Request for comments on overall approach.

runtime/vm/code_generator_ia32.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_IA32.
 #if defined(TARGET_ARCH_IA32)
 
 #include "vm/code_generator.h"
 
 #include "lib/error.h"
@@ skipping 1215 matching lines @@
     intptr_t token_index,
     const Class& type_class,
     Label* is_instance_lbl,
     Label* is_not_instance_lbl) {
   const SubtypeTestCache& type_test_cache =
       SubtypeTestCache::ZoneHandle(SubtypeTestCache::New());
   const Bool& bool_true = Bool::ZoneHandle(Bool::True());
   const Immediate raw_null =
       Immediate(reinterpret_cast<intptr_t>(Object::null()));
   // Check immediate equality.
-  __ movl(ECX, FieldAddress(EAX, Object::class_offset()));
+  __ GetClassOf(ECX, EAX, EDI);
   // ECX: instance class.
   __ CompareObject(ECX, type_class);
   __ j(EQUAL, is_instance_lbl);
 
   // Check immediate superclass equality.
   __ movl(EDI, FieldAddress(ECX, Class::super_type_offset()));
   __ movl(EDI, FieldAddress(EDI, Type::type_class_offset()));
   __ CompareObject(EDI, type_class);
   __ j(EQUAL, is_instance_lbl);
 
@@ skipping 200 matching lines @@
   // A class equality check is only applicable with a dst type of a
   // non-parameterized class or with a raw dst type of a parameterized class.
   __ testl(EAX, Immediate(kSmiTagMask));
   __ j(ZERO, is_not_instance_lbl);
   const AbstractTypeArguments& type_arguments =
       AbstractTypeArguments::ZoneHandle(type.arguments());
   const bool is_raw_type = type_arguments.IsNull() ||
       type_arguments.IsRaw(type_arguments.Length());
   if (is_raw_type) {
     // Dynamic type argument, check only classes.
-    __ movl(ECX, FieldAddress(EAX, Object::class_offset()));
+    __ LoadObjectClassId(ECX, EAX);
     if (!type_class.is_interface()) {
-      __ CompareObject(ECX, type_class);
+      __ cmpl(ECX, Immediate(type_class.index()));
       __ j(EQUAL, is_instance_lbl);
     }
     if (type.IsListInterface()) {
       // TODO(srdjan) also accept List<Object>.
-      __ CompareObject(ECX, *CoreClass("ObjectArray"));
+      __ cmpl(ECX, Immediate(CoreClass("ObjectArray")->index()));
       __ j(EQUAL, is_instance_lbl);
-      __ CompareObject(ECX, *CoreClass("GrowableObjectArray"));
+      __ cmpl(ECX, Immediate(CoreClass("GrowableObjectArray")->index()));
       __ j(EQUAL, is_instance_lbl);
     }
     return
         GenerateSubtype1TestCacheLookup(node_id, token_index, type_class,
                                         is_instance_lbl, is_not_instance_lbl);
   }
   // If one type argument only, quick check.
   if (type_arguments.Length() == 1) {
     const AbstractType& tp_argument = AbstractType::ZoneHandle(
         type_arguments.TypeAt(0));
@@ skipping 68 matching lines @@
   } else {
     __ jmp(is_not_instance_lbl);
   }
   // Compare if the classes are equal.
   __ Bind(&compare_classes);
 
