VectorICs: Crankshaft adaptations to deal with vector store ics.

src/hydrogen.cc

Index: src/hydrogen.cc
diff --git a/src/hydrogen.cc b/src/hydrogen.cc
index ab037f3a3186c1986f2e4b40c4953f7e77bcc2c3..80546917f13478ccbec9514fee5b2402bd9ae6bd 100644
--- a/src/hydrogen.cc
+++ b/src/hydrogen.cc
@@ -5757,7 +5757,7 @@ void HOptimizedGraphBuilder::VisitObjectLiteral(ObjectLiteral* expr) {
   // The object is expected in the bailout environment during computation
   // of the property values and is the value of the entire expression.
   Push(literal);
-
+  int store_slot_index = 0;
   for (int i = 0; i < expr->properties()->length(); i++) {
     ObjectLiteral::Property* property = expr->properties()->at(i);
     if (property->is_computed_name()) return Bailout(kComputedPropertyName);
@@ -5778,23 +5778,14 @@ void HOptimizedGraphBuilder::VisitObjectLiteral(ObjectLiteral* expr) {
             CHECK_ALIVE(VisitForValue(value));
             HValue* value = Pop();
 
-            // Add [[HomeObject]] to function literals.
-            if (FunctionLiteral::NeedsHomeObject(property->value())) {
-              Handle<Symbol> sym = isolate()->factory()->home_object_symbol();
-              HInstruction* store_home = BuildKeyedGeneric(
-                  STORE, NULL, value, Add<HConstant>(sym), literal);
-              AddInstruction(store_home);
-              DCHECK(store_home->HasObservableSideEffects());
-              Add<HSimulate>(property->value()->id(), REMOVABLE_SIMULATE);
-            }
-
             Handle<Map> map = property->GetReceiverType();
             Handle<String> name = key->AsPropertyName();
             HValue* store;
+            FeedbackVectorICSlot slot = expr->GetNthSlot(store_slot_index++);
             if (map.is_null()) {
               // If we don't know the monomorphic type, do a generic store.
-              CHECK_ALIVE(store = BuildNamedGeneric(
-                  STORE, NULL, literal, name, value));
+              CHECK_ALIVE(store = BuildNamedGeneric(STORE, NULL, slot, literal,
+                                                    name, value));
             } else {
               PropertyAccessInfo info(this, STORE, map, name);
               if (info.CanAccessMonomorphic()) {
@@ -5804,8 +5795,8 @@ void HOptimizedGraphBuilder::VisitObjectLiteral(ObjectLiteral* expr) {
                     &info, literal, checked_literal, value,
                     BailoutId::None(), BailoutId::None());
               } else {
-                CHECK_ALIVE(store = BuildNamedGeneric(
-                    STORE, NULL, literal, name, value));
+                CHECK_ALIVE(store = BuildNamedGeneric(STORE, NULL, slot,
+                                                      literal, name, value));
               }
             }
             if (store->IsInstruction()) {
@@ -5813,6 +5804,17 @@ void HOptimizedGraphBuilder::VisitObjectLiteral(ObjectLiteral* expr) {
             }
             DCHECK(store->HasObservableSideEffects());
             Add<HSimulate>(key->id(), REMOVABLE_SIMULATE);
+
+            // Add [[HomeObject]] to function literals.
+            if (FunctionLiteral::NeedsHomeObject(property->value())) {
+              Handle<Symbol> sym = isolate()->factory()->home_object_symbol();
+              HInstruction* store_home = BuildNamedGeneric(
+                  STORE, NULL, expr->GetNthSlot(store_slot_index++), value, sym,
+                  literal);
+              AddInstruction(store_home);
+              DCHECK(store_home->HasObservableSideEffects());
+              Add<HSimulate>(property->value()->id(), REMOVABLE_SIMULATE);
+            }
           } else {
             CHECK_ALIVE(VisitForEffect(value));
           }
@@ -5827,6 +5829,9 @@ void HOptimizedGraphBuilder::VisitObjectLiteral(ObjectLiteral* expr) {
     }
   }
 
