[Isolates] Merge from bleeding_edge to isolates, revisions 6100-6300.

src/hydrogen.cc

-// Copyright 2010 the V8 project authors. All rights reserved.
+// 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
 //       with the distribution.
@@ skipping 109 matching lines @@
 
 HSimulate* HBasicBlock::CreateSimulate(int id) {
   ASSERT(HasEnvironment());
   HEnvironment* environment = last_environment();
   ASSERT(id == AstNode::kNoNumber ||
          environment->closure()->shared()->VerifyBailoutId(id));
 
   int push_count = environment->push_count();
   int pop_count = environment->pop_count();
 
-  int length = environment->values()->length();
+  int length = environment->length();
   HSimulate* instr = new HSimulate(id, pop_count, length);
   for (int i = push_count - 1; i >= 0; --i) {
     instr->AddPushedValue(environment->ExpressionStackAt(i));
   }
   for (int i = 0; i < environment->assigned_variables()->length(); ++i) {
     int index = environment->assigned_variables()->at(i);
     instr->AddAssignedValue(index, environment->Lookup(index));
   }
   environment->ClearHistory();
   return instr;
@@ skipping 73 matching lines @@
 
 
 void HBasicBlock::RegisterPredecessor(HBasicBlock* pred) {
   if (!predecessors_.is_empty()) {
     // Only loop header blocks can have a predecessor added after
     // instructions have been added to the block (they have phis for all
     // values in the environment, these phis may be eliminated later).
     ASSERT(IsLoopHeader() || first_ == NULL);
     HEnvironment* incoming_env = pred->last_environment();
     if (IsLoopHeader()) {
-      ASSERT(phis()->length() == incoming_env->values()->length());
+      ASSERT(phis()->length() == incoming_env->length());
       for (int i = 0; i < phis_.length(); ++i) {
         phis_[i]->AddInput(incoming_env->values()->at(i));
       }
     } else {
       last_environment()->AddIncomingEdge(this, pred->last_environment());
     }
   } else if (!HasEnvironment() && !IsFinished()) {
     ASSERT(!IsLoopHeader());
     SetInitialEnvironment(pred->last_environment()->Copy());
   }
@@ skipping 1739 matching lines @@
   }
 }
 
 
 // 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_count_ = owner->environment()->total_count();
+  original_length_ = owner->environment()->length();
 #endif
 }
 
 
 AstContext::~AstContext() {
   owner_->set_ast_context(outer_);  // Pop.
 }
 
 
 EffectContext::~EffectContext() {
   ASSERT(owner()->HasStackOverflow() ||
          !owner()->subgraph()->HasExit() ||
-         owner()->environment()->total_count() == original_count_);
+         owner()->environment()->length() == original_length_);
 }
 
 
 ValueContext::~ValueContext() {
   ASSERT(owner()->HasStackOverflow() ||
          !owner()->subgraph()->HasExit() ||
-         owner()->environment()->total_count() == original_count_ + 1);
+         owner()->environment()->length() == original_length_ + 1);
 }
 
 
 void EffectContext::ReturnValue(HValue* value) {
   // The value is simply ignored.
 }
 
 
 void ValueContext::ReturnValue(HValue* value) {
   // The value is tracked in the bailout environment, and communicated
@@ skipping 320 matching lines @@
 
   // 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()->values()->length(); ++i) {
+  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) {
     HArgumentsObject* object = new HArgumentsObject;
     AddInstruction(object);
     graph()->SetArgumentsObject(object);
     environment()->Bind(scope->arguments(), object);
@@ skipping 338 matching lines @@
   HValue* true_value = graph()->GetConstantTrue();
   HBranch* branch = new HBranch(non_osr_entry, osr_entry, true_value);
   exit_block()->Finish(branch);
 
   HBasicBlock* loop_predecessor = graph()->CreateBasicBlock();
   non_osr_entry->Goto(loop_predecessor);
 
   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()->total_count();
+  int count = osr_entry->last_environment()->length();
   ASSERT(count == (osr_entry->last_environment()->parameter_count() +
                    osr_entry->last_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));
@@ skipping 380 matching lines @@
   current_subgraph_->exit_block()->Finish(
       new HCompareMapAndBranch(receiver,
                                Handle<Map>(maps->first()),
                                subgraphs->first()->entry_block(),
                                else_subgraph->entry_block()));
 
