src/v8/src/lithium.cc

   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 #include "src/v8.h"
   6 #include "src/lithium.h"
   7 #include "src/scopes.h"
   8 #include "src/serialize.h"
   9
  10 #if V8_TARGET_ARCH_IA32
  11 #include "src/ia32/lithium-ia32.h"
  12 #include "src/ia32/lithium-codegen-ia32.h"
  13 #elif V8_TARGET_ARCH_X64
  14 #include "src/x64/lithium-x64.h"
  15 #include "src/x64/lithium-codegen-x64.h"
  16 #elif V8_TARGET_ARCH_ARM
  17 #include "src/arm/lithium-arm.h"
  18 #include "src/arm/lithium-codegen-arm.h"
  19 #elif V8_TARGET_ARCH_MIPS
  20 #include "src/mips/lithium-mips.h"
  21 #include "src/mips/lithium-codegen-mips.h"
  22 #elif V8_TARGET_ARCH_ARM64
  23 #include "src/arm64/lithium-arm64.h"
  24 #include "src/arm64/lithium-codegen-arm64.h"
  25 #elif V8_TARGET_ARCH_X87
  26 #include "src/x87/lithium-x87.h"
  27 #include "src/x87/lithium-codegen-x87.h"
  28 #else
  29 #error "Unknown architecture."
  30 #endif
  31
  32 namespace v8 {
  33 namespace internal {
  34
  35
  36 void LOperand::PrintTo(StringStream* stream) {
  37   LUnallocated* unalloc = NULL;
  38   switch (kind()) {
  39     case INVALID:
  40       stream->Add("(0)");
  41       break;
  42     case UNALLOCATED:
  43       unalloc = LUnallocated::cast(this);
  44       stream->Add("v%d", unalloc->virtual_register());
  45       if (unalloc->basic_policy() == LUnallocated::FIXED_SLOT) {
  46         stream->Add("(=%dS)", unalloc->fixed_slot_index());
  47         break;
  48       }
  49       switch (unalloc->extended_policy()) {
  50         case LUnallocated::NONE:
  51           break;
  52         case LUnallocated::FIXED_REGISTER: {
  53           int reg_index = unalloc->fixed_register_index();
  54           const char* register_name =
  55               Register::AllocationIndexToString(reg_index);
  56           stream->Add("(=%s)", register_name);
  57           break;
  58         }
  59         case LUnallocated::FIXED_DOUBLE_REGISTER: {
  60           int reg_index = unalloc->fixed_register_index();
  61           const char* double_register_name =
  62               DoubleRegister::AllocationIndexToString(reg_index);
  63           stream->Add("(=%s)", double_register_name);
  64           break;
  65         }
  66         case LUnallocated::MUST_HAVE_REGISTER:
  67           stream->Add("(R)");
  68           break;
  69         case LUnallocated::MUST_HAVE_DOUBLE_REGISTER:
  70           stream->Add("(D)");
  71           break;
  72         case LUnallocated::WRITABLE_REGISTER:
  73           stream->Add("(WR)");
  74           break;
  75         case LUnallocated::SAME_AS_FIRST_INPUT:
  76           stream->Add("(1)");
  77           break;
  78         case LUnallocated::ANY:
  79           stream->Add("(-)");
  80           break;
  81       }
  82       break;
  83     case CONSTANT_OPERAND:
  84       stream->Add("[constant:%d]", index());
  85       break;
  86     case STACK_SLOT:
  87       stream->Add("[stack:%d]", index());
  88       break;
  89     case DOUBLE_STACK_SLOT:
  90       stream->Add("[double_stack:%d]", index());
  91       break;
  92     case REGISTER:
  93       stream->Add("[%s|R]", Register::AllocationIndexToString(index()));
  94       break;
  95     case DOUBLE_REGISTER:
  96       stream->Add("[%s|R]", DoubleRegister::AllocationIndexToString(index()));
  97       break;
  98   }
  99 }
 100
 101
 102 template<LOperand::Kind kOperandKind, int kNumCachedOperands>
