Merge 6800:7180 from the bleeding edge branch to the experimental/gc branch.

src/hydrogen.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 74 matching lines @@
 void HBasicBlock::AddPhi(HPhi* phi) {
   ASSERT(!IsStartBlock());
   phis_.Add(phi);
   phi->SetBlock(this);
 }
 
 
 void HBasicBlock::RemovePhi(HPhi* phi) {
   ASSERT(phi->block() == this);
   ASSERT(phis_.Contains(phi));
-  ASSERT(phi->HasNoUses());
+  ASSERT(phi->HasNoUses() || !phi->is_live());
   phi->ClearOperands();
   phis_.RemoveElement(phi);
   phi->SetBlock(NULL);
 }
 
 
 void HBasicBlock::AddInstruction(HInstruction* instr) {
   ASSERT(!IsStartBlock() || !IsFinished());
   ASSERT(!instr->IsLinked());
   ASSERT(!IsFinished());
@@ skipping 37 matching lines @@
   if (end->FirstSuccessor() != NULL) {
     end->FirstSuccessor()->RegisterPredecessor(this);
     if (end->SecondSuccessor() != NULL) {
       end->SecondSuccessor()->RegisterPredecessor(this);
     }
   }
 }
 
 
 void HBasicBlock::Goto(HBasicBlock* block, bool include_stack_check) {
+  if (block->IsInlineReturnTarget()) {
+    AddInstruction(new HLeaveInlined);
+    last_environment_ = last_environment()->outer();
+  }
   AddSimulate(AstNode::kNoNumber);
   HGoto* instr = new HGoto(block);
   instr->set_include_stack_check(include_stack_check);
   Finish(instr);
 }
 
 
+void HBasicBlock::AddLeaveInlined(HValue* return_value, HBasicBlock* target) {
+  ASSERT(target->IsInlineReturnTarget());
+  ASSERT(return_value != NULL);
+  AddInstruction(new HLeaveInlined);
+  last_environment_ = last_environment()->outer();
+  last_environment()->Push(return_value);
+  AddSimulate(AstNode::kNoNumber);
+  HGoto* instr = new HGoto(target);
+  Finish(instr);
+}
+
+
 void HBasicBlock::SetInitialEnvironment(HEnvironment* env) {
   ASSERT(!HasEnvironment());
   ASSERT(first() == NULL);
   UpdateEnvironment(env);
 }
 
 
 void HBasicBlock::SetJoinId(int id) {
   int length = predecessors_.length();
   ASSERT(length > 0);
@@ skipping 109 matching lines @@
   UNREACHABLE();
   return -1;
 }
 
 
 #ifdef DEBUG
 void HBasicBlock::Verify() {
   // Check that every block is finished.
   ASSERT(IsFinished());
   ASSERT(block_id() >= 0);
+
+  // Check that the incoming edges are in edge split form.
+  if (predecessors_.length() > 1) {
+    for (int i = 0; i < predecessors_.length(); ++i) {
+      ASSERT(predecessors_[i]->end()->SecondSuccessor() == NULL);
+    }
+  }
 }
 #endif
 
 
 void HLoopInformation::RegisterBackEdge(HBasicBlock* block) {
   this->back_edges_.Add(block);
   AddBlock(block);
 }
 
 
@@ skipping 176 matching lines @@
 HConstant* HGraph::GetConstantTrue() {
   return GetConstant(&constant_true_, Heap::true_value());
 }
 
 
 HConstant* HGraph::GetConstantFalse() {
   return GetConstant(&constant_false_, Heap::false_value());
 }
 
 
-void HSubgraph::AppendOptional(HSubgraph* graph,
-                               bool on_true_branch,
-                               HValue* value) {
-  ASSERT(HasExit() && graph->HasExit());
-  HBasicBlock* other_block = graph_->CreateBasicBlock();
-  HBasicBlock* join_block = graph_->CreateBasicBlock();
-
-  HTest* test = on_true_branch
-      ? new HTest(value, graph->entry_block(), other_block)
-      : new HTest(value, other_block, graph->entry_block());
-  exit_block_->Finish(test);
-  other_block->Goto(join_block);
-  graph->exit_block()->Goto(join_block);
-  exit_block_ = join_block;
-}
-
-
-void HSubgraph::AppendJoin(HSubgraph* then_graph,
-                           HSubgraph* else_graph,
-                           AstNode* node) {
-  if (then_graph->HasExit() && else_graph->HasExit()) {
-    // We need to merge, create new merge block.
+HBasicBlock* HGraphBuilder::CreateJoin(HBasicBlock* first,
+                                       HBasicBlock* second,
+                                       int join_id) {
+  if (first == NULL) {
+    return second;
+  } else if (second == NULL) {
+    return first;
+  } else {
     HBasicBlock* join_block = graph_->CreateBasicBlock();
-    then_graph->exit_block()->Goto(join_block);
-    else_graph->exit_block()->Goto(join_block);
-    join_block->SetJoinId(node->id());
-    exit_block_ = join_block;
-  } else if (then_graph->HasExit()) {
-    exit_block_ = then_graph->exit_block_;
-  } else if (else_graph->HasExit()) {
-    exit_block_ = else_graph->exit_block_;
-  } else {
-    exit_block_ = NULL;
+    first->Goto(join_block);
+    second->Goto(join_block);
+    join_block->SetJoinId(join_id);
+    return join_block;
   }
 }
 
 
-void HSubgraph::ResolveContinue(IterationStatement* statement) {
-  HBasicBlock* continue_block = BundleContinue(statement);
+HBasicBlock* HGraphBuilder::JoinContinue(IterationStatement* statement,
+                                         HBasicBlock* exit_block,
+                                         HBasicBlock* continue_block) {
   if (continue_block != NULL) {
-    exit_block_ = JoinBlocks(exit_block(),
-                             continue_block,
-                             statement->ContinueId());
+    if (exit_block != NULL) exit_block->Goto(continue_block);
+    continue_block->SetJoinId(statement->ContinueId());
+    return continue_block;
   }
+  return exit_block;
 }
 
 
-HBasicBlock* HSubgraph::BundleBreak(BreakableStatement* statement) {
-  return BundleBreakContinue(statement, false, statement->ExitId());
+HBasicBlock* HGraphBuilder::CreateLoop(IterationStatement* statement,
+                                       HBasicBlock* loop_entry,
+                                       HBasicBlock* body_exit,
+                                       HBasicBlock* loop_successor,
+                                       HBasicBlock* break_block) {
+  if (body_exit != NULL) body_exit->Goto(loop_entry, true);
+  loop_entry->PostProcessLoopHeader(statement);
+  if (break_block != NULL) {
+    if (loop_successor != NULL) loop_successor->Goto(break_block);
+    break_block->SetJoinId(statement->ExitId());
+    return break_block;
+  }
+  return loop_successor;
 }
 
 
-HBasicBlock* HSubgraph::BundleContinue(IterationStatement* statement) {
-  return BundleBreakContinue(statement, true, statement->ContinueId());
-}
-
-
-HBasicBlock* HSubgraph::BundleBreakContinue(BreakableStatement* statement,
-                                            bool is_continue,
-                                            int join_id) {
-  HBasicBlock* result = NULL;
-  const ZoneList<BreakContinueInfo*>* infos = break_continue_info();
-  for (int i = 0; i < infos->length(); ++i) {
-    BreakContinueInfo* info = infos->at(i);
-    if (info->is_continue() == is_continue &&
-        info->target() == statement &&
-        !info->IsResolved()) {
-      if (result == NULL) {
-        result = graph_->CreateBasicBlock();
-      }
-      info->block()->Goto(result);
-      info->Resolve();
-    }
-  }
-
-  if (result != NULL) result->SetJoinId(join_id);
-
-  return result;
-}
-
-
-HBasicBlock* HSubgraph::JoinBlocks(HBasicBlock* a, HBasicBlock* b, int id) {
-  if (a == NULL) return b;
-  if (b == NULL) return a;
-  HBasicBlock* target = graph_->CreateBasicBlock();
-  a->Goto(target);
-  b->Goto(target);
-  target->SetJoinId(id);
-  return target;
-}
-
-
-void HSubgraph::AppendEndless(HSubgraph* body, IterationStatement* statement) {
-  ConnectExitTo(body->entry_block());
-  body->ResolveContinue(statement);
-  body->ConnectExitTo(body->entry_block(), true);
-  exit_block_ = body->BundleBreak(statement);
-  body->entry_block()->PostProcessLoopHeader(statement);
-}
-
-
-void HSubgraph::AppendDoWhile(HSubgraph* body,
-                              IterationStatement* statement,
-                              HSubgraph* go_back,
-                              HSubgraph* exit) {
-  ConnectExitTo(body->entry_block());
-  go_back->ConnectExitTo(body->entry_block(), true);
-
-  HBasicBlock* break_block = body->BundleBreak(statement);
-  exit_block_ =
-      JoinBlocks(exit->exit_block(), break_block, statement->ExitId());
-  body->entry_block()->PostProcessLoopHeader(statement);
-}
-
-
-void HSubgraph::AppendWhile(HSubgraph* condition,
-                            HSubgraph* body,
-                            IterationStatement* statement,
-                            HSubgraph* continue_subgraph,
-                            HSubgraph* exit) {
-  ConnectExitTo(condition->entry_block());
-
-  HBasicBlock* break_block = body->BundleBreak(statement);
-  exit_block_ =
-      JoinBlocks(exit->exit_block(), break_block, statement->ExitId());
-
-  if (continue_subgraph != NULL) {
-    body->ConnectExitTo(continue_subgraph->entry_block(), true);
-    continue_subgraph->entry_block()->SetJoinId(statement->EntryId());
-    exit_block_ = JoinBlocks(exit_block_,
-                             continue_subgraph->exit_block(),
-                             statement->ExitId());
-  } else {
-    body->ConnectExitTo(condition->entry_block(), true);
-  }
-  condition->entry_block()->PostProcessLoopHeader(statement);
-}
-
-
-void HSubgraph::Append(HSubgraph* next, BreakableStatement* stmt) {
-  exit_block_->Goto(next->entry_block());
-  exit_block_ = next->exit_block_;
-
-  if (stmt != NULL) {
-    next->entry_block()->SetJoinId(stmt->EntryId());
-    HBasicBlock* break_block = next->BundleBreak(stmt);
-    exit_block_ = JoinBlocks(exit_block(), break_block, stmt->ExitId());
-  }
-}
-
-
-void HSubgraph::FinishExit(HControlInstruction* instruction) {
-  ASSERT(HasExit());
-  exit_block_->Finish(instruction);
-  exit_block_->ClearEnvironment();
-  exit_block_ = NULL;
-}
-
-
-void HSubgraph::FinishBreakContinue(BreakableStatement* target,
-                                    bool is_continue) {
-  ASSERT(!exit_block_->IsFinished());
-  BreakContinueInfo* info = new BreakContinueInfo(target, exit_block_,
-                                                  is_continue);
-  break_continue_info_.Add(info);
-  exit_block_ = NULL;
+void HBasicBlock::FinishExit(HControlInstruction* instruction) {
+  Finish(instruction);
+  ClearEnvironment();
 }
 
 
 HGraph::HGraph(CompilationInfo* info)
-    : HSubgraph(this),
-      next_block_id_(0),
-      info_(info),
+    : next_block_id_(0),
+      entry_block_(NULL),
       blocks_(8),
       values_(16),
       phi_list_(NULL) {
   start_environment_ = new HEnvironment(NULL, info->scope(), info->closure());
   start_environment_->set_ast_id(info->function()->id());
+  entry_block_ = CreateBasicBlock();
+  entry_block_->SetInitialEnvironment(start_environment_);
 }
 
 
-bool HGraph::AllowCodeMotion() const {
-  return info()->shared_info()->opt_count() + 1 < Compiler::kDefaultMaxOptCount;
-}
-
-
-Handle<Code> HGraph::Compile() {
+Handle<Code> HGraph::Compile(CompilationInfo* info) {
   int values = GetMaximumValueID();
   if (values > LAllocator::max_initial_value_ids()) {
     if (FLAG_trace_bailout) PrintF("Function is too big\n");
     return Handle<Code>::null();
   }
 
   LAllocator allocator(values, this);
-  LChunkBuilder builder(this, &allocator);
+  LChunkBuilder builder(info, this, &allocator);
   LChunk* chunk = builder.Build();
   if (chunk == NULL) return Handle<Code>::null();
 
   if (!FLAG_alloc_lithium) return Handle<Code>::null();
 
   allocator.Allocate(chunk);
 
   if (!FLAG_use_lithium) return Handle<Code>::null();
 
   MacroAssembler assembler(NULL, 0);
-  LCodeGen generator(chunk, &assembler, info());
+  LCodeGen generator(chunk, &assembler, info);
 
   if (FLAG_eliminate_empty_blocks) {
     chunk->MarkEmptyBlocks();
   }
 
   if (generator.GenerateCode()) {
     if (FLAG_trace_codegen) {
       PrintF("Crankshaft Compiler - ");
     }
-    CodeGenerator::MakeCodePrologue(info());
+    CodeGenerator::MakeCodePrologue(info);
     Code::Flags flags =
         Code::ComputeFlags(Code::OPTIMIZED_FUNCTION, NOT_IN_LOOP);
     Handle<Code> code =
-        CodeGenerator::MakeCodeEpilogue(&assembler, flags, info());
+        CodeGenerator::MakeCodeEpilogue(&assembler, flags, info);
     generator.FinishCode(code);
-    CodeGenerator::PrintCode(code, info());
+    CodeGenerator::PrintCode(code, info);
     return code;
   }
   return Handle<Code>::null();
 }
 
 
 HBasicBlock* HGraph::CreateBasicBlock() {
   HBasicBlock* result = new HBasicBlock(this);
   blocks_.Add(result);
   return result;
 }
 
 
 void HGraph::Canonicalize() {
+  if (!FLAG_use_canonicalizing) return;
   HPhase phase("Canonicalize", this);
-  if (FLAG_use_canonicalizing) {
-    for (int i = 0; i < blocks()->length(); ++i) {
-      HBasicBlock* b = blocks()->at(i);
-      for (HInstruction* insn = b->first(); insn != NULL; insn = insn->next()) {
-        HValue* value = insn->Canonicalize();
-        if (value != insn) {
-          if (value != NULL) {
-            insn->ReplaceAndDelete(value);
-          } else {
-            insn->Delete();
-          }
-        }
-      }
+  for (int i = 0; i < blocks()->length(); ++i) {
+    HInstruction* instr = blocks()->at(i)->first();
+    while (instr != NULL) {
+      HValue* value = instr->Canonicalize();
+      if (value != instr) instr->ReplaceAndDelete(value);
+      instr = instr->next();
     }
   }
 }
 
 
 void HGraph::OrderBlocks() {
   HPhase phase("Block ordering");
   BitVector visited(blocks_.length());
 
   ZoneList<HBasicBlock*> reverse_result(8);
   HBasicBlock* start = blocks_[0];
   Postorder(start, &visited, &reverse_result, NULL);
 
-  blocks_.Clear();
+  blocks_.Rewind(0);
   int index = 0;
   for (int i = reverse_result.length() - 1; i >= 0; --i) {
     HBasicBlock* b = reverse_result[i];
     blocks_.Add(b);
     b->set_block_id(index++);
   }
 }
 
 
 void HGraph::PostorderLoopBlocks(HLoopInformation* loop,
@@ skipping 44 matching lines @@
     } else {
       for (int j = 0; j < blocks_[i]->predecessors()->length(); ++j) {
         blocks_[i]->AssignCommonDominator(blocks_[i]->predecessors()->at(j));
       }
     }
   }
 }
 
 
 void HGraph::EliminateRedundantPhis() {
-  HPhase phase("Phi elimination", this);
-  ZoneList<HValue*> uses_to_replace(2);
+  HPhase phase("Redundant phi elimination", this);
 
   // Worklist of phis that can potentially be eliminated. Initialized
   // with all phi nodes. When elimination of a phi node modifies
   // another phi node the modified phi node is added to the worklist.
   ZoneList<HPhi*> worklist(blocks_.length());
   for (int i = 0; i < blocks_.length(); ++i) {
     worklist.AddAll(*blocks_[i]->phis());
   }
 
   while (!worklist.is_empty()) {
     HPhi* phi = worklist.RemoveLast();
     HBasicBlock* block = phi->block();
 
     // Skip phi node if it was already replaced.
     if (block == NULL) continue;
 
     // Get replacement value if phi is redundant.
     HValue* value = phi->GetRedundantReplacement();
 
     if (value != NULL) {
       // Iterate through uses finding the ones that should be
       // replaced.
-      const ZoneList<HValue*>* uses = phi->uses();
-      for (int i = 0; i < uses->length(); ++i) {
-        HValue* use = uses->at(i);
-        if (!use->block()->IsStartBlock()) {
-          uses_to_replace.Add(use);
+      ZoneList<HValue*>* uses = phi->uses();
+      while (!uses->is_empty()) {
+        HValue* use = uses->RemoveLast();
+        if (use != NULL) {
+          phi->ReplaceAtUse(use, value);
+          if (use->IsPhi()) worklist.Add(HPhi::cast(use));
         }
       }
-      // Replace the uses and add phis modified to the work list.
-      for (int i = 0; i < uses_to_replace.length(); ++i) {
-        HValue* use = uses_to_replace[i];
-        phi->ReplaceAtUse(use, value);
-        if (use->IsPhi()) worklist.Add(HPhi::cast(use));
-      }
-      uses_to_replace.Rewind(0);
       block->RemovePhi(phi);
-    } else if (FLAG_eliminate_dead_phis && phi->HasNoUses() &&
-               !phi->IsReceiver()) {
+    }
+  }
+}
+
+
+void HGraph::EliminateUnreachablePhis() {
+  HPhase phase("Unreachable phi elimination", this);
+
+  // Initialize worklist.
+  ZoneList<HPhi*> phi_list(blocks_.length());
+  ZoneList<HPhi*> worklist(blocks_.length());
+  for (int i = 0; i < blocks_.length(); ++i) {
+    for (int j = 0; j < blocks_[i]->phis()->length(); j++) {
+      HPhi* phi = blocks_[i]->phis()->at(j);
+      phi_list.Add(phi);
       // We can't eliminate phis in the receiver position in the environment
       // because in case of throwing an error we need this value to
       // construct a stack trace.
+      if (phi->HasRealUses() || phi->IsReceiver())  {
+        phi->set_is_live(true);
+        worklist.Add(phi);
+      }
+    }
+  }
+
+  // Iteratively mark live phis.
+  while (!worklist.is_empty()) {
+    HPhi* phi = worklist.RemoveLast();
+    for (int i = 0; i < phi->OperandCount(); i++) {
+      HValue* operand = phi->OperandAt(i);
+      if (operand->IsPhi() && !HPhi::cast(operand)->is_live()) {
+        HPhi::cast(operand)->set_is_live(true);
+        worklist.Add(HPhi::cast(operand));
+      }
+    }
+  }
+
+  // Remove unreachable phis.
+  for (int i = 0; i < phi_list.length(); i++) {
+    HPhi* phi = phi_list[i];
+    if (!phi->is_live()) {
+      HBasicBlock* block = phi->block();
       block->RemovePhi(phi);
       block->RecordDeletedPhi(phi->merged_index());
     }
   }
 }
 
 
 bool HGraph::CollectPhis() {
-  const ZoneList<HBasicBlock*>* blocks = graph_->blocks();
-  phi_list_ = new ZoneList<HPhi*>(blocks->length());
-  for (int i = 0; i < blocks->length(); ++i) {
-    for (int j = 0; j < blocks->at(i)->phis()->length(); j++) {
-      HPhi* phi = blocks->at(i)->phis()->at(j);
+  int block_count = blocks_.length();
+  phi_list_ = new ZoneList<HPhi*>(block_count);
+  for (int i = 0; i < block_count; ++i) {
+    for (int j = 0; j < blocks_[i]->phis()->length(); ++j) {
+      HPhi* phi = blocks_[i]->phis()->at(j);
       phi_list_->Add(phi);
       // We don't support phi uses of arguments for now.
       if (phi->CheckFlag(HValue::kIsArguments)) return false;
     }
   }
   return true;
 }
 
 
 void HGraph::InferTypes(ZoneList<HValue*>* worklist) {
@@ skipping 88 matching lines @@
   }
 
   RollBackTo(last_changed_range);
 }
 
 
 void HRangeAnalysis::InferControlFlowRange(HTest* test, HBasicBlock* dest) {
   ASSERT((test->FirstSuccessor() == dest) == (test->SecondSuccessor() != dest));
   if (test->value()->IsCompare()) {
     HCompare* compare = HCompare::cast(test->value());
-    Token::Value op = compare->token();
-    if (test->SecondSuccessor() == dest) {
-      op = Token::NegateCompareOp(op);
+    if (compare->GetInputRepresentation().IsInteger32()) {
+      Token::Value op = compare->token();
+      if (test->SecondSuccessor() == dest) {
+        op = Token::NegateCompareOp(op);
+      }
+      Token::Value inverted_op = Token::InvertCompareOp(op);
+      InferControlFlowRange(op, compare->left(), compare->right());
+      InferControlFlowRange(inverted_op, compare->right(), compare->left());
     }
-    Token::Value inverted_op = Token::InvertCompareOp(op);
-    InferControlFlowRange(op, compare->left(), compare->right());
-    InferControlFlowRange(inverted_op, compare->right(), compare->left());
   }
 }
 
 
 // We know that value [op] other. Use this information to update the range on
 // value.
 void HRangeAnalysis::InferControlFlowRange(Token::Value op,
                                            HValue* value,
                                            HValue* other) {
-  Range* range = other->range();
-  if (range == NULL) range = new Range();
+  Range temp_range;
+  Range* range = other->range() != NULL ? other->range() : &temp_range;
   Range* new_range = NULL;
 
   TraceRange("Control flow range infer %d %s %d\n",
              value->id(),
              Token::Name(op),
              other->id());
 
   if (op == Token::EQ || op == Token::EQ_STRICT) {
     // The same range has to apply for value.
     new_range = range->Copy();
@@ skipping 287 matching lines @@
       HGoto::cast(instr)->set_include_stack_check(false);
       return;
     }
     instr = instr->next();
   }
 }
 
 
 class HGlobalValueNumberer BASE_EMBEDDED {
  public:
-  explicit HGlobalValueNumberer(HGraph* graph)
+  explicit HGlobalValueNumberer(HGraph* graph, CompilationInfo* info)
       : graph_(graph),
+        info_(info),
         block_side_effects_(graph_->blocks()->length()),
         loop_side_effects_(graph_->blocks()->length()) {
     ASSERT(Heap::allow_allocation(false));
     block_side_effects_.AddBlock(0, graph_->blocks()->length());
     loop_side_effects_.AddBlock(0, graph_->blocks()->length());
   }
   ~HGlobalValueNumberer() {
     ASSERT(!Heap::allow_allocation(true));
   }
 
   void Analyze();
 
  private:
   void AnalyzeBlock(HBasicBlock* block, HValueMap* map);
   void ComputeBlockSideEffects();
   void LoopInvariantCodeMotion();
   void ProcessLoopBlock(HBasicBlock* block,
                         HBasicBlock* before_loop,
                         int loop_kills);
+  bool AllowCodeMotion();
   bool ShouldMove(HInstruction* instr, HBasicBlock* loop_header);
 
