitor != this) { |
| 109 | if (visitor->materialized()) { |
| 110 | return false; |
| 111 | } |
| 112 | visitor = visitor->next_; |
| 113 | } |
| 114 | return true; |
| 115 | } |
| 116 | |
| 117 | bool BytecodeRegisterOptimizer::RegisterInfo::IsInSameEquivalenceSet( |
| 118 | RegisterInfo* info) const { |
| 119 | return equivalence_id() == info->equivalence_id(); |
| 120 | } |
| 121 | |
| 122 | BytecodeRegisterOptimizer::RegisterInfo* |
| 123 | BytecodeRegisterOptimizer::RegisterInfo::GetMaterializedEquivalent() { |
| 124 | RegisterInfo* visitor = this; |
| 125 | do { |
| 126 | if (visitor->materialized()) { |
| 127 | return visitor; |
| 128 | } |
| 129 | visitor = visitor->next_; |
| 130 | } while (visitor != this); |
| 131 | |
| 132 | return nullptr; |
| 133 | } |
| 134 | |
| 135 | BytecodeRegisterOptimizer::RegisterInfo* |
| 136 | BytecodeRegisterOptimizer::RegisterInfo::GetMaterializedEquivalentOtherThan( |
| 137 | Register reg) { |
| 138 | RegisterInfo* visitor = this; |
| 139 | do { |
| 140 | if (visitor->materialized() && visitor->register_value() != reg) { |
| 141 | return visitor; |
| 142 | } |
| 143 | visitor = visitor->next_; |
| 144 | } while (visitor != this); |
| 145 | |
| 146 | return nullptr; |
| 147 | } |
| 148 | |
| 149 | BytecodeRegisterOptimizer::RegisterInfo* |
| 150 | BytecodeRegisterOptimizer::RegisterInfo::GetEquivalentToMaterialize() { |
| 151 | DCHECK(this->materialized()); |
| 152 | RegisterInfo* visitor = this->next_; |
| 153 | RegisterInfo* best_info = nullptr; |
| 154 | while (visitor != this) { |
| 155 | if (visitor->materialized()) { |
| 156 | return nullptr; |
| 157 | } |
| 158 | if (best_info == nullptr || |
| 159 | visitor->register_value() < best_info->register_value()) { |
| 160 | best_info = visitor; |
| 161 | } |
| 162 | visitor = visitor->next_; |
| 163 | } |
| 164 | return best_info; |
| 165 | } |
| 166 | |
| 167 | BytecodeRegisterOptimizer::RegisterInfo* |
| 168 | BytecodeRegisterOptimizer::RegisterInfo::GetEquivalent() { |
| 169 | return next_; |
| 170 | } |
| 171 | |
| 172 | BytecodeRegisterOptimizer::BytecodeRegisterOptimizer( |
| 173 | Zone* zone, TemporaryRegisterAllocator* register_allocator, |
| 174 | int parameter_count, BytecodePipelineStage* next_stage) |
| 175 | : accumulator_(Register::virtual_accumulator()), |
| 176 | temporary_base_(register_allocator->allocation_base()), |
| 177 | register_info_table_(zone), |
| 178 | equivalence_id_(0), |
| 179 | next_stage_(next_stage), |
| 180 | flush_required_(false), |
| 181 | zone_(zone) { |
| 182 | register_allocator->set_observer(this); |
| 183 | |
| 184 | // Calculate offset so register index values can be mapped into |
| 185 | // a vector of register metadata. |
| 186 | if (parameter_count != 0) { |
| 187 | register_info_table_offset_ = |
| 188 | -Register::FromParameterIndex(0, parameter_count).index(); |
| 189 | } else { |
| 190 | // TODO(oth): This path shouldn't be necessary in bytecode generated |
| 191 | // from Javascript, but a set of tests do not include the JS receiver. |
| 192 | register_info_table_offset_ = -accumulator_.index(); |
| 193 | } |
| 194 | |
| 195 | // Initialize register map for parameters, locals, and the |
| 196 | // accumulator. |
| 197 | register_info_table_.resize(register_info_table_offset_ + |
| 198 | static_cast<size_t>(temporary_base_.index())); |
| 199 | for (size_t i = 0; i < register_info_table_.size(); ++i) { |
| 200 | register_info_table_[i] = new (zone) RegisterInfo( |
| 201 | RegisterFromRegisterInfoTableIndex(i), NextEquivalenceId(), true); |
| 202 | DCHECK_EQ(register_info_table_[i]->register_value().index(), |
