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/crankshaft/lithium.h"
6
7#include "src/ast/scopes.h"
8#include "src/codegen.h"
9#include "src/objects-inl.h"
10
11#if V8_TARGET_ARCH_IA32
12#include "src/crankshaft/ia32/lithium-ia32.h"  // NOLINT
13#include "src/crankshaft/ia32/lithium-codegen-ia32.h"  // NOLINT
14#elif V8_TARGET_ARCH_X64
15#include "src/crankshaft/x64/lithium-x64.h"  // NOLINT
16#include "src/crankshaft/x64/lithium-codegen-x64.h"  // NOLINT
17#elif V8_TARGET_ARCH_ARM
18#include "src/crankshaft/arm/lithium-arm.h"  // NOLINT
19#include "src/crankshaft/arm/lithium-codegen-arm.h"  // NOLINT
20#elif V8_TARGET_ARCH_PPC
21#include "src/crankshaft/ppc/lithium-ppc.h"          // NOLINT
22#include "src/crankshaft/ppc/lithium-codegen-ppc.h"  // NOLINT
23#elif V8_TARGET_ARCH_MIPS
24#include "src/crankshaft/mips/lithium-mips.h"  // NOLINT
25#include "src/crankshaft/mips/lithium-codegen-mips.h"  // NOLINT
26#elif V8_TARGET_ARCH_ARM64
27#include "src/crankshaft/arm64/lithium-arm64.h"  // NOLINT
28#include "src/crankshaft/arm64/lithium-codegen-arm64.h"  // NOLINT
29#elif V8_TARGET_ARCH_MIPS64
30#include "src/crankshaft/mips64/lithium-mips64.h"  // NOLINT
31#include "src/crankshaft/mips64/lithium-codegen-mips64.h"  // NOLINT
32#elif V8_TARGET_ARCH_X87
33#include "src/crankshaft/x87/lithium-x87.h"  // NOLINT
34#include "src/crankshaft/x87/lithium-codegen-x87.h"  // NOLINT
35#elif V8_TARGET_ARCH_S390
36#include "src/crankshaft/s390/lithium-s390.h"          // NOLINT
37#include "src/crankshaft/s390/lithium-codegen-s390.h"  // NOLINT
38#else
39#error "Unknown architecture."
40#endif
41
42namespace v8 {
43namespace internal {
44
45const auto GetRegConfig = RegisterConfiguration::Crankshaft;
46
47void LOperand::PrintTo(StringStream* stream) {
48  LUnallocated* unalloc = NULL;
49  switch (kind()) {
50    case INVALID:
51      stream->Add("(0)");
52      break;
53    case UNALLOCATED:
54      unalloc = LUnallocated::cast(this);
55      stream->Add("v%d", unalloc->virtual_register());
56      if (unalloc->basic_policy() == LUnallocated::FIXED_SLOT) {
57        stream->Add("(=%dS)", unalloc->fixed_slot_index());
58        break;
59      }
60      switch (unalloc->extended_policy()) {
61        case LUnallocated::NONE:
62          break;
63        case LUnallocated::FIXED_REGISTER: {
64          int reg_index = unalloc->fixed_register_index();
65          if (reg_index < 0 || reg_index >= Register::kNumRegisters) {
66            stream->Add("(=invalid_reg#%d)", reg_index);
67          } else {
68            const char* register_name =
69                GetRegConfig()->GetGeneralRegisterName(reg_index);
70            stream->Add("(=%s)", register_name);
71          }
72          break;
73        }
74        case LUnallocated::FIXED_DOUBLE_REGISTER: {
75          int reg_index = unalloc->fixed_register_index();
76          if (reg_index < 0 || reg_index >= DoubleRegister::kMaxNumRegisters) {
77            stream->Add("(=invalid_double_reg#%d)", reg_index);
78          } else {
79            const char* double_register_name =
80                GetRegConfig()->GetDoubleRegisterName(reg_index);
81            stream->Add("(=%s)", double_register_name);
82          }
83          break;
84        }
85        case LUnallocated::MUST_HAVE_REGISTER:
86          stream->Add("(R)");
87          break;
88        case LUnallocated::MUST_HAVE_DOUBLE_REGISTER:
89          stream->Add("(D)");
90          break;
91        case LUnallocated::WRITABLE_REGISTER:
92          stream->Add("(WR)");
93          break;
94        case LUnallocated::SAME_AS_FIRST_INPUT:
95          stream->Add("(1)");
96          break;
97        case LUnallocated::ANY:
98          stream->Add("(-)");
99          break;
100      }
