diff --git a/src/full-codegen/x64/full-codegen-x64.cc b/src/full-codegen/x64/full-codegen-x64.cc
index 992e7fe..1ef9cee 100644
--- a/src/full-codegen/x64/full-codegen-x64.cc
+++ b/src/full-codegen/x64/full-codegen-x64.cc
@@ -166,7 +166,8 @@
       __ Push(rdi);
       __ Push(info->scope()->GetScopeInfo(info->isolate()));
       __ CallRuntime(Runtime::kNewScriptContext);
-      PrepareForBailoutForId(BailoutId::ScriptContext(), TOS_REG);
+      PrepareForBailoutForId(BailoutId::ScriptContext(),
+                             BailoutState::TOS_REGISTER);
       // The new target value is not used, clobbering is safe.
       DCHECK_NULL(info->scope()->new_target_var());
     } else {
@@ -222,7 +223,8 @@
   // Register holding this function and new target are both trashed in case we
   // bailout here. But since that can happen only when new target is not used
   // and we allocate a context, the value of |function_in_register| is correct.
-  PrepareForBailoutForId(BailoutId::FunctionContext(), NO_REGISTERS);
+  PrepareForBailoutForId(BailoutId::FunctionContext(),
+                         BailoutState::NO_REGISTERS);
 
   // Possibly set up a local binding to the this function which is used in
   // derived constructors with super calls.
@@ -286,7 +288,8 @@
 
   // Visit the declarations and body unless there is an illegal
   // redeclaration.
-  PrepareForBailoutForId(BailoutId::FunctionEntry(), NO_REGISTERS);
+  PrepareForBailoutForId(BailoutId::FunctionEntry(),
+                         BailoutState::NO_REGISTERS);
   {
     Comment cmnt(masm_, "[ Declarations");
     VisitDeclarations(scope()->declarations());
@@ -299,7 +302,8 @@
 
   {
     Comment cmnt(masm_, "[ Stack check");
-    PrepareForBailoutForId(BailoutId::Declarations(), NO_REGISTERS);
+    PrepareForBailoutForId(BailoutId::Declarations(),
+                           BailoutState::NO_REGISTERS);
     Label ok;
     __ CompareRoot(rsp, Heap::kStackLimitRootIndex);
     __ j(above_equal, &ok, Label::kNear);
@@ -372,11 +376,11 @@
   }
   __ bind(&ok);
 
-  PrepareForBailoutForId(stmt->EntryId(), NO_REGISTERS);
+  PrepareForBailoutForId(stmt->EntryId(), BailoutState::NO_REGISTERS);
   // Record a mapping of the OSR id to this PC.  This is used if the OSR
   // entry becomes the target of a bailout.  We don't expect it to be, but
   // we want it to work if it is.
-  PrepareForBailoutForId(stmt->OsrEntryId(), NO_REGISTERS);
+  PrepareForBailoutForId(stmt->OsrEntryId(), BailoutState::NO_REGISTERS);
 }
 
 void FullCodeGenerator::EmitProfilingCounterHandlingForReturnSequence(
@@ -425,6 +429,9 @@
   }
 }
 
+void FullCodeGenerator::RestoreContext() {
+  __ movp(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
+}
 
 void FullCodeGenerator::StackValueContext::Plug(Variable* var) const {
   DCHECK(var->IsStackAllocated() || var->IsContextSlot());
@@ -689,7 +696,7 @@
 
   Label skip;
   if (should_normalize) __ jmp(&skip, Label::kNear);
-  PrepareForBailout(expr, TOS_REG);
+  PrepareForBailout(expr, BailoutState::TOS_REGISTER);
   if (should_normalize) {
     __ CompareRoot(rax, Heap::kTrueValueRootIndex);
     Split(equal, if_true, if_false, NULL);
@@ -720,15 +727,13 @@
   VariableProxy* proxy = declaration->proxy();
   VariableMode mode = declaration->mode();
   Variable* variable = proxy->var();
-  bool hole_init = mode == LET || mode == CONST || mode == CONST_LEGACY;
+  bool hole_init = mode == LET || mode == CONST;
   switch (variable->location()) {
     case VariableLocation::GLOBAL:
     case VariableLocation::UNALLOCATED:
+      DCHECK(!variable->binding_needs_init());
       globals_->Add(variable->name(), zone());
-      globals_->Add(variable->binding_needs_init()
-                        ? isolate()->factory()->the_hole_value()
-                    : isolate()->factory()->undefined_value(),
-                    zone());
+      globals_->Add(isolate()->factory()->undefined_value(), zone());
       break;
 
     case VariableLocation::PARAMETER:
@@ -747,7 +752,7 @@
         __ LoadRoot(kScratchRegister, Heap::kTheHoleValueRootIndex);
         __ movp(ContextOperand(rsi, variable->index()), kScratchRegister);
         // No write barrier since the hole value is in old space.
-        PrepareForBailoutForId(proxy->id(), NO_REGISTERS);
+        PrepareForBailoutForId(proxy->id(), BailoutState::NO_REGISTERS);
       }
       break;
 
@@ -767,6 +772,7 @@
       }
       __ Push(Smi::FromInt(variable->DeclarationPropertyAttributes()));
       __ CallRuntime(Runtime::kDeclareLookupSlot);
+      PrepareForBailoutForId(proxy->id(), BailoutState::NO_REGISTERS);
       break;
     }
   }
@@ -811,7 +817,7 @@
                                 kDontSaveFPRegs,
                                 EMIT_REMEMBERED_SET,
                                 OMIT_SMI_CHECK);
-      PrepareForBailoutForId(proxy->id(), NO_REGISTERS);
+      PrepareForBailoutForId(proxy->id(), BailoutState::NO_REGISTERS);
       break;
     }
 
