[cleanup] Use IsNull, IsUndefined and IsNullOrUndefined in CSA

Bug: v8:6921
Change-Id: Icbbb7c08b9ff9f20339988770d88d96653a9ddef
Reviewed-on: https://chromium-review.googlesource.com/718656
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#48890}

src/builtins/builtins-array-gen.cc

@@ -363,10 +363,7 @@ class ArrayBuiltinCodeStubAssembler : public CodeStubAssembler {
     // TODO(danno): Seriously? Do we really need to throw the exact error
     // message on null and undefined so that the webkit tests pass?
     Label throw_null_undefined_exception(this, Label::kDeferred);
-    GotoIf(WordEqual(receiver(), NullConstant()),
-           &throw_null_undefined_exception);
-    GotoIf(WordEqual(receiver(), UndefinedConstant()),
-           &throw_null_undefined_exception);
+    GotoIf(IsNullOrUndefined(receiver()), &throw_null_undefined_exception);
 
     // By the book: taken directly from the ECMAScript 2015 specification
 
@@ -859,8 +856,7 @@ class ArrayBuiltinCodeStubAssembler : public CodeStubAssembler {
 TF_BUILTIN(FastArrayPop, CodeStubAssembler) {
   Node* argc = Parameter(BuiltinDescriptor::kArgumentsCount);
   Node* context = Parameter(BuiltinDescriptor::kContext);
-  CSA_ASSERT(this, WordEqual(Parameter(BuiltinDescriptor::kNewTarget),
-                             UndefinedConstant()));
+  CSA_ASSERT(this, IsUndefined(Parameter(BuiltinDescriptor::kNewTarget)));
 
   CodeStubArguments args(this, ChangeInt32ToIntPtr(argc));
   Node* receiver = args.GetReceiver();
@@ -969,8 +965,7 @@ TF_BUILTIN(FastArrayPush, CodeStubAssembler) {
   // arguments are reordered.
   Node* argc = Parameter(BuiltinDescriptor::kArgumentsCount);
   Node* context = Parameter(BuiltinDescriptor::kContext);
-  CSA_ASSERT(this, WordEqual(Parameter(BuiltinDescriptor::kNewTarget),
-                             UndefinedConstant()));
+  CSA_ASSERT(this, IsUndefined(Parameter(BuiltinDescriptor::kNewTarget)));
 
   CodeStubArguments args(this, ChangeInt32ToIntPtr(argc));
   Node* receiver = args.GetReceiver();
@@ -1401,8 +1396,7 @@ TF_BUILTIN(FastArraySlice, FastArraySliceCodeStubAssembler) {
 TF_BUILTIN(FastArrayShift, CodeStubAssembler) {
   Node* argc = Parameter(BuiltinDescriptor::kArgumentsCount);
   Node* context = Parameter(BuiltinDescriptor::kContext);
-  CSA_ASSERT(this, WordEqual(Parameter(BuiltinDescriptor::kNewTarget),
-                             UndefinedConstant()));
+  CSA_ASSERT(this, IsUndefined(Parameter(BuiltinDescriptor::kNewTarget)));
 
   CodeStubArguments args(this, ChangeInt32ToIntPtr(argc));
   Node* receiver = args.GetReceiver();
@@ -2730,7 +2724,7 @@ TF_BUILTIN(ArrayIteratorPrototypeNext, CodeStubAssembler) {
     Label if_istypedarray(this), if_isgeneric(this);
 
     // If a is undefined, return CreateIterResultObject(undefined, true)
-    GotoIf(WordEqual(array, UndefinedConstant()), &allocate_iterator_result);
+    GotoIf(IsUndefined(array), &allocate_iterator_result);
 
     Node* array_type = LoadInstanceType(array);
     Branch(InstanceTypeEqual(array_type, JS_TYPED_ARRAY_TYPE), &if_istypedarray,

src/builtins/builtins-collections-gen.cc

@@ -1744,7 +1744,7 @@ TF_BUILTIN(WeakMapLookupHashIndex, CollectionsBuiltinsAssembler) {
         IntPtrAdd(index, IntPtrConstant(WeakHashTable::kElementsStartIndex));
 