101      break;
102    case CONSTANT_OPERAND:
103      stream->Add("[constant:%d]", index());
104      break;
105    case STACK_SLOT:
106      stream->Add("[stack:%d]", index());
107      break;
108    case DOUBLE_STACK_SLOT:
109      stream->Add("[double_stack:%d]", index());
110      break;
111    case REGISTER: {
112      int reg_index = index();
113      if (reg_index < 0 || reg_index >= Register::kNumRegisters) {
114        stream->Add("(=invalid_reg#%d|R)", reg_index);
115      } else {
116        stream->Add("[%s|R]",
117                    GetRegConfig()->GetGeneralRegisterName(reg_index));
118      }
119      break;
120    }
121    case DOUBLE_REGISTER: {
122      int reg_index = index();
123      if (reg_index < 0 || reg_index >= DoubleRegister::kMaxNumRegisters) {
124        stream->Add("(=invalid_double_reg#%d|R)", reg_index);
125      } else {
126        stream->Add("[%s|R]", GetRegConfig()->GetDoubleRegisterName(reg_index));
127      }
128      break;
129    }
130  }
131}
132
133
134template<LOperand::Kind kOperandKind, int kNumCachedOperands>
135LSubKindOperand<kOperandKind, kNumCachedOperands>*
136LSubKindOperand<kOperandKind, kNumCachedOperands>::cache = NULL;
137
138
139template<LOperand::Kind kOperandKind, int kNumCachedOperands>
140void LSubKindOperand<kOperandKind, kNumCachedOperands>::SetUpCache() {
141  if (cache) return;
142  cache = new LSubKindOperand[kNumCachedOperands];
143  for (int i = 0; i < kNumCachedOperands; i++) {
144    cache[i].ConvertTo(kOperandKind, i);
145  }
146}
147
148
149template<LOperand::Kind kOperandKind, int kNumCachedOperands>
150void LSubKindOperand<kOperandKind, kNumCachedOperands>::TearDownCache() {
151  delete[] cache;
152  cache = NULL;
153}
154
155
156void LOperand::SetUpCaches() {
157#define LITHIUM_OPERAND_SETUP(name, type, number) L##name::SetUpCache();
158  LITHIUM_OPERAND_LIST(LITHIUM_OPERAND_SETUP)
159#undef LITHIUM_OPERAND_SETUP
160}
161
162
163void LOperand::TearDownCaches() {
164#define LITHIUM_OPERAND_TEARDOWN(name, type, number) L##name::TearDownCache();
165  LITHIUM_OPERAND_LIST(LITHIUM_OPERAND_TEARDOWN)
166#undef LITHIUM_OPERAND_TEARDOWN
167}
168
169
170bool LParallelMove::IsRedundant() const {
171  for (int i = 0; i < move_operands_.length(); ++i) {
172    if (!move_operands_[i].IsRedundant()) return false;
173  }
174  return true;
175}
176
177
178void LParallelMove::PrintDataTo(StringStream* stream) const {
179  bool first = true;
180  for (int i = 0; i < move_operands_.length(); ++i) {
181    if (!move_operands_[i].IsEliminated()) {
182      LOperand* source = move_operands_[i].source();
183      LOperand* destination = move_operands_[i].destination();
184      if (!first) stream->Add(" ");
185      first = false;
186      if (source->Equals(destination)) {
187        destination->PrintTo(stream);
188      } else {
189        destination->PrintTo(stream);
190        stream->Add(" = ");
191        source->PrintTo(stream);
192      }
193      stream->Add(";");
194    }
195  }
196}
197
198
199void LEnvironment::PrintTo(StringStream* stream) {
200  stream->Add("[id=%d|", ast_id().ToInt());
201  if (deoptimization_index() != Safepoint::kNoDeoptimizationIndex) {
202    stream->Add("deopt_id=%d|", deoptimization_index());
203  }
204  stream->Add("parameters=%d|", parameter_count());
205  stream->Add("arguments_stack_height=%d|", arguments_stack_height());
206  for (int i = 0; i < values_.length(); ++i) {
207    if (i != 0) stream->Add(";");
208    if (values_[i] == NULL) {
209      stream->Add("[hole]");
210    } else {
211      values_[i]->PrintTo(stream);
212    }
213  }
214  stream->Add("]");
215}
216
217
218void LPointerMap::RecordPointer(LOperand* op, Zone* zone) {
219  // Do not record arguments as pointers.