+  // Crankshaft may not consume all the slots because it doesn't emit accessors.
+  DCHECK(!FLAG_vector_stores || store_slot_index <= expr->slot_count());
+
   if (expr->has_function()) {
     // Return the result of the transformation to fast properties
     // instead of the original since this operation changes the map
@@ -6461,9 +6466,9 @@ HValue* HOptimizedGraphBuilder::BuildMonomorphicAccess(
 
 
 void HOptimizedGraphBuilder::HandlePolymorphicNamedFieldAccess(
-    PropertyAccessType access_type, Expression* expr, BailoutId ast_id,
-    BailoutId return_id, HValue* object, HValue* value, SmallMapList* maps,
-    Handle<String> name) {
+    PropertyAccessType access_type, Expression* expr, FeedbackVectorICSlot slot,
+    BailoutId ast_id, BailoutId return_id, HValue* object, HValue* value,
+    SmallMapList* maps, Handle<String> name) {
   // Something did not match; must use a polymorphic load.
   int count = 0;
   HBasicBlock* join = NULL;
@@ -6581,8 +6586,8 @@ void HOptimizedGraphBuilder::HandlePolymorphicNamedFieldAccess(
     FinishExitWithHardDeoptimization(
         Deoptimizer::kUnknownMapInPolymorphicAccess);
   } else {
-    HInstruction* instr = BuildNamedGeneric(access_type, expr, object, name,
-                                            value);
+    HInstruction* instr =
+        BuildNamedGeneric(access_type, expr, slot, object, name, value);
     AddInstruction(instr);
     if (!ast_context()->IsEffect()) Push(access_type == LOAD ? instr : value);
 
@@ -6630,10 +6635,9 @@ static bool AreStringTypes(SmallMapList* maps) {
 }
 
 
-void HOptimizedGraphBuilder::BuildStore(Expression* expr,
-                                        Property* prop,
-                                        BailoutId ast_id,
-                                        BailoutId return_id,
+void HOptimizedGraphBuilder::BuildStore(Expression* expr, Property* prop,
+                                        FeedbackVectorICSlot slot,
+                                        BailoutId ast_id, BailoutId return_id,
                                         bool is_uninitialized) {
   if (!prop->key()->IsPropertyName()) {
     // Keyed store.
@@ -6641,8 +6645,9 @@ void HOptimizedGraphBuilder::BuildStore(Expression* expr,
     HValue* key = Pop();
     HValue* object = Pop();
     bool has_side_effects = false;
-    HValue* result = HandleKeyedElementAccess(
-        object, key, value, expr, ast_id, return_id, STORE, &has_side_effects);
+    HValue* result =
+        HandleKeyedElementAccess(object, key, value, expr, slot, ast_id,
+                                 return_id, STORE, &has_side_effects);
     if (has_side_effects) {
       if (!ast_context()->IsEffect()) Push(value);
       Add<HSimulate>(ast_id, REMOVABLE_SIMULATE);
@@ -6660,8 +6665,8 @@ void HOptimizedGraphBuilder::BuildStore(Expression* expr,
   Handle<String> name = Handle<String>::cast(key->value());
   DCHECK(!name.is_null());
 
-  HValue* access = BuildNamedAccess(STORE, ast_id, return_id, expr, object,
-                                    name, value, is_uninitialized);
+  HValue* access = BuildNamedAccess(STORE, ast_id, return_id, expr, slot,
+                                    object, name, value, is_uninitialized);
   if (access == NULL) return;
 
   if (!ast_context()->IsEffect()) Push(value);
@@ -6682,7 +6687,7 @@ void HOptimizedGraphBuilder::HandlePropertyAssignment(Assignment* expr) {
     CHECK_ALIVE(VisitForValue(prop->key()));
   }
   CHECK_ALIVE(VisitForValue(expr->value()));
-  BuildStore(expr, prop, expr->id(),
+  BuildStore(expr, prop, expr->AssignmentSlot(), expr->id(),
              expr->AssignmentId(), expr->IsUninitialized());
 }
 
@@ -6691,8 +6696,7 @@ void HOptimizedGraphBuilder::HandlePropertyAssignment(Assignment* expr) {
 // superclass of Assignment and CountOperation, we cannot just pass the
 // owning expression instead of position and ast_id separately.
 void HOptimizedGraphBuilder::HandleGlobalVariableAssignment(
-    Variable* var,
-    HValue* value,
+    Variable* var, HValue* value, FeedbackVectorICSlot ic_slot,
     BailoutId ast_id) {
   Handle<GlobalObject> global(current_info()->global_object());
 