@@ -821,6 +827,7 @@
       VisitForStackValue(declaration->fun());
       PushOperand(Smi::FromInt(variable->DeclarationPropertyAttributes()));
       CallRuntimeWithOperands(Runtime::kDeclareLookupSlot);
+      PrepareForBailoutForId(proxy->id(), BailoutState::NO_REGISTERS);
       break;
     }
   }
@@ -851,7 +858,7 @@
 
   // Keep the switch value on the stack until a case matches.
   VisitForStackValue(stmt->tag());
-  PrepareForBailoutForId(stmt->EntryId(), NO_REGISTERS);
+  PrepareForBailoutForId(stmt->EntryId(), BailoutState::NO_REGISTERS);
 
   ZoneList<CaseClause*>* clauses = stmt->cases();
   CaseClause* default_clause = NULL;  // Can occur anywhere in the list.
@@ -901,7 +908,7 @@
 
     Label skip;
     __ jmp(&skip, Label::kNear);
-    PrepareForBailout(clause, TOS_REG);
+    PrepareForBailout(clause, BailoutState::TOS_REGISTER);
     __ CompareRoot(rax, Heap::kTrueValueRootIndex);
     __ j(not_equal, &next_test);
     __ Drop(1);
@@ -929,12 +936,12 @@
     Comment cmnt(masm_, "[ Case body");
     CaseClause* clause = clauses->at(i);
     __ bind(clause->body_target());
-    PrepareForBailoutForId(clause->EntryId(), NO_REGISTERS);
+    PrepareForBailoutForId(clause->EntryId(), BailoutState::NO_REGISTERS);
     VisitStatements(clause->statements());
   }
 
   __ bind(nested_statement.break_label());
-  PrepareForBailoutForId(stmt->ExitId(), NO_REGISTERS);
+  PrepareForBailoutForId(stmt->ExitId(), BailoutState::NO_REGISTERS);
 }
 
 
@@ -967,15 +974,13 @@
   ToObjectStub stub(isolate());
   __ CallStub(&stub);
   __ bind(&done_convert);
-  PrepareForBailoutForId(stmt->ToObjectId(), TOS_REG);
+  PrepareForBailoutForId(stmt->ToObjectId(), BailoutState::TOS_REGISTER);
   __ Push(rax);
 
-  // Check cache validity in generated code. This is a fast case for
-  // the JSObject::IsSimpleEnum cache validity checks. If we cannot
-  // guarantee cache validity, call the runtime system to check cache
-  // validity or get the property names in a fixed array.
-  // Note: Proxies never have an enum cache, so will always take the
-  // slow path.
+  // Check cache validity in generated code. If we cannot guarantee cache
+  // validity, call the runtime system to check cache validity or get the
+  // property names in a fixed array. Note: Proxies never have an enum cache,
+  // so will always take the slow path.
   Label call_runtime;
   __ CheckEnumCache(&call_runtime);
 
@@ -989,7 +994,7 @@
   __ bind(&call_runtime);
   __ Push(rax);  // Duplicate the enumerable object on the stack.
   __ CallRuntime(Runtime::kForInEnumerate);
-  PrepareForBailoutForId(stmt->EnumId(), TOS_REG);
+  PrepareForBailoutForId(stmt->EnumId(), BailoutState::TOS_REGISTER);
 
   // If we got a map from the runtime call, we can do a fast
   // modification check. Otherwise, we got a fixed array, and we have
@@ -1031,7 +1036,7 @@
   __ Push(rax);  // Array
   __ movp(rax, FieldOperand(rax, FixedArray::kLengthOffset));
   __ Push(rax);  // Fixed array length (as smi).
-  PrepareForBailoutForId(stmt->PrepareId(), NO_REGISTERS);
+  PrepareForBailoutForId(stmt->PrepareId(), BailoutState::NO_REGISTERS);
   __ Push(Smi::FromInt(0));  // Initial index.
 
   // Generate code for doing the condition check.
@@ -1073,7 +1078,7 @@
   __ Push(rcx);  // Enumerable.
   __ Push(rbx);  // Current entry.
   __ CallRuntime(Runtime::kForInFilter);
-  PrepareForBailoutForId(stmt->FilterId(), TOS_REG);
+  PrepareForBailoutForId(stmt->FilterId(), BailoutState::TOS_REGISTER);
   __ CompareRoot(rax, Heap::kUndefinedValueRootIndex);
   __ j(equal, loop_statement.continue_label());
   __ movp(rbx, rax);
@@ -1085,11 +1090,11 @@
   // Perform the assignment as if via '='.
   { EffectContext context(this);
     EmitAssignment(stmt->each(), stmt->EachFeedbackSlot());
-    PrepareForBailoutForId(stmt->AssignmentId(), NO_REGISTERS);
+    PrepareForBailoutForId(stmt->AssignmentId(), BailoutState::NO_REGISTERS);
   }
 
   // Both Crankshaft and Turbofan expect BodyId to be right before stmt->body().
-  PrepareForBailoutForId(stmt->BodyId(), NO_REGISTERS);
+  PrepareForBailoutForId(stmt->BodyId(), BailoutState::NO_REGISTERS);
   // Generate code for the body of the loop.
   Visit(stmt->body());
 
@@ -1106,7 +1111,7 @@
   DropOperands(5);
 