   // Join all the call subgraphs in a new basic block and make
   // this basic block the current basic block.
   HBasicBlock* join_block = graph_->CreateBasicBlock();
   for (int i = 0; i < subgraphs->length(); ++i) {
-    if (subgraphs->at(i)->HasExit()) {
-      subgraphs->at(i)->exit_block()->Goto(join_block);
+    HSubgraph* subgraph = subgraphs->at(i);
+    if (subgraph->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.
+      HBasicBlock* subgraph_exit = subgraph->exit_block();
+      if (ast_context()->IsEffect()) {
+        subgraph_exit->last_environment()->Drop(1);
+      }
+      subgraph_exit->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.
@@ skipping 117 matching lines @@
     }
   }
 
   // If none of the properties were named fields we generate a
   // generic store.
   if (maps.length() == 0) {
     HInstruction* instr = new HStoreNamedGeneric(object, name, value);
     Push(value);
     instr->set_position(expr->position());
     AddInstruction(instr);
-    if (instr->HasSideEffects()) AddSimulate(expr->id());
+    if (instr->HasSideEffects()) AddSimulate(expr->AssignmentId());
+    ast_context()->ReturnValue(Pop());
   } else {
     // Build subgraph for generic store through IC.
     {
       HSubgraph* subgraph = CreateBranchSubgraph(environment());
       SubgraphScope scope(this, subgraph);
       if (!needs_generic && FLAG_deoptimize_uncommon_cases) {
         subgraph->FinishExit(new HDeoptimize());
       } else {
         HInstruction* instr = new HStoreNamedGeneric(object, name, value);
         Push(value);
         instr->set_position(expr->position());
         AddInstruction(instr);
       }
       subgraphs.Add(subgraph);
     }
 
     HBasicBlock* new_exit_block =
-        BuildTypeSwitch(&maps, &subgraphs, object, expr->AssignmentId());
+        BuildTypeSwitch(&maps, &subgraphs, object, 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 (subgraph()->HasExit()) 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 263 matching lines @@
     } else {
       needs_generic = true;
     }
   }
 
   // If none of the properties were named fields we generate a
   // generic load.
   if (maps.length() == 0) {
     HInstruction* instr = BuildLoadNamedGeneric(object, expr);
     instr->set_position(expr->position());
-    PushAndAdd(instr);
-    if (instr->HasSideEffects()) AddSimulate(expr->id());
+    ast_context()->ReturnInstruction(instr, expr->id());
   } else {
     // Build subgraph for generic load through IC.
     {
       HSubgraph* subgraph = CreateBranchSubgraph(environment());
       SubgraphScope scope(this, subgraph);
       if (!needs_generic && FLAG_deoptimize_uncommon_cases) {
         subgraph->FinishExit(new HDeoptimize());
       } else {
         HInstruction* instr = BuildLoadNamedGeneric(object, expr);
         instr->set_position(expr->position());
         PushAndAdd(instr);
       }
       subgraphs.Add(subgraph);
     }
 
     HBasicBlock* new_exit_block =
         BuildTypeSwitch(&maps, &subgraphs, object, 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 (subgraph()->HasExit()) 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 52 matching lines @@
 
 
 HInstruction* HGraphBuilder::BuildLoadKeyedFastElement(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());
   AddInstruction(new HCheckMap(object, map));
-  HInstruction* elements = AddInstruction(new HLoadElements(object));
-  HInstruction* length = AddInstruction(new HArrayLength(elements));
-  AddInstruction(new HBoundsCheck(key, length));
+  bool is_array = (map->instance_type() == JS_ARRAY_TYPE);
+  HLoadElements* elements = new HLoadElements(object);
+  HInstruction* length = NULL;
+  if (is_array) {
+    length = AddInstruction(new HJSArrayLength(object));
+    AddInstruction(new HBoundsCheck(key, length));
+    AddInstruction(elements);
+  } else {
+    AddInstruction(elements);
+    length = AddInstruction(new HFixedArrayLength(elements));
+    AddInstruction(new HBoundsCheck(key, length));
+  }
   return new HLoadKeyedFastElement(elements, key);
 }
 