     Node* current = LoadFixedArrayElement(table, index);
-    GotoIf(WordEqual(current, UndefinedConstant()), &if_not_found);
+    GotoIf(IsUndefined(current), &if_not_found);
     GotoIf(WordEqual(current, key), &if_found);
 
     // See HashTable::NextProbe().

src/builtins/builtins-conversion-gen.cc

@@ -33,9 +33,7 @@ void ConversionBuiltinsAssembler::Generate_NonPrimitiveToPrimitive(
 
   // Check if {exotic_to_prim} is neither null nor undefined.
   Label ordinary_to_primitive(this);
-  GotoIf(WordEqual(exotic_to_prim, NullConstant()), &ordinary_to_primitive);
-  GotoIf(WordEqual(exotic_to_prim, UndefinedConstant()),
-         &ordinary_to_primitive);
+  GotoIf(IsNullOrUndefined(exotic_to_prim), &ordinary_to_primitive);
   {
     // Invoke the {exotic_to_prim} method on the {input} with a string
     // representation of the {hint}.

src/builtins/builtins-number-gen.cc

@@ -283,7 +283,7 @@ TF_BUILTIN(NumberParseInt, CodeStubAssembler) {
 
   // Check if {radix} is treated as 10 (i.e. undefined, 0 or 10).
   Label if_radix10(this), if_generic(this, Label::kDeferred);
-  GotoIf(WordEqual(radix, UndefinedConstant()), &if_radix10);
+  GotoIf(IsUndefined(radix), &if_radix10);
   GotoIf(WordEqual(radix, SmiConstant(10)), &if_radix10);
   GotoIf(WordEqual(radix, SmiConstant(0)), &if_radix10);
   Goto(&if_generic);

src/builtins/builtins-object-gen.cc

@@ -577,7 +577,7 @@ TF_BUILTIN(ObjectCreate, ObjectBuiltinsAssembler) {
       no_properties(this);
   {
     Comment("Argument 1 check: prototype");
-    GotoIf(WordEqual(prototype, NullConstant()), &prototype_valid);
+    GotoIf(IsNull(prototype), &prototype_valid);
     BranchIfJSReceiver(prototype, &prototype_valid, &call_runtime);
   }
 
@@ -587,7 +587,7 @@ TF_BUILTIN(ObjectCreate, ObjectBuiltinsAssembler) {
     // Check that we have a simple object
     GotoIf(TaggedIsSmi(properties), &call_runtime);
     // Undefined implies no properties.
-    GotoIf(WordEqual(properties, UndefinedConstant()), &no_properties);
+    GotoIf(IsUndefined(properties), &no_properties);
     Node* properties_map = LoadMap(properties);
     GotoIf(IsSpecialReceiverMap(properties_map), &call_runtime);
     // Stay on the fast path only if there are no elements.
@@ -608,7 +608,7 @@ TF_BUILTIN(ObjectCreate, ObjectBuiltinsAssembler) {
     VARIABLE(properties, MachineRepresentation::kTagged);
     Label non_null_proto(this), instantiate_map(this), good(this);
 
-    Branch(WordEqual(prototype, NullConstant()), &good, &non_null_proto);
+    Branch(IsNull(prototype), &good, &non_null_proto);
 