   // Exit and decrement the loop depth.
-  PrepareForBailoutForId(stmt->ExitId(), NO_REGISTERS);
+  PrepareForBailoutForId(stmt->ExitId(), BailoutState::NO_REGISTERS);
   __ bind(&exit);
   decrement_loop_depth();
 }
@@ -1237,16 +1242,11 @@
   } else if (var->mode() == DYNAMIC_LOCAL) {
     Variable* local = var->local_if_not_shadowed();
     __ movp(rax, ContextSlotOperandCheckExtensions(local, slow));
-    if (local->mode() == LET || local->mode() == CONST ||
-        local->mode() == CONST_LEGACY) {
+    if (local->mode() == LET || local->mode() == CONST) {
       __ CompareRoot(rax, Heap::kTheHoleValueRootIndex);
       __ j(not_equal, done);
-      if (local->mode() == CONST_LEGACY) {
-        __ LoadRoot(rax, Heap::kUndefinedValueRootIndex);
-      } else {  // LET || CONST
-        __ Push(var->name());
-        __ CallRuntime(Runtime::kThrowReferenceError);
-      }
+      __ Push(var->name());
+      __ CallRuntime(Runtime::kThrowReferenceError);
     }
     __ jmp(done);
   }
@@ -1270,7 +1270,7 @@
                                          TypeofMode typeof_mode) {
   // Record position before possible IC call.
   SetExpressionPosition(proxy);
-  PrepareForBailoutForId(proxy->BeforeId(), NO_REGISTERS);
+  PrepareForBailoutForId(proxy->BeforeId(), BailoutState::NO_REGISTERS);
   Variable* var = proxy->var();
 
   // Three cases: global variables, lookup variables, and all other types of
@@ -1301,10 +1301,6 @@
           // binding in harmony mode.
           __ Push(var->name());
           __ CallRuntime(Runtime::kThrowReferenceError);
-        } else {
-          // Uninitialized legacy const bindings are unholed.
-          DCHECK(var->mode() == CONST_LEGACY);
-          __ LoadRoot(rax, Heap::kUndefinedValueRootIndex);
         }
         __ bind(&done);
         context()->Plug(rax);
@@ -1382,8 +1378,9 @@
     __ Move(rdx, Smi::FromInt(flags));
     FastCloneShallowObjectStub stub(isolate(), expr->properties_count());
     __ CallStub(&stub);
+    RestoreContext();
   }
-  PrepareForBailoutForId(expr->CreateLiteralId(), TOS_REG);
+  PrepareForBailoutForId(expr->CreateLiteralId(), BailoutState::TOS_REGISTER);
 
   // If result_saved is true the result is on top of the stack.  If
   // result_saved is false the result is in rax.
@@ -1419,7 +1416,7 @@
             __ movp(StoreDescriptor::ReceiverRegister(), Operand(rsp, 0));
             EmitLoadStoreICSlot(property->GetSlot(0));
             CallStoreIC();
-            PrepareForBailoutForId(key->id(), NO_REGISTERS);
+            PrepareForBailoutForId(key->id(), BailoutState::NO_REGISTERS);
 
             if (NeedsHomeObject(value)) {
               EmitSetHomeObjectAccumulator(value, 0, property->GetSlot(1));
@@ -1448,7 +1445,7 @@
         DCHECK(property->emit_store());
         CallRuntimeWithOperands(Runtime::kInternalSetPrototype);
         PrepareForBailoutForId(expr->GetIdForPropertySet(property_index),
-                               NO_REGISTERS);
+                               BailoutState::NO_REGISTERS);
         break;
       case ObjectLiteral::Property::GETTER:
         if (property->emit_store()) {
@@ -1502,7 +1499,7 @@
       DCHECK(property->emit_store());
       CallRuntimeWithOperands(Runtime::kInternalSetPrototype);
       PrepareForBailoutForId(expr->GetIdForPropertySet(property_index),
-                             NO_REGISTERS);
+                             BailoutState::NO_REGISTERS);
     } else {
       EmitPropertyKey(property, expr->GetIdForPropertyName(property_index));
       VisitForStackValue(value);
@@ -1575,7 +1572,7 @@
     FastCloneShallowArrayStub stub(isolate(), allocation_site_mode);
     __ CallStub(&stub);
   }
-  PrepareForBailoutForId(expr->CreateLiteralId(), TOS_REG);
+  PrepareForBailoutForId(expr->CreateLiteralId(), BailoutState::TOS_REGISTER);
 
   bool result_saved = false;  // Is the result saved to the stack?
   ZoneList<Expression*>* subexprs = expr->values();
@@ -1605,7 +1602,8 @@
         CodeFactory::KeyedStoreIC(isolate(), language_mode()).code();
     CallIC(ic);
 
-    PrepareForBailoutForId(expr->GetIdForElement(array_index), NO_REGISTERS);
+    PrepareForBailoutForId(expr->GetIdForElement(array_index),
+                           BailoutState::NO_REGISTERS);
   }
 
   // In case the array literal contains spread expressions it has two parts. The
@@ -1625,7 +1623,8 @@
     VisitForStackValue(subexpr);
     CallRuntimeWithOperands(Runtime::kAppendElement);
 
-    PrepareForBailoutForId(expr->GetIdForElement(array_index), NO_REGISTERS);
+    PrepareForBailoutForId(expr->GetIdForElement(array_index),
+                           BailoutState::NO_REGISTERS);
   }
 
   if (result_saved) {
@@ -1640,7 +1639,6 @@
   DCHECK(expr->target()->IsValidReferenceExpressionOrThis());
 
   Comment cmnt(masm_, "[ Assignment");
-  SetExpressionPosition(expr, INSERT_BREAK);
 
