Add Handle/HandleScope and delete SirtRef.

Delete SirtRef and replaced it with Handle. Handles are value types
which wrap around StackReference*.

Renamed StackIndirectReferenceTable to HandleScope.

Added a scoped handle wrapper which wraps around an Object** and
restores it in its destructor.

Renamed Handle::get -> Get.

Bug: 8473721

Change-Id: Idbfebd4f35af629f0f43931b7c5184b334822c7a
diff --git a/compiler/common_compiler_test.h b/compiler/common_compiler_test.h
index 8f39212..586c442 100644
--- a/compiler/common_compiler_test.h
+++ b/compiler/common_compiler_test.h
@@ -257,7 +257,8 @@
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
     std::string class_descriptor(DotToDescriptor(class_name));
     Thread* self = Thread::Current();
-    SirtRef<mirror::ClassLoader> loader(self, class_loader);
+    StackHandleScope<1> hs(self);
+    Handle<mirror::ClassLoader> loader(hs.NewHandle(class_loader));
     mirror::Class* klass = class_linker_->FindClass(self, class_descriptor.c_str(), loader);
     CHECK(klass != nullptr) << "Class not found " << class_name;
     for (size_t i = 0; i < klass->NumDirectMethods(); i++) {
@@ -352,7 +353,8 @@
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
     std::string class_descriptor(DotToDescriptor(class_name));
     Thread* self = Thread::Current();
-    SirtRef<mirror::ClassLoader> loader(self, class_loader);
+    StackHandleScope<1> hs(self);
+    Handle<mirror::ClassLoader> loader(hs.NewHandle(class_loader));
     mirror::Class* klass = class_linker_->FindClass(self, class_descriptor.c_str(), loader);
     CHECK(klass != nullptr) << "Class not found " << class_name;
     for (size_t i = 0; i < klass->NumDirectMethods(); i++) {
@@ -372,7 +374,7 @@
     timings.EndSplit();
   }
 
-  void CompileDirectMethod(SirtRef<mirror::ClassLoader>& class_loader, const char* class_name,
+  void CompileDirectMethod(Handle<mirror::ClassLoader>& class_loader, const char* class_name,
                            const char* method_name, const char* signature)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
     std::string class_descriptor(DotToDescriptor(class_name));
@@ -385,7 +387,7 @@
     CompileMethod(method);
   }
 
-  void CompileVirtualMethod(SirtRef<mirror::ClassLoader>& class_loader, const char* class_name,
+  void CompileVirtualMethod(Handle<mirror::ClassLoader>& class_loader, const char* class_name,
                             const char* method_name, const char* signature)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
     std::string class_descriptor(DotToDescriptor(class_name));
diff --git a/compiler/dex/mir_field_info.cc b/compiler/dex/mir_field_info.cc
index 7c630e8..98866d9 100644
--- a/compiler/dex/mir_field_info.cc
+++ b/compiler/dex/mir_field_info.cc
@@ -21,10 +21,10 @@
 #include "base/logging.h"
 #include "driver/compiler_driver.h"
 #include "driver/compiler_driver-inl.h"
-#include "mirror/class_loader.h"  // Only to allow casts in SirtRef<ClassLoader>.
-#include "mirror/dex_cache.h"     // Only to allow casts in SirtRef<DexCache>.
+#include "mirror/class_loader.h"  // Only to allow casts in Handle<ClassLoader>.
+#include "mirror/dex_cache.h"     // Only to allow casts in Handle<DexCache>.
 #include "scoped_thread_state_change.h"
-#include "sirt_ref-inl.h"
+#include "handle_scope-inl.h"
 
 namespace art {
 
@@ -43,11 +43,12 @@
   // We're going to resolve fields and check access in a tight loop. It's better to hold
   // the lock and needed references once than re-acquiring them again and again.
   ScopedObjectAccess soa(Thread::Current());
-  SirtRef<mirror::DexCache> dex_cache(soa.Self(), compiler_driver->GetDexCache(mUnit));
-  SirtRef<mirror::ClassLoader> class_loader(soa.Self(),
-      compiler_driver->GetClassLoader(soa, mUnit));
-  SirtRef<mirror::Class> referrer_class(soa.Self(),
-      compiler_driver->ResolveCompilingMethodsClass(soa, dex_cache, class_loader, mUnit));
+  StackHandleScope<3> hs(soa.Self());
+  Handle<mirror::DexCache> dex_cache(hs.NewHandle(compiler_driver->GetDexCache(mUnit)));
+  Handle<mirror::ClassLoader> class_loader(
+      hs.NewHandle(compiler_driver->GetClassLoader(soa, mUnit)));
+  Handle<mirror::Class> referrer_class(hs.NewHandle(
+      compiler_driver->ResolveCompilingMethodsClass(soa, dex_cache, class_loader, mUnit)));
   // Even if the referrer class is unresolved (i.e. we're compiling a method without class
   // definition) we still want to resolve fields and record all available info.
 
@@ -63,7 +64,7 @@
     bool is_volatile = compiler_driver->IsFieldVolatile(resolved_field);
 
     std::pair<bool, bool> fast_path = compiler_driver->IsFastInstanceField(
-        dex_cache.get(), referrer_class.get(), resolved_field, field_idx, &it->field_offset_);
+        dex_cache.Get(), referrer_class.Get(), resolved_field, field_idx, &it->field_offset_);
     it->flags_ = 0u |  // Without kFlagIsStatic.
         (is_volatile ? kFlagIsVolatile : 0u) |
         (fast_path.first ? kFlagFastGet : 0u) |
@@ -89,11 +90,12 @@
   // We're going to resolve fields and check access in a tight loop. It's better to hold
   // the lock and needed references once than re-acquiring them again and again.
   ScopedObjectAccess soa(Thread::Current());
-  SirtRef<mirror::DexCache> dex_cache(soa.Self(), compiler_driver->GetDexCache(mUnit));
-  SirtRef<mirror::ClassLoader> class_loader(soa.Self(),
-      compiler_driver->GetClassLoader(soa, mUnit));
-  SirtRef<mirror::Class> referrer_class(soa.Self(),
-      compiler_driver->ResolveCompilingMethodsClass(soa, dex_cache, class_loader, mUnit));
+  StackHandleScope<3> hs(soa.Self());
+  Handle<mirror::DexCache> dex_cache(hs.NewHandle(compiler_driver->GetDexCache(mUnit)));
+  Handle<mirror::ClassLoader> class_loader(
+      hs.NewHandle(compiler_driver->GetClassLoader(soa, mUnit)));
+  Handle<mirror::Class> referrer_class(hs.NewHandle(
+      compiler_driver->ResolveCompilingMethodsClass(soa, dex_cache, class_loader, mUnit)));
   // Even if the referrer class is unresolved (i.e. we're compiling a method without class
   // definition) we still want to resolve fields and record all available info.
 
@@ -110,7 +112,7 @@
 
     bool is_referrers_class, is_initialized;
     std::pair<bool, bool> fast_path = compiler_driver->IsFastStaticField(
-        dex_cache.get(), referrer_class.get(), resolved_field, field_idx, &it->field_offset_,
+        dex_cache.Get(), referrer_class.Get(), resolved_field, field_idx, &it->field_offset_,
         &it->storage_index_, &is_referrers_class, &is_initialized);
     it->flags_ = kFlagIsStatic |
         (is_volatile ? kFlagIsVolatile : 0u) |
diff --git a/compiler/dex/mir_method_info.cc b/compiler/dex/mir_method_info.cc
index 2c33ef1..cc2bd95 100644
--- a/compiler/dex/mir_method_info.cc
+++ b/compiler/dex/mir_method_info.cc
@@ -19,10 +19,10 @@
 #include "driver/compiler_driver.h"
 #include "driver/dex_compilation_unit.h"
 #include "driver/compiler_driver-inl.h"
-#include "mirror/class_loader.h"  // Only to allow casts in SirtRef<ClassLoader>.
-#include "mirror/dex_cache.h"     // Only to allow casts in SirtRef<DexCache>.
+#include "mirror/class_loader.h"  // Only to allow casts in Handle<ClassLoader>.
+#include "mirror/dex_cache.h"     // Only to allow casts in Handle<DexCache>.
 #include "scoped_thread_state_change.h"
-#include "sirt_ref.h"
+#include "handle_scope-inl.h"
 
 namespace art {
 
@@ -45,11 +45,12 @@
   // We're going to resolve methods and check access in a tight loop. It's better to hold
   // the lock and needed references once than re-acquiring them again and again.
   ScopedObjectAccess soa(Thread::Current());
-  SirtRef<mirror::DexCache> dex_cache(soa.Self(), compiler_driver->GetDexCache(mUnit));
-  SirtRef<mirror::ClassLoader> class_loader(soa.Self(),
-      compiler_driver->GetClassLoader(soa, mUnit));
-  SirtRef<mirror::Class> referrer_class(soa.Self(),
-      compiler_driver->ResolveCompilingMethodsClass(soa, dex_cache, class_loader, mUnit));
+  StackHandleScope<3> hs(soa.Self());
+  Handle<mirror::DexCache> dex_cache(hs.NewHandle(compiler_driver->GetDexCache(mUnit)));
+  Handle<mirror::ClassLoader> class_loader(
+      hs.NewHandle(compiler_driver->GetClassLoader(soa, mUnit)));
+  Handle<mirror::Class> referrer_class(hs.NewHandle(
+      compiler_driver->ResolveCompilingMethodsClass(soa, dex_cache, class_loader, mUnit)));
   // Even if the referrer class is unresolved (i.e. we're compiling a method without class
   // definition) we still want to resolve methods and record all available info.
 
@@ -73,10 +74,10 @@
 
     MethodReference target_method(mUnit->GetDexFile(), it->MethodIndex());
     int fast_path_flags = compiler_driver->IsFastInvoke(
-        soa, dex_cache, class_loader, mUnit, referrer_class.get(), resolved_method, &invoke_type,
+        soa, dex_cache, class_loader, mUnit, referrer_class.Get(), resolved_method, &invoke_type,
         &target_method, devirt_target, &it->direct_code_, &it->direct_method_);
     bool needs_clinit =
-        compiler_driver->NeedsClassInitialization(referrer_class.get(), resolved_method);
+        compiler_driver->NeedsClassInitialization(referrer_class.Get(), resolved_method);
     uint16_t other_flags = it->flags_ &
         ~(kFlagFastPath | kFlagNeedsClassInitialization | (kInvokeTypeMask << kBitSharpTypeBegin));
     it->flags_ = other_flags |
diff --git a/compiler/driver/compiler_driver-inl.h b/compiler/driver/compiler_driver-inl.h
index d9f2a3a..08fd386 100644
--- a/compiler/driver/compiler_driver-inl.h
+++ b/compiler/driver/compiler_driver-inl.h
@@ -28,7 +28,7 @@
 #include "mirror/dex_cache-inl.h"
 #include "mirror/art_field-inl.h"
 #include "scoped_thread_state_change.h"
-#include "sirt_ref-inl.h"
+#include "handle_scope-inl.h"
 
 namespace art {
 
@@ -42,10 +42,10 @@
 }
 
 inline mirror::Class* CompilerDriver::ResolveCompilingMethodsClass(
-    ScopedObjectAccess& soa, const SirtRef<mirror::DexCache>& dex_cache,
-    const SirtRef<mirror::ClassLoader>& class_loader, const DexCompilationUnit* mUnit) {
-  DCHECK(dex_cache->GetDexFile() == mUnit->GetDexFile());
-  DCHECK(class_loader.get() == soa.Decode<mirror::ClassLoader*>(mUnit->GetClassLoader()));
+    ScopedObjectAccess& soa, const Handle<mirror::DexCache>& dex_cache,
+    const Handle<mirror::ClassLoader>& class_loader, const DexCompilationUnit* mUnit) {
+  DCHECK_EQ(dex_cache->GetDexFile(), mUnit->GetDexFile());
+  DCHECK_EQ(class_loader.Get(), soa.Decode<mirror::ClassLoader*>(mUnit->GetClassLoader()));
   const DexFile::MethodId& referrer_method_id =
       mUnit->GetDexFile()->GetMethodId(mUnit->GetDexMethodIndex());
   mirror::Class* referrer_class = mUnit->GetClassLinker()->ResolveType(
@@ -59,11 +59,11 @@
 }
 
 inline mirror::ArtField* CompilerDriver::ResolveField(
-    ScopedObjectAccess& soa, const SirtRef<mirror::DexCache>& dex_cache,
-    const SirtRef<mirror::ClassLoader>& class_loader, const DexCompilationUnit* mUnit,
+    ScopedObjectAccess& soa, const Handle<mirror::DexCache>& dex_cache,
+    const Handle<mirror::ClassLoader>& class_loader, const DexCompilationUnit* mUnit,
     uint32_t field_idx, bool is_static) {
-  DCHECK(dex_cache->GetDexFile() == mUnit->GetDexFile());
-  DCHECK(class_loader.get() == soa.Decode<mirror::ClassLoader*>(mUnit->GetClassLoader()));
+  DCHECK_EQ(dex_cache->GetDexFile(), mUnit->GetDexFile());
+  DCHECK_EQ(class_loader.Get(), soa.Decode<mirror::ClassLoader*>(mUnit->GetClassLoader()));
   mirror::ArtField* resolved_field = mUnit->GetClassLinker()->ResolveField(
       *mUnit->GetDexFile(), field_idx, dex_cache, class_loader, is_static);
   DCHECK_EQ(resolved_field == nullptr, soa.Self()->IsExceptionPending());
@@ -165,11 +165,11 @@
 }
 
 inline mirror::ArtMethod* CompilerDriver::ResolveMethod(
-    ScopedObjectAccess& soa, const SirtRef<mirror::DexCache>& dex_cache,
-    const SirtRef<mirror::ClassLoader>& class_loader, const DexCompilationUnit* mUnit,
+    ScopedObjectAccess& soa, const Handle<mirror::DexCache>& dex_cache,
+    const Handle<mirror::ClassLoader>& class_loader, const DexCompilationUnit* mUnit,
     uint32_t method_idx, InvokeType invoke_type) {
   DCHECK(dex_cache->GetDexFile() == mUnit->GetDexFile());
-  DCHECK(class_loader.get() == soa.Decode<mirror::ClassLoader*>(mUnit->GetClassLoader()));
+  DCHECK(class_loader.Get() == soa.Decode<mirror::ClassLoader*>(mUnit->GetClassLoader()));
   mirror::ArtMethod* resolved_method = mUnit->GetClassLinker()->ResolveMethod(
       *mUnit->GetDexFile(), method_idx, dex_cache, class_loader, nullptr, invoke_type);
   DCHECK_EQ(resolved_method == nullptr, soa.Self()->IsExceptionPending());
@@ -206,8 +206,8 @@
 }
 
