[turbofan] Introduce DeoptimizeIf And DeoptimizeUnless common operators.

src/compiler/js-native-context-specialization.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler/js-native-context-specialization.h"
 
 #include "src/accessors.h"
 #include "src/code-factory.h"
 #include "src/compilation-dependencies.h"
 #include "src/compiler/access-builder.h"
@@ skipping 90 matching lines @@
 
   // Nothing to do if we have no non-deprecated maps.
   if (access_infos.empty()) return NoChange();
 
   // The final states for every polymorphic branch. We join them with
   // Merge++Phi+EffectPhi at the bottom.
   ZoneVector<Node*> values(zone());
   ZoneVector<Node*> effects(zone());
   ZoneVector<Node*> controls(zone());
 
-  // The list of "exiting" controls, which currently go to a single deoptimize.
-  // TODO(bmeurer): Consider using an IC as fallback.
-  Node* const exit_effect = effect;
-  ZoneVector<Node*> exit_controls(zone());
-
   // Ensure that {index} matches the specified {name} (if {index} is given).
   if (index != nullptr) {
     Node* check = graph()->NewNode(simplified()->ReferenceEqual(Type::Name()),
                                    index, jsgraph()->HeapConstant(name));
-    Node* branch =
-        graph()->NewNode(common()->Branch(BranchHint::kTrue), check, control);
-    exit_controls.push_back(graph()->NewNode(common()->IfFalse(), branch));
-    control = graph()->NewNode(common()->IfTrue(), branch);
+    control = graph()->NewNode(common()->DeoptimizeUnless(), check, frame_state,
+                               effect, control);
+  }
+
+  // Check if {receiver} may be a number.
+  bool receiverissmi_possible = false;
+  for (PropertyAccessInfo const& access_info : access_infos) {
+    if (access_info.receiver_type()->Is(Type::Number())) {
+      receiverissmi_possible = true;
+      break;
+    }
   }
 
   // Ensure that {receiver} is a heap object.
   Node* check = graph()->NewNode(simplified()->ObjectIsSmi(), receiver);
-  Node* branch = graph()->NewNode(common()->Branch(), check, control);
-  control = graph()->NewNode(common()->IfFalse(), branch);
-  Node* receiverissmi_control = graph()->NewNode(common()->IfTrue(), branch);
+  Node* receiverissmi_control = nullptr;
   Node* receiverissmi_effect = effect;
+  if (receiverissmi_possible) {
+    Node* branch = graph()->NewNode(common()->Branch(), check, control);
+    control = graph()->NewNode(common()->IfFalse(), branch);
+    receiverissmi_control = graph()->NewNode(common()->IfTrue(), branch);
+    receiverissmi_effect = effect;
+  } else {
+    control = graph()->NewNode(common()->DeoptimizeIf(), check, frame_state,
+                               effect, control);
+  }
 
   // Load the {receiver} map. The resulting effect is the dominating effect for
   // all (polymorphic) branches.
   Node* receiver_map = effect =
       graph()->NewNode(simplified()->LoadField(AccessBuilder::ForMap()),
                        receiver, effect, control);
 
   // Generate code for the various different property access patterns.
   Node* fallthrough_control = control;
-  for (PropertyAccessInfo const& access_info : access_infos) {
+  for (size_t j = 0; j < access_infos.size(); ++j) {
+    PropertyAccessInfo const& access_info = access_infos[j];
     Node* this_value = value;
     Node* this_receiver = receiver;
     Node* this_effect = effect;
     Node* this_control;
 