   Property* property = expr->target()->AsProperty();
   LhsKind assign_type = Property::GetAssignType(property);
@@ -1704,23 +1702,27 @@
       switch (assign_type) {
         case VARIABLE:
           EmitVariableLoad(expr->target()->AsVariableProxy());
-          PrepareForBailout(expr->target(), TOS_REG);
+          PrepareForBailout(expr->target(), BailoutState::TOS_REGISTER);
           break;
         case NAMED_PROPERTY:
           EmitNamedPropertyLoad(property);
-          PrepareForBailoutForId(property->LoadId(), TOS_REG);
+          PrepareForBailoutForId(property->LoadId(),
+                                 BailoutState::TOS_REGISTER);
           break;
         case NAMED_SUPER_PROPERTY:
           EmitNamedSuperPropertyLoad(property);
-          PrepareForBailoutForId(property->LoadId(), TOS_REG);
+          PrepareForBailoutForId(property->LoadId(),
+                                 BailoutState::TOS_REGISTER);
           break;
         case KEYED_SUPER_PROPERTY:
           EmitKeyedSuperPropertyLoad(property);
-          PrepareForBailoutForId(property->LoadId(), TOS_REG);
+          PrepareForBailoutForId(property->LoadId(),
+                                 BailoutState::TOS_REGISTER);
           break;
         case KEYED_PROPERTY:
           EmitKeyedPropertyLoad(property);
-          PrepareForBailoutForId(property->LoadId(), TOS_REG);
+          PrepareForBailoutForId(property->LoadId(),
+                                 BailoutState::TOS_REGISTER);
           break;
       }
     }
@@ -1739,7 +1741,7 @@
       EmitBinaryOp(expr->binary_operation(), op);
     }
     // Deoptimization point in case the binary operation may have side effects.
-    PrepareForBailout(expr->binary_operation(), TOS_REG);
+    PrepareForBailout(expr->binary_operation(), BailoutState::TOS_REGISTER);
   } else {
     VisitForAccumulatorValue(expr->value());
   }
@@ -1751,7 +1753,7 @@
     case VARIABLE:
       EmitVariableAssignment(expr->target()->AsVariableProxy()->var(),
                              expr->op(), expr->AssignmentSlot());
-      PrepareForBailoutForId(expr->AssignmentId(), TOS_REG);
+      PrepareForBailoutForId(expr->AssignmentId(), BailoutState::TOS_REGISTER);
       context()->Plug(rax);
       break;
     case NAMED_PROPERTY:
@@ -1780,21 +1782,26 @@
   // this.  It stays on the stack while we update the iterator.
   VisitForStackValue(expr->expression());
 
-  Label suspend, continuation, post_runtime, resume;
+  Label suspend, continuation, post_runtime, resume, exception;
 
   __ jmp(&suspend);
   __ bind(&continuation);
-  // When we arrive here, the stack top is the resume mode and
-  // result_register() holds the input value (the argument given to the
-  // respective resume operation).
+  // When we arrive here, rax holds the generator object.
   __ RecordGeneratorContinuation();
-  __ Pop(rbx);
-  __ SmiCompare(rbx, Smi::FromInt(JSGeneratorObject::RETURN));
-  __ j(not_equal, &resume);
+  __ movp(rbx, FieldOperand(rax, JSGeneratorObject::kResumeModeOffset));
+  __ movp(rax, FieldOperand(rax, JSGeneratorObject::kInputOffset));
+  STATIC_ASSERT(JSGeneratorObject::kNext < JSGeneratorObject::kReturn);
+  STATIC_ASSERT(JSGeneratorObject::kThrow > JSGeneratorObject::kReturn);
+  __ SmiCompare(rbx, Smi::FromInt(JSGeneratorObject::kReturn));
+  __ j(less, &resume);
   __ Push(result_register());
+  __ j(greater, &exception);
   EmitCreateIteratorResult(true);
   EmitUnwindAndReturn();
 
+  __ bind(&exception);
+  __ CallRuntime(Runtime::kThrow);
+
   __ bind(&suspend);
   OperandStackDepthIncrement(1);  // Not popped on this path.
   VisitForAccumulatorValue(expr->generator_object());
@@ -1810,8 +1817,7 @@
   __ j(equal, &post_runtime);
   __ Push(rax);  // generator object
   __ CallRuntime(Runtime::kSuspendJSGeneratorObject, 1);
-  __ movp(context_register(),
-          Operand(rbp, StandardFrameConstants::kContextOffset));
+  RestoreContext();
   __ bind(&post_runtime);
 
   PopOperand(result_register());
@@ -1821,102 +1827,6 @@
   context()->Plug(result_register());
 }
 