220  if (op->IsStackSlot() && op->index() < 0) return;
221  DCHECK(!op->IsDoubleRegister() && !op->IsDoubleStackSlot());
222  pointer_operands_.Add(op, zone);
223}
224
225
226void LPointerMap::RemovePointer(LOperand* op) {
227  // Do not record arguments as pointers.
228  if (op->IsStackSlot() && op->index() < 0) return;
229  DCHECK(!op->IsDoubleRegister() && !op->IsDoubleStackSlot());
230  for (int i = 0; i < pointer_operands_.length(); ++i) {
231    if (pointer_operands_[i]->Equals(op)) {
232      pointer_operands_.Remove(i);
233      --i;
234    }
235  }
236}
237
238
239void LPointerMap::RecordUntagged(LOperand* op, Zone* zone) {
240  // Do not record arguments as pointers.
241  if (op->IsStackSlot() && op->index() < 0) return;
242  DCHECK(!op->IsDoubleRegister() && !op->IsDoubleStackSlot());
243  untagged_operands_.Add(op, zone);
244}
245
246
247void LPointerMap::PrintTo(StringStream* stream) {
248  stream->Add("{");
249  for (int i = 0; i < pointer_operands_.length(); ++i) {
250    if (i != 0) stream->Add(";");
251    pointer_operands_[i]->PrintTo(stream);
252  }
253  stream->Add("}");
254}
255
256LChunk::LChunk(CompilationInfo* info, HGraph* graph)
257    : base_frame_slots_(info->IsStub()
258                            ? TypedFrameConstants::kFixedSlotCount
259                            : StandardFrameConstants::kFixedSlotCount),
260      current_frame_slots_(base_frame_slots_),
261      info_(info),
262      graph_(graph),
263      instructions_(32, info->zone()),
264      pointer_maps_(8, info->zone()),
265      deprecation_dependencies_(32, info->zone()),
266      stability_dependencies_(8, info->zone()) {}
267
268LLabel* LChunk::GetLabel(int block_id) const {
269  HBasicBlock* block = graph_->blocks()->at(block_id);
270  int first_instruction = block->first_instruction_index();
271  return LLabel::cast(instructions_[first_instruction]);
272}
273
274
275int LChunk::LookupDestination(int block_id) const {
276  LLabel* cur = GetLabel(block_id);
277  while (cur->replacement() != NULL) {
278    cur = cur->replacement();
279  }
280  return cur->block_id();
281}
282
283Label* LChunk::GetAssemblyLabel(int block_id) const {
284  LLabel* label = GetLabel(block_id);
285  DCHECK(!label->HasReplacement());
286  return label->label();
287}
288
289
290void LChunk::MarkEmptyBlocks() {
291  LPhase phase("L_Mark empty blocks", this);
292  for (int i = 0; i < graph()->blocks()->length(); ++i) {
293    HBasicBlock* block = graph()->blocks()->at(i);
294    int first = block->first_instruction_index();
295    int last = block->last_instruction_index();
296    LInstruction* first_instr = instructions()->at(first);
297    LInstruction* last_instr = instructions()->at(last);
298
299    LLabel* label = LLabel::cast(first_instr);
300    if (last_instr->IsGoto()) {
301      LGoto* goto_instr = LGoto::cast(last_instr);
302      if (label->IsRedundant() &&
303          !label->is_loop_header()) {
304        bool can_eliminate = true;
305        for (int i = first + 1; i < last && can_eliminate; ++i) {
306          LInstruction* cur = instructions()->at(i);
307          if (cur->IsGap()) {
308            LGap* gap = LGap::cast(cur);
309            if (!gap->IsRedundant()) {
310              can_eliminate = false;
311            }
312          } else {
313            can_eliminate = false;
314          }
315        }
316        if (can_eliminate) {
317          label->set_replacement(GetLabel(goto_instr->block_id()));
318        }
319      }
320    }
321  }
322}
323
324
325void LChunk::AddInstruction(LInstruction* instr, HBasicBlock* block) {
326  LInstructionGap* gap = new (zone()) LInstructionGap(block);
327  gap->set_hydrogen_value(instr->hydrogen_value());
328  int index = -1;
329  if (instr->IsControl()) {