     BIND(&good);
     {
@@ -634,7 +634,7 @@ TF_BUILTIN(ObjectCreate, ObjectBuiltinsAssembler) {
       Comment("Load ObjectCreateMap from PrototypeInfo");
       Node* weak_cell =
           LoadObjectField(prototype_info, PrototypeInfo::kObjectCreateMap);
-      GotoIf(WordEqual(weak_cell, UndefinedConstant()), &call_runtime);
+      GotoIf(IsUndefined(weak_cell), &call_runtime);
       map.Bind(LoadWeakCellValue(weak_cell, &call_runtime));
       Goto(&instantiate_map);
     }
@@ -769,8 +769,7 @@ TF_BUILTIN(CreateGeneratorObject, ObjectBuiltinsAssembler) {
 TF_BUILTIN(ObjectGetOwnPropertyDescriptor, ObjectBuiltinsAssembler) {
   Node* argc = Parameter(BuiltinDescriptor::kArgumentsCount);
   Node* context = Parameter(BuiltinDescriptor::kContext);
-  CSA_ASSERT(this, WordEqual(Parameter(BuiltinDescriptor::kNewTarget),
-                             UndefinedConstant()));
+  CSA_ASSERT(this, IsUndefined(Parameter(BuiltinDescriptor::kNewTarget)));
 
   CodeStubArguments args(this, ChangeInt32ToIntPtr(argc));
   Node* object = args.GetOptionalArgumentValue(0);

src/builtins/builtins-promise-gen.cc

@@ -302,8 +302,7 @@ Node* PromiseBuiltinsAssembler::SpeciesConstructor(Node* context, Node* object,
       GetProperty(context, constructor, isolate->factory()->species_symbol());
 
   // 6. If S is either undefined or null, return defaultConstructor.
-  GotoIf(IsUndefined(species), &out);
-  GotoIf(WordEqual(species, NullConstant()), &out);
+  GotoIf(IsNullOrUndefined(species), &out);
 
   // 7. If IsConstructor(S) is true, return S.
   Label throw_error(this);
@@ -1456,13 +1455,11 @@ TF_BUILTIN(PromiseGetCapabilitiesExecutor, PromiseBuiltinsAssembler) {
   Node* const capability = LoadContextElement(context, kCapabilitySlot);
 
   Label if_alreadyinvoked(this, Label::kDeferred);
-  GotoIf(WordNotEqual(
-             LoadObjectField(capability, PromiseCapability::kResolveOffset),
-             UndefinedConstant()),
+  GotoIfNot(IsUndefined(
+                LoadObjectField(capability, PromiseCapability::kResolveOffset)),
             &if_alreadyinvoked);
-  GotoIf(WordNotEqual(
-             LoadObjectField(capability, PromiseCapability::kRejectOffset),
-             UndefinedConstant()),
+  GotoIfNot(IsUndefined(
+                LoadObjectField(capability, PromiseCapability::kRejectOffset)),
             &if_alreadyinvoked);
 
   StoreObjectField(capability, PromiseCapability::kResolveOffset, resolve);

src/builtins/builtins-regexp-gen.cc

@@ -654,7 +654,6 @@ Node* RegExpBuiltinsAssembler::RegExpExecInternal(Node* const context,
 Node* RegExpBuiltinsAssembler::RegExpPrototypeExecBodyWithoutResult(
     Node* const context, Node* const regexp, Node* const string,
     Label* if_didnotmatch, const bool is_fastpath) {
-  Node* const null = NullConstant();
   Node* const int_zero = IntPtrConstant(0);
   Node* const smi_zero = SmiConstant(0);
 
@@ -722,7 +721,7 @@ Node* RegExpBuiltinsAssembler::RegExpPrototypeExecBodyWithoutResult(
       BIND(&if_isoob);
       {
         StoreLastIndex(context, regexp, smi_zero, is_fastpath);
-        var_result.Bind(null);
+        var_result.Bind(NullConstant());
         Goto(if_didnotmatch);
       }
     }
@@ -750,7 +749,7 @@ Node* RegExpBuiltinsAssembler::RegExpPrototypeExecBodyWithoutResult(
 
     // {match_indices} is either null or the RegExpMatchInfo array.
     // Return early if exec failed, possibly updating last index.
-    GotoIfNot(WordEqual(match_indices, null), &successful_match);
+    GotoIfNot(IsNull(match_indices), &successful_match);
 