-
-void FullCodeGenerator::EmitGeneratorResume(
-    Expression* generator, Expression* value,
-    JSGeneratorObject::ResumeMode resume_mode) {
-  // The value stays in rax, and is ultimately read by the resumed generator, as
-  // if CallRuntime(Runtime::kSuspendJSGeneratorObject) returned it. Or it
-  // is read to throw the value when the resumed generator is already closed.
-  // rbx will hold the generator object until the activation has been resumed.
-  VisitForStackValue(generator);
-  VisitForAccumulatorValue(value);
-  PopOperand(rbx);
-
-  // Store input value into generator object.
-  __ movp(FieldOperand(rbx, JSGeneratorObject::kInputOffset),
-          result_register());
-  __ movp(rcx, result_register());
-  __ RecordWriteField(rbx, JSGeneratorObject::kInputOffset, rcx, rdx,
-                      kDontSaveFPRegs);
-
-  // Load suspended function and context.
-  __ movp(rsi, FieldOperand(rbx, JSGeneratorObject::kContextOffset));
-  __ movp(rdi, FieldOperand(rbx, JSGeneratorObject::kFunctionOffset));
-
-  // Push receiver.
-  __ Push(FieldOperand(rbx, JSGeneratorObject::kReceiverOffset));
-
-  // Push holes for arguments to generator function. Since the parser forced
-  // context allocation for any variables in generators, the actual argument
-  // values have already been copied into the context and these dummy values
-  // will never be used.
-  __ movp(rdx, FieldOperand(rdi, JSFunction::kSharedFunctionInfoOffset));
-  __ LoadSharedFunctionInfoSpecialField(rdx, rdx,
-      SharedFunctionInfo::kFormalParameterCountOffset);
-  __ LoadRoot(rcx, Heap::kTheHoleValueRootIndex);
-  Label push_argument_holes, push_frame;
-  __ bind(&push_argument_holes);
-  __ subp(rdx, Immediate(1));
-  __ j(carry, &push_frame);
-  __ Push(rcx);
-  __ jmp(&push_argument_holes);
-
-  // Enter a new JavaScript frame, and initialize its slots as they were when
-  // the generator was suspended.
-  Label resume_frame, done;
-  __ bind(&push_frame);
-  __ call(&resume_frame);
-  __ jmp(&done);
-  __ bind(&resume_frame);
-  __ pushq(rbp);  // Caller's frame pointer.
-  __ movp(rbp, rsp);
-  __ Push(rsi);  // Callee's context.
-  __ Push(rdi);  // Callee's JS Function.
-
-  // Load the operand stack size.
-  __ movp(rdx, FieldOperand(rbx, JSGeneratorObject::kOperandStackOffset));
-  __ movp(rdx, FieldOperand(rdx, FixedArray::kLengthOffset));
-  __ SmiToInteger32(rdx, rdx);
-
-  // If we are sending a value and there is no operand stack, we can jump back
-  // in directly.
-  if (resume_mode == JSGeneratorObject::NEXT) {
-    Label slow_resume;
-    __ cmpp(rdx, Immediate(0));
-    __ j(not_zero, &slow_resume);
-    __ movp(rdx, FieldOperand(rdi, JSFunction::kCodeEntryOffset));
-    __ SmiToInteger64(rcx,
-        FieldOperand(rbx, JSGeneratorObject::kContinuationOffset));
-    __ addp(rdx, rcx);
-    __ Move(FieldOperand(rbx, JSGeneratorObject::kContinuationOffset),
-            Smi::FromInt(JSGeneratorObject::kGeneratorExecuting));
-    __ Push(Smi::FromInt(resume_mode));  // Consumed in continuation.
-    __ jmp(rdx);
-    __ bind(&slow_resume);
-  }
-
-  // Otherwise, we push holes for the operand stack and call the runtime to fix
-  // up the stack and the handlers.
-  Label push_operand_holes, call_resume;
-  __ bind(&push_operand_holes);
-  __ subp(rdx, Immediate(1));
-  __ j(carry, &call_resume);
-  __ Push(rcx);
-  __ jmp(&push_operand_holes);
-  __ bind(&call_resume);
-  __ Push(Smi::FromInt(resume_mode));  // Consumed in continuation.
-  __ Push(rbx);
-  __ Push(result_register());
-  __ Push(Smi::FromInt(resume_mode));
-  __ CallRuntime(Runtime::kResumeJSGeneratorObject);
-  // Not reached: the runtime call returns elsewhere.
-  __ Abort(kGeneratorFailedToResume);
-
-  __ bind(&done);
-  context()->Plug(result_register());
-}
-
 void FullCodeGenerator::PushOperand(MemOperand operand) {
   OperandStackDepthIncrement(1);
   __ Push(operand);
@@ -1936,7 +1846,8 @@
 void FullCodeGenerator::EmitCreateIteratorResult(bool done) {
   Label allocate, done_allocate;
 
-  __ Allocate(JSIteratorResult::kSize, rax, rcx, rdx, &allocate, TAG_OBJECT);
+  __ Allocate(JSIteratorResult::kSize, rax, rcx, rdx, &allocate,
+              NO_ALLOCATION_FLAGS);
   __ jmp(&done_allocate, Label::kNear);
 
   __ bind(&allocate);
@@ -2222,8 +2133,7 @@
     __ bind(&uninitialized_this);
     EmitStoreToStackLocalOrContextSlot(var, location);
 
-  } else if (!var->is_const_mode() ||
-             (var->mode() == CONST && op == Token::INIT)) {
+  } else if (!var->is_const_mode() || op == Token::INIT) {
     if (var->IsLookupSlot()) {
       // Assignment to var.
       __ Push(var->name());
@@ -2245,25 +2155,6 @@
       EmitStoreToStackLocalOrContextSlot(var, location);
     }
 
-  } else if (var->mode() == CONST_LEGACY && op == Token::INIT) {
-    // Const initializers need a write barrier.
-    DCHECK(!var->IsParameter());  // No const parameters.
-    if (var->IsLookupSlot()) {
-      __ Push(rax);
-      __ Push(rsi);
-      __ Push(var->name());
-      __ CallRuntime(Runtime::kInitializeLegacyConstLookupSlot);
-    } else {
-      DCHECK(var->IsStackLocal() || var->IsContextSlot());
-      Label skip;
-      MemOperand location = VarOperand(var, rcx);
-      __ movp(rdx, location);
-      __ CompareRoot(rdx, Heap::kTheHoleValueRootIndex);
-      __ j(not_equal, &skip);
-      EmitStoreToStackLocalOrContextSlot(var, location);
-      __ bind(&skip);
-    }
-
   } else {
     DCHECK(var->mode() == CONST_LEGACY && op != Token::INIT);
     if (is_strict(language_mode())) {
@@ -2285,7 +2176,7 @@
   EmitLoadStoreICSlot(expr->AssignmentSlot());
   CallStoreIC();
 
