[cleanup] Make ChangeNumberToFloat64() require TNode<Number>.

This addresses a TODO and makes the CAST explicit at the use sites,
which in turn makes it easier to understand the implications there.

Bug: v8:9183
Change-Id: I5b285a5a0ba6b754b4de9d60ff6e18c2e807bf98
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1649569
Auto-Submit: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62079}

src/codegen/code-stub-assembler.cc

@@ -3019,7 +3019,7 @@ void CodeStubAssembler::TryStoreArrayElement(ElementsKind kind,
     GotoIfNotNumber(value, bailout);
   }
   if (IsDoubleElementsKind(kind)) {
-    value = ChangeNumberToFloat64(value);
+    value = ChangeNumberToFloat64(CAST(value));
   }
   StoreElement(elements, kind, index, value, mode);
 }
@@ -5750,10 +5750,7 @@ TNode<Uint32T> CodeStubAssembler::ChangeNumberToUint32(TNode<Number> value) {
   return var_result.value();
 }
 
-TNode<Float64T> CodeStubAssembler::ChangeNumberToFloat64(
-    SloppyTNode<Number> value) {
-  // TODO(tebbi): Remove assert once argument is TNode instead of SloppyTNode.
-  CSA_SLOW_ASSERT(this, IsNumber(value));
+TNode<Float64T> CodeStubAssembler::ChangeNumberToFloat64(TNode<Number> value) {
   TVARIABLE(Float64T, result);
   Label smi(this);
   Label done(this, &result);

src/codegen/code-stub-assembler.h

@@ -2103,7 +2103,7 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
   TNode<Number> ChangeUint32ToTagged(SloppyTNode<Uint32T> value);
   TNode<Number> ChangeUintPtrToTagged(TNode<UintPtrT> value);
   TNode<Uint32T> ChangeNumberToUint32(TNode<Number> value);
-  TNode<Float64T> ChangeNumberToFloat64(SloppyTNode<Number> value);
+  TNode<Float64T> ChangeNumberToFloat64(TNode<Number> value);
   TNode<UintPtrT> TryNumberToUintPtr(TNode<Number> value, Label* if_negative);
   TNode<UintPtrT> ChangeNonnegativeNumberToUintPtr(TNode<Number> value) {
     return TryNumberToUintPtr(value, nullptr);

src/ic/accessor-assembler.cc

@@ -1207,7 +1207,7 @@ void AccessorAssembler::OverwriteExistingFastDataProperty(
           &double_rep, &tagged_rep);
       BIND(&double_rep);
       {
-        TNode<Float64T> double_value = ChangeNumberToFloat64(value);
+        TNode<Float64T> double_value = ChangeNumberToFloat64(CAST(value));
         if (FLAG_unbox_double_fields) {
           if (do_transitioning_store) {
             StoreMap(object, object_map);
@@ -1275,7 +1275,7 @@ void AccessorAssembler::OverwriteExistingFastDataProperty(
                                 Int32Constant(Representation::kDouble)),
                  &cont);
           {
-            Node* double_value = ChangeNumberToFloat64(value);
+            Node* double_value = ChangeNumberToFloat64(CAST(value));
             Node* mutable_heap_number =
                 AllocateMutableHeapNumberWithValue(double_value);
             var_value.Bind(mutable_heap_number);
@@ -1301,7 +1301,7 @@ void AccessorAssembler::OverwriteExistingFastDataProperty(
         {
           Node* mutable_heap_number =
               LoadPropertyArrayElement(properties, backing_store_index);
-          TNode<Float64T> double_value = ChangeNumberToFloat64(value);
+          TNode<Float64T> double_value = ChangeNumberToFloat64(CAST(value));
 
           Label if_mutable(this);
           GotoIfNot(IsPropertyDetailsConst(details), &if_mutable);