 inline int CompilerDriver::IsFastInvoke(
-    ScopedObjectAccess& soa, const SirtRef<mirror::DexCache>& dex_cache,
-    const SirtRef<mirror::ClassLoader>& class_loader, const DexCompilationUnit* mUnit,
+    ScopedObjectAccess& soa, const Handle<mirror::DexCache>& dex_cache,
+    const Handle<mirror::ClassLoader>& class_loader, const DexCompilationUnit* mUnit,
     mirror::Class* referrer_class, mirror::ArtMethod* resolved_method, InvokeType* invoke_type,
     MethodReference* target_method, const MethodReference* devirt_target,
     uintptr_t* direct_code, uintptr_t* direct_method) {
@@ -217,7 +217,7 @@
   }
   mirror::Class* methods_class = resolved_method->GetDeclaringClass();
   if (UNLIKELY(!referrer_class->CanAccessResolvedMethod(methods_class, resolved_method,
-                                                        dex_cache.get(),
+                                                        dex_cache.Get(),
                                                         target_method->dex_method_index))) {
     return 0;
   }
@@ -237,7 +237,7 @@
     // Sharpen a virtual call into a direct call. The method_idx is into referrer's
     // dex cache, check that this resolved method is where we expect it.
     CHECK(target_method->dex_file == mUnit->GetDexFile());
-    DCHECK(dex_cache.get() == mUnit->GetClassLinker()->FindDexCache(*mUnit->GetDexFile()));
+    DCHECK(dex_cache.Get() == mUnit->GetClassLinker()->FindDexCache(*mUnit->GetDexFile()));
     CHECK(referrer_class->GetDexCache()->GetResolvedMethod(target_method->dex_method_index) ==
         resolved_method) << PrettyMethod(resolved_method);
     int stats_flags = kFlagMethodResolved;
@@ -259,8 +259,9 @@
                                                   devirt_target->dex_method_index,
                                                   dex_cache, class_loader, NULL, kVirtual);
     } else {
-      SirtRef<mirror::DexCache> target_dex_cache(soa.Self(),
-          class_linker->FindDexCache(*devirt_target->dex_file));
+      StackHandleScope<1> hs(soa.Self());
+      Handle<mirror::DexCache> target_dex_cache(
+          hs.NewHandle(class_linker->FindDexCache(*devirt_target->dex_file)));
       called_method = class_linker->ResolveMethod(*devirt_target->dex_file,
                                                   devirt_target->dex_method_index,
                                                   target_dex_cache, class_loader, NULL, kVirtual);
diff --git a/compiler/driver/compiler_driver.cc b/compiler/driver/compiler_driver.cc
index 6817f14..547b9f7 100644
--- a/compiler/driver/compiler_driver.cc
+++ b/compiler/driver/compiler_driver.cc
@@ -49,7 +49,7 @@
 #include "mirror/throwable.h"
 #include "scoped_thread_state_change.h"
 #include "ScopedLocalRef.h"
-#include "sirt_ref-inl.h"
+#include "handle_scope-inl.h"
 #include "thread.h"
 #include "thread_pool.h"
 #include "trampolines/trampoline_compiler.h"
@@ -509,7 +509,7 @@
 }
 
 static DexToDexCompilationLevel GetDexToDexCompilationlevel(
-    Thread* self, SirtRef<mirror::ClassLoader>& class_loader, const DexFile& dex_file,
+    Thread* self, Handle<mirror::ClassLoader>& class_loader, const DexFile& dex_file,
     const DexFile::ClassDef& class_def) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
   const char* descriptor = dex_file.GetClassDescriptor(class_def);
   ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
@@ -524,7 +524,7 @@
   // function). Since image classes can be verified again while compiling an application,
   // we must prevent the DEX-to-DEX compiler from introducing them.
   // TODO: find a way to enable "quick" instructions for image classes and remove this check.
-  bool compiling_image_classes = class_loader.get() == nullptr;
+  bool compiling_image_classes = class_loader.Get() == nullptr;
   if (compiling_image_classes) {
     return kRequired;
   } else if (klass->IsVerified()) {
@@ -574,8 +574,9 @@
   {
     ScopedObjectAccess soa(Thread::Current());
     const DexFile::ClassDef& class_def = dex_file->GetClassDef(class_def_idx);
-    SirtRef<mirror::ClassLoader> class_loader(soa.Self(),
-                                              soa.Decode<mirror::ClassLoader*>(jclass_loader));
+    StackHandleScope<1> hs(soa.Self());
+    Handle<mirror::ClassLoader> class_loader(
+        hs.NewHandle(soa.Decode<mirror::ClassLoader*>(jclass_loader)));
     dex_to_dex_compilation_level = GetDexToDexCompilationlevel(self, class_loader, *dex_file,
                                                                class_def);
   }
@@ -700,8 +701,10 @@
   ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
   for (auto it = image_classes_->begin(), end = image_classes_->end(); it != end;) {
     const std::string& descriptor(*it);
-    SirtRef<mirror::Class> klass(self, class_linker->FindSystemClass(self, descriptor.c_str()));
-    if (klass.get() == NULL) {
+    StackHandleScope<1> hs(self);
+    Handle<mirror::Class> klass(
+        hs.NewHandle(class_linker->FindSystemClass(self, descriptor.c_str())));
+    if (klass.Get() == NULL) {
       VLOG(compiler) << "Failed to find class " << descriptor;
       image_classes_->erase(it++);
       self->ClearException();
@@ -714,8 +717,9 @@
   // exceptions are resolved by the verifier when there is a catch block in an interested method.
   // Do this here so that exception classes appear to have been specified image classes.
   std::set<std::pair<uint16_t, const DexFile*> > unresolved_exception_types;
-  SirtRef<mirror::Class> java_lang_Throwable(self,
-                                     class_linker->FindSystemClass(self, "Ljava/lang/Throwable;"));
+  StackHandleScope<1> hs(self);
+  Handle<mirror::Class> java_lang_Throwable(
+      hs.NewHandle(class_linker->FindSystemClass(self, "Ljava/lang/Throwable;")));
   do {
     unresolved_exception_types.clear();
     class_linker->VisitClasses(ResolveCatchBlockExceptionsClassVisitor,
@@ -723,16 +727,17 @@
     for (const std::pair<uint16_t, const DexFile*>& exception_type : unresolved_exception_types) {
       uint16_t exception_type_idx = exception_type.first;
       const DexFile* dex_file = exception_type.second;
-      SirtRef<mirror::DexCache> dex_cache(self, class_linker->FindDexCache(*dex_file));
-      SirtRef<mirror::ClassLoader> class_loader(self, nullptr);
-      SirtRef<mirror::Class> klass(self, class_linker->ResolveType(*dex_file, exception_type_idx,
-                                                                   dex_cache, class_loader));
-      if (klass.get() == NULL) {
+      StackHandleScope<3> hs(self);
+      Handle<mirror::DexCache> dex_cache(hs.NewHandle(class_linker->FindDexCache(*dex_file)));
+      auto class_loader(hs.NewHandle<mirror::ClassLoader>(nullptr));
+      Handle<mirror::Class> klass(hs.NewHandle(
+          class_linker->ResolveType(*dex_file, exception_type_idx, dex_cache, class_loader)));
+      if (klass.Get() == NULL) {
         const DexFile::TypeId& type_id = dex_file->GetTypeId(exception_type_idx);
         const char* descriptor = dex_file->GetTypeDescriptor(type_id);
         LOG(FATAL) << "Failed to resolve class " << descriptor;
       }
-      DCHECK(java_lang_Throwable->IsAssignableFrom(klass.get()));
+      DCHECK(java_lang_Throwable->IsAssignableFrom(klass.Get()));
     }
     // Resolving exceptions may load classes that reference more exceptions, iterate until no
     // more are found
@@ -816,7 +821,9 @@
   if (IsImage()) {
     // We resolve all const-string strings when building for the image.
     ScopedObjectAccess soa(Thread::Current());
-    SirtRef<mirror::DexCache> dex_cache(soa.Self(), Runtime::Current()->GetClassLinker()->FindDexCache(dex_file));
+    StackHandleScope<1> hs(soa.Self());
+    Handle<mirror::DexCache> dex_cache(
+        hs.NewHandle(Runtime::Current()->GetClassLinker()->FindDexCache(dex_file)));
     Runtime::Current()->GetClassLinker()->ResolveString(dex_file, string_idx, dex_cache);
     result = true;
   }
@@ -980,16 +987,17 @@
   mirror::Class* referrer_class;
   mirror::DexCache* dex_cache;
   {
-    SirtRef<mirror::DexCache> dex_cache_sirt(soa.Self(),
-        mUnit->GetClassLinker()->FindDexCache(*mUnit->GetDexFile()));
-    SirtRef<mirror::ClassLoader> class_loader_sirt(soa.Self(),
-        soa.Decode<mirror::ClassLoader*>(mUnit->GetClassLoader()));
-    SirtRef<mirror::ArtField> resolved_field_sirt(soa.Self(),
-        ResolveField(soa, dex_cache_sirt, class_loader_sirt, mUnit, field_idx, false));
-    referrer_class = (resolved_field_sirt.get() != nullptr)
-        ? ResolveCompilingMethodsClass(soa, dex_cache_sirt, class_loader_sirt, mUnit) : nullptr;
-    resolved_field = resolved_field_sirt.get();
-    dex_cache = dex_cache_sirt.get();
+    StackHandleScope<3> hs(soa.Self());
+    Handle<mirror::DexCache> dex_cache_handle(
+        hs.NewHandle(mUnit->GetClassLinker()->FindDexCache(*mUnit->GetDexFile())));
+    Handle<mirror::ClassLoader> class_loader_handle(
+        hs.NewHandle(soa.Decode<mirror::ClassLoader*>(mUnit->GetClassLoader())));
+    Handle<mirror::ArtField> resolved_field_handle(hs.NewHandle(
+        ResolveField(soa, dex_cache_handle, class_loader_handle, mUnit, field_idx, false)));
+    referrer_class = (resolved_field_handle.Get() != nullptr)
+        ? ResolveCompilingMethodsClass(soa, dex_cache_handle, class_loader_handle, mUnit) : nullptr;
+    resolved_field = resolved_field_handle.Get();
+    dex_cache = dex_cache_handle.Get();
   }
   bool result = false;
   if (resolved_field != nullptr && referrer_class != nullptr) {
@@ -1017,16 +1025,17 @@
   mirror::Class* referrer_class;
   mirror::DexCache* dex_cache;
   {
-    SirtRef<mirror::DexCache> dex_cache_sirt(soa.Self(),
-        mUnit->GetClassLinker()->FindDexCache(*mUnit->GetDexFile()));
-    SirtRef<mirror::ClassLoader> class_loader_sirt(soa.Self(),
-        soa.Decode<mirror::ClassLoader*>(mUnit->GetClassLoader()));
-    SirtRef<mirror::ArtField> resolved_field_sirt(soa.Self(),
-        ResolveField(soa, dex_cache_sirt, class_loader_sirt, mUnit, field_idx, true));
-    referrer_class = (resolved_field_sirt.get() != nullptr)
-        ? ResolveCompilingMethodsClass(soa, dex_cache_sirt, class_loader_sirt, mUnit) : nullptr;
-    resolved_field = resolved_field_sirt.get();
-    dex_cache = dex_cache_sirt.get();
+    StackHandleScope<3> hs(soa.Self());
+    Handle<mirror::DexCache> dex_cache_handle(
+        hs.NewHandle(mUnit->GetClassLinker()->FindDexCache(*mUnit->GetDexFile())));
+    Handle<mirror::ClassLoader> class_loader_handle(
+        hs.NewHandle(soa.Decode<mirror::ClassLoader*>(mUnit->GetClassLoader())));
+    Handle<mirror::ArtField> resolved_field_handle(hs.NewHandle(
+        ResolveField(soa, dex_cache_handle, class_loader_handle, mUnit, field_idx, true)));
+    referrer_class = (resolved_field_handle.Get() != nullptr)
+        ? ResolveCompilingMethodsClass(soa, dex_cache_handle, class_loader_handle, mUnit) : nullptr;
+    resolved_field = resolved_field_handle.Get();
+    dex_cache = dex_cache_handle.Get();
   }
   bool result = false;
   if (resolved_field != nullptr && referrer_class != nullptr) {
@@ -1168,17 +1177,18 @@
   // Try to resolve the method and compiling method's class.
   mirror::ArtMethod* resolved_method;
   mirror::Class* referrer_class;
-  SirtRef<mirror::DexCache> dex_cache(soa.Self(),
-      mUnit->GetClassLinker()->FindDexCache(*mUnit->GetDexFile()));
-  SirtRef<mirror::ClassLoader> class_loader(soa.Self(),
-      soa.Decode<mirror::ClassLoader*>(mUnit->GetClassLoader()));
+  StackHandleScope<3> hs(soa.Self());
+  Handle<mirror::DexCache> dex_cache(
+      hs.NewHandle(mUnit->GetClassLinker()->FindDexCache(*mUnit->GetDexFile())));
+  Handle<mirror::ClassLoader> class_loader(hs.NewHandle(
+      soa.Decode<mirror::ClassLoader*>(mUnit->GetClassLoader())));
   {
     uint32_t method_idx = target_method->dex_method_index;
-    SirtRef<mirror::ArtMethod> resolved_method_sirt(soa.Self(),
-        ResolveMethod(soa, dex_cache, class_loader, mUnit, method_idx, orig_invoke_type));
-    referrer_class = (resolved_method_sirt.get() != nullptr)
+    Handle<mirror::ArtMethod> resolved_method_handle(hs.NewHandle(
+        ResolveMethod(soa, dex_cache, class_loader, mUnit, method_idx, orig_invoke_type)));
+    referrer_class = (resolved_method_handle.Get() != nullptr)
         ? ResolveCompilingMethodsClass(soa, dex_cache, class_loader, mUnit) : nullptr;
-    resolved_method = resolved_method_sirt.get();
+    resolved_method = resolved_method_handle.Get();
   }
   bool result = false;
   if (resolved_method != nullptr) {
@@ -1196,7 +1206,7 @@
       // Devirtualization not enabled. Inline IsFastInvoke(), dropping the devirtualization parts.
       if (UNLIKELY(referrer_class == nullptr) ||
           UNLIKELY(!referrer_class->CanAccessResolvedMethod(resolved_method->GetDeclaringClass(),
-                                                            resolved_method, dex_cache.get(),
+                                                            resolved_method, dex_cache.Get(),
                                                             target_method->dex_method_index)) ||
           *invoke_type == kSuper) {
         // Slow path. (Without devirtualization, all super calls go slow path as well.)
@@ -1469,8 +1479,10 @@
   const DexFile::ClassDef& class_def = dex_file.GetClassDef(class_def_index);
   if (!SkipClass(class_linker, jclass_loader, dex_file, class_def)) {
     ScopedObjectAccess soa(self);
-    SirtRef<mirror::ClassLoader> class_loader(soa.Self(), soa.Decode<mirror::ClassLoader*>(jclass_loader));
-    SirtRef<mirror::DexCache> dex_cache(soa.Self(), class_linker->FindDexCache(dex_file));
+    StackHandleScope<2> hs(soa.Self());
+    Handle<mirror::ClassLoader> class_loader(
+        hs.NewHandle(soa.Decode<mirror::ClassLoader*>(jclass_loader)));
+    Handle<mirror::DexCache> dex_cache(hs.NewHandle(class_linker->FindDexCache(dex_file)));
     // Resolve the class.
     mirror::Class* klass = class_linker->ResolveType(dex_file, class_def.class_idx_, dex_cache,
                                                      class_loader);
@@ -1556,9 +1568,10 @@
   ScopedObjectAccess soa(Thread::Current());
   ClassLinker* class_linker = manager->GetClassLinker();
   const DexFile& dex_file = *manager->GetDexFile();
-  SirtRef<mirror::DexCache> dex_cache(soa.Self(), class_linker->FindDexCache(dex_file));
-  SirtRef<mirror::ClassLoader> class_loader(
-      soa.Self(), soa.Decode<mirror::ClassLoader*>(manager->GetClassLoader()));
+  StackHandleScope<2> hs(soa.Self());
+  Handle<mirror::DexCache> dex_cache(hs.NewHandle(class_linker->FindDexCache(dex_file)));
+  Handle<mirror::ClassLoader> class_loader(
+      hs.NewHandle(soa.Decode<mirror::ClassLoader*>(manager->GetClassLoader())));
   mirror::Class* klass = class_linker->ResolveType(dex_file, type_idx, dex_cache, class_loader);
 
   if (klass == NULL) {
@@ -1611,11 +1624,12 @@
   const char* descriptor = dex_file.GetClassDescriptor(class_def);
   ClassLinker* class_linker = manager->GetClassLinker();
   jobject jclass_loader = manager->GetClassLoader();
-  SirtRef<mirror::ClassLoader> class_loader(
-      soa.Self(), soa.Decode<mirror::ClassLoader*>(jclass_loader));
-  SirtRef<mirror::Class> klass(soa.Self(), class_linker->FindClass(soa.Self(), descriptor,
-                                                                   class_loader));
-  if (klass.get() == nullptr) {
+  StackHandleScope<3> hs(soa.Self());
+  Handle<mirror::ClassLoader> class_loader(
+      hs.NewHandle(soa.Decode<mirror::ClassLoader*>(jclass_loader)));
+  Handle<mirror::Class> klass(
+      hs.NewHandle(class_linker->FindClass(soa.Self(), descriptor, class_loader)));
+  if (klass.Get() == nullptr) {
     CHECK(soa.Self()->IsExceptionPending());
     soa.Self()->ClearException();
 