 
 HInstruction* HGraphBuilder::BuildStoreKeyedGeneric(HValue* object,
                                                     HValue* key,
                                                     HValue* value) {
   return new HStoreKeyedGeneric(object, key, value);
 }
 
 
 HInstruction* HGraphBuilder::BuildStoreKeyedFastElement(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());
   AddInstruction(new HCheckMap(object, map));
   HInstruction* elements = AddInstruction(new HLoadElements(object));
   AddInstruction(new HCheckMap(elements, FACTORY->fixed_array_map()));
   bool is_array = (map->instance_type() == JS_ARRAY_TYPE);
   HInstruction* length = NULL;
   if (is_array) {
-    length = AddInstruction(new HArrayLength(object));
+    length = AddInstruction(new HJSArrayLength(object));
   } else {
-    length = AddInstruction(new HArrayLength(elements));
+    length = AddInstruction(new HFixedArrayLength(elements));
   }
   AddInstruction(new HBoundsCheck(key, length));
   return new HStoreKeyedFastElement(elements, key, val);
 }
 
 
 bool HGraphBuilder::TryArgumentsAccess(Property* expr) {
   VariableProxy* proxy = expr->obj()->AsVariableProxy();
   if (proxy == NULL) return false;
   if (!proxy->var()->IsStackAllocated()) return false;
@@ skipping 26 matching lines @@
 
   if (TryArgumentsAccess(expr)) return;
   CHECK_BAILOUT;
 
   VISIT_FOR_VALUE(expr->obj());
 
   HInstruction* instr = NULL;
   if (expr->IsArrayLength()) {
     HValue* array = Pop();
     AddInstruction(new HCheckNonSmi(array));
-    instr = new HArrayLength(array);
+    AddInstruction(new HCheckInstanceType(array, JS_ARRAY_TYPE, JS_ARRAY_TYPE));
+    instr = new HJSArrayLength(array);
+
+  } 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();
 
     HValue* obj = Pop();
     if (expr->IsMonomorphic()) {
       instr = BuildLoadNamed(obj, expr, types->first(), name);
     } else if (types != NULL && types->length() > 1) {
       HandlePolymorphicLoadNamedField(expr, obj, types, name);
@@ skipping 26 matching lines @@
                                              Handle<Map> receiver_map,
                                              bool smi_and_map_check) {
   // Constant functions have the nice property that the map will change if they
   // are overwritten.  Therefore it is enough to check the map of the holder and
   // its prototypes.
   if (smi_and_map_check) {
     AddInstruction(new HCheckNonSmi(receiver));
     AddInstruction(new HCheckMap(receiver, receiver_map));
   }
   if (!expr->holder().is_null()) {
-    AddInstruction(new HCheckPrototypeMaps(receiver,
-                                           expr->holder(),
-                                           receiver_map));
+    AddInstruction(new HCheckPrototypeMaps(
+        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);
@@ skipping 51 matching lines @@
         call->set_position(expr->position());
         ProcessCall(call);
         PushAndAdd(call);
       }
       subgraphs.Add(subgraph);
     }
 
     HBasicBlock* new_exit_block =
         BuildTypeSwitch(&maps, &subgraphs, receiver, expr->id());
     subgraph()->set_exit_block(new_exit_block);
-    if (new_exit_block != NULL) ast_context()->ReturnValue(Pop());
+    // 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());
+    }
   }
 }
 
 
 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);
@@ skipping 115 matching lines @@
     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()));
+  TypeFeedbackOracle new_oracle(
+      Handle<Code>(shared->code()),
+      Handle<Context>(target->context()->global_context()));
   oracle_ = &new_oracle;
   graph()->info()->SetOsrAstId(AstNode::kNoNumber);
 
   HSubgraph* body = CreateInlinedSubgraph(env, target, function);
   body->exit_block()->AddInstruction(new HEnterInlined(target, function));
   AddToSubgraph(body, function->body());
   if (HasStackOverflow()) {
     // Bail out if the inline function did, as we cannot residualize a call
     // instead.
     delete test_context;
@@ skipping 181 matching lines @@
   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());
   if (!arg_two_value->CheckFlag(HValue::kIsArguments)) return false;
 
-  if (!expr->IsMonomorphic()) return false;
+  if (!expr->IsMonomorphic() ||
+      expr->check_type() != RECEIVER_MAP_CHECK) return false;
 