     // Perform map check on {receiver}.
     Type* receiver_type = access_info.receiver_type();
     if (receiver_type->Is(Type::String())) {
       // Emit an instance type check for strings.
       Node* receiver_instance_type = this_effect = graph()->NewNode(
           simplified()->LoadField(AccessBuilder::ForMapInstanceType()),
           receiver_map, this_effect, fallthrough_control);
       Node* check =
           graph()->NewNode(machine()->Uint32LessThan(), receiver_instance_type,
                            jsgraph()->Uint32Constant(FIRST_NONSTRING_TYPE));
-      Node* branch =
-          graph()->NewNode(common()->Branch(), check, fallthrough_control);
-      fallthrough_control = graph()->NewNode(common()->IfFalse(), branch);
-      this_control = graph()->NewNode(common()->IfTrue(), branch);
+      if (j == access_infos.size() - 1) {
+        this_control =
+            graph()->NewNode(common()->DeoptimizeUnless(), check, frame_state,
+                             this_effect, fallthrough_control);
+        fallthrough_control = nullptr;
+      } else {
+        Node* branch =
+            graph()->NewNode(common()->Branch(), check, fallthrough_control);
+        fallthrough_control = graph()->NewNode(common()->IfFalse(), branch);
+        this_control = graph()->NewNode(common()->IfTrue(), branch);
+      }
     } else {
       // Emit a (sequence of) map checks for other {receiver}s.
       ZoneVector<Node*> this_controls(zone());
       ZoneVector<Node*> this_effects(zone());
+      int num_classes = access_info.receiver_type()->NumClasses();
       for (auto i = access_info.receiver_type()->Classes(); !i.Done();
            i.Advance()) {
+        DCHECK_LT(0, num_classes);
         Handle<Map> map = i.Current();
         Node* check =
             graph()->NewNode(simplified()->ReferenceEqual(Type::Internal()),
                              receiver_map, jsgraph()->Constant(map));
-        Node* branch =
-            graph()->NewNode(common()->Branch(), check, fallthrough_control);
-        fallthrough_control = graph()->NewNode(common()->IfFalse(), branch);
-        this_controls.push_back(graph()->NewNode(common()->IfTrue(), branch));
-        this_effects.push_back(this_effect);
+        if (--num_classes == 0 && j == access_infos.size() - 1) {
+          this_controls.push_back(
+              graph()->NewNode(common()->DeoptimizeUnless(), check, frame_state,
+                               this_effect, fallthrough_control));
+          this_effects.push_back(this_effect);
+          fallthrough_control = nullptr;
+        } else {
+          Node* branch =
+              graph()->NewNode(common()->Branch(), check, fallthrough_control);
+          fallthrough_control = graph()->NewNode(common()->IfFalse(), branch);
+          this_controls.push_back(graph()->NewNode(common()->IfTrue(), branch));
+          this_effects.push_back(this_effect);
+        }
       }
 
       // The Number case requires special treatment to also deal with Smis.
       if (receiver_type->Is(Type::Number())) {
-        // Join this check with the "receiver is smi" check above, and mark the
-        // "receiver is smi" check as "consumed" so that we don't deoptimize if
-        // the {receiver} is actually a Smi.
-        if (receiverissmi_control != nullptr) {
-          this_controls.push_back(receiverissmi_control);
-          this_effects.push_back(receiverissmi_effect);
-          receiverissmi_control = receiverissmi_effect = nullptr;
-        }
+        // Join this check with the "receiver is smi" check above.
+        DCHECK_NOT_NULL(receiverissmi_effect);
+        DCHECK_NOT_NULL(receiverissmi_control);
+        this_effects.push_back(receiverissmi_effect);
+        this_controls.push_back(receiverissmi_control);
+        receiverissmi_effect = receiverissmi_control = nullptr;
       }
 
       // Create dominating Merge+EffectPhi for this {receiver} type.
       int const this_control_count = static_cast<int>(this_controls.size());
       this_control =
           (this_control_count == 1)
               ? this_controls.front()
               : graph()->NewNode(common()->Merge(this_control_count),
                                  this_control_count, &this_controls.front());
       this_effects.push_back(this_control);
       int const this_effect_count = static_cast<int>(this_effects.size());
       this_effect =
           (this_control_count == 1)
               ? this_effects.front()
               : graph()->NewNode(common()->EffectPhi(this_control_count),
                                  this_effect_count, &this_effects.front());
     }
 
     // Determine actual holder and perform prototype chain checks.
     Handle<JSObject> holder;
     if (access_info.holder().ToHandle(&holder)) {
       AssumePrototypesStable(receiver_type, native_context, holder);
     }
 
