[stubs] Add String and JSReceiver instance type predicates

src/builtins/builtins-object.cc

 // 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.
 
 #include "src/builtins/builtins.h"
 #include "src/builtins/builtins-utils.h"
 
 #include "src/code-factory.h"
 #include "src/property-descriptor.h"
 
@@ skipping 212 matching lines @@
   typedef compiler::Node Node;
   typedef CodeStubAssembler::Label Label;
 
   Label if_notsmi(assembler);
   assembler->Branch(assembler->WordIsSmi(object), if_notstring, &if_notsmi);
 
   assembler->Bind(&if_notsmi);
   {
     Node* instance_type = assembler->LoadInstanceType(object);
 
-    assembler->Branch(
-        assembler->Int32LessThan(
-            instance_type, assembler->Int32Constant(FIRST_NONSTRING_TYPE)),
-        if_string, if_notstring);
+    assembler->Branch(assembler->IsStringInstanceType(instance_type), if_string,
+                      if_notstring);
   }
 }
 
 void ReturnToStringFormat(CodeStubAssembler* assembler, compiler::Node* context,
                           compiler::Node* string) {
   typedef compiler::Node Node;
 
   Node* lhs = assembler->HeapConstant(
       assembler->factory()->NewStringFromStaticChars("[object "));
   Node* rhs = assembler->HeapConstant(
       assembler->factory()->NewStringFromStaticChars("]"));
 
   Callable callable = CodeFactory::StringAdd(
       assembler->isolate(), STRING_ADD_CHECK_NONE, NOT_TENURED);
 
   assembler->Return(assembler->CallStub(
       callable, context, assembler->CallStub(callable, context, lhs, string),
       rhs));
 }
 
 void ReturnIfPrimitive(CodeStubAssembler* assembler,
                        compiler::Node* instance_type,
                        CodeStubAssembler::Label* return_string,
                        CodeStubAssembler::Label* return_boolean,
                        CodeStubAssembler::Label* return_number) {
-  assembler->GotoIf(
-      assembler->Int32LessThan(instance_type,
-                               assembler->Int32Constant(FIRST_NONSTRING_TYPE)),
-      return_string);
+  assembler->GotoIf(assembler->IsStringInstanceType(instance_type),
+                    return_string);
 
   assembler->GotoIf(assembler->Word32Equal(
                         instance_type, assembler->Int32Constant(ODDBALL_TYPE)),
                     return_boolean);
 
   assembler->GotoIf(
       assembler->Word32Equal(instance_type,
                              assembler->Int32Constant(HEAP_NUMBER_TYPE)),
       return_number);
 }
@@ skipping 629 matching lines @@
   if (object->IsJSReceiver()) {
     MAYBE_RETURN(JSReceiver::SetIntegrityLevel(Handle<JSReceiver>::cast(object),
                                                SEALED, Object::THROW_ON_ERROR),
                  isolate->heap()->exception());
   }
   return *object;
 }
 
 }  // namespace internal
 }  // namespace v8