| 203 | RegisterFromRegisterInfoTableIndex(i).index()); |
| 204 | } |
| 205 | accumulator_info_ = GetRegisterInfo(accumulator_); |
| 206 | DCHECK(accumulator_info_->register_value() == accumulator_); |
| 207 | } |
| 208 | |
| 209 | // override |
| 210 | Handle<BytecodeArray> BytecodeRegisterOptimizer::ToBytecodeArray( |
| 211 | int fixed_register_count, int parameter_count, |
| 212 | Handle<FixedArray> handler_table) { |
| 213 | FlushState(); |
| 214 | return next_stage_->ToBytecodeArray(fixed_register_count, parameter_count, |
| 215 | handler_table); |
| 216 | } |
| 217 | |
| 218 | // override |
| 219 | void BytecodeRegisterOptimizer::Write(BytecodeNode* node) { |
| 220 | // |
| 221 | // Transfers with observable registers as the destination will be |
| 222 | // immediately materialized so the source position information will |
| 223 | // be ordered correctly. |
| 224 | // |
| 225 | // Transfers without observable destination registers will initially |
| 226 | // be emitted as Nop's with the source position. They may, or may |
| 227 | // not, be materialized by the optimizer. However, the source |
| 228 | // position is not lost and being attached to a Nop is fine as the |
| 229 | // destination register is not observable in the debugger. |
| 230 | // |
| 231 | switch (node->bytecode()) { |
| 232 | case Bytecode::kLdar: { |
| 233 | DoLdar(node); |
| 234 | return; |
| 235 | } |
| 236 | case Bytecode::kStar: { |
| 237 | DoStar(node); |
| 238 | return; |
| 239 | } |
| 240 | case Bytecode::kMov: { |
| 241 | DoMov(node); |
| 242 | return; |
| 243 | } |
| 244 | default: |
| 245 | break; |
| 246 | } |
| 247 | |
| 248 | if (Bytecodes::IsJump(node->bytecode()) || |
| 249 | node->bytecode() == Bytecode::kDebugger || |
| 250 | node->bytecode() == Bytecode::kSuspendGenerator) { |
| 251 | // All state must be flushed before emitting |
| 252 | // - a jump (due to how bytecode offsets for jumps are evaluated), |
| 253 | // - a call to the debugger (as it can manipulate locals and parameters), |
| 254 | // - a generator suspend (as this involves saving all registers). |
| 255 | FlushState(); |
| 256 | } |
| 257 | |
| 258 | PrepareOperands(node); |
| 259 | WriteToNextStage(node); |
| 260 | } |
| 261 | |
| 262 | // override |
| 263 | void BytecodeRegisterOptimizer::WriteJump(BytecodeNode* node, |
| 264 | BytecodeLabel* label) { |
| 265 | FlushState(); |
| 266 | next_stage_->WriteJump(node, label); |
| 267 | } |
| 268 | |
| 269 | // override |
| 270 | void BytecodeRegisterOptimizer::BindLabel(BytecodeLabel* label) { |
| 271 | FlushState(); |
| 272 | next_stage_->BindLabel(label); |
| 273 | } |
| 274 | |
| 275 | // override |
| 276 | void BytecodeRegisterOptimizer::BindLabel(const BytecodeLabel& target, |
| 277 | BytecodeLabel* label) { |
| 278 | // There is no need to flush here, it will have been flushed when |target| |
| 279 | // was bound. |
| 280 | next_stage_->BindLabel(target, label); |
| 281 | } |
| 282 | |
| 283 | void BytecodeRegisterOptimizer::FlushState() { |
| 284 | if (!flush_required_) { |
| 285 | return; |
| 286 | } |
| 287 | |
| 288 | // Materialize all live registers and break equivalences. |
| 289 | size_t count = register_info_table_.size(); |
| 290 | for (size_t i = 0; i < count; ++i) { |
| 291 | RegisterInfo* reg_info = register_info_table_[i]; |
| 292 | if (reg_info->materialized()) { |
| 293 | // Walk equivalents of materialized registers, materializing |
| 294 | // each equivalent register as necessary and placing in their |
| 295 | // own equivalence set. |
| 296 | RegisterInfo* equivalent; |