@@ -6800,6 +6804,11 @@ void HOptimizedGraphBuilder::HandleGlobalVariableAssignment(
     HStoreNamedGeneric* instr =
         Add<HStoreNamedGeneric>(global_object, var->name(), value,
                                 function_language_mode(), PREMONOMORPHIC);
+    if (FLAG_vector_stores) {
+      Handle<TypeFeedbackVector> vector =
+          handle(current_feedback_vector(), isolate());
+      instr->SetVectorAndSlot(vector, ic_slot);
+    }
     USE(instr);
     DCHECK(instr->HasObservableSideEffects());
     Add<HSimulate>(ast_id, REMOVABLE_SIMULATE);
@@ -6828,8 +6837,7 @@ void HOptimizedGraphBuilder::HandleCompoundAssignment(Assignment* expr) {
     switch (var->location()) {
       case VariableLocation::GLOBAL:
       case VariableLocation::UNALLOCATED:
-        HandleGlobalVariableAssignment(var,
-                                       Top(),
+        HandleGlobalVariableAssignment(var, Top(), expr->AssignmentSlot(),
                                        expr->AssignmentId());
         break;
 
@@ -6905,7 +6913,7 @@ void HOptimizedGraphBuilder::HandleCompoundAssignment(Assignment* expr) {
 
     Push(BuildBinaryOperation(operation, left, right, PUSH_BEFORE_SIMULATE));
 
-    BuildStore(expr, prop, expr->id(),
+    BuildStore(expr, prop, expr->AssignmentSlot(), expr->id(),
                expr->AssignmentId(), expr->IsUninitialized());
   } else {
     return Bailout(kInvalidLhsInCompoundAssignment);
@@ -6956,8 +6964,7 @@ void HOptimizedGraphBuilder::VisitAssignment(Assignment* expr) {
       case VariableLocation::GLOBAL:
       case VariableLocation::UNALLOCATED:
         CHECK_ALIVE(VisitForValue(expr->value()));
-        HandleGlobalVariableAssignment(var,
-                                       Top(),
+        HandleGlobalVariableAssignment(var, Top(), expr->AssignmentSlot(),
                                        expr->AssignmentId());
         return ast_context()->ReturnValue(Pop());
 
@@ -7104,8 +7111,8 @@ HInstruction* HGraphBuilder::BuildLoadStringLength(HValue* string) {
 
 
 HInstruction* HOptimizedGraphBuilder::BuildNamedGeneric(
-    PropertyAccessType access_type, Expression* expr, HValue* object,
-    Handle<String> name, HValue* value, bool is_uninitialized) {
+    PropertyAccessType access_type, Expression* expr, FeedbackVectorICSlot slot,
+    HValue* object, Handle<Name> name, HValue* value, bool is_uninitialized) {
   if (is_uninitialized) {
     Add<HDeoptimize>(
         Deoptimizer::kInsufficientTypeFeedbackForGenericNamedAccess,
@@ -7114,7 +7121,6 @@ HInstruction* HOptimizedGraphBuilder::BuildNamedGeneric(
   if (access_type == LOAD) {
     Handle<TypeFeedbackVector> vector =
         handle(current_feedback_vector(), isolate());
-    FeedbackVectorICSlot slot = expr->AsProperty()->PropertyFeedbackSlot();
 
     if (!expr->AsProperty()->key()->IsPropertyName()) {
       // It's possible that a keyed load of a constant string was converted
@@ -7133,19 +7139,36 @@ HInstruction* HOptimizedGraphBuilder::BuildNamedGeneric(
     result->SetVectorAndSlot(vector, slot);
     return result;
   } else {
-    return New<HStoreNamedGeneric>(object, name, value,
-                                   function_language_mode(), PREMONOMORPHIC);
+    if (FLAG_vector_stores &&
+        current_feedback_vector()->GetKind(slot) == Code::KEYED_STORE_IC) {
+      // It's possible that a keyed store of a constant string was converted
+      // to a named store. Here, at the last minute, we need to make sure to
+      // use a generic Keyed Store if we are using the type vector, because
+      // it has to share information with full code.
+      HConstant* key = Add<HConstant>(name);
+      HStoreKeyedGeneric* result = New<HStoreKeyedGeneric>(
+          object, key, value, function_language_mode(), PREMONOMORPHIC);
+      Handle<TypeFeedbackVector> vector =
+          handle(current_feedback_vector(), isolate());
+      result->SetVectorAndSlot(vector, slot);
+      return result;
+    }
+
+    HStoreNamedGeneric* result = New<HStoreNamedGeneric>(
+        object, name, value, function_language_mode(), PREMONOMORPHIC);
+    if (FLAG_vector_stores) {
+      Handle<TypeFeedbackVector> vector =
+          handle(current_feedback_vector(), isolate());
+      result->SetVectorAndSlot(vector, slot);
+    }
+    return result;
   }
 }
 