   // Found pattern f.apply(receiver, arguments).
   VisitForValue(prop->obj());
   if (HasStackOverflow()) return false;
   HValue* function = Pop();
   VisitForValue(args->at(0));
   if (HasStackOverflow()) return false;
   HValue* receiver = Pop();
   HInstruction* elements = AddInstruction(new HArgumentsElements);
   HInstruction* length = AddInstruction(new HArgumentsLength(elements));
@@ skipping 48 matching lines @@
     HValue* receiver = VisitArgument(prop->obj());
     CHECK_BAILOUT;
     VisitArgumentList(expr->arguments());
     CHECK_BAILOUT;
 
     Handle<String> name = prop->key()->AsLiteral()->AsPropertyName();
 
     expr->RecordTypeFeedback(oracle());
     ZoneMapList* types = expr->GetReceiverTypes();
 
-    if (expr->IsMonomorphic()) {
+    if (expr->IsMonomorphic() && expr->check_type() == RECEIVER_MAP_CHECK) {
       AddCheckConstantFunction(expr, receiver, types->first(), true);
 
       if (TryMathFunctionInline(expr)) {
         return;
       } else 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);
       }
 
     } else if (types != NULL && types->length() > 1) {
+      ASSERT(expr->check_type() == RECEIVER_MAP_CHECK);
       HandlePolymorphicCallNamed(expr, receiver, types, name);
       return;
 
     } else {
       call = new HCallNamed(name, argument_count);
     }
 
   } else {
     Variable* var = expr->expression()->AsVariableProxy()->AsVariable();
     bool global_call = (var != NULL) && var->is_global() && !var->is_this();
@@ skipping 554 matching lines @@
   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, TypeFeedbackOracle::RESULT);
   HInstruction* instr = NULL;
   if (op == Token::INSTANCEOF) {
-    instr = new HInstanceOf(left, right);
+    // 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()) {
+      Handle<String> name = var->name();
+      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 (!info->isolate()->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()) {
+      instr = new HInstanceOf(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()) {
     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);
@@ skipping 387 matching lines @@
   parameter_count_ = parameter_count;
   local_count_ = local_count;
 
   // Avoid reallocating the temporaries' backing store on the first Push.
   int total = parameter_count + local_count + stack_height;
   values_.Initialize(total + 4);
   for (int i = 0; i < total; ++i) values_.Add(NULL);
 }
 
 
+void HEnvironment::Initialize(const HEnvironment* other) {
+  closure_ = other->closure();
+  values_.AddAll(other->values_);
+  assigned_variables_.AddAll(other->assigned_variables_);
+  parameter_count_ = other->parameter_count_;
+  local_count_ = other->local_count_;
+  if (other->outer_ != NULL) outer_ = other->outer_->Copy();  // Deep copy.
+  pop_count_ = other->pop_count_;
+  push_count_ = other->push_count_;
+  ast_id_ = other->ast_id_;
+}
+
+
 void HEnvironment::AddIncomingEdge(HBasicBlock* block, HEnvironment* other) {
   ASSERT(!block->IsLoopHeader());
   ASSERT(values_.length() == other->values_.length());
 
   int length = values_.length();
   for (int i = 0; i < length; ++i) {
     HValue* value = values_[i];
     if (value != NULL && value->IsPhi() && value->block() == block) {
       // There is already a phi for the i'th value.
       HPhi* phi = HPhi::cast(value);
@@ skipping 10 matching lines @@
         phi->AddInput(old_value);
       }
       phi->AddInput(other->values_[i]);
       this->values_[i] = phi;
       block->AddPhi(phi);
     }
   }
 }
 
 
-void HEnvironment::Initialize(const HEnvironment* other) {
-  closure_ = other->closure();
-  values_.AddAll(other->values_);
-  assigned_variables_.AddAll(other->assigned_variables_);
-  parameter_count_ = other->parameter_count_;
-  local_count_ = other->local_count_;
-  if (other->outer_ != NULL) outer_ = other->outer_->Copy();  // Deep copy.
-  pop_count_ = other->pop_count_;
-  push_count_ = other->push_count_;
-  ast_id_ = other->ast_id_;
+void HEnvironment::Bind(int index, HValue* value) {
+  ASSERT(value != NULL);
+  if (!assigned_variables_.Contains(index)) {
+    assigned_variables_.Add(index);
+  }
+  values_[index] = value;
 }
 