| 297 | while ((equivalent = reg_info->GetEquivalent()) != reg_info) { |
| 298 | if (!equivalent->materialized()) { |
| 299 | OutputRegisterTransfer(reg_info, equivalent); |
| 300 | } |
| 301 | equivalent->MoveToNewEquivalenceSet(NextEquivalenceId(), true); |
| 302 | } |
| 303 | } |
| 304 | } |
| 305 | |
| 306 | flush_required_ = false; |
| 307 | } |
| 308 | |
| 309 | void BytecodeRegisterOptimizer::WriteToNextStage(BytecodeNode* node) const { |
| 310 | next_stage_->Write(node); |
| 311 | } |
| 312 | |
| 313 | void BytecodeRegisterOptimizer::WriteToNextStage( |
| 314 | BytecodeNode* node, const BytecodeSourceInfo& source_info) const { |
| 315 | if (source_info.is_valid()) { |
| 316 | node->source_info().Clone(source_info); |
| 317 | } |
| 318 | next_stage_->Write(node); |
| 319 | } |
| 320 | |
| 321 | void BytecodeRegisterOptimizer::OutputRegisterTransfer( |
| 322 | RegisterInfo* input_info, RegisterInfo* output_info, |
| 323 | const BytecodeSourceInfo& source_info) { |
| 324 | Register input = input_info->register_value(); |
| 325 | Register output = output_info->register_value(); |
| 326 | DCHECK_NE(input.index(), output.index()); |
| 327 | |
| 328 | if (input == accumulator_) { |
| 329 | uint32_t operand = static_cast<uint32_t>(output.ToOperand()); |
| 330 | BytecodeNode node(Bytecode::kStar, operand); |
| 331 | WriteToNextStage(&node, source_info); |
| 332 | } else if (output == accumulator_) { |
| 333 | uint32_t operand = static_cast<uint32_t>(input.ToOperand()); |
| 334 | BytecodeNode node(Bytecode::kLdar, operand); |
| 335 | WriteToNextStage(&node, source_info); |
| 336 | } else { |
| 337 | uint32_t operand0 = static_cast<uint32_t>(input.ToOperand()); |
| 338 | uint32_t operand1 = static_cast<uint32_t>(output.ToOperand()); |
| 339 | BytecodeNode node(Bytecode::kMov, operand0, operand1); |
| 340 | WriteToNextStage(&node, source_info); |
| 341 | } |
| 342 | output_info->set_materialized(true); |
| 343 | } |
| 344 | |
| 345 | void BytecodeRegisterOptimizer::CreateMaterializedEquivalent( |
| 346 | RegisterInfo* info) { |
| 347 | DCHECK(info->materialized()); |
| 348 | RegisterInfo* unmaterialized = info->GetEquivalentToMaterialize(); |
| 349 | if (unmaterialized) { |
| 350 | OutputRegisterTransfer(info, unmaterialized); |
| 351 | } |
| 352 | } |
| 353 | |
| 354 | BytecodeRegisterOptimizer::RegisterInfo* |
| 355 | BytecodeRegisterOptimizer::GetMaterializedEquivalent(RegisterInfo* info) { |
| 356 | return info->materialized() ? info : info->GetMaterializedEquivalent(); |
| 357 | } |
| 358 | |
| 359 | BytecodeRegisterOptimizer::RegisterInfo* |
| 360 | BytecodeRegisterOptimizer::GetMaterializedEquivalentNotAccumulator( |
| 361 | RegisterInfo* info) { |
| 362 | if (info->materialized()) { |
| 363 | return info; |
| 364 | } |
| 365 | |
| 366 | RegisterInfo* result = info->GetMaterializedEquivalentOtherThan(accumulator_); |
| 367 | if (result == nullptr) { |
| 368 | Materialize(info); |
| 369 | result = info; |
| 370 | } |
| 371 | DCHECK(result->register_value() != accumulator_); |
| 372 | return result; |
| 373 | } |
| 374 | |
| 375 | void BytecodeRegisterOptimizer::Materialize(RegisterInfo* info) { |
| 376 | if (!info->materialized()) { |
| 377 | RegisterInfo* materialized = info->GetMaterializedEquivalent(); |
| 378 | OutputRegisterTransfer(materialized, info); |
| 379 | } |
| 380 | } |
| 381 | |
| 382 | void BytecodeRegisterOptimizer::AddToEquivalenceSet( |
| 383 | RegisterInfo* set_member, RegisterInfo* non_set_member) { |
| 384 | non_set_member->AddToEquivalenceSetOf(set_member); |