@@ -1624,7 +1638,7 @@
      * This is to ensure the class is structurally sound for compilation. An unsound class
      * will be rejected by the verifier and later skipped during compilation in the compiler.
      */
-    SirtRef<mirror::DexCache> dex_cache(soa.Self(), class_linker->FindDexCache(dex_file));
+    Handle<mirror::DexCache> dex_cache(hs.NewHandle(class_linker->FindDexCache(dex_file)));
     std::string error_msg;
     if (verifier::MethodVerifier::VerifyClass(&dex_file, dex_cache, class_loader, &class_def, true,
                                               &error_msg) ==
@@ -1632,8 +1646,8 @@
       LOG(ERROR) << "Verification failed on class " << PrettyDescriptor(descriptor)
                  << " because: " << error_msg;
     }
-  } else if (!SkipClass(jclass_loader, dex_file, klass.get())) {
-    CHECK(klass->IsResolved()) << PrettyClass(klass.get());
+  } else if (!SkipClass(jclass_loader, dex_file, klass.Get())) {
+    CHECK(klass->IsResolved()) << PrettyClass(klass.Get());
     class_linker->VerifyClass(klass);
 
     if (klass->IsErroneous()) {
@@ -1643,7 +1657,7 @@
     }
 
     CHECK(klass->IsCompileTimeVerified() || klass->IsErroneous())
-        << PrettyDescriptor(klass.get()) << ": state=" << klass->GetStatus();
+        << PrettyDescriptor(klass.Get()) << ": state=" << klass->GetStatus();
   }
   soa.Self()->AssertNoPendingException();
 }
@@ -1666,13 +1680,13 @@
   const char* descriptor = dex_file.StringDataByIdx(class_type_id.descriptor_idx_);
 
   ScopedObjectAccess soa(Thread::Current());
-  SirtRef<mirror::ClassLoader> class_loader(soa.Self(),
-                                            soa.Decode<mirror::ClassLoader*>(jclass_loader));
-  SirtRef<mirror::Class> klass(soa.Self(),
-                               manager->GetClassLinker()->FindClass(soa.Self(), descriptor,
-                                                                    class_loader));
+  StackHandleScope<3> hs(soa.Self());
+  Handle<mirror::ClassLoader> class_loader(
+      hs.NewHandle(soa.Decode<mirror::ClassLoader*>(jclass_loader)));
+  Handle<mirror::Class> klass(
+      hs.NewHandle(manager->GetClassLinker()->FindClass(soa.Self(), descriptor, class_loader)));
 
-  if (klass.get() != nullptr && !SkipClass(jclass_loader, dex_file, klass.get())) {
+  if (klass.Get() != nullptr && !SkipClass(jclass_loader, dex_file, klass.Get())) {
     // Only try to initialize classes that were successfully verified.
     if (klass->IsVerified()) {
       // Attempt to initialize the class but bail if we either need to initialize the super-class
@@ -1687,8 +1701,8 @@
         // parent-to-child and a child-to-parent lock ordering and consequent potential deadlock.
         // We need to use an ObjectLock due to potential suspension in the interpreting code. Rather
         // than use a special Object for the purpose we use the Class of java.lang.Class.
-        SirtRef<mirror::Class> sirt_klass(soa.Self(), klass->GetClass());
-        ObjectLock<mirror::Class> lock(soa.Self(), &sirt_klass);
+        Handle<mirror::Class> h_klass(hs.NewHandle(klass->GetClass()));
+        ObjectLock<mirror::Class> lock(soa.Self(), &h_klass);
         // Attempt to initialize allowing initialization of parent classes but still not static
         // fields.
         manager->GetClassLinker()->EnsureInitialized(klass, false, true);
@@ -1803,8 +1817,9 @@
   DexToDexCompilationLevel dex_to_dex_compilation_level = kDontDexToDexCompile;
   {
     ScopedObjectAccess soa(Thread::Current());
-    SirtRef<mirror::ClassLoader> class_loader(soa.Self(),
-                                              soa.Decode<mirror::ClassLoader*>(jclass_loader));
+    StackHandleScope<1> hs(soa.Self());
+    Handle<mirror::ClassLoader> class_loader(
+        hs.NewHandle(soa.Decode<mirror::ClassLoader*>(jclass_loader)));
     dex_to_dex_compilation_level = GetDexToDexCompilationlevel(soa.Self(), class_loader, dex_file,
                                                                class_def);
   }
diff --git a/compiler/driver/compiler_driver.h b/compiler/driver/compiler_driver.h
index 6ac9cf7..f3db41f 100644
--- a/compiler/driver/compiler_driver.h
+++ b/compiler/driver/compiler_driver.h
@@ -52,7 +52,7 @@
 class OatWriter;
 class ParallelCompilationManager;
 class ScopedObjectAccess;
-template<class T> class SirtRef;
+template<class T> class Handle;
 class TimingLogger;
 class VerificationResults;
 class VerifiedMethod;
@@ -221,15 +221,15 @@
 
   // Resolve compiling method's class. Returns nullptr on failure.
   mirror::Class* ResolveCompilingMethodsClass(
-      ScopedObjectAccess& soa, const SirtRef<mirror::DexCache>& dex_cache,
-      const SirtRef<mirror::ClassLoader>& class_loader, const DexCompilationUnit* mUnit)
+      ScopedObjectAccess& soa, const Handle<mirror::DexCache>& dex_cache,
+      const Handle<mirror::ClassLoader>& class_loader, const DexCompilationUnit* mUnit)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
   // Resolve a field. Returns nullptr on failure, including incompatible class change.
   // NOTE: Unlike ClassLinker's ResolveField(), this method enforces is_static.
   mirror::ArtField* ResolveField(
-      ScopedObjectAccess& soa, const SirtRef<mirror::DexCache>& dex_cache,
-      const SirtRef<mirror::ClassLoader>& class_loader, const DexCompilationUnit* mUnit,
+      ScopedObjectAccess& soa, const Handle<mirror::DexCache>& dex_cache,
+      const Handle<mirror::ClassLoader>& class_loader, const DexCompilationUnit* mUnit,
       uint32_t field_idx, bool is_static)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
@@ -258,8 +258,8 @@
 
   // Resolve a method. Returns nullptr on failure, including incompatible class change.
   mirror::ArtMethod* ResolveMethod(
-      ScopedObjectAccess& soa, const SirtRef<mirror::DexCache>& dex_cache,
-      const SirtRef<mirror::ClassLoader>& class_loader, const DexCompilationUnit* mUnit,
+      ScopedObjectAccess& soa, const Handle<mirror::DexCache>& dex_cache,
+      const Handle<mirror::ClassLoader>& class_loader, const DexCompilationUnit* mUnit,
       uint32_t method_idx, InvokeType invoke_type)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
@@ -277,8 +277,8 @@
   // Can we fast-path an INVOKE? If no, returns 0. If yes, returns a non-zero opaque flags value
   // for ProcessedInvoke() and computes the necessary lowering info.
   int IsFastInvoke(
-      ScopedObjectAccess& soa, const SirtRef<mirror::DexCache>& dex_cache,
-      const SirtRef<mirror::ClassLoader>& class_loader, const DexCompilationUnit* mUnit,
+      ScopedObjectAccess& soa, const Handle<mirror::DexCache>& dex_cache,
+      const Handle<mirror::ClassLoader>& class_loader, const DexCompilationUnit* mUnit,
       mirror::Class* referrer_class, mirror::ArtMethod* resolved_method, InvokeType* invoke_type,
       MethodReference* target_method, const MethodReference* devirt_target,
       uintptr_t* direct_code, uintptr_t* direct_method)
diff --git a/compiler/driver/compiler_driver_test.cc b/compiler/driver/compiler_driver_test.cc
index 86034c8..113594a 100644
--- a/compiler/driver/compiler_driver_test.cc
+++ b/compiler/driver/compiler_driver_test.cc
@@ -30,7 +30,7 @@
 #include "mirror/dex_cache-inl.h"
 #include "mirror/object_array-inl.h"
 #include "mirror/object-inl.h"
-#include "sirt_ref-inl.h"
+#include "handle_scope-inl.h"
 
 namespace art {
 
@@ -80,7 +80,9 @@
       const DexFile::ClassDef& class_def = dex_file.GetClassDef(i);
       const char* descriptor = dex_file.GetClassDescriptor(class_def);
       ScopedObjectAccess soa(Thread::Current());
-      SirtRef<mirror::ClassLoader> loader(soa.Self(), soa.Decode<mirror::ClassLoader*>(class_loader));
+      StackHandleScope<1> hs(soa.Self());
+      Handle<mirror::ClassLoader> loader(
+          hs.NewHandle(soa.Decode<mirror::ClassLoader*>(class_loader)));
       mirror::Class* c = class_linker->FindClass(soa.Self(), descriptor, loader);
       CHECK(c != NULL);
       for (size_t i = 0; i < c->NumDirectMethods(); i++) {
@@ -150,7 +152,8 @@
   jobject class_loader;
   {
     ScopedObjectAccess soa(Thread::Current());
-    SirtRef<mirror::ClassLoader> null_loader(soa.Self(), nullptr);
+    StackHandleScope<1> hs(soa.Self());
+    auto null_loader(hs.NewHandle<mirror::ClassLoader>(nullptr));
     CompileVirtualMethod(null_loader, "java.lang.Class", "isFinalizable", "()Z");
     CompileDirectMethod(null_loader, "java.lang.Object", "<init>", "()V");
     class_loader = LoadDex("AbstractMethod");
diff --git a/compiler/elf_writer_mclinker.cc b/compiler/elf_writer_mclinker.cc
index f688103..eb9b230 100644
--- a/compiler/elf_writer_mclinker.cc
+++ b/compiler/elf_writer_mclinker.cc
@@ -361,8 +361,8 @@
       ClassLinker* linker = Runtime::Current()->GetClassLinker();
       // Unchecked as we hold mutator_lock_ on entry.
       ScopedObjectAccessUnchecked soa(Thread::Current());
-      SirtRef<mirror::DexCache> dex_cache(soa.Self(), linker->FindDexCache(dex_file));
-      SirtRef<mirror::ClassLoader> class_loader(soa.Self(), nullptr);
+      Handle<mirror::DexCache> dex_cache(soa.Self(), linker->FindDexCache(dex_file));
+      Handle<mirror::ClassLoader> class_loader(soa.Self(), nullptr);
       method = linker->ResolveMethod(dex_file, method_idx, dex_cache, class_loader, NULL, invoke_type);
       CHECK(method != NULL);
     }
diff --git a/compiler/image_writer.cc b/compiler/image_writer.cc
index 62817e7..d855eee 100644
--- a/compiler/image_writer.cc
+++ b/compiler/image_writer.cc
@@ -51,7 +51,7 @@
 #include "object_utils.h"
 #include "runtime.h"
 #include "scoped_thread_state_change.h"
-#include "sirt_ref-inl.h"
+#include "handle_scope-inl.h"
 #include "UniquePtr.h"
 #include "utils.h"
 
@@ -382,16 +382,14 @@
       DCHECK_EQ(obj, obj->AsString()->Intern());
       return;
     }
-    Thread* self = Thread::Current();
-    SirtRef<Object> sirt_obj(self, obj);
-    mirror::String* interned = obj->AsString()->Intern();
-    if (sirt_obj.get() != interned) {
+    mirror::String* const interned = obj->AsString()->Intern();
+    if (obj != interned) {
       if (!IsImageOffsetAssigned(interned)) {
         // interned obj is after us, allocate its location early
         AssignImageOffset(interned);
       }
       // point those looking for this object to the interned version.
-      SetImageOffset(sirt_obj.get(), GetImageOffset(interned));
+      SetImageOffset(obj, GetImageOffset(interned));
       return;
     }
     // else (obj == interned), nothing to do but fall through to the normal case
@@ -404,20 +402,22 @@
   Runtime* runtime = Runtime::Current();
   ClassLinker* class_linker = runtime->GetClassLinker();
   Thread* self = Thread::Current();
-  SirtRef<Class> object_array_class(self, class_linker->FindSystemClass(self,
-                                                                        "[Ljava/lang/Object;"));
+  StackHandleScope<3> hs(self);
+  Handle<Class> object_array_class(hs.NewHandle(
+      class_linker->FindSystemClass(self, "[Ljava/lang/Object;")));
 
   // build an Object[] of all the DexCaches used in the source_space_
-  ObjectArray<Object>* dex_caches = ObjectArray<Object>::Alloc(self, object_array_class.get(),
-                                                               class_linker->GetDexCaches().size());
+  Handle<ObjectArray<Object>> dex_caches(
+      hs.NewHandle(ObjectArray<Object>::Alloc(self, object_array_class.Get(),
+                                              class_linker->GetDexCaches().size())));
   int i = 0;
   for (DexCache* dex_cache : class_linker->GetDexCaches()) {
     dex_caches->Set<false>(i++, dex_cache);
   }
 
