Add a flags field to RawObject so that we can tag objects with certain

vm/stub_code_ia32.cc

 // Copyright (c) 2011, 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"
 #if defined(TARGET_ARCH_IA32)
 
 #include "vm/code_generator.h"
 #include "vm/compiler.h"
 #include "vm/ic_data.h"
@@ skipping 676 matching lines @@
     __ movl(FieldAddress(EAX, Array::type_arguments_offset()), ECX);
 
     // Set the length field.
     __ movl(FieldAddress(EAX, Array::length_offset()), EDX);
 
     // Store class value for array.
     __ movl(ECX, FieldAddress(CTX, Context::isolate_offset()));
     __ movl(ECX, Address(ECX, Isolate::object_store_offset()));
     __ movl(ECX, Address(ECX, ObjectStore::array_class_offset()));
     __ movl(FieldAddress(EAX, Array::class_offset()), ECX);
+    __ movl(FieldAddress(EAX, Array::tags_offset()), Immediate(0));  // Tags.
 
     // Initialize all array elements to raw_null.
     // EAX: new object start as a tagged pointer.
     // EBX: new object end address.
     // ECX: iterator which initially points to the start of the variable
     // data area to be initialized.
     __ leal(ECX, FieldAddress(EAX, Array::data_offset()));
     Label done;
     Label init_loop;
     __ Bind(&init_loop);
@@ skipping 280 matching lines @@
     // EBX: next object start.
     // EDX: number of context variables.
     __ movl(Address::Absolute(heap->TopAddress()), EBX);
     __ addl(EAX, Immediate(kHeapObjectTag));
 
     // Initialize the class field in the context object.
     // EAX: new object.
     // EDX: number of context variables.
     __ LoadObject(EBX, context_class);  // Load up class field of context.
     __ movl(FieldAddress(EAX, Context::class_offset()), EBX);
+    __ movl(FieldAddress(EAX, Context::tags_offset()), Immediate(0));  // Tags.
 
     // Setup up number of context variables field.
     // EAX: new object.
     // EDX: number of context variables.
     __ movl(FieldAddress(EAX, Context::num_variables_offset()), EDX);
 
     // Setup isolate field.
     // Load Isolate pointer from Context structure into EBX.
     // EAX: new object.
     // EDX: number of context variables.
@@ skipping 113 matching lines @@
       __ movl(Address(ECX,
           InstantiatedTypeArguments::uninstantiated_type_arguments_offset()),
               EDI);
       __ movl(EDX, Address(ESP, kInstantiatorTypeArgumentsOffset));
       __ movl(Address(ECX,
           InstantiatedTypeArguments::instantiator_type_arguments_offset()),
               EDX);
       __ LoadObject(EDX,
           Class::ZoneHandle(Object::instantiated_type_arguments_class()));
       __ movl(Address(ECX, Instance::class_offset()), EDX);  // Set its class.
+      __ movl(Address(ECX, Instance::tags_offset()), Immediate(0));  // Tags.
       // Set the new InstantiatedTypeArguments object (ECX) as the type
       // arguments (EDI) of the new object (EAX).
       __ movl(EDI, ECX);
       __ addl(EDI, Immediate(kHeapObjectTag));
       // Set EBX to new object end.
       __ movl(EBX, ECX);
       __ Bind(&type_arguments_ready);
       // EAX: new object.
       // EDI: new object type arguments.
     }
 
     // Initialize the class field in the object.
     // EAX: new object start.
     // EBX: next object start.
     // EDI: new object type arguments (if is_cls_parameterized).
     __ LoadObject(EDX, cls);  // Load class of object to be allocated.
     __ movl(Address(EAX, Instance::class_offset()), EDX);
+    __ movl(Address(EAX, Instance::tags_offset()), Immediate(0));  // Tags.
 