-  PrepareForBailoutForId(expr->AssignmentId(), TOS_REG);
+  PrepareForBailoutForId(expr->AssignmentId(), BailoutState::TOS_REGISTER);
   context()->Plug(rax);
 }
 
@@ -2329,45 +2220,7 @@
   EmitLoadStoreICSlot(expr->AssignmentSlot());
   CallIC(ic);
 
-  PrepareForBailoutForId(expr->AssignmentId(), TOS_REG);
-  context()->Plug(rax);
-}
-
-
-void FullCodeGenerator::VisitProperty(Property* expr) {
-  Comment cmnt(masm_, "[ Property");
-  SetExpressionPosition(expr);
-
-  Expression* key = expr->key();
-
-  if (key->IsPropertyName()) {
-    if (!expr->IsSuperAccess()) {
-      VisitForAccumulatorValue(expr->obj());
-      DCHECK(!rax.is(LoadDescriptor::ReceiverRegister()));
-      __ movp(LoadDescriptor::ReceiverRegister(), rax);
-      EmitNamedPropertyLoad(expr);
-    } else {
-      VisitForStackValue(expr->obj()->AsSuperPropertyReference()->this_var());
-      VisitForStackValue(
-          expr->obj()->AsSuperPropertyReference()->home_object());
-      EmitNamedSuperPropertyLoad(expr);
-    }
-  } else {
-    if (!expr->IsSuperAccess()) {
-      VisitForStackValue(expr->obj());
-      VisitForAccumulatorValue(expr->key());
-      __ Move(LoadDescriptor::NameRegister(), rax);
-      PopOperand(LoadDescriptor::ReceiverRegister());
-      EmitKeyedPropertyLoad(expr);
-    } else {
-      VisitForStackValue(expr->obj()->AsSuperPropertyReference()->this_var());
-      VisitForStackValue(
-          expr->obj()->AsSuperPropertyReference()->home_object());
-      VisitForStackValue(expr->key());
-      EmitKeyedSuperPropertyLoad(expr);
-    }
-  }
-  PrepareForBailoutForId(expr->LoadId(), TOS_REG);
+  PrepareForBailoutForId(expr->AssignmentId(), BailoutState::TOS_REGISTER);
   context()->Plug(rax);
 }
 
@@ -2388,7 +2241,7 @@
   if (callee->IsVariableProxy()) {
     { StackValueContext context(this);
       EmitVariableLoad(callee->AsVariableProxy());
-      PrepareForBailout(callee, NO_REGISTERS);
+      PrepareForBailout(callee, BailoutState::NO_REGISTERS);
     }
     // Push undefined as receiver. This is patched in the Call builtin if it
     // is a sloppy mode method.
@@ -2400,7 +2253,8 @@
     DCHECK(!callee->AsProperty()->IsSuperAccess());
     __ movp(LoadDescriptor::ReceiverRegister(), Operand(rsp, 0));
     EmitNamedPropertyLoad(callee->AsProperty());
-    PrepareForBailoutForId(callee->AsProperty()->LoadId(), TOS_REG);
+    PrepareForBailoutForId(callee->AsProperty()->LoadId(),
+                           BailoutState::TOS_REGISTER);
     // Push the target function under the receiver.
     PushOperand(Operand(rsp, 0));
     __ movp(Operand(rsp, kPointerSize), rax);
@@ -2436,6 +2290,7 @@
   //  - home_object
   //  - key
   CallRuntimeWithOperands(Runtime::kLoadFromSuper);
+  PrepareForBailoutForId(prop->LoadId(), BailoutState::TOS_REGISTER);
 
   // Replace home_object with target function.
   __ movp(Operand(rsp, kPointerSize), rax);
@@ -2460,7 +2315,8 @@
   __ movp(LoadDescriptor::ReceiverRegister(), Operand(rsp, 0));
   __ Move(LoadDescriptor::NameRegister(), rax);
   EmitKeyedPropertyLoad(callee->AsProperty());
-  PrepareForBailoutForId(callee->AsProperty()->LoadId(), TOS_REG);
+  PrepareForBailoutForId(callee->AsProperty()->LoadId(),
+                         BailoutState::TOS_REGISTER);
 
   // Push the target function under the receiver.
   PushOperand(Operand(rsp, 0));
@@ -2493,6 +2349,7 @@
   //  - home_object
   //  - key
   CallRuntimeWithOperands(Runtime::kLoadKeyedFromSuper);
+  PrepareForBailoutForId(prop->LoadId(), BailoutState::TOS_REGISTER);
 
   // Replace home_object with target function.
   __ movp(Operand(rsp, kPointerSize), rax);
@@ -2512,7 +2369,7 @@
     VisitForStackValue(args->at(i));
   }
 
-  PrepareForBailoutForId(expr->CallId(), NO_REGISTERS);
+  PrepareForBailoutForId(expr->CallId(), BailoutState::NO_REGISTERS);
   SetCallPosition(expr, expr->tail_call_mode());
   if (expr->tail_call_mode() == TailCallMode::kAllow) {
     if (FLAG_trace) {
@@ -2533,15 +2390,13 @@
   OperandStackDepthDecrement(arg_count + 1);
 
   RecordJSReturnSite(expr);
-
-  // Restore context register.
-  __ movp(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
+  RestoreContext();
   // Discard the function left on TOS.
   context()->DropAndPlug(1, rax);
 }
 