   // build an Object[] of the roots needed to restore the runtime
-  SirtRef<ObjectArray<Object> > image_roots(
-      self, ObjectArray<Object>::Alloc(self, object_array_class.get(), ImageHeader::kImageRootsMax));
+  Handle<ObjectArray<Object> > image_roots(hs.NewHandle(
+      ObjectArray<Object>::Alloc(self, object_array_class.Get(), ImageHeader::kImageRootsMax)));
   image_roots->Set<false>(ImageHeader::kResolutionMethod, runtime->GetResolutionMethod());
   image_roots->Set<false>(ImageHeader::kImtConflictMethod, runtime->GetImtConflictMethod());
   image_roots->Set<false>(ImageHeader::kDefaultImt, runtime->GetDefaultImt());
@@ -427,27 +427,28 @@
                           runtime->GetCalleeSaveMethod(Runtime::kRefsOnly));
   image_roots->Set<false>(ImageHeader::kRefsAndArgsSaveMethod,
                           runtime->GetCalleeSaveMethod(Runtime::kRefsAndArgs));
-  image_roots->Set<false>(ImageHeader::kDexCaches, dex_caches);
+  image_roots->Set<false>(ImageHeader::kDexCaches, dex_caches.Get());
   image_roots->Set<false>(ImageHeader::kClassRoots, class_linker->GetClassRoots());
   for (int i = 0; i < ImageHeader::kImageRootsMax; i++) {
     CHECK(image_roots->Get(i) != NULL);
   }
-  return image_roots.get();
+  return image_roots.Get();
 }
 
 // Walk instance fields of the given Class. Separate function to allow recursion on the super
 // class.
 void ImageWriter::WalkInstanceFields(mirror::Object* obj, mirror::Class* klass) {
   // Visit fields of parent classes first.
-  SirtRef<mirror::Class> sirt_class(Thread::Current(), klass);
-  mirror::Class* super = sirt_class->GetSuperClass();
+  StackHandleScope<1> hs(Thread::Current());
+  Handle<mirror::Class> h_class(hs.NewHandle(klass));
+  mirror::Class* super = h_class->GetSuperClass();
   if (super != nullptr) {
     WalkInstanceFields(obj, super);
   }
   //
-  size_t num_reference_fields = sirt_class->NumReferenceInstanceFields();
+  size_t num_reference_fields = h_class->NumReferenceInstanceFields();
   for (size_t i = 0; i < num_reference_fields; ++i) {
-    mirror::ArtField* field = sirt_class->GetInstanceField(i);
+    mirror::ArtField* field = h_class->GetInstanceField(i);
     MemberOffset field_offset = field->GetOffset();
     mirror::Object* value = obj->GetFieldObject<mirror::Object>(field_offset);
     if (value != nullptr) {
@@ -460,28 +461,28 @@
 void ImageWriter::WalkFieldsInOrder(mirror::Object* obj) {
   if (!IsImageOffsetAssigned(obj)) {
     // Walk instance fields of all objects
-    Thread* self = Thread::Current();
-    SirtRef<mirror::Object> sirt_obj(self, obj);
-    SirtRef<mirror::Class> klass(self, obj->GetClass());
+    StackHandleScope<2> hs(Thread::Current());
+    Handle<mirror::Object> h_obj(hs.NewHandle(obj));
+    Handle<mirror::Class> klass(hs.NewHandle(obj->GetClass()));
     // visit the object itself.
-    CalculateObjectOffsets(sirt_obj.get());
-    WalkInstanceFields(sirt_obj.get(), klass.get());
+    CalculateObjectOffsets(h_obj.Get());
+    WalkInstanceFields(h_obj.Get(), klass.Get());
     // Walk static fields of a Class.
-    if (sirt_obj->IsClass()) {
+    if (h_obj->IsClass()) {
       size_t num_static_fields = klass->NumReferenceStaticFields();
       for (size_t i = 0; i < num_static_fields; ++i) {
         mirror::ArtField* field = klass->GetStaticField(i);
         MemberOffset field_offset = field->GetOffset();
-        mirror::Object* value = sirt_obj->GetFieldObject<mirror::Object>(field_offset);
+        mirror::Object* value = h_obj->GetFieldObject<mirror::Object>(field_offset);
         if (value != nullptr) {
           WalkFieldsInOrder(value);
         }
       }
-    } else if (sirt_obj->IsObjectArray()) {
+    } else if (h_obj->IsObjectArray()) {
       // Walk elements of an object array.
-      int32_t length = sirt_obj->AsObjectArray<mirror::Object>()->GetLength();
+      int32_t length = h_obj->AsObjectArray<mirror::Object>()->GetLength();
       for (int32_t i = 0; i < length; i++) {
-        mirror::ObjectArray<mirror::Object>* obj_array = sirt_obj->AsObjectArray<mirror::Object>();
+        mirror::ObjectArray<mirror::Object>* obj_array = h_obj->AsObjectArray<mirror::Object>();
         mirror::Object* value = obj_array->Get(i);
         if (value != nullptr) {
           WalkFieldsInOrder(value);
@@ -500,7 +501,8 @@
 void ImageWriter::CalculateNewObjectOffsets(size_t oat_loaded_size, size_t oat_data_offset) {
   CHECK_NE(0U, oat_loaded_size);
   Thread* self = Thread::Current();
-  SirtRef<ObjectArray<Object> > image_roots(self, CreateImageRoots());
+  StackHandleScope<1> hs(self);
+  Handle<ObjectArray<Object>> image_roots(hs.NewHandle(CreateImageRoots()));
 
   gc::Heap* heap = Runtime::Current()->GetHeap();
   DCHECK_EQ(0U, image_end_);
@@ -533,7 +535,7 @@
                            static_cast<uint32_t>(image_end_),
                            RoundUp(image_end_, kPageSize),
                            RoundUp(bitmap_bytes, kPageSize),
-                           PointerToLowMemUInt32(GetImageAddress(image_roots.get())),
+                           PointerToLowMemUInt32(GetImageAddress(image_roots.Get())),
                            oat_file_->GetOatHeader().GetChecksum(),
                            PointerToLowMemUInt32(oat_file_begin),
                            PointerToLowMemUInt32(oat_data_begin_),
@@ -691,9 +693,10 @@
 static ArtMethod* GetTargetMethod(const CompilerDriver::CallPatchInformation* patch)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
   ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
-  Thread* self = Thread::Current();
-  SirtRef<mirror::DexCache> dex_cache(self, class_linker->FindDexCache(*patch->GetTargetDexFile()));
-  SirtRef<mirror::ClassLoader> class_loader(self, nullptr);
+  StackHandleScope<2> hs(Thread::Current());
+  Handle<mirror::DexCache> dex_cache(
+      hs.NewHandle(class_linker->FindDexCache(*patch->GetTargetDexFile())));
+  auto class_loader(hs.NewHandle<mirror::ClassLoader>(nullptr));
   ArtMethod* method = class_linker->ResolveMethod(*patch->GetTargetDexFile(),
                                                   patch->GetTargetMethodIdx(),
                                                   dex_cache,
@@ -714,9 +717,9 @@
 static Class* GetTargetType(const CompilerDriver::TypePatchInformation* patch)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
   ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
-  Thread* self = Thread::Current();
-  SirtRef<mirror::DexCache> dex_cache(self, class_linker->FindDexCache(patch->GetDexFile()));
-  SirtRef<mirror::ClassLoader> class_loader(self, nullptr);
+  StackHandleScope<2> hs(Thread::Current());
+  Handle<mirror::DexCache> dex_cache(hs.NewHandle(class_linker->FindDexCache(patch->GetDexFile())));
+  auto class_loader(hs.NewHandle<mirror::ClassLoader>(nullptr));
   Class* klass = class_linker->ResolveType(patch->GetDexFile(),
                                            patch->GetTargetTypeIdx(),
                                            dex_cache,
diff --git a/compiler/jni/jni_compiler_test.cc b/compiler/jni/jni_compiler_test.cc
index 6b5e55e..6035689 100644
--- a/compiler/jni/jni_compiler_test.cc
+++ b/compiler/jni/jni_compiler_test.cc
@@ -48,7 +48,9 @@
   void CompileForTest(jobject class_loader, bool direct,
                       const char* method_name, const char* method_sig) {
     ScopedObjectAccess soa(Thread::Current());
-    SirtRef<mirror::ClassLoader> loader(soa.Self(), soa.Decode<mirror::ClassLoader*>(class_loader));
+    StackHandleScope<1> hs(soa.Self());
+    Handle<mirror::ClassLoader> loader(
+        hs.NewHandle(soa.Decode<mirror::ClassLoader*>(class_loader)));
     // Compile the native method before starting the runtime
     mirror::Class* c = class_linker_->FindClass(soa.Self(), "LMyClassNatives;", loader);
     mirror::ArtMethod* method;
@@ -153,8 +155,9 @@
 
   ScopedObjectAccess soa(Thread::Current());
   std::string reason;
-  SirtRef<mirror::ClassLoader> class_loader(soa.Self(),
-                                            soa.Decode<mirror::ClassLoader*>(class_loader_));
+  StackHandleScope<1> hs(soa.Self());
+  Handle<mirror::ClassLoader> class_loader(
+      hs.NewHandle(soa.Decode<mirror::ClassLoader*>(class_loader_)));
   ASSERT_TRUE(
       Runtime::Current()->GetJavaVM()->LoadNativeLibrary("", class_loader, &reason)) << reason;
 
@@ -169,8 +172,9 @@
 
   ScopedObjectAccess soa(Thread::Current());
   std::string reason;
-  SirtRef<mirror::ClassLoader> class_loader(soa.Self(),
-                                            soa.Decode<mirror::ClassLoader*>(class_loader_));
+  StackHandleScope<1> hs(soa.Self());
+  Handle<mirror::ClassLoader> class_loader(
+      hs.NewHandle(soa.Decode<mirror::ClassLoader*>(class_loader_)));
   ASSERT_TRUE(
       Runtime::Current()->GetJavaVM()->LoadNativeLibrary("", class_loader, &reason)) << reason;
 
diff --git a/compiler/jni/portable/jni_compiler.cc b/compiler/jni/portable/jni_compiler.cc
index 0c14346..d2f54f8 100644
--- a/compiler/jni/portable/jni_compiler.cc
+++ b/compiler/jni/portable/jni_compiler.cc
@@ -98,7 +98,7 @@
   arg_begin = arg_iter;
 
   // Count the number of Object* arguments
-  uint32_t sirt_size = 1;
+  uint32_t handle_scope_size = 1;
   // "this" object pointer for non-static
   // "class" object pointer for static
   for (unsigned i = 0; arg_iter != arg_end; ++i, ++arg_iter) {
@@ -106,12 +106,12 @@
     arg_iter->setName(StringPrintf("a%u", i));
 #endif
     if (arg_iter->getType() == irb_.getJObjectTy()) {
-      ++sirt_size;
+      ++handle_scope_size;
     }
   }
 
   // Shadow stack
-  ::llvm::StructType* shadow_frame_type = irb_.getShadowFrameTy(sirt_size);
+  ::llvm::StructType* shadow_frame_type = irb_.getShadowFrameTy(handle_scope_size);
   ::llvm::AllocaInst* shadow_frame_ = irb_.CreateAlloca(shadow_frame_type);
 
   // Store the dex pc
@@ -123,7 +123,7 @@
   // Push the shadow frame
   ::llvm::Value* shadow_frame_upcast = irb_.CreateConstGEP2_32(shadow_frame_, 0, 0);
   ::llvm::Value* old_shadow_frame =
-      irb_.Runtime().EmitPushShadowFrame(shadow_frame_upcast, method_object_addr, sirt_size);
+      irb_.Runtime().EmitPushShadowFrame(shadow_frame_upcast, method_object_addr, handle_scope_size);
 
   // Get JNIEnv
   ::llvm::Value* jni_env_object_addr =
@@ -148,35 +148,35 @@
   // Variables for GetElementPtr
   ::llvm::Value* gep_index[] = {
     irb_.getInt32(0),  // No displacement for shadow frame pointer
-    irb_.getInt32(1),  // SIRT
+    irb_.getInt32(1),  // handle scope
     NULL,
   };
 
-  size_t sirt_member_index = 0;
+  size_t handle_scope_member_index = 0;
 
-  // Store the "this object or class object" to SIRT
-  gep_index[2] = irb_.getInt32(sirt_member_index++);
-  ::llvm::Value* sirt_field_addr = irb_.CreateBitCast(irb_.CreateGEP(shadow_frame_, gep_index),
+  // Store the "this object or class object" to handle scope
+  gep_index[2] = irb_.getInt32(handle_scope_member_index++);
+  ::llvm::Value* handle_scope_field_addr = irb_.CreateBitCast(irb_.CreateGEP(shadow_frame_, gep_index),
                                                     irb_.getJObjectTy()->getPointerTo());
-  irb_.CreateStore(this_object_or_class_object, sirt_field_addr, kTBAAShadowFrame);
+  irb_.CreateStore(this_object_or_class_object, handle_scope_field_addr, kTBAAShadowFrame);
   // Push the "this object or class object" to out args
-  this_object_or_class_object = irb_.CreateBitCast(sirt_field_addr, irb_.getJObjectTy());
+  this_object_or_class_object = irb_.CreateBitCast(handle_scope_field_addr, irb_.getJObjectTy());
   args.push_back(this_object_or_class_object);
-  // Store arguments to SIRT, and push back to args
+  // Store arguments to handle scope, and push back to args
   for (arg_iter = arg_begin; arg_iter != arg_end; ++arg_iter) {
     if (arg_iter->getType() == irb_.getJObjectTy()) {
-      // Store the reference type arguments to SIRT
-      gep_index[2] = irb_.getInt32(sirt_member_index++);
-      ::llvm::Value* sirt_field_addr = irb_.CreateBitCast(irb_.CreateGEP(shadow_frame_, gep_index),
+      // Store the reference type arguments to handle scope
+      gep_index[2] = irb_.getInt32(handle_scope_member_index++);
+      ::llvm::Value* handle_scope_field_addr = irb_.CreateBitCast(irb_.CreateGEP(shadow_frame_, gep_index),
                                                         irb_.getJObjectTy()->getPointerTo());
-      irb_.CreateStore(arg_iter, sirt_field_addr, kTBAAShadowFrame);
-      // Note null is placed in the SIRT but the jobject passed to the native code must be null
-      // (not a pointer into the SIRT as with regular references).
+      irb_.CreateStore(arg_iter, handle_scope_field_addr, kTBAAShadowFrame);
+      // Note null is placed in the handle scope but the jobject passed to the native code must be null
+      // (not a pointer into the handle scope as with regular references).
       ::llvm::Value* equal_null = irb_.CreateICmpEQ(arg_iter, irb_.getJNull());
       ::llvm::Value* arg =
           irb_.CreateSelect(equal_null,
                             irb_.getJNull(),
-                            irb_.CreateBitCast(sirt_field_addr, irb_.getJObjectTy()));
+                            irb_.CreateBitCast(handle_scope_field_addr, irb_.getJObjectTy()));
       args.push_back(arg);
     } else {
       args.push_back(arg_iter);
diff --git a/compiler/jni/quick/arm/calling_convention_arm.cc b/compiler/jni/quick/arm/calling_convention_arm.cc
index ae18d2e..649a80f 100644
--- a/compiler/jni/quick/arm/calling_convention_arm.cc
+++ b/compiler/jni/quick/arm/calling_convention_arm.cc
@@ -144,10 +144,10 @@
 size_t ArmJniCallingConvention::FrameSize() {
   // Method*, LR and callee save area size, local reference segment state
   size_t frame_data_size = (3 + CalleeSaveRegisters().size()) * kFramePointerSize;
-  // References plus 2 words for SIRT header
-  size_t sirt_size = StackIndirectReferenceTable::GetAlignedSirtSizeTarget(kFramePointerSize, ReferenceCount());
+  // References plus 2 words for HandleScope header
+  size_t handle_scope_size = HandleScope::GetAlignedHandleScopeSizeTarget(kFramePointerSize, ReferenceCount());
   // Plus return value spill area size
-  return RoundUp(frame_data_size + sirt_size + SizeOfReturnValue(), kStackAlignment);
+  return RoundUp(frame_data_size + handle_scope_size + SizeOfReturnValue(), kStackAlignment);
 }
 