     GotoIfNot(should_update_last_index, if_didnotmatch);
 
@@ -780,8 +779,6 @@ Node* RegExpBuiltinsAssembler::RegExpPrototypeExecBody(Node* const context,
                                                        Node* const regexp,
                                                        Node* const string,
                                                        const bool is_fastpath) {
-  Node* const null = NullConstant();
-
   VARIABLE(var_result, MachineRepresentation::kTagged);
 
   Label if_didnotmatch(this), out(this);
@@ -799,7 +796,7 @@ Node* RegExpBuiltinsAssembler::RegExpPrototypeExecBody(Node* const context,
 
   BIND(&if_didnotmatch);
   {
-    var_result.Bind(null);
+    var_result.Bind(NullConstant());
     Goto(&out);
   }
 
@@ -1704,7 +1701,7 @@ Node* RegExpBuiltinsAssembler::RegExpExec(Node* context, Node* regexp,
     Node* const result = CallJS(call_callable, context, exec, regexp, string);
 
     var_result.Bind(result);
-    GotoIf(WordEqual(result, NullConstant()), &out);
+    GotoIf(IsNull(result), &out);
 
     ThrowIfNotJSReceiver(context, result,
                          MessageTemplate::kInvalidRegExpExecResult, "");
@@ -1763,8 +1760,7 @@ TF_BUILTIN(RegExpPrototypeTest, RegExpBuiltinsAssembler) {
     Node* const match_indices = RegExpExec(context, receiver, string);
 
     // Return true iff exec matched successfully.
-    Node* const result =
-        SelectBooleanConstant(WordNotEqual(match_indices, NullConstant()));
+    Node* const result = SelectBooleanConstant(IsNotNull(match_indices));
     Return(result);
   }
 }
@@ -1983,7 +1979,6 @@ void RegExpBuiltinsAssembler::RegExpPrototypeMatchBody(Node* const context,
   CSA_ASSERT(this, IsString(string));
   if (is_fastpath) CSA_ASSERT(this, IsFastRegExp(context, regexp));
 
-  Node* const null = NullConstant();
   Node* const int_zero = IntPtrConstant(0);
   Node* const smi_zero = SmiConstant(0);
 
@@ -2045,7 +2040,7 @@ void RegExpBuiltinsAssembler::RegExpPrototypeMatchBody(Node* const context,
         Node* const result = RegExpExec(context, regexp, string);
 
         Label load_match(this);
-        Branch(WordEqual(result, null), &if_didnotmatch, &load_match);
+        Branch(IsNull(result), &if_didnotmatch, &load_match);
 
         BIND(&load_match);
         {
@@ -2078,7 +2073,7 @@ void RegExpBuiltinsAssembler::RegExpPrototypeMatchBody(Node* const context,
       {
         // Return null if there were no matches, otherwise just exit the loop.
         GotoIfNot(IntPtrEqual(array.length(), int_zero), &out);
-        Return(null);
+        Return(NullConstant());
       }
 
       BIND(&if_didmatch);
@@ -2244,7 +2239,7 @@ void RegExpBuiltinsAssembler::RegExpPrototypeSearchBodySlow(
   // Return -1 if no match was found.
   {
     Label next(this);
-    GotoIfNot(WordEqual(exec_result, NullConstant()), &next);
+    GotoIfNot(IsNull(exec_result), &next);
     Return(SmiConstant(-1));
     BIND(&next);
   }
@@ -2319,7 +2314,6 @@ void RegExpBuiltinsAssembler::RegExpPrototypeSplitBody(Node* const context,
   CSA_ASSERT(this, TaggedIsSmi(limit));
   CSA_ASSERT(this, IsString(string));
 
-  Node* const null = NullConstant();
   Node* const smi_zero = SmiConstant(0);
   Node* const int_zero = IntPtrConstant(0);
   Node* const int_limit = SmiUntag(limit);
@@ -2357,7 +2351,7 @@ void RegExpBuiltinsAssembler::RegExpPrototypeSplitBody(Node* const context,
                                                      smi_zero, last_match_info);
 
