diff --git a/Android.mk b/Android.mk
index 145f8b0..27cce22 100644
--- a/Android.mk
+++ b/Android.mk
@@ -305,7 +305,7 @@
 # oatdump targets
 
 .PHONY: dump-oat
-dump-oat: dump-oat-core dump-oat-boot dump-oat-Calculator
+dump-oat: dump-oat-core dump-oat-boot
 
 .PHONY: dump-oat-core
 dump-oat-core: dump-oat-core-host dump-oat-core-target
diff --git a/build/Android.common.mk b/build/Android.common.mk
index 2472158..7faf452 100644
--- a/build/Android.common.mk
+++ b/build/Android.common.mk
@@ -246,6 +246,7 @@
 	src/thread.cc \
 	src/thread_list.cc \
 	src/thread_pool.cc \
+	src/throw_location.cc \
 	src/trace.cc \
 	src/utf.cc \
 	src/utils.cc \
@@ -263,7 +264,6 @@
 	src/oat/runtime/context.cc \
 	src/oat/runtime/support_alloc.cc \
 	src/oat/runtime/support_cast.cc \
-	src/oat/runtime/support_debug.cc \
 	src/oat/runtime/support_deoptimize.cc \
 	src/oat/runtime/support_dexcache.cc \
 	src/oat/runtime/support_field.cc \
diff --git a/src/base/mutex-inl.h b/src/base/mutex-inl.h
index 3cb43a8..f911054 100644
--- a/src/base/mutex-inl.h
+++ b/src/base/mutex-inl.h
@@ -97,8 +97,9 @@
       BaseMutex* held_mutex = self->GetHeldMutex(static_cast<LockLevel>(i));
       if (UNLIKELY(held_mutex != NULL)) {
         LOG(ERROR) << "Lock level violation: holding \"" << held_mutex->name_ << "\" "
-                   << "(level " << LockLevel(i) << ") while locking \"" << name_ << "\" "
-                   << "(level " << level_ << ")";
+                   << "(level " << LockLevel(i) << " - " << i
+                   << ") while locking \"" << name_ << "\" "
+                   << "(level " << level_ << " - " << static_cast<int>(level_) << ")";
         if (i > kAbortLock) {
           // Only abort in the check below if this is more than abort level lock.
           bad_mutexes_held = true;
diff --git a/src/check_jni.cc b/src/check_jni.cc
index 57ce432..30d5099 100644
--- a/src/check_jni.cc
+++ b/src/check_jni.cc
@@ -44,7 +44,7 @@
 static void JniAbort(const char* jni_function_name, const char* msg) {
   Thread* self = Thread::Current();
   ScopedObjectAccess soa(self);
-  mirror::AbstractMethod* current_method = self->GetCurrentMethod();
+  mirror::AbstractMethod* current_method = self->GetCurrentMethod(NULL);
 
   std::ostringstream os;
   os << "JNI DETECTED ERROR IN APPLICATION: " << msg;
@@ -401,8 +401,7 @@
    *
    * Use the kFlag_NullableUtf flag where 'u' field(s) are nullable.
    */
-  void Check(bool entry, const char* fmt0, ...)
-      SHARED_LOCKS_REQUIRED (Locks::mutator_lock_) {
+  void Check(bool entry, const char* fmt0, ...) SHARED_LOCKS_REQUIRED (Locks::mutator_lock_) {
     va_list ap;
 
     const mirror::AbstractMethod* traceMethod = NULL;
@@ -411,7 +410,7 @@
       // use DetachCurrentThread or GetEnv on a thread that's not yet attached.
       Thread* self = Thread::Current();
       if ((flags_ & kFlag_Invocation) == 0 || self != NULL) {
-        traceMethod = self->GetCurrentMethod();
+        traceMethod = self->GetCurrentMethod(NULL);
       }
     }
 
@@ -812,14 +811,19 @@
     // Verify that, if an exception has been raised, the native code doesn't
     // make any JNI calls other than the Exception* methods.
     if ((flags & kFlag_ExcepOkay) == 0 && self->IsExceptionPending()) {
-      std::string type(PrettyTypeOf(self->GetException()));
+      ThrowLocation throw_location;
+      mirror::Throwable* exception = self->GetException(&throw_location);
+      std::string type(PrettyTypeOf(exception));
       // TODO: write native code that doesn't require allocation for dumping an exception.
       // TODO: do we care any more? art always dumps pending exceptions on aborting threads.
-      if (type != "java.lang.OutOfMemoryError") {
-        JniAbortF(function_name_, "JNI %s called with pending exception: %s",
-                  function_name_, type.c_str(), jniGetStackTrace(soa_.Env()).c_str());
+      bool with_stack_trace = (type != "java.lang.OutOfMemoryError");
+      if (with_stack_trace) {
+        JniAbortF(function_name_, "JNI %s called with pending exception '%s' thrown in %s\n%s",
+                  function_name_, type.c_str(), throw_location.Dump().c_str(),
+                  jniGetStackTrace(soa_.Env()).c_str());
       } else {
-        JniAbortF(function_name_, "JNI %s called with %s pending", function_name_, type.c_str());
+        JniAbortF(function_name_, "JNI %s called with pending exception '%s' thrown in %s",
+                  function_name_, type.c_str(), throw_location.Dump().c_str());
       }
       return;
     }
@@ -1772,7 +1776,7 @@
       JniAbortF(__FUNCTION__, "non-nullable address is NULL");
     }
     if (capacity <= 0) {
-      JniAbortF(__FUNCTION__, "capacity must be greater than 0: %d", capacity);
+      JniAbortF(__FUNCTION__, "capacity must be greater than 0: %lld", capacity);
     }
     return CHECK_JNI_EXIT("L", baseEnv(env)->NewDirectByteBuffer(env, address, capacity));
   }
diff --git a/src/class_linker.cc b/src/class_linker.cc
index a9e17b2..4774c63 100644
--- a/src/class_linker.cc
+++ b/src/class_linker.cc
@@ -80,51 +80,9 @@
 static void ThrowNoClassDefFoundError(const char* fmt, ...) {
   va_list args;
   va_start(args, fmt);
-  Thread::Current()->ThrowNewExceptionV("Ljava/lang/NoClassDefFoundError;", fmt, args);
-  va_end(args);
-}
-
-static void ThrowClassFormatError(const char* fmt, ...)
-    __attribute__((__format__(__printf__, 1, 2)))
-    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
-static void ThrowClassFormatError(const char* fmt, ...) {
-  va_list args;
-  va_start(args, fmt);
-  Thread::Current()->ThrowNewExceptionV("Ljava/lang/ClassFormatError;", fmt, args);
-  va_end(args);
-}
-
-static void ThrowLinkageError(const char* fmt, ...)
-    __attribute__((__format__(__printf__, 1, 2)))
-    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
-static void ThrowLinkageError(const char* fmt, ...) {
-  va_list args;
-  va_start(args, fmt);
-  Thread::Current()->ThrowNewExceptionV("Ljava/lang/LinkageError;", fmt, args);
-  va_end(args);
-}
-
-static void ThrowNoSuchFieldError(const StringPiece& scope, mirror::Class* c, const StringPiece& type,
-                                  const StringPiece& name)
-    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
-  ClassHelper kh(c);
-  std::ostringstream msg;
-  msg << "No " << scope << "field " << name << " of type " << type
-      << " in class " << kh.GetDescriptor() << " or its superclasses";
-  std::string location(kh.GetLocation());
-  if (!location.empty()) {
-    msg << " (defined in " << location << ")";
-  }
-  Thread::Current()->ThrowNewException("Ljava/lang/NoSuchFieldError;", msg.str().c_str());
-}
-
-static void ThrowNullPointerException(const char* fmt, ...)
-    __attribute__((__format__(__printf__, 1, 2)))
-    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
-static void ThrowNullPointerException(const char* fmt, ...) {
-  va_list args;
-  va_start(args, fmt);
-  Thread::Current()->ThrowNewExceptionV("Ljava/lang/NullPointerException;", fmt, args);
+  Thread* self = Thread::Current();
+  ThrowLocation throw_location = self->GetCurrentLocationForThrow();
+  self->ThrowNewExceptionV(throw_location, "Ljava/lang/NoClassDefFoundError;", fmt, args);
   va_end(args);
 }
 
@@ -139,18 +97,19 @@
   }
 
   CHECK(c->IsErroneous()) << PrettyClass(c) << " " << c->GetStatus();
+  Thread* self = Thread::Current();
+  ThrowLocation throw_location = self->GetCurrentLocationForThrow();
   if (c->GetVerifyErrorClass() != NULL) {
     // TODO: change the verifier to store an _instance_, with a useful detail message?
     ClassHelper ve_ch(c->GetVerifyErrorClass());
-    std::string error_descriptor(ve_ch.GetDescriptor());
-    Thread::Current()->ThrowNewException(error_descriptor.c_str(), PrettyDescriptor(c).c_str());
+    self->ThrowNewException(throw_location, ve_ch.GetDescriptor(), PrettyDescriptor(c).c_str());
   } else {
-    ThrowNoClassDefFoundError("%s", PrettyDescriptor(c).c_str());
+    self->ThrowNewException(throw_location, "Ljava/lang/NoClassDefFoundError;",
+                            PrettyDescriptor(c).c_str());
   }
 }
 
-static void WrapExceptionInInitializer()
-    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+static void WrapExceptionInInitializer() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
   Thread* self = Thread::Current();
   JNIEnv* env = self->GetJniEnv();
 
@@ -163,7 +122,8 @@
 
   // We only wrap non-Error exceptions; an Error can just be used as-is.
   if (!is_error) {
-    self->ThrowNewWrappedException("Ljava/lang/ExceptionInInitializerError;", NULL);
+    ThrowLocation throw_location = self->GetCurrentLocationForThrow();
+    self->ThrowNewWrappedException(throw_location, "Ljava/lang/ExceptionInInitializerError;", NULL);
   }
 }
 
@@ -1244,8 +1204,7 @@
     ObjectLock lock(self, klass);
     // Check for circular dependencies between classes.
     if (!klass->IsResolved() && klass->GetClinitThreadId() == self->GetTid()) {
-      self->ThrowNewException("Ljava/lang/ClassCircularityError;",
-          PrettyDescriptor(klass).c_str());
+      ThrowClassCircularityError(klass);
       klass->SetStatus(mirror::Class::kStatusError);
       return NULL;
     }
@@ -1260,9 +1219,7 @@
   }
   // Return the loaded class.  No exceptions should be pending.
   CHECK(klass->IsResolved()) << PrettyClass(klass);
-  CHECK(!self->IsExceptionPending())
-      << PrettyClass(klass) << " " << PrettyTypeOf(self->GetException()) << "\n"
-      << self->GetException()->Dump();
+  self->AssertNoPendingException();
   return klass;
 }
 
@@ -1335,13 +1292,13 @@
                                                WellKnownClasses::java_lang_ClassLoader_loadClass,
                                                class_name_object.get()));
     }
-    if (soa.Env()->ExceptionCheck()) {
+    if (soa.Self()->IsExceptionPending()) {
       // If the ClassLoader threw, pass that exception up.
       return NULL;
     } else if (result.get() == NULL) {
       // broken loader - throw NPE to be compatible with Dalvik
-      ThrowNullPointerException("ClassLoader.loadClass returned null for %s",
-                                class_name_string.c_str());
+      ThrowNullPointerException(NULL, StringPrintf("ClassLoader.loadClass returned null for %s",
+                                                   class_name_string.c_str()).c_str());
       return NULL;
     } else {
       // success, return mirror::Class*
@@ -1560,7 +1517,7 @@
 
 // Special case to get oat code without overwriting a trampoline.
 const void* ClassLinker::GetOatCodeFor(const mirror::AbstractMethod* method) {
-  CHECK(Runtime::Current()->IsCompiler() || method->GetDeclaringClass()->IsInitializing());
+  CHECK(!method->IsAbstract()) << PrettyMethod(method);
   const void* result = GetOatMethodFor(method).GetCode();
   if (result == NULL) {
     // No code? You must mean to go into the interpreter.
@@ -1587,7 +1544,8 @@
   if (class_data == NULL) {
     return;  // no fields or methods - for example a marker interface
   }
-  if (!Runtime::Current()->IsStarted() || Runtime::Current()->UseCompileTimeClassPath()) {
+  Runtime* runtime = Runtime::Current();
+  if (!runtime->IsStarted() || runtime->UseCompileTimeClassPath()) {
     // OAT file unavailable
     return;
   }
@@ -1603,32 +1561,26 @@
   }
   size_t method_index = 0;
   // Link the code of methods skipped by LinkCode
-  const void* trampoline = Runtime::Current()->GetResolutionStubArray(Runtime::kStaticMethod)->GetData();
   for (size_t i = 0; it.HasNextDirectMethod(); i++, it.Next()) {
     mirror::AbstractMethod* method = klass->GetDirectMethod(i);
-    if (Runtime::Current()->IsMethodTracingActive()) {
-      Instrumentation* instrumentation = Runtime::Current()->GetInstrumentation();
-      if (instrumentation->GetSavedCodeFromMap(method) == trampoline) {
-        const void* code = oat_class->GetOatMethod(method_index).GetCode();
-        instrumentation->ResetSavedCode(method);
-        method->SetCode(code);
-        instrumentation->SaveAndUpdateCode(method);
-      }
-    } else if (method->GetCode() == trampoline) {
+    if (method->IsStatic()) {
       const void* code = oat_class->GetOatMethod(method_index).GetCode();
       if (code == NULL) {
         // No code? You must mean to go into the interpreter.
         code = GetInterpreterEntryPoint();
       }
-      method->SetCode(code);
+      runtime->GetInstrumentation()->UpdateMethodsCode(method, code);
     }
     method_index++;
   }
+  // Ignore virtual methods on the iterator.
 }
 
 static void LinkCode(SirtRef<mirror::AbstractMethod>& method, const OatFile::OatClass* oat_class,
                      uint32_t method_index)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+  // Method shouldn't have already been linked.
+  DCHECK(method->GetCode() == NULL);
   // Every kind of method should at least get an invoke stub from the oat_method.
   // non-abstract methods also get their code pointers.
   const OatFile::OatMethod oat_method = oat_class->GetOatMethod(method_index);
@@ -1641,23 +1593,22 @@
   }
 
   if (method->IsStatic() && !method->IsConstructor()) {
-    // For static methods excluding the class initializer, install the trampoline
+    // For static methods excluding the class initializer, install the trampoline.
     method->SetCode(runtime->GetResolutionStubArray(Runtime::kStaticMethod)->GetData());
   }
-  if (method->IsNative()) {
-    // unregistering restores the dlsym lookup stub
-    method->UnregisterNative(Thread::Current());
-  }
 
-  if (Runtime::Current()->IsMethodTracingActive()) {
-    Instrumentation* instrumentation = Runtime::Current()->GetInstrumentation();
-    instrumentation->SaveAndUpdateCode(method.get());
+  if (method->IsNative()) {
+    // Unregistering restores the dlsym lookup stub.
+    method->UnregisterNative(Thread::Current());
   }
 
   if (method->GetCode() == NULL) {
     // No code? You must mean to go into the interpreter.
     method->SetCode(GetInterpreterEntryPoint());
   }
+
+  // Allow instrumentation its chance to hijack code.
+  runtime->GetInstrumentation()->UpdateMethodsCode(method.get(), method->GetCode());
 }
 
 void ClassLinker::LoadClass(const DexFile& dex_file,
@@ -2229,7 +2180,6 @@
 
   // Verify super class.
   mirror::Class* super = klass->GetSuperClass();
-  std::string error_msg;
   if (super != NULL) {
     // Acquire lock to prevent races on verifying the super class.
     ObjectLock lock(self, super);
@@ -2238,18 +2188,17 @@
       Runtime::Current()->GetClassLinker()->VerifyClass(super);
     }
     if (!super->IsCompileTimeVerified()) {
-      error_msg = "Rejecting class ";
-      error_msg += PrettyDescriptor(klass);
-      error_msg += " that attempts to sub-class erroneous class ";
-      error_msg += PrettyDescriptor(super);
+      std::string error_msg(StringPrintf("Rejecting class %s that attempts to sub-class erroneous class %s",
+                                         PrettyDescriptor(klass).c_str(),
+                                         PrettyDescriptor(super).c_str()));
       LOG(ERROR) << error_msg  << " in " << klass->GetDexCache()->GetLocation()->ToModifiedUtf8();
-      SirtRef<mirror::Throwable> cause(self, self->GetException());
+      SirtRef<mirror::Throwable> cause(self, self->GetException(NULL));
       if (cause.get() != NULL) {
         self->ClearException();
       }
-      self->ThrowNewException("Ljava/lang/VerifyError;", error_msg.c_str());
+      ThrowVerifyError(klass, "%s", error_msg.c_str());
       if (cause.get() != NULL) {
-        self->GetException()->SetCause(cause.get());
+        self->GetException(NULL)->SetCause(cause.get());
       }
       klass->SetStatus(mirror::Class::kStatusError);
       return;
@@ -2264,13 +2213,12 @@
   if (oat_file_class_status == mirror::Class::kStatusError) {
     LOG(WARNING) << "Skipping runtime verification of erroneous class " << PrettyDescriptor(klass)
                  << " in " << klass->GetDexCache()->GetLocation()->ToModifiedUtf8();
-    error_msg = "Rejecting class ";
-    error_msg += PrettyDescriptor(klass);
-    error_msg += " because it failed compile-time verification";
-    Thread::Current()->ThrowNewException("Ljava/lang/VerifyError;", error_msg.c_str());
+    ThrowVerifyError(klass, "Rejecting class %s because it failed compile-time verification",
+                     PrettyDescriptor(klass).c_str());
     klass->SetStatus(mirror::Class::kStatusError);
     return;
   }
+  std::string error_msg;
   if (!preverified) {
     verifier_failure = verifier::MethodVerifier::VerifyClass(klass, error_msg);
   }
@@ -2301,7 +2249,7 @@
         << " in " << klass->GetDexCache()->GetLocation()->ToModifiedUtf8()
         << " because: " << error_msg;
     self->AssertNoPendingException();
-    self->ThrowNewException("Ljava/lang/VerifyError;", error_msg.c_str());
+    ThrowVerifyError(klass, "%s", error_msg.c_str());
     klass->SetStatus(mirror::Class::kStatusError);
   }
 }
@@ -2463,7 +2411,7 @@
 
   klass->SetSuperClass(proxy_class);  // The super class is java.lang.reflect.Proxy
   klass->SetStatus(mirror::Class::kStatusLoaded);  // Class is now effectively in the loaded state
-  DCHECK(!Thread::Current()->IsExceptionPending());
+  self->AssertNoPendingException();
 