 size_t ArmJniCallingConvention::OutArgSize() {
diff --git a/compiler/jni/quick/arm64/calling_convention_arm64.cc b/compiler/jni/quick/arm64/calling_convention_arm64.cc
index 6212a23..ffd27ee 100644
--- a/compiler/jni/quick/arm64/calling_convention_arm64.cc
+++ b/compiler/jni/quick/arm64/calling_convention_arm64.cc
@@ -197,10 +197,10 @@
 size_t Arm64JniCallingConvention::FrameSize() {
   // Method*, callee save area size, local reference segment state
   size_t frame_data_size = ((1 + CalleeSaveRegisters().size()) * kFramePointerSize) + sizeof(uint32_t);
-  // References plus 2 words for SIRT header
-  size_t sirt_size = StackIndirectReferenceTable::GetAlignedSirtSizeTarget(kFramePointerSize, ReferenceCount());
+  // References plus 2 words for HandleScope header
+  size_t handle_scope_size = HandleScope::GetAlignedHandleScopeSizeTarget(kFramePointerSize, ReferenceCount());
   // Plus return value spill area size
-  return RoundUp(frame_data_size + sirt_size + SizeOfReturnValue(), kStackAlignment);
+  return RoundUp(frame_data_size + handle_scope_size + SizeOfReturnValue(), kStackAlignment);
 }
 
 size_t Arm64JniCallingConvention::OutArgSize() {
diff --git a/compiler/jni/quick/calling_convention.cc b/compiler/jni/quick/calling_convention.cc
index a99a4c2..95c2d40 100644
--- a/compiler/jni/quick/calling_convention.cc
+++ b/compiler/jni/quick/calling_convention.cc
@@ -126,8 +126,8 @@
 }
 
 FrameOffset JniCallingConvention::SavedLocalReferenceCookieOffset() const {
-  size_t references_size = sirt_pointer_size_ * ReferenceCount();  // size excluding header
-  return FrameOffset(SirtReferencesOffset().Int32Value() + references_size);
+  size_t references_size = handle_scope_pointer_size_ * ReferenceCount();  // size excluding header
+  return FrameOffset(HandleerencesOffset().Int32Value() + references_size);
 }
 
 FrameOffset JniCallingConvention::ReturnValueSaveLocation() const {
@@ -219,13 +219,13 @@
   }
 }
 
-// Return position of SIRT entry holding reference at the current iterator
+// Return position of handle scope entry holding reference at the current iterator
 // position
-FrameOffset JniCallingConvention::CurrentParamSirtEntryOffset() {
+FrameOffset JniCallingConvention::CurrentParamHandleScopeEntryOffset() {
   CHECK(IsCurrentParamAReference());
-  CHECK_LT(SirtLinkOffset(), SirtNumRefsOffset());
-  int result = SirtReferencesOffset().Int32Value() + itr_refs_ * sirt_pointer_size_;
-  CHECK_GT(result, SirtNumRefsOffset().Int32Value());
+  CHECK_LT(HandleScopeLinkOffset(), HandleScopeNumRefsOffset());
+  int result = HandleerencesOffset().Int32Value() + itr_refs_ * handle_scope_pointer_size_;
+  CHECK_GT(result, HandleScopeNumRefsOffset().Int32Value());
   return FrameOffset(result);
 }
 
diff --git a/compiler/jni/quick/calling_convention.h b/compiler/jni/quick/calling_convention.h
index 18afd58..2a6e7d9 100644
--- a/compiler/jni/quick/calling_convention.h
+++ b/compiler/jni/quick/calling_convention.h
@@ -18,7 +18,7 @@
 #define ART_COMPILER_JNI_QUICK_CALLING_CONVENTION_H_
 
 #include <vector>
-#include "stack_indirect_reference_table.h"
+#include "handle_scope.h"
 #include "thread.h"
 #include "utils/managed_register.h"
 
@@ -73,7 +73,7 @@
       : itr_slots_(0), itr_refs_(0), itr_args_(0), itr_longs_and_doubles_(0),
         itr_float_and_doubles_(0), displacement_(0),
         frame_pointer_size_(frame_pointer_size),
-        sirt_pointer_size_(sizeof(StackReference<mirror::Object>)),
+        handle_scope_pointer_size_(sizeof(StackReference<mirror::Object>)),
         is_static_(is_static), is_synchronized_(is_synchronized),
         shorty_(shorty) {
     num_args_ = (is_static ? 0 : 1) + strlen(shorty) - 1;
@@ -197,8 +197,8 @@
   FrameOffset displacement_;
   // The size of a reference.
   const size_t frame_pointer_size_;
-  // The size of a reference entry within the SIRT.
-  const size_t sirt_pointer_size_;
+  // The size of a reference entry within the handle scope.
+  const size_t handle_scope_pointer_size_;
 
  private:
   const bool is_static_;
@@ -315,26 +315,25 @@
   virtual FrameOffset CurrentParamStackOffset() = 0;
 
   // Iterator interface extension for JNI
-  FrameOffset CurrentParamSirtEntryOffset();
+  FrameOffset CurrentParamHandleScopeEntryOffset();
 
-  // Position of SIRT and interior fields
-  FrameOffset SirtOffset() const {
+  // Position of handle scope and interior fields
+  FrameOffset HandleScopeOffset() const {
     return FrameOffset(this->displacement_.Int32Value() + frame_pointer_size_);  // above Method*
   }
 
-  FrameOffset SirtLinkOffset() const {
-    return FrameOffset(SirtOffset().Int32Value() +
-                       StackIndirectReferenceTable::LinkOffset(frame_pointer_size_));
+  FrameOffset HandleScopeLinkOffset() const {
+    return FrameOffset(HandleScopeOffset().Int32Value() + HandleScope::LinkOffset(frame_pointer_size_));
   }
 
-  FrameOffset SirtNumRefsOffset() const {
-    return FrameOffset(SirtOffset().Int32Value() +
-                       StackIndirectReferenceTable::NumberOfReferencesOffset(frame_pointer_size_));
+  FrameOffset HandleScopeNumRefsOffset() const {
+    return FrameOffset(HandleScopeOffset().Int32Value() +
+                       HandleScope::NumberOfReferencesOffset(frame_pointer_size_));
   }
 
-  FrameOffset SirtReferencesOffset() const {
-    return FrameOffset(SirtOffset().Int32Value() +
-                       StackIndirectReferenceTable::ReferencesOffset(frame_pointer_size_));
+  FrameOffset HandleerencesOffset() const {
+    return FrameOffset(HandleScopeOffset().Int32Value() +
+                       HandleScope::ReferencesOffset(frame_pointer_size_));
   }
 
   virtual ~JniCallingConvention() {}
@@ -350,7 +349,7 @@
                                 size_t frame_pointer_size)
       : CallingConvention(is_static, is_synchronized, shorty, frame_pointer_size) {}
 
-  // Number of stack slots for outgoing arguments, above which the SIRT is
+  // Number of stack slots for outgoing arguments, above which the handle scope is
   // located
   virtual size_t NumberOfOutgoingStackArgs() = 0;
 
diff --git a/compiler/jni/quick/jni_compiler.cc b/compiler/jni/quick/jni_compiler.cc
index 5a22170..20f9f4b 100644
--- a/compiler/jni/quick/jni_compiler.cc
+++ b/compiler/jni/quick/jni_compiler.cc
@@ -103,54 +103,54 @@
   const std::vector<ManagedRegister>& callee_save_regs = main_jni_conv->CalleeSaveRegisters();
   __ BuildFrame(frame_size, mr_conv->MethodRegister(), callee_save_regs, mr_conv->EntrySpills());
 
-  // 2. Set up the StackIndirectReferenceTable
+  // 2. Set up the HandleScope
   mr_conv->ResetIterator(FrameOffset(frame_size));
   main_jni_conv->ResetIterator(FrameOffset(0));
-  __ StoreImmediateToFrame(main_jni_conv->SirtNumRefsOffset(),
+  __ StoreImmediateToFrame(main_jni_conv->HandleScopeNumRefsOffset(),
                            main_jni_conv->ReferenceCount(),
                            mr_conv->InterproceduralScratchRegister());
 
   if (is_64_bit_target) {
-    __ CopyRawPtrFromThread64(main_jni_conv->SirtLinkOffset(),
-                            Thread::TopSirtOffset<8>(),
+    __ CopyRawPtrFromThread64(main_jni_conv->HandleScopeLinkOffset(),
+                            Thread::TopHandleScopeOffset<8>(),
                             mr_conv->InterproceduralScratchRegister());
-    __ StoreStackOffsetToThread64(Thread::TopSirtOffset<8>(),
-                                main_jni_conv->SirtOffset(),
+    __ StoreStackOffsetToThread64(Thread::TopHandleScopeOffset<8>(),
+                                main_jni_conv->HandleScopeOffset(),
                                 mr_conv->InterproceduralScratchRegister());
   } else {
-    __ CopyRawPtrFromThread32(main_jni_conv->SirtLinkOffset(),
-                            Thread::TopSirtOffset<4>(),
+    __ CopyRawPtrFromThread32(main_jni_conv->HandleScopeLinkOffset(),
+                            Thread::TopHandleScopeOffset<4>(),
                             mr_conv->InterproceduralScratchRegister());
-    __ StoreStackOffsetToThread32(Thread::TopSirtOffset<4>(),
-                                main_jni_conv->SirtOffset(),
+    __ StoreStackOffsetToThread32(Thread::TopHandleScopeOffset<4>(),
+                                main_jni_conv->HandleScopeOffset(),
                                 mr_conv->InterproceduralScratchRegister());
   }
 