 
-
 HInstruction* HOptimizedGraphBuilder::BuildKeyedGeneric(
-    PropertyAccessType access_type,
-    Expression* expr,
-    HValue* object,
-    HValue* key,
-    HValue* value) {
+    PropertyAccessType access_type, Expression* expr, FeedbackVectorICSlot slot,
+    HValue* object, HValue* key, HValue* value) {
   if (access_type == LOAD) {
     InlineCacheState initial_state = expr->AsProperty()->GetInlineCacheState();
     HLoadKeyedGeneric* result = New<HLoadKeyedGeneric>(
@@ -7156,13 +7179,18 @@ HInstruction* HOptimizedGraphBuilder::BuildKeyedGeneric(
       // We need to pass vector information.
       Handle<TypeFeedbackVector> vector =
           handle(current_feedback_vector(), isolate());
-      FeedbackVectorICSlot slot = expr->AsProperty()->PropertyFeedbackSlot();
       result->SetVectorAndSlot(vector, slot);
     }
     return result;
   } else {
-    return New<HStoreKeyedGeneric>(object, key, value, function_language_mode(),
-                                   PREMONOMORPHIC);
+    HStoreKeyedGeneric* result = New<HStoreKeyedGeneric>(
+        object, key, value, function_language_mode(), PREMONOMORPHIC);
+    if (FLAG_vector_stores) {
+      Handle<TypeFeedbackVector> vector =
+          handle(current_feedback_vector(), isolate());
+      result->SetVectorAndSlot(vector, slot);
+    }
+    return result;
   }
 }
 
@@ -7299,14 +7327,9 @@ HInstruction* HOptimizedGraphBuilder::TryBuildConsolidatedElementLoad(
 
 
 HValue* HOptimizedGraphBuilder::HandlePolymorphicElementAccess(
-    Expression* expr,
-    HValue* object,
-    HValue* key,
-    HValue* val,
-    SmallMapList* maps,
-    PropertyAccessType access_type,
-    KeyedAccessStoreMode store_mode,
-    bool* has_side_effects) {
+    Expression* expr, FeedbackVectorICSlot slot, HValue* object, HValue* key,
+    HValue* val, SmallMapList* maps, PropertyAccessType access_type,
+    KeyedAccessStoreMode store_mode, bool* has_side_effects) {
   *has_side_effects = false;
   BuildCheckHeapObject(object);
 
@@ -7334,8 +7357,8 @@ HValue* HOptimizedGraphBuilder::HandlePolymorphicElementAccess(
       possible_transitioned_maps.Add(map);
     }
     if (IsSloppyArgumentsElements(elements_kind)) {
-      HInstruction* result = BuildKeyedGeneric(access_type, expr, object, key,
-                                               val);
+      HInstruction* result =
+          BuildKeyedGeneric(access_type, expr, slot, object, key, val);
       *has_side_effects = result->HasObservableSideEffects();
       return AddInstruction(result);
     }
@@ -7371,8 +7394,8 @@ HValue* HOptimizedGraphBuilder::HandlePolymorphicElementAccess(
     Handle<Map> untransitionable_map = untransitionable_maps[0];
     HInstruction* instr = NULL;
     if (!CanInlineElementAccess(untransitionable_map)) {
-      instr = AddInstruction(BuildKeyedGeneric(access_type, expr, object, key,
-                                               val));
+      instr = AddInstruction(
+          BuildKeyedGeneric(access_type, expr, slot, object, key, val));
     } else {
       instr = BuildMonomorphicElementAccess(
           object, key, val, transition, untransitionable_map, access_type,
@@ -7396,8 +7419,8 @@ HValue* HOptimizedGraphBuilder::HandlePolymorphicElementAccess(
     set_current_block(this_map);
     HInstruction* access = NULL;
     if (!CanInlineElementAccess(map)) {
-      access = AddInstruction(BuildKeyedGeneric(access_type, expr, object, key,
-                                                val));
+      access = AddInstruction(
+          BuildKeyedGeneric(access_type, expr, slot, object, key, val));
     } else {
       DCHECK(IsFastElementsKind(elements_kind) ||
              IsFixedTypedArrayElementsKind(elements_kind));
@@ -7436,9 +7459,9 @@ HValue* HOptimizedGraphBuilder::HandlePolymorphicElementAccess(
 