   // Link the fields and virtual methods, creating vtable and iftables
   if (!LinkClass(klass, interfaces)) {
@@ -2798,7 +2746,7 @@
       const mirror::AbstractMethod* method = klass->GetVTable()->Get(i);
       if (method != super->GetVTable()->Get(i) &&
           !IsSameMethodSignatureInDifferentClassContexts(method, super, klass)) {
-        ThrowLinkageError("Class %s method %s resolves differently in superclass %s",
+        ThrowLinkageError(klass, "Class %s method %s resolves differently in superclass %s",
                           PrettyDescriptor(klass).c_str(), PrettyMethod(method).c_str(),
                           PrettyDescriptor(super).c_str());
         return false;
@@ -2813,7 +2761,7 @@
         const mirror::AbstractMethod* method = iftable->GetMethodArray(i)->Get(j);
         if (!IsSameMethodSignatureInDifferentClassContexts(method, interface,
                                                            method->GetDeclaringClass())) {
-          ThrowLinkageError("Class %s method %s resolves differently in interface %s",
+          ThrowLinkageError(klass, "Class %s method %s resolves differently in interface %s",
                             PrettyDescriptor(method->GetDeclaringClass()).c_str(),
                             PrettyMethod(method).c_str(),
                             PrettyDescriptor(interface).c_str());
@@ -2996,10 +2944,9 @@
     }
     // Verify
     if (!klass->CanAccess(super_class)) {
-      Thread::Current()->ThrowNewExceptionF("Ljava/lang/IllegalAccessError;",
-          "Class %s extended by class %s is inaccessible",
-          PrettyDescriptor(super_class).c_str(),
-          PrettyDescriptor(klass.get()).c_str());
+      ThrowIllegalAccessError(klass.get(), "Class %s extended by class %s is inaccessible",
+                              PrettyDescriptor(super_class).c_str(),
+                              PrettyDescriptor(klass.get()).c_str());
       return false;
     }
     klass->SetSuperClass(super_class);
@@ -3016,10 +2963,9 @@
       // Verify
       if (!klass->CanAccess(interface)) {
         // TODO: the RI seemed to ignore this in my testing.
-        Thread::Current()->ThrowNewExceptionF("Ljava/lang/IllegalAccessError;",
-            "Interface %s implemented by class %s is inaccessible",
-            PrettyDescriptor(interface).c_str(),
-            PrettyDescriptor(klass.get()).c_str());
+        ThrowIllegalAccessError(klass.get(), "Interface %s implemented by class %s is inaccessible",
+                                PrettyDescriptor(interface).c_str(),
+                                PrettyDescriptor(klass.get()).c_str());
         return false;
       }
     }
@@ -3034,31 +2980,28 @@
   mirror::Class* super = klass->GetSuperClass();
   if (klass.get() == GetClassRoot(kJavaLangObject)) {
     if (super != NULL) {
-      Thread::Current()->ThrowNewExceptionF("Ljava/lang/ClassFormatError;",
-          "java.lang.Object must not have a superclass");
+      ThrowClassFormatError(klass.get(), "java.lang.Object must not have a superclass");
       return false;
     }
     return true;
   }
   if (super == NULL) {
-    ThrowLinkageError("No superclass defined for class %s", PrettyDescriptor(klass.get()).c_str());
+    ThrowLinkageError(klass.get(), "No superclass defined for class %s",
+                      PrettyDescriptor(klass.get()).c_str());
     return false;
   }
   // Verify
   if (super->IsFinal() || super->IsInterface()) {
-    Thread* self = Thread::Current();
-    self->ThrowNewExceptionF("Ljava/lang/IncompatibleClassChangeError;",
-        "Superclass %s of %s is %s",
-        PrettyDescriptor(super).c_str(),
-        PrettyDescriptor(klass.get()).c_str(),
-        super->IsFinal() ? "declared final" : "an interface");
+    ThrowIncompatibleClassChangeError(klass.get(), "Superclass %s of %s is %s",
+                                      PrettyDescriptor(super).c_str(),
+                                      PrettyDescriptor(klass.get()).c_str(),
+                                      super->IsFinal() ? "declared final" : "an interface");
     return false;
   }
   if (!klass->CanAccess(super)) {
-    Thread::Current()->ThrowNewExceptionF("Ljava/lang/IllegalAccessError;",
-        "Superclass %s is inaccessible by %s",
-        PrettyDescriptor(super).c_str(),
-        PrettyDescriptor(klass.get()).c_str());
+    ThrowIllegalAccessError(klass.get(), "Superclass %s is inaccessible to class %s",
+                            PrettyDescriptor(super).c_str(),
+                            PrettyDescriptor(klass.get()).c_str());
     return false;
   }
 
@@ -3074,8 +3017,9 @@
   }
   // Disallow custom direct subclasses of java.lang.ref.Reference.
   if (init_done_ && super == GetClassRoot(kJavaLangRefReference)) {
-    ThrowLinkageError("Class %s attempts to subclass java.lang.ref.Reference, which is not allowed",
-        PrettyDescriptor(klass.get()).c_str());
+    ThrowLinkageError(klass.get(),
+                      "Class %s attempts to subclass java.lang.ref.Reference, which is not allowed",
+                      PrettyDescriptor(klass.get()).c_str());
     return false;
   }
 
@@ -3096,7 +3040,7 @@
     // No vtable.
     size_t count = klass->NumVirtualMethods();
     if (!IsUint(16, count)) {
-      ThrowClassFormatError("Too many methods on interface: %zd", count);
+      ThrowClassFormatError(klass.get(), "Too many methods on interface: %zd", count);
       return false;
     }
     for (size_t i = 0; i < count; ++i) {
@@ -3133,7 +3077,7 @@
         if (local_mh.HasSameNameAndSignature(&super_mh)) {
           if (klass->CanAccessMember(super_method->GetDeclaringClass(), super_method->GetAccessFlags())) {
             if (super_method->IsFinal()) {
-              ThrowLinkageError("Method %s overrides final method in class %s",
+              ThrowLinkageError(klass.get(), "Method %s overrides final method in class %s",
                                 PrettyMethod(local_method).c_str(),
                                 super_mh.GetDeclaringClassDescriptor());
               return false;
@@ -3156,7 +3100,7 @@
       }
     }
     if (!IsUint(16, actual_count)) {
-      ThrowClassFormatError("Too many methods defined on class: %zd", actual_count);
+      ThrowClassFormatError(klass.get(), "Too many methods defined on class: %zd", actual_count);
       return false;
     }
     // Shrink vtable if possible
@@ -3169,7 +3113,7 @@
     CHECK(klass.get() == GetClassRoot(kJavaLangObject));
     uint32_t num_virtual_methods = klass->NumVirtualMethods();
     if (!IsUint(16, num_virtual_methods)) {
-      ThrowClassFormatError("Too many methods: %d", num_virtual_methods);
+      ThrowClassFormatError(klass.get(), "Too many methods: %d", num_virtual_methods);
       return false;
     }
     SirtRef<mirror::ObjectArray<mirror::AbstractMethod> >
@@ -3238,10 +3182,9 @@
     DCHECK(interface != NULL);
     if (!interface->IsInterface()) {
       ClassHelper ih(interface);
-      self->ThrowNewExceptionF("Ljava/lang/IncompatibleClassChangeError;",
-          "Class %s implements non-interface class %s",
-          PrettyDescriptor(klass.get()).c_str(),
-          PrettyDescriptor(ih.GetDescriptor()).c_str());
+      ThrowIncompatibleClassChangeError(klass.get(), "Class %s implements non-interface class %s",
+                                        PrettyDescriptor(klass.get()).c_str(),
+                                        PrettyDescriptor(ih.GetDescriptor()).c_str());
       return false;
     }
     // Check if interface is already in iftable
@@ -3297,7 +3240,7 @@
           AllocMethodArray(self, num_methods);
       iftable->SetMethodArray(i, method_array);
       mirror::ObjectArray<mirror::AbstractMethod>* vtable = klass->GetVTableDuringLinking();
-      for (size_t j = 0; j < interface->NumVirtualMethods(); ++j) {
+      for (size_t j = 0; j < num_methods; ++j) {
         mirror::AbstractMethod* interface_method = interface->GetVirtualMethod(j);
         interface_mh.ChangeMethod(interface_method);
         int32_t k;
@@ -3314,9 +3257,10 @@
           vtable_mh.ChangeMethod(vtable_method);
           if (interface_mh.HasSameNameAndSignature(&vtable_mh)) {
             if (!vtable_method->IsAbstract() && !vtable_method->IsPublic()) {
-              self->ThrowNewExceptionF("Ljava/lang/IllegalAccessError;",
-                                       "Implementation not public: %s",
-                                       PrettyMethod(vtable_method).c_str());
+              ThrowIllegalAccessError(klass.get(),
+                                      "Method '%s' implementing interface method '%s' is not public",
+                                      PrettyMethod(vtable_method).c_str(),
+                                      PrettyMethod(interface_method).c_str());
               return false;
             }
             method_array->Set(j, vtable_method);
@@ -3657,12 +3601,15 @@
       //       same name to be loaded simultaneously by different loaders
       dex_cache->SetResolvedType(type_idx, resolved);
     } else {
-      CHECK(Thread::Current()->IsExceptionPending())
+      Thread* self = Thread::Current();
+      CHECK(self->IsExceptionPending())
           << "Expected pending exception for failed resolution of: " << descriptor;
-      // Convert a ClassNotFoundException to a NoClassDefFoundError
-      if (Thread::Current()->GetException()->InstanceOf(GetClassRoot(kJavaLangClassNotFoundException))) {
+      // Convert a ClassNotFoundException to a NoClassDefFoundError.
+      SirtRef<mirror::Throwable> cause(self, self->GetException(NULL));
+      if (cause->InstanceOf(GetClassRoot(kJavaLangClassNotFoundException))) {
         Thread::Current()->ClearException();
         ThrowNoClassDefFoundError("Failed resolution of: %s", descriptor);
+        self->GetException(NULL)->SetCause(cause.get());
       }
     }
   }
@@ -3779,7 +3726,7 @@
           if (resolved != NULL) {
             ThrowIncompatibleClassChangeError(type, kInterface, resolved, referrer);
           } else {
-            ThrowNoSuchMethodError(type, klass, name, signature, referrer);
+            ThrowNoSuchMethodError(type, klass, name, signature);
           }
         }
         break;
@@ -3791,12 +3738,12 @@
           if (resolved != NULL) {
             ThrowIncompatibleClassChangeError(type, kVirtual, resolved, referrer);
           } else {
-            ThrowNoSuchMethodError(type, klass, name, signature, referrer);
+            ThrowNoSuchMethodError(type, klass, name, signature);
           }
         }
         break;
       case kSuper:
-        ThrowNoSuchMethodError(type, klass, name, signature, referrer);
+        ThrowNoSuchMethodError(type, klass, name, signature);
         break;
       case kVirtual:
         if (resolved != NULL) {
@@ -3806,7 +3753,7 @@
           if (resolved != NULL) {
             ThrowIncompatibleClassChangeError(type, kInterface, resolved, referrer);
           } else {
-            ThrowNoSuchMethodError(type, klass, name, signature, referrer);
+            ThrowNoSuchMethodError(type, klass, name, signature);
           }
         }
         break;
diff --git a/src/class_linker_test.cc b/src/class_linker_test.cc
index 6b8083f..c47ce4a 100644
--- a/src/class_linker_test.cc
+++ b/src/class_linker_test.cc
@@ -46,7 +46,7 @@
     EXPECT_TRUE(class_linker_->FindSystemClass(descriptor.c_str()) == NULL);
     Thread* self = Thread::Current();
     EXPECT_TRUE(self->IsExceptionPending());
-    Object* exception = self->GetException();
+    Object* exception = self->GetException(NULL);
     self->ClearException();
     Class* exception_class = class_linker_->FindSystemClass("Ljava/lang/NoClassDefFoundError;");
     EXPECT_TRUE(exception->InstanceOf(exception_class));
diff --git a/src/common_throws.cc b/src/common_throws.cc
index 8673d11..0bb9da2 100644
--- a/src/common_throws.cc
+++ b/src/common_throws.cc
@@ -32,18 +32,7 @@
 
 namespace art {
 
-static void AddReferrerLocation(std::ostream& os, const mirror::AbstractMethod* referrer)
-    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
-  if (referrer != NULL) {
-    ClassHelper kh(referrer->GetDeclaringClass());
-    std::string location(kh.GetLocation());
-    if (!location.empty()) {
-      os << " (accessed from " << location << ")";
-    }
-  }
-}
-
-static void AddReferrerLocationFromClass(std::ostream& os, mirror::Class* referrer)
+static void AddReferrerLocation(std::ostream& os, const mirror::Class* referrer)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
   if (referrer != NULL) {
     ClassHelper kh(referrer);
@@ -55,112 +44,86 @@
   }
 }
 
-// NullPointerException
-
-void ThrowNullPointerExceptionForFieldAccess(mirror::Field* field, bool is_read) {
+static void ThrowException(const ThrowLocation* throw_location, const char* exception_descriptor,
+                           const mirror::Class* referrer, const char* fmt, va_list* args = NULL)
+    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
   std::ostringstream msg;
-  msg << "Attempt to " << (is_read ? "read from" : "write to")
-      << " field '" << PrettyField(field, true) << "' on a null object reference";
-  Thread::Current()->ThrowNewException("Ljava/lang/NullPointerException;", msg.str().c_str());
-}
-
-void ThrowNullPointerExceptionForMethodAccess(mirror::AbstractMethod* caller, uint32_t method_idx,
-                                              InvokeType type) {
-  mirror::DexCache* dex_cache = caller->GetDeclaringClass()->GetDexCache();
-  const DexFile& dex_file = *dex_cache->GetDexFile();
-  std::ostringstream msg;
-  msg << "Attempt to invoke " << type << " method '"
-      << PrettyMethod(method_idx, dex_file, true) << "' on a null object reference";
-  Thread::Current()->ThrowNewException("Ljava/lang/NullPointerException;", msg.str().c_str());
-}
-
-void ThrowNullPointerExceptionFromDexPC(mirror::AbstractMethod* throw_method, uint32_t dex_pc) {
-  const DexFile::CodeItem* code = MethodHelper(throw_method).GetCodeItem();
-  CHECK_LT(dex_pc, code->insns_size_in_code_units_);
-  const Instruction* instr = Instruction::At(&code->insns_[dex_pc]);
-  DecodedInstruction dec_insn(instr);
-  switch (instr->Opcode()) {
-    case Instruction::INVOKE_DIRECT:
-    case Instruction::INVOKE_DIRECT_RANGE:
-      ThrowNullPointerExceptionForMethodAccess(throw_method, dec_insn.vB, kDirect);
-      break;
-    case Instruction::INVOKE_VIRTUAL:
-    case Instruction::INVOKE_VIRTUAL_RANGE:
-      ThrowNullPointerExceptionForMethodAccess(throw_method, dec_insn.vB, kVirtual);
-      break;
-    case Instruction::INVOKE_INTERFACE:
-    case Instruction::INVOKE_INTERFACE_RANGE:
-      ThrowNullPointerExceptionForMethodAccess(throw_method, dec_insn.vB, kInterface);
-      break;
-    case Instruction::IGET:
-    case Instruction::IGET_WIDE:
-    case Instruction::IGET_OBJECT:
-    case Instruction::IGET_BOOLEAN:
-    case Instruction::IGET_BYTE:
-    case Instruction::IGET_CHAR:
-    case Instruction::IGET_SHORT: {
-      mirror::Field* field =
-          Runtime::Current()->GetClassLinker()->ResolveField(dec_insn.vC, throw_method, false);
-      ThrowNullPointerExceptionForFieldAccess(field, true /* read */);
-      break;
-    }
-    case Instruction::IPUT:
-    case Instruction::IPUT_WIDE:
-    case Instruction::IPUT_OBJECT:
-    case Instruction::IPUT_BOOLEAN:
-    case Instruction::IPUT_BYTE:
-    case Instruction::IPUT_CHAR:
-    case Instruction::IPUT_SHORT: {
-      mirror::Field* field =
-          Runtime::Current()->GetClassLinker()->ResolveField(dec_insn.vC, throw_method, false);
-      ThrowNullPointerExceptionForFieldAccess(field, false /* write */);
-      break;
-    }
-    case Instruction::AGET:
-    case Instruction::AGET_WIDE:
-    case Instruction::AGET_OBJECT:
-    case Instruction::AGET_BOOLEAN:
-    case Instruction::AGET_BYTE:
-    case Instruction::AGET_CHAR:
-    case Instruction::AGET_SHORT:
-      Thread::Current()->ThrowNewException("Ljava/lang/NullPointerException;",
-                                           "Attempt to read from null array");
-      break;
-    case Instruction::APUT:
-    case Instruction::APUT_WIDE:
-    case Instruction::APUT_OBJECT:
-    case Instruction::APUT_BOOLEAN:
-    case Instruction::APUT_BYTE:
-    case Instruction::APUT_CHAR:
-    case Instruction::APUT_SHORT:
-      Thread::Current()->ThrowNewException("Ljava/lang/NullPointerException;",
-                                           "Attempt to write to null array");
-      break;
-    case Instruction::ARRAY_LENGTH:
-      Thread::Current()->ThrowNewException("Ljava/lang/NullPointerException;",
-                                           "Attempt to get length of null array");
-      break;
-    default: {
-      // TODO: We should have covered all the cases where we expect a NPE above, this
-      //       message/logging is so we can improve any cases we've missed in the future.
-      const DexFile& dex_file = *throw_method->GetDeclaringClass()->GetDexCache()->GetDexFile();
-      std::string message("Null pointer exception during instruction '");
-      message += instr->DumpString(&dex_file);
-      message += "'";
-      Thread::Current()->ThrowNewException("Ljava/lang/NullPointerException;", message.c_str());
-      break;
-    }
+  if (args != NULL) {
+    std::string vmsg;
+    StringAppendV(&vmsg, fmt, *args);
+    msg << vmsg;
+  } else {
+    msg << fmt;
+  }
+  AddReferrerLocation(msg, referrer);
+  Thread* self = Thread::Current();
+  if (throw_location == NULL) {
+    ThrowLocation computed_throw_location = self->GetCurrentLocationForThrow();
+    self->ThrowNewException(computed_throw_location, exception_descriptor, msg.str().c_str());
+  } else {
+    self->ThrowNewException(*throw_location, exception_descriptor, msg.str().c_str());
   }
 }
 