-  // 3. Place incoming reference arguments into SIRT
+  // 3. Place incoming reference arguments into handle scope
   main_jni_conv->Next();  // Skip JNIEnv*
   // 3.5. Create Class argument for static methods out of passed method
   if (is_static) {
-    FrameOffset sirt_offset = main_jni_conv->CurrentParamSirtEntryOffset();
-    // Check sirt offset is within frame
-    CHECK_LT(sirt_offset.Uint32Value(), frame_size);
+    FrameOffset handle_scope_offset = main_jni_conv->CurrentParamHandleScopeEntryOffset();
+    // Check handle scope offset is within frame
+    CHECK_LT(handle_scope_offset.Uint32Value(), frame_size);
     __ LoadRef(main_jni_conv->InterproceduralScratchRegister(),
                mr_conv->MethodRegister(), mirror::ArtMethod::DeclaringClassOffset());
     __ VerifyObject(main_jni_conv->InterproceduralScratchRegister(), false);
-    __ StoreRef(sirt_offset, main_jni_conv->InterproceduralScratchRegister());
-    main_jni_conv->Next();  // in SIRT so move to next argument
+    __ StoreRef(handle_scope_offset, main_jni_conv->InterproceduralScratchRegister());
+    main_jni_conv->Next();  // in handle scope so move to next argument
   }
   while (mr_conv->HasNext()) {
     CHECK(main_jni_conv->HasNext());
     bool ref_param = main_jni_conv->IsCurrentParamAReference();
     CHECK(!ref_param || mr_conv->IsCurrentParamAReference());
-    // References need placing in SIRT and the entry value passing
+    // References need placing in handle scope and the entry value passing
     if (ref_param) {
-      // Compute SIRT entry, note null is placed in the SIRT but its boxed value
+      // Compute handle scope entry, note null is placed in the handle scope but its boxed value
       // must be NULL
-      FrameOffset sirt_offset = main_jni_conv->CurrentParamSirtEntryOffset();
-      // Check SIRT offset is within frame and doesn't run into the saved segment state
-      CHECK_LT(sirt_offset.Uint32Value(), frame_size);
-      CHECK_NE(sirt_offset.Uint32Value(),
+      FrameOffset handle_scope_offset = main_jni_conv->CurrentParamHandleScopeEntryOffset();
+      // Check handle scope offset is within frame and doesn't run into the saved segment state
+      CHECK_LT(handle_scope_offset.Uint32Value(), frame_size);
+      CHECK_NE(handle_scope_offset.Uint32Value(),
                main_jni_conv->SavedLocalReferenceCookieOffset().Uint32Value());
       bool input_in_reg = mr_conv->IsCurrentParamInRegister();
       bool input_on_stack = mr_conv->IsCurrentParamOnStack();
@@ -159,11 +159,11 @@
       if (input_in_reg) {
         ManagedRegister in_reg  =  mr_conv->CurrentParamRegister();
         __ VerifyObject(in_reg, mr_conv->IsCurrentArgPossiblyNull());
-        __ StoreRef(sirt_offset, in_reg);
+        __ StoreRef(handle_scope_offset, in_reg);
       } else if (input_on_stack) {
         FrameOffset in_off  = mr_conv->CurrentParamStackOffset();
         __ VerifyObject(in_off, mr_conv->IsCurrentArgPossiblyNull());
-        __ CopyRef(sirt_offset, in_off,
+        __ CopyRef(handle_scope_offset, in_off,
                    mr_conv->InterproceduralScratchRegister());
       }
     }
@@ -197,20 +197,20 @@
   ThreadOffset<8> jni_start64 = is_synchronized ? QUICK_ENTRYPOINT_OFFSET(8, pJniMethodStartSynchronized)
                                                 : QUICK_ENTRYPOINT_OFFSET(8, pJniMethodStart);
   main_jni_conv->ResetIterator(FrameOffset(main_out_arg_size));
-  FrameOffset locked_object_sirt_offset(0);
+  FrameOffset locked_object_handle_scope_offset(0);
   if (is_synchronized) {
     // Pass object for locking.
     main_jni_conv->Next();  // Skip JNIEnv.
-    locked_object_sirt_offset = main_jni_conv->CurrentParamSirtEntryOffset();
+    locked_object_handle_scope_offset = main_jni_conv->CurrentParamHandleScopeEntryOffset();
     main_jni_conv->ResetIterator(FrameOffset(main_out_arg_size));
     if (main_jni_conv->IsCurrentParamOnStack()) {
       FrameOffset out_off = main_jni_conv->CurrentParamStackOffset();
-      __ CreateSirtEntry(out_off, locked_object_sirt_offset,
+      __ CreateHandleScopeEntry(out_off, locked_object_handle_scope_offset,
                          mr_conv->InterproceduralScratchRegister(),
                          false);
     } else {
       ManagedRegister out_reg = main_jni_conv->CurrentParamRegister();
-      __ CreateSirtEntry(out_reg, locked_object_sirt_offset,
+      __ CreateHandleScopeEntry(out_reg, locked_object_handle_scope_offset,
                          ManagedRegister::NoRegister(), false);
     }
     main_jni_conv->Next();
@@ -274,15 +274,15 @@
     mr_conv->ResetIterator(FrameOffset(frame_size+main_out_arg_size));
     main_jni_conv->ResetIterator(FrameOffset(main_out_arg_size));
     main_jni_conv->Next();  // Skip JNIEnv*
-    FrameOffset sirt_offset = main_jni_conv->CurrentParamSirtEntryOffset();
+    FrameOffset handle_scope_offset = main_jni_conv->CurrentParamHandleScopeEntryOffset();
     if (main_jni_conv->IsCurrentParamOnStack()) {
       FrameOffset out_off = main_jni_conv->CurrentParamStackOffset();
-      __ CreateSirtEntry(out_off, sirt_offset,
+      __ CreateHandleScopeEntry(out_off, handle_scope_offset,
                          mr_conv->InterproceduralScratchRegister(),
                          false);
     } else {
       ManagedRegister out_reg = main_jni_conv->CurrentParamRegister();
-      __ CreateSirtEntry(out_reg, sirt_offset,
+      __ CreateHandleScopeEntry(out_reg, handle_scope_offset,
                          ManagedRegister::NoRegister(), false);
     }
   }
@@ -369,12 +369,12 @@
     // Pass object for unlocking.
     if (end_jni_conv->IsCurrentParamOnStack()) {
       FrameOffset out_off = end_jni_conv->CurrentParamStackOffset();
-      __ CreateSirtEntry(out_off, locked_object_sirt_offset,
+      __ CreateHandleScopeEntry(out_off, locked_object_handle_scope_offset,
                          end_jni_conv->InterproceduralScratchRegister(),
                          false);
     } else {
       ManagedRegister out_reg = end_jni_conv->CurrentParamRegister();
-      __ CreateSirtEntry(out_reg, locked_object_sirt_offset,
+      __ CreateHandleScopeEntry(out_reg, locked_object_handle_scope_offset,
                          ManagedRegister::NoRegister(), false);
     }
     end_jni_conv->Next();
@@ -438,7 +438,7 @@
                           size_t frame_size, size_t out_arg_size) {
   bool input_in_reg = mr_conv->IsCurrentParamInRegister();
   bool output_in_reg = jni_conv->IsCurrentParamInRegister();
-  FrameOffset sirt_offset(0);
+  FrameOffset handle_scope_offset(0);
   bool null_allowed = false;
   bool ref_param = jni_conv->IsCurrentParamAReference();
   CHECK(!ref_param || mr_conv->IsCurrentParamAReference());
@@ -449,21 +449,21 @@
   } else {
     CHECK(jni_conv->IsCurrentParamOnStack());
   }
-  // References need placing in SIRT and the entry address passing
+  // References need placing in handle scope and the entry address passing
   if (ref_param) {
     null_allowed = mr_conv->IsCurrentArgPossiblyNull();
-    // Compute SIRT offset. Note null is placed in the SIRT but the jobject
-    // passed to the native code must be null (not a pointer into the SIRT
+    // Compute handle scope offset. Note null is placed in the handle scope but the jobject
+    // passed to the native code must be null (not a pointer into the handle scope
     // as with regular references).
-    sirt_offset = jni_conv->CurrentParamSirtEntryOffset();
-    // Check SIRT offset is within frame.
-    CHECK_LT(sirt_offset.Uint32Value(), (frame_size + out_arg_size));
+    handle_scope_offset = jni_conv->CurrentParamHandleScopeEntryOffset();
+    // Check handle scope offset is within frame.
+    CHECK_LT(handle_scope_offset.Uint32Value(), (frame_size + out_arg_size));
   }
   if (input_in_reg && output_in_reg) {
     ManagedRegister in_reg = mr_conv->CurrentParamRegister();
     ManagedRegister out_reg = jni_conv->CurrentParamRegister();
     if (ref_param) {
-      __ CreateSirtEntry(out_reg, sirt_offset, in_reg, null_allowed);
+      __ CreateHandleScopeEntry(out_reg, handle_scope_offset, in_reg, null_allowed);
     } else {
       if (!mr_conv->IsCurrentParamOnStack()) {
         // regular non-straddling move
@@ -475,7 +475,7 @@
   } else if (!input_in_reg && !output_in_reg) {
     FrameOffset out_off = jni_conv->CurrentParamStackOffset();
     if (ref_param) {
-      __ CreateSirtEntry(out_off, sirt_offset, mr_conv->InterproceduralScratchRegister(),
+      __ CreateHandleScopeEntry(out_off, handle_scope_offset, mr_conv->InterproceduralScratchRegister(),
                          null_allowed);
     } else {
       FrameOffset in_off = mr_conv->CurrentParamStackOffset();
@@ -489,7 +489,7 @@
     // Check that incoming stack arguments are above the current stack frame.
     CHECK_GT(in_off.Uint32Value(), frame_size);
     if (ref_param) {
-      __ CreateSirtEntry(out_reg, sirt_offset, ManagedRegister::NoRegister(), null_allowed);
+      __ CreateHandleScopeEntry(out_reg, handle_scope_offset, ManagedRegister::NoRegister(), null_allowed);
     } else {
       size_t param_size = mr_conv->CurrentParamSize();
       CHECK_EQ(param_size, jni_conv->CurrentParamSize());
@@ -502,8 +502,8 @@
     // Check outgoing argument is within frame
     CHECK_LT(out_off.Uint32Value(), frame_size);
     if (ref_param) {
-      // TODO: recycle value in in_reg rather than reload from SIRT
-      __ CreateSirtEntry(out_off, sirt_offset, mr_conv->InterproceduralScratchRegister(),
+      // TODO: recycle value in in_reg rather than reload from handle scope
+      __ CreateHandleScopeEntry(out_off, handle_scope_offset, mr_conv->InterproceduralScratchRegister(),
                          null_allowed);
     } else {
       size_t param_size = mr_conv->CurrentParamSize();
diff --git a/compiler/jni/quick/mips/calling_convention_mips.cc b/compiler/jni/quick/mips/calling_convention_mips.cc
index 8e1c0c7..0402fe6 100644
--- a/compiler/jni/quick/mips/calling_convention_mips.cc
+++ b/compiler/jni/quick/mips/calling_convention_mips.cc
@@ -148,10 +148,10 @@
 size_t MipsJniCallingConvention::FrameSize() {
   // Method*, LR and callee save area size, local reference segment state
   size_t frame_data_size = (3 + CalleeSaveRegisters().size()) * kFramePointerSize;
-  // References plus 2 words for SIRT header
-  size_t sirt_size = StackIndirectReferenceTable::GetAlignedSirtSizeTarget(kFramePointerSize, ReferenceCount());
+  // References plus 2 words for HandleScope header
+  size_t handle_scope_size = HandleScope::GetAlignedHandleScopeSizeTarget(kFramePointerSize, ReferenceCount());
   // Plus return value spill area size
-  return RoundUp(frame_data_size + sirt_size + SizeOfReturnValue(), kStackAlignment);
+  return RoundUp(frame_data_size + handle_scope_size + SizeOfReturnValue(), kStackAlignment);
 }
 
 size_t MipsJniCallingConvention::OutArgSize() {
diff --git a/compiler/jni/quick/x86/calling_convention_x86.cc b/compiler/jni/quick/x86/calling_convention_x86.cc
index 153f953..97b4cdf 100644
--- a/compiler/jni/quick/x86/calling_convention_x86.cc
+++ b/compiler/jni/quick/x86/calling_convention_x86.cc
@@ -125,10 +125,10 @@
 size_t X86JniCallingConvention::FrameSize() {
   // Method*, return address and callee save area size, local reference segment state
   size_t frame_data_size = (3 + CalleeSaveRegisters().size()) * kFramePointerSize;
-  // References plus 2 words for SIRT header
-  size_t sirt_size = StackIndirectReferenceTable::GetAlignedSirtSizeTarget(kFramePointerSize, ReferenceCount());
+  // References plus 2 words for HandleScope header
+  size_t handle_scope_size = HandleScope::GetAlignedHandleScopeSizeTarget(kFramePointerSize, ReferenceCount());
   // Plus return value spill area size
-  return RoundUp(frame_data_size + sirt_size + SizeOfReturnValue(), kStackAlignment);
+  return RoundUp(frame_data_size + handle_scope_size + SizeOfReturnValue(), kStackAlignment);
 }
 
 size_t X86JniCallingConvention::OutArgSize() {
diff --git a/compiler/jni/quick/x86_64/calling_convention_x86_64.cc b/compiler/jni/quick/x86_64/calling_convention_x86_64.cc
index 52490e6..4871c87 100644
--- a/compiler/jni/quick/x86_64/calling_convention_x86_64.cc
+++ b/compiler/jni/quick/x86_64/calling_convention_x86_64.cc
@@ -140,10 +140,10 @@
 size_t X86_64JniCallingConvention::FrameSize() {
   // Method*, return address and callee save area size, local reference segment state
   size_t frame_data_size = (3 + CalleeSaveRegisters().size()) * kFramePointerSize;
-  // References plus link_ (pointer) and number_of_references_ (uint32_t) for SIRT header
-  size_t sirt_size = StackIndirectReferenceTable::GetAlignedSirtSizeTarget(kFramePointerSize, ReferenceCount());
+  // References plus link_ (pointer) and number_of_references_ (uint32_t) for HandleScope header
+  size_t handle_scope_size = HandleScope::GetAlignedHandleScopeSizeTarget(kFramePointerSize, ReferenceCount());
   // Plus return value spill area size
-  return RoundUp(frame_data_size + sirt_size + SizeOfReturnValue(), kStackAlignment);
+  return RoundUp(frame_data_size + handle_scope_size + SizeOfReturnValue(), kStackAlignment);
 }
 
 size_t X86_64JniCallingConvention::OutArgSize() {
diff --git a/compiler/oat_test.cc b/compiler/oat_test.cc
index 66972cb..558ff1f 100644
--- a/compiler/oat_test.cc
+++ b/compiler/oat_test.cc
@@ -153,7 +153,8 @@
       num_virtual_methods = it.NumVirtualMethods();
     }
     const char* descriptor = dex_file->GetClassDescriptor(class_def);
-    SirtRef<mirror::ClassLoader> loader(soa.Self(), nullptr);
+    StackHandleScope<1> hs(soa.Self());
+    auto loader(hs.NewHandle<mirror::ClassLoader>(nullptr));
     mirror::Class* klass = class_linker->FindClass(soa.Self(), descriptor, loader);
 
     const OatFile::OatClass oat_class = oat_dex_file->GetOatClass(i);
diff --git a/compiler/oat_writer.cc b/compiler/oat_writer.cc
index 39311d9..bace25c 100644
--- a/compiler/oat_writer.cc
+++ b/compiler/oat_writer.cc
@@ -33,7 +33,7 @@
 #include "output_stream.h"
 #include "safe_map.h"
 #include "scoped_thread_state_change.h"
-#include "sirt_ref-inl.h"
+#include "handle_scope-inl.h"
 #include "verifier/method_verifier.h"
 
 namespace art {
@@ -511,8 +511,9 @@
     InvokeType invoke_type = it.GetMethodInvokeType(dex_file_->GetClassDef(class_def_index_));
     // Unchecked as we hold mutator_lock_ on entry.
     ScopedObjectAccessUnchecked soa(Thread::Current());
-    SirtRef<mirror::DexCache> dex_cache(soa.Self(), linker->FindDexCache(*dex_file_));
-    SirtRef<mirror::ClassLoader> class_loader(soa.Self(), nullptr);
+    StackHandleScope<2> hs(soa.Self());
+    Handle<mirror::DexCache> dex_cache(hs.NewHandle(linker->FindDexCache(*dex_file_)));
+    auto class_loader = hs.NewHandle<mirror::ClassLoader>(nullptr);
     mirror::ArtMethod* method = linker->ResolveMethod(*dex_file_, it.GetMemberIndex(), dex_cache,
                                                       class_loader, nullptr, invoke_type);
     CHECK(method != NULL);
diff --git a/compiler/utils/arm/assembler_arm.cc b/compiler/utils/arm/assembler_arm.cc
index 5c839dd..64685c1 100644
--- a/compiler/utils/arm/assembler_arm.cc
+++ b/compiler/utils/arm/assembler_arm.cc
@@ -1752,53 +1752,53 @@
 #endif
 }
 
-void ArmAssembler::CreateSirtEntry(ManagedRegister mout_reg,
-                                   FrameOffset sirt_offset,
+void ArmAssembler::CreateHandleScopeEntry(ManagedRegister mout_reg,
+                                   FrameOffset handle_scope_offset,
                                    ManagedRegister min_reg, bool null_allowed) {
   ArmManagedRegister out_reg = mout_reg.AsArm();
   ArmManagedRegister in_reg = min_reg.AsArm();
   CHECK(in_reg.IsNoRegister() || in_reg.IsCoreRegister()) << in_reg;
   CHECK(out_reg.IsCoreRegister()) << out_reg;
   if (null_allowed) {
-    // Null values get a SIRT entry value of 0.  Otherwise, the SIRT entry is
-    // the address in the SIRT holding the reference.
+    // Null values get a handle scope entry value of 0.  Otherwise, the handle scope entry is
+    // the address in the handle scope holding the reference.
     // e.g. out_reg = (handle == 0) ? 0 : (SP+handle_offset)
     if (in_reg.IsNoRegister()) {
       LoadFromOffset(kLoadWord, out_reg.AsCoreRegister(),
-                     SP, sirt_offset.Int32Value());
+                     SP, handle_scope_offset.Int32Value());
       in_reg = out_reg;
     }
     cmp(in_reg.AsCoreRegister(), ShifterOperand(0));
     if (!out_reg.Equals(in_reg)) {
       LoadImmediate(out_reg.AsCoreRegister(), 0, EQ);
     }
-    AddConstant(out_reg.AsCoreRegister(), SP, sirt_offset.Int32Value(), NE);
+    AddConstant(out_reg.AsCoreRegister(), SP, handle_scope_offset.Int32Value(), NE);
   } else {
-    AddConstant(out_reg.AsCoreRegister(), SP, sirt_offset.Int32Value(), AL);
+    AddConstant(out_reg.AsCoreRegister(), SP, handle_scope_offset.Int32Value(), AL);
   }
 }
 