+  HGraph* graph() { return graph_; }
+  CompilationInfo* info() { return info_; }
+
   HGraph* graph_;
+  CompilationInfo* info_;
 
   // A map of block IDs to their side effects.
   ZoneList<int> block_side_effects_;
 
   // A map of loop header block IDs to their loop's side effects.
   ZoneList<int> loop_side_effects_;
 };
 
 
 void HGlobalValueNumberer::Analyze() {
@@ skipping 80 matching lines @@
         // Move the instruction out of the loop.
         instr->Unlink();
         instr->InsertBefore(pre_header->end());
       }
     }
     instr = next;
   }
 }
 
 
+bool HGlobalValueNumberer::AllowCodeMotion() {
+  return info()->shared_info()->opt_count() + 1 < Compiler::kDefaultMaxOptCount;
+}
+
+
 bool HGlobalValueNumberer::ShouldMove(HInstruction* instr,
                                       HBasicBlock* loop_header) {
   // If we've disabled code motion, don't move any instructions.
-  if (!graph_->AllowCodeMotion()) return false;
+  if (!AllowCodeMotion()) return false;
 
   // If --aggressive-loop-invariant-motion, move everything except change
   // instructions.
   if (FLAG_aggressive_loop_invariant_motion && !instr->IsChange()) {
     return true;
   }
 
   // Otherwise only move instructions that postdominate the loop header
   // (i.e. are always executed inside the loop). This is to avoid
   // unnecessary deoptimizations assuming the loop is executed at least
@@ skipping 39 matching lines @@
       TraceGVN("Instruction %d kills\n", instr->id());
     } else if (instr->CheckFlag(HValue::kUseGVN)) {
       HValue* other = map->Lookup(instr);
       if (other != NULL) {
         ASSERT(instr->Equals(other) && other->Equals(instr));
         TraceGVN("Replacing value %d (%s) with value %d (%s)\n",
                  instr->id(),
                  instr->Mnemonic(),
                  other->id(),
                  other->Mnemonic());
-        instr->ReplaceValue(other);
-        instr->Delete();
+        instr->ReplaceAndDelete(other);
       } else {
         map->Add(instr);
       }
     }
     instr = next;
   }
 
   // Recursively continue analysis for all immediately dominated blocks.
   int length = block->dominated_blocks()->length();
   for (int i = 0; i < length; ++i) {
@@ skipping 279 matching lines @@
       PropagateMinusZeroChecks(div->right(), visited);
     }
 
     current = current->EnsureAndPropagateNotMinusZero(visited);
   }
 }
 
 
 void HGraph::InsertRepresentationChangeForUse(HValue* value,
                                               HValue* use,
-                                              Representation to,
-                                              bool is_truncating) {
+                                              Representation to) {
   // Insert the representation change right before its use. For phi-uses we
   // insert at the end of the corresponding predecessor.
   HInstruction* next = NULL;
   if (use->IsPhi()) {
     int index = 0;
     while (use->OperandAt(index) != value) ++index;
     next = use->block()->predecessors()->at(index)->end();
   } else {
     next = HInstruction::cast(use);
   }
 
   // For constants we try to make the representation change at compile
   // time. When a representation change is not possible without loss of
   // information we treat constants like normal instructions and insert the
   // change instructions for them.
   HInstruction* new_value = NULL;
+  bool is_truncating = use->CheckFlag(HValue::kTruncatingToInt32);
   if (value->IsConstant()) {
     HConstant* constant = HConstant::cast(value);
     // Try to create a new copy of the constant with the new representation.
     new_value = is_truncating
         ? constant->CopyToTruncatedInt32()
         : constant->CopyToRepresentation(to);
   }
 
   if (new_value == NULL) {
-    new_value = new HChange(value, value->representation(), to);
+    new_value = new HChange(value, value->representation(), to, is_truncating);
   }
 
   new_value->InsertBefore(next);
   value->ReplaceFirstAtUse(use, new_value, to);
 }
 
 
 int CompareConversionUses(HValue* a,
                           HValue* b,
                           Representation a_rep,
                           Representation b_rep) {
   if (a_rep.kind() > b_rep.kind()) {
     // Make sure specializations are separated in the result array.
     return 1;
   }
   // Put truncating conversions before non-truncating conversions.
   bool a_truncate = a->CheckFlag(HValue::kTruncatingToInt32);
   bool b_truncate = b->CheckFlag(HValue::kTruncatingToInt32);
   if (a_truncate != b_truncate) {
     return a_truncate ? -1 : 1;
   }
   // Sort by increasing block ID.
   return a->block()->block_id() - b->block()->block_id();
 }
 
 
-void HGraph::InsertRepresentationChanges(HValue* current) {
+void HGraph::InsertRepresentationChangesForValue(
+    HValue* current,
+    ZoneList<HValue*>* to_convert,
+    ZoneList<Representation>* to_convert_reps) {
   Representation r = current->representation();
   if (r.IsNone()) return;
   if (current->uses()->length() == 0) return;
 
   // Collect the representation changes in a sorted list.  This allows
   // us to avoid duplicate changes without searching the list.
-  ZoneList<HValue*> to_convert(2);
-  ZoneList<Representation> to_convert_reps(2);
+  ASSERT(to_convert->is_empty());
+  ASSERT(to_convert_reps->is_empty());
   for (int i = 0; i < current->uses()->length(); ++i) {
     HValue* use = current->uses()->at(i);
     // The occurrences index means the index within the operand array of "use"
     // at which "current" is used. While iterating through the use array we
     // also have to iterate over the different occurrence indices.
     int occurrence_index = 0;
     if (use->UsesMultipleTimes(current)) {
       occurrence_index = current->uses()->CountOccurrences(use, 0, i - 1);
       if (FLAG_trace_representation) {
         PrintF("Instruction %d is used multiple times at %d; occurrence=%d\n",
                current->id(),
                use->id(),
                occurrence_index);
       }
     }
     int operand_index = use->LookupOperandIndex(occurrence_index, current);
     Representation req = use->RequiredInputRepresentation(operand_index);
     if (req.IsNone() || req.Equals(r)) continue;
     int index = 0;
-    while (to_convert.length() > index &&
-           CompareConversionUses(to_convert[index],
+    while (index < to_convert->length() &&
+           CompareConversionUses(to_convert->at(index),
                                  use,
-                                 to_convert_reps[index],
+                                 to_convert_reps->at(index),
                                  req) < 0) {
       ++index;
     }
     if (FLAG_trace_representation) {
       PrintF("Inserting a representation change to %s of %d for use at %d\n",
              req.Mnemonic(),
              current->id(),
              use->id());
     }
-    to_convert.InsertAt(index, use);
-    to_convert_reps.InsertAt(index, req);
+    to_convert->InsertAt(index, use);
+    to_convert_reps->InsertAt(index, req);
   }
 
-  for (int i = 0; i < to_convert.length(); ++i) {
-    HValue* use = to_convert[i];
-    Representation r_to = to_convert_reps[i];
-    bool is_truncating = use->CheckFlag(HValue::kTruncatingToInt32);
-    InsertRepresentationChangeForUse(current, use, r_to, is_truncating);
+  for (int i = 0; i < to_convert->length(); ++i) {
+    HValue* use = to_convert->at(i);
+    Representation r_to = to_convert_reps->at(i);
+    InsertRepresentationChangeForUse(current, use, r_to);
   }
 
   if (current->uses()->is_empty()) {
     ASSERT(current->IsConstant());
     current->Delete();
   }
+  to_convert->Rewind(0);
+  to_convert_reps->Rewind(0);
 }
 
 
 void HGraph::InsertRepresentationChanges() {
   HPhase phase("Insert representation changes", this);
 
 
   // Compute truncation flag for phis: Initially assume that all
   // int32-phis allow truncation and iteratively remove the ones that
   // are used in an operation that does not allow a truncating
@@ skipping 15 matching lines @@
         HValue* use = phi->uses()->at(j);
         if (!use->CheckFlag(HValue::kTruncatingToInt32)) {
           phi->ClearFlag(HValue::kTruncatingToInt32);
           change = true;
           break;
         }
       }
     }
   }
 
+  ZoneList<HValue*> value_list(4);
+  ZoneList<Representation> rep_list(4);
   for (int i = 0; i < blocks_.length(); ++i) {
     // Process phi instructions first.
     for (int j = 0; j < blocks_[i]->phis()->length(); j++) {
       HPhi* phi = blocks_[i]->phis()->at(j);
-      InsertRepresentationChanges(phi);
+      InsertRepresentationChangesForValue(phi, &value_list, &rep_list);
     }
 
     // Process normal instructions.
     HInstruction* current = blocks_[i]->first();
     while (current != NULL) {
-      InsertRepresentationChanges(current);
+      InsertRepresentationChangesForValue(current, &value_list, &rep_list);
       current = current->next();
     }
   }
 }
 
 
 void HGraph::ComputeMinusZeroChecks() {
   BitVector visited(GetMaximumValueID());
   for (int i = 0; i < blocks_.length(); ++i) {
     for (HInstruction* current = blocks_[i]->first();
@@ skipping 10 matching lines @@
           ASSERT(visited.IsEmpty());
           PropagateMinusZeroChecks(change->value(), &visited);
           visited.Clear();
         }
       }
     }
   }
 }
 
 
+// Implementation of utility class to encapsulate the translation state for
+// a (possibly inlined) function.
+FunctionState::FunctionState(HGraphBuilder* owner,
+                             CompilationInfo* info,
+                             TypeFeedbackOracle* oracle)
+    : owner_(owner),
+      compilation_info_(info),
+      oracle_(oracle),
+      call_context_(NULL),
+      function_return_(NULL),
+      test_context_(NULL),
+      outer_(owner->function_state()) {
+  if (outer_ != NULL) {
+    // State for an inline function.
+    if (owner->ast_context()->IsTest()) {
+      HBasicBlock* if_true = owner->graph()->CreateBasicBlock();
+      HBasicBlock* if_false = owner->graph()->CreateBasicBlock();
+      if_true->MarkAsInlineReturnTarget();
+      if_false->MarkAsInlineReturnTarget();
+      // The AstContext constructor pushed on the context stack.  This newed
+      // instance is the reason that AstContext can't be BASE_EMBEDDED.
+      test_context_ = new TestContext(owner, if_true, if_false);
+    } else {
+      function_return_ = owner->graph()->CreateBasicBlock();
+      function_return()->MarkAsInlineReturnTarget();
+    }
+    // Set this after possibly allocating a new TestContext above.
+    call_context_ = owner->ast_context();
+  }
+
+  // Push on the state stack.
+  owner->set_function_state(this);
+}
+
+
+FunctionState::~FunctionState() {
+  delete test_context_;
+  owner_->set_function_state(outer_);
+}
+
+
 // Implementation of utility classes to represent an expression's context in
 // the AST.
 AstContext::AstContext(HGraphBuilder* owner, Expression::Context kind)
     : owner_(owner), kind_(kind), outer_(owner->ast_context()) {
   owner->set_ast_context(this);  // Push.
 #ifdef DEBUG
   original_length_ = owner->environment()->length();
 #endif
 }
 
 
 AstContext::~AstContext() {
   owner_->set_ast_context(outer_);  // Pop.
 }
 
 
 EffectContext::~EffectContext() {
   ASSERT(owner()->HasStackOverflow() ||
-         !owner()->subgraph()->HasExit() ||
+         owner()->current_block() == NULL ||
          owner()->environment()->length() == original_length_);
 }
 
 
 ValueContext::~ValueContext() {
   ASSERT(owner()->HasStackOverflow() ||
-         !owner()->subgraph()->HasExit() ||
+         owner()->current_block() == NULL ||
          owner()->environment()->length() == original_length_ + 1);
 }
 
 
 void EffectContext::ReturnValue(HValue* value) {
   // The value is simply ignored.
 }
 
 
 void ValueContext::ReturnValue(HValue* value) {
@@ skipping 37 matching lines @@
 
 void TestContext::BuildBranch(HValue* value) {
   // We expect the graph to be in edge-split form: there is no edge that
   // connects a branch node to a join node.  We conservatively ensure that
   // property by always adding an empty block on the outgoing edges of this
   // branch.
   HGraphBuilder* builder = owner();
   HBasicBlock* empty_true = builder->graph()->CreateBasicBlock();
   HBasicBlock* empty_false = builder->graph()->CreateBasicBlock();
   HTest* test = new HTest(value, empty_true, empty_false);
-  builder->CurrentBlock()->Finish(test);
+  builder->current_block()->Finish(test);
 
-  HValue* const no_return_value = NULL;
-  HBasicBlock* true_target = if_true();
-  if (true_target->IsInlineReturnTarget()) {
-    empty_true->AddLeaveInlined(no_return_value, true_target);
-  } else {
-    empty_true->Goto(true_target);
-  }
-
-  HBasicBlock* false_target = if_false();
-  if (false_target->IsInlineReturnTarget()) {
-    empty_false->AddLeaveInlined(no_return_value, false_target);
-  } else {
-    empty_false->Goto(false_target);
-  }
-  builder->subgraph()->set_exit_block(NULL);
+  empty_true->Goto(if_true(), false);
+  empty_false->Goto(if_false(), false);
+  builder->set_current_block(NULL);
 }
 
 
 // HGraphBuilder infrastructure for bailing out and checking bailouts.
 #define BAILOUT(reason)                         \
   do {                                          \
     Bailout(reason);                            \
     return;                                     \
   } while (false)
 
@@ skipping 18 matching lines @@
   } while (false)
 
 
 #define VISIT_FOR_CONTROL(expr, true_block, false_block)        \
   do {                                                          \
     VisitForControl(expr, true_block, false_block);             \
     if (HasStackOverflow()) return;                             \
   } while (false)
 
 
-// 'thing' could be an expression, statement, or list of statements.
-#define ADD_TO_SUBGRAPH(graph, thing)       \
-  do {                                      \
-    AddToSubgraph(graph, thing);            \
-    if (HasStackOverflow()) return;         \
-  } while (false)
-
-
-class HGraphBuilder::SubgraphScope BASE_EMBEDDED {
- public:
-  SubgraphScope(HGraphBuilder* builder, HSubgraph* new_subgraph)
-      : builder_(builder) {
-    old_subgraph_ = builder_->current_subgraph_;
-    subgraph_ = new_subgraph;
-    builder_->current_subgraph_ = subgraph_;
-  }
-
-  ~SubgraphScope() {
-    old_subgraph_->AddBreakContinueInfo(subgraph_);
-    builder_->current_subgraph_ = old_subgraph_;
-  }
-
-  HSubgraph* subgraph() const { return subgraph_; }
-
- private:
-  HGraphBuilder* builder_;
-  HSubgraph* old_subgraph_;
-  HSubgraph* subgraph_;
-};
-
-
 void HGraphBuilder::Bailout(const char* reason) {
   if (FLAG_trace_bailout) {
-    SmartPointer<char> debug_name = graph()->debug_name()->ToCString();
-    PrintF("Bailout in HGraphBuilder: @\"%s\": %s\n", *debug_name, reason);
+    SmartPointer<char> name(info()->shared_info()->DebugName()->ToCString());
+    PrintF("Bailout in HGraphBuilder: @\"%s\": %s\n", *name, reason);
   }
   SetStackOverflow();
 }
 
 
 void HGraphBuilder::VisitForEffect(Expression* expr) {
   EffectContext for_effect(this);
   Visit(expr);
 }
 
 
 void HGraphBuilder::VisitForValue(Expression* expr) {
   ValueContext for_value(this);
   Visit(expr);
 }
 
 
 void HGraphBuilder::VisitForControl(Expression* expr,
                                     HBasicBlock* true_block,
                                     HBasicBlock* false_block) {
   TestContext for_test(this, true_block, false_block);
   Visit(expr);
 }
 
 
 void HGraphBuilder::VisitArgument(Expression* expr) {
-  VisitForValue(expr);
+  VISIT_FOR_VALUE(expr);
+  Push(AddInstruction(new HPushArgument(Pop())));
 }
 
 
 void HGraphBuilder::VisitArgumentList(ZoneList<Expression*>* arguments) {
   for (int i = 0; i < arguments->length(); i++) {
     VisitArgument(arguments->at(i));
-    if (HasStackOverflow() || !current_subgraph_->HasExit()) return;
+    if (HasStackOverflow() || current_block() == NULL) return;
   }
 }
 
 
-HGraph* HGraphBuilder::CreateGraph(CompilationInfo* info) {
-  ASSERT(current_subgraph_ == NULL);
-  graph_ = new HGraph(info);
+void HGraphBuilder::VisitExpressions(ZoneList<Expression*>* exprs) {
+  for (int i = 0; i < exprs->length(); ++i) {
+    VISIT_FOR_VALUE(exprs->at(i));
+  }
+}
+
+
+HGraph* HGraphBuilder::CreateGraph() {
+  graph_ = new HGraph(info());
+  if (FLAG_hydrogen_stats) HStatistics::Instance()->Initialize(info());
 
   {
     HPhase phase("Block building");
-    graph_->Initialize(CreateBasicBlock(graph_->start_environment()));
-    current_subgraph_ = graph_;
+    current_block_ = graph()->entry_block();
 
-    Scope* scope = info->scope();
+    Scope* scope = info()->scope();
+    if (scope->HasIllegalRedeclaration()) {
+      Bailout("function with illegal redeclaration");
+      return NULL;
+    }
     SetupScope(scope);
     VisitDeclarations(scope->declarations());
-
     AddInstruction(new HStackCheck());
 
-    ZoneList<Statement*>* stmts = info->function()->body();
-    HSubgraph* body = CreateGotoSubgraph(environment());
-    AddToSubgraph(body, stmts);
+    // Add an edge to the body entry.  This is warty: the graph's start
+    // environment will be used by the Lithium translation as the initial
+    // environment on graph entry, but it has now been mutated by the
+    // Hydrogen translation of the instructions in the start block.  This
+    // environment uses values which have not been defined yet.  These
+    // Hydrogen instructions will then be replayed by the Lithium
+    // translation, so they cannot have an environment effect.  The edge to
+    // the body's entry block (along with some special logic for the start
+    // block in HInstruction::InsertAfter) seals the start block from
+    // getting unwanted instructions inserted.
+    //
+    // TODO(kmillikin): Fix this.  Stop mutating the initial environment.
+    // Make the Hydrogen instructions in the initial block into Hydrogen
+    // values (but not instructions), present in the initial environment and
+    // not replayed by the Lithium translation.
+    HEnvironment* initial_env = environment()->CopyWithoutHistory();
+    HBasicBlock* body_entry = CreateBasicBlock(initial_env);
+    current_block()->Goto(body_entry);
+    body_entry->SetJoinId(info()->function()->id());
+    set_current_block(body_entry);
+    VisitStatements(info()->function()->body());
     if (HasStackOverflow()) return NULL;
-    current_subgraph_->Append(body, NULL);
-    body->entry_block()->SetJoinId(info->function()->id());
 
-    if (graph_->HasExit()) {
-      graph_->FinishExit(new HReturn(graph_->GetConstantUndefined()));
+    if (current_block() != NULL) {
+      HReturn* instr = new HReturn(graph()->GetConstantUndefined());
+      current_block()->FinishExit(instr);
+      set_current_block(NULL);
     }
   }
 
-  graph_->OrderBlocks();
-  graph_->AssignDominators();
-  graph_->EliminateRedundantPhis();
-  if (!graph_->CollectPhis()) {
+  graph()->OrderBlocks();
+  graph()->AssignDominators();
+  graph()->EliminateRedundantPhis();
+  if (FLAG_eliminate_dead_phis) graph()->EliminateUnreachablePhis();
+  if (!graph()->CollectPhis()) {
     Bailout("Phi-use of arguments object");
     return NULL;
   }
 
-  HInferRepresentation rep(graph_);
+  HInferRepresentation rep(graph());
   rep.Analyze();
 
   if (FLAG_use_range) {
-    HRangeAnalysis rangeAnalysis(graph_);
+    HRangeAnalysis rangeAnalysis(graph());
     rangeAnalysis.Analyze();
   }
 
-  graph_->InitializeInferredTypes();
-  graph_->Canonicalize();
-  graph_->InsertRepresentationChanges();
-  graph_->ComputeMinusZeroChecks();
+  graph()->InitializeInferredTypes();
+  graph()->Canonicalize();
+  graph()->InsertRepresentationChanges();
+  graph()->ComputeMinusZeroChecks();
 
   // Eliminate redundant stack checks on backwards branches.
-  HStackCheckEliminator sce(graph_);
+  HStackCheckEliminator sce(graph());
   sce.Process();
 
   // Perform common subexpression elimination and loop-invariant code motion.
   if (FLAG_use_gvn) {
-    HPhase phase("Global value numbering", graph_);
-    HGlobalValueNumberer gvn(graph_);
+    HPhase phase("Global value numbering", graph());
+    HGlobalValueNumberer gvn(graph(), info());
     gvn.Analyze();
   }
 
-  return graph_;
-}
-
-
-void HGraphBuilder::AddToSubgraph(HSubgraph* graph, Statement* stmt) {
-  SubgraphScope scope(this, graph);
-  Visit(stmt);
-}
-
-
-void HGraphBuilder::AddToSubgraph(HSubgraph* graph, Expression* expr) {
-  SubgraphScope scope(this, graph);
-  VisitForValue(expr);
-}
-
-
-void HGraphBuilder::AddToSubgraph(HSubgraph* graph,
-                                  ZoneList<Statement*>* stmts) {
-  SubgraphScope scope(this, graph);
-  VisitStatements(stmts);
+  return graph();
 }
 