+// ArithmeticException
+
+void ThrowArithmeticExceptionDivideByZero(Thread* self) {
+  ThrowException(NULL, "Ljava/lang/ArithmeticException;", NULL, "divide by zero");
+}
+
+// ArrayIndexOutOfBoundsException
+
+void ThrowArrayIndexOutOfBoundsException(int index, int length) {
+  ThrowException(NULL, "Ljava/lang/ArrayIndexOutOfBoundsException;", NULL,
+                 StringPrintf("length=%d; index=%d", length, index).c_str());
+}
+
+// ArrayStoreException
+
+void ThrowArrayStoreException(const mirror::Class* element_class,
+                              const mirror::Class* array_class) {
+  ThrowException(NULL, "Ljava/lang/ArrayStoreException;", NULL,
+                 StringPrintf("%s cannot be stored in an array of type %s",
+                              PrettyDescriptor(element_class).c_str(),
+                              PrettyDescriptor(array_class).c_str()).c_str());
+}
+
+// ClassCastException
+
+void ThrowClassCastException(const mirror::Class* dest_type, const mirror::Class* src_type) {
+  ThrowException(NULL, "Ljava/lang/ClassCastException;", NULL,
+                 StringPrintf("%s cannot be cast to %s",
+                              PrettyDescriptor(src_type).c_str(),
+                              PrettyDescriptor(dest_type).c_str()).c_str());
+}
+
+void ThrowClassCastException(const ThrowLocation* throw_location, const char* msg) {
+  ThrowException(throw_location, "Ljava/lang/ClassCastException;", NULL, msg);
+}
+
+// ClassCircularityError
+
+void ThrowClassCircularityError(mirror::Class* c) {
+  std::ostringstream msg;
+  msg << PrettyDescriptor(c);
+  ThrowException(NULL, "Ljava/lang/ClassCircularityError;", c, msg.str().c_str());
+}
+
+// ClassFormatError
+
+void ThrowClassFormatError(const mirror::Class* referrer, const char* fmt, ...) {
+  va_list args;
+  va_start(args, fmt);
+  ThrowException(NULL, "Ljava/lang/ClassFormatError;", referrer, fmt, &args);
+  va_end(args);}
+
 // IllegalAccessError
 
 void ThrowIllegalAccessErrorClass(mirror::Class* referrer, mirror::Class* accessed) {
   std::ostringstream msg;
   msg << "Illegal class access: '" << PrettyDescriptor(referrer) << "' attempting to access '"
       << PrettyDescriptor(accessed) << "'";
-  AddReferrerLocationFromClass(msg, referrer);
-  Thread::Current()->ThrowNewException("Ljava/lang/IllegalAccessError;", msg.str().c_str());
+  ThrowException(NULL, "Ljava/lang/IllegalAccessError;", referrer, msg.str().c_str());
 }
 
 void ThrowIllegalAccessErrorClassForMethodDispatch(mirror::Class* referrer, mirror::Class* accessed,
@@ -171,24 +134,21 @@
   msg << "Illegal class access ('" << PrettyDescriptor(referrer) << "' attempting to access '"
       << PrettyDescriptor(accessed) << "') in attempt to invoke " << type
       << " method " << PrettyMethod(called).c_str();
-  AddReferrerLocation(msg, caller);
-  Thread::Current()->ThrowNewException("Ljava/lang/IllegalAccessError;", msg.str().c_str());
+  ThrowException(NULL, "Ljava/lang/IllegalAccessError;", referrer, msg.str().c_str());
 }
 
 void ThrowIllegalAccessErrorMethod(mirror::Class* referrer, mirror::AbstractMethod* accessed) {
   std::ostringstream msg;
   msg << "Method '" << PrettyMethod(accessed) << "' is inaccessible to class '"
       << PrettyDescriptor(referrer) << "'";
-  AddReferrerLocationFromClass(msg, referrer);
-  Thread::Current()->ThrowNewException("Ljava/lang/IllegalAccessError;", msg.str().c_str());
+  ThrowException(NULL, "Ljava/lang/IllegalAccessError;", referrer, msg.str().c_str());
 }
 
 void ThrowIllegalAccessErrorField(mirror::Class* referrer, mirror::Field* accessed) {
   std::ostringstream msg;
   msg << "Field '" << PrettyField(accessed, false) << "' is inaccessible to class '"
       << PrettyDescriptor(referrer) << "'";
-  AddReferrerLocationFromClass(msg, referrer);
-  Thread::Current()->ThrowNewException("Ljava/lang/IllegalAccessError;", msg.str().c_str());
+  ThrowException(NULL, "Ljava/lang/IllegalAccessError;", referrer, msg.str().c_str());
 }
 
 void ThrowIllegalAccessErrorFinalField(const mirror::AbstractMethod* referrer,
@@ -196,10 +156,24 @@
   std::ostringstream msg;
   msg << "Final field '" << PrettyField(accessed, false) << "' cannot be written to by method '"
       << PrettyMethod(referrer) << "'";
-  AddReferrerLocation(msg, referrer);
-  Thread::Current()->ThrowNewException("Ljava/lang/IllegalAccessError;", msg.str().c_str());
+  ThrowException(NULL, "Ljava/lang/IllegalAccessError;", referrer != NULL ? referrer->GetClass() : NULL,
+                 msg.str().c_str());
 }
 
+void ThrowIllegalAccessError(mirror::Class* referrer, const char* fmt, ...){
+  va_list args;
+  va_start(args, fmt);
+  ThrowException(NULL, "Ljava/lang/IllegalAccessError;", referrer, fmt, &args);
+  va_end(args);
+}
+
+// IllegalArgumentException
+
+void ThrowIllegalArgumentException(const ThrowLocation* throw_location, const char* msg) {
+  ThrowException(throw_location, "Ljava/lang/IllegalArgumentException;", NULL, msg);
+}
+
+
 // IncompatibleClassChangeError
 
 void ThrowIncompatibleClassChangeError(InvokeType expected_type, InvokeType found_type,
@@ -208,9 +182,9 @@
   std::ostringstream msg;
   msg << "The method '" << PrettyMethod(method) << "' was expected to be of type "
       << expected_type << " but instead was found to be of type " << found_type;
-  AddReferrerLocation(msg, referrer);
-  Thread::Current()->ThrowNewException("Ljava/lang/IncompatibleClassChangeError;",
-                                       msg.str().c_str());
+  ThrowException(NULL, "Ljava/lang/IncompatibleClassChangeError;",
+                 referrer != NULL ? referrer->GetClass() : NULL,
+                 msg.str().c_str());
 }
 
 void ThrowIncompatibleClassChangeErrorClassForInterfaceDispatch(const mirror::AbstractMethod* interface_method,
@@ -224,9 +198,9 @@
       << "' does not implement interface '"
       << PrettyDescriptor(interface_method->GetDeclaringClass())
       << "' in call to '" << PrettyMethod(interface_method) << "'";
-  AddReferrerLocation(msg, referrer);
-  Thread::Current()->ThrowNewException("Ljava/lang/IncompatibleClassChangeError;",
-                                       msg.str().c_str());
+  ThrowException(NULL, "Ljava/lang/IncompatibleClassChangeError;",
+                 referrer != NULL ? referrer->GetClass() : NULL,
+                 msg.str().c_str());
 }
 
 void ThrowIncompatibleClassChangeErrorField(const mirror::Field* resolved_field, bool is_static,
@@ -235,30 +209,192 @@
   msg << "Expected '" << PrettyField(resolved_field) << "' to be a "
       << (is_static ? "static" : "instance") << " field" << " rather than a "
       << (is_static ? "instance" : "static") << " field";
-  AddReferrerLocation(msg, referrer);
-  Thread::Current()->ThrowNewException("Ljava/lang/IncompatibleClassChangeError;",
-                                       msg.str().c_str());
+  ThrowException(NULL, "Ljava/lang/IncompatibleClassChangeError;", referrer->GetClass(),
+                 msg.str().c_str());
+}
+
+void ThrowIncompatibleClassChangeError(const mirror::Class* referrer, const char* fmt, ...){
+  va_list args;
+  va_start(args, fmt);
+  ThrowException(NULL, "Ljava/lang/IncompatibleClassChangeError;", referrer, fmt, &args);
+  va_end(args);
+}
+
+// LinkageError
+
+void ThrowLinkageError(const mirror::Class* referrer, const char* fmt, ...) {
+  va_list args;
+  va_start(args, fmt);
+  ThrowException(NULL, "Ljava/lang/LinkageError;", referrer, fmt, &args);
+  va_end(args);
+}
+
+// NegativeArraySizeException
+
+void ThrowNegativeArraySizeException(int size) {
+  ThrowException(NULL, "Ljava/lang/NegativeArraySizeException;", NULL, StringPrintf("%d", size).c_str());
+}
+
+void ThrowNegativeArraySizeException(const char* msg) {
+  ThrowException(NULL, "Ljava/lang/NegativeArraySizeException;", NULL, msg);
+}
+
+// NoSuchFieldError
+
+void ThrowNoSuchFieldError(const StringPiece& scope, mirror::Class* c,
+                           const StringPiece& type, const StringPiece& name)
+    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+  ClassHelper kh(c);
+  std::ostringstream msg;
+  msg << "No " << scope << "field " << name << " of type " << type
+      << " in class " << kh.GetDescriptor() << " or its superclasses";
+  ThrowException(NULL, "Ljava/lang/NoSuchFieldError;", c, msg.str().c_str());
 }
 
 // NoSuchMethodError
 
 void ThrowNoSuchMethodError(InvokeType type, mirror::Class* c, const StringPiece& name,
-                            const StringPiece& signature, const mirror::AbstractMethod* referrer) {
+                            const StringPiece& signature) {
   std::ostringstream msg;
   ClassHelper kh(c);
   msg << "No " << type << " method " << name << signature
       << " in class " << kh.GetDescriptor() << " or its super classes";
-  AddReferrerLocation(msg, referrer);
-  Thread::Current()->ThrowNewException("Ljava/lang/NoSuchMethodError;", msg.str().c_str());
+  ThrowException(NULL, "Ljava/lang/NoSuchMethodError;", c, msg.str().c_str());
 }
 
-void ThrowNoSuchMethodError(uint32_t method_idx, const mirror::AbstractMethod* referrer) {
-  mirror::DexCache* dex_cache = referrer->GetDeclaringClass()->GetDexCache();
+void ThrowNoSuchMethodError(uint32_t method_idx) {
+  Thread* self = Thread::Current();
+  ThrowLocation throw_location = self->GetCurrentLocationForThrow();
+  mirror::DexCache* dex_cache = throw_location.GetMethod()->GetDeclaringClass()->GetDexCache();
   const DexFile& dex_file = *dex_cache->GetDexFile();
   std::ostringstream msg;
   msg << "No method '" << PrettyMethod(method_idx, dex_file, true) << "'";
-  AddReferrerLocation(msg, referrer);
-  Thread::Current()->ThrowNewException("Ljava/lang/NoSuchMethodError;", msg.str().c_str());
+  ThrowException(&throw_location, "Ljava/lang/NoSuchMethodError;",
+                 throw_location.GetMethod()->GetDeclaringClass(), msg.str().c_str());
+}
+
+// NullPointerException
+
+void ThrowNullPointerExceptionForFieldAccess(const ThrowLocation& throw_location,
+                                             mirror::Field* field, bool is_read) {
+  std::ostringstream msg;
+  msg << "Attempt to " << (is_read ? "read from" : "write to")
+      << " field '" << PrettyField(field, true) << "' on a null object reference";
+  ThrowException(&throw_location, "Ljava/lang/NullPointerException;", NULL, msg.str().c_str());
+}
+
+void ThrowNullPointerExceptionForMethodAccess(const ThrowLocation& throw_location, uint32_t method_idx,
+                                              InvokeType type) {
+  mirror::DexCache* dex_cache = throw_location.GetMethod()->GetDeclaringClass()->GetDexCache();
+  const DexFile& dex_file = *dex_cache->GetDexFile();
+  std::ostringstream msg;
+  msg << "Attempt to invoke " << type << " method '"
+      << PrettyMethod(method_idx, dex_file, true) << "' on a null object reference";
+  ThrowException(&throw_location, "Ljava/lang/NullPointerException;", NULL, msg.str().c_str());
+}
+
+void ThrowNullPointerExceptionFromDexPC(const ThrowLocation& throw_location) {
+  const DexFile::CodeItem* code = MethodHelper(throw_location.GetMethod()).GetCodeItem();
+  uint32_t throw_dex_pc = throw_location.GetDexPc();
+  CHECK_LT(throw_dex_pc, code->insns_size_in_code_units_);
+  const Instruction* instr = Instruction::At(&code->insns_[throw_dex_pc]);
+  DecodedInstruction dec_insn(instr);
+  switch (instr->Opcode()) {
+    case Instruction::INVOKE_DIRECT:
+    case Instruction::INVOKE_DIRECT_RANGE:
+      ThrowNullPointerExceptionForMethodAccess(throw_location, dec_insn.vB, kDirect);
+      break;
+    case Instruction::INVOKE_VIRTUAL:
+    case Instruction::INVOKE_VIRTUAL_RANGE:
+      ThrowNullPointerExceptionForMethodAccess(throw_location, dec_insn.vB, kVirtual);
+      break;
+    case Instruction::INVOKE_INTERFACE:
+    case Instruction::INVOKE_INTERFACE_RANGE:
+      ThrowNullPointerExceptionForMethodAccess(throw_location, dec_insn.vB, kInterface);
+      break;
+    case Instruction::IGET:
+    case Instruction::IGET_WIDE:
+    case Instruction::IGET_OBJECT:
+    case Instruction::IGET_BOOLEAN:
+    case Instruction::IGET_BYTE:
+    case Instruction::IGET_CHAR:
+    case Instruction::IGET_SHORT: {
+      mirror::Field* field =
+          Runtime::Current()->GetClassLinker()->ResolveField(dec_insn.vC,
+                                                             throw_location.GetMethod(), false);
+      ThrowNullPointerExceptionForFieldAccess(throw_location, field, true /* read */);
+      break;
+    }
+    case Instruction::IPUT:
+    case Instruction::IPUT_WIDE:
+    case Instruction::IPUT_OBJECT:
+    case Instruction::IPUT_BOOLEAN:
+    case Instruction::IPUT_BYTE:
+    case Instruction::IPUT_CHAR:
+    case Instruction::IPUT_SHORT: {
+      mirror::Field* field =
+          Runtime::Current()->GetClassLinker()->ResolveField(dec_insn.vC,
+                                                             throw_location.GetMethod(), false);
+      ThrowNullPointerExceptionForFieldAccess(throw_location, field, false /* write */);
+      break;
+    }
+    case Instruction::AGET:
+    case Instruction::AGET_WIDE:
+    case Instruction::AGET_OBJECT:
+    case Instruction::AGET_BOOLEAN:
+    case Instruction::AGET_BYTE:
+    case Instruction::AGET_CHAR:
+    case Instruction::AGET_SHORT:
+      ThrowException(&throw_location, "Ljava/lang/NullPointerException;", NULL,
+                     "Attempt to read from null array");
+      break;
+    case Instruction::APUT:
+    case Instruction::APUT_WIDE:
+    case Instruction::APUT_OBJECT:
+    case Instruction::APUT_BOOLEAN:
+    case Instruction::APUT_BYTE:
+    case Instruction::APUT_CHAR:
+    case Instruction::APUT_SHORT:
+      ThrowException(&throw_location, "Ljava/lang/NullPointerException;", NULL,
+                     "Attempt to write to null array");
+      break;
+    case Instruction::ARRAY_LENGTH:
+      ThrowException(&throw_location, "Ljava/lang/NullPointerException;", NULL,
+                     "Attempt to get length of null array");
+      break;
+    default: {
+      // TODO: We should have covered all the cases where we expect a NPE above, this
+      //       message/logging is so we can improve any cases we've missed in the future.
+      const DexFile& dex_file =
+          *throw_location.GetMethod()->GetDeclaringClass()->GetDexCache()->GetDexFile();
+      ThrowException(&throw_location, "Ljava/lang/NullPointerException;", NULL,
+                     StringPrintf("Null pointer exception during instruction '%s'",
+                                  instr->DumpString(&dex_file).c_str()).c_str());
+      break;
+    }
+  }
+}
+
+void ThrowNullPointerException(const ThrowLocation* throw_location, const char* msg) {
+  ThrowException(throw_location, "Ljava/lang/NullPointerException;", NULL, msg);
+}
+
+// RuntimeException
+
+void ThrowRuntimeException(const char* fmt, ...) {
+  va_list args;
+  va_start(args, fmt);
+  ThrowException(NULL, "Ljava/lang/RuntimeException;", NULL, fmt, &args);
+  va_end(args);
+}
+
+// VerifyError
+
+void ThrowVerifyError(const mirror::Class* referrer, const char* fmt, ...) {
+  va_list args;
+  va_start(args, fmt);
+  ThrowException(NULL, "Ljava/lang/VerifyError;", referrer, fmt, &args);
+  va_end(args);
 }
 