-void ArmAssembler::CreateSirtEntry(FrameOffset out_off,
-                                   FrameOffset sirt_offset,
+void ArmAssembler::CreateHandleScopeEntry(FrameOffset out_off,
+                                   FrameOffset handle_scope_offset,
                                    ManagedRegister mscratch,
                                    bool null_allowed) {
   ArmManagedRegister scratch = mscratch.AsArm();
   CHECK(scratch.IsCoreRegister()) << scratch;
   if (null_allowed) {
     LoadFromOffset(kLoadWord, scratch.AsCoreRegister(), SP,
-                   sirt_offset.Int32Value());
-    // Null values get a SIRT entry value of 0.  Otherwise, the sirt entry is
-    // the address in the SIRT holding the reference.
-    // e.g. scratch = (scratch == 0) ? 0 : (SP+sirt_offset)
+                   handle_scope_offset.Int32Value());
+    // Null values get a handle scope entry value of 0.  Otherwise, the handle scope entry is
+    // the address in the handle scope holding the reference.
+    // e.g. scratch = (scratch == 0) ? 0 : (SP+handle_scope_offset)
     cmp(scratch.AsCoreRegister(), ShifterOperand(0));
-    AddConstant(scratch.AsCoreRegister(), SP, sirt_offset.Int32Value(), NE);
+    AddConstant(scratch.AsCoreRegister(), SP, handle_scope_offset.Int32Value(), NE);
   } else {
-    AddConstant(scratch.AsCoreRegister(), SP, sirt_offset.Int32Value(), AL);
+    AddConstant(scratch.AsCoreRegister(), SP, handle_scope_offset.Int32Value(), AL);
   }
   StoreToOffset(kStoreWord, scratch.AsCoreRegister(), SP, out_off.Int32Value());
 }
 
-void ArmAssembler::LoadReferenceFromSirt(ManagedRegister mout_reg,
+void ArmAssembler::LoadReferenceFromHandleScope(ManagedRegister mout_reg,
                                          ManagedRegister min_reg) {
   ArmManagedRegister out_reg = mout_reg.AsArm();
   ArmManagedRegister in_reg = min_reg.AsArm();
diff --git a/compiler/utils/arm/assembler_arm.h b/compiler/utils/arm/assembler_arm.h
index f5be04a..396e603 100644
--- a/compiler/utils/arm/assembler_arm.h
+++ b/compiler/utils/arm/assembler_arm.h
@@ -521,20 +521,20 @@
   void GetCurrentThread(ManagedRegister tr) OVERRIDE;
   void GetCurrentThread(FrameOffset dest_offset, ManagedRegister scratch) OVERRIDE;
 
-  // Set up out_reg to hold a Object** into the SIRT, or to be NULL if the
+  // Set up out_reg to hold a Object** into the handle scope, or to be NULL if the
   // value is null and null_allowed. in_reg holds a possibly stale reference
-  // that can be used to avoid loading the SIRT entry to see if the value is
+  // that can be used to avoid loading the handle scope entry to see if the value is
   // NULL.
-  void CreateSirtEntry(ManagedRegister out_reg, FrameOffset sirt_offset, ManagedRegister in_reg,
+  void CreateHandleScopeEntry(ManagedRegister out_reg, FrameOffset handlescope_offset, ManagedRegister in_reg,
                        bool null_allowed) OVERRIDE;
 
-  // Set up out_off to hold a Object** into the SIRT, or to be NULL if the
+  // Set up out_off to hold a Object** into the handle scope, or to be NULL if the
   // value is null and null_allowed.
-  void CreateSirtEntry(FrameOffset out_off, FrameOffset sirt_offset, ManagedRegister scratch,
+  void CreateHandleScopeEntry(FrameOffset out_off, FrameOffset handlescope_offset, ManagedRegister scratch,
                        bool null_allowed) OVERRIDE;
 
-  // src holds a SIRT entry (Object**) load this into dst
-  void LoadReferenceFromSirt(ManagedRegister dst, ManagedRegister src) OVERRIDE;
+  // src holds a handle scope entry (Object**) load this into dst
+  void LoadReferenceFromHandleScope(ManagedRegister dst, ManagedRegister src) OVERRIDE;
 
   // Heap::VerifyObject on src. In some cases (such as a reference to this) we
   // know that src may not be null.
diff --git a/compiler/utils/arm64/assembler_arm64.cc b/compiler/utils/arm64/assembler_arm64.cc
index f486b3c..27188b2 100644
--- a/compiler/utils/arm64/assembler_arm64.cc
+++ b/compiler/utils/arm64/assembler_arm64.cc
@@ -539,52 +539,52 @@
   UNIMPLEMENTED(FATAL) << "Unimplemented Call() variant";
 }
 
-void Arm64Assembler::CreateSirtEntry(ManagedRegister m_out_reg, FrameOffset sirt_offs,
+void Arm64Assembler::CreateHandleScopeEntry(ManagedRegister m_out_reg, FrameOffset handle_scope_offs,
                                      ManagedRegister m_in_reg, bool null_allowed) {
   Arm64ManagedRegister out_reg = m_out_reg.AsArm64();
   Arm64ManagedRegister in_reg = m_in_reg.AsArm64();
-  // For now we only hold stale sirt entries in x registers.
+  // For now we only hold stale handle scope entries in x registers.
   CHECK(in_reg.IsNoRegister() || in_reg.IsCoreRegister()) << in_reg;
   CHECK(out_reg.IsCoreRegister()) << out_reg;
   if (null_allowed) {
-    // Null values get a SIRT entry value of 0.  Otherwise, the SIRT entry is
-    // the address in the SIRT holding the reference.
+    // Null values get a handle scope entry value of 0.  Otherwise, the handle scope entry is
+    // the address in the handle scope holding the reference.
     // e.g. out_reg = (handle == 0) ? 0 : (SP+handle_offset)
     if (in_reg.IsNoRegister()) {
       LoadWFromOffset(kLoadWord, out_reg.AsOverlappingCoreRegisterLow(), SP,
-                      sirt_offs.Int32Value());
+                      handle_scope_offs.Int32Value());
       in_reg = out_reg;
     }
     ___ Cmp(reg_w(in_reg.AsOverlappingCoreRegisterLow()), 0);
     if (!out_reg.Equals(in_reg)) {
       LoadImmediate(out_reg.AsCoreRegister(), 0, EQ);
     }
-    AddConstant(out_reg.AsCoreRegister(), SP, sirt_offs.Int32Value(), NE);
+    AddConstant(out_reg.AsCoreRegister(), SP, handle_scope_offs.Int32Value(), NE);
   } else {
-    AddConstant(out_reg.AsCoreRegister(), SP, sirt_offs.Int32Value(), AL);
+    AddConstant(out_reg.AsCoreRegister(), SP, handle_scope_offs.Int32Value(), AL);
   }
 }
 
-void Arm64Assembler::CreateSirtEntry(FrameOffset out_off, FrameOffset sirt_offset,
+void Arm64Assembler::CreateHandleScopeEntry(FrameOffset out_off, FrameOffset handle_scope_offset,
                                      ManagedRegister m_scratch, bool null_allowed) {
   Arm64ManagedRegister scratch = m_scratch.AsArm64();
   CHECK(scratch.IsCoreRegister()) << scratch;
   if (null_allowed) {
     LoadWFromOffset(kLoadWord, scratch.AsOverlappingCoreRegisterLow(), SP,
-                    sirt_offset.Int32Value());
-    // Null values get a SIRT entry value of 0.  Otherwise, the sirt entry is
-    // the address in the SIRT holding the reference.
-    // e.g. scratch = (scratch == 0) ? 0 : (SP+sirt_offset)
+                    handle_scope_offset.Int32Value());
+    // Null values get a handle scope entry value of 0.  Otherwise, the handle scope entry is
+    // the address in the handle scope holding the reference.
+    // e.g. scratch = (scratch == 0) ? 0 : (SP+handle_scope_offset)
     ___ Cmp(reg_w(scratch.AsOverlappingCoreRegisterLow()), 0);
     // Move this logic in add constants with flags.
-    AddConstant(scratch.AsCoreRegister(), SP, sirt_offset.Int32Value(), NE);
+    AddConstant(scratch.AsCoreRegister(), SP, handle_scope_offset.Int32Value(), NE);
   } else {
-    AddConstant(scratch.AsCoreRegister(), SP, sirt_offset.Int32Value(), AL);
+    AddConstant(scratch.AsCoreRegister(), SP, handle_scope_offset.Int32Value(), AL);
   }
   StoreToOffset(scratch.AsCoreRegister(), SP, out_off.Int32Value());
 }
 
-void Arm64Assembler::LoadReferenceFromSirt(ManagedRegister m_out_reg,
+void Arm64Assembler::LoadReferenceFromHandleScope(ManagedRegister m_out_reg,
                                            ManagedRegister m_in_reg) {
   Arm64ManagedRegister out_reg = m_out_reg.AsArm64();
   Arm64ManagedRegister in_reg = m_in_reg.AsArm64();
diff --git a/compiler/utils/arm64/assembler_arm64.h b/compiler/utils/arm64/assembler_arm64.h
index 583150c..c866b29 100644
--- a/compiler/utils/arm64/assembler_arm64.h
+++ b/compiler/utils/arm64/assembler_arm64.h
@@ -161,20 +161,20 @@
   void GetCurrentThread(ManagedRegister tr) OVERRIDE;
   void GetCurrentThread(FrameOffset dest_offset, ManagedRegister scratch) OVERRIDE;
 
-  // Set up out_reg to hold a Object** into the SIRT, or to be NULL if the
+  // Set up out_reg to hold a Object** into the handle scope, or to be NULL if the
   // value is null and null_allowed. in_reg holds a possibly stale reference
-  // that can be used to avoid loading the SIRT entry to see if the value is
+  // that can be used to avoid loading the handle scope entry to see if the value is
   // NULL.
-  void CreateSirtEntry(ManagedRegister out_reg, FrameOffset sirt_offset,
+  void CreateHandleScopeEntry(ManagedRegister out_reg, FrameOffset handlescope_offset,
                        ManagedRegister in_reg, bool null_allowed) OVERRIDE;
 
-  // Set up out_off to hold a Object** into the SIRT, or to be NULL if the
+  // Set up out_off to hold a Object** into the handle scope, or to be NULL if the
   // value is null and null_allowed.
-  void CreateSirtEntry(FrameOffset out_off, FrameOffset sirt_offset,
+  void CreateHandleScopeEntry(FrameOffset out_off, FrameOffset handlescope_offset,
                        ManagedRegister scratch, bool null_allowed) OVERRIDE;
 
-  // src holds a SIRT entry (Object**) load this into dst.
-  void LoadReferenceFromSirt(ManagedRegister dst, ManagedRegister src) OVERRIDE;
+  // src holds a handle scope entry (Object**) load this into dst.
+  void LoadReferenceFromHandleScope(ManagedRegister dst, ManagedRegister src) OVERRIDE;
 
   // Heap::VerifyObject on src. In some cases (such as a reference to this) we
   // know that src may not be null.
diff --git a/compiler/utils/assembler.h b/compiler/utils/assembler.h
index 219c87f..19239e1 100644
--- a/compiler/utils/assembler.h
+++ b/compiler/utils/assembler.h
@@ -453,20 +453,20 @@
   virtual void GetCurrentThread(FrameOffset dest_offset,
                                 ManagedRegister scratch) = 0;
 
-  // Set up out_reg to hold a Object** into the SIRT, or to be NULL if the
+  // Set up out_reg to hold a Object** into the handle scope, or to be NULL if the
   // value is null and null_allowed. in_reg holds a possibly stale reference
-  // that can be used to avoid loading the SIRT entry to see if the value is
+  // that can be used to avoid loading the handle scope entry to see if the value is
   // NULL.
-  virtual void CreateSirtEntry(ManagedRegister out_reg, FrameOffset sirt_offset,
+  virtual void CreateHandleScopeEntry(ManagedRegister out_reg, FrameOffset handlescope_offset,
                                ManagedRegister in_reg, bool null_allowed) = 0;
 
-  // Set up out_off to hold a Object** into the SIRT, or to be NULL if the
+  // Set up out_off to hold a Object** into the handle scope, or to be NULL if the
   // value is null and null_allowed.
-  virtual void CreateSirtEntry(FrameOffset out_off, FrameOffset sirt_offset,
+  virtual void CreateHandleScopeEntry(FrameOffset out_off, FrameOffset handlescope_offset,
                                ManagedRegister scratch, bool null_allowed) = 0;
 
-  // src holds a SIRT entry (Object**) load this into dst
-  virtual void LoadReferenceFromSirt(ManagedRegister dst,
+  // src holds a handle scope entry (Object**) load this into dst
+  virtual void LoadReferenceFromHandleScope(ManagedRegister dst,
                                      ManagedRegister src) = 0;
 
   // Heap::VerifyObject on src. In some cases (such as a reference to this) we
diff --git a/compiler/utils/mips/assembler_mips.cc b/compiler/utils/mips/assembler_mips.cc
index 9001f8a..8001dcd 100644
--- a/compiler/utils/mips/assembler_mips.cc
+++ b/compiler/utils/mips/assembler_mips.cc
@@ -827,8 +827,8 @@
   UNIMPLEMENTED(FATAL) << "no mips implementation";
 }
 
-void MipsAssembler::CreateSirtEntry(ManagedRegister mout_reg,
-                                    FrameOffset sirt_offset,
+void MipsAssembler::CreateHandleScopeEntry(ManagedRegister mout_reg,
+                                    FrameOffset handle_scope_offset,
                                     ManagedRegister min_reg, bool null_allowed) {
   MipsManagedRegister out_reg = mout_reg.AsMips();
   MipsManagedRegister in_reg = min_reg.AsMips();
@@ -836,27 +836,27 @@
   CHECK(out_reg.IsCoreRegister()) << out_reg;
   if (null_allowed) {
     Label null_arg;
-    // Null values get a SIRT entry value of 0.  Otherwise, the SIRT entry is
-    // the address in the SIRT holding the reference.
+    // Null values get a handle scope entry value of 0.  Otherwise, the handle scope entry is
+    // the address in the handle scope holding the reference.
     // e.g. out_reg = (handle == 0) ? 0 : (SP+handle_offset)
     if (in_reg.IsNoRegister()) {
       LoadFromOffset(kLoadWord, out_reg.AsCoreRegister(),
-                     SP, sirt_offset.Int32Value());
+                     SP, handle_scope_offset.Int32Value());
       in_reg = out_reg;
     }
     if (!out_reg.Equals(in_reg)) {
       LoadImmediate(out_reg.AsCoreRegister(), 0);
     }
     EmitBranch(in_reg.AsCoreRegister(), ZERO, &null_arg, true);
-    AddConstant(out_reg.AsCoreRegister(), SP, sirt_offset.Int32Value());
+    AddConstant(out_reg.AsCoreRegister(), SP, handle_scope_offset.Int32Value());
     Bind(&null_arg, false);
   } else {
-    AddConstant(out_reg.AsCoreRegister(), SP, sirt_offset.Int32Value());
+    AddConstant(out_reg.AsCoreRegister(), SP, handle_scope_offset.Int32Value());
   }
 }
 