   // Checking against interface.
   // However, for specific core library interfaces, we can check for
   // specific core library classes.
   if (type.IsBoolInterface()) {
-    __ movl(ECX, FieldAddress(EAX, Object::class_offset()));
-    const Class& bool_class = Class::ZoneHandle(
+    const Class& bool_class = Class::Handle(
         Isolate::Current()->object_store()->bool_class());
-    __ CompareObject(ECX, bool_class);
+    __ CompareClassOf(EAX, bool_class, ECX);
     __ j(EQUAL, is_instance_lbl);
     __ jmp(is_not_instance_lbl);
     return;
   }
   // If type is an interface, we can skip the class equality check,
   // because instances cannot be of an interface type.
   if (!type_class.is_interface()) {
-    __ movl(ECX, FieldAddress(EAX, Object::class_offset()));
-    __ CompareObject(ECX, type_class);
+    __ CompareClassOf(EAX, type_class, ECX);
     __ j(EQUAL, is_instance_lbl);
   }
   if (type.IsSubtypeOf(
         Type::Handle(Type::NumberInterface()), &malformed_error)) {
     // Custom checking for numbers (Smi, Mint, Bigint and Double)
-    __ movl(ECX, FieldAddress(EAX, Object::class_offset()));
+    __ LoadObjectClassId(ECX, EAX);
+
     if (type.IsIntInterface() || type.IsNumberInterface()) {
       // We already checked for Smi above.
       const Class& mint_class = Class::ZoneHandle(
           Isolate::Current()->object_store()->mint_class());
       const Class& bigint_class = Class::ZoneHandle(
           Isolate::Current()->object_store()->bigint_class());
-      __ CompareObject(ECX, mint_class);
+      __ CompareClassId(ECX, mint_class);
       __ j(EQUAL, is_instance_lbl);
-      __ CompareObject(ECX, bigint_class);
+      __ CompareClassId(ECX, bigint_class);
       __ j(EQUAL, is_instance_lbl);
       if (type.IsIntInterface()) {
         __ jmp(is_not_instance_lbl);
       }
     }
     if (type.IsDoubleInterface() || type.IsNumberInterface()) {
       const Class& double_class = Class::ZoneHandle(
           Isolate::Current()->object_store()->double_class());
-      __ CompareObject(ECX, double_class);
+      __ CompareClassId(ECX, double_class);
       __ j(EQUAL, is_instance_lbl);
       __ jmp(is_not_instance_lbl);
     }
   } else if (type.IsStringInterface()) {
-    __ movl(ECX, FieldAddress(EAX, Object::class_offset()));
+    __ LoadObjectClassId(ECX, EAX);
     const Class& one_byte_string_class = Class::ZoneHandle(
         Isolate::Current()->object_store()->one_byte_string_class());
     const Class& two_byte_string_class = Class::ZoneHandle(
         Isolate::Current()->object_store()->two_byte_string_class());
     const Class& four_byte_string_class = Class::ZoneHandle(
         Isolate::Current()->object_store()->four_byte_string_class());
-    __ CompareObject(ECX, one_byte_string_class);
+    __ CompareClassId(ECX, one_byte_string_class);
     __ j(EQUAL, is_instance_lbl);
-    __ CompareObject(ECX, two_byte_string_class);
+    __ CompareClassId(ECX, two_byte_string_class);
     __ j(EQUAL, is_instance_lbl);
-    __ CompareObject(ECX, four_byte_string_class);
+    __ CompareClassId(ECX, four_byte_string_class);
     __ j(EQUAL, is_instance_lbl);
   } else if (type.IsFunctionInterface()) {
     // Check if instance is a closure.
     const Immediate raw_null =
         Immediate(reinterpret_cast<intptr_t>(Object::null()));
-    __ movl(ECX, FieldAddress(EAX, Object::class_offset()));
+    __ GetClassOf(ECX, EAX, EBX);
     __ movl(ECX, FieldAddress(ECX, Class::signature_function_offset()));
     __ cmpl(ECX, raw_null);
     __ j(NOT_EQUAL, is_instance_lbl);
   }
   // Otherwise fallthrough.
 }
 
 
 // EAX: instance to test.
 // Clobbers: EBX, EDX, ECX.
@@ skipping 15 matching lines @@
     // Type arguments are on stack.
     __ popl(EBX);
     // Check if type argument is dynamic.
     __ cmpl(EBX, raw_null);
     __ j(EQUAL, is_instance_lbl);
 