 }  // namespace art
diff --git a/src/common_throws.h b/src/common_throws.h
index 9e28bd7..5555435 100644
--- a/src/common_throws.h
+++ b/src/common_throws.h
@@ -28,17 +28,39 @@
 class Object;
 }  // namespace mirror
 class StringPiece;
+class ThrowLocation;
 
-// NullPointerException
+// ArithmeticException
 
-void ThrowNullPointerExceptionForFieldAccess(mirror::Field* field, bool is_read)
+void ThrowArithmeticExceptionDivideByZero(Thread* self) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+// ArrayIndexOutOfBoundsException
+
+void ThrowArrayIndexOutOfBoundsException(int index, int length)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
-void ThrowNullPointerExceptionForMethodAccess(mirror::AbstractMethod* caller, uint32_t method_idx,
-                                              InvokeType type)
+// ArrayStoreException
+
+void ThrowArrayStoreException(const mirror::Class* element_class,
+                              const mirror::Class* array_class)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
-void ThrowNullPointerExceptionFromDexPC(mirror::AbstractMethod* throw_method, uint32_t dex_pc)
+// ClassCircularityError
+
+void ThrowClassCircularityError(mirror::Class* c) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+// ClassCastException
+
+void ThrowClassCastException(const mirror::Class* dest_type, const mirror::Class* src_type)
+    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+void ThrowClassCastException(const ThrowLocation* throw_location, const char* msg)
+    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+// ClassFormatError
+
+void ThrowClassFormatError(const mirror::Class* referrer, const char* fmt, ...)
+    __attribute__((__format__(__printf__, 2, 3)))
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
 // IllegalAccessError
@@ -62,6 +84,15 @@
                                        mirror::Field* accessed)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
+void ThrowIllegalAccessError(mirror::Class* referrer, const char* fmt, ...)
+    __attribute__((__format__(__printf__, 2, 3)))
+    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+// IllegalArgumentException
+
+void ThrowIllegalArgumentException(const ThrowLocation* throw_location, const char* msg)
+    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
 // IncompatibleClassChangeError
 
 void ThrowIncompatibleClassChangeError(InvokeType expected_type, InvokeType found_type,
@@ -78,13 +109,66 @@
                                             const mirror::AbstractMethod* referrer)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
+void ThrowIncompatibleClassChangeError(const mirror::Class* referrer, const char* fmt, ...)
+    __attribute__((__format__(__printf__, 2, 3)))
+    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+// LinkageError
+
+void ThrowLinkageError(const mirror::Class* referrer, const char* fmt, ...)
+    __attribute__((__format__(__printf__, 2, 3)))
+    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+// NegativeArraySizeException
+
+void ThrowNegativeArraySizeException(int size) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+void ThrowNegativeArraySizeException(const char* msg) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+
+// NoSuchFieldError
+
+void ThrowNoSuchFieldError(const StringPiece& scope, mirror::Class* c,
+                           const StringPiece& type, const StringPiece& name)
+    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
 // NoSuchMethodError
 
 void ThrowNoSuchMethodError(InvokeType type, mirror::Class* c, const StringPiece& name,
-                            const StringPiece& signature, const mirror::AbstractMethod* referrer)
+                            const StringPiece& signature)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
-void ThrowNoSuchMethodError(uint32_t method_idx, const mirror::AbstractMethod* referrer)
+void ThrowNoSuchMethodError(uint32_t method_idx)
+    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+// NullPointerException
+
+void ThrowNullPointerExceptionForFieldAccess(const ThrowLocation& throw_location,
+                                             mirror::Field* field,
+                                             bool is_read)
+    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+void ThrowNullPointerExceptionForMethodAccess(const ThrowLocation& throw_location,
+                                              uint32_t method_idx,
+                                              InvokeType type)
+    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+void ThrowNullPointerExceptionFromDexPC(const ThrowLocation& throw_location)
+    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+void ThrowNullPointerException(const ThrowLocation* throw_location, const char* msg)
+    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+// RuntimeException
+
+void ThrowRuntimeException(const char* fmt, ...)
+    __attribute__((__format__(__printf__, 1, 2)))
+    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+// VerifyError
+
+void ThrowVerifyError(const mirror::Class* referrer, const char* fmt, ...)
+    __attribute__((__format__(__printf__, 2, 3)))
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
 }  // namespace art
diff --git a/src/compiler/dex/frontend.h b/src/compiler/dex/frontend.h
index 2e62dc8..49e0852 100644
--- a/src/compiler/dex/frontend.h
+++ b/src/compiler/dex/frontend.h
@@ -55,7 +55,6 @@
 
 // Force code generation paths for testing.
 enum debugControlVector {
-  kDebugDisplayMissingTargets,
   kDebugVerbose,
   kDebugDumpCFG,
   kDebugSlowFieldPath,
diff --git a/src/compiler/dex/quick/gen_common.cc b/src/compiler/dex/quick/gen_common.cc
index c13e797..4fadc9d 100644
--- a/src/compiler/dex/quick/gen_common.cc
+++ b/src/compiler/dex/quick/gen_common.cc
@@ -507,17 +507,6 @@
   }
 }
 
-
-// Debugging routine - if null target, branch to DebugMe
-void Mir2Lir::GenShowTarget()
-{
-  DCHECK_NE(cu_->instruction_set, kX86) << "unimplemented GenShowTarget";
-  LIR* branch_over = OpCmpImmBranch(kCondNe, TargetReg(kInvokeTgt), 0, NULL);
-  LoadWordDisp(TargetReg(kSelf), ENTRYPOINT_OFFSET(pDebugMe), TargetReg(kInvokeTgt));
-  LIR* target = NewLIR0(kPseudoTargetLabel);
-  branch_over->target = target;
-}
-
 void Mir2Lir::HandleSuspendLaunchPads()
 {
   LIR** suspend_label = reinterpret_cast<LIR**>(suspend_launchpads_.elem_list);
diff --git a/src/compiler/dex/quick/gen_invoke.cc b/src/compiler/dex/quick/gen_invoke.cc
index 3e946f8..c0bae29 100644
--- a/src/compiler/dex/quick/gen_invoke.cc
+++ b/src/compiler/dex/quick/gen_invoke.cc
@@ -1375,9 +1375,6 @@
                              vtable_idx, direct_code, direct_method,
                              original_type);
   }
-  if (cu_->enable_debug & (1 << kDebugDisplayMissingTargets)) {
-    GenShowTarget();
-  }
   LIR* call_inst;
   if (cu_->instruction_set != kX86) {
     call_inst = OpReg(kOpBlx, TargetReg(kInvokeTgt));
diff --git a/src/compiler/dex/quick/mir_to_lir.h b/src/compiler/dex/quick/mir_to_lir.h
index 69ebc7e..aec0cc1 100644
--- a/src/compiler/dex/quick/mir_to_lir.h
+++ b/src/compiler/dex/quick/mir_to_lir.h
@@ -396,7 +396,6 @@
                  bool is_long_or_double, bool is_object);
     void GenSget(uint32_t field_idx, RegLocation rl_dest,
                  bool is_long_or_double, bool is_object);
-    void GenShowTarget();
     void GenIGet(uint32_t field_idx, int opt_flags, OpSize size,
                  RegLocation rl_dest, RegLocation rl_obj, bool is_long_or_double, bool is_object);
     void GenIPut(uint32_t field_idx, int opt_flags, OpSize size,
diff --git a/src/compiler/driver/compiler_driver.cc b/src/compiler/driver/compiler_driver.cc
index 700936c..4e8ebbd 100644
--- a/src/compiler/driver/compiler_driver.cc
+++ b/src/compiler/driver/compiler_driver.cc
@@ -1202,9 +1202,8 @@
       manager->GetClassLinker()->FindClass(descriptor,
                                            soa.Decode<mirror::ClassLoader*>(manager->GetClassLoader()));
   if (klass == NULL) {
-    Thread* self = Thread::Current();
-    CHECK(self->IsExceptionPending());
-    self->ClearException();
+    CHECK(soa.Self()->IsExceptionPending());
+    soa.Self()->ClearException();
 
     /*
      * At compile time, we can still structurally verify the class even if FindClass fails.
@@ -1230,13 +1229,13 @@
 
   if (klass->IsErroneous()) {
     // ClassLinker::VerifyClass throws, which isn't useful in the compiler.
-    CHECK(Thread::Current()->IsExceptionPending());
-    Thread::Current()->ClearException();
+    CHECK(soa.Self()->IsExceptionPending());
+    soa.Self()->ClearException();
   }
 
   CHECK(klass->IsCompileTimeVerified() || klass->IsErroneous())
       << PrettyDescriptor(klass) << ": state=" << klass->GetStatus();
-  CHECK(!Thread::Current()->IsExceptionPending()) << PrettyTypeOf(Thread::Current()->GetException());
+  soa.Self()->AssertNoPendingException();
 }
 
 void CompilerDriver::VerifyDexFile(jobject class_loader, const DexFile& dex_file,
@@ -1435,7 +1434,6 @@
   mirror::ClassLoader* class_loader = soa.Decode<mirror::ClassLoader*>(manager->GetClassLoader());
   const char* descriptor = manager->GetDexFile()->GetClassDescriptor(class_def);
   mirror::Class* klass = manager->GetClassLinker()->FindClass(descriptor, class_loader);
-  Thread* self = Thread::Current();
   bool compiling_boot = Runtime::Current()->GetHeap()->GetSpaces().size() == 1;
   bool can_init_static_fields = compiling_boot &&
       manager->GetCompiler()->IsImageClass(descriptor);
@@ -1447,9 +1445,9 @@
     // its parents, whose locks are acquired. This leads to a parent-to-child and a child-to-parent
     // lock ordering and consequent potential deadlock.
     static Mutex lock1("Initializer lock", kMonitorLock);
-    MutexLock mu(self, lock1);
+    MutexLock mu(soa.Self(), lock1);
     // The lock required to initialize the class.
-    ObjectLock lock2(self, klass);
+    ObjectLock lock2(soa.Self(), klass);
     // Only try to initialize classes that were successfully verified.
     if (klass->IsVerified()) {
       manager->GetClassLinker()->EnsureInitialized(klass, false, can_init_static_fields);
@@ -1473,7 +1471,7 @@
             } else {
               manager->GetClassLinker()->EnsureInitialized(klass, true, can_init_static_fields);
             }
-            CHECK(!self->IsExceptionPending()) << self->GetException()->Dump();
+            soa.Self()->AssertNoPendingException();
           }
         }
       }
@@ -1494,7 +1492,7 @@
     }
   }
   // Clear any class not found or verification exceptions.
-  self->ClearException();
+  soa.Self()->ClearException();
 }
 
 void CompilerDriver::InitializeClasses(jobject jni_class_loader, const DexFile& dex_file,
@@ -1651,7 +1649,7 @@
   if (self->IsExceptionPending()) {
     ScopedObjectAccess soa(self);
     LOG(FATAL) << "Unexpected exception compiling: " << PrettyMethod(method_idx, dex_file) << "\n"
-        << self->GetException()->Dump();
+        << self->GetException(NULL)->Dump();
   }
 }
 
diff --git a/src/compiler/llvm/runtime_support_llvm.cc b/src/compiler/llvm/runtime_support_llvm.cc
index d9b879a..d6c8181 100644
--- a/src/compiler/llvm/runtime_support_llvm.cc
+++ b/src/compiler/llvm/runtime_support_llvm.cc
@@ -135,15 +135,16 @@
   obj->MonitorExit(thread);
 }
 
-void art_portable_test_suspend_from_code(Thread* thread)
+void art_portable_test_suspend_from_code(Thread* self)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
-  CheckSuspend(thread);
-  if (thread->ReadFlag(kEnterInterpreter)) {
+  CheckSuspend(self);
+  if (Runtime::Current()->GetInstrumentation()->ShouldPortableCodeDeoptimize()) {
     // Save out the shadow frame to the heap
-    ShadowFrameCopyVisitor visitor(thread);
+    ShadowFrameCopyVisitor visitor(self);
     visitor.WalkStack(true);
-    thread->SetDeoptimizationShadowFrame(visitor.GetShadowFrameCopy(), JValue());
-    thread->SetException(reinterpret_cast<mirror::Throwable*>(-1));
+    self->SetDeoptimizationShadowFrame(visitor.GetShadowFrameCopy());
+    self->SetDeoptimizationReturnValue(JValue());
+    self->SetException(ThrowLocation(), reinterpret_cast<mirror::Throwable*>(-1));
   }
 }
 
@@ -175,51 +176,59 @@
 }
 
 void art_portable_throw_div_zero_from_code() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
-  Thread::Current()->ThrowNewException("Ljava/lang/ArithmeticException;",
-                                       "divide by zero");
+  ThrowArithmeticExceptionDivideByZero(Thread::Current());
 }
 
 void art_portable_throw_array_bounds_from_code(int32_t index, int32_t length)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
-  Thread::Current()->ThrowNewExceptionF("Ljava/lang/ArrayIndexOutOfBoundsException;",
-                                        "length=%d; index=%d", length, index);
+  ThrowArrayIndexOutOfBoundsException(index, length);
 }
 
 void art_portable_throw_no_such_method_from_code(int32_t method_idx)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
-  // We need the calling method as context for the method_idx.
-  mirror::AbstractMethod* method = Thread::Current()->GetCurrentMethod();
-  ThrowNoSuchMethodError(method_idx, method);
+  ThrowNoSuchMethodError(method_idx);
 }
 
 void art_portable_throw_null_pointer_exception_from_code(uint32_t dex_pc)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
-  mirror::AbstractMethod* throw_method =
-      Thread::Current()->GetManagedStack()->GetTopShadowFrame()->GetMethod();
-  ThrowNullPointerExceptionFromDexPC(throw_method, dex_pc);
+  // TODO: remove dex_pc argument from caller.
+  UNUSED(dex_pc);
+  Thread* self = Thread::Current();
+  ThrowLocation throw_location = self->GetCurrentLocationForThrow();
+  ThrowNullPointerExceptionFromDexPC(throw_location);
 }
 
 void art_portable_throw_stack_overflow_from_code() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
   ThrowStackOverflowError(Thread::Current());
 }
 