-
-void FullCodeGenerator::EmitResolvePossiblyDirectEval(int arg_count) {
+void FullCodeGenerator::EmitResolvePossiblyDirectEval(Call* expr) {
+  int arg_count = expr->arguments()->length();
   // Push copy of the first argument or undefined if it doesn't exist.
   if (arg_count > 0) {
     __ Push(Operand(rsp, arg_count * kPointerSize));
@@ -2558,6 +2413,9 @@
   // Push the start position of the scope the calls resides in.
   __ Push(Smi::FromInt(scope()->start_position()));
 
+  // Push the source position of the eval call.
+  __ Push(Smi::FromInt(expr->position()));
+
   // Do the runtime call.
   __ CallRuntime(Runtime::kResolvePossiblyDirectEval);
 }
@@ -2579,7 +2437,7 @@
     __ CallRuntime(Runtime::kLoadLookupSlotForCall);
     PushOperand(rax);  // Function.
     PushOperand(rdx);  // Receiver.
-    PrepareForBailoutForId(expr->LookupId(), NO_REGISTERS);
+    PrepareForBailoutForId(expr->LookupId(), BailoutState::NO_REGISTERS);
 
     // If fast case code has been generated, emit code to push the function
     // and receiver and have the slow path jump around this code.
@@ -2605,7 +2463,7 @@
 
 
 void FullCodeGenerator::EmitPossiblyEvalCall(Call* expr) {
-  // In a call to eval, we first call RuntimeHidden_ResolvePossiblyDirectEval
+  // In a call to eval, we first call Runtime_ResolvePossiblyDirectEval
   // to resolve the function we need to call.  Then we call the resolved
   // function using the given arguments.
   ZoneList<Expression*>* args = expr->arguments();
@@ -2620,12 +2478,12 @@
   // Push a copy of the function (found below the arguments) and resolve
   // eval.
   __ Push(Operand(rsp, (arg_count + 1) * kPointerSize));
-  EmitResolvePossiblyDirectEval(arg_count);
+  EmitResolvePossiblyDirectEval(expr);
 
   // Touch up the callee.
   __ movp(Operand(rsp, (arg_count + 1) * kPointerSize), rax);
 
-  PrepareForBailoutForId(expr->EvalId(), NO_REGISTERS);
+  PrepareForBailoutForId(expr->EvalId(), BailoutState::NO_REGISTERS);
 
   SetCallPosition(expr);
   __ movp(rdi, Operand(rsp, (arg_count + 1) * kPointerSize));
@@ -2635,8 +2493,7 @@
           RelocInfo::CODE_TARGET);
   OperandStackDepthDecrement(arg_count + 1);
   RecordJSReturnSite(expr);
-  // Restore context register.
-  __ movp(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
+  RestoreContext();
   context()->DropAndPlug(1, rax);
 }
 
@@ -2675,9 +2532,8 @@
   CallConstructStub stub(isolate());
   __ Call(stub.GetCode(), RelocInfo::CODE_TARGET);
   OperandStackDepthDecrement(arg_count + 1);
-  PrepareForBailoutForId(expr->ReturnId(), TOS_REG);
-  // Restore context register.
-  __ movp(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
+  PrepareForBailoutForId(expr->ReturnId(), BailoutState::TOS_REGISTER);
+  RestoreContext();
   context()->Plug(rax);
 }
 
@@ -2718,10 +2574,7 @@
   OperandStackDepthDecrement(arg_count + 1);
 
   RecordJSReturnSite(expr);
-
-  // Restore context register.
-  __ movp(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
-
+  RestoreContext();
   context()->Plug(rax);
 }
 
@@ -3113,7 +2966,7 @@
   for (Expression* const arg : *args) {
     VisitForStackValue(arg);
   }
-  PrepareForBailoutForId(expr->CallId(), NO_REGISTERS);
+  PrepareForBailoutForId(expr->CallId(), BailoutState::NO_REGISTERS);
   // Move target to rdi.
   int const argc = args->length() - 2;
   __ movp(rdi, Operand(rsp, (argc + 1) * kPointerSize));
@@ -3121,8 +2974,7 @@
   __ Set(rax, argc);
   __ Call(isolate()->builtins()->Call(), RelocInfo::CODE_TARGET);
   OperandStackDepthDecrement(argc + 1);
-  // Restore context register.
-  __ movp(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
+  RestoreContext();
   // Discard the function left on TOS.
   context()->DropAndPlug(1, rax);
 }
@@ -3176,12 +3028,6 @@
   context()->Plug(rax);
 }
 
-void FullCodeGenerator::EmitGetOrdinaryHasInstance(CallRuntime* expr) {
-  DCHECK_EQ(0, expr->arguments()->length());
-  __ LoadNativeContextSlot(Context::ORDINARY_HAS_INSTANCE_INDEX, rax);
-  context()->Plug(rax);
-}
-
 void FullCodeGenerator::EmitDebugIsActive(CallRuntime* expr) {
   DCHECK(expr->arguments()->length() == 0);
   ExternalReference debug_is_active =
@@ -3201,7 +3047,8 @@
 
   Label runtime, done;
 
-  __ Allocate(JSIteratorResult::kSize, rax, rcx, rdx, &runtime, TAG_OBJECT);
+  __ Allocate(JSIteratorResult::kSize, rax, rcx, rdx, &runtime,
+              NO_ALLOCATION_FLAGS);
   __ LoadNativeContextSlot(Context::ITERATOR_RESULT_MAP_INDEX, rbx);
   __ movp(FieldOperand(rax, HeapObject::kMapOffset), rbx);
   __ LoadRoot(rbx, Heap::kEmptyFixedArrayRootIndex);
@@ -3241,9 +3088,7 @@
   __ Call(isolate()->builtins()->Call(ConvertReceiverMode::kNullOrUndefined),
           RelocInfo::CODE_TARGET);
   OperandStackDepthDecrement(arg_count + 1);
-
-  // Restore context register.
-  __ movp(rsi, Operand(rbp, StandardFrameConstants::kContextOffset));
+  RestoreContext();
 }
 
