[csa][cleanup] Remove unneeded Unhcecked casts from T to the same T

For example, there is no need to do UncheckedCast<Object>(obj), if obj
is already of type Object.

Bug: v8:6949
Change-Id: I44278a023cb8741ead7b554569c66f412f01ffee
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2737294Reviewed-by: Mythri Alle <mythria@chromium.org>
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73210}

src/builtins/builtins-collections-gen.cc

@@ -910,7 +910,7 @@ TNode<IntPtrT> CollectionsBuiltinsAssembler::GetHash(
 
   BIND(&if_receiver);
   {
-    var_hash = LoadJSReceiverIdentityHash(key);
+    var_hash = LoadJSReceiverIdentityHash(CAST(key));
     Goto(&done);
   }
 
@@ -2722,7 +2722,7 @@ TF_BUILTIN(WeakMapLookupHashIndex, WeakCollectionsBuiltinsAssembler) {
 
   GotoIfNotJSReceiver(key, &if_not_found);
 
-  TNode<IntPtrT> hash = LoadJSReceiverIdentityHash(key, &if_not_found);
+  TNode<IntPtrT> hash = LoadJSReceiverIdentityHash(CAST(key), &if_not_found);
   TNode<IntPtrT> capacity = LoadTableCapacity(table);
   TNode<IntPtrT> key_index =
       FindKeyIndexForKey(table, key, hash, EntryMask(capacity), &if_not_found);
@@ -2787,7 +2787,7 @@ TF_BUILTIN(WeakCollectionDelete, WeakCollectionsBuiltinsAssembler) {
 
   GotoIfNotJSReceiver(key, &if_not_found);
 
-  TNode<IntPtrT> hash = LoadJSReceiverIdentityHash(key, &if_not_found);
+  TNode<IntPtrT> hash = LoadJSReceiverIdentityHash(CAST(key), &if_not_found);
   TNode<EphemeronHashTable> table = LoadTable(collection);
   TNode<IntPtrT> capacity = LoadTableCapacity(table);
   TNode<IntPtrT> key_index =

src/builtins/builtins-iterator-gen.cc

@@ -54,8 +54,7 @@ IteratorRecord IteratorBuiltinsAssembler::GetIterator(TNode<Context> context,
     BIND(&get_next);
     TNode<Object> next =
         GetProperty(context, iterator, factory()->next_string());
-    return IteratorRecord{TNode<JSReceiver>::UncheckedCast(iterator),
-                          TNode<Object>::UncheckedCast(next)};
+    return IteratorRecord{TNode<JSReceiver>::UncheckedCast(iterator), next};
   }
 }
 

src/builtins/builtins-object-gen.cc

@@ -320,7 +320,7 @@ TNode<JSArray> ObjectEntriesValuesBuiltinsAssembler::FastGetOwnValuesOrEntries(
             IntPtrConstant(2));
         StoreFixedArrayElement(CAST(elements), 0, next_key, SKIP_WRITE_BARRIER);
         StoreFixedArrayElement(CAST(elements), 1, value, SKIP_WRITE_BARRIER);
-        value = TNode<JSArray>::UncheckedCast(array);
+        value = array;
       }
 
       StoreFixedArrayElement(values_or_entries, var_result_index.value(),
@@ -350,7 +350,7 @@ ObjectEntriesValuesBuiltinsAssembler::FinalizeValuesOrEntriesJSArray(
 
   GotoIf(IntPtrEqual(size, IntPtrConstant(0)), if_empty);
   TNode<JSArray> array = AllocateJSArray(array_map, result, SmiTag(size));
-  return TNode<JSArray>::UncheckedCast(array);
+  return array;
 }
 