-void art_portable_throw_exception_from_code(mirror::Object* exception) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
-  Thread::Current()->DeliverException(static_cast<mirror::Throwable*>(exception));
+void art_portable_throw_exception_from_code(mirror::Throwable* exception)
+    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+  Thread* self = Thread::Current();
+  ThrowLocation throw_location = self->GetCurrentLocationForThrow();
+  if (exception == NULL) {
+    ThrowNullPointerException(NULL, "throw with null exception");
+  } else {
+    self->SetException(throw_location, exception);
+  }
 }
 
 void* art_portable_get_and_clear_exception(Thread* self)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
   DCHECK(self->IsExceptionPending());
-  mirror::Throwable* exception = self->GetException();
+  // TODO: make this inline.
+  mirror::Throwable* exception = self->GetException(NULL);
   self->ClearException();
   return exception;
 }
 
 int32_t art_portable_find_catch_block_from_code(mirror::AbstractMethod* current_method, uint32_t ti_offset)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
-  mirror::Throwable* exception = Thread::Current()->GetException();
-  // Check for magic deoptimization exception.
-  if (reinterpret_cast<int32_t>(exception) == -1) {
+  Thread* self = Thread::Current();  // TODO: make an argument.
+  ThrowLocation throw_location;
+  mirror::Throwable* exception = self->GetException(&throw_location);
+  // Check for special deoptimization exception.
+  if (UNLIKELY(reinterpret_cast<int32_t>(exception) == -1)) {
     return -1;
   }
   mirror::Class* exception_type = exception->GetClass();
@@ -229,26 +238,40 @@
   const DexFile::TryItem* try_item = DexFile::GetTryItems(*code_item, ti_offset);
 
   int iter_index = 0;
+  int result = -1;
+  uint32_t catch_dex_pc = -1;
   // Iterate over the catch handlers associated with dex_pc
   for (CatchHandlerIterator it(*code_item, *try_item); it.HasNext(); it.Next()) {
     uint16_t iter_type_idx = it.GetHandlerTypeIndex();
     // Catch all case
     if (iter_type_idx == DexFile::kDexNoIndex16) {
-      return iter_index;
+      catch_dex_pc = it.GetHandlerAddress();
+      result = iter_index;
+      break;
     }
     // Does this catch exception type apply?
     mirror::Class* iter_exception_type = mh.GetDexCacheResolvedType(iter_type_idx);
-    if (iter_exception_type == NULL) {
-      // The verifier should take care of resolving all exception classes early
+    if (UNLIKELY(iter_exception_type == NULL)) {
+      // TODO: check, the verifier (class linker?) should take care of resolving all exception
+      //       classes early.
       LOG(WARNING) << "Unresolved exception class when finding catch block: "
           << mh.GetTypeDescriptorFromTypeIdx(iter_type_idx);
     } else if (iter_exception_type->IsAssignableFrom(exception_type)) {
-      return iter_index;
+      catch_dex_pc = it.GetHandlerAddress();
+      result = iter_index;
+      break;
     }
     ++iter_index;
   }
-  // Handler not found
-  return -1;
+  if (result != -1) {
+    // Handler found.
+    Runtime::Current()->GetInstrumentation()->ExceptionCaughtEvent(self,
+                                                                   throw_location,
+                                                                   current_method,
+                                                                   catch_dex_pc,
+                                                                   exception);
+  }
+  return result;
 }
 
 
@@ -640,14 +663,12 @@
   DCHECK(dest_type->IsClass()) << PrettyClass(dest_type);
   DCHECK(src_type->IsClass()) << PrettyClass(src_type);
   if (UNLIKELY(!dest_type->IsAssignableFrom(src_type))) {
-    Thread::Current()->ThrowNewExceptionF("Ljava/lang/ClassCastException;",
-                                          "%s cannot be cast to %s",
-                                          PrettyDescriptor(src_type).c_str(),
-                                          PrettyDescriptor(dest_type).c_str());
+    ThrowClassCastException(dest_type, src_type);
   }
 }
 
-void art_portable_check_put_array_element_from_code(const mirror::Object* element, const mirror::Object* array)
+void art_portable_check_put_array_element_from_code(const mirror::Object* element,
+                                                    const mirror::Object* array)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
   if (element == NULL) {
     return;
@@ -658,10 +679,7 @@
   mirror::Class* component_type = array_class->GetComponentType();
   mirror::Class* element_class = element->GetClass();
   if (UNLIKELY(!component_type->IsAssignableFrom(element_class))) {
-    Thread::Current()->ThrowNewExceptionF("Ljava/lang/ArrayStoreException;",
-                                          "%s cannot be stored in an array of type %s",
-                                          PrettyDescriptor(element_class).c_str(),
-                                          PrettyDescriptor(array_class).c_str());
+    ThrowArrayStoreException(element_class, array_class);
   }
   return;
 }
diff --git a/src/debugger.cc b/src/debugger.cc
index 080288f..9bd1eb5 100644
--- a/src/debugger.cc
+++ b/src/debugger.cc
@@ -46,6 +46,7 @@
 #include "sirt_ref.h"
 #include "stack_indirect_reference_table.h"
 #include "thread_list.h"
+#include "throw_location.h"
 #include "utf.h"
 #include "well_known_classes.h"
 
@@ -104,6 +105,55 @@
   int stack_depth;
 };
 
+class DebugInstrumentationListener : public instrumentation::InstrumentationListener {
+ public:
+  DebugInstrumentationListener() {}
+  virtual ~DebugInstrumentationListener() {}
+
+  virtual void MethodEntered(Thread* thread, mirror::Object* this_object,
+                             const mirror::AbstractMethod* method, uint32_t dex_pc)
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+    if (method->IsNative()) {
+      // TODO: post location events is a suspension point and native method entry stubs aren't.
+      return;
+    }
+    Dbg::PostLocationEvent(method, 0, this_object, Dbg::kMethodEntry);
+  }
+
+  virtual void MethodExited(Thread* thread, mirror::Object* this_object,
+                            const mirror::AbstractMethod* method,
+                            uint32_t dex_pc, const JValue& return_value)
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+    UNUSED(return_value);
+    if (method->IsNative()) {
+      // TODO: post location events is a suspension point and native method entry stubs aren't.
+      return;
+    }
+    Dbg::PostLocationEvent(method, dex_pc, this_object, Dbg::kMethodExit);
+  }
+
+  virtual void MethodUnwind(Thread* thread, const mirror::AbstractMethod* method,
+                            uint32_t dex_pc) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+    // We're not recorded to listen to this kind of event, so complain.
+    LOG(ERROR) << "Unexpected method unwind event in debugger " << PrettyMethod(method)
+        << " " << dex_pc;
+  }
+
+  virtual void DexPcMoved(Thread* thread, mirror::Object* this_object,
+                          const mirror::AbstractMethod* method, uint32_t new_dex_pc)
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+    Dbg::UpdateDebugger(thread, this_object, method, new_dex_pc);
+  }
+
+  virtual void ExceptionCaught(Thread* thread, const ThrowLocation& throw_location,
+                               mirror::AbstractMethod* catch_method, uint32_t catch_dex_pc,
+                               mirror::Throwable* exception_object)
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+    Dbg::PostException(thread, throw_location, catch_method, catch_dex_pc, exception_object);
+  }
+
+} gDebugInstrumentationListener;
+
 // JDWP is allowed unless the Zygote forbids it.
 static bool gJdwpAllowed = true;
 
@@ -140,7 +190,7 @@
 static std::vector<Breakpoint> gBreakpoints GUARDED_BY(Locks::breakpoint_lock_);
 static SingleStepControl gSingleStepControl GUARDED_BY(Locks::breakpoint_lock_);
 
-static bool IsBreakpoint(mirror::AbstractMethod* m, uint32_t dex_pc)
+static bool IsBreakpoint(const mirror::AbstractMethod* m, uint32_t dex_pc)
     LOCKS_EXCLUDED(Locks::breakpoint_lock_)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
   MutexLock mu(Thread::Current(), *Locks::breakpoint_lock_);
@@ -466,15 +516,6 @@
   return gDisposed;
 }
 
-static void SetDebuggerUpdatesEnabledCallback(Thread* t, void* user_data) {
-  t->SetDebuggerUpdatesEnabled(*reinterpret_cast<bool*>(user_data));
-}
-
-static void SetDebuggerUpdatesEnabled(bool enabled) {
-  MutexLock mu(Thread::Current(), *Locks::thread_list_lock_);
-  Runtime::Current()->GetThreadList()->ForEach(SetDebuggerUpdatesEnabledCallback, &enabled);
-}
-
 void Dbg::GoActive() {
   // Enable all debugging features, including scans for breakpoints.
   // This is a no-op if we're already active.
@@ -483,16 +524,26 @@
     return;
   }
 
-  LOG(INFO) << "Debugger is active";
-
   {
     // TODO: dalvik only warned if there were breakpoints left over. clear in Dbg::Disconnected?
     MutexLock mu(Thread::Current(), *Locks::breakpoint_lock_);
     CHECK_EQ(gBreakpoints.size(), 0U);
   }
 
+  Runtime* runtime = Runtime::Current();
+  runtime->GetThreadList()->SuspendAll();
+  Thread* self = Thread::Current();
+  ThreadState old_state = self->SetStateUnsafe(kRunnable);
+  CHECK_NE(old_state, kRunnable);
+  runtime->GetInstrumentation()->AddListener(&gDebugInstrumentationListener,
+                                             instrumentation::Instrumentation::kMethodEntered |
+                                             instrumentation::Instrumentation::kMethodExited |
+                                             instrumentation::Instrumentation::kDexPcMoved);
   gDebuggerActive = true;
-  SetDebuggerUpdatesEnabled(true);
+  CHECK_EQ(self->SetStateUnsafe(old_state), kRunnable);
+  runtime->GetThreadList()->ResumeAll();
+
+  LOG(INFO) << "Debugger is active";
 }
 
 void Dbg::Disconnected() {
@@ -500,11 +551,22 @@
 
   LOG(INFO) << "Debugger is no longer active";
 
+  // Suspend all threads and exclusively acquire the mutator lock. Set the state of the thread
+  // to kRunnable to avoid scoped object access transitions. Remove the debugger as a listener
+  // and clear the object registry.
+  Runtime* runtime = Runtime::Current();
+  runtime->GetThreadList()->SuspendAll();
+  Thread* self = Thread::Current();
+  ThreadState old_state = self->SetStateUnsafe(kRunnable);
+  runtime->GetInstrumentation()->RemoveListener(&gDebugInstrumentationListener,
+                                                instrumentation::Instrumentation::kMethodEntered |
+                                                instrumentation::Instrumentation::kMethodExited |
+                                                instrumentation::Instrumentation::kDexPcMoved);
   gDebuggerActive = false;
-  SetDebuggerUpdatesEnabled(false);
-
   gRegistry->Clear();
   gDebuggerConnected = false;
+  CHECK_EQ(self->SetStateUnsafe(old_state), kRunnable);
+  runtime->GetThreadList()->ResumeAll();
 }
 
 bool Dbg::IsDebuggerActive() {
@@ -1902,34 +1964,16 @@
   virtual bool VisitFrame() NO_THREAD_SAFETY_ANALYSIS {
     if (frame_id != GetFrameId()) {
       return true;  // continue
-    }
-    mirror::AbstractMethod* m = GetMethod();
-    if (m->IsNative() || m->IsStatic()) {
-      this_object = NULL;
     } else {
-      uint16_t reg = DemangleSlot(0, m);
-      this_object = reinterpret_cast<mirror::Object*>(GetVReg(m, reg, kReferenceVReg));
+      this_object = GetThisObject();
+      return false;
     }
-    return false;
   }
 
   mirror::Object* this_object;
   JDWP::FrameId frame_id;
 };
 
-static mirror::Object* GetThis(Thread* self, mirror::AbstractMethod* m, size_t frame_id)
-    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
-  // TODO: should we return the 'this' we passed through to non-static native methods?
-  if (m->IsNative() || m->IsStatic()) {
-    return NULL;
-  }
-
-  UniquePtr<Context> context(Context::Create());
-  GetThisVisitor visitor(self, context.get(), frame_id);
-  visitor.WalkStack();
-  return visitor.this_object;
-}
-
 JDWP::JdwpError Dbg::GetThisObject(JDWP::ObjectId thread_id, JDWP::FrameId frame_id,
                                    JDWP::ObjectId* result) {
   ScopedObjectAccessUnchecked soa(Thread::Current());
@@ -2176,7 +2220,8 @@
   visitor.WalkStack();
 }
 
-void Dbg::PostLocationEvent(const mirror::AbstractMethod* m, int dex_pc, mirror::Object* this_object, int event_flags) {
+void Dbg::PostLocationEvent(const mirror::AbstractMethod* m, int dex_pc,
+                            mirror::Object* this_object, int event_flags) {
   mirror::Class* c = m->GetDeclaringClass();
 
   JDWP::JdwpLocation location;
@@ -2194,29 +2239,25 @@
   gJdwpState->PostLocationEvent(&location, this_id, event_flags);
 }
 
-void Dbg::PostException(Thread* thread,
-                        JDWP::FrameId throw_frame_id, mirror::AbstractMethod* throw_method,
-                        uint32_t throw_dex_pc, mirror::AbstractMethod* catch_method,
+void Dbg::PostException(Thread* thread, const ThrowLocation& throw_location,
+                        mirror::AbstractMethod* catch_method,
                         uint32_t catch_dex_pc, mirror::Throwable* exception_object) {
   if (!IsDebuggerActive()) {
     return;
   }
 
-  JDWP::JdwpLocation throw_location;
-  SetLocation(throw_location, throw_method, throw_dex_pc);
+  JDWP::JdwpLocation jdwp_throw_location;
+  SetLocation(jdwp_throw_location, throw_location.GetMethod(), throw_location.GetDexPc());
   JDWP::JdwpLocation catch_location;
   SetLocation(catch_location, catch_method, catch_dex_pc);
 
   // We need 'this' for InstanceOnly filters.
-  UniquePtr<Context> context(Context::Create());
-  GetThisVisitor visitor(thread, context.get(), throw_frame_id);
-  visitor.WalkStack();
-  JDWP::ObjectId this_id = gRegistry->Add(visitor.this_object);
-
+  JDWP::ObjectId this_id = gRegistry->Add(throw_location.GetThis());
   JDWP::ObjectId exception_id = gRegistry->Add(exception_object);
   JDWP::RefTypeId exception_class_id = gRegistry->AddRefType(exception_object->GetClass());
 
-  gJdwpState->PostException(&throw_location, exception_id, exception_class_id, &catch_location, this_id);
+  gJdwpState->PostException(&jdwp_throw_location, exception_id, exception_class_id, &catch_location,
+                            this_id);
 }
 
 void Dbg::PostClassPrepare(mirror::Class* c) {
@@ -2232,20 +2273,9 @@
   gJdwpState->PostClassPrepare(tag, gRegistry->Add(c), ClassHelper(c).GetDescriptor(), state);
 }
 
-void Dbg::UpdateDebugger(int32_t dex_pc, Thread* self) {
-  if (!IsDebuggerActive() || dex_pc == -2 /* fake method exit */) {
-    return;
-  }
-
-  size_t frame_id;
-  mirror::AbstractMethod* m = self->GetCurrentMethod(NULL, &frame_id);
-  //LOG(INFO) << "UpdateDebugger " << PrettyMethod(m) << "@" << dex_pc << " frame " << frame_id;
-
-  if (dex_pc == -1) {
-    // We use a pc of -1 to represent method entry, since we might branch back to pc 0 later.
-    // This means that for this special notification, there can't be anything else interesting
-    // going on, so we're done already.
-    Dbg::PostLocationEvent(m, 0, GetThis(self, m, frame_id), kMethodEntry);
+void Dbg::UpdateDebugger(Thread* thread, mirror::Object* this_object,
+                         const mirror::AbstractMethod* m, uint32_t dex_pc) {
+  if (!IsDebuggerActive() || dex_pc == static_cast<uint32_t>(-2) /* fake method exit */) {
     return;
   }
 
@@ -2259,7 +2289,7 @@
     // If the debugger is single-stepping one of our threads, check to
     // see if we're that thread and we've reached a step point.
     MutexLock mu(Thread::Current(), *Locks::breakpoint_lock_);
-    if (gSingleStepControl.is_active && gSingleStepControl.thread == self) {
+    if (gSingleStepControl.is_active && gSingleStepControl.thread == thread) {
       CHECK(!m->IsNative());
       if (gSingleStepControl.step_depth == JDWP::SD_INTO) {
         // Step into method calls.  We break when the line number
@@ -2282,7 +2312,7 @@
         // might get unrolled past it by an exception, and it's tricky
         // to identify recursion.)
 
-        int stack_depth = GetStackDepth(self);
+        int stack_depth = GetStackDepth(thread);
 
         if (stack_depth < gSingleStepControl.stack_depth) {
           // popped up one or more frames, always trigger
@@ -2307,7 +2337,7 @@
         // with the PC at the next instruction in the returned-to
         // function, rather than the end of the returning function.
 