| 385 | // Flushing is only required when two or more registers are placed |
| 386 | // in the same equivalence set. |
| 387 | flush_required_ = true; |
| 388 | } |
| 389 | |
| 390 | void BytecodeRegisterOptimizer::RegisterTransfer( |
| 391 | RegisterInfo* input_info, RegisterInfo* output_info, |
| 392 | const BytecodeSourceInfo& source_info) { |
| 393 | // Materialize an alternate in the equivalence set that |
| 394 | // |output_info| is leaving. |
| 395 | if (output_info->materialized()) { |
| 396 | CreateMaterializedEquivalent(output_info); |
| 397 | } |
| 398 | |
| 399 | // Add |output_info| to new equivalence set. |
| 400 | if (!output_info->IsInSameEquivalenceSet(input_info)) { |
| 401 | AddToEquivalenceSet(input_info, output_info); |
| 402 | } |
| 403 | |
| 404 | bool output_is_observable = |
| 405 | RegisterIsObservable(output_info->register_value()); |
| 406 | if (output_is_observable) { |
| 407 | // Force store to be emitted when register is observable. |
| 408 | output_info->set_materialized(false); |
| 409 | RegisterInfo* materialized_info = input_info->GetMaterializedEquivalent(); |
| 410 | OutputRegisterTransfer(materialized_info, output_info, source_info); |
| 411 | } else if (source_info.is_valid()) { |
| 412 | // Emit a placeholder nop to maintain source position info. |
| 413 | EmitNopForSourceInfo(source_info); |
| 414 | } |
| 415 | } |
| 416 | |
| 417 | void BytecodeRegisterOptimizer::EmitNopForSourceInfo( |
| 418 | const BytecodeSourceInfo& source_info) const { |
| 419 | DCHECK(source_info.is_valid()); |
| 420 | BytecodeNode nop(Bytecode::kNop); |
| 421 | nop.source_info().Clone(source_info); |
| 422 | WriteToNextStage(&nop); |
| 423 | } |
| 424 | |
| 425 | void BytecodeRegisterOptimizer::DoLdar(const BytecodeNode* const node) { |
| 426 | Register input = GetRegisterInputOperand( |
| 427 | 0, node->bytecode(), node->operands(), node->operand_count()); |
| 428 | RegisterInfo* input_info = GetRegisterInfo(input); |
| 429 | RegisterTransfer(input_info, accumulator_info_, node->source_info()); |
| 430 | } |
| 431 | |
| 432 | void BytecodeRegisterOptimizer::DoMov(const BytecodeNode* const node) { |
| 433 | Register input = GetRegisterInputOperand( |
| 434 | 0, node->bytecode(), node->operands(), node->operand_count()); |
| 435 | RegisterInfo* input_info = GetRegisterInfo(input); |
| 436 | Register output = GetRegisterOutputOperand( |
| 437 | 1, node->bytecode(), node->operands(), node->operand_count()); |
| 438 | RegisterInfo* output_info = GetOrCreateRegisterInfo(output); |
| 439 | RegisterTransfer(input_info, output_info, node->source_info()); |
| 440 | } |
| 441 | |
| 442 | void BytecodeRegisterOptimizer::DoStar(const BytecodeNode* const node) { |
| 443 | Register output = GetRegisterOutputOperand( |
| 444 | 0, node->bytecode(), node->operands(), node->operand_count()); |
| 445 | RegisterInfo* output_info = GetOrCreateRegisterInfo(output); |
| 446 | RegisterTransfer(accumulator_info_, output_info, node->source_info()); |
| 447 | } |
| 448 | |
| 449 | void BytecodeRegisterOptimizer::PrepareRegisterOutputOperand( |
| 450 | RegisterInfo* reg_info) { |
| 451 | if (reg_info->materialized()) { |
| 452 | CreateMaterializedEquivalent(reg_info); |
| 453 | } |
| 454 | reg_info->MoveToNewEquivalenceSet(NextEquivalenceId(), true); |
| 455 | } |
| 456 | |
| 457 | void BytecodeRegisterOptimizer::PrepareRegisterRangeOutputOperand( |
| 458 | Register start, int count) { |
| 459 | for (int i = 0; i < count; ++i) { |
| 460 | Register reg(start.index() + i); |
| 461 | RegisterInfo* reg_info = GetOrCreateRegisterInfo(reg); |
| 462 | PrepareRegisterOutputOperand(reg_info); |