     // Generate the actual property access.
     if (access_info.IsNotFound()) {
       DCHECK_EQ(AccessMode::kLoad, access_mode);
-      if (is_strong(language_mode)) {
-        // TODO(bmeurer/mstarzinger): Add support for lowering inside try
-        // blocks rewiring the IfException edge to a runtime call/throw.
-        exit_controls.push_back(this_control);
-        continue;
-      } else {
-        this_value = jsgraph()->UndefinedConstant();
-      }
+      this_value = jsgraph()->UndefinedConstant();
     } else if (access_info.IsDataConstant()) {
       this_value = jsgraph()->Constant(access_info.constant());
       if (access_mode == AccessMode::kStore) {
         Node* check = graph()->NewNode(
             simplified()->ReferenceEqual(Type::Tagged()), value, this_value);
-        Node* branch = graph()->NewNode(common()->Branch(BranchHint::kTrue),
-                                        check, this_control);
-        exit_controls.push_back(graph()->NewNode(common()->IfFalse(), branch));
-        this_control = graph()->NewNode(common()->IfTrue(), branch);
+        this_control = graph()->NewNode(common()->DeoptimizeUnless(), check,
+                                        frame_state, this_effect, this_control);
       }
     } else {
       DCHECK(access_info.IsDataField());
       FieldIndex const field_index = access_info.field_index();
       FieldCheck const field_check = access_info.field_check();
       Type* const field_type = access_info.field_type();
       switch (field_check) {
         case FieldCheck::kNone:
           break;
         case FieldCheck::kJSArrayBufferViewBufferNotNeutered: {
           Node* this_buffer = this_effect =
               graph()->NewNode(simplified()->LoadField(
                                    AccessBuilder::ForJSArrayBufferViewBuffer()),
                                this_receiver, this_effect, this_control);
           Node* this_buffer_bit_field = this_effect =
               graph()->NewNode(simplified()->LoadField(
                                    AccessBuilder::ForJSArrayBufferBitField()),
                                this_buffer, this_effect, this_control);
           Node* check = graph()->NewNode(
               machine()->Word32Equal(),
               graph()->NewNode(machine()->Word32And(), this_buffer_bit_field,
                                jsgraph()->Int32Constant(
                                    1 << JSArrayBuffer::WasNeutered::kShift)),
               jsgraph()->Int32Constant(0));
-          Node* branch = graph()->NewNode(common()->Branch(BranchHint::kFalse),
-                                          check, this_control);
-          exit_controls.push_back(graph()->NewNode(common()->IfTrue(), branch));
-          this_control = graph()->NewNode(common()->IfFalse(), branch);
+          this_control =
+              graph()->NewNode(common()->DeoptimizeIf(), check, frame_state,
+                               this_effect, this_control);
           break;
         }
       }
       if (access_mode == AccessMode::kLoad &&
           access_info.holder().ToHandle(&holder)) {
         this_receiver = jsgraph()->Constant(holder);
       }
       Node* this_storage = this_receiver;
       if (!field_index.is_inobject()) {
         this_storage = this_effect = graph()->NewNode(
@@ skipping 15 matching lines @@
           field_access.machine_type = MachineType::Float64();
         }
         this_value = this_effect =
             graph()->NewNode(simplified()->LoadField(field_access),
                              this_storage, this_effect, this_control);
       } else {
         DCHECK_EQ(AccessMode::kStore, access_mode);
         if (field_type->Is(Type::UntaggedFloat64())) {
           Node* check =
               graph()->NewNode(simplified()->ObjectIsNumber(), this_value);
-          Node* branch = graph()->NewNode(common()->Branch(BranchHint::kTrue),
-                                          check, this_control);
-          exit_controls.push_back(
-              graph()->NewNode(common()->IfFalse(), branch));
-          this_control = graph()->NewNode(common()->IfTrue(), branch);
+          this_control =
+              graph()->NewNode(common()->DeoptimizeUnless(), check, frame_state,
+                               this_effect, this_control);
           this_value = graph()->NewNode(common()->Guard(Type::Number()),
                                         this_value, this_control);
 
           if (!field_index.is_inobject() || field_index.is_hidden_field() ||
               !FLAG_unbox_double_fields) {
             if (access_info.HasTransitionMap()) {
               // Allocate a MutableHeapNumber for the new property.
               Callable callable =
                   CodeFactory::AllocateMutableHeapNumber(isolate());
               CallDescriptor* desc = Linkage::GetStubCallDescriptor(
@@ skipping 18 matching lines @@
               field_access.name = MaybeHandle<Name>();
               field_access.machine_type = MachineType::Float64();
             }
           } else {
             // Unboxed double field, we store directly to the field.
             field_access.machine_type = MachineType::Float64();
           }
         } else if (field_type->Is(Type::TaggedSigned())) {
           Node* check =
               graph()->NewNode(simplified()->ObjectIsSmi(), this_value);
-          Node* branch = graph()->NewNode(common()->Branch(BranchHint::kTrue),
-                                          check, this_control);
-          exit_controls.push_back(
-              graph()->NewNode(common()->IfFalse(), branch));
-          this_control = graph()->NewNode(common()->IfTrue(), branch);
+          this_control =
+              graph()->NewNode(common()->DeoptimizeUnless(), check, frame_state,
+                               this_effect, this_control);
           this_value = graph()->NewNode(common()->Guard(type_cache_.kSmi),
                                         this_value, this_control);
         } else if (field_type->Is(Type::TaggedPointer())) {
           Node* check =
               graph()->NewNode(simplified()->ObjectIsSmi(), this_value);
-          Node* branch = graph()->NewNode(common()->Branch(BranchHint::kFalse),
-                                          check, this_control);
-          exit_controls.push_back(graph()->NewNode(common()->IfTrue(), branch));
-          this_control = graph()->NewNode(common()->IfFalse(), branch);
-          if (field_type->NumClasses() > 0) {
-            // Emit a (sequence of) map checks for the value.
-            ZoneVector<Node*> this_controls(zone());
+          this_control =
+              graph()->NewNode(common()->DeoptimizeIf(), check, frame_state,
+                               this_effect, this_control);
+          if (field_type->NumClasses() == 1) {
+            // Emit a map check for the value.
             Node* this_value_map = this_effect = graph()->NewNode(
                 simplified()->LoadField(AccessBuilder::ForMap()), this_value,
                 this_effect, this_control);
-            for (auto i = field_type->Classes(); !i.Done(); i.Advance()) {
-              Handle<Map> field_map(i.Current());
-              check = graph()->NewNode(
-                  simplified()->ReferenceEqual(Type::Internal()),
-                  this_value_map, jsgraph()->Constant(field_map));
-              branch = graph()->NewNode(common()->Branch(BranchHint::kTrue),
-                                        check, this_control);
-              this_control = graph()->NewNode(common()->IfFalse(), branch);
-              this_controls.push_back(
-                  graph()->NewNode(common()->IfTrue(), branch));
-            }
-            exit_controls.push_back(this_control);
-            int const this_control_count =
-                static_cast<int>(this_controls.size());
+            Node* check = graph()->NewNode(
+                simplified()->ReferenceEqual(Type::Internal()), this_value_map,
+                jsgraph()->Constant(field_type->Classes().Current()));
             this_control =
-                (this_control_count == 1)
-                    ? this_controls.front()
-                    : graph()->NewNode(common()->Merge(this_control_count),
-                                       this_control_count,
-                                       &this_controls.front());
+                graph()->NewNode(common()->DeoptimizeUnless(), check,
+                                 frame_state, this_effect, this_control);
+          } else {
+            DCHECK_EQ(0, field_type->NumClasses());
           }
         } else {
           DCHECK(field_type->Is(Type::Tagged()));
         }
         Handle<Map> transition_map;
         if (access_info.transition_map().ToHandle(&transition_map)) {
           this_effect = graph()->NewNode(common()->BeginRegion(), this_effect);
           this_effect = graph()->NewNode(
               simplified()->StoreField(AccessBuilder::ForMap()), this_receiver,
               jsgraph()->Constant(transition_map), this_effect, this_control);
         }
         this_effect = graph()->NewNode(simplified()->StoreField(field_access),
                                        this_storage, this_value, this_effect,
                                        this_control);
         if (access_info.HasTransitionMap()) {
           this_effect =
               graph()->NewNode(common()->FinishRegion(),
                                jsgraph()->UndefinedConstant(), this_effect);
         }
       }
     }
 