 
@@ -3328,7 +3173,8 @@
                         &materialize_true);
         if (!context()->IsAccumulatorValue()) OperandStackDepthIncrement(1);
         __ bind(&materialize_true);
-        PrepareForBailoutForId(expr->MaterializeTrueId(), NO_REGISTERS);
+        PrepareForBailoutForId(expr->MaterializeTrueId(),
+                               BailoutState::NO_REGISTERS);
         if (context()->IsAccumulatorValue()) {
           __ LoadRoot(rax, Heap::kTrueValueRootIndex);
         } else {
@@ -3336,7 +3182,8 @@
         }
         __ jmp(&done, Label::kNear);
         __ bind(&materialize_false);
-        PrepareForBailoutForId(expr->MaterializeFalseId(), NO_REGISTERS);
+        PrepareForBailoutForId(expr->MaterializeFalseId(),
+                               BailoutState::NO_REGISTERS);
         if (context()->IsAccumulatorValue()) {
           __ LoadRoot(rax, Heap::kFalseValueRootIndex);
         } else {
@@ -3435,9 +3282,9 @@
   // We need a second deoptimization point after loading the value
   // in case evaluating the property load my have a side effect.
   if (assign_type == VARIABLE) {
-    PrepareForBailout(expr->expression(), TOS_REG);
+    PrepareForBailout(expr->expression(), BailoutState::TOS_REGISTER);
   } else {
-    PrepareForBailoutForId(prop->LoadId(), TOS_REG);
+    PrepareForBailoutForId(prop->LoadId(), BailoutState::TOS_REGISTER);
   }
 
   // Inline smi case if we are in a loop.
@@ -3490,7 +3337,7 @@
   // Convert old value into a number.
   ToNumberStub convert_stub(isolate());
   __ CallStub(&convert_stub);
-  PrepareForBailoutForId(expr->ToNumberId(), TOS_REG);
+  PrepareForBailoutForId(expr->ToNumberId(), BailoutState::TOS_REGISTER);
 
   // Save result for postfix expressions.
   if (expr->is_postfix()) {
@@ -3538,7 +3385,8 @@
         { EffectContext context(this);
           EmitVariableAssignment(expr->expression()->AsVariableProxy()->var(),
                                  Token::ASSIGN, expr->CountSlot());
-          PrepareForBailoutForId(expr->AssignmentId(), TOS_REG);
+          PrepareForBailoutForId(expr->AssignmentId(),
+                                 BailoutState::TOS_REGISTER);
           context.Plug(rax);
         }
         // For all contexts except kEffect: We have the result on
@@ -3550,7 +3398,8 @@
         // Perform the assignment as if via '='.
         EmitVariableAssignment(expr->expression()->AsVariableProxy()->var(),
                                Token::ASSIGN, expr->CountSlot());
-        PrepareForBailoutForId(expr->AssignmentId(), TOS_REG);
+        PrepareForBailoutForId(expr->AssignmentId(),
+                               BailoutState::TOS_REGISTER);
         context()->Plug(rax);
       }
       break;
@@ -3560,7 +3409,7 @@
       PopOperand(StoreDescriptor::ReceiverRegister());
       EmitLoadStoreICSlot(expr->CountSlot());
       CallStoreIC();
-      PrepareForBailoutForId(expr->AssignmentId(), TOS_REG);
+      PrepareForBailoutForId(expr->AssignmentId(), BailoutState::TOS_REGISTER);
       if (expr->is_postfix()) {
         if (!context()->IsEffect()) {
           context()->PlugTOS();
@@ -3599,7 +3448,7 @@
           CodeFactory::KeyedStoreIC(isolate(), language_mode()).code();
       EmitLoadStoreICSlot(expr->CountSlot());
       CallIC(ic);
-      PrepareForBailoutForId(expr->AssignmentId(), TOS_REG);
+      PrepareForBailoutForId(expr->AssignmentId(), BailoutState::TOS_REGISTER);
       if (expr->is_postfix()) {
         if (!context()->IsEffect()) {
           context()->PlugTOS();
@@ -3695,7 +3544,6 @@
 
 void FullCodeGenerator::VisitCompareOperation(CompareOperation* expr) {
   Comment cmnt(masm_, "[ CompareOperation");
-  SetExpressionPosition(expr);
 
   // First we try a fast inlined version of the compare when one of
   // the operands is a literal.
@@ -3715,7 +3563,8 @@
   switch (op) {
     case Token::IN:
       VisitForStackValue(expr->right());
-      CallRuntimeWithOperands(Runtime::kHasProperty);
+      SetExpressionPosition(expr);
+      EmitHasProperty();
       PrepareForBailoutBeforeSplit(expr, false, NULL, NULL);
       __ CompareRoot(rax, Heap::kTrueValueRootIndex);
       Split(equal, if_true, if_false, fall_through);
@@ -3723,6 +3572,7 @@
 
     case Token::INSTANCEOF: {
       VisitForAccumulatorValue(expr->right());
+      SetExpressionPosition(expr);
       PopOperand(rdx);
       InstanceOfStub stub(isolate());
       __ CallStub(&stub);
@@ -3734,6 +3584,7 @@
 
     default: {
       VisitForAccumulatorValue(expr->right());
+      SetExpressionPosition(expr);
       Condition cc = CompareIC::ComputeCondition(op);
       PopOperand(rdx);