330    instructions_.Add(gap, zone());
331    index = instructions_.length();
332    instructions_.Add(instr, zone());
333  } else {
334    index = instructions_.length();
335    instructions_.Add(instr, zone());
336    instructions_.Add(gap, zone());
337  }
338  if (instr->HasPointerMap()) {
339    pointer_maps_.Add(instr->pointer_map(), zone());
340    instr->pointer_map()->set_lithium_position(index);
341  }
342}
343
344LConstantOperand* LChunk::DefineConstantOperand(HConstant* constant) {
345  return LConstantOperand::Create(constant->id(), zone());
346}
347
348
349int LChunk::GetParameterStackSlot(int index) const {
350  // The receiver is at index 0, the first parameter at index 1, so we
351  // shift all parameter indexes down by the number of parameters, and
352  // make sure they end up negative so they are distinguishable from
353  // spill slots.
354  int result = index - info()->num_parameters() - 1;
355
356  DCHECK(result < 0);
357  return result;
358}
359
360
361// A parameter relative to ebp in the arguments stub.
362int LChunk::ParameterAt(int index) {
363  DCHECK(-1 <= index);  // -1 is the receiver.
364  return (1 + info()->scope()->num_parameters() - index) *
365      kPointerSize;
366}
367
368
369LGap* LChunk::GetGapAt(int index) const {
370  return LGap::cast(instructions_[index]);
371}
372
373
374bool LChunk::IsGapAt(int index) const {
375  return instructions_[index]->IsGap();
376}
377
378
379int LChunk::NearestGapPos(int index) const {
380  while (!IsGapAt(index)) index--;
381  return index;
382}
383
384
385void LChunk::AddGapMove(int index, LOperand* from, LOperand* to) {
386  GetGapAt(index)->GetOrCreateParallelMove(
387      LGap::START, zone())->AddMove(from, to, zone());
388}
389
390
391HConstant* LChunk::LookupConstant(LConstantOperand* operand) const {
392  return HConstant::cast(graph_->LookupValue(operand->index()));
393}
394
395
396Representation LChunk::LookupLiteralRepresentation(
397    LConstantOperand* operand) const {
398  return graph_->LookupValue(operand->index())->representation();
399}
400
401
402void LChunk::CommitDependencies(Handle<Code> code) const {
403  if (!code->is_optimized_code()) return;
404  HandleScope scope(isolate());
405
406  for (Handle<Map> map : deprecation_dependencies_) {
407    DCHECK(!map->is_deprecated());
408    DCHECK(map->CanBeDeprecated());
409    Map::AddDependentCode(map, DependentCode::kTransitionGroup, code);
410  }
411
412  for (Handle<Map> map : stability_dependencies_) {
413    DCHECK(map->is_stable());
414    DCHECK(map->CanTransition());
415    Map::AddDependentCode(map, DependentCode::kPrototypeCheckGroup, code);
416  }
417
418  info_->dependencies()->Commit(code);
419}
420
421
422LChunk* LChunk::NewChunk(HGraph* graph) {
423  DisallowHandleAllocation no_handles;
424  DisallowHeapAllocation no_gc;
425  graph->DisallowAddingNewValues();
426  int values = graph->GetMaximumValueID();
427  CompilationInfo* info = graph->info();
428  if (values > LUnallocated::kMaxVirtualRegisters) {
429    info->AbortOptimization(kNotEnoughVirtualRegistersForValues);
430    return NULL;
431  }
432  LAllocator allocator(values, graph);
433  LChunkBuilder builder(info, graph, &allocator);
434  LChunk* chunk = builder.Build();
435  if (chunk == NULL) return NULL;
436
437  if (!allocator.Allocate(chunk)) {
438    info->AbortOptimization(kNotEnoughVirtualRegistersRegalloc);
439    return NULL;
440  }
441
442  chunk->set_allocated_double_registers(
443      allocator.assigned_double_registers());
444
445  return chunk;
446}
447
448
449Handle<Code> LChunk::Codegen() {
450  MacroAssembler assembler(info()->isolate(), NULL, 0,
451                           CodeObjectRequired::kYes);
452  // Code serializer only takes unoptimized code.