     // Remember the final state for this property access.
     values.push_back(this_value);
     effects.push_back(this_effect);
     controls.push_back(this_control);
   }
 
-  // Collect the fallthrough control as final "exit" control.
-  if (fallthrough_control != control) {
-    // Mark the last fallthrough branch as deferred.
-    MarkAsDeferred(fallthrough_control);
-  }
-  exit_controls.push_back(fallthrough_control);
-
-  // Also collect the "receiver is smi" control if we didn't handle the case of
-  // Number primitives in the polymorphic branches above.
-  if (receiverissmi_control != nullptr) {
-    // Mark the "receiver is smi" case as deferred.
-    MarkAsDeferred(receiverissmi_control);
-    DCHECK_EQ(exit_effect, receiverissmi_effect);
-    exit_controls.push_back(receiverissmi_control);
-  }
-
-  // Generate the single "exit" point, where we get if either all map/instance
-  // type checks failed, or one of the assumptions inside one of the cases
-  // failes (i.e. failing prototype chain check).
-  // TODO(bmeurer): Consider falling back to IC here if deoptimization is
-  // disabled.
-  int const exit_control_count = static_cast<int>(exit_controls.size());
-  Node* exit_control =
-      (exit_control_count == 1)
-          ? exit_controls.front()
-          : graph()->NewNode(common()->Merge(exit_control_count),
-                             exit_control_count, &exit_controls.front());
-  Node* deoptimize =
-      graph()->NewNode(common()->Deoptimize(DeoptimizeKind::kEager),
-                       frame_state, exit_effect, exit_control);
-  // TODO(bmeurer): This should be on the AdvancedReducer somehow.
-  NodeProperties::MergeControlToEnd(graph(), common(), deoptimize);
-  Revisit(graph()->end());
+  DCHECK_NULL(fallthrough_control);
 
   // Generate the final merge point for all (polymorphic) branches.
   int const control_count = static_cast<int>(controls.size());
   if (control_count == 0) {
     value = effect = control = jsgraph()->Dead();
   } else if (control_count == 1) {
     value = values.front();
     effect = effects.front();
     control = controls.front();
   } else {
@@ skipping 106 matching lines @@
 
   // Nothing to do if we have no non-deprecated maps.
   if (access_infos.empty()) return NoChange();
 
   // The final states for every polymorphic branch. We join them with
   // Merge+Phi+EffectPhi at the bottom.
   ZoneVector<Node*> values(zone());
   ZoneVector<Node*> effects(zone());
   ZoneVector<Node*> controls(zone());
 
-  // The list of "exiting" controls, which currently go to a single deoptimize.
-  // TODO(bmeurer): Consider using an IC as fallback.
-  Node* const exit_effect = effect;
-  ZoneVector<Node*> exit_controls(zone());
-
   // Ensure that {receiver} is a heap object.
   Node* check = graph()->NewNode(simplified()->ObjectIsSmi(), receiver);
-  Node* branch =
-      graph()->NewNode(common()->Branch(BranchHint::kFalse), check, control);
-  exit_controls.push_back(graph()->NewNode(common()->IfTrue(), branch));
-  control = graph()->NewNode(common()->IfFalse(), branch);
+  control = graph()->NewNode(common()->DeoptimizeIf(), check, frame_state,
+                             effect, control);
 