 103 LSubKindOperand<kOperandKind, kNumCachedOperands>*
 104 LSubKindOperand<kOperandKind, kNumCachedOperands>::cache = NULL;
 105
 106
 107 template<LOperand::Kind kOperandKind, int kNumCachedOperands>
 108 void LSubKindOperand<kOperandKind, kNumCachedOperands>::SetUpCache() {
 109   if (cache) return;
 110   cache = new LSubKindOperand[kNumCachedOperands];
 111   for (int i = 0; i < kNumCachedOperands; i++) {
 112     cache[i].ConvertTo(kOperandKind, i);
 113   }
 114 }
 115
 116
 117 template<LOperand::Kind kOperandKind, int kNumCachedOperands>
 118 void LSubKindOperand<kOperandKind, kNumCachedOperands>::TearDownCache() {
 119   delete[] cache;
 120 }
 121
 122
 123 void LOperand::SetUpCaches() {
 124 #define LITHIUM_OPERAND_SETUP(name, type, number) L##name::SetUpCache();
 125   LITHIUM_OPERAND_LIST(LITHIUM_OPERAND_SETUP)
 126 #undef LITHIUM_OPERAND_SETUP
 127 }
 128
 129
 130 void LOperand::TearDownCaches() {
 131 #define LITHIUM_OPERAND_TEARDOWN(name, type, number) L##name::TearDownCache();
 132   LITHIUM_OPERAND_LIST(LITHIUM_OPERAND_TEARDOWN)
 133 #undef LITHIUM_OPERAND_TEARDOWN
 134 }
 135
 136
 137 bool LParallelMove::IsRedundant() const {
 138   for (int i = 0; i < move_operands_.length(); ++i) {
 139     if (!move_operands_[i].IsRedundant()) return false;
 140   }
 141   return true;
 142 }
 143
 144
 145 void LParallelMove::PrintDataTo(StringStream* stream) const {
 146   bool first = true;
 147   for (int i = 0; i < move_operands_.length(); ++i) {
 148     if (!move_operands_[i].IsEliminated()) {
 149       LOperand* source = move_operands_[i].source();
 150       LOperand* destination = move_operands_[i].destination();
 151       if (!first) stream->Add(" ");
 152       first = false;
 153       if (source->Equals(destination)) {
 154         destination->PrintTo(stream);
 155       } else {
 156         destination->PrintTo(stream);
 157         stream->Add(" = ");
 158         source->PrintTo(stream);
 159       }
 160       stream->Add(";");
 161     }
 162   }
 163 }
 164
 165
 166 void LEnvironment::PrintTo(StringStream* stream) {
 167   stream->Add("[id=%d|", ast_id().ToInt());
 168   if (deoptimization_index() != Safepoint::kNoDeoptimizationIndex) {
 169     stream->Add("deopt_id=%d|", deoptimization_index());
 170   }
 171   stream->Add("parameters=%d|", parameter_count());
 172   stream->Add("arguments_stack_height=%d|", arguments_stack_height());
 173   for (int i = 0; i < values_.length(); ++i) {
 174     if (i != 0) stream->Add(";");
 175     if (values_[i] == NULL) {
 176       stream->Add("[hole]");
 177     } else {
 178       values_[i]->PrintTo(stream);
 179     }
 180   }
 181   stream->Add("]");
 182 }
 183
 184
 185 void LPointerMap::RecordPointer(LOperand* op, Zone* zone) {
 186   // Do not record arguments as pointers.
 187   if (op->IsStackSlot() && op->index() < 0) return;
 188   ASSERT(!op->IsDoubleRegister() && !op->IsDoubleStackSlot());
 189   pointer_operands_.Add(op, zone);
 190 }
 191
 192
 193 void LPointerMap::RemovePointer(LOperand* op) {
 194   // Do not record arguments as pointers.
 195   if (op->IsStackSlot() && op->index() < 0) return;
 196   ASSERT(!op->IsDoubleRegister() && !op->IsDoubleStackSlot());
 197   for (int i = 0; i < pointer_operands_.length(); ++i) {
 198     if (pointer_operands_[i]->Equals(op)) {
 199       pointer_operands_.Remove(i);
 200       --i;
 201     }
 202   }
 203 }
 204
 205
 206 void LPointerMap::RecordUntagged(LOperand* op, Zone* zone) {
 207   // Do not record arguments as pointers.