     // Initialize the remaining words of the object.
     const Immediate raw_null =
         Immediate(reinterpret_cast<intptr_t>(Object::null()));
 
     // EAX: new object start.
     // EBX: next object start.
     // EDX: class of the object to be allocated.
     // First try inlining the initialization without a loop.
     if (instance_size < (kInlineInstanceSize * kWordSize) &&
         cls.num_native_fields() == 0) {
       // Check if the object contains any non-header fields.
       // Small objects are initialized using a consecutive set of writes.
-      for (intptr_t current_offset = 1 * kWordSize;
+      for (intptr_t current_offset = sizeof(RawObject);
            current_offset < instance_size;
            current_offset += kWordSize) {
         __ movl(Address(EAX, current_offset), raw_null);
       }
     } else {
-      __ leal(ECX, Address(EAX, 1 * kWordSize));
+      __ leal(ECX, Address(EAX, sizeof(RawObject)));
       // Loop until the whole object is initialized.
       Label init_loop;
       if (cls.num_native_fields() > 0) {
         // Initialize native fields.
         // EAX: new object.
         // EBX: next object start.
         // EDX: class of the object to be allocated.
         // ECX: next word to be initialized.
         intptr_t offset = Class::num_native_fields_offset() - kHeapObjectTag;
         __ movl(EDX, Address(EDX, offset));
-        __ leal(EDX, Address(EAX, EDX, TIMES_4, 0));
+        __ leal(EDX, Address(EAX, EDX, TIMES_4, sizeof(RawObject)));
 
         // EDX: start of dart fields.
         // ECX: next word to be initialized.
         Label init_native_loop;
         __ Bind(&init_native_loop);
         __ cmpl(ECX, EDX);
         __ j(ABOVE_EQUAL, &init_loop, Assembler::kNearJump);
         __ movl(Address(ECX, 0), Immediate(0));
         __ addl(ECX, Immediate(kWordSize));
         __ jmp(&init_native_loop, Assembler::kNearJump);
@@ skipping 97 matching lines @@
 
     // Successfully allocated the object, now update top to point to
     // next object start and initialize the object.
     __ movl(Address::Absolute(heap->TopAddress()), EBX);
 
     // Initialize the class field in the object.
     // EAX: new closure object.
     // ECX: new context object (only if is_implicit_closure).
     __ LoadObject(EDX, cls);  // Load signature class of closure.
     __ movl(Address(EAX, Closure::class_offset()), EDX);
+    __ movl(Address(EAX, Closure::tags_offset()), Immediate(0));  // Tags.
 
     // Initialize the function field in the object.
     // EAX: new closure object.
     // ECX: new context object (only if is_implicit_closure).
     // EBX: next object start.
     __ LoadObject(EDX, func);  // Load function of closure to be allocated.
     __ movl(Address(EAX, Closure::function_offset()), EDX);
 
     // Setup the context for this closure.
     if (is_implicit_static_closure) {
       ObjectStore* object_store = Isolate::Current()->object_store();
       ASSERT(object_store != NULL);
       const Context& empty_context =
           Context::ZoneHandle(object_store->empty_context());
       __ LoadObject(EDX, empty_context);
       __ movl(Address(EAX, Closure::context_offset()), EDX);
     } else if (is_implicit_instance_closure) {
       // Initialize the new context capturing the receiver.
 
       // Set the class field to the Context class.
       __ LoadObject(EBX, Class::ZoneHandle(Object::context_class()));
       __ movl(Address(ECX, Context::class_offset()), EBX);
+      __ movl(Address(ECX, Context::tags_offset()), Immediate(0));  // Tags.
 
       // Set number of variables field to 1 (for captured receiver).
       __ movl(Address(ECX, Context::num_variables_offset()), Immediate(1));
 
       // Set isolate field to isolate of current context.
       __ movl(EDX, FieldAddress(CTX, Context::isolate_offset()));
       __ movl(Address(ECX, Context::isolate_offset()), EDX);
 
       // Set the parent field to null.
       __ movl(Address(ECX, Context::parent_offset()), raw_null);
@@ skipping 251 matching lines @@
   __ popl(EDX);
   __ popl(ECX);
   __ LeaveFrame();
   // Now call the dynamic function.
   __ jmp(&StubCode::InlineCacheLabel());
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_IA32