     // EBX: instantiator type arguments.
     // For now handle only TypeArguments and bail out if InstantiatedTypeArgs.
     // We expect that frequently checked objects wull have their type arguments
     // converted into instance of TypeArguments.
-    __ movl(EDX, FieldAddress(EBX, Object::class_offset()));
-    __ CompareObject(EDX, Object::ZoneHandle(Object::type_arguments_class()));
+    __ CompareClassOf(EBX, Class::Handle(Object::type_arguments_class()), EDX);
     __ j(NOT_EQUAL, &fall_through, Assembler::kNearJump);
 
     __ movl(EDX,
         FieldAddress(EBX, TypeArguments::type_at_offset(type.Index())));
     // EDX: concrete type of type.
     // Check if type argument is dynamic.
     __ CompareObject(EDX, Type::ZoneHandle(Type::DynamicType()));
     __ j(EQUAL,  is_instance_lbl);
     __ cmpl(EDX, raw_null);
     __ j(EQUAL,  is_instance_lbl);
@@ skipping 211 matching lines @@
   Label runtime_call, done;
   __ movl(EAX, Address(ESP, 0));
   __ cmpl(EAX, raw_null);
   __ j(EQUAL, &runtime_call, Assembler::kNearJump);
   __ testl(EAX, Immediate(kSmiTagMask));
   __ j(ZERO, &runtime_call, Assembler::kNearJump);  // Call runtime for Smi.
   // This check should pass if the receiver's class implements the interface
   // 'bool'. Check only class 'Bool' since it is the only legal implementation
   // of the interface 'bool'.
   const Class& bool_class =
-      Class::ZoneHandle(Isolate::Current()->object_store()->bool_class());
-  __ movl(ECX, FieldAddress(EAX, Object::class_offset()));
-  __ CompareObject(ECX, bool_class);
+      Class::Handle(Isolate::Current()->object_store()->bool_class());
+  __ CompareClassOf(EAX, bool_class, ECX);
   __ j(EQUAL, &done, Assembler::kNearJump);
 
   __ Bind(&runtime_call);
   __ pushl(Immediate(Smi::RawValue(token_index)));  // Source location.
   __ pushl(EAX);  // Push the source object.
   GenerateCallRuntime(node_id, token_index, kConditionTypeErrorRuntimeEntry);
   // We should never return here.
   __ int3();
 
   __ Bind(&done);
@@ skipping 621 matching lines @@
       __ cmpl(EAX, raw_null);
       __ j(EQUAL, &type_arguments_instantiated, Assembler::kNearJump);
     }
     // Instantiate non-null type arguments.
     if (type_arguments.IsUninstantiatedIdentity()) {
       // Check if the instantiator type argument vector is a TypeArguments of a
       // matching length and, if so, use it as the instantiated type_arguments.
       // No need to check RAX for null (again), because a null instance will
       // have the wrong class (Null instead of TypeArguments).
       Label type_arguments_uninstantiated;
-      __ LoadObject(ECX, Class::ZoneHandle(Object::type_arguments_class()));
-      __ cmpl(ECX, FieldAddress(EAX, Object::class_offset()));
+      __ CompareClassOf(EAX,
+                        Class::Handle(Object::type_arguments_class()),
+                        ECX);
       __ j(NOT_EQUAL, &type_arguments_uninstantiated, Assembler::kNearJump);
       __ cmpl(FieldAddress(EAX, TypeArguments::length_offset()),
               Immediate(Smi::RawValue(len)));
       __ j(EQUAL, &type_arguments_instantiated, Assembler::kNearJump);
       __ Bind(&type_arguments_uninstantiated);
     }
     if (instantiate_type_arguments) {
       // A runtime call to instantiate the type arguments is required.
       __ PushObject(Object::ZoneHandle());  // Make room for the result.
       __ PushObject(type_arguments);
@@ skipping 445 matching lines @@
   const Error& error = Error::Handle(
       Parser::FormatError(script, token_index, "Error", format, args));
   va_end(args);
   Isolate::Current()->long_jump_base()->Jump(1, error);
   UNREACHABLE();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_IA32