 
 HValue* HOptimizedGraphBuilder::HandleKeyedElementAccess(
-    HValue* obj, HValue* key, HValue* val, Expression* expr, BailoutId ast_id,
-    BailoutId return_id, PropertyAccessType access_type,
-    bool* has_side_effects) {
+    HValue* obj, HValue* key, HValue* val, Expression* expr,
+    FeedbackVectorICSlot slot, BailoutId ast_id, BailoutId return_id,
+    PropertyAccessType access_type, bool* has_side_effects) {
   if (key->ActualValue()->IsConstant()) {
     Handle<Object> constant =
         HConstant::cast(key->ActualValue())->handle(isolate());
@@ -7450,7 +7473,7 @@ HValue* HOptimizedGraphBuilder::HandleKeyedElementAccess(
             Handle<String>::cast(constant));
       }
       HValue* access =
-          BuildNamedAccess(access_type, ast_id, return_id, expr, obj,
+          BuildNamedAccess(access_type, ast_id, return_id, expr, slot, obj,
                            Handle<String>::cast(constant), val, false);
       if (access == NULL || access->IsPhi() ||
           HInstruction::cast(access)->IsLinked()) {
@@ -7509,15 +7532,15 @@ HValue* HOptimizedGraphBuilder::HandleKeyedElementAccess(
   if (monomorphic) {
     Handle<Map> map = maps->first();
     if (!CanInlineElementAccess(map)) {
-      instr = AddInstruction(BuildKeyedGeneric(access_type, expr, obj, key,
-                                               val));
+      instr = AddInstruction(
+          BuildKeyedGeneric(access_type, expr, slot, obj, key, val));
     } else {
       BuildCheckHeapObject(obj);
       instr = BuildMonomorphicElementAccess(
           obj, key, val, NULL, map, access_type, expr->GetStoreMode());
     }
   } else if (!force_generic && (maps != NULL && !maps->is_empty())) {
-    return HandlePolymorphicElementAccess(expr, obj, key, val, maps,
+    return HandlePolymorphicElementAccess(expr, slot, obj, key, val, maps,
                                           access_type, expr->GetStoreMode(),
                                           has_side_effects);
   } else {
@@ -7533,7 +7556,8 @@ HValue* HOptimizedGraphBuilder::HandleKeyedElementAccess(
                          Deoptimizer::SOFT);
       }
     }
-    instr = AddInstruction(BuildKeyedGeneric(access_type, expr, obj, key, val));
+    instr = AddInstruction(
+        BuildKeyedGeneric(access_type, expr, slot, obj, key, val));
   }
   *has_side_effects = instr->HasObservableSideEffects();
   return instr;
@@ -7621,8 +7645,8 @@ bool HOptimizedGraphBuilder::TryArgumentsAccess(Property* expr) {
 
 HValue* HOptimizedGraphBuilder::BuildNamedAccess(
     PropertyAccessType access, BailoutId ast_id, BailoutId return_id,
-    Expression* expr, HValue* object, Handle<String> name, HValue* value,
-    bool is_uninitialized) {
+    Expression* expr, FeedbackVectorICSlot slot, HValue* object,
+    Handle<String> name, HValue* value, bool is_uninitialized) {
   SmallMapList* maps;
   ComputeReceiverTypes(expr, object, &maps, zone());
   DCHECK(maps != NULL);
@@ -7630,8 +7654,8 @@ HValue* HOptimizedGraphBuilder::BuildNamedAccess(
   if (maps->length() > 0) {
     PropertyAccessInfo info(this, access, maps->first(), name);
     if (!info.CanAccessAsMonomorphic(maps)) {
-      HandlePolymorphicNamedFieldAccess(access, expr, ast_id, return_id, object,
-                                        value, maps, name);
+      HandlePolymorphicNamedFieldAccess(access, expr, slot, ast_id, return_id,
+                                        object, value, maps, name);
       return NULL;
     }
 
@@ -7649,7 +7673,8 @@ HValue* HOptimizedGraphBuilder::BuildNamedAccess(
         &info, object, checked_object, value, ast_id, return_id);
   }
 
-  return BuildNamedGeneric(access, expr, object, name, value, is_uninitialized);
+  return BuildNamedGeneric(access, expr, slot, object, name, value,
+                           is_uninitialized);
 }
 