| 463 | } |
| 464 | } |
| 465 | |
| 466 | Register BytecodeRegisterOptimizer::GetEquivalentRegisterForInputOperand( |
| 467 | Register reg) { |
| 468 | // For a temporary register, RegInfo state may need be created. For |
| 469 | // locals and parameters, the RegInfo state is created in the |
| 470 | // BytecodeRegisterOptimizer constructor. |
| 471 | RegisterInfo* reg_info = GetOrCreateRegisterInfo(reg); |
| 472 | if (reg_info->materialized()) { |
| 473 | return reg; |
| 474 | } else { |
| 475 | RegisterInfo* equivalent_info = |
| 476 | GetMaterializedEquivalentNotAccumulator(reg_info); |
| 477 | return equivalent_info->register_value(); |
| 478 | } |
| 479 | } |
| 480 | |
| 481 | void BytecodeRegisterOptimizer::PrepareRegisterInputOperand( |
| 482 | BytecodeNode* const node, Register reg, int operand_index) { |
| 483 | Register equivalent = GetEquivalentRegisterForInputOperand(reg); |
| 484 | node->operands()[operand_index] = |
| 485 | static_cast<uint32_t>(equivalent.ToOperand()); |
| 486 | } |
| 487 | |
| 488 | void BytecodeRegisterOptimizer::PrepareRegisterRangeInputOperand(Register start, |
| 489 | int count) { |
| 490 | for (int i = 0; i < count; ++i) { |
| 491 | Register current(start.index() + i); |
| 492 | RegisterInfo* input_info = GetRegisterInfo(current); |
| 493 | Materialize(input_info); |
| 494 | } |
| 495 | } |
| 496 | |
| 497 | void BytecodeRegisterOptimizer::PrepareRegisterOperands( |
| 498 | BytecodeNode* const node) { |
| 499 | // |
| 500 | // For each input operand, get a materialized equivalent if it is |
| 501 | // just a single register, otherwise materialize register range. |
| 502 | // Update operand_scale if necessary. |
| 503 | // |
| 504 | // For each output register about to be clobbered, materialize an |
| 505 | // equivalent if it exists. Put each register in it's own equivalence set. |
| 506 | // |
| 507 | int register_operand_bitmap = |
| 508 | Bytecodes::GetRegisterOperandBitmap(node->bytecode()); |
| 509 | const OperandType* operand_types = |
| 510 | Bytecodes::GetOperandTypes(node->bytecode()); |
| 511 | uint32_t* operands = node->operands(); |
| 512 | for (int i = 0; register_operand_bitmap != 0; |
| 513 | ++i, register_operand_bitmap >>= 1) { |
| 514 | if ((register_operand_bitmap & 1) == 0) { |
| 515 | continue; |
| 516 | } |
| 517 | OperandType operand_type = operand_types[i]; |
| 518 | int count = 0; |
| 519 | if (operand_types[i + 1] == OperandType::kRegCount) { |
| 520 | count = static_cast<int>(operands[i + 1]); |
| 521 | if (count == 0) { |
| 522 | continue; |
| 523 | } |
| 524 | } else { |
| 525 | count = Bytecodes::GetNumberOfRegistersRepresentedBy(operand_type); |
| 526 | } |
| 527 | |
| 528 | Register reg = Register::FromOperand(static_cast<int32_t>(operands[i])); |
| 529 | if (Bytecodes::IsRegisterInputOperandType(operand_type)) { |
| 530 | if (count == 1) { |
| 531 | PrepareRegisterInputOperand(node, reg, i); |
| 532 | } else if (count > 1) { |
| 533 | PrepareRegisterRangeInputOperand(reg, count); |
| 534 | } |
| 535 | } else if (Bytecodes::IsRegisterOutputOperandType(operand_type)) { |
| 536 | PrepareRegisterRangeOutputOperand(reg, count); |
| 537 | } |
| 538 | } |
| 539 | } |
| 540 | |
| 541 | void BytecodeRegisterOptimizer::PrepareAccumulator(BytecodeNode* const node) { |
| 542 | // Materialize the accumulator if it is read by the bytecode. The |
| 543 | // accumulator is special and no other register can be materialized |
| 544 | // in it's place. |
| 545 | if (Bytecodes::ReadsAccumulator(node->bytecode()) && |
| 546 | !accumulator_info_->materialized()) { |