   // Load the {receiver} map. The resulting effect is the dominating effect for
   // all (polymorphic) branches.
   Node* receiver_map = effect =
       graph()->NewNode(simplified()->LoadField(AccessBuilder::ForMap()),
                        receiver, effect, control);
 
   // Generate code for the various different element access patterns.
   Node* fallthrough_control = control;
-  for (ElementAccessInfo const& access_info : access_infos) {
+  for (size_t j = 0; j < access_infos.size(); ++j) {
+    ElementAccessInfo const& access_info = access_infos[j];
     Node* this_receiver = receiver;
     Node* this_value = value;
     Node* this_index = index;
     Node* this_effect;
     Node* this_control;
 
     // Perform map check on {receiver}.
     Type* receiver_type = access_info.receiver_type();
     bool receiver_is_jsarray = true;
     {
       ZoneVector<Node*> this_controls(zone());
       ZoneVector<Node*> this_effects(zone());
+      size_t num_transitions = access_info.transitions().size();
+      int num_classes = access_info.receiver_type()->NumClasses();
       for (auto i = access_info.receiver_type()->Classes(); !i.Done();
            i.Advance()) {
+        DCHECK_LT(0, num_classes);
         Handle<Map> map = i.Current();
         Node* check =
             graph()->NewNode(simplified()->ReferenceEqual(Type::Any()),
                              receiver_map, jsgraph()->Constant(map));
-        Node* branch =
-            graph()->NewNode(common()->Branch(), check, fallthrough_control);
-        this_controls.push_back(graph()->NewNode(common()->IfTrue(), branch));
+        if (--num_classes == 0 && num_transitions == 0 &&

[Jarin, 2016/02/24 08:56:38]

Side-effect in shortcut operators, what could possibly go wrong?

[Benedikt Meurer, 2016/02/24 09:04:56]

Acknowledged.

+            j == access_infos.size() - 1) {
+          this_controls.push_back(graph()->NewNode(common()->DeoptimizeUnless(),

[Jarin, 2016/02/24 08:56:38]

Please, add a comment explaining what you are doing here. (I assume this is
handling the last conditional in the chain and the black magic with the counts
is there just to track which one is the last one).

[Benedikt Meurer, 2016/02/24 09:04:56]

Done.

+                                                   check, frame_state, effect,
+                                                   fallthrough_control));
+          fallthrough_control = nullptr;
+        } else {
+          Node* branch =
+              graph()->NewNode(common()->Branch(), check, fallthrough_control);
+          this_controls.push_back(graph()->NewNode(common()->IfTrue(), branch));
+          fallthrough_control = graph()->NewNode(common()->IfFalse(), branch);
+        }
         this_effects.push_back(effect);
-        fallthrough_control = graph()->NewNode(common()->IfFalse(), branch);
         if (!map->IsJSArrayMap()) receiver_is_jsarray = false;
       }
 
       // Generate possible elements kind transitions.
       for (auto transition : access_info.transitions()) {
+        DCHECK_LT(0u, num_transitions);
         Handle<Map> transition_source = transition.first;
         Handle<Map> transition_target = transition.second;
+        Node* transition_control;
+        Node* transition_effect = effect;
 
         // Check if {receiver} has the specified {transition_source} map.
         Node* check = graph()->NewNode(
             simplified()->ReferenceEqual(Type::Any()), receiver_map,
             jsgraph()->HeapConstant(transition_source));
-        Node* branch =
-            graph()->NewNode(common()->Branch(), check, fallthrough_control);
+        if (--num_transitions == 0 && j == access_infos.size() - 1) {
+          transition_control =
+              graph()->NewNode(common()->DeoptimizeUnless(), check, frame_state,
+                               transition_effect, fallthrough_control);
+          fallthrough_control = nullptr;
+        } else {
+          Node* branch =
+              graph()->NewNode(common()->Branch(), check, fallthrough_control);
+          fallthrough_control = graph()->NewNode(common()->IfFalse(), branch);
+          transition_control = graph()->NewNode(common()->IfTrue(), branch);
+        }
 