 208   if (op->IsStackSlot() && op->index() < 0) return;
 209   ASSERT(!op->IsDoubleRegister() && !op->IsDoubleStackSlot());
 210   untagged_operands_.Add(op, zone);
 211 }
 212
 213
 214 void LPointerMap::PrintTo(StringStream* stream) {
 215   stream->Add("{");
 216   for (int i = 0; i < pointer_operands_.length(); ++i) {
 217     if (i != 0) stream->Add(";");
 218     pointer_operands_[i]->PrintTo(stream);
 219   }
 220   stream->Add("}");
 221 }
 222
 223
 224 int StackSlotOffset(int index) {
 225   if (index >= 0) {
 226     // Local or spill slot. Skip the frame pointer, function, and
 227     // context in the fixed part of the frame.
 228     return -(index + 1) * kPointerSize -
 229         StandardFrameConstants::kFixedFrameSizeFromFp;
 230   } else {
 231     // Incoming parameter. Skip the return address.
 232     return -(index + 1) * kPointerSize + kFPOnStackSize + kPCOnStackSize;
 233   }
 234 }
 235
 236
 237 LChunk::LChunk(CompilationInfo* info, HGraph* graph)
 238     : spill_slot_count_(0),
 239       info_(info),
 240       graph_(graph),
 241       instructions_(32, graph->zone()),
 242       pointer_maps_(8, graph->zone()),
 243       inlined_closures_(1, graph->zone()),
 244       deprecation_dependencies_(MapLess(), MapAllocator(graph->zone())),
 245       stability_dependencies_(MapLess(), MapAllocator(graph->zone())) {
 246 }
 247
 248
 249 LLabel* LChunk::GetLabel(int block_id) const {
 250   HBasicBlock* block = graph_->blocks()->at(block_id);
 251   int first_instruction = block->first_instruction_index();
 252   return LLabel::cast(instructions_[first_instruction]);
 253 }
 254
 255
 256 int LChunk::LookupDestination(int block_id) const {
 257   LLabel* cur = GetLabel(block_id);
 258   while (cur->replacement() != NULL) {
 259     cur = cur->replacement();
 260   }
 261   return cur->block_id();
 262 }
 263
 264 Label* LChunk::GetAssemblyLabel(int block_id) const {
 265   LLabel* label = GetLabel(block_id);
 266   ASSERT(!label->HasReplacement());
 267   return label->label();
 268 }
 269
 270
 271 void LChunk::MarkEmptyBlocks() {
 272   LPhase phase("L_Mark empty blocks", this);
 273   for (int i = 0; i < graph()->blocks()->length(); ++i) {
 274     HBasicBlock* block = graph()->blocks()->at(i);
 275     int first = block->first_instruction_index();
 276     int last = block->last_instruction_index();
 277     LInstruction* first_instr = instructions()->at(first);
 278     LInstruction* last_instr = instructions()->at(last);
 279
 280     LLabel* label = LLabel::cast(first_instr);
 281     if (last_instr->IsGoto()) {
 282       LGoto* goto_instr = LGoto::cast(last_instr);
 283       if (label->IsRedundant() &&
 284           !label->is_loop_header()) {
 285         bool can_eliminate = true;
 286         for (int i = first + 1; i < last && can_eliminate; ++i) {
 287           LInstruction* cur = instructions()->at(i);
 288           if (cur->IsGap()) {
 289             LGap* gap = LGap::cast(cur);
 290             if (!gap->IsRedundant()) {
 291               can_eliminate = false;
 292             }
 293           } else {
 294             can_eliminate = false;
 295           }
 296         }
 297         if (can_eliminate) {
 298           label->set_replacement(GetLabel(goto_instr->block_id()));
 299         }
 300       }
 301     }
 302   }
 303 }
 304
 305
 306 void LChunk::AddInstruction(LInstruction* instr, HBasicBlock* block) {
 307   LInstructionGap* gap = new(graph_->zone()) LInstructionGap(block);
 308   gap->set_hydrogen_value(instr->hydrogen_value());
 309   int index = -1;
 310   if (instr->IsControl()) {
 311     instructions_.Add(gap, zone());
 312     index = instructions_.length();
 313     instructions_.Add(instr, zone());
 314   } else {
 315     index = instructions_.length();
 316     instructions_.Add(instr, zone());
 317     instructions_.Add(gap, zone());
 318   }
 319   if (instr->HasPointerMap()) {
 320     pointer_maps_.Add(instr->pointer_map(), zone());
 321     instr->pointer_map()->set_lithium_position(index);
 322   }
 323 }
 324
 325
 326 LConstantOperand* LChunk::DefineConstantOperand(HConstant* constant) {
 327   return LConstantOperand::Create(constant->id(), zone());
 328 }
 329
 330
 331 int LChunk::GetParameterStackSlot(int index) const {
 332   // The receiver is at index 0, the first parameter at index 1, so we
 333   // shift all parameter indexes down by the number of parameters, and
 334   // make sure they end up negative so they are distinguishable from
 335   // spill slots.