 
-int HEnvironment::IndexFor(Variable* variable) const {
-  Slot* slot = variable->AsSlot();
-  ASSERT(slot != NULL && slot->IsStackAllocated());
-  if (slot->type() == Slot::PARAMETER) {
-    return slot->index() + 1;
-  } else {
-    return parameter_count_ + slot->index();
+bool HEnvironment::HasExpressionAt(int index) const {
+  return index >= parameter_count_ + local_count_;
+}
+
+
+bool HEnvironment::ExpressionStackIsEmpty() const {
+  int first_expression = parameter_count() + local_count();
+  ASSERT(length() >= first_expression);
+  return length() == first_expression;
+}
+
+
+void HEnvironment::SetExpressionStackAt(int index_from_top, HValue* value) {
+  int count = index_from_top + 1;
+  int index = values_.length() - count;
+  ASSERT(HasExpressionAt(index));
+  // The push count must include at least the element in question or else
+  // the new value will not be included in this environment's history.
+  if (push_count_ < count) {
+    // This is the same effect as popping then re-pushing 'count' elements.
+    pop_count_ += (count - push_count_);
+    push_count_ = count;
+  }
+  values_[index] = value;
+}
+
+
+void HEnvironment::Drop(int count) {
+  for (int i = 0; i < count; ++i) {
+    Pop();
   }
 }
 
 
 HEnvironment* HEnvironment::Copy() const {
   return new HEnvironment(this);
 }
 
 
 HEnvironment* HEnvironment::CopyWithoutHistory() const {
@@ skipping 44 matching lines @@
   for (int i = 0; i < local_count; ++i) {
     inner->SetValueAt(local_base + i, undefined);
   }
 
   inner->set_ast_id(function->id());
   return inner;
 }
 
 
 void HEnvironment::PrintTo(StringStream* stream) {
-  for (int i = 0; i < total_count(); i++) {
+  for (int i = 0; i < length(); i++) {
     if (i == 0) stream->Add("parameters\n");
     if (i == parameter_count()) stream->Add("locals\n");
     if (i == parameter_count() + local_count()) stream->Add("expressions");
     HValue* val = values_.at(i);
     stream->Add("%d: ", i);
     if (val != NULL) {
       val->PrintNameTo(stream);
     } else {
       stream->Add("NULL");
     }
@@ skipping 217 matching lines @@
   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(" - %0.3f ms / %0.3f %% \n", ms, percent);
+    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 - %0.3f ms \n", "Sum", static_cast<double>(sum) / 1000);
+  PrintF("%30s - %7.3f ms           %8u bytes\n", "Sum",
+         static_cast<double>(sum) / 1000,
+         total_size_);
   PrintF("---------------------------------------------------------------\n");
-  PrintF("%30s - %0.3f ms (%0.1f times slower than full code gen)\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) {
+void HStatistics::SaveTiming(const char* name, int64_t ticks, unsigned size) {
   if (name == HPhase::kFullCodeGen) {
     full_code_gen_ += ticks;
   } else if (name == HPhase::kTotal) {
     total_ += ticks;
   } else {
+    total_size_ += size;
     for (int i = 0; i < names_.length(); ++i) {
       if (names_[i] == name) {
         timing_[i] += ticks;
+        sizes_[i] += size;
         return;
       }
     }
     names_.Add(name);
     timing_.Add(ticks);
+    sizes_.Add(size);
   }
 }
 
 
 const char* const HPhase::kFullCodeGen = "Full code generator";
 const char* const HPhase::kTotal = "Total";
 
 
 void HPhase::Begin(const char* name,
                    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();
+  start_allocation_size_ = Zone::allocation_size_;
 }
 
 
 void HPhase::End() const {
   if (FLAG_time_hydrogen) {
     int64_t end = OS::Ticks();
-    HStatistics::Instance()->SaveTiming(name_, end - start_);
+    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 (chunk_ != NULL) chunk_->Verify();
   if (allocator_ != NULL) allocator_->Verify();
 #endif
 }
 
 } }  // namespace v8::internal