 
 HInstruction* HGraphBuilder::AddInstruction(HInstruction* instr) {
-  ASSERT(current_subgraph_->HasExit());
-  current_subgraph_->exit_block()->AddInstruction(instr);
+  ASSERT(current_block() != NULL);
+  current_block()->AddInstruction(instr);
   return instr;
 }
 
 
 void HGraphBuilder::AddSimulate(int id) {
-  ASSERT(current_subgraph_->HasExit());
-  current_subgraph_->exit_block()->AddSimulate(id);
+  ASSERT(current_block() != NULL);
+  current_block()->AddSimulate(id);
 }
 
 
 void HGraphBuilder::AddPhi(HPhi* instr) {
-  ASSERT(current_subgraph_->HasExit());
-  current_subgraph_->exit_block()->AddPhi(instr);
+  ASSERT(current_block() != NULL);
+  current_block()->AddPhi(instr);
 }
 
 
 void HGraphBuilder::PushAndAdd(HInstruction* instr) {
   Push(instr);
   AddInstruction(instr);
 }
 
 
-void HGraphBuilder::PreProcessCall(HCall* call) {
+template <int V>
+HInstruction* HGraphBuilder::PreProcessCall(HCall<V>* call) {
   int count = call->argument_count();
   ZoneList<HValue*> arguments(count);
   for (int i = 0; i < count; ++i) {
     arguments.Add(Pop());
   }
 
   while (!arguments.is_empty()) {
     AddInstruction(new HPushArgument(arguments.RemoveLast()));
   }
+  return call;
 }
 
 
 void HGraphBuilder::SetupScope(Scope* scope) {
   // We don't yet handle the function name for named function expressions.
   if (scope->function() != NULL) BAILOUT("named function expression");
 
-  // We can't handle heap-allocated locals.
-  if (scope->num_heap_slots() > 0) BAILOUT("heap allocated locals");
-
   HConstant* undefined_constant =
       new HConstant(Factory::undefined_value(), Representation::Tagged());
   AddInstruction(undefined_constant);
   graph_->set_undefined_constant(undefined_constant);
 
   // Set the initial values of parameters including "this".  "This" has
   // parameter index 0.
   int count = scope->num_parameters() + 1;
   for (int i = 0; i < count; ++i) {
     HInstruction* parameter = AddInstruction(new HParameter(i));
     environment()->Bind(i, parameter);
   }
 
   // Set the initial values of stack-allocated locals.
   for (int i = count; i < environment()->length(); ++i) {
     environment()->Bind(i, undefined_constant);
   }
 
   // Handle the arguments and arguments shadow variables specially (they do
   // not have declarations).
   if (scope->arguments() != NULL) {
+    if (!scope->arguments()->IsStackAllocated() ||
+        (scope->arguments_shadow() != NULL &&
+        !scope->arguments_shadow()->IsStackAllocated())) {
+      BAILOUT("context-allocated arguments");
+    }
     HArgumentsObject* object = new HArgumentsObject;
     AddInstruction(object);
     graph()->SetArgumentsObject(object);
     environment()->Bind(scope->arguments(), object);
-    environment()->Bind(scope->arguments_shadow(), object);
+    if (scope->arguments_shadow() != NULL) {
+      environment()->Bind(scope->arguments_shadow(), object);
+    }
   }
 }
 
 
 void HGraphBuilder::VisitStatements(ZoneList<Statement*>* statements) {
   for (int i = 0; i < statements->length(); i++) {
     Visit(statements->at(i));
-    if (HasStackOverflow() || !current_subgraph_->HasExit()) break;
+    if (HasStackOverflow() || current_block() == NULL) break;
   }
 }
 
 
 HBasicBlock* HGraphBuilder::CreateBasicBlock(HEnvironment* env) {
   HBasicBlock* b = graph()->CreateBasicBlock();
   b->SetInitialEnvironment(env);
   return b;
 }
 
 
-HSubgraph* HGraphBuilder::CreateInlinedSubgraph(HEnvironment* outer,
-                                                Handle<JSFunction> target,
-                                                FunctionLiteral* function) {
-  HConstant* undefined = graph()->GetConstantUndefined();
-  HEnvironment* inner =
-      outer->CopyForInlining(target, function, true, undefined);
-  HSubgraph* subgraph = new HSubgraph(graph());
-  subgraph->Initialize(CreateBasicBlock(inner));
-  return subgraph;
-}
-
-
-HSubgraph* HGraphBuilder::CreateGotoSubgraph(HEnvironment* env) {
-  HSubgraph* subgraph = new HSubgraph(graph());
-  HEnvironment* new_env = env->CopyWithoutHistory();
-  subgraph->Initialize(CreateBasicBlock(new_env));
-  return subgraph;
-}
-
-
-HSubgraph* HGraphBuilder::CreateEmptySubgraph() {
-  HSubgraph* subgraph = new HSubgraph(graph());
-  subgraph->Initialize(graph()->CreateBasicBlock());
-  return subgraph;
-}
-
-
-HSubgraph* HGraphBuilder::CreateBranchSubgraph(HEnvironment* env) {
-  HSubgraph* subgraph = new HSubgraph(graph());
-  HEnvironment* new_env = env->Copy();
-  subgraph->Initialize(CreateBasicBlock(new_env));
-  return subgraph;
-}
-
-
-HSubgraph* HGraphBuilder::CreateLoopHeaderSubgraph(HEnvironment* env) {
-  HSubgraph* subgraph = new HSubgraph(graph());
-  HBasicBlock* block = graph()->CreateBasicBlock();
-  HEnvironment* new_env = env->CopyAsLoopHeader(block);
-  block->SetInitialEnvironment(new_env);
-  subgraph->Initialize(block);
-  subgraph->entry_block()->AttachLoopInformation();
-  return subgraph;
+HBasicBlock* HGraphBuilder::CreateLoopHeaderBlock() {
+  HBasicBlock* header = graph()->CreateBasicBlock();
+  HEnvironment* entry_env = environment()->CopyAsLoopHeader(header);
+  header->SetInitialEnvironment(entry_env);
+  header->AttachLoopInformation();
+  return header;
 }
 
 
 void HGraphBuilder::VisitBlock(Block* stmt) {
-  if (stmt->labels() != NULL) {
-    HSubgraph* block_graph = CreateGotoSubgraph(environment());
-    ADD_TO_SUBGRAPH(block_graph, stmt->statements());
-    current_subgraph_->Append(block_graph, stmt);
-  } else {
+  BreakAndContinueInfo break_info(stmt);
+  { BreakAndContinueScope push(&break_info, this);
     VisitStatements(stmt->statements());
+    CHECK_BAILOUT;
+  }
+  HBasicBlock* break_block = break_info.break_block();
+  if (break_block != NULL) {
+    if (current_block() != NULL) current_block()->Goto(break_block);
+    break_block->SetJoinId(stmt->ExitId());
+    set_current_block(break_block);
   }
 }
 
 
 void HGraphBuilder::VisitExpressionStatement(ExpressionStatement* stmt) {
   VisitForEffect(stmt->expression());
 }
 
 
 void HGraphBuilder::VisitEmptyStatement(EmptyStatement* stmt) {
 }
 
 
 void HGraphBuilder::VisitIfStatement(IfStatement* stmt) {
   if (stmt->condition()->ToBooleanIsTrue()) {
     AddSimulate(stmt->ThenId());
     Visit(stmt->then_statement());
   } else if (stmt->condition()->ToBooleanIsFalse()) {
     AddSimulate(stmt->ElseId());
     Visit(stmt->else_statement());
   } else {
-    HSubgraph* then_graph = CreateEmptySubgraph();
-    HSubgraph* else_graph = CreateEmptySubgraph();
-    VISIT_FOR_CONTROL(stmt->condition(),
-                      then_graph->entry_block(),
-                      else_graph->entry_block());
+    HBasicBlock* cond_true = graph()->CreateBasicBlock();
+    HBasicBlock* cond_false = graph()->CreateBasicBlock();
+    VISIT_FOR_CONTROL(stmt->condition(), cond_true, cond_false);
+    cond_true->SetJoinId(stmt->ThenId());
+    cond_false->SetJoinId(stmt->ElseId());
 
-    then_graph->entry_block()->SetJoinId(stmt->ThenId());
-    ADD_TO_SUBGRAPH(then_graph, stmt->then_statement());
+    set_current_block(cond_true);
+    Visit(stmt->then_statement());
+    CHECK_BAILOUT;
+    HBasicBlock* other = current_block();
 
-    else_graph->entry_block()->SetJoinId(stmt->ElseId());
-    ADD_TO_SUBGRAPH(else_graph, stmt->else_statement());
+    set_current_block(cond_false);
+    Visit(stmt->else_statement());
+    CHECK_BAILOUT;
 
-    current_subgraph_->AppendJoin(then_graph, else_graph, stmt);
+    HBasicBlock* join = CreateJoin(other, current_block(), stmt->id());
+    set_current_block(join);
   }
 }
 
 
+HBasicBlock* HGraphBuilder::BreakAndContinueScope::Get(
+    BreakableStatement* stmt,
+    BreakType type) {
+  BreakAndContinueScope* current = this;
+  while (current != NULL && current->info()->target() != stmt) {
+    current = current->next();
+  }
+  ASSERT(current != NULL);  // Always found (unless stack is malformed).
+  HBasicBlock* block = NULL;
+  switch (type) {
+    case BREAK:
+      block = current->info()->break_block();
+      if (block == NULL) {
+        block = current->owner()->graph()->CreateBasicBlock();
+        current->info()->set_break_block(block);
+      }
+      break;
+
+    case CONTINUE:
+      block = current->info()->continue_block();
+      if (block == NULL) {
+        block = current->owner()->graph()->CreateBasicBlock();
+        current->info()->set_continue_block(block);
+      }
+      break;
+  }
+
+  return block;
+}
+
+
 void HGraphBuilder::VisitContinueStatement(ContinueStatement* stmt) {
-  current_subgraph_->FinishBreakContinue(stmt->target(), true);
+  HBasicBlock* continue_block = break_scope()->Get(stmt->target(), CONTINUE);
+  current_block()->Goto(continue_block);
+  set_current_block(NULL);
 }
 
 
 void HGraphBuilder::VisitBreakStatement(BreakStatement* stmt) {
-  current_subgraph_->FinishBreakContinue(stmt->target(), false);
+  HBasicBlock* break_block = break_scope()->Get(stmt->target(), BREAK);
+  current_block()->Goto(break_block);
+  set_current_block(NULL);
 }
 
 
 void HGraphBuilder::VisitReturnStatement(ReturnStatement* stmt) {
   AstContext* context = call_context();
   if (context == NULL) {
     // Not an inlined return, so an actual one.
     VISIT_FOR_VALUE(stmt->expression());
     HValue* result = environment()->Pop();
-    subgraph()->FinishExit(new HReturn(result));
+    current_block()->FinishExit(new HReturn(result));
+    set_current_block(NULL);
   } else {
     // Return from an inlined function, visit the subexpression in the
     // expression context of the call.
     if (context->IsTest()) {
       TestContext* test = TestContext::cast(context);
       VisitForControl(stmt->expression(),
                       test->if_true(),
                       test->if_false());
+    } else if (context->IsEffect()) {
+      VISIT_FOR_EFFECT(stmt->expression());
+      current_block()->Goto(function_return(), false);
     } else {
-      HValue* return_value = NULL;
-      if (context->IsEffect()) {
-        VISIT_FOR_EFFECT(stmt->expression());
-        return_value = graph()->GetConstantUndefined();
-      } else {
-        ASSERT(context->IsValue());
-        VISIT_FOR_VALUE(stmt->expression());
-        return_value = environment()->Pop();
-      }
-      subgraph()->exit_block()->AddLeaveInlined(return_value,
-                                                function_return_);
-      subgraph()->set_exit_block(NULL);
+      ASSERT(context->IsValue());
+      VISIT_FOR_VALUE(stmt->expression());
+      HValue* return_value = environment()->Pop();
+      current_block()->AddLeaveInlined(return_value, function_return());
     }
+    set_current_block(NULL);
   }
 }
 
 
 void HGraphBuilder::VisitWithEnterStatement(WithEnterStatement* stmt) {
   BAILOUT("WithEnterStatement");
 }
 
 
 void HGraphBuilder::VisitWithExitStatement(WithExitStatement* stmt) {
   BAILOUT("WithExitStatement");
 }
 
 
-HCompare* HGraphBuilder::BuildSwitchCompare(HSubgraph* subgraph,
-                                            HValue* switch_value,
-                                            CaseClause* clause) {
-  AddToSubgraph(subgraph, clause->label());
-  if (HasStackOverflow()) return NULL;
-  HValue* clause_value = subgraph->environment()->Pop();
-  HCompare* compare = new HCompare(switch_value,
-                                   clause_value,
-                                   Token::EQ_STRICT);
-  compare->SetInputRepresentation(Representation::Integer32());
-  subgraph->exit_block()->AddInstruction(compare);
-  return compare;
-}
-
-
 void HGraphBuilder::VisitSwitchStatement(SwitchStatement* stmt) {
+  // We only optimize switch statements with smi-literal smi comparisons,
+  // with a bounded number of clauses.
+  const int kCaseClauseLimit = 128;
+  ZoneList<CaseClause*>* clauses = stmt->cases();
+  int clause_count = clauses->length();
+  if (clause_count > kCaseClauseLimit) {
+    BAILOUT("SwitchStatement: too many clauses");
+  }
+
   VISIT_FOR_VALUE(stmt->tag());
-  // TODO(3168478): simulate added for tag should be enough.
-  AddSimulate(stmt->EntryId());
-  HValue* switch_value = Pop();
-
-  ZoneList<CaseClause*>* clauses = stmt->cases();
-  int num_clauses = clauses->length();
-  if (num_clauses == 0) return;
-  if (num_clauses > 128) BAILOUT("SwitchStatement: too many clauses");
-
-  int num_smi_clauses = num_clauses;
-  for (int i = 0; i < num_clauses; i++) {
+  HValue* tag_value = Pop();
+  HBasicBlock* first_test_block = current_block();
+
+  // 1. Build all the tests, with dangling true branches.  Unconditionally
+  // deoptimize if we encounter a non-smi comparison.
+  for (int i = 0; i < clause_count; ++i) {
     CaseClause* clause = clauses->at(i);
     if (clause->is_default()) continue;
-    clause->RecordTypeFeedback(oracle());
-    if (!clause->IsSmiCompare()) {
-      if (i == 0) BAILOUT("SwitchStatement: no smi compares");
-      // We will deoptimize if the first non-smi compare is reached.
-      num_smi_clauses = i;
-      break;
-    }
     if (!clause->label()->IsSmiLiteral()) {
       BAILOUT("SwitchStatement: non-literal switch label");
     }
-  }
-
-  // The single exit block of the whole switch statement.
-  HBasicBlock* single_exit_block = graph_->CreateBasicBlock();
-
-  // Build a series of empty subgraphs for the comparisons.
-  // The default clause does not have a comparison subgraph.
-  ZoneList<HSubgraph*> compare_graphs(num_smi_clauses);
-  for (int i = 0; i < num_smi_clauses; i++) {
-    if (clauses->at(i)->is_default()) {
-      compare_graphs.Add(NULL);
-    } else {
-      compare_graphs.Add(CreateEmptySubgraph());
+
+    // Unconditionally deoptimize on the first non-smi compare.
+    clause->RecordTypeFeedback(oracle());
+    if (!clause->IsSmiCompare()) {
+      if (current_block() == first_test_block) {
+        // If the first test is the one that deopts and if the tag value is
+        // a phi, we need to have some use of that phi to prevent phi
+        // elimination from removing it.  This HSimulate is such a use.
+        Push(tag_value);
+        AddSimulate(stmt->EntryId());
+        Drop(1);
+      }
+      current_block()->Finish(new HDeoptimize());
+      set_current_block(NULL);
+      break;
     }
-  }
-
-  HSubgraph* prev_graph = current_subgraph_;
-  HCompare* prev_compare_inst = NULL;
-  for (int i = 0; i < num_smi_clauses; i++) {
-    CaseClause* clause = clauses->at(i);
-    if (clause->is_default()) continue;
-
-    // Finish the previous graph by connecting it to the current.
-    HSubgraph* subgraph = compare_graphs.at(i);
-    if (prev_compare_inst == NULL) {
-      ASSERT(prev_graph == current_subgraph_);
-      prev_graph->exit_block()->Finish(new HGoto(subgraph->entry_block()));
-    } else {
-      HBasicBlock* empty = graph()->CreateBasicBlock();
-      prev_graph->exit_block()->Finish(new HTest(prev_compare_inst,
-                                                 empty,
-                                                 subgraph->entry_block()));
+
+    // Otherwise generate a compare and branch.
+    VISIT_FOR_VALUE(clause->label());
+    HValue* label_value = Pop();
+    HCompare* compare = new HCompare(tag_value, label_value, Token::EQ_STRICT);
+    compare->SetInputRepresentation(Representation::Integer32());
+    ASSERT(!compare->HasSideEffects());
+    AddInstruction(compare);
+    HBasicBlock* body_block = graph()->CreateBasicBlock();
+    HBasicBlock* next_test_block = graph()->CreateBasicBlock();
+    HTest* branch = new HTest(compare, body_block, next_test_block);
+    current_block()->Finish(branch);
+    set_current_block(next_test_block);
+  }
+
+  // Save the current block to use for the default or to join with the
+  // exit.  This block is NULL if we deoptimized.
+  HBasicBlock* last_block = current_block();
+
+  // 2. Loop over the clauses and the linked list of tests in lockstep,
+  // translating the clause bodies.
+  HBasicBlock* curr_test_block = first_test_block;
+  HBasicBlock* fall_through_block = NULL;
+  BreakAndContinueInfo break_info(stmt);
+  { BreakAndContinueScope push(&break_info, this);
+    for (int i = 0; i < clause_count; ++i) {
+      CaseClause* clause = clauses->at(i);
+
+      // Identify the block where normal (non-fall-through) control flow
+      // goes to.
+      HBasicBlock* normal_block = NULL;
+      if (clause->is_default() && last_block != NULL) {
+        normal_block = last_block;
+        last_block = NULL;  // Cleared to indicate we've handled it.
+      } else if (!curr_test_block->end()->IsDeoptimize()) {
+        normal_block = curr_test_block->end()->FirstSuccessor();
+        curr_test_block = curr_test_block->end()->SecondSuccessor();
+      }
+
+      // Identify a block to emit the body into.
+      if (normal_block == NULL) {
+        if (fall_through_block == NULL) {
+          // (a) Unreachable.
+          if (clause->is_default()) {
+            continue;  // Might still be reachable clause bodies.
+          } else {
+            break;
+          }
+        } else {
+          // (b) Reachable only as fall through.
+          set_current_block(fall_through_block);
+        }
+      } else if (fall_through_block == NULL) {
+        // (c) Reachable only normally.
+        set_current_block(normal_block);
+      } else {
+        // (d) Reachable both ways.
+        HBasicBlock* join = CreateJoin(fall_through_block,
+                                       normal_block,
+                                       clause->EntryId());
+        set_current_block(join);
+      }
+
+      VisitStatements(clause->statements());
+      CHECK_BAILOUT;
+      fall_through_block = current_block();
     }
-
-    // Build instructions for current subgraph.
-    ASSERT(clause->IsSmiCompare());
-    prev_compare_inst = BuildSwitchCompare(subgraph, switch_value, clause);
-    if (HasStackOverflow()) return;
-
-    prev_graph = subgraph;
-  }
-
-  // Finish last comparison if there was at least one comparison.
-  // last_false_block is the (empty) false-block of the last comparison. If
-  // there are no comparisons at all (a single default clause), it is just
-  // the last block of the current subgraph.
-  HBasicBlock* last_false_block = current_subgraph_->exit_block();
-  if (prev_graph != current_subgraph_) {
-    last_false_block = graph()->CreateBasicBlock();
-    HBasicBlock* empty = graph()->CreateBasicBlock();
-    prev_graph->exit_block()->Finish(new HTest(prev_compare_inst,
-                                               empty,
-                                               last_false_block));
-  }
-
-  // If we have a non-smi compare clause, we deoptimize after trying
-  // all the previous compares.
-  if (num_smi_clauses < num_clauses) {
-    last_false_block->Finish(new HDeoptimize);
-  }
-
-  // Build statement blocks, connect them to their comparison block and
-  // to the previous statement block, if there is a fall-through.
-  HSubgraph* previous_subgraph = NULL;
-  for (int i = 0; i < num_clauses; i++) {
-    CaseClause* clause = clauses->at(i);
-    // Subgraph for the statements of the clause is only created when
-    // it's reachable either from the corresponding compare or as a
-    // fall-through from previous statements.
-    HSubgraph* subgraph = NULL;
-
-    if (i < num_smi_clauses) {
-      if (clause->is_default()) {
-        if (!last_false_block->IsFinished()) {
-          // Default clause: Connect it to the last false block.
-          subgraph = CreateEmptySubgraph();
-          last_false_block->Finish(new HGoto(subgraph->entry_block()));
-        }
-      } else {
-        ASSERT(clause->IsSmiCompare());
-        // Connect with the corresponding comparison.
-        subgraph = CreateEmptySubgraph();
-        HBasicBlock* empty =
-            compare_graphs.at(i)->exit_block()->end()->FirstSuccessor();
-        empty->Finish(new HGoto(subgraph->entry_block()));
-      }
-    }
-
-    // Check for fall-through from previous statement block.
-    if (previous_subgraph != NULL && previous_subgraph->HasExit()) {
-      if (subgraph == NULL) subgraph = CreateEmptySubgraph();
-      previous_subgraph->exit_block()->
-          Finish(new HGoto(subgraph->entry_block()));
-    }
-
-    if (subgraph != NULL) {
-      ADD_TO_SUBGRAPH(subgraph, clause->statements());
-      HBasicBlock* break_block = subgraph->BundleBreak(stmt);
-      if (break_block != NULL) {
-        break_block->Finish(new HGoto(single_exit_block));
-      }
-    }
-
-    previous_subgraph = subgraph;
-  }
-
-  // If the last statement block has a fall-through, connect it to the
-  // single exit block.
-  if (previous_subgraph != NULL && previous_subgraph->HasExit()) {
-    previous_subgraph->exit_block()->Finish(new HGoto(single_exit_block));
-  }
-
-  // If there is no default clause finish the last comparison's false target.
-  if (!last_false_block->IsFinished()) {
-    last_false_block->Finish(new HGoto(single_exit_block));
-  }
-
-  if (single_exit_block->HasPredecessor()) {
-    current_subgraph_->set_exit_block(single_exit_block);
+  }
+
+  // Create an up-to-3-way join.  Use the break block if it exists since
+  // it's already a join block.
+  HBasicBlock* break_block = break_info.break_block();
+  if (break_block == NULL) {
+    set_current_block(CreateJoin(fall_through_block,
+                                 last_block,
+                                 stmt->ExitId()));
   } else {
-    current_subgraph_->set_exit_block(NULL);
-  }
-}
-
-bool HGraph::HasOsrEntryAt(IterationStatement* statement) {
+    if (fall_through_block != NULL) fall_through_block->Goto(break_block);
+    if (last_block != NULL) last_block->Goto(break_block);
+    break_block->SetJoinId(stmt->ExitId());
+    set_current_block(break_block);
+  }
+}
+
+
+bool HGraphBuilder::HasOsrEntryAt(IterationStatement* statement) {
   return statement->OsrEntryId() == info()->osr_ast_id();
 }
 