453  DCHECK(!info()->will_serialize());
454  LCodeGen generator(this, &assembler, info());
455
456  MarkEmptyBlocks();
457
458  if (generator.GenerateCode()) {
459    generator.CheckEnvironmentUsage();
460    CodeGenerator::MakeCodePrologue(info(), "optimized");
461    Handle<Code> code = CodeGenerator::MakeCodeEpilogue(
462        &assembler, nullptr, info(), assembler.CodeObject());
463    generator.FinishCode(code);
464    CommitDependencies(code);
465    Handle<ByteArray> source_positions =
466        generator.source_position_table_builder()->ToSourcePositionTable(
467            info()->isolate(), Handle<AbstractCode>::cast(code));
468    code->set_source_position_table(*source_positions);
469    code->set_is_crankshafted(true);
470
471    CodeGenerator::PrintCode(code, info());
472    return code;
473  }
474  assembler.AbortedCodeGeneration();
475  return Handle<Code>::null();
476}
477
478
479void LChunk::set_allocated_double_registers(BitVector* allocated_registers) {
480  allocated_double_registers_ = allocated_registers;
481  BitVector* doubles = allocated_double_registers();
482  BitVector::Iterator iterator(doubles);
483  while (!iterator.Done()) {
484    if (info()->saves_caller_doubles()) {
485      if (kDoubleSize == kPointerSize * 2) {
486        current_frame_slots_ += 2;
487      } else {
488        current_frame_slots_++;
489      }
490    }
491    iterator.Advance();
492  }
493}
494
495
496void LChunkBuilderBase::Abort(BailoutReason reason) {
497  info()->AbortOptimization(reason);
498  status_ = ABORTED;
499}
500
501
502void LChunkBuilderBase::Retry(BailoutReason reason) {
503  info()->RetryOptimization(reason);
504  status_ = ABORTED;
505}
506
507void LChunkBuilderBase::CreateLazyBailoutForCall(HBasicBlock* current_block,
508                                                 LInstruction* instr,
509                                                 HInstruction* hydrogen_val) {
510  if (!instr->IsCall()) return;
511
512  HEnvironment* hydrogen_env = current_block->last_environment();
513  HValue* hydrogen_value_for_lazy_bailout = hydrogen_val;
514  DCHECK_NOT_NULL(hydrogen_env);
515  if (instr->IsSyntacticTailCall()) {
516    // If it was a syntactic tail call we need to drop the current frame and
517    // all the frames on top of it that are either an arguments adaptor frame
518    // or a tail caller frame.
519    hydrogen_env = hydrogen_env->outer();
520    while (hydrogen_env != nullptr &&
521           (hydrogen_env->frame_type() == ARGUMENTS_ADAPTOR ||
522            hydrogen_env->frame_type() == TAIL_CALLER_FUNCTION)) {
523      hydrogen_env = hydrogen_env->outer();
524    }
525    if (hydrogen_env != nullptr) {
526      if (hydrogen_env->frame_type() == JS_FUNCTION) {
527        // In case an outer frame is a function frame we have to replay
528        // environment manually because
529        // 1) it does not contain a result of inlined function yet,
530        // 2) we can't find the proper simulate that corresponds to the point
531        //    after inlined call to do a ReplayEnvironment() on.
532        // So we push return value on top of outer environment.
533        // As for JS_GETTER/JS_SETTER/JS_CONSTRUCT nothing has to be done here,
534        // the deoptimizer ensures that the result of the callee is correctly
535        // propagated to result register during deoptimization.