 
@@ -7677,8 +7702,9 @@ void HOptimizedGraphBuilder::BuildLoad(Property* expr,
     Handle<String> name = expr->key()->AsLiteral()->AsPropertyName();
     HValue* object = Pop();
 
-    HValue* value = BuildNamedAccess(LOAD, ast_id, expr->LoadId(), expr, object,
-                                     name, NULL, expr->IsUninitialized());
+    HValue* value = BuildNamedAccess(LOAD, ast_id, expr->LoadId(), expr,
+                                     expr->PropertyFeedbackSlot(), object, name,
+                                     NULL, expr->IsUninitialized());
     if (value == NULL) return;
     if (value->IsPhi()) return ast_context()->ReturnValue(value);
     instr = HInstruction::cast(value);
@@ -7690,7 +7716,8 @@ void HOptimizedGraphBuilder::BuildLoad(Property* expr,
 
     bool has_side_effects = false;
     HValue* load = HandleKeyedElementAccess(
-        obj, key, NULL, expr, ast_id, expr->LoadId(), LOAD, &has_side_effects);
+        obj, key, NULL, expr, expr->PropertyFeedbackSlot(), ast_id,
+        expr->LoadId(), LOAD, &has_side_effects);
     if (has_side_effects) {
       if (ast_context()->IsEffect()) {
         Add<HSimulate>(ast_id, REMOVABLE_SIMULATE);
@@ -7973,8 +8000,9 @@ void HOptimizedGraphBuilder::HandlePolymorphicCallNamed(Call* expr,
     FinishExitWithHardDeoptimization(Deoptimizer::kUnknownMapInPolymorphicCall);
   } else {
     Property* prop = expr->expression()->AsProperty();
-    HInstruction* function = BuildNamedGeneric(
-        LOAD, prop, receiver, name, NULL, prop->IsUninitialized());
+    HInstruction* function =
+        BuildNamedGeneric(LOAD, prop, prop->PropertyFeedbackSlot(), receiver,
+                          name, NULL, prop->IsUninitialized());
     AddInstruction(function);
     Push(function);
     AddSimulate(prop->LoadId(), REMOVABLE_SIMULATE);
@@ -10431,18 +10459,15 @@ HInstruction* HOptimizedGraphBuilder::BuildIncrement(
 }
 
 
-void HOptimizedGraphBuilder::BuildStoreForEffect(Expression* expr,
-                                                 Property* prop,
-                                                 BailoutId ast_id,
-                                                 BailoutId return_id,
-                                                 HValue* object,
-                                                 HValue* key,
-                                                 HValue* value) {
+void HOptimizedGraphBuilder::BuildStoreForEffect(
+    Expression* expr, Property* prop, FeedbackVectorICSlot slot,
+    BailoutId ast_id, BailoutId return_id, HValue* object, HValue* key,
+    HValue* value) {
   EffectContext for_effect(this);
   Push(object);
   if (key != NULL) Push(key);
   Push(value);
-  BuildStore(expr, prop, ast_id, return_id);
+  BuildStore(expr, prop, slot, ast_id, return_id);
 }
 
 
@@ -10485,8 +10510,7 @@ void HOptimizedGraphBuilder::VisitCountOperation(CountOperation* expr) {
     switch (var->location()) {
       case VariableLocation::GLOBAL:
       case VariableLocation::UNALLOCATED:
-        HandleGlobalVariableAssignment(var,
-                                       after,
+        HandleGlobalVariableAssignment(var, after, expr->CountSlot(),
                                        expr->AssignmentId());
         break;
 
@@ -10552,13 +10576,14 @@ void HOptimizedGraphBuilder::VisitCountOperation(CountOperation* expr) {
     // Drop object and key to push it again in the effect context below.
     Drop(key == NULL ? 1 : 2);
     environment()->SetExpressionStackAt(0, input);
-    CHECK_ALIVE(BuildStoreForEffect(
-        expr, prop, expr->id(), expr->AssignmentId(), object, key, after));
+    CHECK_ALIVE(BuildStoreForEffect(expr, prop, expr->CountSlot(), expr->id(),
+                                    expr->AssignmentId(), object, key, after));
     return ast_context()->ReturnValue(Pop());
   }
 
   environment()->SetExpressionStackAt(0, after);
-  return BuildStore(expr, prop, expr->id(), expr->AssignmentId());
+  return BuildStore(expr, prop, expr->CountSlot(), expr->id(),
+                    expr->AssignmentId());
 }