-void MipsAssembler::CreateSirtEntry(FrameOffset out_off,
-                                    FrameOffset sirt_offset,
+void MipsAssembler::CreateHandleScopeEntry(FrameOffset out_off,
+                                    FrameOffset handle_scope_offset,
                                     ManagedRegister mscratch,
                                     bool null_allowed) {
   MipsManagedRegister scratch = mscratch.AsMips();
@@ -864,21 +864,21 @@
   if (null_allowed) {
     Label null_arg;
     LoadFromOffset(kLoadWord, scratch.AsCoreRegister(), SP,
-                   sirt_offset.Int32Value());
-    // Null values get a SIRT entry value of 0.  Otherwise, the sirt entry is
-    // the address in the SIRT holding the reference.
-    // e.g. scratch = (scratch == 0) ? 0 : (SP+sirt_offset)
+                   handle_scope_offset.Int32Value());
+    // Null values get a handle scope entry value of 0.  Otherwise, the handle scope entry is
+    // the address in the handle scope holding the reference.
+    // e.g. scratch = (scratch == 0) ? 0 : (SP+handle_scope_offset)
     EmitBranch(scratch.AsCoreRegister(), ZERO, &null_arg, true);
-    AddConstant(scratch.AsCoreRegister(), SP, sirt_offset.Int32Value());
+    AddConstant(scratch.AsCoreRegister(), SP, handle_scope_offset.Int32Value());
     Bind(&null_arg, false);
   } else {
-    AddConstant(scratch.AsCoreRegister(), SP, sirt_offset.Int32Value());
+    AddConstant(scratch.AsCoreRegister(), SP, handle_scope_offset.Int32Value());
   }
   StoreToOffset(kStoreWord, scratch.AsCoreRegister(), SP, out_off.Int32Value());
 }
 
-// Given a SIRT entry, load the associated reference.
-void MipsAssembler::LoadReferenceFromSirt(ManagedRegister mout_reg,
+// Given a handle scope entry, load the associated reference.
+void MipsAssembler::LoadReferenceFromHandleScope(ManagedRegister mout_reg,
                                           ManagedRegister min_reg) {
   MipsManagedRegister out_reg = mout_reg.AsMips();
   MipsManagedRegister in_reg = min_reg.AsMips();
diff --git a/compiler/utils/mips/assembler_mips.h b/compiler/utils/mips/assembler_mips.h
index 75ee8b9..216cb41 100644
--- a/compiler/utils/mips/assembler_mips.h
+++ b/compiler/utils/mips/assembler_mips.h
@@ -238,20 +238,20 @@
   void GetCurrentThread(ManagedRegister tr) OVERRIDE;
   void GetCurrentThread(FrameOffset dest_offset, ManagedRegister mscratch) OVERRIDE;
 
-  // Set up out_reg to hold a Object** into the SIRT, or to be NULL if the
+  // Set up out_reg to hold a Object** into the handle scope, or to be NULL if the
   // value is null and null_allowed. in_reg holds a possibly stale reference
-  // that can be used to avoid loading the SIRT entry to see if the value is
+  // that can be used to avoid loading the handle scope entry to see if the value is
   // NULL.
-  void CreateSirtEntry(ManagedRegister out_reg, FrameOffset sirt_offset, ManagedRegister in_reg,
+  void CreateHandleScopeEntry(ManagedRegister out_reg, FrameOffset handlescope_offset, ManagedRegister in_reg,
                        bool null_allowed) OVERRIDE;
 
-  // Set up out_off to hold a Object** into the SIRT, or to be NULL if the
+  // Set up out_off to hold a Object** into the handle scope, or to be NULL if the
   // value is null and null_allowed.
-  void CreateSirtEntry(FrameOffset out_off, FrameOffset sirt_offset, ManagedRegister mscratch,
+  void CreateHandleScopeEntry(FrameOffset out_off, FrameOffset handlescope_offset, ManagedRegister mscratch,
                        bool null_allowed) OVERRIDE;
 
-  // src holds a SIRT entry (Object**) load this into dst
-  void LoadReferenceFromSirt(ManagedRegister dst, ManagedRegister src) OVERRIDE;
+  // src holds a handle scope entry (Object**) load this into dst
+  void LoadReferenceFromHandleScope(ManagedRegister dst, ManagedRegister src) OVERRIDE;
 
   // Heap::VerifyObject on src. In some cases (such as a reference to this) we
   // know that src may not be null.
diff --git a/compiler/utils/x86/assembler_x86.cc b/compiler/utils/x86/assembler_x86.cc
index 6a3efc5..0791c63 100644
--- a/compiler/utils/x86/assembler_x86.cc
+++ b/compiler/utils/x86/assembler_x86.cc
@@ -1727,8 +1727,8 @@
 #endif
 }
 
-void X86Assembler::CreateSirtEntry(ManagedRegister mout_reg,
-                                   FrameOffset sirt_offset,
+void X86Assembler::CreateHandleScopeEntry(ManagedRegister mout_reg,
+                                   FrameOffset handle_scope_offset,
                                    ManagedRegister min_reg, bool null_allowed) {
   X86ManagedRegister out_reg = mout_reg.AsX86();
   X86ManagedRegister in_reg = min_reg.AsX86();
@@ -1742,34 +1742,34 @@
     }
     testl(in_reg.AsCpuRegister(), in_reg.AsCpuRegister());
     j(kZero, &null_arg);
-    leal(out_reg.AsCpuRegister(), Address(ESP, sirt_offset));
+    leal(out_reg.AsCpuRegister(), Address(ESP, handle_scope_offset));
     Bind(&null_arg);
   } else {
-    leal(out_reg.AsCpuRegister(), Address(ESP, sirt_offset));
+    leal(out_reg.AsCpuRegister(), Address(ESP, handle_scope_offset));
   }
 }
 
-void X86Assembler::CreateSirtEntry(FrameOffset out_off,
-                                   FrameOffset sirt_offset,
+void X86Assembler::CreateHandleScopeEntry(FrameOffset out_off,
+                                   FrameOffset handle_scope_offset,
                                    ManagedRegister mscratch,
                                    bool null_allowed) {
   X86ManagedRegister scratch = mscratch.AsX86();
   CHECK(scratch.IsCpuRegister());
   if (null_allowed) {
     Label null_arg;
-    movl(scratch.AsCpuRegister(), Address(ESP, sirt_offset));
+    movl(scratch.AsCpuRegister(), Address(ESP, handle_scope_offset));
     testl(scratch.AsCpuRegister(), scratch.AsCpuRegister());
     j(kZero, &null_arg);
-    leal(scratch.AsCpuRegister(), Address(ESP, sirt_offset));
+    leal(scratch.AsCpuRegister(), Address(ESP, handle_scope_offset));
     Bind(&null_arg);
   } else {
-    leal(scratch.AsCpuRegister(), Address(ESP, sirt_offset));
+    leal(scratch.AsCpuRegister(), Address(ESP, handle_scope_offset));
   }
   Store(out_off, scratch, 4);
 }
 
-// Given a SIRT entry, load the associated reference.
-void X86Assembler::LoadReferenceFromSirt(ManagedRegister mout_reg,
+// Given a handle scope entry, load the associated reference.
+void X86Assembler::LoadReferenceFromHandleScope(ManagedRegister mout_reg,
                                          ManagedRegister min_reg) {
   X86ManagedRegister out_reg = mout_reg.AsX86();
   X86ManagedRegister in_reg = min_reg.AsX86();
diff --git a/compiler/utils/x86/assembler_x86.h b/compiler/utils/x86/assembler_x86.h
index 057c80a..2fc6049 100644
--- a/compiler/utils/x86/assembler_x86.h
+++ b/compiler/utils/x86/assembler_x86.h
@@ -541,20 +541,20 @@
   void GetCurrentThread(ManagedRegister tr) OVERRIDE;
   void GetCurrentThread(FrameOffset dest_offset, ManagedRegister scratch) OVERRIDE;
 
-  // Set up out_reg to hold a Object** into the SIRT, or to be NULL if the
+  // Set up out_reg to hold a Object** into the handle scope, or to be NULL if the
   // value is null and null_allowed. in_reg holds a possibly stale reference
-  // that can be used to avoid loading the SIRT entry to see if the value is
+  // that can be used to avoid loading the handle scope entry to see if the value is
   // NULL.
-  void CreateSirtEntry(ManagedRegister out_reg, FrameOffset sirt_offset, ManagedRegister in_reg,
+  void CreateHandleScopeEntry(ManagedRegister out_reg, FrameOffset handlescope_offset, ManagedRegister in_reg,
                        bool null_allowed) OVERRIDE;
 
-  // Set up out_off to hold a Object** into the SIRT, or to be NULL if the
+  // Set up out_off to hold a Object** into the handle scope, or to be NULL if the
   // value is null and null_allowed.
-  void CreateSirtEntry(FrameOffset out_off, FrameOffset sirt_offset, ManagedRegister scratch,
+  void CreateHandleScopeEntry(FrameOffset out_off, FrameOffset handlescope_offset, ManagedRegister scratch,
                        bool null_allowed) OVERRIDE;
 
-  // src holds a SIRT entry (Object**) load this into dst
-  void LoadReferenceFromSirt(ManagedRegister dst, ManagedRegister src) OVERRIDE;
+  // src holds a handle scope entry (Object**) load this into dst
+  void LoadReferenceFromHandleScope(ManagedRegister dst, ManagedRegister src) OVERRIDE;
 
   // Heap::VerifyObject on src. In some cases (such as a reference to this) we
   // know that src may not be null.
diff --git a/compiler/utils/x86_64/assembler_x86_64.cc b/compiler/utils/x86_64/assembler_x86_64.cc
index 8eaeae1..0ede875 100644
--- a/compiler/utils/x86_64/assembler_x86_64.cc
+++ b/compiler/utils/x86_64/assembler_x86_64.cc
@@ -1989,8 +1989,8 @@
 #endif
 }
 
-void X86_64Assembler::CreateSirtEntry(ManagedRegister mout_reg,
-                                   FrameOffset sirt_offset,
+void X86_64Assembler::CreateHandleScopeEntry(ManagedRegister mout_reg,
+                                   FrameOffset handle_scope_offset,
                                    ManagedRegister min_reg, bool null_allowed) {
   X86_64ManagedRegister out_reg = mout_reg.AsX86_64();
   X86_64ManagedRegister in_reg = min_reg.AsX86_64();
@@ -1998,7 +1998,7 @@
     // Use out_reg as indicator of NULL
     in_reg = out_reg;
     // TODO: movzwl
-    movl(in_reg.AsCpuRegister(), Address(CpuRegister(RSP), sirt_offset));
+    movl(in_reg.AsCpuRegister(), Address(CpuRegister(RSP), handle_scope_offset));
   }
   CHECK(in_reg.IsCpuRegister());
   CHECK(out_reg.IsCpuRegister());
@@ -2010,34 +2010,34 @@
     }
     testl(in_reg.AsCpuRegister(), in_reg.AsCpuRegister());
     j(kZero, &null_arg);
-    leaq(out_reg.AsCpuRegister(), Address(CpuRegister(RSP), sirt_offset));
+    leaq(out_reg.AsCpuRegister(), Address(CpuRegister(RSP), handle_scope_offset));
     Bind(&null_arg);
   } else {
-    leaq(out_reg.AsCpuRegister(), Address(CpuRegister(RSP), sirt_offset));
+    leaq(out_reg.AsCpuRegister(), Address(CpuRegister(RSP), handle_scope_offset));
   }
 }
 
-void X86_64Assembler::CreateSirtEntry(FrameOffset out_off,
-                                   FrameOffset sirt_offset,
+void X86_64Assembler::CreateHandleScopeEntry(FrameOffset out_off,
+                                   FrameOffset handle_scope_offset,
                                    ManagedRegister mscratch,
                                    bool null_allowed) {
   X86_64ManagedRegister scratch = mscratch.AsX86_64();
   CHECK(scratch.IsCpuRegister());
   if (null_allowed) {
     Label null_arg;
-    movl(scratch.AsCpuRegister(), Address(CpuRegister(RSP), sirt_offset));
+    movl(scratch.AsCpuRegister(), Address(CpuRegister(RSP), handle_scope_offset));
     testl(scratch.AsCpuRegister(), scratch.AsCpuRegister());
     j(kZero, &null_arg);
-    leaq(scratch.AsCpuRegister(), Address(CpuRegister(RSP), sirt_offset));
+    leaq(scratch.AsCpuRegister(), Address(CpuRegister(RSP), handle_scope_offset));
     Bind(&null_arg);
   } else {
-    leaq(scratch.AsCpuRegister(), Address(CpuRegister(RSP), sirt_offset));
+    leaq(scratch.AsCpuRegister(), Address(CpuRegister(RSP), handle_scope_offset));
   }
   Store(out_off, scratch, 8);
 }
 
-// Given a SIRT entry, load the associated reference.
-void X86_64Assembler::LoadReferenceFromSirt(ManagedRegister mout_reg,
+// Given a handle scope entry, load the associated reference.
+void X86_64Assembler::LoadReferenceFromHandleScope(ManagedRegister mout_reg,
                                          ManagedRegister min_reg) {
   X86_64ManagedRegister out_reg = mout_reg.AsX86_64();
   X86_64ManagedRegister in_reg = min_reg.AsX86_64();
diff --git a/compiler/utils/x86_64/assembler_x86_64.h b/compiler/utils/x86_64/assembler_x86_64.h
index 87fb359..548d379 100644
--- a/compiler/utils/x86_64/assembler_x86_64.h
+++ b/compiler/utils/x86_64/assembler_x86_64.h
@@ -566,20 +566,20 @@
   void GetCurrentThread(ManagedRegister tr) OVERRIDE;
   void GetCurrentThread(FrameOffset dest_offset, ManagedRegister scratch) OVERRIDE;
 
-  // Set up out_reg to hold a Object** into the SIRT, or to be NULL if the
+  // Set up out_reg to hold a Object** into the handle scope, or to be NULL if the
   // value is null and null_allowed. in_reg holds a possibly stale reference
-  // that can be used to avoid loading the SIRT entry to see if the value is
+  // that can be used to avoid loading the handle scope entry to see if the value is
   // NULL.
-  void CreateSirtEntry(ManagedRegister out_reg, FrameOffset sirt_offset, ManagedRegister in_reg,
+  void CreateHandleScopeEntry(ManagedRegister out_reg, FrameOffset handlescope_offset, ManagedRegister in_reg,
                        bool null_allowed) OVERRIDE;
 
-  // Set up out_off to hold a Object** into the SIRT, or to be NULL if the
+  // Set up out_off to hold a Object** into the handle scope, or to be NULL if the
   // value is null and null_allowed.
-  void CreateSirtEntry(FrameOffset out_off, FrameOffset sirt_offset, ManagedRegister scratch,
+  void CreateHandleScopeEntry(FrameOffset out_off, FrameOffset handlescope_offset, ManagedRegister scratch,
                        bool null_allowed) OVERRIDE;
 
-  // src holds a SIRT entry (Object**) load this into dst
-  virtual void LoadReferenceFromSirt(ManagedRegister dst,
+  // src holds a handle scope entry (Object**) load this into dst
+  virtual void LoadReferenceFromHandleScope(ManagedRegister dst,
                                      ManagedRegister src);
 
   // Heap::VerifyObject on src. In some cases (such as a reference to this) we