[CSA][cleanup] TNodified some CSA methods relating to Strings

This is a CL in a string of CLs that aims to TNodify CSA. In particular,
there were some loads that were done in AnyTagged instead of
TaggedPointer. TNode-ifying them brings improvement in pointer
compression since we are able to decompress using the Pointer
decompression.

Bug: v8:6949, v8:9396
Change-Id: I368d4f85348f3560a7f71bf66ebc7c4dd978a8dd
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1752854Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63274}

src/builtins/builtins-intl-gen.cc

@@ -33,9 +33,7 @@ class IntlBuiltinsAssembler : public CodeStubAssembler {
 };
 
 TF_BUILTIN(StringToLowerCaseIntl, IntlBuiltinsAssembler) {
-  Node* const string = Parameter(Descriptor::kString);
-
-  CSA_ASSERT(this, IsString(string));
+  TNode<String> const string = CAST(Parameter(Descriptor::kString));
 
   Label call_c(this), return_string(this), runtime(this, Label::kDeferred);
 
@@ -49,7 +47,7 @@ TF_BUILTIN(StringToLowerCaseIntl, IntlBuiltinsAssembler) {
       state(), string, ToDirectStringAssembler::kDontUnpackSlicedStrings);
   to_direct.TryToDirect(&runtime);
 
-  Node* const instance_type = to_direct.instance_type();
+  TNode<Int32T> const instance_type = to_direct.instance_type();
   CSA_ASSERT(this,
              Word32BinaryNot(IsIndirectStringInstanceType(instance_type)));
   GotoIfNot(IsOneByteStringInstanceType(instance_type), &runtime);
@@ -67,7 +65,7 @@ TF_BUILTIN(StringToLowerCaseIntl, IntlBuiltinsAssembler) {
     VARIABLE(var_cursor, MachineType::PointerRepresentation(),
              IntPtrConstant(0));
 
-    Node* const start_address = to_direct.PointerToData(&call_c);
+    TNode<RawPtrT> const start_address = to_direct.PointerToData(&call_c);
     TNode<IntPtrT> const end_address =
         Signed(IntPtrAdd(start_address, ChangeUint32ToWord(length)));
 
@@ -105,7 +103,7 @@ TF_BUILTIN(StringToLowerCaseIntl, IntlBuiltinsAssembler) {
   // String ConvertOneByteToLower(String src, String dst);
   BIND(&call_c);
   {
-    Node* const src = to_direct.string();
+    TNode<String> const src = to_direct.string();
 
     Node* const function_addr =
         ExternalConstant(ExternalReference::intl_convert_one_byte_to_lower());

src/builtins/builtins-string-gen.h

@@ -58,16 +58,17 @@ class StringBuiltinsAssembler : public CodeStubAssembler {
   void ConvertAndBoundsCheckStartArgument(Node* context, Variable* var_start,
                                           Node* start, Node* string_length);
 
-  void GenerateStringEqual(Node* left, Node* right);
-  void GenerateStringRelationalComparison(Node* left, Node* right,
-                                          Operation op);
+  void GenerateStringEqual(TNode<String> left, TNode<String> right);
+  void GenerateStringRelationalComparison(TNode<String> left,
+                                          TNode<String> right, Operation op);
 
   using StringAtAccessor = std::function<TNode<Object>(
       TNode<String> receiver, TNode<IntPtrT> length, TNode<IntPtrT> index)>;
 
-  void StringIndexOf(Node* const subject_string, Node* const search_string,
-                     Node* const position,
-                     const std::function<void(Node*)>& f_return);
+  void StringIndexOf(TNode<String> const subject_string,
+                     TNode<String> const search_string,
+                     TNode<Smi> const position,
+                     const std::function<void(TNode<Smi>)>& f_return);
 
   TNode<Smi> IndexOfDollarChar(Node* const context, Node* const string);
 

src/codegen/code-stub-assembler.h

@@ -2422,20 +2422,26 @@ class V8_EXPORT_PRIVATE CodeStubAssembler
 
   // Check if |string| is an indirect (thin or flat cons) string type that can
   // be dereferenced by DerefIndirectString.
-  void BranchIfCanDerefIndirectString(Node* string, Node* instance_type,
+  void BranchIfCanDerefIndirectString(TNode<String> string,
+                                      TNode<Int32T> instance_type,
                                       Label* can_deref, Label* cannot_deref);
   // Unpack an indirect (thin or flat cons) string type.
-  void DerefIndirectString(Variable* var_string, Node* instance_type);
+  void DerefIndirectString(TVariable<String>* var_string,
+                           TNode<Int32T> instance_type);
   // Check if |var_string| has an indirect (thin or flat cons) string type,
   // and unpack it if so.
-  void MaybeDerefIndirectString(Variable* var_string, Node* instance_type,
-                                Label* did_deref, Label* cannot_deref);
+  void MaybeDerefIndirectString(TVariable<String>* var_string,
+                                TNode<Int32T> instance_type, Label* did_deref,
+                                Label* cannot_deref);
   // Check if |var_left| or |var_right| has an indirect (thin or flat cons)
   // string type, and unpack it/them if so. Fall through if nothing was done.
-  void MaybeDerefIndirectStrings(Variable* var_left, Node* left_instance_type,
-                                 Variable* var_right, Node* right_instance_type,
+  void MaybeDerefIndirectStrings(TVariable<String>* var_left,
+                                 TNode<Int32T> left_instance_type,
+                                 TVariable<String>* var_right,
+                                 TNode<Int32T> right_instance_type,
                                  Label* did_something);
-  Node* DerefIndirectString(TNode<String> string, TNode<Int32T> instance_type,
+  TNode<String> DerefIndirectString(TNode<String> string,
+                                    TNode<Int32T> instance_type,
                                     Label* cannot_deref);
 
   TNode<String> StringFromSingleUTF16EncodedCodePoint(TNode<Int32T> codepoint);
@@ -3705,8 +3711,8 @@ class ToDirectStringAssembler : public CodeStubAssembler {
   };
   using Flags = base::Flags<Flag>;
 
-  ToDirectStringAssembler(compiler::CodeAssemblerState* state, Node* string,
-                          Flags flags = Flags());
+  ToDirectStringAssembler(compiler::CodeAssemblerState* state,
+                          TNode<String> string, Flags flags = Flags());
 
   // Converts flat cons, thin, and sliced strings and returns the direct
   // string. The result can be either a sequential or external string.
@@ -3726,20 +3732,18 @@ class ToDirectStringAssembler : public CodeStubAssembler {
     return TryToSequential(PTR_TO_STRING, if_bailout);
   }
 
-  Node* string() { return var_string_.value(); }
-  Node* instance_type() { return var_instance_type_.value(); }
-  TNode<IntPtrT> offset() {
-    return UncheckedCast<IntPtrT>(var_offset_.value());
-  }
-  Node* is_external() { return var_is_external_.value(); }
+  TNode<String> string() { return var_string_.value(); }
+  TNode<Int32T> instance_type() { return var_instance_type_.value(); }
+  TNode<IntPtrT> offset() { return var_offset_.value(); }
+  TNode<Word32T> is_external() { return var_is_external_.value(); }
 
  private:
   TNode<RawPtrT> TryToSequential(StringPointerKind ptr_kind, Label* if_bailout);
 
-  Variable var_string_;
-  Variable var_instance_type_;
-  Variable var_offset_;
-  Variable var_is_external_;
+  TVariable<String> var_string_;
+  TVariable<Int32T> var_instance_type_;
+  TVariable<IntPtrT> var_offset_;
+  TVariable<Word32T> var_is_external_;
 
   const Flags flags_;
 };