       Label return_singleton_array(this);
-      Branch(WordEqual(match_indices, null), &return_singleton_array,
+      Branch(IsNull(match_indices), &return_singleton_array,
              &return_empty_array);
 
       BIND(&return_singleton_array);
@@ -2421,7 +2415,7 @@ void RegExpBuiltinsAssembler::RegExpPrototypeSplitBody(Node* const context,
     // We're done if no match was found.
     {
       Label next(this);
-      Branch(WordEqual(match_indices, null), &push_suffix_and_out, &next);
+      Branch(IsNull(match_indices), &push_suffix_and_out, &next);
       BIND(&next);
     }
 
@@ -2675,7 +2669,6 @@ Node* RegExpBuiltinsAssembler::ReplaceGlobalCallableFastPath(
 
   Isolate* const isolate = this->isolate();
 
-  Node* const null = NullConstant();
   Node* const undefined = UndefinedConstant();
   Node* const int_zero = IntPtrConstant(0);
   Node* const int_one = IntPtrConstant(1);
@@ -2714,7 +2707,7 @@ Node* RegExpBuiltinsAssembler::ReplaceGlobalCallableFastPath(
 
   // If no matches, return the subject string.
   var_result.Bind(string);
-  GotoIf(WordEqual(res, null), &out);
+  GotoIf(IsNull(res), &out);
 
   // Reload last match info since it might have changed.
   last_match_info =
@@ -3109,7 +3102,6 @@ TF_BUILTIN(RegExpInternalMatch, RegExpBuiltinsAssembler) {
   Node* const string = Parameter(Descriptor::kString);
   Node* const context = Parameter(Descriptor::kContext);
 
-  Node* const null = NullConstant();
   Node* const smi_zero = SmiConstant(0);
 
   CSA_ASSERT(this, IsJSRegExp(regexp));
@@ -3122,6 +3114,7 @@ TF_BUILTIN(RegExpInternalMatch, RegExpBuiltinsAssembler) {
   Node* const match_indices = RegExpExecInternal(context, regexp, string,
                                                  smi_zero, internal_match_info);
 
+  Node* const null = NullConstant();
   Label if_matched(this), if_didnotmatch(this);
   Branch(WordEqual(match_indices, null), &if_didnotmatch, &if_matched);
 

src/builtins/builtins-string-gen.cc

@@ -1033,10 +1033,6 @@ void StringIncludesIndexOfAssembler::Generate(SearchVariant variant) {
   }
 }
 
-compiler::Node* StringBuiltinsAssembler::IsNullOrUndefined(Node* const value) {
-  return Word32Or(IsUndefined(value), IsNull(value));
-}
-
 void StringBuiltinsAssembler::RequireObjectCoercible(Node* const context,
                                                      Node* const value,
                                                      const char* method_name) {
@@ -1703,7 +1699,7 @@ TF_BUILTIN(StringPrototypeSlice, StringBuiltinsAssembler) {
 
   // 5. If end is undefined, let intEnd be len;
   var_end.Bind(length);
-  GotoIf(WordEqual(end, UndefinedConstant()), &out);
+  GotoIf(IsUndefined(end), &out);
 
   // else let intEnd be ? ToInteger(end).
   Node* const end_int =
@@ -1889,8 +1885,7 @@ TF_BUILTIN(StringPrototypeSubstr, StringBuiltinsAssembler) {
   // Default to {string_length} if {length} is undefined.
   {
     Label if_isundefined(this, Label::kDeferred), if_isnotundefined(this);
-    Branch(WordEqual(length, UndefinedConstant()), &if_isundefined,
-           &if_isnotundefined);
+    Branch(IsUndefined(length), &if_isundefined, &if_isnotundefined);
 