 336   int result = index - info()->num_parameters() - 1;
 337
 338   ASSERT(result < 0);
 339   return result;
 340 }
 341
 342
 343 // A parameter relative to ebp in the arguments stub.
 344 int LChunk::ParameterAt(int index) {
 345   ASSERT(-1 <= index);  // -1 is the receiver.
 346   return (1 + info()->scope()->num_parameters() - index) *
 347       kPointerSize;
 348 }
 349
 350
 351 LGap* LChunk::GetGapAt(int index) const {
 352   return LGap::cast(instructions_[index]);
 353 }
 354
 355
 356 bool LChunk::IsGapAt(int index) const {
 357   return instructions_[index]->IsGap();
 358 }
 359
 360
 361 int LChunk::NearestGapPos(int index) const {
 362   while (!IsGapAt(index)) index--;
 363   return index;
 364 }
 365
 366
 367 void LChunk::AddGapMove(int index, LOperand* from, LOperand* to) {
 368   GetGapAt(index)->GetOrCreateParallelMove(
 369       LGap::START, zone())->AddMove(from, to, zone());
 370 }
 371
 372
 373 HConstant* LChunk::LookupConstant(LConstantOperand* operand) const {
 374   return HConstant::cast(graph_->LookupValue(operand->index()));
 375 }
 376
 377
 378 Representation LChunk::LookupLiteralRepresentation(
 379     LConstantOperand* operand) const {
 380   return graph_->LookupValue(operand->index())->representation();
 381 }
 382
 383
 384 void LChunk::CommitDependencies(Handle<Code> code) const {
 385   for (MapSet::const_iterator it = deprecation_dependencies_.begin(),
 386        iend = deprecation_dependencies_.end(); it != iend; ++it) {
 387     Handle<Map> map = *it;
 388     ASSERT(!map->is_deprecated());
 389     ASSERT(map->CanBeDeprecated());
 390     Map::AddDependentCode(map, DependentCode::kTransitionGroup, code);
 391   }
 392
 393   for (MapSet::const_iterator it = stability_dependencies_.begin(),
 394        iend = stability_dependencies_.end(); it != iend; ++it) {
 395     Handle<Map> map = *it;
 396     ASSERT(map->is_stable());
 397     ASSERT(map->CanTransition());
 398     Map::AddDependentCode(map, DependentCode::kPrototypeCheckGroup, code);
 399   }
 400
 401   info_->CommitDependencies(code);
 402 }
 403
 404
 405 LChunk* LChunk::NewChunk(HGraph* graph) {
 406   DisallowHandleAllocation no_handles;
 407   DisallowHeapAllocation no_gc;
 408   graph->DisallowAddingNewValues();
 409   int values = graph->GetMaximumValueID();
 410   CompilationInfo* info = graph->info();
 411   if (values > LUnallocated::kMaxVirtualRegisters) {
 412     info->set_bailout_reason(kNotEnoughVirtualRegistersForValues);
 413     return NULL;
 414   }
 415   LAllocator allocator(values, graph);
 416   LChunkBuilder builder(info, graph, &allocator);
 417   LChunk* chunk = builder.Build();
 418   if (chunk == NULL) return NULL;
 419
 420   if (!allocator.Allocate(chunk)) {
 421     info->set_bailout_reason(kNotEnoughVirtualRegistersRegalloc);
 422     return NULL;
 423   }
 424
 425   chunk->set_allocated_double_registers(
 426       allocator.assigned_double_registers());
 427
 428   return chunk;
 429 }
 430
 431
 432 Handle<Code> LChunk::Codegen() {
 433   MacroAssembler assembler(info()->isolate(), NULL, 0);
 434   LOG_CODE_EVENT(info()->isolate(),
 435                  CodeStartLinePosInfoRecordEvent(
 436                      assembler.positions_recorder()));
 437   LCodeGen generator(this, &assembler, info());
 438
 439   MarkEmptyBlocks();
 440
 441   if (generator.GenerateCode()) {
 442     generator.CheckEnvironmentUsage();
 443     CodeGenerator::MakeCodePrologue(info(), "optimized");
 444     Code::Flags flags = info()->flags();
 445     Handle<Code> code =
 446         CodeGenerator::MakeCodeEpilogue(&assembler, flags, info());
 447     generator.FinishCode(code);
 448     CommitDependencies(code);
 449     code->set_is_crankshafted(true);
 450     void* jit_handler_data =