         // Migrate {receiver} from {transition_source} to {transition_target}.
-        Node* transition_control = graph()->NewNode(common()->IfTrue(), branch);
-        Node* transition_effect = effect;
         if (IsSimpleMapChangeTransition(transition_source->elements_kind(),
                                         transition_target->elements_kind())) {
           // In-place migration, just store the {transition_target} map.
           transition_effect = graph()->NewNode(
               simplified()->StoreField(AccessBuilder::ForMap()), receiver,
               jsgraph()->HeapConstant(transition_target), transition_effect,
               transition_control);
         } else {
           // Instance migration, let the stub deal with the {receiver}.
           TransitionElementsKindStub stub(isolate(),
                                           transition_source->elements_kind(),
                                           transition_target->elements_kind(),
                                           transition_source->IsJSArrayMap());
           CallDescriptor const* const desc = Linkage::GetStubCallDescriptor(
               isolate(), graph()->zone(), stub.GetCallInterfaceDescriptor(), 0,
               CallDescriptor::kNeedsFrameState, node->op()->properties());
           transition_effect = graph()->NewNode(
               common()->Call(desc), jsgraph()->HeapConstant(stub.GetCode()),
               receiver, jsgraph()->HeapConstant(transition_target), context,
               frame_state, transition_effect, transition_control);
         }
         this_controls.push_back(transition_control);
         this_effects.push_back(transition_effect);
-
-        fallthrough_control = graph()->NewNode(common()->IfFalse(), branch);
       }
 
       // Create single chokepoint for the control.
       int const this_control_count = static_cast<int>(this_controls.size());
       if (this_control_count == 1) {
         this_control = this_controls.front();
         this_effect = this_effects.front();
       } else {
         this_control =
             graph()->NewNode(common()->Merge(this_control_count),
@@ skipping 10 matching lines @@
     // not compatible with (monomorphic) keyed stores.
     Handle<JSObject> holder;
     if (access_info.holder().ToHandle(&holder)) {
       AssumePrototypesStable(receiver_type, native_context, holder);
     }
 
     // Check that the {index} is actually a Number.
     if (!NumberMatcher(this_index).HasValue()) {
       Node* check =
           graph()->NewNode(simplified()->ObjectIsNumber(), this_index);
-      Node* branch = graph()->NewNode(common()->Branch(BranchHint::kTrue),
-                                      check, this_control);
-      exit_controls.push_back(graph()->NewNode(common()->IfFalse(), branch));
-      this_control = graph()->NewNode(common()->IfTrue(), branch);
+      this_control = graph()->NewNode(common()->DeoptimizeUnless(), check,
+                                      frame_state, this_effect, this_control);
       this_index = graph()->NewNode(common()->Guard(Type::Number()), this_index,
                                     this_control);
     }
 
     // Convert the {index} to an unsigned32 value and check if the result is
     // equal to the original {index}.
     if (!NumberMatcher(this_index).IsInRange(0.0, kMaxUInt32)) {
       Node* this_index32 =
           graph()->NewNode(simplified()->NumberToUint32(), this_index);
       Node* check = graph()->NewNode(simplified()->NumberEqual(), this_index32,
                                      this_index);
-      Node* branch = graph()->NewNode(common()->Branch(BranchHint::kTrue),
-                                      check, this_control);
-      exit_controls.push_back(graph()->NewNode(common()->IfFalse(), branch));
-      this_control = graph()->NewNode(common()->IfTrue(), branch);
+      this_control = graph()->NewNode(common()->DeoptimizeUnless(), check,
+                                      frame_state, this_effect, this_control);
       this_index = this_index32;
     }
 
     // TODO(bmeurer): We currently specialize based on elements kind. We should
     // also be able to properly support strings and other JSObjects here.
     ElementsKind elements_kind = access_info.elements_kind();
 
     // Load the elements for the {receiver}.
     Node* this_elements = this_effect = graph()->NewNode(
         simplified()->LoadField(AccessBuilder::ForJSObjectElements()),
         this_receiver, this_effect, this_control);
 
     // Don't try to store to a copy-on-write backing store.
     if (access_mode == AccessMode::kStore &&
         IsFastSmiOrObjectElementsKind(elements_kind)) {
       Node* this_elements_map = this_effect =
           graph()->NewNode(simplified()->LoadField(AccessBuilder::ForMap()),
                            this_elements, this_effect, this_control);
-      check = graph()->NewNode(
+      Node* check = graph()->NewNode(
           simplified()->ReferenceEqual(Type::Any()), this_elements_map,
           jsgraph()->HeapConstant(factory()->fixed_array_map()));
-      branch = graph()->NewNode(common()->Branch(BranchHint::kTrue), check,
-                                this_control);
-      exit_controls.push_back(graph()->NewNode(common()->IfFalse(), branch));
-      this_control = graph()->NewNode(common()->IfTrue(), branch);
+      this_control = graph()->NewNode(common()->DeoptimizeUnless(), check,
+                                      frame_state, this_effect, this_control);
     }
 
     // Load the length of the {receiver}.
     Node* this_length = this_effect =
         receiver_is_jsarray
             ? graph()->NewNode(
                   simplified()->LoadField(
                       AccessBuilder::ForJSArrayLength(elements_kind)),
                   this_receiver, this_effect, this_control)
             : graph()->NewNode(
                   simplified()->LoadField(AccessBuilder::ForFixedArrayLength()),
                   this_elements, this_effect, this_control);
 