-        int stack_depth = GetStackDepth(self);
+        int stack_depth = GetStackDepth(thread);
         if (stack_depth < gSingleStepControl.stack_depth) {
           event_flags |= kSingleStep;
           VLOG(jdwp) << "SS method pop";
@@ -2316,27 +2346,10 @@
     }
   }
 
-  // Check to see if this is a "return" instruction.  JDWP says we should
-  // send the event *after* the code has been executed, but it also says
-  // the location we provide is the last instruction.  Since the "return"
-  // instruction has no interesting side effects, we should be safe.
-  // (We can't just move this down to the returnFromMethod label because
-  // we potentially need to combine it with other events.)
-  // We're also not supposed to generate a method exit event if the method
-  // terminates "with a thrown exception".
-  if (dex_pc >= 0) {
-    const DexFile::CodeItem* code_item = MethodHelper(m).GetCodeItem();
-    CHECK(code_item != NULL) << PrettyMethod(m) << " @" << dex_pc;
-    CHECK_LT(dex_pc, static_cast<int32_t>(code_item->insns_size_in_code_units_));
-    if (Instruction::At(&code_item->insns_[dex_pc])->IsReturn()) {
-      event_flags |= kMethodExit;
-    }
-  }
-
   // If there's something interesting going on, see if it matches one
   // of the debugger filters.
   if (event_flags != 0) {
-    Dbg::PostLocationEvent(m, dex_pc, GetThis(self, m, frame_id), event_flags);
+    Dbg::PostLocationEvent(m, dex_pc, this_object, event_flags);
   }
 }
 
@@ -2706,8 +2719,19 @@
 
   // We can be called while an exception is pending. We need
   // to preserve that across the method invocation.
-  SirtRef<mirror::Throwable> old_exception(soa.Self(), soa.Self()->GetException());
-  soa.Self()->ClearException();
+  SirtRef<mirror::Object> old_throw_this_object(soa.Self(), NULL);
+  SirtRef<mirror::AbstractMethod> old_throw_method(soa.Self(), NULL);
+  SirtRef<mirror::Throwable> old_exception(soa.Self(), NULL);
+  uint32_t old_throw_dex_pc;
+  {
+    ThrowLocation old_throw_location;
+    mirror::Throwable* old_exception_obj = soa.Self()->GetException(&old_throw_location);
+    old_throw_this_object.reset(old_throw_location.GetThis());
+    old_throw_method.reset(old_throw_location.GetMethod());
+    old_exception.reset(old_exception_obj);
+    old_throw_dex_pc = old_throw_location.GetDexPc();
+    soa.Self()->ClearException();
+  }
 
   // Translate the method through the vtable, unless the debugger wants to suppress it.
   mirror::AbstractMethod* m = pReq->method_;
@@ -2731,12 +2755,13 @@
   arg_array.BuildArgArray(soa, pReq->receiver_, reinterpret_cast<jvalue*>(pReq->arg_values_));
   InvokeWithArgArray(soa, m, &arg_array, &pReq->result_value, mh.GetShorty()[0]);
 
-  pReq->exception = gRegistry->Add(soa.Self()->GetException());
+  mirror::Throwable* exception = soa.Self()->GetException(NULL);
+  soa.Self()->ClearException();
+  pReq->exception = gRegistry->Add(exception);
   pReq->result_tag = BasicTagFromDescriptor(MethodHelper(m).GetShorty());
   if (pReq->exception != 0) {
-    mirror::Object* exc = soa.Self()->GetException();
-    VLOG(jdwp) << "  JDWP invocation returning with exception=" << exc << " " << PrettyTypeOf(exc);
-    soa.Self()->ClearException();
+    VLOG(jdwp) << "  JDWP invocation returning with exception=" << exception
+        << " " << exception->Dump();
     pReq->result_value.SetJ(0);
   } else if (pReq->result_tag == JDWP::JT_OBJECT) {
     /* if no exception thrown, examine object result more closely */
@@ -2759,7 +2784,9 @@
   }
 
   if (old_exception.get() != NULL) {
-    soa.Self()->SetException(old_exception.get());
+    ThrowLocation gc_safe_throw_location(old_throw_this_object.get(), old_throw_method.get(),
+                                         old_throw_dex_pc);
+    soa.Self()->SetException(gc_safe_throw_location, old_exception.get());
   }
 }
 
@@ -2943,9 +2970,6 @@
     ScopedObjectAccessUnchecked soa(Thread::Current());
     JDWP::ObjectId id = gRegistry->Add(t->GetPeer());
     gJdwpState->PostThreadChange(id, type == CHUNK_TYPE("THCR"));
-    // If this thread's just joined the party while we're already debugging, make sure it knows
-    // to give us updates when it's running.
-    t->SetDebuggerUpdatesEnabled(true);
   }
   Dbg::DdmSendThreadNotification(t, type);
 }
@@ -3326,9 +3350,9 @@
     Heap* heap = Runtime::Current()->GetHeap();
     const Spaces& spaces = heap->GetSpaces();
     Thread* self = Thread::Current();
+    ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_);
     for (Spaces::const_iterator cur = spaces.begin(); cur != spaces.end(); ++cur) {
       if ((*cur)->IsAllocSpace()) {
-        ReaderMutexLock mu(self, *Locks::heap_bitmap_lock_);
         (*cur)->AsAllocSpace()->Walk(HeapChunkContext::HeapChunkCallback, &context);
       }
     }
diff --git a/src/debugger.h b/src/debugger.h
index ad01011..eb17695 100644
--- a/src/debugger.h
+++ b/src/debugger.h
@@ -39,6 +39,7 @@
 }  // namespace mirror
 struct AllocRecord;
 class Thread;
+class ThrowLocation;
 
 /*
  * Invoke-during-breakpoint support.
@@ -101,8 +102,8 @@
    * when the debugger attaches.
    */
   static void Connected();
-  static void GoActive() LOCKS_EXCLUDED(Locks::breakpoint_lock_);
-  static void Disconnected() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+  static void GoActive() LOCKS_EXCLUDED(Locks::breakpoint_lock_, Locks::mutator_lock_);
+  static void Disconnected() LOCKS_EXCLUDED(Locks::mutator_lock_);
   static void Disposed();
 
   // Returns true if we're actually debugging with a real debugger, false if it's
@@ -326,9 +327,8 @@
   static void PostLocationEvent(const mirror::AbstractMethod* method, int pcOffset,
                                 mirror::Object* thisPtr, int eventFlags)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
-  static void PostException(Thread* thread, JDWP::FrameId throw_frame_id,
-                            mirror::AbstractMethod* throw_method,
-                            uint32_t throw_dex_pc, mirror::AbstractMethod* catch_method,
+  static void PostException(Thread* thread, const ThrowLocation& throw_location,
+                            mirror::AbstractMethod* catch_method,
                             uint32_t catch_dex_pc, mirror::Throwable* exception)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
   static void PostThreadStart(Thread* t)
@@ -338,7 +338,8 @@
   static void PostClassPrepare(mirror::Class* c)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
-  static void UpdateDebugger(int32_t dex_pc, Thread* self)
+  static void UpdateDebugger(Thread* thread, mirror::Object* this_object,
+                             const mirror::AbstractMethod* method, uint32_t new_dex_pc)
       LOCKS_EXCLUDED(Locks::breakpoint_lock_)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
diff --git a/src/dex_file.h b/src/dex_file.h
index 2da3e32..002d79c 100644
--- a/src/dex_file.h
+++ b/src/dex_file.h
@@ -866,10 +866,10 @@
   Index index_;
 
   // The base address of the memory mapping.
-  const byte* begin_;
+  const byte* const begin_;
 
   // The size of the underlying memory allocation in bytes.
-  size_t size_;
+  const size_t size_;
 
   // Typically the dex file name when available, alternatively some identifying string.
   //
@@ -883,6 +883,7 @@
   UniquePtr<MemMap> mem_map_;
 
   // A cached com.android.dex.Dex instance, possibly NULL. Use GetDexObject.
+  // TODO: this is mutable as it shouldn't be here. We should move it to the dex cache or similar.
   mutable jobject dex_object_;
 
   // Points to the header section.
diff --git a/src/gc/large_object_space.cc b/src/gc/large_object_space.cc
index df7e68d..c3bf382 100644
--- a/src/gc/large_object_space.cc
+++ b/src/gc/large_object_space.cc
@@ -50,7 +50,7 @@
 
 LargeObjectMapSpace::LargeObjectMapSpace(const std::string& name)
     : LargeObjectSpace(name),
-      lock_("large object space lock", kAllocSpaceLock)
+      lock_("large object map space lock", kAllocSpaceLock)
 {
 
 }
diff --git a/src/gc/mark_sweep.cc b/src/gc/mark_sweep.cc
index 055a7e7..35e75cb 100644
--- a/src/gc/mark_sweep.cc
+++ b/src/gc/mark_sweep.cc
@@ -135,8 +135,8 @@
 MarkSweep::MarkSweep(Heap* heap, bool is_concurrent)
     : GarbageCollector(heap),
       gc_barrier_(new Barrier(0)),
-      large_object_lock_("large object lock"),
-      mark_stack_expand_lock_("mark stack expand lock"),
+      large_object_lock_("mark sweep large object lock", kMarkSweepLargeObjectLock),
+      mark_stack_expand_lock_("mark sweep mark stack expand lock"),
       timings_(GetName(), true),
       cumulative_timings_(GetName()),
       is_concurrent_(is_concurrent) {
diff --git a/src/gc_map.h b/src/gc_map.h
index 8e4dbdb..473b39a 100644
--- a/src/gc_map.h
+++ b/src/gc_map.h
@@ -66,8 +66,11 @@
   const uint8_t* FindBitMap(uintptr_t native_pc_offset) {
     size_t num_entries = NumEntries();
     size_t index = Hash(native_pc_offset) % num_entries;
+    size_t misses = 0;
     while (GetNativePcOffset(index) != native_pc_offset) {
       index = (index + 1) % num_entries;
+      misses++;
+      DCHECK_LT(misses, num_entries) << "Failed to find offset: " << native_pc_offset;
     }
     return GetBitMap(index);
   }
diff --git a/src/heap.cc b/src/heap.cc
index 2f7cb24..468e800 100644
--- a/src/heap.cc
+++ b/src/heap.cc
@@ -611,44 +611,46 @@
 }
 
 void Heap::VerifyObjectBody(const mirror::Object* obj) {
-  if (!IsAligned<kObjectAlignment>(obj)) {
+  if (UNLIKELY(!IsAligned<kObjectAlignment>(obj))) {
     LOG(FATAL) << "Object isn't aligned: " << obj;
   }
+  if (UNLIKELY(GetObjectsAllocated() <= 10)) {  // Ignore early dawn of the universe verifications.
+    return;
+  }
+  const byte* raw_addr = reinterpret_cast<const byte*>(obj) +
+      mirror::Object::ClassOffset().Int32Value();
+  const mirror::Class* c = *reinterpret_cast<mirror::Class* const *>(raw_addr);
+  if (UNLIKELY(c == NULL)) {
+    LOG(FATAL) << "Null class in object: " << obj;
+  } else if (UNLIKELY(!IsAligned<kObjectAlignment>(c))) {
+    LOG(FATAL) << "Class isn't aligned: " << c << " in object: " << obj;
+  }
+  // Check obj.getClass().getClass() == obj.getClass().getClass().getClass()
+  // Note: we don't use the accessors here as they have internal sanity checks
+  // that we don't want to run
+  raw_addr = reinterpret_cast<const byte*>(c) + mirror::Object::ClassOffset().Int32Value();
+  const mirror::Class* c_c = *reinterpret_cast<mirror::Class* const *>(raw_addr);
+  raw_addr = reinterpret_cast<const byte*>(c_c) + mirror::Object::ClassOffset().Int32Value();
+  const mirror::Class* c_c_c = *reinterpret_cast<mirror::Class* const *>(raw_addr);
+  CHECK_EQ(c_c, c_c_c);
 
-  // TODO: the bitmap tests below are racy if VerifyObjectBody is called without the
-  //       heap_bitmap_lock_.
-  if (!GetLiveBitmap()->Test(obj)) {
-    // Check the allocation stack / live stack.
-    if (!std::binary_search(live_stack_->Begin(), live_stack_->End(), obj) &&
-        std::find(allocation_stack_->Begin(), allocation_stack_->End(), obj) ==
-            allocation_stack_->End()) {
-      if (large_object_space_->GetLiveObjects()->Test(obj)) {
-        DumpSpaces();
-        LOG(FATAL) << "Object is dead: " << obj;
+  if (verify_object_mode_ != kVerifyAllFast) {
+    // TODO: the bitmap tests below are racy if VerifyObjectBody is called without the
+    //       heap_bitmap_lock_.
+    if (!GetLiveBitmap()->Test(obj)) {
+      // Check the allocation stack / live stack.
+      if (!std::binary_search(live_stack_->Begin(), live_stack_->End(), obj) &&
+          std::find(allocation_stack_->Begin(), allocation_stack_->End(), obj) ==
+              allocation_stack_->End()) {
+        if (large_object_space_->GetLiveObjects()->Test(obj)) {
+          DumpSpaces();
+          LOG(FATAL) << "Object is dead: " << obj;
+        }
       }
     }
-  }
-
-  // Ignore early dawn of the universe verifications
-  if (verify_object_mode_ != kVerifyAllFast && GetObjectsAllocated() > 10) {
-    const byte* raw_addr = reinterpret_cast<const byte*>(obj) +
-        mirror::Object::ClassOffset().Int32Value();
-    const mirror::Class* c = *reinterpret_cast<mirror::Class* const *>(raw_addr);
-    if (c == NULL) {
-      LOG(FATAL) << "Null class in object: " << obj;
-    } else if (!IsAligned<kObjectAlignment>(c)) {
-      LOG(FATAL) << "Class isn't aligned: " << c << " in object: " << obj;
-    } else if (!GetLiveBitmap()->Test(c)) {
+    if (!GetLiveBitmap()->Test(c)) {
       LOG(FATAL) << "Class of object is dead: " << c << " in object: " << obj;
     }
-    // Check obj.getClass().getClass() == obj.getClass().getClass().getClass()
-    // Note: we don't use the accessors here as they have internal sanity checks
-    // that we don't want to run
-    raw_addr = reinterpret_cast<const byte*>(c) + mirror::Object::ClassOffset().Int32Value();
-    const mirror::Class* c_c = *reinterpret_cast<mirror::Class* const *>(raw_addr);
-    raw_addr = reinterpret_cast<const byte*>(c_c) + mirror::Object::ClassOffset().Int32Value();
-    const mirror::Class* c_c_c = *reinterpret_cast<mirror::Class* const *>(raw_addr);
-    CHECK_EQ(c_c, c_c_c);
   }
 }
 
diff --git a/src/hprof/hprof.cc b/src/hprof/hprof.cc
index 472cc67..7539066 100644
--- a/src/hprof/hprof.cc
+++ b/src/hprof/hprof.cc
@@ -41,6 +41,7 @@
 #include "base/stringprintf.h"
 #include "base/unix_file/fd_file.h"
 #include "class_linker.h"
+#include "common_throws.h"
 #include "debugger.h"
 #include "dex_file-inl.h"
 #include "globals.h"
@@ -450,16 +451,14 @@
       if (fd_ >= 0) {
         out_fd = dup(fd_);
         if (out_fd < 0) {
-          self->ThrowNewExceptionF("Ljava/lang/RuntimeException;",
-                                   "Couldn't dump heap; dup(%d) failed: %s", fd_, strerror(errno));
+          ThrowRuntimeException("Couldn't dump heap; dup(%d) failed: %s", fd_, strerror(errno));
           return;
         }
       } else {
         out_fd = open(filename_.c_str(), O_WRONLY|O_CREAT|O_TRUNC, 0644);
         if (out_fd < 0) {
-          self->ThrowNewExceptionF("Ljava/lang/RuntimeException;",
-                                   "Couldn't dump heap; open(\"%s\") failed: %s", filename_.c_str(),
-                                   strerror(errno));
+          ThrowRuntimeException("Couldn't dump heap; open(\"%s\") failed: %s", filename_.c_str(),
+                                strerror(errno));
           return;
         }
       }
@@ -470,7 +469,7 @@
       if (!okay) {
         std::string msg(StringPrintf("Couldn't dump heap; writing \"%s\" failed: %s",
                                      filename_.c_str(), strerror(errno)));
-        self->ThrowNewException("Ljava/lang/RuntimeException;", msg.c_str());
+        ThrowRuntimeException("%s", msg.c_str());
         LOG(ERROR) << msg;
       }
     }
diff --git a/src/instrumentation.cc b/src/instrumentation.cc
index 81fe637..55e93cb 100644
--- a/src/instrumentation.cc
+++ b/src/instrumentation.cc
@@ -18,14 +18,17 @@
 