 451         assembler.positions_recorder()->DetachJITHandlerData();
 452     LOG_CODE_EVENT(info()->isolate(),
 453                    CodeEndLinePosInfoRecordEvent(*code, jit_handler_data));
 454
 455     CodeGenerator::PrintCode(code, info());
 456     ASSERT(!(info()->isolate()->serializer_enabled() &&
 457              info()->GetMustNotHaveEagerFrame() &&
 458              generator.NeedsEagerFrame()));
 459     return code;
 460   }
 461   assembler.AbortedCodeGeneration();
 462   return Handle<Code>::null();
 463 }
 464
 465
 466 void LChunk::set_allocated_double_registers(BitVector* allocated_registers) {
 467   allocated_double_registers_ = allocated_registers;
 468   BitVector* doubles = allocated_double_registers();
 469   BitVector::Iterator iterator(doubles);
 470   while (!iterator.Done()) {
 471     if (info()->saves_caller_doubles()) {
 472       if (kDoubleSize == kPointerSize * 2) {
 473         spill_slot_count_ += 2;
 474       } else {
 475         spill_slot_count_++;
 476       }
 477     }
 478     iterator.Advance();
 479   }
 480 }
 481
 482
 483 LEnvironment* LChunkBuilderBase::CreateEnvironment(
 484     HEnvironment* hydrogen_env,
 485     int* argument_index_accumulator,
 486     ZoneList<HValue*>* objects_to_materialize) {
 487   if (hydrogen_env == NULL) return NULL;
 488
 489   LEnvironment* outer = CreateEnvironment(hydrogen_env->outer(),
 490                                           argument_index_accumulator,
 491                                           objects_to_materialize);
 492   BailoutId ast_id = hydrogen_env->ast_id();
 493   ASSERT(!ast_id.IsNone() ||
 494          hydrogen_env->frame_type() != JS_FUNCTION);
 495   int value_count = hydrogen_env->length() - hydrogen_env->specials_count();
 496   LEnvironment* result =
 497       new(zone()) LEnvironment(hydrogen_env->closure(),
 498                                hydrogen_env->frame_type(),
 499                                ast_id,
 500                                hydrogen_env->parameter_count(),
 501                                argument_count_,
 502                                value_count,
 503                                outer,
 504                                hydrogen_env->entry(),
 505                                zone());
 506   int argument_index = *argument_index_accumulator;
 507
 508   // Store the environment description into the environment
 509   // (with holes for nested objects)
 510   for (int i = 0; i < hydrogen_env->length(); ++i) {
 511     if (hydrogen_env->is_special_index(i)) continue;
 512
 513     LOperand* op;
 514     HValue* value = hydrogen_env->values()->at(i);
 515     CHECK(!value->IsPushArguments());  // Do not deopt outgoing arguments
 516     if (value->IsArgumentsObject() || value->IsCapturedObject()) {
 517       op = LEnvironment::materialization_marker();
 518     } else {
 519       op = UseAny(value);
 520     }
 521     result->AddValue(op,
 522                      value->representation(),
 523                      value->CheckFlag(HInstruction::kUint32));
 524   }
 525
 526   // Recursively store the nested objects into the environment
 527   for (int i = 0; i < hydrogen_env->length(); ++i) {
 528     if (hydrogen_env->is_special_index(i)) continue;
 529
 530     HValue* value = hydrogen_env->values()->at(i);
 531     if (value->IsArgumentsObject() || value->IsCapturedObject()) {
 532       AddObjectToMaterialize(value, objects_to_materialize, result);
 533     }
 534   }
 535
 536   if (hydrogen_env->frame_type() == JS_FUNCTION) {
 537     *argument_index_accumulator = argument_index;
 538   }
 539
 540   return result;
 541 }
 542
 543
 544 // Add an object to the supplied environment and object materialization list.
