Initial SIMDBC interpreter.

runtime/vm/object.cc

Index: runtime/vm/object.cc
diff --git a/runtime/vm/object.cc b/runtime/vm/object.cc
index 93ad49ce7a1d48d62baa1493e3ae2889d312a642..e8deb62c9b7dd8088a14887dcfdb7448f55202ca 100644
--- a/runtime/vm/object.cc
+++ b/runtime/vm/object.cc
@@ -13477,12 +13477,16 @@ void Code::DisableDartCode() const {
 
 
 void Code::DisableStubCode() const {
+#if !defined(TARGET_ARCH_DBC)
   ASSERT(Thread::Current()->IsMutatorThread());
   ASSERT(IsAllocationStubCode());
   ASSERT(instructions() == active_instructions());
   const Code& new_code =
       Code::Handle(StubCode::FixAllocationStubTarget_entry()->code());
   SetActiveInstructions(new_code.instructions());
+#else
+  UNIMPLEMENTED();

[zra, 2016/04/14 18:27:49]

Will this be implemented, or should this be UNREACHABLE()?

[Vyacheslav Egorov (Google), 2016/04/18 15:56:42]

Done.

+#endif
 }
 
 
@@ -14639,7 +14643,9 @@ bool Instance::IsInstanceOf(const AbstractType& other,
   Zone* zone = Thread::Current()->zone();
   const Class& cls = Class::Handle(zone, clazz());
   if (cls.IsClosureClass()) {
-    if (other.IsObjectType() || other.IsDartFunctionType()) {
+    if (other.IsObjectType() ||
+        other.IsDartFunctionType() ||
+        other.IsDartClosureType()) {

[zra, 2016/04/14 18:27:49]

Is this a pre-existing bug? Should this fix go in its own CL with a test case?

[Vyacheslav Egorov (Google), 2016/04/18 15:56:42]

It's only reproducible/testible on DBC because of how our type-checking is
written. On normal architectures this is handled on fast-path in the assembly
code. 

I discussed with Ivan and he said it's not worth extracting this into a separate
CL. 

       return true;
     }
     Function& other_signature = Function::Handle(zone);
@@ -15409,6 +15415,12 @@ bool AbstractType::IsDartFunctionType() const {
 }
 
 
+bool AbstractType::IsDartClosureType() const {
+  return HasResolvedTypeClass() &&
+      (type_class() == Isolate::Current()->object_store()->closure_class());
+}
+
+
 bool AbstractType::TypeTest(TypeTestKind test_kind,
                             const AbstractType& other,
                             Error* bound_error,