536        hydrogen_env = hydrogen_env->Copy();
537        hydrogen_env->Push(hydrogen_val);
538      }
539    } else {
540      // Although we don't need this lazy bailout for normal execution
541      // (because when we tail call from the outermost function we should pop
542      // its frame) we still need it when debugger is on.
543      hydrogen_env = current_block->last_environment();
544    }
545  } else {
546    if (hydrogen_val->HasObservableSideEffects()) {
547      HSimulate* sim = HSimulate::cast(hydrogen_val->next());
548      sim->ReplayEnvironment(hydrogen_env);
549      hydrogen_value_for_lazy_bailout = sim;
550    }
551  }
552  LInstruction* bailout = LChunkBuilderBase::AssignEnvironment(
553      new (zone()) LLazyBailout(), hydrogen_env);
554  bailout->set_hydrogen_value(hydrogen_value_for_lazy_bailout);
555  chunk_->AddInstruction(bailout, current_block);
556}
557
558LInstruction* LChunkBuilderBase::AssignEnvironment(LInstruction* instr,
559                                                   HEnvironment* hydrogen_env) {
560  int argument_index_accumulator = 0;
561  ZoneList<HValue*> objects_to_materialize(0, zone());
562  DCHECK_NE(TAIL_CALLER_FUNCTION, hydrogen_env->frame_type());
563  instr->set_environment(CreateEnvironment(
564      hydrogen_env, &argument_index_accumulator, &objects_to_materialize));
565  return instr;
566}
567
568LEnvironment* LChunkBuilderBase::CreateEnvironment(
569    HEnvironment* hydrogen_env, int* argument_index_accumulator,
570    ZoneList<HValue*>* objects_to_materialize) {
571  if (hydrogen_env == NULL) return NULL;
572
573  BailoutId ast_id = hydrogen_env->ast_id();
574  DCHECK(!ast_id.IsNone() ||
575         (hydrogen_env->frame_type() != JS_FUNCTION &&
576          hydrogen_env->frame_type() != TAIL_CALLER_FUNCTION));
577
578  if (hydrogen_env->frame_type() == TAIL_CALLER_FUNCTION) {
579    // Skip potential outer arguments adaptor frame.
580    HEnvironment* outer_hydrogen_env = hydrogen_env->outer();
581    if (outer_hydrogen_env != nullptr &&
582        outer_hydrogen_env->frame_type() == ARGUMENTS_ADAPTOR) {
583      outer_hydrogen_env = outer_hydrogen_env->outer();
584    }
585    LEnvironment* outer = CreateEnvironment(
586        outer_hydrogen_env, argument_index_accumulator, objects_to_materialize);
587    return new (zone())
588        LEnvironment(hydrogen_env->closure(), hydrogen_env->frame_type(),
589                     ast_id, 0, 0, 0, outer, hydrogen_env->entry(), zone());
590  }
591
592  LEnvironment* outer =
593      CreateEnvironment(hydrogen_env->outer(), argument_index_accumulator,
594                        objects_to_materialize);
595
596  int omitted_count = (hydrogen_env->frame_type() == JS_FUNCTION)
597                          ? 0
598                          : hydrogen_env->specials_count();
599
600  int value_count = hydrogen_env->length() - omitted_count;
601  LEnvironment* result =
602      new(zone()) LEnvironment(hydrogen_env->closure(),
603                               hydrogen_env->frame_type(),
604                               ast_id,
605                               hydrogen_env->parameter_count(),
606                               argument_count_,
607                               value_count,
608                               outer,
609                               hydrogen_env->entry(),
610                               zone());
611  int argument_index = *argument_index_accumulator;
612
613  // Store the environment description into the environment
614  // (with holes for nested objects)
615  for (int i = 0; i < hydrogen_env->length(); ++i) {
616    if (hydrogen_env->is_special_index(i) &&
617        hydrogen_env->frame_type() != JS_FUNCTION) {
618      continue;
619    }
620    LOperand* op;
621    HValue* value = hydrogen_env->values()->at(i);
622    CHECK(!value->IsPushArguments());  // Do not deopt outgoing arguments
623    if (value->IsArgumentsObject() || value->IsCapturedObject()) {
624      op = LEnvironment::materialization_marker();
625    } else {
626      op = UseAny(value);
627    }
628    result->AddValue(op,
629                     value->representation(),
630                     value->CheckFlag(HInstruction::kUint32));
631  }
632
633  // Recursively store the nested objects into the environment
634  for (int i = 0; i < hydrogen_env->length(); ++i) {
635    if (hydrogen_env->is_special_index(i)) continue;
636
637    HValue* value = hydrogen_env->values()->at(i);
638    if (value->IsArgumentsObject() || value->IsCapturedObject()) {
639      AddObjectToMaterialize(value, objects_to_materialize, result);
640    }
641  }
642
643  if (hydrogen_env->frame_type() == JS_FUNCTION) {
644    *argument_index_accumulator = argument_index;
645  }
646
647  return result;
648}
649
650
651// Add an object to the supplied environment and object materialization list.