 TF_BUILTIN(ObjectPrototypeHasOwnProperty, ObjectBuiltinsAssembler) {

src/builtins/convert.tq

@@ -128,10 +128,6 @@ macro Convert<To: type, From: type>(i: From): To labels Overflow {
 Convert<Boolean, bool>(b: bool): Boolean {
   return b ? True : False;
 }
-extern macro ConvertElementsKindToInt(ElementsKind): int32;
-Convert<int32, ElementsKind>(elementsKind: ElementsKind): int32 {
-  return ConvertElementsKindToInt(elementsKind);
-}
 Convert<Number, int32>(i: int32): Number {
   return ChangeInt32ToTagged(i);
 }

src/builtins/promise-all-element-closure.tq

@@ -60,7 +60,7 @@ struct PromiseAllSettledWrapResultAsRejectedFunctor {
   }
 }
 
-extern macro LoadJSReceiverIdentityHash(Object): intptr labels IfNoHash;
+extern macro LoadJSReceiverIdentityHash(JSReceiver): intptr labels IfNoHash;
 
 type PromiseAllResolveElementContext extends FunctionContext;
 extern enum PromiseAllResolveElementContextSlots extends intptr

src/codegen/code-stub-assembler.cc

@@ -350,7 +350,7 @@ TNode<Float64T> CodeStubAssembler::Float64Round(TNode<Float64T> x) {
   Goto(&return_x);
 
   BIND(&return_x);
-  return TNode<Float64T>::UncheckedCast(var_x.value());
+  return var_x.value();
 }
 
 TNode<Float64T> CodeStubAssembler::Float64Ceil(TNode<Float64T> x) {
@@ -402,7 +402,7 @@ TNode<Float64T> CodeStubAssembler::Float64Ceil(TNode<Float64T> x) {
   Goto(&return_x);
 
   BIND(&return_x);
-  return TNode<Float64T>::UncheckedCast(var_x.value());
+  return var_x.value();
 }
 
 TNode<Float64T> CodeStubAssembler::Float64Floor(TNode<Float64T> x) {
@@ -454,7 +454,7 @@ TNode<Float64T> CodeStubAssembler::Float64Floor(TNode<Float64T> x) {
   Goto(&return_x);
 
   BIND(&return_x);
-  return TNode<Float64T>::UncheckedCast(var_x.value());
+  return var_x.value();
 }
 
 TNode<Float64T> CodeStubAssembler::Float64RoundToEven(TNode<Float64T> x) {
@@ -485,7 +485,7 @@ TNode<Float64T> CodeStubAssembler::Float64RoundToEven(TNode<Float64T> x) {
   Goto(&done);
 
   BIND(&done);
-  return TNode<Float64T>::UncheckedCast(var_result.value());
+  return var_result.value();
 }
 
 TNode<Float64T> CodeStubAssembler::Float64Trunc(TNode<Float64T> x) {
@@ -546,7 +546,7 @@ TNode<Float64T> CodeStubAssembler::Float64Trunc(TNode<Float64T> x) {
   Goto(&return_x);
 
   BIND(&return_x);
-  return TNode<Float64T>::UncheckedCast(var_x.value());
+  return var_x.value();
 }
 
 template <>
@@ -1776,19 +1776,17 @@ TNode<Uint32T> CodeStubAssembler::EnsureOnlyHasSimpleProperties(
 }
 
 TNode<IntPtrT> CodeStubAssembler::LoadJSReceiverIdentityHash(
-    TNode<Object> receiver, Label* if_no_hash) {
+    TNode<JSReceiver> receiver, Label* if_no_hash) {
   TVARIABLE(IntPtrT, var_hash);
   Label done(this), if_smi(this), if_property_array(this),
       if_ordered_property_dictionary(this), if_property_dictionary(this),
       if_fixed_array(this);
 
   TNode<Object> properties_or_hash =
-      LoadObjectField(TNode<HeapObject>::UncheckedCast(receiver),
-                      JSReceiver::kPropertiesOrHashOffset);
+      LoadObjectField(receiver, JSReceiver::kPropertiesOrHashOffset);
   GotoIf(TaggedIsSmi(properties_or_hash), &if_smi);
 
-  TNode<HeapObject> properties =
-      TNode<HeapObject>::UncheckedCast(properties_or_hash);
+  TNode<HeapObject> properties = CAST(properties_or_hash);
   TNode<Uint16T> properties_instance_type = LoadInstanceType(properties);
 
   GotoIf(InstanceTypeEqual(properties_instance_type, PROPERTY_ARRAY_TYPE),
@@ -1809,7 +1807,7 @@ TNode<IntPtrT> CodeStubAssembler::LoadJSReceiverIdentityHash(
 