| 547 | Materialize(accumulator_info_); |
| 548 | } |
| 549 | |
| 550 | // Materialize an equivalent to the accumulator if it will be |
| 551 | // clobbered when the bytecode is dispatched. |
| 552 | if (Bytecodes::WritesAccumulator(node->bytecode())) { |
| 553 | PrepareRegisterOutputOperand(accumulator_info_); |
| 554 | } |
| 555 | } |
| 556 | |
| 557 | void BytecodeRegisterOptimizer::PrepareOperands(BytecodeNode* const node) { |
| 558 | PrepareAccumulator(node); |
| 559 | PrepareRegisterOperands(node); |
| 560 | } |
| 561 | |
| 562 | // static |
| 563 | Register BytecodeRegisterOptimizer::GetRegisterInputOperand( |
| 564 | int index, Bytecode bytecode, const uint32_t* operands, int operand_count) { |
| 565 | DCHECK_LT(index, operand_count); |
| 566 | DCHECK(Bytecodes::IsRegisterInputOperandType( |
| 567 | Bytecodes::GetOperandType(bytecode, index))); |
| 568 | return OperandToRegister(operands[index]); |
| 569 | } |
| 570 | |
| 571 | // static |
| 572 | Register BytecodeRegisterOptimizer::GetRegisterOutputOperand( |
| 573 | int index, Bytecode bytecode, const uint32_t* operands, int operand_count) { |
| 574 | DCHECK_LT(index, operand_count); |
| 575 | DCHECK(Bytecodes::IsRegisterOutputOperandType( |
| 576 | Bytecodes::GetOperandType(bytecode, index))); |
| 577 | return OperandToRegister(operands[index]); |
| 578 | } |
| 579 | |
| 580 | BytecodeRegisterOptimizer::RegisterInfo* |
| 581 | BytecodeRegisterOptimizer::GetRegisterInfo(Register reg) { |
| 582 | size_t index = GetRegisterInfoTableIndex(reg); |
| 583 | return (index < register_info_table_.size()) ? register_info_table_[index] |
| 584 | : nullptr; |
| 585 | } |
| 586 | |
| 587 | BytecodeRegisterOptimizer::RegisterInfo* |
| 588 | BytecodeRegisterOptimizer::GetOrCreateRegisterInfo(Register reg) { |
| 589 | size_t index = GetRegisterInfoTableIndex(reg); |
| 590 | return index < register_info_table_.size() ? register_info_table_[index] |
| 591 | : NewRegisterInfo(reg); |
| 592 | } |
| 593 | |
| 594 | BytecodeRegisterOptimizer::RegisterInfo* |
| 595 | BytecodeRegisterOptimizer::NewRegisterInfo(Register reg) { |
| 596 | size_t index = GetRegisterInfoTableIndex(reg); |
| 597 | DCHECK_GE(index, register_info_table_.size()); |
| 598 | GrowRegisterMap(reg); |
| 599 | return register_info_table_[index]; |
| 600 | } |
| 601 | |
| 602 | void BytecodeRegisterOptimizer::GrowRegisterMap(Register reg) { |
| 603 | DCHECK(RegisterIsTemporary(reg)); |
| 604 | size_t index = GetRegisterInfoTableIndex(reg); |
| 605 | DCHECK_GE(index, register_info_table_.size()); |
| 606 | size_t new_size = index + 1; |
| 607 | size_t old_size = register_info_table_.size(); |
| 608 | register_info_table_.resize(new_size); |
| 609 | for (size_t i = old_size; i < new_size; ++i) { |
| 610 | register_info_table_[i] = new (zone()) RegisterInfo( |
| 611 | RegisterFromRegisterInfoTableIndex(i), NextEquivalenceId(), false); |
| 612 | } |
| 613 | } |
| 614 | |
| 615 | void BytecodeRegisterOptimizer::TemporaryRegisterFreeEvent(Register reg) { |
| 616 | RegisterInfo* info = GetRegisterInfo(reg); |
| 617 | if (info != nullptr) { |
| 618 | // If register is materialized and part of equivalence set, make |
| 619 | // sure another member of the set holds the value before the |
| 620 | // temporary register is removed. |
| 621 | if (info->materialized()) { |
| 622 | CreateMaterializedEquivalent(info); |
| 623 | } |
| 624 | info->MoveToNewEquivalenceSet(kInvalidEquivalenceId, false); |
| 625 | } |
| 626 | } |
| 627 | |
| 628 | } // namespace interpreter |
| 629 | } // namespace internal |
| 630 | } // namespace v8 |