     // Check that the {index} is in the valid range for the {receiver}.
     Node* check = graph()->NewNode(simplified()->NumberLessThan(), this_index,
                                    this_length);
-    Node* branch = graph()->NewNode(common()->Branch(BranchHint::kTrue), check,
-                                    this_control);
-    exit_controls.push_back(graph()->NewNode(common()->IfFalse(), branch));
-    this_control = graph()->NewNode(common()->IfTrue(), branch);
+    this_control = graph()->NewNode(common()->DeoptimizeUnless(), check,
+                                    frame_state, this_effect, this_control);
 
     // Compute the element access.
     Type* element_type = Type::Any();
     MachineType element_machine_type = MachineType::AnyTagged();
     if (IsFastDoubleElementsKind(elements_kind)) {
       element_type = Type::Number();
       element_machine_type = MachineType::Float64();
     } else if (IsFastSmiElementsKind(elements_kind)) {
       element_type = type_cache_.kSmi;
     }
@@ skipping 18 matching lines @@
           simplified()->LoadElement(element_access), this_elements, this_index,
           this_effect, this_control);
       // Handle loading from holey backing stores correctly, by either mapping
       // the hole to undefined if possible, or deoptimizing otherwise.
       if (elements_kind == FAST_HOLEY_ELEMENTS ||
           elements_kind == FAST_HOLEY_SMI_ELEMENTS) {
         // Perform the hole check on the result.
         Node* check =
             graph()->NewNode(simplified()->ReferenceEqual(element_access.type),
                              this_value, jsgraph()->TheHoleConstant());
-        Node* branch = graph()->NewNode(common()->Branch(BranchHint::kFalse),
-                                        check, this_control);
-        Node* if_true = graph()->NewNode(common()->IfTrue(), branch);
-        Node* if_false = graph()->NewNode(common()->IfFalse(), branch);
         // Check if we are allowed to turn the hole into undefined.
         Type* initial_holey_array_type = Type::Class(
             handle(isolate()->get_initial_js_array_map(elements_kind)),
             graph()->zone());
         if (receiver_type->NowIs(initial_holey_array_type) &&
             isolate()->IsFastArrayConstructorPrototypeChainIntact()) {
+          Node* branch = graph()->NewNode(common()->Branch(BranchHint::kFalse),
+                                          check, this_control);
+          Node* if_true = graph()->NewNode(common()->IfTrue(), branch);
+          Node* if_false = graph()->NewNode(common()->IfFalse(), branch);
           // Add a code dependency on the array protector cell.
           AssumePrototypesStable(receiver_type, native_context,
                                  isolate()->initial_object_prototype());
           dependencies()->AssumePropertyCell(factory()->array_protector());
           // Turn the hole into undefined.
           this_control =
               graph()->NewNode(common()->Merge(2), if_true, if_false);
           this_value = graph()->NewNode(
               common()->Phi(MachineRepresentation::kTagged, 2),
               jsgraph()->UndefinedConstant(), this_value, this_control);
           element_type =
               Type::Union(element_type, Type::Undefined(), graph()->zone());
         } else {
           // Deoptimize in case of the hole.
-          exit_controls.push_back(if_true);
-          this_control = if_false;
+          this_control =
+              graph()->NewNode(common()->DeoptimizeIf(), check, frame_state,
+                               this_effect, this_control);
         }
         // Rename the result to represent the actual type (not polluted by the
         // hole).
         this_value = graph()->NewNode(common()->Guard(element_type), this_value,
                                       this_control);
       } else if (elements_kind == FAST_HOLEY_DOUBLE_ELEMENTS) {
         // Perform the hole check on the result.
         Node* check =
             graph()->NewNode(simplified()->NumberIsHoleNaN(), this_value);
         // Check if we are allowed to return the hole directly.
         Type* initial_holey_array_type = Type::Class(
             handle(isolate()->get_initial_js_array_map(elements_kind)),
             graph()->zone());
         if (receiver_type->NowIs(initial_holey_array_type) &&
             isolate()->IsFastArrayConstructorPrototypeChainIntact()) {
           // Add a code dependency on the array protector cell.
           AssumePrototypesStable(receiver_type, native_context,
                                  isolate()->initial_object_prototype());
           dependencies()->AssumePropertyCell(factory()->array_protector());
           // Turn the hole into undefined.
           this_value = graph()->NewNode(
               common()->Select(MachineRepresentation::kTagged,
                                BranchHint::kFalse),
               check, jsgraph()->UndefinedConstant(), this_value);
         } else {
           // Deoptimize in case of the hole.
-          Node* branch = graph()->NewNode(common()->Branch(BranchHint::kFalse),
-                                          check, this_control);
-          this_control = graph()->NewNode(common()->IfFalse(), branch);
-          exit_controls.push_back(graph()->NewNode(common()->IfTrue(), branch));
+          this_control =
+              graph()->NewNode(common()->DeoptimizeIf(), check, frame_state,
+                               this_effect, this_control);
         }
       }
     } else {
       DCHECK_EQ(AccessMode::kStore, access_mode);
       if (IsFastSmiElementsKind(elements_kind)) {
         Node* check = graph()->NewNode(simplified()->ObjectIsSmi(), this_value);
-        Node* branch = graph()->NewNode(common()->Branch(BranchHint::kTrue),
-                                        check, this_control);
-        exit_controls.push_back(graph()->NewNode(common()->IfFalse(), branch));
-        this_control = graph()->NewNode(common()->IfTrue(), branch);
+        this_control = graph()->NewNode(common()->DeoptimizeUnless(), check,
+                                        frame_state, this_effect, this_control);
         this_value = graph()->NewNode(common()->Guard(type_cache_.kSmi),
                                       this_value, this_control);
       } else if (IsFastDoubleElementsKind(elements_kind)) {
         Node* check =
             graph()->NewNode(simplified()->ObjectIsNumber(), this_value);
-        Node* branch = graph()->NewNode(common()->Branch(BranchHint::kTrue),
-                                        check, this_control);
-        exit_controls.push_back(graph()->NewNode(common()->IfFalse(), branch));
-        this_control = graph()->NewNode(common()->IfTrue(), branch);
+        this_control = graph()->NewNode(common()->DeoptimizeUnless(), check,
+                                        frame_state, this_effect, this_control);
         this_value = graph()->NewNode(common()->Guard(Type::Number()),
                                       this_value, this_control);
       }
       this_effect = graph()->NewNode(simplified()->StoreElement(element_access),
                                      this_elements, this_index, this_value,
                                      this_effect, this_control);
     }
 