 
-void HSubgraph::PreProcessOsrEntry(IterationStatement* statement) {
-  if (!graph()->HasOsrEntryAt(statement)) return;
+void HGraphBuilder::PreProcessOsrEntry(IterationStatement* statement) {
+  if (!HasOsrEntryAt(statement)) return;
 
   HBasicBlock* non_osr_entry = graph()->CreateBasicBlock();
   HBasicBlock* osr_entry = graph()->CreateBasicBlock();
   HValue* true_value = graph()->GetConstantTrue();
   HTest* test = new HTest(true_value, non_osr_entry, osr_entry);
-  exit_block()->Finish(test);
+  current_block()->Finish(test);
 
   HBasicBlock* loop_predecessor = graph()->CreateBasicBlock();
   non_osr_entry->Goto(loop_predecessor);
 
+  set_current_block(osr_entry);
   int osr_entry_id = statement->OsrEntryId();
   // We want the correct environment at the OsrEntry instruction.  Build
   // it explicitly.  The expression stack should be empty.
-  int count = osr_entry->last_environment()->length();
-  ASSERT(count == (osr_entry->last_environment()->parameter_count() +
-                   osr_entry->last_environment()->local_count()));
+  int count = environment()->length();
+  ASSERT(count ==
+         (environment()->parameter_count() + environment()->local_count()));
   for (int i = 0; i < count; ++i) {
     HUnknownOSRValue* unknown = new HUnknownOSRValue;
-    osr_entry->AddInstruction(unknown);
-    osr_entry->last_environment()->Bind(i, unknown);
-  }
-
-  osr_entry->AddSimulate(osr_entry_id);
-  osr_entry->AddInstruction(new HOsrEntry(osr_entry_id));
-  osr_entry->Goto(loop_predecessor);
+    AddInstruction(unknown);
+    environment()->Bind(i, unknown);
+  }
+
+  AddSimulate(osr_entry_id);
+  AddInstruction(new HOsrEntry(osr_entry_id));
+  current_block()->Goto(loop_predecessor);
   loop_predecessor->SetJoinId(statement->EntryId());
-  set_exit_block(loop_predecessor);
+  set_current_block(loop_predecessor);
 }
 
 
 void HGraphBuilder::VisitDoWhileStatement(DoWhileStatement* stmt) {
-  ASSERT(subgraph()->HasExit());
-  subgraph()->PreProcessOsrEntry(stmt);
-
-  HSubgraph* body_graph = CreateLoopHeaderSubgraph(environment());
-  ADD_TO_SUBGRAPH(body_graph, stmt->body());
-  body_graph->ResolveContinue(stmt);
-
-  if (!body_graph->HasExit() || stmt->cond()->ToBooleanIsTrue()) {
-    current_subgraph_->AppendEndless(body_graph, stmt);
-  } else {
-    HSubgraph* go_back = CreateEmptySubgraph();
-    HSubgraph* exit = CreateEmptySubgraph();
-    {
-      SubgraphScope scope(this, body_graph);
-      VISIT_FOR_CONTROL(stmt->cond(),
-                        go_back->entry_block(),
-                        exit->entry_block());
-      go_back->entry_block()->SetJoinId(stmt->BackEdgeId());
-      exit->entry_block()->SetJoinId(stmt->ExitId());
-    }
-    current_subgraph_->AppendDoWhile(body_graph, stmt, go_back, exit);
-  }
-}
-
-
-bool HGraphBuilder::ShouldPeel(HSubgraph* cond, HSubgraph* body) {
-  return FLAG_use_peeling;
+  ASSERT(current_block() != NULL);
+  PreProcessOsrEntry(stmt);
+  HBasicBlock* loop_entry = CreateLoopHeaderBlock();
+  current_block()->Goto(loop_entry, false);
+  set_current_block(loop_entry);
+
+  BreakAndContinueInfo break_info(stmt);
+  { BreakAndContinueScope push(&break_info, this);
+    Visit(stmt->body());
+    CHECK_BAILOUT;
+  }
+  HBasicBlock* body_exit =
+      JoinContinue(stmt, current_block(), break_info.continue_block());
+  HBasicBlock* loop_successor = NULL;
+  if (body_exit != NULL && !stmt->cond()->ToBooleanIsTrue()) {
+    set_current_block(body_exit);
+    // The block for a true condition, the actual predecessor block of the
+    // back edge.
+    body_exit = graph()->CreateBasicBlock();
+    loop_successor = graph()->CreateBasicBlock();
+    VISIT_FOR_CONTROL(stmt->cond(), body_exit, loop_successor);
+    body_exit->SetJoinId(stmt->BackEdgeId());
+    loop_successor->SetJoinId(stmt->ExitId());
+  }
+  HBasicBlock* loop_exit = CreateLoop(stmt,
+                                      loop_entry,
+                                      body_exit,
+                                      loop_successor,
+                                      break_info.break_block());
+  set_current_block(loop_exit);
 }
 
 
 void HGraphBuilder::VisitWhileStatement(WhileStatement* stmt) {
-  ASSERT(subgraph()->HasExit());
-  subgraph()->PreProcessOsrEntry(stmt);
-
-  HSubgraph* cond_graph = NULL;
-  HSubgraph* body_graph = NULL;
-  HSubgraph* exit_graph = NULL;
-
-  // If the condition is constant true, do not generate a condition subgraph.
-  if (stmt->cond()->ToBooleanIsTrue()) {
-    body_graph = CreateLoopHeaderSubgraph(environment());
-    ADD_TO_SUBGRAPH(body_graph, stmt->body());
-  } else {
-    cond_graph = CreateLoopHeaderSubgraph(environment());
-    body_graph = CreateEmptySubgraph();
-    exit_graph = CreateEmptySubgraph();
-    {
-      SubgraphScope scope(this, cond_graph);
-      VISIT_FOR_CONTROL(stmt->cond(),
-                        body_graph->entry_block(),
-                        exit_graph->entry_block());
-      body_graph->entry_block()->SetJoinId(stmt->BodyId());
-      exit_graph->entry_block()->SetJoinId(stmt->ExitId());
-    }
-    ADD_TO_SUBGRAPH(body_graph, stmt->body());
-  }
-
-  body_graph->ResolveContinue(stmt);
-
-  if (cond_graph != NULL) {
-    AppendPeeledWhile(stmt, cond_graph, body_graph, exit_graph);
-  } else {
-    // TODO(fschneider): Implement peeling for endless loops as well.
-    current_subgraph_->AppendEndless(body_graph, stmt);
-  }
-}
-
-
-void HGraphBuilder::AppendPeeledWhile(IterationStatement* stmt,
-                                      HSubgraph* cond_graph,
-                                      HSubgraph* body_graph,
-                                      HSubgraph* exit_graph) {
-  HSubgraph* loop = NULL;
-  if (body_graph->HasExit() && stmt != peeled_statement_ &&
-      ShouldPeel(cond_graph, body_graph)) {
-    // Save the last peeled iteration statement to prevent infinite recursion.
-    IterationStatement* outer_peeled_statement = peeled_statement_;
-    peeled_statement_ = stmt;
-    loop = CreateGotoSubgraph(body_graph->environment());
-    ADD_TO_SUBGRAPH(loop, stmt);
-    peeled_statement_ = outer_peeled_statement;
-  }
-  current_subgraph_->AppendWhile(cond_graph, body_graph, stmt, loop,
-                                 exit_graph);
+  ASSERT(current_block() != NULL);
+  PreProcessOsrEntry(stmt);
+  HBasicBlock* loop_entry = CreateLoopHeaderBlock();
+  current_block()->Goto(loop_entry, false);
+  set_current_block(loop_entry);
+
+  // If the condition is constant true, do not generate a branch.
+  HBasicBlock* loop_successor = NULL;
+  if (!stmt->cond()->ToBooleanIsTrue()) {
+    HBasicBlock* body_entry = graph()->CreateBasicBlock();
+    loop_successor = graph()->CreateBasicBlock();
+    VISIT_FOR_CONTROL(stmt->cond(), body_entry, loop_successor);
+    body_entry->SetJoinId(stmt->BodyId());
+    loop_successor->SetJoinId(stmt->ExitId());
+    set_current_block(body_entry);
+  }
+
+  BreakAndContinueInfo break_info(stmt);
+  { BreakAndContinueScope push(&break_info, this);
+    Visit(stmt->body());
+    CHECK_BAILOUT;
+  }
+  HBasicBlock* body_exit =
+      JoinContinue(stmt, current_block(), break_info.continue_block());
+  HBasicBlock* loop_exit = CreateLoop(stmt,
+                                      loop_entry,
+                                      body_exit,
+                                      loop_successor,
+                                      break_info.break_block());
+  set_current_block(loop_exit);
 }
 
 
 void HGraphBuilder::VisitForStatement(ForStatement* stmt) {
-  // Only visit the init statement in the peeled part of the loop.
-  if (stmt->init() != NULL && peeled_statement_ != stmt) {
+  if (stmt->init() != NULL) {
     Visit(stmt->init());
     CHECK_BAILOUT;
   }
-  ASSERT(subgraph()->HasExit());
-  subgraph()->PreProcessOsrEntry(stmt);
-
-  HSubgraph* cond_graph = NULL;
-  HSubgraph* body_graph = NULL;
-  HSubgraph* exit_graph = NULL;
+  ASSERT(current_block() != NULL);
+  PreProcessOsrEntry(stmt);
+  HBasicBlock* loop_entry = CreateLoopHeaderBlock();
+  current_block()->Goto(loop_entry, false);
+  set_current_block(loop_entry);
+
+  HBasicBlock* loop_successor = NULL;
   if (stmt->cond() != NULL) {
-    cond_graph = CreateLoopHeaderSubgraph(environment());
-    body_graph = CreateEmptySubgraph();
-    exit_graph = CreateEmptySubgraph();
-    {
-      SubgraphScope scope(this, cond_graph);
-      VISIT_FOR_CONTROL(stmt->cond(),
-                        body_graph->entry_block(),
-                        exit_graph->entry_block());
-      body_graph->entry_block()->SetJoinId(stmt->BodyId());
-      exit_graph->entry_block()->SetJoinId(stmt->ExitId());
-    }
-  } else {
-    body_graph = CreateLoopHeaderSubgraph(environment());
-  }
-  ADD_TO_SUBGRAPH(body_graph, stmt->body());
-
-  HSubgraph* next_graph = NULL;
-  body_graph->ResolveContinue(stmt);
-
-  if (stmt->next() != NULL && body_graph->HasExit()) {
-    next_graph = CreateGotoSubgraph(body_graph->environment());
-    ADD_TO_SUBGRAPH(next_graph, stmt->next());
-    body_graph->Append(next_graph, NULL);
-    next_graph->entry_block()->SetJoinId(stmt->ContinueId());
-  }
-
-  if (cond_graph != NULL) {
-    AppendPeeledWhile(stmt, cond_graph, body_graph, exit_graph);
-  } else {
-    current_subgraph_->AppendEndless(body_graph, stmt);
-  }
-}
-
-
+    HBasicBlock* body_entry = graph()->CreateBasicBlock();
+    loop_successor = graph()->CreateBasicBlock();
+    VISIT_FOR_CONTROL(stmt->cond(), body_entry, loop_successor);
+    body_entry->SetJoinId(stmt->BodyId());
+    loop_successor->SetJoinId(stmt->ExitId());
+    set_current_block(body_entry);
+  }
+
+  BreakAndContinueInfo break_info(stmt);
+  { BreakAndContinueScope push(&break_info, this);
+    Visit(stmt->body());
+    CHECK_BAILOUT;
+  }
+  HBasicBlock* body_exit =
+      JoinContinue(stmt, current_block(), break_info.continue_block());
+
+  if (stmt->next() != NULL && body_exit != NULL) {
+    set_current_block(body_exit);
+    Visit(stmt->next());
+    CHECK_BAILOUT;
+    body_exit = current_block();
+  }
+
+  HBasicBlock* loop_exit = CreateLoop(stmt,
+                                      loop_entry,
+                                      body_exit,
+                                      loop_successor,
+                                      break_info.break_block());
+  set_current_block(loop_exit);
+}
+
+
 void HGraphBuilder::VisitForInStatement(ForInStatement* stmt) {
   BAILOUT("ForInStatement");
 }
 
 
 void HGraphBuilder::VisitTryCatchStatement(TryCatchStatement* stmt) {
   BAILOUT("TryCatchStatement");
 }
 
 
 void HGraphBuilder::VisitTryFinallyStatement(TryFinallyStatement* stmt) {
   BAILOUT("TryFinallyStatement");
 }
 
 
 void HGraphBuilder::VisitDebuggerStatement(DebuggerStatement* stmt) {
   BAILOUT("DebuggerStatement");
 }
 
 
 void HGraphBuilder::VisitFunctionLiteral(FunctionLiteral* expr) {
   Handle<SharedFunctionInfo> shared_info =
-      Compiler::BuildFunctionInfo(expr, graph_->info()->script());
+      Compiler::BuildFunctionInfo(expr, info()->script());
   CHECK_BAILOUT;
   HFunctionLiteral* instr =
       new HFunctionLiteral(shared_info, expr->pretenure());
   ast_context()->ReturnInstruction(instr, expr->id());
 }
 
 
 void HGraphBuilder::VisitSharedFunctionInfoLiteral(
     SharedFunctionInfoLiteral* expr) {
   BAILOUT("SharedFunctionInfoLiteral");
 }
 
 
 void HGraphBuilder::VisitConditional(Conditional* expr) {
-  HSubgraph* then_graph = CreateEmptySubgraph();
-  HSubgraph* else_graph = CreateEmptySubgraph();
-  VISIT_FOR_CONTROL(expr->condition(),
-                    then_graph->entry_block(),
-                    else_graph->entry_block());
+  HBasicBlock* cond_true = graph()->CreateBasicBlock();
+  HBasicBlock* cond_false = graph()->CreateBasicBlock();
+  VISIT_FOR_CONTROL(expr->condition(), cond_true, cond_false);
+  cond_true->SetJoinId(expr->ThenId());
+  cond_false->SetJoinId(expr->ElseId());
 
-  then_graph->entry_block()->SetJoinId(expr->ThenId());
-  ADD_TO_SUBGRAPH(then_graph, expr->then_expression());
+  // Visit the true and false subexpressions in the same AST context as the
+  // whole expression.
+  set_current_block(cond_true);
+  Visit(expr->then_expression());
+  CHECK_BAILOUT;
+  HBasicBlock* other = current_block();
 
-  else_graph->entry_block()->SetJoinId(expr->ElseId());
-  ADD_TO_SUBGRAPH(else_graph, expr->else_expression());
+  set_current_block(cond_false);
+  Visit(expr->else_expression());
+  CHECK_BAILOUT;
 
-  current_subgraph_->AppendJoin(then_graph, else_graph, expr);
-  ast_context()->ReturnValue(Pop());
+  if (!ast_context()->IsTest()) {
+    HBasicBlock* join = CreateJoin(other, current_block(), expr->id());
+    set_current_block(join);
+    if (!ast_context()->IsEffect()) ast_context()->ReturnValue(Pop());
+  }
 }
 
 
 void HGraphBuilder::LookupGlobalPropertyCell(Variable* var,
                                              LookupResult* lookup,
                                              bool is_store) {
   if (var->is_this()) {
     BAILOUT("global this reference");
   }
-  if (!graph()->info()->has_global_object()) {
+  if (!info()->has_global_object()) {
     BAILOUT("no global object to optimize VariableProxy");
   }
-  Handle<GlobalObject> global(graph()->info()->global_object());
+  Handle<GlobalObject> global(info()->global_object());
   global->Lookup(*var->name(), lookup);
   if (!lookup->IsProperty()) {
     BAILOUT("global variable cell not yet introduced");
   }
   if (lookup->type() != NORMAL) {
     BAILOUT("global variable has accessors");
   }
   if (is_store && lookup->IsReadOnly()) {
     BAILOUT("read-only global variable");
   }
   if (lookup->holder() != *global) {
     BAILOUT("global property on prototype of global object");
   }
 }
 
 
 HValue* HGraphBuilder::BuildContextChainWalk(Variable* var) {
   ASSERT(var->IsContextSlot());
   HInstruction* context = new HContext;
   AddInstruction(context);
-  int length = graph()->info()->scope()->ContextChainLength(var->scope());
+  int length = info()->scope()->ContextChainLength(var->scope());
   while (length-- > 0) {
     context = new HOuterContext(context);
     AddInstruction(context);
   }
   return context;
 }
 
 
 void HGraphBuilder::VisitVariableProxy(VariableProxy* expr) {
   Variable* variable = expr->AsVariable();
@@ skipping 10 matching lines @@
     }
     HValue* context = BuildContextChainWalk(variable);
     int index = variable->AsSlot()->index();
     HLoadContextSlot* instr = new HLoadContextSlot(context, index);
     ast_context()->ReturnInstruction(instr, expr->id());
   } else if (variable->is_global()) {
     LookupResult lookup;
     LookupGlobalPropertyCell(variable, &lookup, false);
     CHECK_BAILOUT;
 
-    Handle<GlobalObject> global(graph()->info()->global_object());
+    Handle<GlobalObject> global(info()->global_object());
     // TODO(3039103): Handle global property load through an IC call when access
     // checks are enabled.
     if (global->IsAccessCheckNeeded()) {
       BAILOUT("global object requires access check");
     }
     Handle<JSGlobalPropertyCell> cell(global->GetPropertyCell(&lookup));
     bool check_hole = !lookup.IsDontDelete() || lookup.IsReadOnly();
     HLoadGlobal* instr = new HLoadGlobal(cell, check_hole);
     ast_context()->ReturnInstruction(instr, expr->id());
   } else {
@@ skipping 105 matching lines @@
   }
   ast_context()->ReturnValue(Pop());
 }
 
 
 void HGraphBuilder::VisitCatchExtensionObject(CatchExtensionObject* expr) {
   BAILOUT("CatchExtensionObject");
 }
 
 
-HBasicBlock* HGraphBuilder::BuildTypeSwitch(HValue* receiver,
-                                            ZoneMapList* maps,
-                                            ZoneList<HSubgraph*>* body_graphs,
-                                            HSubgraph* default_graph,
-                                            int join_id) {
-  ASSERT(maps->length() == body_graphs->length());
-  HBasicBlock* join_block = graph()->CreateBasicBlock();
-  AddInstruction(new HCheckNonSmi(receiver));
-
-  for (int i = 0; i < maps->length(); ++i) {
-    // Build the branches, connect all the target subgraphs to the join
-    // block.  Use the default as a target of the last branch.
-    HSubgraph* if_true = body_graphs->at(i);
-    HSubgraph* if_false = (i == maps->length() - 1)
-        ? default_graph
-        : CreateBranchSubgraph(environment());
-    HCompareMap* compare =
-        new HCompareMap(receiver,
-                        maps->at(i),
-                        if_true->entry_block(),
-                        if_false->entry_block());
-    subgraph()->exit_block()->Finish(compare);
-
-    if (if_true->HasExit()) {
-      // In an effect context the value of the type switch is not needed.
-      // There is no need to merge it at the join block only to discard it.
-      if (ast_context()->IsEffect()) {
-        if_true->exit_block()->last_environment()->Drop(1);
-      }
-      if_true->exit_block()->Goto(join_block);
-    }
-
-    subgraph()->set_exit_block(if_false->exit_block());
-  }
-
-  // Connect the default if necessary.
-  if (subgraph()->HasExit()) {
-    if (ast_context()->IsEffect()) {
-      environment()->Drop(1);
-    }
-    subgraph()->exit_block()->Goto(join_block);
-  }
-
-  if (join_block->predecessors()->is_empty()) return NULL;
-  join_block->SetJoinId(join_id);
-  return join_block;
-}
-
-
 // Sets the lookup result and returns true if the store can be inlined.
 static bool ComputeStoredField(Handle<Map> type,
                                Handle<String> name,
                                LookupResult* lookup) {
   type->LookupInDescriptors(NULL, *name, lookup);
   if (!lookup->IsPropertyOrTransition()) return false;
   if (lookup->type() == FIELD) return true;
   return (lookup->type() == MAP_TRANSITION) &&
       (type->unused_property_fields() > 0);
 }
@@ skipping 75 matching lines @@
                              true)  // Needs smi and map check.
       : BuildStoreNamedGeneric(object, name, value);
 }
 
 
 void HGraphBuilder::HandlePolymorphicStoreNamedField(Assignment* expr,
                                                      HValue* object,
                                                      HValue* value,
                                                      ZoneMapList* types,
                                                      Handle<String> name) {
-  int number_of_types = Min(types->length(), kMaxStorePolymorphism);
-  ZoneMapList maps(number_of_types);
-  ZoneList<HSubgraph*> subgraphs(number_of_types);
-  bool needs_generic = (types->length() > kMaxStorePolymorphism);
-
-  // Build subgraphs for each of the specific maps.
-  //
-  // TODO(ager): We should recognize when the prototype chains for
-  // different maps are identical. In that case we can avoid
-  // repeatedly generating the same prototype map checks.
-  for (int i = 0; i < number_of_types; ++i) {
+  // TODO(ager): We should recognize when the prototype chains for different
+  // maps are identical. In that case we can avoid repeatedly generating the
+  // same prototype map checks.
+  int count = 0;
+  HBasicBlock* join = NULL;
+  for (int i = 0; i < types->length() && count < kMaxStorePolymorphism; ++i) {
     Handle<Map> map = types->at(i);
     LookupResult lookup;
     if (ComputeStoredField(map, name, &lookup)) {
-      HSubgraph* subgraph = CreateBranchSubgraph(environment());
-      SubgraphScope scope(this, subgraph);
+      if (count == 0) {
+        AddInstruction(new HCheckNonSmi(object));  // Only needed once.
+        join = graph()->CreateBasicBlock();
+      }
+      ++count;
+      HBasicBlock* if_true = graph()->CreateBasicBlock();
+      HBasicBlock* if_false = graph()->CreateBasicBlock();
+      HCompareMap* compare = new HCompareMap(object, map, if_true, if_false);
+      current_block()->Finish(compare);
+
+      set_current_block(if_true);
       HInstruction* instr =
           BuildStoreNamedField(object, name, value, map, &lookup, false);
-      Push(value);
       instr->set_position(expr->position());
+      // Goto will add the HSimulate for the store.
       AddInstruction(instr);
-      maps.Add(map);
-      subgraphs.Add(subgraph);
-    } else {
-      needs_generic = true;
+      if (!ast_context()->IsEffect()) Push(value);
+      current_block()->Goto(join);
+
+      set_current_block(if_false);
     }
   }
 