   BIND(&if_smi);
   {
-    var_hash = SmiUntag(TNode<Smi>::UncheckedCast(properties_or_hash));
+    var_hash = SmiUntag(CAST(properties_or_hash));
     Goto(&done);
   }
 
@@ -1817,8 +1815,7 @@ TNode<IntPtrT> CodeStubAssembler::LoadJSReceiverIdentityHash(
   {
     TNode<IntPtrT> length_and_hash = LoadAndUntagObjectField(
         properties, PropertyArray::kLengthAndHashOffset);
-    var_hash = TNode<IntPtrT>::UncheckedCast(
-        DecodeWord<PropertyArray::HashField>(length_and_hash));
+    var_hash = Signed(DecodeWord<PropertyArray::HashField>(length_and_hash));
     Goto(&done);
   }
   if (V8_DICT_MODE_PROTOTYPES_BOOL) {
@@ -2695,9 +2692,8 @@ TNode<BoolT> CodeStubAssembler::IsGeneratorFunction(
 TNode<BoolT> CodeStubAssembler::IsJSFunctionWithPrototypeSlot(
     TNode<HeapObject> object) {
   // Only JSFunction maps may have HasPrototypeSlotBit set.
-  return TNode<BoolT>::UncheckedCast(
-      IsSetWord32<Map::Bits1::HasPrototypeSlotBit>(
-          LoadMapBitField(LoadMap(object))));
+  return IsSetWord32<Map::Bits1::HasPrototypeSlotBit>(
+      LoadMapBitField(LoadMap(object)));
 }
 
 void CodeStubAssembler::BranchIfHasPrototypeProperty(
@@ -2868,7 +2864,7 @@ void CodeStubAssembler::StoreFixedArrayOrPropertyArrayElement(
               [=] {
                 TNode<IntPtrT> length_and_hash = LoadAndUntagObjectField(
                     object, PropertyArray::kLengthAndHashOffset);
-                return TNode<IntPtrT>::UncheckedCast(
+                return Signed(
                     DecodeWord<PropertyArray::LengthField>(length_and_hash));
               },
               [=] {

src/codegen/code-stub-assembler.h

@@ -777,20 +777,20 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
   template <class... TArgs>
   TNode<Object> Call(TNode<Context> context, TNode<Object> callable,
                      TNode<JSReceiver> receiver, TArgs... args) {
-    return UncheckedCast<Object>(CallJS(
+    return CallJS(
         CodeFactory::Call(isolate(), ConvertReceiverMode::kNotNullOrUndefined),
-        context, callable, receiver, args...));
+        context, callable, receiver, args...);
   }
   template <class... TArgs>
   TNode<Object> Call(TNode<Context> context, TNode<Object> callable,
                      TNode<Object> receiver, TArgs... args) {
     if (IsUndefinedConstant(receiver) || IsNullConstant(receiver)) {
-      return UncheckedCast<Object>(CallJS(
+      return CallJS(
           CodeFactory::Call(isolate(), ConvertReceiverMode::kNullOrUndefined),
-          context, callable, receiver, args...));
+          context, callable, receiver, args...);
     }
-    return UncheckedCast<Object>(CallJS(CodeFactory::Call(isolate()), context,
-                                        callable, receiver, args...));
+    return CallJS(CodeFactory::Call(isolate()), context, callable, receiver,
+                  args...);
   }
 
   TNode<Object> CallApiCallback(TNode<Object> context, TNode<RawPtrT> callback,
@@ -1271,7 +1271,7 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
                                                TNode<Int32T> instance_type,
                                                Label* bailout);
   // Load the identity hash of a JSRececiver.
-  TNode<IntPtrT> LoadJSReceiverIdentityHash(TNode<Object> receiver,
+  TNode<IntPtrT> LoadJSReceiverIdentityHash(TNode<JSReceiver> receiver,
                                             Label* if_no_hash = nullptr);
 
   // This is only used on a newly allocated PropertyArray which
@@ -2022,10 +2022,6 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
     return UncheckedCast<FixedDoubleArray>(base);
   }
 
-  TNode<Int32T> ConvertElementsKindToInt(TNode<Int32T> elements_kind) {
-    return UncheckedCast<Int32T>(elements_kind);
-  }
-
   template <typename T>
   bool ClassHasMapConstant() {
     return false;