652//
653// Notes:
654//
655// We are building three lists here:
656//
657// 1. In the result->object_mapping_ list (added to by the
658//    LEnvironment::Add*Object methods), we store the lengths (number
659//    of fields) of the captured objects in depth-first traversal order, or
660//    in case of duplicated objects, we store the index to the duplicate object
661//    (with a tag to differentiate between captured and duplicated objects).
662//
663// 2. The object fields are stored in the result->values_ list
664//    (added to by the LEnvironment.AddValue method) sequentially as lists
665//    of fields with holes for nested objects (the holes will be expanded
666//    later by LCodegen::AddToTranslation according to the
667//    LEnvironment.object_mapping_ list).
668//
669// 3. The auxiliary objects_to_materialize array stores the hydrogen values
670//    in the same order as result->object_mapping_ list. This is used
671//    to detect duplicate values and calculate the corresponding object index.
672void LChunkBuilderBase::AddObjectToMaterialize(HValue* value,
673    ZoneList<HValue*>* objects_to_materialize, LEnvironment* result) {
674  int object_index = objects_to_materialize->length();
675  // Store the hydrogen value into the de-duplication array
676  objects_to_materialize->Add(value, zone());
677  // Find out whether we are storing a duplicated value
678  int previously_materialized_object = -1;
679  for (int prev = 0; prev < object_index; ++prev) {
680    if (objects_to_materialize->at(prev) == value) {
681      previously_materialized_object = prev;
682      break;
683    }
684  }
685  // Store the captured object length (or duplicated object index)
686  // into the environment. For duplicated objects, we stop here.
687  int length = value->OperandCount();
688  bool is_arguments = value->IsArgumentsObject();
689  if (previously_materialized_object >= 0) {
690    result->AddDuplicateObject(previously_materialized_object);
691    return;
692  } else {
693    result->AddNewObject(is_arguments ? length - 1 : length, is_arguments);
694  }
695  // Store the captured object's fields into the environment
696  for (int i = is_arguments ? 1 : 0; i < length; ++i) {
697    LOperand* op;
698    HValue* arg_value = value->OperandAt(i);
699    if (arg_value->IsArgumentsObject() || arg_value->IsCapturedObject()) {
700      // Insert a hole for nested objects
701      op = LEnvironment::materialization_marker();
702    } else {
703      DCHECK(!arg_value->IsPushArguments());
704      // For ordinary values, tell the register allocator we need the value
705      // to be alive here
706      op = UseAny(arg_value);
707    }
708    result->AddValue(op,
709                     arg_value->representation(),
710                     arg_value->CheckFlag(HInstruction::kUint32));
711  }
712  // Recursively store all the nested captured objects into the environment
713  for (int i = is_arguments ? 1 : 0; i < length; ++i) {
714    HValue* arg_value = value->OperandAt(i);
715    if (arg_value->IsArgumentsObject() || arg_value->IsCapturedObject()) {
716      AddObjectToMaterialize(arg_value, objects_to_materialize, result);
717    }
718  }
719}
720
721
722LPhase::~LPhase() {
723  if (ShouldProduceTraceOutput()) {
724    isolate()->GetHTracer()->TraceLithium(name(), chunk_);
725  }
726}
727
728
729}  // namespace internal
730}  // namespace v8
731