-  // If none of the properties were named fields we generate a
-  // generic store.
-  if (maps.length() == 0) {
+  // Finish up.  Unconditionally deoptimize if we've handled all the maps we
+  // know about and do not want to handle ones we've never seen.  Otherwise
+  // use a generic IC.
+  if (count == types->length() && FLAG_deoptimize_uncommon_cases) {
+    current_block()->FinishExit(new HDeoptimize);
+  } else {
     HInstruction* instr = BuildStoreNamedGeneric(object, name, value);
-    Push(value);
     instr->set_position(expr->position());
     AddInstruction(instr);
-    if (instr->HasSideEffects()) AddSimulate(expr->AssignmentId());
-    ast_context()->ReturnValue(Pop());
-  } else {
-    // Build subgraph for generic store through IC.
-    HSubgraph* default_graph = CreateBranchSubgraph(environment());
-    { SubgraphScope scope(this, default_graph);
-      if (!needs_generic && FLAG_deoptimize_uncommon_cases) {
-        default_graph->FinishExit(new HDeoptimize());
-      } else {
-        HInstruction* instr = BuildStoreNamedGeneric(object, name, value);
-        Push(value);
-        instr->set_position(expr->position());
-        AddInstruction(instr);
+
+    if (join != NULL) {
+      if (!ast_context()->IsEffect()) Push(value);
+      current_block()->Goto(join);
+    } else {
+      // The HSimulate for the store should not see the stored value in
+      // effect contexts (it is not materialized at expr->id() in the
+      // unoptimized code).
+      if (instr->HasSideEffects()) {
+        if (ast_context()->IsEffect()) {
+          AddSimulate(expr->id());
+        } else {
+          Push(value);
+          AddSimulate(expr->id());
+          Drop(1);
+        }
       }
-    }
-
-    HBasicBlock* new_exit_block =
-        BuildTypeSwitch(object, &maps, &subgraphs, default_graph, expr->id());
-    subgraph()->set_exit_block(new_exit_block);
-    // In an effect context, we did not materialized the value in the
-    // predecessor environments so there's no need to handle it here.
-    if (subgraph()->HasExit() && !ast_context()->IsEffect()) {
-      ast_context()->ReturnValue(Pop());
+      ast_context()->ReturnValue(value);
+      return;
     }
   }
+
+  ASSERT(join != NULL);
+  join->SetJoinId(expr->id());
+  set_current_block(join);
+  if (!ast_context()->IsEffect()) ast_context()->ReturnValue(Pop());
 }
 
 
 void HGraphBuilder::HandlePropertyAssignment(Assignment* expr) {
   Property* prop = expr->target()->AsProperty();
   ASSERT(prop != NULL);
   expr->RecordTypeFeedback(oracle());
   VISIT_FOR_VALUE(prop->obj());
 
   HValue* value = NULL;
@@ skipping 24 matching lines @@
     }
 
   } else {
     // Keyed store.
     VISIT_FOR_VALUE(prop->key());
     VISIT_FOR_VALUE(expr->value());
     value = Pop();
     HValue* key = Pop();
     HValue* object = Pop();
 
-    bool is_fast_elements = expr->IsMonomorphic() &&
-        expr->GetMonomorphicReceiverType()->has_fast_elements();
-
-    instr = is_fast_elements
-        ? BuildStoreKeyedFastElement(object, key, value, expr)
-        : BuildStoreKeyedGeneric(object, key, value);
+    if (expr->IsMonomorphic()) {
+      Handle<Map> receiver_type(expr->GetMonomorphicReceiverType());
+      // An object has either fast elements or external array elements, but
+      // never both. Pixel array maps that are assigned to pixel array elements
+      // are always created with the fast elements flag cleared.
+      if (receiver_type->has_external_array_elements()) {
+        if (expr->GetExternalArrayType() == kExternalPixelArray) {
+          instr = BuildStoreKeyedPixelArrayElement(object, key, value, expr);
+        }
+      } else if (receiver_type->has_fast_elements()) {
+        instr = BuildStoreKeyedFastElement(object, key, value, expr);
+      }
+    }
+    if (instr == NULL) {
+      instr = BuildStoreKeyedGeneric(object, key, value);
+    }
   }
 
   Push(value);
   instr->set_position(expr->position());
   AddInstruction(instr);
   if (instr->HasSideEffects()) AddSimulate(expr->AssignmentId());
   ast_context()->ReturnValue(Pop());
 }
 
 
 // Because not every expression has a position and there is not common
 // superclass of Assignment and CountOperation, we cannot just pass the
 // owning expression instead of position and ast_id separately.
 void HGraphBuilder::HandleGlobalVariableAssignment(Variable* var,
                                                    HValue* value,
                                                    int position,
                                                    int ast_id) {
   LookupResult lookup;
   LookupGlobalPropertyCell(var, &lookup, true);
   CHECK_BAILOUT;
 
   bool check_hole = !lookup.IsDontDelete() || lookup.IsReadOnly();
-  Handle<GlobalObject> global(graph()->info()->global_object());
+  Handle<GlobalObject> global(info()->global_object());
   Handle<JSGlobalPropertyCell> cell(global->GetPropertyCell(&lookup));
   HInstruction* instr = new HStoreGlobal(value, cell, check_hole);
   instr->set_position(position);
   AddInstruction(instr);
   if (instr->HasSideEffects()) AddSimulate(ast_id);
 }
 
 
 void HGraphBuilder::HandleCompoundAssignment(Assignment* expr) {
   Expression* target = expr->target();
@@ skipping 168 matching lines @@
   // assignments, count operations, or for-in.  Consequently throw can
   // currently only occur in an effect context.
   ASSERT(ast_context()->IsEffect());
   VISIT_FOR_VALUE(expr->exception());
 
   HValue* value = environment()->Pop();
   HThrow* instr = new HThrow(value);
   instr->set_position(expr->position());
   AddInstruction(instr);
   AddSimulate(expr->id());
-  current_subgraph_->FinishExit(new HAbnormalExit);
+  current_block()->FinishExit(new HAbnormalExit);
+  set_current_block(NULL);
 }
 
 
 void HGraphBuilder::HandlePolymorphicLoadNamedField(Property* expr,
                                                     HValue* object,
                                                     ZoneMapList* types,
                                                     Handle<String> name) {
-  int number_of_types = Min(types->length(), kMaxLoadPolymorphism);
-  ZoneMapList maps(number_of_types);
-  ZoneList<HSubgraph*> subgraphs(number_of_types);
-  bool needs_generic = (types->length() > kMaxLoadPolymorphism);
-
-  // Build subgraphs for each of the specific maps.
-  //
-  // TODO(ager): We should recognize when the prototype chains for
-  // different maps are identical. In that case we can avoid
-  // repeatedly generating the same prototype map checks.
-  for (int i = 0; i < number_of_types; ++i) {
+  // TODO(ager): We should recognize when the prototype chains for different
+  // maps are identical. In that case we can avoid repeatedly generating the
+  // same prototype map checks.
+  int count = 0;
+  HBasicBlock* join = NULL;
+  for (int i = 0; i < types->length() && count < kMaxLoadPolymorphism; ++i) {
     Handle<Map> map = types->at(i);
     LookupResult lookup;
     map->LookupInDescriptors(NULL, *name, &lookup);
     if (lookup.IsProperty() && lookup.type() == FIELD) {
-      HSubgraph* subgraph = CreateBranchSubgraph(environment());
-      SubgraphScope scope(this, subgraph);
+      if (count == 0) {
+        AddInstruction(new HCheckNonSmi(object));  // Only needed once.
+        join = graph()->CreateBasicBlock();
+      }
+      ++count;
+      HBasicBlock* if_true = graph()->CreateBasicBlock();
+      HBasicBlock* if_false = graph()->CreateBasicBlock();
+      HCompareMap* compare = new HCompareMap(object, map, if_true, if_false);
+      current_block()->Finish(compare);
+
+      set_current_block(if_true);
       HLoadNamedField* instr =
           BuildLoadNamedField(object, expr, map, &lookup, false);
       instr->set_position(expr->position());
-      instr->ClearFlag(HValue::kUseGVN);  // Don't do GVN on polymorphic loads.
-      PushAndAdd(instr);
-      maps.Add(map);
-      subgraphs.Add(subgraph);
-    } else {
-      needs_generic = true;
+      instr->ClearFlag(HValue::kUseGVN);
+      AddInstruction(instr);
+      if (!ast_context()->IsEffect()) Push(instr);
+      current_block()->Goto(join);
+
+      set_current_block(if_false);
     }
   }
 
-  // If none of the properties were named fields we generate a
-  // generic load.
-  if (maps.length() == 0) {
+  // Finish up.  Unconditionally deoptimize if we've handled all the maps we
+  // know about and do not want to handle ones we've never seen.  Otherwise
+  // use a generic IC.
+  if (count == types->length() && FLAG_deoptimize_uncommon_cases) {
+    current_block()->FinishExit(new HDeoptimize);
+  } else {
     HInstruction* instr = BuildLoadNamedGeneric(object, expr);
     instr->set_position(expr->position());
-    ast_context()->ReturnInstruction(instr, expr->id());
-  } else {
-    // Build subgraph for generic load through IC.
-    HSubgraph* default_graph = CreateBranchSubgraph(environment());
-    { SubgraphScope scope(this, default_graph);
-      if (!needs_generic && FLAG_deoptimize_uncommon_cases) {
-        default_graph->FinishExit(new HDeoptimize());
-      } else {
-        HInstruction* instr = BuildLoadNamedGeneric(object, expr);
-        instr->set_position(expr->position());
-        PushAndAdd(instr);
-      }
-    }
 
-    HBasicBlock* new_exit_block =
-        BuildTypeSwitch(object, &maps, &subgraphs, default_graph, expr->id());
-    subgraph()->set_exit_block(new_exit_block);
-    // In an effect context, we did not materialized the value in the
-    // predecessor environments so there's no need to handle it here.
-    if (subgraph()->HasExit() && !ast_context()->IsEffect()) {
-      ast_context()->ReturnValue(Pop());
+    if (join != NULL) {
+      AddInstruction(instr);
+      if (!ast_context()->IsEffect()) Push(instr);
+      current_block()->Goto(join);
+    } else {
+      ast_context()->ReturnInstruction(instr, expr->id());
+      return;
     }
   }
+
+  ASSERT(join != NULL);
+  join->SetJoinId(expr->id());
+  set_current_block(join);
+  if (!ast_context()->IsEffect()) ast_context()->ReturnValue(Pop());
 }
 
 
 HLoadNamedField* HGraphBuilder::BuildLoadNamedField(HValue* object,
                                                     Property* expr,
                                                     Handle<Map> type,
                                                     LookupResult* lookup,
                                                     bool smi_and_map_check) {
   if (smi_and_map_check) {
     AddInstruction(new HCheckNonSmi(object));
@@ skipping 79 matching lines @@
 }
 
 
 HInstruction* HGraphBuilder::BuildLoadKeyedPixelArrayElement(HValue* object,
                                                              HValue* key,
                                                              Property* expr) {
   ASSERT(!expr->key()->IsPropertyName() && expr->IsMonomorphic());
   AddInstruction(new HCheckNonSmi(object));
   Handle<Map> map = expr->GetMonomorphicReceiverType();
   ASSERT(!map->has_fast_elements());
-  ASSERT(map->has_pixel_array_elements());
+  ASSERT(map->has_external_array_elements());
   AddInstruction(new HCheckMap(object, map));
   HLoadElements* elements = new HLoadElements(object);
   AddInstruction(elements);
-  HInstruction* length = AddInstruction(new HPixelArrayLength(elements));
+  HInstruction* length = new HExternalArrayLength(elements);
+  AddInstruction(length);
   AddInstruction(new HBoundsCheck(key, length));
-  HLoadPixelArrayExternalPointer* external_elements =
-      new HLoadPixelArrayExternalPointer(elements);
+  HLoadExternalArrayPointer* external_elements =
+      new HLoadExternalArrayPointer(elements);
   AddInstruction(external_elements);
   HLoadPixelArrayElement* pixel_array_value =
       new HLoadPixelArrayElement(external_elements, key);
   return pixel_array_value;
 }
 
 
 HInstruction* HGraphBuilder::BuildStoreKeyedGeneric(HValue* object,
                                                     HValue* key,
                                                     HValue* value) {
@@ skipping 19 matching lines @@
   if (is_array) {
     length = AddInstruction(new HJSArrayLength(object));
   } else {
     length = AddInstruction(new HFixedArrayLength(elements));
   }
   AddInstruction(new HBoundsCheck(key, length));
   return new HStoreKeyedFastElement(elements, key, val);
 }
 
 
+HInstruction* HGraphBuilder::BuildStoreKeyedPixelArrayElement(
+    HValue* object,
+    HValue* key,
+    HValue* val,
+    Expression* expr) {
+  ASSERT(expr->IsMonomorphic());
+  AddInstruction(new HCheckNonSmi(object));
+  Handle<Map> map = expr->GetMonomorphicReceiverType();
+  ASSERT(!map->has_fast_elements());
+  ASSERT(map->has_external_array_elements());
+  AddInstruction(new HCheckMap(object, map));
+  HLoadElements* elements = new HLoadElements(object);
+  AddInstruction(elements);
+  HInstruction* length = AddInstruction(new HExternalArrayLength(elements));
+  AddInstruction(new HBoundsCheck(key, length));
+  HLoadExternalArrayPointer* external_elements =
+      new HLoadExternalArrayPointer(elements);
+  AddInstruction(external_elements);
+  return new HStorePixelArrayElement(external_elements, key, val);
+}
+
+
 bool HGraphBuilder::TryArgumentsAccess(Property* expr) {
   VariableProxy* proxy = expr->obj()->AsVariableProxy();
   if (proxy == NULL) return false;
   if (!proxy->var()->IsStackAllocated()) return false;
   if (!environment()->Lookup(proxy->var())->CheckFlag(HValue::kIsArguments)) {
     return false;
   }
 
   HInstruction* result = NULL;
   if (expr->key()->IsPropertyName()) {
     Handle<String> name = expr->key()->AsLiteral()->AsPropertyName();
     if (!name->IsEqualTo(CStrVector("length"))) return false;
     HInstruction* elements = AddInstruction(new HArgumentsElements);
     result = new HArgumentsLength(elements);
   } else {
+    Push(graph()->GetArgumentsObject());
     VisitForValue(expr->key());
     if (HasStackOverflow()) return false;
     HValue* key = Pop();
+    Drop(1);  // Arguments object.
     HInstruction* elements = AddInstruction(new HArgumentsElements);
     HInstruction* length = AddInstruction(new HArgumentsLength(elements));
     AddInstruction(new HBoundsCheck(key, length));
     result = new HAccessArgumentsAt(elements, length, key);
   }
   ast_context()->ReturnInstruction(result, expr->id());
   return true;
 }
 
 
@@ skipping 12 matching lines @@
     AddInstruction(new HCheckInstanceType(array, JS_ARRAY_TYPE, JS_ARRAY_TYPE));
     instr = new HJSArrayLength(array);
 
   } else if (expr->IsStringLength()) {
     HValue* string = Pop();
     AddInstruction(new HCheckNonSmi(string));
     AddInstruction(new HCheckInstanceType(string,
                                           FIRST_STRING_TYPE,
                                           LAST_STRING_TYPE));
     instr = new HStringLength(string);
+  } else if (expr->IsStringAccess()) {
+    VISIT_FOR_VALUE(expr->key());
+    HValue* index = Pop();
+    HValue* string = Pop();
+    HStringCharCodeAt* char_code = BuildStringCharCodeAt(string, index);
+    AddInstruction(char_code);
+    instr = new HStringCharFromCode(char_code);
 
   } else if (expr->IsFunctionPrototype()) {
     HValue* function = Pop();
     AddInstruction(new HCheckNonSmi(function));
     instr = new HLoadFunctionPrototype(function);
 
   } else if (expr->key()->IsPropertyName()) {
     Handle<String> name = expr->key()->AsLiteral()->AsPropertyName();
     ZoneMapList* types = expr->GetReceiverTypes();
 
@@ skipping 12 matching lines @@
     VISIT_FOR_VALUE(expr->key());
 
     HValue* key = Pop();
     HValue* obj = Pop();
 
     if (expr->IsMonomorphic()) {
       Handle<Map> receiver_type(expr->GetMonomorphicReceiverType());
       // An object has either fast elements or pixel array elements, but never
       // both. Pixel array maps that are assigned to pixel array elements are
       // always created with the fast elements flag cleared.
-      if (receiver_type->has_pixel_array_elements()) {
-        instr = BuildLoadKeyedPixelArrayElement(obj, key, expr);
+      if (receiver_type->has_external_array_elements()) {
+        if (expr->GetExternalArrayType() == kExternalPixelArray) {
+          instr = BuildLoadKeyedPixelArrayElement(obj, key, expr);
+        }
       } else if (receiver_type->has_fast_elements()) {
         instr = BuildLoadKeyedFastElement(obj, key, expr);
       }
     }
     if (instr == NULL) {
       instr = BuildLoadKeyedGeneric(obj, key);
     }
   }
   instr->set_position(expr->position());
   ast_context()->ReturnInstruction(instr, expr->id());
@@ skipping 16 matching lines @@
         Handle<JSObject>(JSObject::cast(receiver_map->prototype())),
         expr->holder()));
   }
 }
 
 
 void HGraphBuilder::HandlePolymorphicCallNamed(Call* expr,
                                                HValue* receiver,
                                                ZoneMapList* types,
                                                Handle<String> name) {
-  int argument_count = expr->arguments()->length() + 1;  // Plus receiver.
-  int number_of_types = Min(types->length(), kMaxCallPolymorphism);
-  ZoneMapList maps(number_of_types);
-  ZoneList<HSubgraph*> subgraphs(number_of_types);
-  bool needs_generic = (types->length() > kMaxCallPolymorphism);
-
-  // Build subgraphs for each of the specific maps.
-  //
   // TODO(ager): We should recognize when the prototype chains for different
   // maps are identical. In that case we can avoid repeatedly generating the
   // same prototype map checks.
-  for (int i = 0; i < number_of_types; ++i) {
+  int argument_count = expr->arguments()->length() + 1;  // Includes receiver.
+  int count = 0;
+  HBasicBlock* join = NULL;
+  for (int i = 0; i < types->length() && count < kMaxCallPolymorphism; ++i) {
     Handle<Map> map = types->at(i);
     if (expr->ComputeTarget(map, name)) {
-      HSubgraph* subgraph = CreateBranchSubgraph(environment());
-      SubgraphScope scope(this, subgraph);
+      if (count == 0) {
+        AddInstruction(new HCheckNonSmi(receiver));  // Only needed once.
+        join = graph()->CreateBasicBlock();
+      }
+      ++count;
+      HBasicBlock* if_true = graph()->CreateBasicBlock();
+      HBasicBlock* if_false = graph()->CreateBasicBlock();
+      HCompareMap* compare = new HCompareMap(receiver, map, if_true, if_false);
+      current_block()->Finish(compare);
+
+      set_current_block(if_true);
       AddCheckConstantFunction(expr, receiver, map, false);
       if (FLAG_trace_inlining && FLAG_polymorphic_inlining) {
         PrintF("Trying to inline the polymorphic call to %s\n",
                *name->ToCString());
       }
       if (!FLAG_polymorphic_inlining || !TryInline(expr)) {
         // Check for bailout, as trying to inline might fail due to bailout
         // during hydrogen processing.
         CHECK_BAILOUT;
-        HCall* call = new HCallConstantFunction(expr->target(), argument_count);
+        HCallConstantFunction* call =
+            new HCallConstantFunction(expr->target(), argument_count);
         call->set_position(expr->position());
         PreProcessCall(call);
-        PushAndAdd(call);
+        AddInstruction(call);
+        if (!ast_context()->IsEffect()) Push(call);
       }
-      maps.Add(map);
-      subgraphs.Add(subgraph);
-    } else {
-      needs_generic = true;
+
+      if (current_block() != NULL) current_block()->Goto(join);
+      set_current_block(if_false);
     }
   }
 
-  // If we couldn't compute the target for any of the maps just perform an
-  // IC call.
-  if (maps.length() == 0) {
+  // Finish up.  Unconditionally deoptimize if we've handled all the maps we
+  // know about and do not want to handle ones we've never seen.  Otherwise
+  // use a generic IC.
+  if (count == types->length() && FLAG_deoptimize_uncommon_cases) {
+    current_block()->FinishExit(new HDeoptimize);
+  } else {
     HContext* context = new HContext;
     AddInstruction(context);
-    HCall* call = new HCallNamed(context, name, argument_count);
+    HCallNamed* call = new HCallNamed(context, name, argument_count);
     call->set_position(expr->position());
     PreProcessCall(call);
-    ast_context()->ReturnInstruction(call, expr->id());
-  } else {
-    // Build subgraph for generic call through IC.
-    HSubgraph* default_graph = CreateBranchSubgraph(environment());
-    { SubgraphScope scope(this, default_graph);
-      if (!needs_generic && FLAG_deoptimize_uncommon_cases) {
-        default_graph->FinishExit(new HDeoptimize());
-      } else {
-        HContext* context = new HContext;
-        AddInstruction(context);
-        HCall* call = new HCallNamed(context, name, argument_count);
-        call->set_position(expr->position());
-        PreProcessCall(call);
-        PushAndAdd(call);
-      }
+
+    if (join != NULL) {
+      AddInstruction(call);
+      if (!ast_context()->IsEffect()) Push(call);
+      current_block()->Goto(join);
+    } else {
+      ast_context()->ReturnInstruction(call, expr->id());
+      return;
     }
+  }
 