 #include <sys/uio.h>
 
+#include "atomic_integer.h"
 #include "base/unix_file/fd_file.h"
 #include "class_linker.h"
 #include "debugger.h"
+#include "dex_file-inl.h"
 #include "mirror/class-inl.h"
 #include "mirror/dex_cache.h"
 #include "mirror/abstract_method-inl.h"
 #include "mirror/object_array-inl.h"
 #include "mirror/object-inl.h"
+#include "nth_caller_visitor.h"
 #if !defined(ART_USE_PORTABLE_COMPILER)
 #include "oat/runtime/oat_support_entrypoints.h"
 #endif
@@ -34,205 +37,521 @@
 #include "scoped_thread_state_change.h"
 #include "thread.h"
 #include "thread_list.h"
-#include "trace.h"
 
 namespace art {
+namespace instrumentation {
 
-static bool InstallStubsClassVisitor(mirror::Class* klass, void*)
+static bool InstallStubsClassVisitor(mirror::Class* klass, void* arg)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
-  Instrumentation* instrumentation = Runtime::Current()->GetInstrumentation();
+  Instrumentation* instrumentation = reinterpret_cast<Instrumentation*>(arg);
+  return instrumentation->InstallStubsForClass(klass);
+}
+
+bool Instrumentation::InstallStubsForClass(mirror::Class* klass) {
+  bool uninstall = !entry_exit_stubs_installed_ && !interpreter_stubs_installed_;
+  ClassLinker* class_linker = NULL;
+  if (uninstall) {
+    class_linker = Runtime::Current()->GetClassLinker();
+  }
+  bool is_initialized = klass->IsInitialized();
   for (size_t i = 0; i < klass->NumDirectMethods(); i++) {
     mirror::AbstractMethod* method = klass->GetDirectMethod(i);
-    if (instrumentation->GetSavedCodeFromMap(method) == NULL) {
-      instrumentation->SaveAndUpdateCode(method);
+    if (!method->IsAbstract()) {
+      const void* new_code;
+      if (uninstall) {
+        if (is_initialized || !method->IsStatic() || method->IsConstructor()) {
+          new_code = class_linker->GetOatCodeFor(method);
+        } else {
+          new_code = Runtime::Current()->GetResolutionStubArray(Runtime::kStaticMethod)->GetData();
+        }
+      } else {  // !uninstall
+        if (!interpreter_stubs_installed_ || method->IsNative()) {
+          new_code = GetInstrumentationEntryPoint();
+        } else {
+          new_code = GetInterpreterEntryPoint();
+        }
+      }
+      method->SetCode(new_code);
     }
   }
-
   for (size_t i = 0; i < klass->NumVirtualMethods(); i++) {
     mirror::AbstractMethod* method = klass->GetVirtualMethod(i);
-    if (instrumentation->GetSavedCodeFromMap(method) == NULL) {
-      instrumentation->SaveAndUpdateCode(method);
+    if (!method->IsAbstract()) {
+      const void* new_code;
+      if (uninstall) {
+        new_code = class_linker->GetOatCodeFor(method);
+      } else {  // !uninstall
+        if (!interpreter_stubs_installed_ || method->IsNative()) {
+          new_code = GetInstrumentationEntryPoint();
+        } else {
+          new_code = GetInterpreterEntryPoint();
+        }
+      }
+      method->SetCode(new_code);
     }
   }
   return true;
 }
 
-static bool UninstallStubsClassVisitor(mirror::Class* klass, void*)
-    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
-  Instrumentation* instrumentation = Runtime::Current()->GetInstrumentation();
-  for (size_t i = 0; i < klass->NumDirectMethods(); i++) {
-    mirror::AbstractMethod* method = klass->GetDirectMethod(i);
-    if (instrumentation->GetSavedCodeFromMap(method) != NULL) {
-      instrumentation->ResetSavedCode(method);
-    }
-  }
-
-  for (size_t i = 0; i < klass->NumVirtualMethods(); i++) {
-    mirror::AbstractMethod* method = klass->GetVirtualMethod(i);
-    if (instrumentation->GetSavedCodeFromMap(method) != NULL) {
-      instrumentation->ResetSavedCode(method);
-    }
-  }
-  return true;
-}
-
-void InstrumentationInstallStack(Thread* self, void* arg)
+// Places the instrumentation exit pc as the return PC for every quick frame. This also allows
+// deoptimization of quick frames to interpreter frames.
+static void InstrumentationInstallStack(Thread* thread, void* arg)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
   struct InstallStackVisitor : public StackVisitor {
-    InstallStackVisitor(Thread* self, uintptr_t instrumentation_exit_pc)
-        : StackVisitor(self, NULL),  self_(self),
-          instrumentation_exit_pc_(instrumentation_exit_pc) {}
+    InstallStackVisitor(Thread* thread, Context* context, uintptr_t instrumentation_exit_pc)
+        : StackVisitor(thread, context),  instrumentation_stack_(thread->GetInstrumentationStack()),
+          instrumentation_exit_pc_(instrumentation_exit_pc), last_return_pc_(0) {}
 
     virtual bool VisitFrame() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+      mirror::AbstractMethod* m = GetMethod();
       if (GetCurrentQuickFrame() == NULL) {
+        if (kVerboseInstrumentation) {
+          LOG(INFO) << "  Ignoring a shadow frame. Frame " << GetFrameId()
+              << " Method=" << PrettyMethod(m);
+        }
         return true;  // Ignore shadow frames.
       }
-      mirror::AbstractMethod* m = GetMethod();
       if (m == NULL) {
+        if (kVerboseInstrumentation) {
+          LOG(INFO) << "  Skipping upcall. Frame " << GetFrameId();
+        }
+        last_return_pc_ = 0;
         return true; // Ignore upcalls.
       }
-      if (m->GetDexMethodIndex() == DexFile::kDexNoIndex16) {
+      if (m->IsRuntimeMethod()) {
+        if (kVerboseInstrumentation) {
+          LOG(INFO) << "  Skipping runtime method. Frame " << GetFrameId();
+        }
+        last_return_pc_ = GetReturnPc();
         return true;  // Ignore unresolved methods since they will be instrumented after resolution.
       }
-      uintptr_t pc = GetReturnPc();
-      InstrumentationStackFrame instrumentation_frame(m, pc, GetFrameId());
-      self_->PushBackInstrumentationStackFrame(instrumentation_frame);
+      if (kVerboseInstrumentation) {
+        LOG(INFO) << "  Installing exit stub in " << DescribeLocation();
+      }
+      uintptr_t return_pc = GetReturnPc();
+      CHECK_NE(return_pc, instrumentation_exit_pc_);
+      CHECK_NE(return_pc, 0U);
+      InstrumentationStackFrame instrumentation_frame(GetThisObject(), m, return_pc, GetFrameId());
+      if (kVerboseInstrumentation) {
+        LOG(INFO) << "Pushing frame " << instrumentation_frame.Dump();
+      }
+      instrumentation_stack_->push_back(instrumentation_frame);
+      dex_pcs_.push_back(m->ToDexPc(last_return_pc_));
       SetReturnPc(instrumentation_exit_pc_);
+      last_return_pc_ = return_pc;
       return true;  // Continue.
     }
-    Thread* const self_;
+    std::deque<InstrumentationStackFrame>* const instrumentation_stack_;
+    std::vector<uint32_t> dex_pcs_;
     const uintptr_t instrumentation_exit_pc_;
+    uintptr_t last_return_pc_;
   };
-  uintptr_t instrumentation_exit_pc = GetInstrumentationExitPc();
-  InstallStackVisitor visitor(self, instrumentation_exit_pc);
-  visitor.WalkStack(true);
-  Trace* trace = reinterpret_cast<Trace*>(arg);
-  if (trace != NULL) {
-    std::deque<InstrumentationStackFrame>::const_reverse_iterator it =
-        self->GetInstrumentationStack()->rbegin();
-    std::deque<InstrumentationStackFrame>::const_reverse_iterator end =
-        self->GetInstrumentationStack()->rend();
-    for (; it != end; ++it) {
-      trace->LogMethodTraceEvent(self, (*it).method_, Trace::kMethodTraceEnter);
-    }
+  if (kVerboseInstrumentation) {
+    std::string thread_name;
+    thread->GetThreadName(thread_name);
+    LOG(INFO) << "Installing exit stubs in " << thread_name;
   }
+  UniquePtr<Context> context(Context::Create());
+  uintptr_t instrumentation_exit_pc = GetInstrumentationExitPc();
+  InstallStackVisitor visitor(thread, context.get(), instrumentation_exit_pc);
+  visitor.WalkStack(true);
+
+  // Create method enter events for all methods current on the thread's stack.
+  Instrumentation* instrumentation = reinterpret_cast<Instrumentation*>(arg);
+  typedef std::deque<InstrumentationStackFrame>::const_reverse_iterator It;
+  for (It it = thread->GetInstrumentationStack()->rbegin(),
+       end = thread->GetInstrumentationStack()->rend(); it != end; ++it) {
+    mirror::Object* this_object = (*it).this_object_;
+    mirror::AbstractMethod* method = (*it).method_;
+    uint32_t dex_pc = visitor.dex_pcs_.back();
+    visitor.dex_pcs_.pop_back();
+    instrumentation->MethodEnterEvent(thread, this_object, method, dex_pc);
+  }
+  thread->VerifyStack();
 }
 
-static void InstrumentationRestoreStack(Thread* self, void*)
+// Removes the instrumentation exit pc as the return PC for every quick frame.
+static void InstrumentationRestoreStack(Thread* thread, void* arg)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
   struct RestoreStackVisitor : public StackVisitor {
-    RestoreStackVisitor(Thread* self, uintptr_t instrumentation_exit_pc)
-        : StackVisitor(self, NULL), self_(self),
-          instrumentation_exit_pc_(instrumentation_exit_pc) {}
+    RestoreStackVisitor(Thread* thread, uintptr_t instrumentation_exit_pc,
+                        Instrumentation* instrumentation)
+        : StackVisitor(thread, NULL), thread_(thread),
+          instrumentation_exit_pc_(instrumentation_exit_pc),
+          instrumentation_(instrumentation),
+          instrumentation_stack_(thread->GetInstrumentationStack()),
+          frames_removed_(0) {}
 
     virtual bool VisitFrame() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
-      if (self_->IsInstrumentationStackEmpty()) {
+      if (instrumentation_stack_->size() == 0) {
         return false;  // Stop.
       }
       mirror::AbstractMethod* m = GetMethod();
+      if (GetCurrentQuickFrame() == NULL) {
+        if (kVerboseInstrumentation) {
+          LOG(INFO) << "  Ignoring a shadow frame. Frame " << GetFrameId() << " Method=" << PrettyMethod(m);
+        }
+        return true;  // Ignore shadow frames.
+      }
       if (m == NULL) {
+        if (kVerboseInstrumentation) {
+          LOG(INFO) << "  Skipping upcall. Frame " << GetFrameId();
+        }
         return true;  // Ignore upcalls.
       }
-      uintptr_t pc = GetReturnPc();
-      if (pc == instrumentation_exit_pc_) {
-        InstrumentationStackFrame instrumentation_frame = self_->PopInstrumentationStackFrame();
-        SetReturnPc(instrumentation_frame.return_pc_);
-        CHECK(m == instrumentation_frame.method_);
-        CHECK_EQ(GetFrameId(), instrumentation_frame.frame_id_);
-        Runtime* runtime = Runtime::Current();
-        if (runtime->IsMethodTracingActive()) {
-          Trace* trace = runtime->GetInstrumentation()->GetTrace();
-          trace->LogMethodTraceEvent(self_, m, Trace::kMethodTraceExit);
+      typedef std::deque<instrumentation::InstrumentationStackFrame>::const_iterator It; // TODO: C++0x auto
+      bool removed_stub = false;
+      // TODO: make this search more efficient?
+      for (It it = instrumentation_stack_->begin(), end = instrumentation_stack_->end(); it != end;
+          ++it) {
+        InstrumentationStackFrame instrumentation_frame =  *it;
+        if (instrumentation_frame.frame_id_ == GetFrameId()) {
+          if (kVerboseInstrumentation) {
+            LOG(INFO) << "  Removing exit stub in " << DescribeLocation();
+          }
+          CHECK(m == instrumentation_frame.method_) << PrettyMethod(m);
+          SetReturnPc(instrumentation_frame.return_pc_);
+          // Create the method exit events. As the methods didn't really exit the result is 0.
+          instrumentation_->MethodExitEvent(thread_, instrumentation_frame.this_object_, m,
+                                            GetDexPc(), JValue());
+          frames_removed_++;
+          removed_stub = true;
+          break;
+        }
+      }
+      if (!removed_stub) {
+        if (kVerboseInstrumentation) {
+          LOG(INFO) << "  No exit stub in " << DescribeLocation();
+          DescribeStack(thread_);
         }
       }
       return true;  // Continue.
     }
-    Thread* const self_;
+    Thread* const thread_;
     const uintptr_t instrumentation_exit_pc_;
+    Instrumentation* const instrumentation_;
+    std::deque<instrumentation::InstrumentationStackFrame>* const instrumentation_stack_;
+    size_t frames_removed_;
   };
-  uintptr_t instrumentation_exit_pc = GetInstrumentationExitPc();
-  RestoreStackVisitor visitor(self, instrumentation_exit_pc);
-  visitor.WalkStack(true);
-}
-
-Instrumentation::~Instrumentation() {
-  delete trace_;
-}
-
-void Instrumentation::InstallStubs() {
-  Thread* self = Thread::Current();
-  Locks::thread_list_lock_->AssertNotHeld(self);
-  Runtime::Current()->GetClassLinker()->VisitClasses(InstallStubsClassVisitor, NULL);
-  MutexLock mu(self, *Locks::thread_list_lock_);
-  Runtime::Current()->GetThreadList()->ForEach(InstrumentationInstallStack, GetTrace());
-}
-
-void Instrumentation::UninstallStubs() {
-  Thread* self = Thread::Current();
-  Locks::thread_list_lock_->AssertNotHeld(self);
-  Runtime::Current()->GetClassLinker()->VisitClasses(UninstallStubsClassVisitor, NULL);
-  MutexLock mu(self, *Locks::thread_list_lock_);
-  Runtime::Current()->GetThreadList()->ForEach(InstrumentationRestoreStack, NULL);
-}
-
-void Instrumentation::AddSavedCodeToMap(const mirror::AbstractMethod* method, const void* code) {
-  saved_code_map_.Put(method, code);
-}
-
-void Instrumentation::RemoveSavedCodeFromMap(const mirror::AbstractMethod* method) {
-  saved_code_map_.erase(method);
-}
-
-const void* Instrumentation::GetSavedCodeFromMap(const mirror::AbstractMethod* method) {
-  typedef SafeMap<const mirror::AbstractMethod*, const void*>::const_iterator It; // TODO: C++0x auto
-  It it = saved_code_map_.find(method);
-  if (it == saved_code_map_.end()) {
-    return NULL;
-  } else {
-    return it->second;
+  if (kVerboseInstrumentation) {
+    std::string thread_name;
+    thread->GetThreadName(thread_name);
+    LOG(INFO) << "Removing exit stubs in " << thread_name;
+  }
+  std::deque<instrumentation::InstrumentationStackFrame>* stack = thread->GetInstrumentationStack();
+  if (stack->size() > 0) {
+    Instrumentation* instrumentation = reinterpret_cast<Instrumentation*>(arg);
+    uintptr_t instrumentation_exit_pc = GetInstrumentationExitPc();
+    RestoreStackVisitor visitor(thread, instrumentation_exit_pc, instrumentation);
+    visitor.WalkStack(true);
+    CHECK_EQ(visitor.frames_removed_, stack->size());
+    while (stack->size() > 0) {
+      stack->pop_front();
+    }
   }
 }
 
-void Instrumentation::SaveAndUpdateCode(mirror::AbstractMethod* method) {
-#if defined(ART_USE_PORTABLE_COMPILER)
-  UNUSED(method);
-  UNIMPLEMENTED(FATAL);
-#else
-  void* instrumentation_stub = GetInstrumentationEntryPoint();
-  CHECK(GetSavedCodeFromMap(method) == NULL);
-  AddSavedCodeToMap(method, method->GetCode());
-  method->SetCode(instrumentation_stub);
-#endif
+void Instrumentation::AddListener(InstrumentationListener* listener, uint32_t events) {
+  Locks::mutator_lock_->AssertExclusiveHeld(Thread::Current());
+  bool require_entry_exit_stubs = false;
+  bool require_interpreter = false;
+  if ((events & kMethodEntered) != 0) {
+    method_entry_listeners_.push_back(listener);
+    require_entry_exit_stubs = true;
+    have_method_entry_listeners_ = true;
+  }
+  if ((events & kMethodExited) != 0) {
+    method_exit_listeners_.push_back(listener);
+    require_entry_exit_stubs = true;
+    have_method_exit_listeners_ = true;
+  }
+  if ((events & kMethodUnwind) != 0) {
+    method_unwind_listeners_.push_back(listener);
+    have_method_unwind_listeners_ = true;
+  }
+  if ((events & kDexPcMoved) != 0) {
+    dex_pc_listeners_.push_back(listener);
+    require_interpreter = true;
+    have_dex_pc_listeners_ = true;
+  }
+  ConfigureStubs(require_entry_exit_stubs, require_interpreter);
 }
 
