[string] Move String.p.toLowerCase to CSA

src/code-stub-assembler.h

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_CODE_STUB_ASSEMBLER_H_
 #define V8_CODE_STUB_ASSEMBLER_H_
 
 #include <functional>
 
 #include "src/compiler/code-assembler.h"
@@ skipping 402 matching lines @@
 
   // Load the hash field of a name as an uint32 value.
   Node* LoadNameHashField(Node* name);
   // Load the hash value of a name as an uint32 value.
   // If {if_hash_not_computed} label is specified then it also checks if
   // hash is actually computed.
   Node* LoadNameHash(Node* name, Label* if_hash_not_computed = nullptr);
 
   // Load length field of a String object.
   Node* LoadStringLength(Node* object);
+  // Loads a pointer to the sequential String char array.
+  Node* PointerToSeqStringData(Node* seq_string);
   // Load value field of a JSValue object.
   Node* LoadJSValueValue(Node* object);
   // Load value field of a WeakCell object.
   Node* LoadWeakCellValueUnchecked(Node* weak_cell);
   Node* LoadWeakCellValue(Node* weak_cell, Label* if_cleared = nullptr);
 
   // Load an array element from a FixedArray.
   Node* LoadFixedArrayElement(Node* object, Node* index,
                               int additional_offset = 0,
                               ParameterMode parameter_mode = INTPTR_PARAMETERS);
@@ skipping 300 matching lines @@
   // JSProxy or an object with interceptors.
   Node* InstanceTypeEqual(Node* instance_type, int type);
   Node* IsSpecialReceiverMap(Node* map);
   Node* IsSpecialReceiverInstanceType(Node* instance_type);
   Node* IsStringInstanceType(Node* instance_type);
   Node* IsOneByteStringInstanceType(Node* instance_type);
   Node* IsExternalStringInstanceType(Node* instance_type);
   Node* IsShortExternalStringInstanceType(Node* instance_type);
   Node* IsSequentialStringInstanceType(Node* instance_type);
   Node* IsConsStringInstanceType(Node* instance_type);
+  Node* IsIndirectStringInstanceType(Node* instance_type);
   Node* IsString(Node* object);
   Node* IsJSObject(Node* object);
   Node* IsJSGlobalProxy(Node* object);
   Node* IsJSReceiverInstanceType(Node* instance_type);
   Node* IsJSReceiver(Node* object);
   Node* IsJSReceiverMap(Node* map);
   Node* IsMap(Node* object);
   Node* IsCallableMap(Node* map);
   Node* IsDeprecatedMap(Node* map);
   Node* IsCallable(Node* object);
@@ skipping 769 matching lines @@
   Node* argc_;
   Node* arguments_;
   Node* fp_;
 };
 
 class ToDirectStringAssembler : public CodeStubAssembler {
  private:
   enum StringPointerKind { PTR_TO_DATA, PTR_TO_STRING };
 
  public:
-  explicit ToDirectStringAssembler(compiler::CodeAssemblerState* state,
-                                   Node* string);
+  enum Flag {
+    kDontUnpackSlicedStrings = 1 << 0,
+  };
+  typedef base::Flags<Flag> Flags;
+
+  ToDirectStringAssembler(compiler::CodeAssemblerState* state, Node* 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.
+  // Jumps to if_bailout if the string if the string is indirect and cannot
+  // be unpacked.
   Node* TryToDirect(Label* if_bailout);
 
   // Returns a pointer to the beginning of the string data.
+  // Jumps to if_bailout if the external string cannot be unpacked.
   Node* PointerToData(Label* if_bailout) {
     return TryToSequential(PTR_TO_DATA, if_bailout);
   }
 
   // Returns a pointer that, offset-wise, looks like a String.
+  // Jumps to if_bailout if the external string cannot be unpacked.
   Node* PointerToString(Label* if_bailout) {
     return TryToSequential(PTR_TO_STRING, if_bailout);
   }
 
   Node* string() { return var_string_.value(); }
   Node* instance_type() { return var_instance_type_.value(); }
   Node* offset() { return var_offset_.value(); }
   Node* is_external() { return var_is_external_.value(); }
 
  private:
   Node* TryToSequential(StringPointerKind ptr_kind, Label* if_bailout);
 
   Variable var_string_;
   Variable var_instance_type_;
   Variable var_offset_;
   Variable var_is_external_;
+
+  Flags flags_;
 };
 
 #ifdef DEBUG
 #define CSA_ASSERT(csa, x) \
   (csa)->Assert([&] { return (x); }, #x, __FILE__, __LINE__)
 #define CSA_ASSERT_JS_ARGC_OP(csa, Op, op, expected)             \
   (csa)->Assert(                                                 \
       [&] {                                                      \
         compiler::Node* const argc =                             \
             (csa)->Parameter(Descriptor::kActualArgumentsCount); \
@@ skipping 22 matching lines @@
   }
 #else
 #define CSA_SLOW_ASSERT(csa, x) ((void)0)
 #endif
 
 DEFINE_OPERATORS_FOR_FLAGS(CodeStubAssembler::AllocationFlags);
 
 }  // namespace internal
 }  // namespace v8
 #endif  // V8_CODE_STUB_ASSEMBLER_H_