-    HBasicBlock* new_exit_block =
-        BuildTypeSwitch(receiver, &maps, &subgraphs, default_graph, expr->id());
-    subgraph()->set_exit_block(new_exit_block);
-    // In an effect context, we did not materialized the value in the
-    // predecessor environments so there's no need to handle it here.
-    if (new_exit_block != NULL && !ast_context()->IsEffect()) {
-      ast_context()->ReturnValue(Pop());
+  // We assume that control flow is always live after an expression.  So
+  // even without predecessors to the join block, we set it as the exit
+  // block and continue by adding instructions there.
+  ASSERT(join != NULL);
+  set_current_block(join);
+  if (join->HasPredecessor()) {
+    join->SetJoinId(expr->id());
+    if (!ast_context()->IsEffect()) ast_context()->ReturnValue(Pop());
+  }
+}
+
+
+void HGraphBuilder::TraceInline(Handle<JSFunction> target, const char* reason) {
+  if (FLAG_trace_inlining) {
+    SmartPointer<char> callee = target->shared()->DebugName()->ToCString();
+    SmartPointer<char> caller =
+        info()->function()->debug_name()->ToCString();
+    if (reason == NULL) {
+      PrintF("Inlined %s called from %s.\n", *callee, *caller);
+    } else {
+      PrintF("Did not inline %s called from %s (%s).\n",
+             *callee, *caller, reason);
     }
   }
 }
 
-
-void HGraphBuilder::TraceInline(Handle<JSFunction> target, bool result) {
-  SmartPointer<char> callee = target->shared()->DebugName()->ToCString();
-  SmartPointer<char> caller =
-      graph()->info()->function()->debug_name()->ToCString();
-  if (result) {
-    PrintF("Inlined %s called from %s.\n", *callee, *caller);
-  } else {
-    PrintF("Do not inline %s called from %s.\n", *callee, *caller);
-  }
-}
-
 
 bool HGraphBuilder::TryInline(Call* expr) {
   if (!FLAG_use_inlining) return false;
 
   // Precondition: call is monomorphic and we have found a target with the
   // appropriate arity.
   Handle<JSFunction> target = expr->target();
 
   // Do a quick check on source code length to avoid parsing large
   // inlining candidates.
   if (FLAG_limit_inlining && target->shared()->SourceSize() > kMaxSourceSize) {
-    if (FLAG_trace_inlining) TraceInline(target, false);
+    TraceInline(target, "target text too big");
     return false;
   }
 
   // Target must be inlineable.
-  if (!target->IsInlineable()) return false;
+  if (!target->IsInlineable()) {
+    TraceInline(target, "target not inlineable");
+    return false;
+  }
 
   // No context change required.
-  CompilationInfo* outer_info = graph()->info();
+  CompilationInfo* outer_info = info();
   if (target->context() != outer_info->closure()->context() ||
       outer_info->scope()->contains_with() ||
       outer_info->scope()->num_heap_slots() > 0) {
+    TraceInline(target, "target requires context change");
     return false;
   }
 
   // Don't inline deeper than two calls.
   HEnvironment* env = environment();
-  if (env->outer() != NULL && env->outer()->outer() != NULL) return false;
+  if (env->outer() != NULL && env->outer()->outer() != NULL) {
+    TraceInline(target, "inline depth limit reached");
+    return false;
+  }
 
   // Don't inline recursive functions.
-  if (target->shared() == outer_info->closure()->shared()) return false;
+  if (target->shared() == outer_info->closure()->shared()) {
+    TraceInline(target, "target is recursive");
+    return false;
+  }
 
   // We don't want to add more than a certain number of nodes from inlining.
   if (FLAG_limit_inlining && inlined_count_ > kMaxInlinedNodes) {
-    if (FLAG_trace_inlining) TraceInline(target, false);
+    TraceInline(target, "cumulative AST node limit reached");
     return false;
   }
 
   int count_before = AstNode::Count();
 
   // Parse and allocate variables.
-  CompilationInfo inner_info(target);
-  if (!ParserApi::Parse(&inner_info) ||
-      !Scope::Analyze(&inner_info)) {
+  CompilationInfo target_info(target);
+  if (!ParserApi::Parse(&target_info) ||
+      !Scope::Analyze(&target_info)) {
     if (Top::has_pending_exception()) {
+      // Parse or scope error, never optimize this function.
       SetStackOverflow();
+      target->shared()->set_optimization_disabled(true);
     }
+    TraceInline(target, "parse failure");
     return false;
   }
-  FunctionLiteral* function = inner_info.function();
+
+  if (target_info.scope()->num_heap_slots() > 0) {
+    TraceInline(target, "target has context-allocated variables");
+    return false;
+  }
+  FunctionLiteral* function = target_info.function();
 
   // Count the number of AST nodes added by inlining this call.
   int nodes_added = AstNode::Count() - count_before;
   if (FLAG_limit_inlining && nodes_added > kMaxInlinedSize) {
-    if (FLAG_trace_inlining) TraceInline(target, false);
+    TraceInline(target, "target AST is too large");
     return false;
   }
 
   // Check if we can handle all declarations in the inlined functions.
-  VisitDeclarations(inner_info.scope()->declarations());
+  VisitDeclarations(target_info.scope()->declarations());
   if (HasStackOverflow()) {
+    TraceInline(target, "target has non-trivial declaration");
     ClearStackOverflow();
     return false;
   }
 
   // Don't inline functions that uses the arguments object or that
   // have a mismatching number of parameters.
-  Handle<SharedFunctionInfo> shared(target->shared());
+  Handle<SharedFunctionInfo> target_shared(target->shared());
   int arity = expr->arguments()->length();
   if (function->scope()->arguments() != NULL ||
-      arity != shared->formal_parameter_count()) {
+      arity != target_shared->formal_parameter_count()) {
+    TraceInline(target, "target requires special argument handling");
     return false;
   }
 
   // All statements in the body must be inlineable.
   for (int i = 0, count = function->body()->length(); i < count; ++i) {
-    if (!function->body()->at(i)->IsInlineable()) return false;
+    if (!function->body()->at(i)->IsInlineable()) {
+      TraceInline(target, "target contains unsupported syntax");
+      return false;
+    }
   }
 
   // Generate the deoptimization data for the unoptimized version of
   // the target function if we don't already have it.
-  if (!shared->has_deoptimization_support()) {
+  if (!target_shared->has_deoptimization_support()) {
     // Note that we compile here using the same AST that we will use for
     // generating the optimized inline code.
-    inner_info.EnableDeoptimizationSupport();
-    if (!FullCodeGenerator::MakeCode(&inner_info)) return false;
-    shared->EnableDeoptimizationSupport(*inner_info.code());
-    Compiler::RecordFunctionCompilation(
-        Logger::FUNCTION_TAG,
-        Handle<String>(shared->DebugName()),
-        shared->start_position(),
-        &inner_info);
+    target_info.EnableDeoptimizationSupport();
+    if (!FullCodeGenerator::MakeCode(&target_info)) {
+      TraceInline(target, "could not generate deoptimization info");
+      return false;
+    }
+    target_shared->EnableDeoptimizationSupport(*target_info.code());
+    Compiler::RecordFunctionCompilation(Logger::FUNCTION_TAG,
+                                        &target_info,
+                                        target_shared);
   }
 
+  // ----------------------------------------------------------------
   // Save the pending call context and type feedback oracle. Set up new ones
   // for the inlined function.
-  ASSERT(shared->has_deoptimization_support());
-  AstContext* saved_call_context = call_context();
-  HBasicBlock* saved_function_return = function_return();
-  TypeFeedbackOracle* saved_oracle = oracle();
-  // On-stack replacement cannot target inlined functions.  Since we don't
-  // use a separate CompilationInfo structure for the inlined function, we
-  // save and restore the AST ID in the original compilation info.
-  int saved_osr_ast_id = graph()->info()->osr_ast_id();
+  ASSERT(target_shared->has_deoptimization_support());
+  TypeFeedbackOracle target_oracle(
+      Handle<Code>(target_shared->code()),
+      Handle<Context>(target->context()->global_context()));
+  FunctionState target_state(this, &target_info, &target_oracle);
 
-  TestContext* test_context = NULL;
-  if (ast_context()->IsTest()) {
-    // Inlined body is treated as if it occurs in an 'inlined' call context
-    // with true and false blocks that will forward to the real ones.
-    HBasicBlock* if_true = graph()->CreateBasicBlock();
-    HBasicBlock* if_false = graph()->CreateBasicBlock();
-    if_true->MarkAsInlineReturnTarget();
-    if_false->MarkAsInlineReturnTarget();
-    // AstContext constructor pushes on the context stack.
-    test_context = new TestContext(this, if_true, if_false);
-    function_return_ = NULL;
-  } else {
-    // Inlined body is treated as if it occurs in the original call context.
-    function_return_ = graph()->CreateBasicBlock();
-    function_return_->MarkAsInlineReturnTarget();
-  }
-  call_context_ = ast_context();
-  TypeFeedbackOracle new_oracle(
-      Handle<Code>(shared->code()),
-      Handle<Context>(target->context()->global_context()));
-  oracle_ = &new_oracle;
-  graph()->info()->SetOsrAstId(AstNode::kNoNumber);
+  HConstant* undefined = graph()->GetConstantUndefined();
+  HEnvironment* inner_env =
+      environment()->CopyForInlining(target, function, true, undefined);
+  HBasicBlock* body_entry = CreateBasicBlock(inner_env);
+  current_block()->Goto(body_entry);
 
-  HSubgraph* body = CreateInlinedSubgraph(env, target, function);
-  body->exit_block()->AddInstruction(new HEnterInlined(target, function));
-  AddToSubgraph(body, function->body());
+  body_entry->SetJoinId(expr->ReturnId());
+  set_current_block(body_entry);
+  AddInstruction(new HEnterInlined(target, function));
+  VisitStatements(function->body());
   if (HasStackOverflow()) {
     // Bail out if the inline function did, as we cannot residualize a call
     // instead.
-    delete test_context;
-    call_context_ = saved_call_context;
-    function_return_ = saved_function_return;
-    oracle_ = saved_oracle;
-    graph()->info()->SetOsrAstId(saved_osr_ast_id);
+    TraceInline(target, "inline graph construction failed");
     return false;
   }
 
   // Update inlined nodes count.
   inlined_count_ += nodes_added;
 
-  if (FLAG_trace_inlining) TraceInline(target, true);
+  TraceInline(target, NULL);
 
-  if (body->HasExit()) {
+  if (current_block() != NULL) {
     // Add a return of undefined if control can fall off the body.  In a
     // test context, undefined is false.
-    HValue* return_value = graph()->GetConstantUndefined();
-    if (test_context == NULL) {
-      ASSERT(function_return_ != NULL);
-      body->exit_block()->AddLeaveInlined(return_value, function_return_);
+    if (inlined_test_context() == NULL) {
+      ASSERT(function_return() != NULL);
+      ASSERT(call_context()->IsEffect() || call_context()->IsValue());
+      if (call_context()->IsEffect()) {
+        current_block()->Goto(function_return(), false);
+      } else {
+        current_block()->AddLeaveInlined(undefined, function_return());
+      }
     } else {
       // The graph builder assumes control can reach both branches of a
       // test, so we materialize the undefined value and test it rather than
       // simply jumping to the false target.
       //
       // TODO(3168478): refactor to avoid this.
       HBasicBlock* empty_true = graph()->CreateBasicBlock();
       HBasicBlock* empty_false = graph()->CreateBasicBlock();
-      HTest* test = new HTest(return_value, empty_true, empty_false);
-      body->exit_block()->Finish(test);
+      HTest* test = new HTest(undefined, empty_true, empty_false);
+      current_block()->Finish(test);
 
-      HValue* const no_return_value = NULL;
-      empty_true->AddLeaveInlined(no_return_value, test_context->if_true());
-      empty_false->AddLeaveInlined(no_return_value, test_context->if_false());
+      empty_true->Goto(inlined_test_context()->if_true(), false);
+      empty_false->Goto(inlined_test_context()->if_false(), false);
     }
-    body->set_exit_block(NULL);
   }
 
-  // Record the environment at the inlined function call.
-  AddSimulate(expr->ReturnId());
-
-  // Jump to the function entry (without re-recording the environment).
-  subgraph()->exit_block()->Finish(new HGoto(body->entry_block()));
-
   // Fix up the function exits.
-  if (test_context != NULL) {
-    HBasicBlock* if_true = test_context->if_true();
-    HBasicBlock* if_false = test_context->if_false();
+  if (inlined_test_context() != NULL) {
+    HBasicBlock* if_true = inlined_test_context()->if_true();
+    HBasicBlock* if_false = inlined_test_context()->if_false();
     if_true->SetJoinId(expr->id());
     if_false->SetJoinId(expr->id());
-    ASSERT(ast_context() == test_context);
-    delete test_context;  // Destructor pops from expression context stack.
+    ASSERT(ast_context() == inlined_test_context());
+    // Pop the return test context from the expression context stack.
+    ClearInlinedTestContext();
 
     // Forward to the real test context.
-    HValue* const no_return_value = NULL;
     HBasicBlock* true_target = TestContext::cast(ast_context())->if_true();
-    if (true_target->IsInlineReturnTarget()) {
-      if_true->AddLeaveInlined(no_return_value, true_target);
-    } else {
-      if_true->Goto(true_target);
-    }
-
     HBasicBlock* false_target = TestContext::cast(ast_context())->if_false();
-    if (false_target->IsInlineReturnTarget()) {
-      if_false->AddLeaveInlined(no_return_value, false_target);
-    } else {
-      if_false->Goto(false_target);
-    }
+    if_true->Goto(true_target, false);
+    if_false->Goto(false_target, false);
 
     // TODO(kmillikin): Come up with a better way to handle this. It is too
     // subtle. NULL here indicates that the enclosing context has no control
     // flow to handle.
-    subgraph()->set_exit_block(NULL);
+    set_current_block(NULL);
 
   } else {
-    function_return_->SetJoinId(expr->id());
-    subgraph()->set_exit_block(function_return_);
+    function_return()->SetJoinId(expr->id());
+    set_current_block(function_return());
   }
 
-  call_context_ = saved_call_context;
-  function_return_ = saved_function_return;
-  oracle_ = saved_oracle;
-  graph()->info()->SetOsrAstId(saved_osr_ast_id);
-
   return true;
 }
 
 
-void HBasicBlock::AddLeaveInlined(HValue* return_value, HBasicBlock* target) {
-  ASSERT(target->IsInlineReturnTarget());
-  AddInstruction(new HLeaveInlined);
-  HEnvironment* outer = last_environment()->outer();
-  if (return_value != NULL) outer->Push(return_value);
-  UpdateEnvironment(outer);
-  Goto(target);
-}
-
-
 bool HGraphBuilder::TryInlineBuiltinFunction(Call* expr,
                                              HValue* receiver,
                                              Handle<Map> receiver_map,
                                              CheckType check_type) {
   ASSERT(check_type != RECEIVER_MAP_CHECK || !receiver_map.is_null());
   // Try to inline calls like Math.* as operations in the calling function.
   if (!expr->target()->shared()->HasBuiltinFunctionId()) return false;
   BuiltinFunctionId id = expr->target()->shared()->builtin_function_id();
   int argument_count = expr->arguments()->length() + 1;  // Plus receiver.
   switch (id) {
     case kStringCharCodeAt:
+    case kStringCharAt:
       if (argument_count == 2 && check_type == STRING_CHECK) {
         HValue* index = Pop();
         HValue* string = Pop();
         ASSERT(!expr->holder().is_null());
         AddInstruction(new HCheckPrototypeMaps(
             oracle()->GetPrototypeForPrimitiveCheck(STRING_CHECK),
             expr->holder()));
-        HStringCharCodeAt* result = BuildStringCharCodeAt(string, index);
+        HStringCharCodeAt* char_code = BuildStringCharCodeAt(string, index);
+        if (id == kStringCharCodeAt) {
+          ast_context()->ReturnInstruction(char_code, expr->id());
+          return true;
+        }
+        AddInstruction(char_code);
+        HStringCharFromCode* result = new HStringCharFromCode(char_code);
         ast_context()->ReturnInstruction(result, expr->id());
         return true;
       }
       break;
     case kMathRound:
     case kMathFloor:
     case kMathAbs:
     case kMathSqrt:
     case kMathLog:
     case kMathSin:
@@ skipping 54 matching lines @@
   }
   return false;
 }
 
 
 bool HGraphBuilder::TryCallApply(Call* expr) {
   Expression* callee = expr->expression();
   Property* prop = callee->AsProperty();
   ASSERT(prop != NULL);
 
-  if (graph()->info()->scope()->arguments() == NULL) return false;
+  if (info()->scope()->arguments() == NULL) return false;
 
   Handle<String> name = prop->key()->AsLiteral()->AsPropertyName();
   if (!name->IsEqualTo(CStrVector("apply"))) return false;
 
   ZoneList<Expression*>* args = expr->arguments();
   if (args->length() != 2) return false;
 
   VariableProxy* arg_two = args->at(1)->AsVariableProxy();
   if (arg_two == NULL || !arg_two->var()->IsStackAllocated()) return false;
   HValue* arg_two_value = environment()->Lookup(arg_two->var());
@@ skipping 26 matching lines @@
 static bool HasCustomCallGenerator(Handle<JSFunction> function) {
   SharedFunctionInfo* info = function->shared();
   return info->HasBuiltinFunctionId() &&
       CallStubCompiler::HasCustomCallGenerator(info->builtin_function_id());
 }
 
 
 void HGraphBuilder::VisitCall(Call* expr) {
   Expression* callee = expr->expression();
   int argument_count = expr->arguments()->length() + 1;  // Plus receiver.
-  HCall* call = NULL;
+  HInstruction* call = NULL;
 
   Property* prop = callee->AsProperty();
   if (prop != NULL) {
     if (!prop->key()->IsPropertyName()) {
       // Keyed function call.
-      VisitArgument(prop->obj());
-      CHECK_BAILOUT;
+      VISIT_FOR_VALUE(prop->obj());
 
       VISIT_FOR_VALUE(prop->key());
       // Push receiver and key like the non-optimized code generator expects it.
       HValue* key = Pop();
       HValue* receiver = Pop();
       Push(key);
       Push(receiver);
 
-      VisitArgumentList(expr->arguments());
+      VisitExpressions(expr->arguments());
       CHECK_BAILOUT;
 
       HContext* context = new HContext;
       AddInstruction(context);
-      call = new HCallKeyed(context, key, argument_count);
+      call = PreProcessCall(new HCallKeyed(context, key, argument_count));
       call->set_position(expr->position());
-      PreProcessCall(call);
       Drop(1);  // Key.
       ast_context()->ReturnInstruction(call, expr->id());
       return;
     }
 
     // Named function call.
     expr->RecordTypeFeedback(oracle());
 
     if (TryCallApply(expr)) return;
     CHECK_BAILOUT;
 
-    VisitArgument(prop->obj());
-    CHECK_BAILOUT;
-    VisitArgumentList(expr->arguments());
+    VISIT_FOR_VALUE(prop->obj());
+    VisitExpressions(expr->arguments());
     CHECK_BAILOUT;
 
     Handle<String> name = prop->key()->AsLiteral()->AsPropertyName();
 
     expr->RecordTypeFeedback(oracle());
     ZoneMapList* types = expr->GetReceiverTypes();
 
     HValue* receiver =
         environment()->ExpressionStackAt(expr->arguments()->length());
     if (expr->IsMonomorphic()) {
       Handle<Map> receiver_map =
           (types == NULL) ? Handle<Map>::null() : types->first();
       if (TryInlineBuiltinFunction(expr,
                                    receiver,
                                    receiver_map,
                                    expr->check_type())) {
         return;
       }
 
       if (HasCustomCallGenerator(expr->target()) ||
+          CallOptimization(*expr->target()).is_simple_api_call() ||
           expr->check_type() != RECEIVER_MAP_CHECK) {
         // When the target has a custom call IC generator, use the IC,
-        // because it is likely to generate better code. Also use the
-        // IC when a primitive receiver check is required.
+        // because it is likely to generate better code.  Similarly, we
+        // generate better call stubs for some API functions.
+        // Also use the IC when a primitive receiver check is required.
         HContext* context = new HContext;
         AddInstruction(context);
-        call = new HCallNamed(context, name, argument_count);
+        call = PreProcessCall(new HCallNamed(context, name, argument_count));
       } else {
         AddCheckConstantFunction(expr, receiver, receiver_map, true);
 
         if (TryInline(expr)) {
-          if (subgraph()->HasExit()) {
-            HValue* return_value = Pop();
-            // If we inlined a function in a test context then we need to emit
-            // a simulate here to shadow the ones at the end of the
-            // predecessor blocks.  Those environments contain the return
-            // value on top and do not correspond to any actual state of the
-            // unoptimized code.
-            if (ast_context()->IsEffect()) AddSimulate(expr->id());
-            ast_context()->ReturnValue(return_value);
-          }
           return;
         } else {
           // Check for bailout, as the TryInline call in the if condition above
           // might return false due to bailout during hydrogen processing.
           CHECK_BAILOUT;
-          call = new HCallConstantFunction(expr->target(), argument_count);
+          call = PreProcessCall(new HCallConstantFunction(expr->target(),
+                                                          argument_count));
         }
       }
     } else if (types != NULL && types->length() > 1) {
       ASSERT(expr->check_type() == RECEIVER_MAP_CHECK);
       HandlePolymorphicCallNamed(expr, receiver, types, name);
       return;
 
     } else {
       HContext* context = new HContext;
       AddInstruction(context);
-      call = new HCallNamed(context, name, argument_count);
+      call = PreProcessCall(new HCallNamed(context, name, argument_count));
     }
 
   } else {
     Variable* var = expr->expression()->AsVariableProxy()->AsVariable();
     bool global_call = (var != NULL) && var->is_global() && !var->is_this();
 
     if (!global_call) {
       ++argument_count;
-      VisitArgument(expr->expression());
-      CHECK_BAILOUT;
+      VISIT_FOR_VALUE(expr->expression());
     }
 
     if (global_call) {
+      bool known_global_function = false;
       // If there is a global property cell for the name at compile time and
       // access check is not enabled we assume that the function will not change
       // and generate optimized code for calling the function.
-      CompilationInfo* info = graph()->info();
-      bool known_global_function = info->has_global_object() &&
-          !info->global_object()->IsAccessCheckNeeded() &&
-          expr->ComputeGlobalTarget(Handle<GlobalObject>(info->global_object()),
-                                    var->name());
+      if (info()->has_global_object() &&
+          !info()->global_object()->IsAccessCheckNeeded()) {
+        Handle<GlobalObject> global(info()->global_object());
+        known_global_function = expr->ComputeGlobalTarget(global, var->name());
+      }
       if (known_global_function) {
         // Push the global object instead of the global receiver because
         // code generated by the full code generator expects it.
         HContext* context = new HContext;
         HGlobalObject* global_object = new HGlobalObject(context);
         AddInstruction(context);
         PushAndAdd(global_object);
-        VisitArgumentList(expr->arguments());
+        VisitExpressions(expr->arguments());
         CHECK_BAILOUT;
 