 545 //
 546 // Notes:
 547 //
 548 // We are building three lists here:
 549 //
 550 // 1. In the result->object_mapping_ list (added to by the
 551 //    LEnvironment::Add*Object methods), we store the lengths (number
 552 //    of fields) of the captured objects in depth-first traversal order, or
 553 //    in case of duplicated objects, we store the index to the duplicate object
 554 //    (with a tag to differentiate between captured and duplicated objects).
 555 //
 556 // 2. The object fields are stored in the result->values_ list
 557 //    (added to by the LEnvironment.AddValue method) sequentially as lists
 558 //    of fields with holes for nested objects (the holes will be expanded
 559 //    later by LCodegen::AddToTranslation according to the
 560 //    LEnvironment.object_mapping_ list).
 561 //
 562 // 3. The auxiliary objects_to_materialize array stores the hydrogen values
 563 //    in the same order as result->object_mapping_ list. This is used
 564 //    to detect duplicate values and calculate the corresponding object index.
 565 void LChunkBuilderBase::AddObjectToMaterialize(HValue* value,
 566     ZoneList<HValue*>* objects_to_materialize, LEnvironment* result) {
 567   int object_index = objects_to_materialize->length();
 568   // Store the hydrogen value into the de-duplication array
 569   objects_to_materialize->Add(value, zone());
 570   // Find out whether we are storing a duplicated value
 571   int previously_materialized_object = -1;
 572   for (int prev = 0; prev < object_index; ++prev) {
 573     if (objects_to_materialize->at(prev) == value) {
 574       previously_materialized_object = prev;
 575       break;
 576     }
 577   }
 578   // Store the captured object length (or duplicated object index)
 579   // into the environment. For duplicated objects, we stop here.
 580   int length = value->OperandCount();
 581   bool is_arguments = value->IsArgumentsObject();
 582   if (previously_materialized_object >= 0) {
 583     result->AddDuplicateObject(previously_materialized_object);
 584     return;
 585   } else {
 586     result->AddNewObject(is_arguments ? length - 1 : length, is_arguments);
 587   }
 588   // Store the captured object's fields into the environment
 589   for (int i = is_arguments ? 1 : 0; i < length; ++i) {
 590     LOperand* op;
 591     HValue* arg_value = value->OperandAt(i);
 592     if (arg_value->IsArgumentsObject() || arg_value->IsCapturedObject()) {
 593       // Insert a hole for nested objects
 594       op = LEnvironment::materialization_marker();
 595     } else {
 596       ASSERT(!arg_value->IsPushArguments());
 597       // For ordinary values, tell the register allocator we need the value
 598       // to be alive here
 599       op = UseAny(arg_value);
 600     }
 601     result->AddValue(op,
 602                      arg_value->representation(),
 603                      arg_value->CheckFlag(HInstruction::kUint32));
 604   }
 605   // Recursively store all the nested captured objects into the environment
 606   for (int i = is_arguments ? 1 : 0; i < length; ++i) {
 607     HValue* arg_value = value->OperandAt(i);
 608     if (arg_value->IsArgumentsObject() || arg_value->IsCapturedObject()) {
 609       AddObjectToMaterialize(arg_value, objects_to_materialize, result);
 610     }
 611   }
 612 }
 613
 614
 615 LPhase::~LPhase() {
 616   if (ShouldProduceTraceOutput()) {
 617     isolate()->GetHTracer()->TraceLithium(name(), chunk_);
 618   }
 619 }
 620
 621
 622 } }  // namespace v8::internal