     // Remember the final state for this element access.
     values.push_back(this_value);
     effects.push_back(this_effect);
     controls.push_back(this_control);
   }
 
-  // Collect the fallthrough control as final "exit" control.
-  if (fallthrough_control != control) {
-    // Mark the last fallthrough branch as deferred.
-    MarkAsDeferred(fallthrough_control);
-  }
-  exit_controls.push_back(fallthrough_control);
-
-  // Generate the single "exit" point, where we get if either all map/instance
-  // type checks failed, or one of the assumptions inside one of the cases
-  // failes (i.e. failing prototype chain check).
-  // TODO(bmeurer): Consider falling back to IC here if deoptimization is
-  // disabled.
-  int const exit_control_count = static_cast<int>(exit_controls.size());
-  Node* exit_control =
-      (exit_control_count == 1)
-          ? exit_controls.front()
-          : graph()->NewNode(common()->Merge(exit_control_count),
-                             exit_control_count, &exit_controls.front());
-  Node* deoptimize =
-      graph()->NewNode(common()->Deoptimize(DeoptimizeKind::kEager),
-                       frame_state, exit_effect, exit_control);
-  // TODO(bmeurer): This should be on the AdvancedReducer somehow.
-  NodeProperties::MergeControlToEnd(graph(), common(), deoptimize);
-  Revisit(graph()->end());
+  DCHECK_NULL(fallthrough_control);
 
   // Generate the final merge point for all (polymorphic) branches.
   int const control_count = static_cast<int>(controls.size());
   if (control_count == 0) {
     value = effect = control = jsgraph()->Dead();
   } else if (control_count == 1) {
     value = values.front();
     effect = effects.front();
     control = controls.front();
   } else {
@@ skipping 134 matching lines @@
     Handle<JSFunction> constructor;
     if (Map::GetConstructorFunction(map, native_context)
             .ToHandle(&constructor)) {
       map = handle(constructor->initial_map(), isolate());
     }
     dependencies()->AssumePrototypeMapsStable(map, holder);
   }
 }
 
 
-void JSNativeContextSpecialization::MarkAsDeferred(Node* if_projection) {
-  Node* branch = NodeProperties::GetControlInput(if_projection);
-  DCHECK_EQ(IrOpcode::kBranch, branch->opcode());
-  if (if_projection->opcode() == IrOpcode::kIfTrue) {
-    NodeProperties::ChangeOp(branch, common()->Branch(BranchHint::kFalse));
-  } else {
-    DCHECK_EQ(IrOpcode::kIfFalse, if_projection->opcode());
-    NodeProperties::ChangeOp(branch, common()->Branch(BranchHint::kTrue));
-  }
-}
-
-
 MaybeHandle<Context> JSNativeContextSpecialization::GetNativeContext(
     Node* node) {
   Node* const context = NodeProperties::GetContextInput(node);
   return NodeProperties::GetSpecializationNativeContext(context,
                                                         native_context());
 }
 
 
 Graph* JSNativeContextSpecialization::graph() const {
   return jsgraph()->graph();
@@ skipping 25 matching lines @@
 }
 
 
 SimplifiedOperatorBuilder* JSNativeContextSpecialization::simplified() const {
   return jsgraph()->simplified();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8