     BIND(&if_isundefined);
     var_length.Bind(string_length);
@@ -2037,7 +2032,7 @@ TF_BUILTIN(StringPrototypeSubstring, StringBuiltinsAssembler) {
   // Conversion and bounds-checks for {end}.
   {
     var_end.Bind(length);
-    GotoIf(WordEqual(end, UndefinedConstant()), &out);
+    GotoIf(IsUndefined(end), &out);
 
     var_end.Bind(ToSmiBetweenZeroAnd(context, end, length));
 

src/builtins/builtins-string-gen.h

@@ -63,7 +63,6 @@ class StringBuiltinsAssembler : public CodeStubAssembler {
 
   Node* IndexOfDollarChar(Node* const context, Node* const string);
 
-  Node* IsNullOrUndefined(Node* const value);
   void RequireObjectCoercible(Node* const context, Node* const value,
                               const char* method_name);
 

src/code-stub-assembler.cc

@@ -803,7 +803,7 @@ void CodeStubAssembler::BranchIfPrototypesHaveNoElements(
   {
     Node* map = var_map.value();
     Node* prototype = LoadMapPrototype(map);
-    GotoIf(WordEqual(prototype, NullConstant()), definitely_no_elements);
+    GotoIf(IsNull(prototype), definitely_no_elements);
     Node* prototype_map = LoadMap(prototype);
     // Pessimistically assume elements if a Proxy, Special API Object,
     // or JSValue wrapper is found on the prototype chain. After this
@@ -3686,23 +3686,11 @@ Node* CodeStubAssembler::ToThisString(Node* context, Node* value,
     BIND(&if_valueisnotstring);
     {
       // Check if the {value} is null.
-      Label if_valueisnullorundefined(this, Label::kDeferred),
-          if_valueisnotnullorundefined(this, Label::kDeferred),
-          if_valueisnotnull(this, Label::kDeferred);
-      Branch(WordEqual(value, NullConstant()), &if_valueisnullorundefined,
-             &if_valueisnotnull);
-      BIND(&if_valueisnotnull);
-      {
-        // Check if the {value} is undefined.
-        Branch(WordEqual(value, UndefinedConstant()),
-               &if_valueisnullorundefined, &if_valueisnotnullorundefined);
-        BIND(&if_valueisnotnullorundefined);
-        {
+      Label if_valueisnullorundefined(this, Label::kDeferred);
+      GotoIf(IsNullOrUndefined(value), &if_valueisnullorundefined);
       // Convert the {value} to a String.
       var_value.Bind(CallBuiltin(Builtins::kToString, context, value));
       Goto(&if_valueisstring);
-        }
-      }
 
       BIND(&if_valueisnullorundefined);
       {
@@ -4100,6 +4088,10 @@ Node* CodeStubAssembler::IsNullOrJSReceiver(Node* object) {
   return Word32Or(IsJSReceiver(object), IsNull(object));
 }
 
+Node* CodeStubAssembler::IsNullOrUndefined(Node* const value) {
+  return Word32Or(IsUndefined(value), IsNull(value));
+}
+
 Node* CodeStubAssembler::IsJSGlobalProxyInstanceType(Node* instance_type) {
   return InstanceTypeEqual(instance_type, JS_GLOBAL_PROXY_TYPE);
 }
@@ -4489,8 +4481,7 @@ Node* CodeStubAssembler::StringFromCharCode(Node* code) {
     Label if_entryisundefined(this, Label::kDeferred),
         if_entryisnotundefined(this);
     Node* entry = LoadFixedArrayElement(cache, code_index);
-    Branch(WordEqual(entry, UndefinedConstant()), &if_entryisundefined,
-           &if_entryisnotundefined);
+    Branch(IsUndefined(entry), &if_entryisundefined, &if_entryisnotundefined);
 
     BIND(&if_entryisundefined);
     {
@@ -7024,9 +7015,7 @@ void CodeStubAssembler::TryPrototypeChainLookup(
 