         VISIT_FOR_VALUE(expr->expression());
         HValue* function = Pop();
         AddInstruction(new HCheckFunction(function, expr->target()));
 
         // Replace the global object with the global receiver.
         HGlobalReceiver* global_receiver = new HGlobalReceiver(global_object);
         // Index of the receiver from the top of the expression stack.
         const int receiver_index = argument_count - 1;
         AddInstruction(global_receiver);
         ASSERT(environment()->ExpressionStackAt(receiver_index)->
                IsGlobalObject());
         environment()->SetExpressionStackAt(receiver_index, global_receiver);
 
         if (TryInline(expr)) {
-          if (subgraph()->HasExit()) {
-            HValue* return_value = Pop();
-            // If we inlined a function in a test context then we need to
-            // emit a simulate here to shadow the ones at the end of the
-            // predecessor blocks.  Those environments contain the return
-            // value on top and do not correspond to any actual state of the
-            // unoptimized code.
-            if (ast_context()->IsEffect()) AddSimulate(expr->id());
-            ast_context()->ReturnValue(return_value);
-          }
           return;
         }
         // Check for bailout, as trying to inline might fail due to bailout
         // during hydrogen processing.
         CHECK_BAILOUT;
 
-        call = new HCallKnownGlobal(expr->target(), argument_count);
+        call = PreProcessCall(new HCallKnownGlobal(expr->target(),
+                                                   argument_count));
       } else {
         HContext* context = new HContext;
         AddInstruction(context);
         PushAndAdd(new HGlobalObject(context));
-        VisitArgumentList(expr->arguments());
+        VisitExpressions(expr->arguments());
         CHECK_BAILOUT;
 
-        call = new HCallGlobal(context, var->name(), argument_count);
+        call = PreProcessCall(new HCallGlobal(context,
+                                              var->name(),
+                                              argument_count));
       }
 
     } else {
       HContext* context = new HContext;
       HGlobalObject* global_object = new HGlobalObject(context);
       AddInstruction(context);
       AddInstruction(global_object);
       PushAndAdd(new HGlobalReceiver(global_object));
-      VisitArgumentList(expr->arguments());
+      VisitExpressions(expr->arguments());
       CHECK_BAILOUT;
 
-      call = new HCallFunction(context, argument_count);
+      call = PreProcessCall(new HCallFunction(context, argument_count));
     }
   }
 
   call->set_position(expr->position());
-  PreProcessCall(call);
   ast_context()->ReturnInstruction(call, expr->id());
 }
 
 
 void HGraphBuilder::VisitCallNew(CallNew* expr) {
   // The constructor function is also used as the receiver argument to the
   // JS construct call builtin.
-  VisitArgument(expr->expression());
-  CHECK_BAILOUT;
-  VisitArgumentList(expr->arguments());
+  VISIT_FOR_VALUE(expr->expression());
+  VisitExpressions(expr->arguments());
   CHECK_BAILOUT;
 
   HContext* context = new HContext;
   AddInstruction(context);
 
   // The constructor is both an operand to the instruction and an argument
   // to the construct call.
   int arg_count = expr->arguments()->length() + 1;  // Plus constructor.
   HValue* constructor = environment()->ExpressionStackAt(arg_count - 1);
-  HCall* call = new HCallNew(context, constructor, arg_count);
+  HCallNew* call = new HCallNew(context, constructor, arg_count);
   call->set_position(expr->position());
   PreProcessCall(call);
   ast_context()->ReturnInstruction(call, expr->id());
 }
 
 
 // Support for generating inlined runtime functions.
 
 // Lookup table for generators for runtime calls that are  generated inline.
 // Elements of the table are member pointers to functions of HGraphBuilder.
 #define INLINE_FUNCTION_GENERATOR_ADDRESS(Name, argc, ressize)  \
     &HGraphBuilder::Generate##Name,
 
 const HGraphBuilder::InlineFunctionGenerator
     HGraphBuilder::kInlineFunctionGenerators[] = {
         INLINE_FUNCTION_LIST(INLINE_FUNCTION_GENERATOR_ADDRESS)
         INLINE_RUNTIME_FUNCTION_LIST(INLINE_FUNCTION_GENERATOR_ADDRESS)
 };
 #undef INLINE_FUNCTION_GENERATOR_ADDRESS
 
 
 void HGraphBuilder::VisitCallRuntime(CallRuntime* expr) {
-  Handle<String> name = expr->name();
-  if (name->IsEqualTo(CStrVector("_Log"))) {
-    ast_context()->ReturnValue(graph()->GetConstantUndefined());
-    return;
+  if (expr->is_jsruntime()) {
+    BAILOUT("call to a JavaScript runtime function");
   }
 
   Runtime::Function* function = expr->function();
-  if (expr->is_jsruntime()) {
-    BAILOUT("call to a JavaScript runtime function");
-  }
   ASSERT(function != NULL);
-
-  VisitArgumentList(expr->arguments());
-  CHECK_BAILOUT;
-
-  int argument_count = expr->arguments()->length();
   if (function->intrinsic_type == Runtime::INLINE) {
-    ASSERT(name->length() > 0);
-    ASSERT(name->Get(0) == '_');
+    ASSERT(expr->name()->length() > 0);
+    ASSERT(expr->name()->Get(0) == '_');
     // Call to an inline function.
     int lookup_index = static_cast<int>(function->function_id) -
         static_cast<int>(Runtime::kFirstInlineFunction);
     ASSERT(lookup_index >= 0);
     ASSERT(static_cast<size_t>(lookup_index) <
            ARRAY_SIZE(kInlineFunctionGenerators));
     InlineFunctionGenerator generator = kInlineFunctionGenerators[lookup_index];
 
     // Call the inline code generator using the pointer-to-member.
-    (this->*generator)(argument_count, expr->id());
+    (this->*generator)(expr);
   } else {
     ASSERT(function->intrinsic_type == Runtime::RUNTIME);
-    HCall* call = new HCallRuntime(name, expr->function(), argument_count);
+    VisitArgumentList(expr->arguments());
+    CHECK_BAILOUT;
+
+    Handle<String> name = expr->name();
+    int argument_count = expr->arguments()->length();
+    HCallRuntime* call = new HCallRuntime(name, function, argument_count);
     call->set_position(RelocInfo::kNoPosition);
-    PreProcessCall(call);
+    Drop(argument_count);
     ast_context()->ReturnInstruction(call, expr->id());
   }
 }
 
 
 void HGraphBuilder::VisitUnaryOperation(UnaryOperation* expr) {
   Token::Value op = expr->op();
   if (op == Token::VOID) {
     VISIT_FOR_EFFECT(expr->expression());
     ast_context()->ReturnValue(graph()->GetConstantUndefined());
@@ skipping 29 matching lines @@
       BAILOUT("delete with global variable");
     } else {
       BAILOUT("delete with non-global variable");
     }
   } else if (op == Token::NOT) {
     if (ast_context()->IsTest()) {
       TestContext* context = TestContext::cast(ast_context());
       VisitForControl(expr->expression(),
                       context->if_false(),
                       context->if_true());
+    } else if (ast_context()->IsValue()) {
+      HBasicBlock* materialize_false = graph()->CreateBasicBlock();
+      HBasicBlock* materialize_true = graph()->CreateBasicBlock();
+      VISIT_FOR_CONTROL(expr->expression(),
+                        materialize_false,
+                        materialize_true);
+      materialize_false->SetJoinId(expr->expression()->id());
+      materialize_true->SetJoinId(expr->expression()->id());
+
+      set_current_block(materialize_false);
+      Push(graph()->GetConstantFalse());
+      set_current_block(materialize_true);
+      Push(graph()->GetConstantTrue());
+
+      HBasicBlock* join =
+          CreateJoin(materialize_false, materialize_true, expr->id());
+      set_current_block(join);
+      ast_context()->ReturnValue(Pop());
     } else {
-      HSubgraph* true_graph = CreateEmptySubgraph();
-      HSubgraph* false_graph = CreateEmptySubgraph();
-      VISIT_FOR_CONTROL(expr->expression(),
-                        false_graph->entry_block(),
-                        true_graph->entry_block());
-      true_graph->entry_block()->SetJoinId(expr->expression()->id());
-      true_graph->environment()->Push(graph_->GetConstantTrue());
+      ASSERT(ast_context()->IsEffect());
+      VisitForEffect(expr->expression());
+    }
 
-      false_graph->entry_block()->SetJoinId(expr->expression()->id());
-      false_graph->environment()->Push(graph_->GetConstantFalse());
-
-      current_subgraph_->AppendJoin(true_graph, false_graph, expr);
-      ast_context()->ReturnValue(Pop());
-    }
   } else if (op == Token::BIT_NOT || op == Token::SUB) {
     VISIT_FOR_VALUE(expr->expression());
     HValue* value = Pop();
     HInstruction* instr = NULL;
     switch (op) {
       case Token::BIT_NOT:
         instr = new HBitNot(value);
         break;
       case Token::SUB:
         instr = new HMul(graph_->GetConstantMinus1(), value);
@@ skipping 268 matching lines @@
       HBasicBlock* eval_right = graph()->CreateBasicBlock();
       if (is_logical_and) {
         VISIT_FOR_CONTROL(expr->left(), eval_right, context->if_false());
       } else {
         VISIT_FOR_CONTROL(expr->left(), context->if_true(), eval_right);
       }
       eval_right->SetJoinId(expr->RightId());
 
       // Translate right subexpression by visiting it in the same AST
       // context as the entire expression.
-      subgraph()->set_exit_block(eval_right);
+      set_current_block(eval_right);
       Visit(expr->right());
 
+    } else if (ast_context()->IsValue()) {
+      VISIT_FOR_VALUE(expr->left());
+      ASSERT(current_block() != NULL);
+
+      // We need an extra block to maintain edge-split form.
+      HBasicBlock* empty_block = graph()->CreateBasicBlock();
+      HBasicBlock* eval_right = graph()->CreateBasicBlock();
+      HTest* test = is_logical_and
+          ? new HTest(Top(), eval_right, empty_block)
+          : new HTest(Top(), empty_block, eval_right);
+      current_block()->Finish(test);
+
+      set_current_block(eval_right);
+      Drop(1);  // Value of the left subexpression.
+      VISIT_FOR_VALUE(expr->right());
+
+      HBasicBlock* join_block =
+          CreateJoin(empty_block, current_block(), expr->id());
+      set_current_block(join_block);
+      ast_context()->ReturnValue(Pop());
+
     } else {
-      VISIT_FOR_VALUE(expr->left());
-      ASSERT(current_subgraph_->HasExit());
+      ASSERT(ast_context()->IsEffect());
+      // In an effect context, we don't need the value of the left
+      // subexpression, only its control flow and side effects.  We need an
+      // extra block to maintain edge-split form.
+      HBasicBlock* empty_block = graph()->CreateBasicBlock();
+      HBasicBlock* right_block = graph()->CreateBasicBlock();
+      HBasicBlock* join_block = graph()->CreateBasicBlock();
+      if (is_logical_and) {
+        VISIT_FOR_CONTROL(expr->left(), right_block, empty_block);
+      } else {
+        VISIT_FOR_CONTROL(expr->left(), empty_block, right_block);
+      }
+      // TODO(kmillikin): Find a way to fix this.  It's ugly that there are
+      // actually two empty blocks (one here and one inserted by
+      // TestContext::BuildBranch, and that they both have an HSimulate
+      // though the second one is not a merge node, and that we really have
+      // no good AST ID to put on that first HSimulate.
+      empty_block->SetJoinId(expr->id());
+      right_block->SetJoinId(expr->RightId());
+      set_current_block(right_block);
+      VISIT_FOR_EFFECT(expr->right());
 
-      HValue* left = Top();
-      HEnvironment* environment_copy = environment()->Copy();
-      environment_copy->Pop();
-      HSubgraph* right_subgraph;
-      right_subgraph = CreateBranchSubgraph(environment_copy);
-      ADD_TO_SUBGRAPH(right_subgraph, expr->right());
-      current_subgraph_->AppendOptional(right_subgraph, is_logical_and, left);
-      current_subgraph_->exit_block()->SetJoinId(expr->id());
-      ast_context()->ReturnValue(Pop());
+      empty_block->Goto(join_block);
+      current_block()->Goto(join_block);
+      join_block->SetJoinId(expr->id());
+      set_current_block(join_block);
+      // We did not materialize any value in the predecessor environments,
+      // so there is no need to handle it here.
     }
 
   } else {
     VISIT_FOR_VALUE(expr->left());
     VISIT_FOR_VALUE(expr->right());
 
     HValue* right = Pop();
     HValue* left = Pop();
     HInstruction* instr = BuildBinaryOperation(expr, left, right);
     instr->set_position(expr->position());
@@ skipping 57 matching lines @@
     return;
   }
 
   VISIT_FOR_VALUE(expr->left());
   VISIT_FOR_VALUE(expr->right());
 
   HValue* right = Pop();
   HValue* left = Pop();
   Token::Value op = expr->op();
 
-  TypeInfo info = oracle()->CompareType(expr);
+  TypeInfo type_info = oracle()->CompareType(expr);
   HInstruction* instr = NULL;
   if (op == Token::INSTANCEOF) {
     // Check to see if the rhs of the instanceof is a global function not
     // residing in new space. If it is we assume that the function will stay the
     // same.
     Handle<JSFunction> target = Handle<JSFunction>::null();
     Variable* var = expr->right()->AsVariableProxy()->AsVariable();
     bool global_function = (var != NULL) && var->is_global() && !var->is_this();
-    CompilationInfo* info = graph()->info();
     if (global_function &&
-        info->has_global_object() &&
-        !info->global_object()->IsAccessCheckNeeded()) {
+        info()->has_global_object() &&
+        !info()->global_object()->IsAccessCheckNeeded()) {
       Handle<String> name = var->name();
-      Handle<GlobalObject> global(info->global_object());
+      Handle<GlobalObject> global(info()->global_object());
       LookupResult lookup;
       global->Lookup(*name, &lookup);
       if (lookup.IsProperty() &&
           lookup.type() == NORMAL &&
           lookup.GetValue()->IsJSFunction()) {
         Handle<JSFunction> candidate(JSFunction::cast(lookup.GetValue()));
         // If the function is in new space we assume it's more likely to
         // change and thus prefer the general IC code.
         if (!Heap::InNewSpace(*candidate)) {
           target = candidate;
         }
       }
     }
 
     // If the target is not null we have found a known global function that is
     // assumed to stay the same for this instanceof.
     if (target.is_null()) {
       HContext* context = new HContext;
       AddInstruction(context);
       instr = new HInstanceOf(context, left, right);
     } else {
       AddInstruction(new HCheckFunction(right, target));
       instr = new HInstanceOfKnownGlobal(left, target);
     }
   } else if (op == Token::IN) {
     BAILOUT("Unsupported comparison: in");
-  } else if (info.IsNonPrimitive()) {
+  } else if (type_info.IsNonPrimitive()) {
     switch (op) {
       case Token::EQ:
       case Token::EQ_STRICT: {
         AddInstruction(new HCheckNonSmi(left));
         AddInstruction(HCheckInstanceType::NewIsJSObjectOrJSFunction(left));
         AddInstruction(new HCheckNonSmi(right));
         AddInstruction(HCheckInstanceType::NewIsJSObjectOrJSFunction(right));
         instr = new HCompareJSObjectEq(left, right);
         break;
       }
       default:
         BAILOUT("Unsupported non-primitive compare");
         break;
     }
   } else {
     HCompare* compare = new HCompare(left, right, op);
-    Representation r = ToRepresentation(info);
+    Representation r = ToRepresentation(type_info);
     compare->SetInputRepresentation(r);
     instr = compare;
   }
   instr->set_position(expr->position());
   ast_context()->ReturnInstruction(instr, expr->id());
 }
 
 
 void HGraphBuilder::VisitCompareToNull(CompareToNull* expr) {
   VISIT_FOR_VALUE(expr->expression());
@@ skipping 20 matching lines @@
       (slot != NULL && slot->type() == Slot::LOOKUP) ||
       decl->mode() == Variable::CONST ||
       decl->fun() != NULL) {
     BAILOUT("unsupported declaration");
   }
 }
 
 
 // Generators for inline runtime functions.
 // Support for types.
-void HGraphBuilder::GenerateIsSmi(int argument_count, int ast_id) {
-  ASSERT(argument_count == 1);
+void HGraphBuilder::GenerateIsSmi(CallRuntime* call) {
+  ASSERT(call->arguments()->length() == 1);
+  VISIT_FOR_VALUE(call->arguments()->at(0));
   HValue* value = Pop();
   HIsSmi* result = new HIsSmi(value);
-  ast_context()->ReturnInstruction(result, ast_id);
-}
-
-
-void HGraphBuilder::GenerateIsSpecObject(int argument_count, int ast_id) {
-  ASSERT(argument_count == 1);
+  ast_context()->ReturnInstruction(result, call->id());
+}
+
+
+void HGraphBuilder::GenerateIsSpecObject(CallRuntime* call) {
+  ASSERT(call->arguments()->length() == 1);
+  VISIT_FOR_VALUE(call->arguments()->at(0));
   HValue* value = Pop();
   HHasInstanceType* result =
       new HHasInstanceType(value, FIRST_JS_OBJECT_TYPE, LAST_TYPE);
-  ast_context()->ReturnInstruction(result, ast_id);
-}
-
-
-void HGraphBuilder::GenerateIsFunction(int argument_count, int ast_id) {
-  ASSERT(argument_count == 1);
+  ast_context()->ReturnInstruction(result, call->id());
+}
+
+
+void HGraphBuilder::GenerateIsFunction(CallRuntime* call) {
+  ASSERT(call->arguments()->length() == 1);
+  VISIT_FOR_VALUE(call->arguments()->at(0));
   HValue* value = Pop();
   HHasInstanceType* result = new HHasInstanceType(value, JS_FUNCTION_TYPE);
-  ast_context()->ReturnInstruction(result, ast_id);
-}
-
-
-void HGraphBuilder::GenerateHasCachedArrayIndex(int argument_count,
-                                                int ast_id) {
-  ASSERT(argument_count == 1);
+  ast_context()->ReturnInstruction(result, call->id());
+}
+
+
+void HGraphBuilder::GenerateHasCachedArrayIndex(CallRuntime* call) {
+  ASSERT(call->arguments()->length() == 1);
+  VISIT_FOR_VALUE(call->arguments()->at(0));
   HValue* value = Pop();
   HHasCachedArrayIndex* result = new HHasCachedArrayIndex(value);
-  ast_context()->ReturnInstruction(result, ast_id);
-}
-
-
-void HGraphBuilder::GenerateIsArray(int argument_count, int ast_id) {
-  ASSERT(argument_count == 1);
+  ast_context()->ReturnInstruction(result, call->id());
+}
+
+
+void HGraphBuilder::GenerateIsArray(CallRuntime* call) {
+  ASSERT(call->arguments()->length() == 1);
+  VISIT_FOR_VALUE(call->arguments()->at(0));
   HValue* value = Pop();
   HHasInstanceType* result = new HHasInstanceType(value, JS_ARRAY_TYPE);
-  ast_context()->ReturnInstruction(result, ast_id);
-}
-
-
-void HGraphBuilder::GenerateIsRegExp(int argument_count, int ast_id) {
-  ASSERT(argument_count == 1);
+  ast_context()->ReturnInstruction(result, call->id());
+}
+
+
+void HGraphBuilder::GenerateIsRegExp(CallRuntime* call) {
+  ASSERT(call->arguments()->length() == 1);
+  VISIT_FOR_VALUE(call->arguments()->at(0));
   HValue* value = Pop();
   HHasInstanceType* result = new HHasInstanceType(value, JS_REGEXP_TYPE);
-  ast_context()->ReturnInstruction(result, ast_id);
-}
-
-
-void HGraphBuilder::GenerateIsObject(int argument_count, int ast_id) {
-  ASSERT(argument_count == 1);
-
+  ast_context()->ReturnInstruction(result, call->id());
+}
+
+
+void HGraphBuilder::GenerateIsObject(CallRuntime* call) {
+  ASSERT(call->arguments()->length() == 1);
+  VISIT_FOR_VALUE(call->arguments()->at(0));
   HValue* value = Pop();
   HIsObject* test = new HIsObject(value);
-  ast_context()->ReturnInstruction(test, ast_id);
-}
-
-
-void HGraphBuilder::GenerateIsNonNegativeSmi(int argument_count,
-                                             int ast_id) {
+  ast_context()->ReturnInstruction(test, call->id());
+}
+
+
+void HGraphBuilder::GenerateIsNonNegativeSmi(CallRuntime* call) {
   BAILOUT("inlined runtime function: IsNonNegativeSmi");
 }
 
 
-void HGraphBuilder::GenerateIsUndetectableObject(int argument_count,
-                                                 int ast_id) {
+void HGraphBuilder::GenerateIsUndetectableObject(CallRuntime* call) {
   BAILOUT("inlined runtime function: IsUndetectableObject");
 }
 
 
 void HGraphBuilder::GenerateIsStringWrapperSafeForDefaultValueOf(
-    int argument_count,
-    int ast_id) {
+    CallRuntime* call) {
   BAILOUT("inlined runtime function: IsStringWrapperSafeForDefaultValueOf");
 }
 
 
 // Support for construct call checks.
-void HGraphBuilder::GenerateIsConstructCall(int argument_count, int ast_id) {
-  ASSERT(argument_count == 0);
-  ast_context()->ReturnInstruction(new HIsConstructCall, ast_id);
+void HGraphBuilder::GenerateIsConstructCall(CallRuntime* call) {
+  ASSERT(call->arguments()->length() == 0);
+  ast_context()->ReturnInstruction(new HIsConstructCall, call->id());
 }
 
 
 // Support for arguments.length and arguments[?].
-void HGraphBuilder::GenerateArgumentsLength(int argument_count, int ast_id) {
-  ASSERT(argument_count == 0);
+void HGraphBuilder::GenerateArgumentsLength(CallRuntime* call) {
+  ASSERT(call->arguments()->length() == 0);
   HInstruction* elements = AddInstruction(new HArgumentsElements);
   HArgumentsLength* result = new HArgumentsLength(elements);
-  ast_context()->ReturnInstruction(result, ast_id);
-}
-
-
-void HGraphBuilder::GenerateArguments(int argument_count, int ast_id) {
-  ASSERT(argument_count == 1);
+  ast_context()->ReturnInstruction(result, call->id());
+}
+
+
+void HGraphBuilder::GenerateArguments(CallRuntime* call) {
+  ASSERT(call->arguments()->length() == 1);
+  VISIT_FOR_VALUE(call->arguments()->at(0));
   HValue* index = Pop();
   HInstruction* elements = AddInstruction(new HArgumentsElements);
   HInstruction* length = AddInstruction(new HArgumentsLength(elements));
   HAccessArgumentsAt* result = new HAccessArgumentsAt(elements, length, index);
-  ast_context()->ReturnInstruction(result, ast_id);
+  ast_context()->ReturnInstruction(result, call->id());
 }
 