       Node* proto = LoadMapPrototype(holder_map);
 
-      Label if_not_null(this);
-      Branch(WordEqual(proto, NullConstant()), if_end, &if_not_null);
-      BIND(&if_not_null);
+      GotoIf(IsNull(proto), if_end);
 
       Node* map = LoadMap(proto);
       Node* instance_type = LoadMapInstanceType(map);
@@ -7059,9 +7048,7 @@ void CodeStubAssembler::TryPrototypeChainLookup(
 
       Node* proto = LoadMapPrototype(var_holder_map.value());
 
-      Label if_not_null(this);
-      Branch(WordEqual(proto, NullConstant()), if_end, &if_not_null);
-      BIND(&if_not_null);
+      GotoIf(IsNull(proto), if_end);
 
       Node* map = LoadMap(proto);
       Node* instance_type = LoadMapInstanceType(map);

src/code-stub-assembler.h

@@ -1056,6 +1056,7 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
   Node* IsJSReceiverMap(Node* map);
   Node* IsJSReceiver(Node* object);
   Node* IsNullOrJSReceiver(Node* object);
+  Node* IsNullOrUndefined(Node* object);
   Node* IsJSRegExp(Node* object);
   Node* IsJSTypedArray(Node* object);
   Node* IsJSValueInstanceType(Node* instance_type);

src/ic/accessor-assembler.cc

@@ -509,8 +509,7 @@ void AccessorAssembler::HandleLoadICProtoHandlerCase(
   {
     Label load_from_cached_holder(this), done(this);
 
-    Branch(WordEqual(maybe_holder_cell, NullConstant()), &done,
-           &load_from_cached_holder);
+    Branch(IsNull(maybe_holder_cell), &done, &load_from_cached_holder);
 
     BIND(&load_from_cached_holder);
     {
@@ -593,7 +592,7 @@ Node* AccessorAssembler::EmitLoadICProtoArrayCheck(const LoadICParameters* p,
 
   VARIABLE(var_holder, MachineRepresentation::kTagged, p->receiver);
   Label done(this);
-  GotoIf(WordEqual(maybe_holder_cell, NullConstant()), &done);
+  GotoIf(IsNull(maybe_holder_cell), &done);
 
   {
     // For regular holders, having passed the receiver map check and the

src/ic/keyed-store-generic.cc

@@ -108,7 +108,7 @@ void KeyedStoreGenericAssembler::BranchIfPrototypesHaveNonFastElements(
   {
     Node* map = var_map.value();
     Node* prototype = LoadMapPrototype(map);
-    GotoIf(WordEqual(prototype, NullConstant()), only_fast_elements);
+    GotoIf(IsNull(prototype), only_fast_elements);
     Node* prototype_map = LoadMap(prototype);
     var_map.Bind(prototype_map);
     Node* instance_type = LoadMapInstanceType(prototype_map);
@@ -596,6 +596,7 @@ void KeyedStoreGenericAssembler::LookupPropertyOnPrototypeChain(
     // Bailout if it can be an integer indexed exotic case.
     GotoIf(InstanceTypeEqual(instance_type, JS_TYPED_ARRAY_TYPE), bailout);
     Node* proto = LoadMapPrototype(holder_map);
+    GotoIf(IsNull(proto), &ok_to_write);
     var_holder.Bind(proto);
     var_holder_map.Bind(LoadMap(proto));
     Goto(&loop);

src/interpreter/interpreter-generator.cc

@@ -2066,7 +2066,7 @@ IGNITION_HANDLER(TestTypeOf, InterpreterAssembler) {
     GotoIf(TaggedIsSmi(object), &if_false);
 
     // If the object is null then return true.
-    GotoIf(WordEqual(object, NullConstant()), &if_true);
+    GotoIf(IsNull(object), &if_true);
 
     // Check if the object is a receiver type and is not undefined or callable.
     Node* map = LoadMap(object);