 
 // Support for accessing the class and value fields of an object.
-void HGraphBuilder::GenerateClassOf(int argument_count, int ast_id) {
+void HGraphBuilder::GenerateClassOf(CallRuntime* call) {
   // The special form detected by IsClassOfTest is detected before we get here
   // and does not cause a bailout.
   BAILOUT("inlined runtime function: ClassOf");
 }
 
 
-void HGraphBuilder::GenerateValueOf(int argument_count, int ast_id) {
-  ASSERT(argument_count == 1);
+void HGraphBuilder::GenerateValueOf(CallRuntime* call) {
+  ASSERT(call->arguments()->length() == 1);
+  VISIT_FOR_VALUE(call->arguments()->at(0));
   HValue* value = Pop();
   HValueOf* result = new HValueOf(value);
-  ast_context()->ReturnInstruction(result, ast_id);
-}
-
-
-void HGraphBuilder::GenerateSetValueOf(int argument_count, int ast_id) {
+  ast_context()->ReturnInstruction(result, call->id());
+}
+
+
+void HGraphBuilder::GenerateSetValueOf(CallRuntime* call) {
   BAILOUT("inlined runtime function: SetValueOf");
 }
 
 
 // Fast support for charCodeAt(n).
-void HGraphBuilder::GenerateStringCharCodeAt(int argument_count, int ast_id) {
-  ASSERT(argument_count == 2);
+void HGraphBuilder::GenerateStringCharCodeAt(CallRuntime* call) {
+  ASSERT(call->arguments()->length() == 2);
+  VISIT_FOR_VALUE(call->arguments()->at(0));
+  VISIT_FOR_VALUE(call->arguments()->at(1));
   HValue* index = Pop();
   HValue* string = Pop();
   HStringCharCodeAt* result = BuildStringCharCodeAt(string, index);
-  ast_context()->ReturnInstruction(result, ast_id);
+  ast_context()->ReturnInstruction(result, call->id());
 }
 
 
 // Fast support for string.charAt(n) and string[n].
-void HGraphBuilder::GenerateStringCharFromCode(int argument_count,
-                                               int ast_id) {
-  BAILOUT("inlined runtime function: StringCharFromCode");
+void HGraphBuilder::GenerateStringCharFromCode(CallRuntime* call) {
+  ASSERT(call->arguments()->length() == 1);
+  VISIT_FOR_VALUE(call->arguments()->at(0));
+  HValue* char_code = Pop();
+  HStringCharFromCode* result = new HStringCharFromCode(char_code);
+  ast_context()->ReturnInstruction(result, call->id());
 }
 
 
 // Fast support for string.charAt(n) and string[n].
-void HGraphBuilder::GenerateStringCharAt(int argument_count, int ast_id) {
-  ASSERT_EQ(2, argument_count);
-  HContext* context = new HContext;
-  AddInstruction(context);
-  HCallStub* result =
-      new HCallStub(context, CodeStub::StringCharAt, argument_count);
-  PreProcessCall(result);
-  ast_context()->ReturnInstruction(result, ast_id);
+void HGraphBuilder::GenerateStringCharAt(CallRuntime* call) {
+  ASSERT(call->arguments()->length() == 2);
+  VISIT_FOR_VALUE(call->arguments()->at(0));
+  VISIT_FOR_VALUE(call->arguments()->at(1));
+  HValue* index = Pop();
+  HValue* string = Pop();
+  HStringCharCodeAt* char_code = BuildStringCharCodeAt(string, index);
+  AddInstruction(char_code);
+  HStringCharFromCode* result = new HStringCharFromCode(char_code);
+  ast_context()->ReturnInstruction(result, call->id());
 }
 
 
 // Fast support for object equality testing.
-void HGraphBuilder::GenerateObjectEquals(int argument_count, int ast_id) {
-  ASSERT(argument_count == 2);
+void HGraphBuilder::GenerateObjectEquals(CallRuntime* call) {
+  ASSERT(call->arguments()->length() == 2);
+  VISIT_FOR_VALUE(call->arguments()->at(0));
+  VISIT_FOR_VALUE(call->arguments()->at(1));
   HValue* right = Pop();
   HValue* left = Pop();
   HCompareJSObjectEq* result = new HCompareJSObjectEq(left, right);
-  ast_context()->ReturnInstruction(result, ast_id);
-}
-
-
-void HGraphBuilder::GenerateLog(int argument_count, int ast_id) {
-  UNREACHABLE();  // We caught this in VisitCallRuntime.
+  ast_context()->ReturnInstruction(result, call->id());
+}
+
+
+void HGraphBuilder::GenerateLog(CallRuntime* call) {
+  // %_Log is ignored in optimized code.
+  ast_context()->ReturnValue(graph()->GetConstantUndefined());
 }
 
 
 // Fast support for Math.random().
-void HGraphBuilder::GenerateRandomHeapNumber(int argument_count, int ast_id) {
+void HGraphBuilder::GenerateRandomHeapNumber(CallRuntime* call) {
   BAILOUT("inlined runtime function: RandomHeapNumber");
 }
 
 
 // Fast support for StringAdd.
-void HGraphBuilder::GenerateStringAdd(int argument_count, int ast_id) {
-  ASSERT_EQ(2, argument_count);
+void HGraphBuilder::GenerateStringAdd(CallRuntime* call) {
+  ASSERT_EQ(2, call->arguments()->length());
+  VisitArgumentList(call->arguments());
+  CHECK_BAILOUT;
+  HContext* context = new HContext;
+  AddInstruction(context);
+  HCallStub* result = new HCallStub(context, CodeStub::StringAdd, 2);
+  Drop(2);
+  ast_context()->ReturnInstruction(result, call->id());
+}
+
+
+// Fast support for SubString.
+void HGraphBuilder::GenerateSubString(CallRuntime* call) {
+  ASSERT_EQ(3, call->arguments()->length());
+  VisitArgumentList(call->arguments());
+  CHECK_BAILOUT;
+  HContext* context = new HContext;
+  AddInstruction(context);
+  HCallStub* result = new HCallStub(context, CodeStub::SubString, 3);
+  Drop(3);
+  ast_context()->ReturnInstruction(result, call->id());
+}
+
+
+// Fast support for StringCompare.
+void HGraphBuilder::GenerateStringCompare(CallRuntime* call) {
+  ASSERT_EQ(2, call->arguments()->length());
+  VisitArgumentList(call->arguments());
+  CHECK_BAILOUT;
+  HContext* context = new HContext;
+  AddInstruction(context);
+  HCallStub* result = new HCallStub(context, CodeStub::StringCompare, 2);
+  Drop(2);
+  ast_context()->ReturnInstruction(result, call->id());
+}
+
+
+// Support for direct calls from JavaScript to native RegExp code.
+void HGraphBuilder::GenerateRegExpExec(CallRuntime* call) {
+  ASSERT_EQ(4, call->arguments()->length());
+  VisitArgumentList(call->arguments());
+  CHECK_BAILOUT;
+  HContext* context = new HContext;
+  AddInstruction(context);
+  HCallStub* result = new HCallStub(context, CodeStub::RegExpExec, 4);
+  Drop(4);
+  ast_context()->ReturnInstruction(result, call->id());
+}
+
+
+// Construct a RegExp exec result with two in-object properties.
+void HGraphBuilder::GenerateRegExpConstructResult(CallRuntime* call) {
+  ASSERT_EQ(3, call->arguments()->length());
+  VisitArgumentList(call->arguments());
+  CHECK_BAILOUT;
   HContext* context = new HContext;
   AddInstruction(context);
   HCallStub* result =
-      new HCallStub(context, CodeStub::StringAdd, argument_count);
-  PreProcessCall(result);
-  ast_context()->ReturnInstruction(result, ast_id);
-}
-
-
-// Fast support for SubString.
-void HGraphBuilder::GenerateSubString(int argument_count, int ast_id) {
-  ASSERT_EQ(3, argument_count);
-  HContext* context = new HContext;
-  AddInstruction(context);
-  HCallStub* result =
-      new HCallStub(context, CodeStub::SubString, argument_count);
-  PreProcessCall(result);
-  ast_context()->ReturnInstruction(result, ast_id);
-}
-
-
-// Fast support for StringCompare.
-void HGraphBuilder::GenerateStringCompare(int argument_count, int ast_id) {
-  ASSERT_EQ(2, argument_count);
-  HContext* context = new HContext;
-  AddInstruction(context);
-  HCallStub* result =
-      new HCallStub(context, CodeStub::StringCompare, argument_count);
-  PreProcessCall(result);
-  ast_context()->ReturnInstruction(result, ast_id);
-}
-
-
-// Support for direct calls from JavaScript to native RegExp code.
-void HGraphBuilder::GenerateRegExpExec(int argument_count, int ast_id) {
-  ASSERT_EQ(4, argument_count);
-  HContext* context = new HContext;
-  AddInstruction(context);
-  HCallStub* result =
-      new HCallStub(context, CodeStub::RegExpExec, argument_count);
-  PreProcessCall(result);
-  ast_context()->ReturnInstruction(result, ast_id);
-}
-
-
-// Construct a RegExp exec result with two in-object properties.
-void HGraphBuilder::GenerateRegExpConstructResult(int argument_count,
-                                                  int ast_id) {
-  ASSERT_EQ(3, argument_count);
-  HContext* context = new HContext;
-  AddInstruction(context);
-  HCallStub* result =
-      new HCallStub(context, CodeStub::RegExpConstructResult, argument_count);
-  PreProcessCall(result);
-  ast_context()->ReturnInstruction(result, ast_id);
+      new HCallStub(context, CodeStub::RegExpConstructResult, 3);
+  Drop(3);
+  ast_context()->ReturnInstruction(result, call->id());
 }
 
 
 // Support for fast native caches.
-void HGraphBuilder::GenerateGetFromCache(int argument_count, int ast_id) {
+void HGraphBuilder::GenerateGetFromCache(CallRuntime* call) {
   BAILOUT("inlined runtime function: GetFromCache");
 }
 
 
 // Fast support for number to string.
-void HGraphBuilder::GenerateNumberToString(int argument_count, int ast_id) {
-  ASSERT_EQ(1, argument_count);
-  HContext* context = new HContext;
-  AddInstruction(context);
-  HCallStub* result =
-      new HCallStub(context, CodeStub::NumberToString, argument_count);
-  PreProcessCall(result);
-  ast_context()->ReturnInstruction(result, ast_id);
+void HGraphBuilder::GenerateNumberToString(CallRuntime* call) {
+  ASSERT_EQ(1, call->arguments()->length());
+  VisitArgumentList(call->arguments());
+  CHECK_BAILOUT;
+  HContext* context = new HContext;
+  AddInstruction(context);
+  HCallStub* result = new HCallStub(context, CodeStub::NumberToString, 1);
+  Drop(1);
+  ast_context()->ReturnInstruction(result, call->id());
 }
 
 
 // Fast swapping of elements. Takes three expressions, the object and two
 // indices. This should only be used if the indices are known to be
 // non-negative and within bounds of the elements array at the call site.
-void HGraphBuilder::GenerateSwapElements(int argument_count, int ast_id) {
+void HGraphBuilder::GenerateSwapElements(CallRuntime* call) {
   BAILOUT("inlined runtime function: SwapElements");
 }
 
 
 // Fast call for custom callbacks.
-void HGraphBuilder::GenerateCallFunction(int argument_count, int ast_id) {
+void HGraphBuilder::GenerateCallFunction(CallRuntime* call) {
   BAILOUT("inlined runtime function: CallFunction");
 }
 
 
 // Fast call to math functions.
-void HGraphBuilder::GenerateMathPow(int argument_count, int ast_id) {
-  ASSERT_EQ(2, argument_count);
+void HGraphBuilder::GenerateMathPow(CallRuntime* call) {
+  ASSERT_EQ(2, call->arguments()->length());
+  VISIT_FOR_VALUE(call->arguments()->at(0));
+  VISIT_FOR_VALUE(call->arguments()->at(1));
   HValue* right = Pop();
   HValue* left = Pop();
   HPower* result = new HPower(left, right);
-  ast_context()->ReturnInstruction(result, ast_id);
-}
-
-
-void HGraphBuilder::GenerateMathSin(int argument_count, int ast_id) {
-  ASSERT_EQ(1, argument_count);
-  HContext* context = new HContext;
-  AddInstruction(context);
-  HCallStub* result =
-      new HCallStub(context, CodeStub::TranscendentalCache, argument_count);
+  ast_context()->ReturnInstruction(result, call->id());
+}
+
+
+void HGraphBuilder::GenerateMathSin(CallRuntime* call) {
+  ASSERT_EQ(1, call->arguments()->length());
+  VisitArgumentList(call->arguments());
+  CHECK_BAILOUT;
+  HContext* context = new HContext;
+  AddInstruction(context);
+  HCallStub* result = new HCallStub(context, CodeStub::TranscendentalCache, 1);
   result->set_transcendental_type(TranscendentalCache::SIN);
-  PreProcessCall(result);
-  ast_context()->ReturnInstruction(result, ast_id);
-}
-
-
-void HGraphBuilder::GenerateMathCos(int argument_count, int ast_id) {
-  ASSERT_EQ(1, argument_count);
-  HContext* context = new HContext;
-  AddInstruction(context);
-  HCallStub* result =
-      new HCallStub(context, CodeStub::TranscendentalCache, argument_count);
+  Drop(1);
+  ast_context()->ReturnInstruction(result, call->id());
+}
+
+
+void HGraphBuilder::GenerateMathCos(CallRuntime* call) {
+  ASSERT_EQ(1, call->arguments()->length());
+  VisitArgumentList(call->arguments());
+  CHECK_BAILOUT;
+  HContext* context = new HContext;
+  AddInstruction(context);
+  HCallStub* result = new HCallStub(context, CodeStub::TranscendentalCache, 1);
   result->set_transcendental_type(TranscendentalCache::COS);
-  PreProcessCall(result);
-  ast_context()->ReturnInstruction(result, ast_id);
-}
-
-
-void HGraphBuilder::GenerateMathLog(int argument_count, int ast_id) {
-  ASSERT_EQ(1, argument_count);
-  HContext* context = new HContext;
-  AddInstruction(context);
-  HCallStub* result =
-      new HCallStub(context, CodeStub::TranscendentalCache, argument_count);
+  Drop(1);
+  ast_context()->ReturnInstruction(result, call->id());
+}
+
+
+void HGraphBuilder::GenerateMathLog(CallRuntime* call) {
+  ASSERT_EQ(1, call->arguments()->length());
+  VisitArgumentList(call->arguments());
+  CHECK_BAILOUT;
+  HContext* context = new HContext;
+  AddInstruction(context);
+  HCallStub* result = new HCallStub(context, CodeStub::TranscendentalCache, 1);
   result->set_transcendental_type(TranscendentalCache::LOG);
-  PreProcessCall(result);
-  ast_context()->ReturnInstruction(result, ast_id);
-}
-
-
-void HGraphBuilder::GenerateMathSqrt(int argument_count, int ast_id) {
+  Drop(1);
+  ast_context()->ReturnInstruction(result, call->id());
+}
+
+
+void HGraphBuilder::GenerateMathSqrt(CallRuntime* call) {
   BAILOUT("inlined runtime function: MathSqrt");
 }
 
 
 // Check whether two RegExps are equivalent
-void HGraphBuilder::GenerateIsRegExpEquivalent(int argument_count,
-                                               int ast_id) {
+void HGraphBuilder::GenerateIsRegExpEquivalent(CallRuntime* call) {
   BAILOUT("inlined runtime function: IsRegExpEquivalent");
 }
 
 
-void HGraphBuilder::GenerateGetCachedArrayIndex(int argument_count,
-                                                int ast_id) {
-  BAILOUT("inlined runtime function: GetCachedArrayIndex");
-}
-
-
-void HGraphBuilder::GenerateFastAsciiArrayJoin(int argument_count,
-                                               int ast_id) {
+void HGraphBuilder::GenerateGetCachedArrayIndex(CallRuntime* call) {
+  ASSERT(call->arguments()->length() == 1);
+  VISIT_FOR_VALUE(call->arguments()->at(0));
+  HValue* value = Pop();
+  HGetCachedArrayIndex* result = new HGetCachedArrayIndex(value);
+  ast_context()->ReturnInstruction(result, call->id());
+}
+
+
+void HGraphBuilder::GenerateFastAsciiArrayJoin(CallRuntime* call) {
   BAILOUT("inlined runtime function: FastAsciiArrayJoin");
 }
 
 
 #undef BAILOUT
 #undef CHECK_BAILOUT
 #undef VISIT_FOR_EFFECT
 #undef VISIT_FOR_VALUE
 #undef ADD_TO_SUBGRAPH
 
@@ skipping 330 matching lines @@
       }
     }
   }
 }
 
 
 void HTracer::TraceLiveRanges(const char* name, LAllocator* allocator) {
   Tag tag(this, "intervals");
   PrintStringProperty("name", name);
 
-  const ZoneList<LiveRange*>* fixed_d = allocator->fixed_double_live_ranges();
+  const Vector<LiveRange*>* fixed_d = allocator->fixed_double_live_ranges();
   for (int i = 0; i < fixed_d->length(); ++i) {
     TraceLiveRange(fixed_d->at(i), "fixed");
   }
 
-  const ZoneList<LiveRange*>* fixed = allocator->fixed_live_ranges();
+  const Vector<LiveRange*>* fixed = allocator->fixed_live_ranges();
   for (int i = 0; i < fixed->length(); ++i) {
     TraceLiveRange(fixed->at(i), "fixed");
   }
 
   const ZoneList<LiveRange*>* live_ranges = allocator->live_ranges();
   for (int i = 0; i < live_ranges->length(); ++i) {
     TraceLiveRange(live_ranges->at(i), "object");
   }
 }
 
@@ skipping 24 matching lines @@
     if (range->IsChild()) {
       parent_index = range->parent()->id();
     } else {
       parent_index = range->id();
     }
     LOperand* op = range->FirstHint();
     int hint_index = -1;
     if (op != NULL && op->IsUnallocated()) hint_index = op->VirtualRegister();
     trace_.Add(" %d %d", parent_index, hint_index);
     UseInterval* cur_interval = range->first_interval();
-    while (cur_interval != NULL) {
+    while (cur_interval != NULL && range->Covers(cur_interval->start())) {
       trace_.Add(" [%d, %d[",
                  cur_interval->start().Value(),
                  cur_interval->end().Value());
       cur_interval = cur_interval->next();
     }
 
     UsePosition* current_pos = range->first_pos();
     while (current_pos != NULL) {
-      if (current_pos->RegisterIsBeneficial()) {
+      if (current_pos->RegisterIsBeneficial() || FLAG_trace_all_uses) {
         trace_.Add(" %d M", current_pos->pos().Value());
       }
       current_pos = current_pos->next();
     }
 
     trace_.Add(" \"\"\n");
   }
 }
 
 
 void HTracer::FlushToFile() {
   AppendChars(filename_, *trace_.ToCString(), trace_.length(), false);
   trace_.Reset();
 }
 
 
+void HStatistics::Initialize(CompilationInfo* info) {
+  source_size_ += info->shared_info()->SourceSize();
+}
+
+
 void HStatistics::Print() {
   PrintF("Timing results:\n");
   int64_t sum = 0;
   for (int i = 0; i < timing_.length(); ++i) {
     sum += timing_[i];
   }
 
   for (int i = 0; i < names_.length(); ++i) {
     PrintF("%30s", names_[i]);
     double ms = static_cast<double>(timing_[i]) / 1000;
     double percent = static_cast<double>(timing_[i]) * 100 / sum;
     PrintF(" - %7.3f ms / %4.1f %% ", ms, percent);
 
     unsigned size = sizes_[i];
     double size_percent = static_cast<double>(size) * 100 / total_size_;
     PrintF(" %8u bytes / %4.1f %%\n", size, size_percent);
   }
-  PrintF("%30s - %7.3f ms           %8u bytes\n", "Sum",
-         static_cast<double>(sum) / 1000,
-         total_size_);
+  double source_size_in_kb = static_cast<double>(source_size_) / 1024;
+  PrintF("%30s - %7.3f ms           %7.3f bytes\n", "Sum",
+         (static_cast<double>(sum) / 1000) / source_size_in_kb,
+         total_size_ / source_size_in_kb);
   PrintF("---------------------------------------------------------------\n");
   PrintF("%30s - %7.3f ms (%.1f times slower than full code gen)\n",
          "Total",
          static_cast<double>(total_) / 1000,
          static_cast<double>(total_) / full_code_gen_);
 }
 
 
 void HStatistics::SaveTiming(const char* name, int64_t ticks, unsigned size) {
   if (name == HPhase::kFullCodeGen) {
@@ skipping 24 matching lines @@
                    HGraph* graph,
                    LChunk* chunk,
                    LAllocator* allocator) {
   name_ = name;
   graph_ = graph;
   chunk_ = chunk;
   allocator_ = allocator;
   if (allocator != NULL && chunk_ == NULL) {
     chunk_ = allocator->chunk();
   }
-  if (FLAG_time_hydrogen) start_ = OS::Ticks();
+  if (FLAG_hydrogen_stats) start_ = OS::Ticks();
   start_allocation_size_ = Zone::allocation_size_;
 }
 
 
 void HPhase::End() const {
-  if (FLAG_time_hydrogen) {
+  if (FLAG_hydrogen_stats) {
     int64_t end = OS::Ticks();
     unsigned size = Zone::allocation_size_ - start_allocation_size_;
     HStatistics::Instance()->SaveTiming(name_, end - start_, size);
   }
 
   if (FLAG_trace_hydrogen) {
     if (graph_ != NULL) HTracer::Instance()->TraceHydrogen(name_, graph_);
     if (chunk_ != NULL) HTracer::Instance()->TraceLithium(name_, chunk_);
     if (allocator_ != NULL) {
       HTracer::Instance()->TraceLiveRanges(name_, allocator_);
     }
   }
 
 #ifdef DEBUG
   if (graph_ != NULL) graph_->Verify();
   if (allocator_ != NULL) allocator_->Verify();
 #endif
 }
 
 } }  // namespace v8::internal