-void Instrumentation::ResetSavedCode(mirror::AbstractMethod* method) {
-  CHECK(GetSavedCodeFromMap(method) != NULL);
-  method->SetCode(GetSavedCodeFromMap(method));
-  RemoveSavedCodeFromMap(method);
+void Instrumentation::RemoveListener(InstrumentationListener* listener, uint32_t events) {
+  Locks::mutator_lock_->AssertExclusiveHeld(Thread::Current());
+  bool require_entry_exit_stubs = false;
+  bool require_interpreter = false;
+
+  if ((events & kMethodEntered) != 0) {
+    bool contains = std::find(method_entry_listeners_.begin(), method_entry_listeners_.end(),
+                              listener) != method_entry_listeners_.end();
+    if (contains) {
+      method_entry_listeners_.remove(listener);
+    }
+    have_method_entry_listeners_ = method_entry_listeners_.size() > 0;
+    require_entry_exit_stubs |= have_method_entry_listeners_;
+  }
+  if ((events & kMethodExited) != 0) {
+    bool contains = std::find(method_exit_listeners_.begin(), method_exit_listeners_.end(),
+                              listener) != method_exit_listeners_.end();
+    if (contains) {
+      method_exit_listeners_.remove(listener);
+    }
+    have_method_exit_listeners_ = method_exit_listeners_.size() > 0;
+    require_entry_exit_stubs |= have_method_exit_listeners_;
+  }
+  if ((events & kMethodUnwind) != 0) {
+    method_unwind_listeners_.remove(listener);
+  }
+  if ((events & kDexPcMoved) != 0) {
+    bool contains = std::find(dex_pc_listeners_.begin(), dex_pc_listeners_.end(),
+                              listener) != dex_pc_listeners_.end();
+    if (contains) {
+      dex_pc_listeners_.remove(listener);
+    }
+    have_dex_pc_listeners_ = dex_pc_listeners_.size() > 0;
+    require_interpreter |= have_dex_pc_listeners_;
+  }
+  ConfigureStubs(require_entry_exit_stubs, require_interpreter);
 }
 
-Trace* Instrumentation::GetTrace() const {
-  return trace_;
+void Instrumentation::ConfigureStubs(bool require_entry_exit_stubs, bool require_interpreter) {
+  interpret_only_ = require_interpreter || forced_interpret_only_;
+  // Compute what level of instrumentation is required and compare to current.
+  int desired_level, current_level;
+  if (require_interpreter) {
+    desired_level = 2;
+  } else if (require_entry_exit_stubs) {
+    desired_level = 1;
+  } else {
+    desired_level = 0;
+  }
+  if (interpreter_stubs_installed_) {
+    current_level = 2;
+  } else if (entry_exit_stubs_installed_) {
+    current_level = 1;
+  } else {
+    current_level = 0;
+  }
+  if (desired_level == current_level) {
+    // We're already set.
+    return;
+  }
+  Thread* self = Thread::Current();
+  Runtime* runtime = Runtime::Current();
+  Locks::thread_list_lock_->AssertNotHeld(self);
+  if (desired_level > 0) {
+    if (require_interpreter) {
+      interpreter_stubs_installed_ = true;
+    } else {
+      CHECK(require_entry_exit_stubs);
+      entry_exit_stubs_installed_ = true;
+    }
+    runtime->GetClassLinker()->VisitClasses(InstallStubsClassVisitor, this);
+    instrumentation_stubs_installed_ = true;
+    MutexLock mu(Thread::Current(), *Locks::thread_list_lock_);
+    runtime->GetThreadList()->ForEach(InstrumentationInstallStack, this);
+  } else {
+    interpreter_stubs_installed_ = false;
+    entry_exit_stubs_installed_ = false;
+    runtime->GetClassLinker()->VisitClasses(InstallStubsClassVisitor, this);
+    instrumentation_stubs_installed_ = false;
+    MutexLock mu(self, *Locks::thread_list_lock_);
+    Runtime::Current()->GetThreadList()->ForEach(InstrumentationRestoreStack, this);
+  }
 }
 
-void Instrumentation::SetTrace(Trace* trace) {
-  trace_ = trace;
+void Instrumentation::UpdateMethodsCode(mirror::AbstractMethod* method, const void* code) const {
+  if (LIKELY(!instrumentation_stubs_installed_)) {
+    method->SetCode(code);
+  }
 }
 
-void Instrumentation::RemoveTrace() {
-  delete trace_;
-  trace_ = NULL;
+const void* Instrumentation::GetQuickCodeFor(const mirror::AbstractMethod* method) const {
+  Runtime* runtime = Runtime::Current();
+  if (LIKELY(!instrumentation_stubs_installed_)) {
+    const void* code = method->GetCode();
+    DCHECK(code != NULL);
+    if (LIKELY(code != runtime->GetResolutionStubArray(Runtime::kStaticMethod)->GetData())) {
+      return code;
+    }
+  }
+  return runtime->GetClassLinker()->GetOatCodeFor(method);
 }
 
-uint32_t InstrumentationMethodUnwindFromCode(Thread* self) {
-  Trace* trace = Runtime::Current()->GetInstrumentation()->GetTrace();
-  InstrumentationStackFrame instrumentation_frame = self->PopInstrumentationStackFrame();
+void Instrumentation::MethodEnterEventImpl(Thread* thread, mirror::Object* this_object,
+                                           const mirror::AbstractMethod* method,
+                                           uint32_t dex_pc) const {
+  typedef std::list<InstrumentationListener*>::const_iterator It; // TODO: C++0x auto
+  for (It it = method_entry_listeners_.begin(), end = method_entry_listeners_.end(); it != end;
+      ++it) {
+    (*it)->MethodEntered(thread, this_object, method, dex_pc);
+  }
+}
+
+void Instrumentation::MethodExitEventImpl(Thread* thread, mirror::Object* this_object,
+                                          const mirror::AbstractMethod* method,
+                                          uint32_t dex_pc, const JValue& return_value) const {
+  typedef std::list<InstrumentationListener*>::const_iterator It; // TODO: C++0x auto
+  for (It it = method_exit_listeners_.begin(), end = method_exit_listeners_.end(); it != end;
+      ++it) {
+    (*it)->MethodExited(thread, this_object, method, dex_pc, return_value);
+  }
+}
+
+void Instrumentation::MethodUnwindEvent(Thread* thread, mirror::Object* this_object,
+                                        const mirror::AbstractMethod* method,
+                                        uint32_t dex_pc) const {
+  if (have_method_unwind_listeners_) {
+    typedef std::list<InstrumentationListener*>::const_iterator It; // TODO: C++0x auto
+    for (It it = method_unwind_listeners_.begin(), end = method_unwind_listeners_.end(); it != end;
+        ++it) {
+      (*it)->MethodUnwind(thread, method, dex_pc);
+    }
+  }
+}
+
+void Instrumentation::DexPcMovedEventImpl(Thread* thread, mirror::Object* this_object,
+                                          const mirror::AbstractMethod* method,
+                                          uint32_t dex_pc) const {
+  // TODO: STL copy-on-write collection? The copy below is due to the debug listener having an
+  // action where it can remove itself as a listener and break the iterator. The copy only works
+  // around the problem and in general we may have to move to something like reference counting to
+  // ensure listeners are deleted correctly.
+  std::list<InstrumentationListener*> copy(dex_pc_listeners_);
+  typedef std::list<InstrumentationListener*>::const_iterator It; // TODO: C++0x auto
+  for (It it = copy.begin(), end = copy.end(); it != end; ++it) {
+    (*it)->DexPcMoved(thread, this_object, method, dex_pc);
+  }
+}
+
+void Instrumentation::ExceptionCaughtEvent(Thread* thread, const ThrowLocation& throw_location,
+                                           mirror::AbstractMethod* catch_method,
+                                           uint32_t catch_dex_pc,
+                                           mirror::Throwable* exception_object) {
+  if (have_exception_caught_listeners_) {
+    typedef std::list<InstrumentationListener*>::const_iterator It; // TODO: C++0x auto
+    for (It it = exception_caught_listeners_.begin(), end = exception_caught_listeners_.end();
+        it != end; ++it) {
+      (*it)->ExceptionCaught(thread, throw_location, catch_method, catch_dex_pc, exception_object);
+    }
+  }
+}
+
+static void CheckStackDepth(Thread* self, const InstrumentationStackFrame& instrumentation_frame,
+                            int delta)
+    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+  size_t frame_id = StackVisitor::ComputeNumFrames(self) + delta;
+  if (frame_id != instrumentation_frame.frame_id_) {
+    LOG(ERROR) << "Expected frame_id=" << frame_id << " but found "
+        << instrumentation_frame.frame_id_;
+    StackVisitor::DescribeStack(self);
+    CHECK_EQ(frame_id, instrumentation_frame.frame_id_);
+  }
+}
+
+void Instrumentation::PushInstrumentationStackFrame(Thread* self, mirror::Object* this_object,
+                                                    mirror::AbstractMethod* method,
+                                                    uintptr_t lr) {
+  // We have a callee-save frame meaning this value is guaranteed to never be 0.
+  size_t frame_id = StackVisitor::ComputeNumFrames(self);
+  std::deque<instrumentation::InstrumentationStackFrame>* stack = self->GetInstrumentationStack();
+  if (kVerboseInstrumentation) {
+    LOG(INFO) << "Entering " << PrettyMethod(method) << " from PC " << (void*)lr;
+  }
+  instrumentation::InstrumentationStackFrame instrumentation_frame(this_object, method, lr,
+                                                                   frame_id);
+  stack->push_front(instrumentation_frame);
+
+  MethodEnterEvent(self, this_object, method, 0);
+}
+
+uint64_t Instrumentation::PopInstrumentationStackFrame(Thread* self, uintptr_t* return_pc,
+                                                       uint64_t gpr_result, uint64_t fpr_result) {
+  // Do the pop.
+  std::deque<instrumentation::InstrumentationStackFrame>* stack = self->GetInstrumentationStack();
+  CHECK_GT(stack->size(), 0U);
+  InstrumentationStackFrame instrumentation_frame = stack->front();
+  stack->pop_front();
+
+  // Set return PC and check the sanity of the stack.
+  *return_pc = instrumentation_frame.return_pc_;
+  CheckStackDepth(self, instrumentation_frame, 0);
+
   mirror::AbstractMethod* method = instrumentation_frame.method_;
-  uint32_t lr = instrumentation_frame.return_pc_;
+  char return_shorty = MethodHelper(method).GetShorty()[0];
+  JValue return_value;
+  if (return_shorty == 'V') {
+    return_value.SetJ(0);
+  } else if (return_shorty == 'F' || return_shorty == 'D') {
+    return_value.SetJ(fpr_result);
+  } else {
+    return_value.SetJ(gpr_result);
+  }
+  // TODO: improve the dex pc information here, requires knowledge of current PC as opposed to
+  //       return_pc.
+  uint32_t dex_pc = DexFile::kDexNoIndex;
+  mirror::Object* this_object = instrumentation_frame.this_object_;
+  MethodExitEvent(self, this_object, instrumentation_frame.method_, dex_pc, return_value);
 
-  trace->LogMethodTraceEvent(self, method, Trace::kMethodTraceUnwind);
-
-  return lr;
+  bool deoptimize = false;
+  if (interpreter_stubs_installed_) {
+    // Deoptimize unless we're returning to an upcall.
+    NthCallerVisitor visitor(self, 1, true);
+    visitor.WalkStack(true);
+    deoptimize = visitor.caller != NULL;
+    if (deoptimize && kVerboseInstrumentation) {
+      LOG(INFO) << "Deoptimizing into " << PrettyMethod(visitor.caller);
+    }
+  }
+  if (deoptimize) {
+    if (kVerboseInstrumentation) {
+      LOG(INFO) << "Deoptimizing from " << PrettyMethod(method)
+          << " result is " << std::hex << return_value.GetJ();
+    }
+    self->SetDeoptimizationReturnValue(return_value);
+    return static_cast<uint64_t>(GetDeoptimizationEntryPoint()) |
+        (static_cast<uint64_t>(*return_pc) << 32);
+  } else {
+    if (kVerboseInstrumentation) {
+      LOG(INFO) << "Returning from " << PrettyMethod(method) << " to PC " << (void*)(*return_pc);
+    }
+    return *return_pc;
+  }
 }
 
+void Instrumentation::PopMethodForUnwind(Thread* self, bool is_deoptimization) const {
+  // Do the pop.
+  std::deque<instrumentation::InstrumentationStackFrame>* stack = self->GetInstrumentationStack();
+  CHECK_GT(stack->size(), 0U);
+  InstrumentationStackFrame instrumentation_frame = stack->front();
+  // TODO: bring back CheckStackDepth(self, instrumentation_frame, 2);
+  stack->pop_front();
+
+  mirror::AbstractMethod* method = instrumentation_frame.method_;
+  if (is_deoptimization) {
+    if (kVerboseInstrumentation) {
+      LOG(INFO) << "Popping for deoptimization " << PrettyMethod(method);
+    }
+  } else {
+    if (kVerboseInstrumentation) {
+      LOG(INFO) << "Popping for unwind " << PrettyMethod(method);
+    }
+
+    // Notify listeners of method unwind.
+    // TODO: improve the dex pc information here, requires knowledge of current PC as opposed to
+    //       return_pc.
+    uint32_t dex_pc = DexFile::kDexNoIndex;
+    MethodUnwindEvent(self, instrumentation_frame.this_object_, method, dex_pc);
+  }
+}
+
+std::string InstrumentationStackFrame::Dump() const {
+  std::ostringstream os;
+  os << "Frame " << frame_id_ << " " << PrettyMethod(method_) << ":"
+      << reinterpret_cast<void*>(return_pc_) << " this=" << reinterpret_cast<void*>(this_object_);
+  return os.str();
+}
+
+}  // namespace instrumentation
 }  // namespace art
diff --git a/src/instrumentation.h b/src/instrumentation.h
index fb49bf8..6a4a142 100644
--- a/src/instrumentation.h
+++ b/src/instrumentation.h
@@ -18,61 +18,261 @@
 #define ART_SRC_INSTRUMENTATION_H_
 
 #include "base/macros.h"
-#include "safe_map.h"
+#include "locks.h"
 
 #include <stdint.h>
+#include <list>
 
 namespace art {
-
 namespace mirror {
 class AbstractMethod;
-}
+class Class;
+class Object;
+class Throwable;
+}  // namespace mirror
+union JValue;
 class Thread;
-class Trace;
+class ThrowLocation;
 
-uint32_t InstrumentationMethodUnwindFromCode(Thread* self);
+namespace instrumentation {
 
-struct InstrumentationStackFrame {
-  InstrumentationStackFrame() : method_(NULL), return_pc_(0), frame_id_(0) {}
-  InstrumentationStackFrame(mirror::AbstractMethod* method, uintptr_t return_pc, size_t frame_id)
-      : method_(method), return_pc_(return_pc), frame_id_(frame_id) {
-  }
-  mirror::AbstractMethod* method_;
-  uintptr_t return_pc_;
-  size_t frame_id_;
+const bool kVerboseInstrumentation = false;
+
+// Instrumentation event listener API. Registered listeners will get the appropriate call back for
+// the events they are listening for. The call backs supply the thread, method and dex_pc the event
+// occurred upon. The thread may or may not be Thread::Current().
+struct InstrumentationListener {
+  InstrumentationListener() {}
+  virtual ~InstrumentationListener() {}
+
+  // Call-back for when a method is entered.
+  virtual void MethodEntered(Thread* thread, mirror::Object* this_object,
+                             const mirror::AbstractMethod* method,
+                             uint32_t dex_pc) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) = 0;
+
+  // Call-back for when a method is exited.
+  // TODO: its likely passing the return value would be useful, however, we may need to get and
+  //       parse the shorty to determine what kind of register holds the result.
+  virtual void MethodExited(Thread* thread, mirror::Object* this_object,
+                            const mirror::AbstractMethod* method, uint32_t dex_pc,
+                            const JValue& return_value)
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) = 0;
+
+  // Call-back for when a method is popped due to an exception throw. A method will either cause a
+  // MethodExited call-back or a MethodUnwind call-back when its activation is removed.
+  virtual void MethodUnwind(Thread* thread, const mirror::AbstractMethod* method,
+                            uint32_t dex_pc) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) = 0;
+
+  // Call-back for when the dex pc moves in a method.
+  virtual void DexPcMoved(Thread* thread, mirror::Object* this_object,
+                          const mirror::AbstractMethod* method, uint32_t new_dex_pc)
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) = 0;
+
+  // Call-back when an exception is caught.
+  virtual void ExceptionCaught(Thread* thread, const ThrowLocation& throw_location,
+                               mirror::AbstractMethod* catch_method, uint32_t catch_dex_pc,
+                               mirror::Throwable* exception_object)
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) = 0;
 };
 
+// Instrumentation is a catch-all for when extra information is required from the runtime. The
+// typical use for instrumentation is for profiling and debugging. Instrumentation may add stubs
+// to method entry and exit, it may also force execution to be switched to the interpreter and
+// trigger deoptimization.
 class Instrumentation {
  public:
-  Instrumentation() {}
-  ~Instrumentation();
+  enum InstrumentationEvent {
+    kMethodEntered = 1,
+    kMethodExited = 2,
+    kMethodUnwind = 4,
+    kDexPcMoved = 8,
+    kExceptionCaught = 16
+  };
 
-  // Replaces code of each method with a pointer to a stub for method tracing.
-  void InstallStubs() LOCKS_EXCLUDED(Locks::thread_list_lock_);
+  Instrumentation() :
+      instrumentation_stubs_installed_(false), entry_exit_stubs_installed_(false),
+      interpreter_stubs_installed_(false),
+      interpret_only_(false), forced_interpret_only_(false),
+      have_method_entry_listeners_(false), have_method_exit_listeners_(false),
+      have_method_unwind_listeners_(false), have_dex_pc_listeners_(false),
+      have_exception_caught_listeners_(false) {}
 
-  // Restores original code for each method and fixes the return values of each thread's stack.
-  void UninstallStubs() LOCKS_EXCLUDED(Locks::thread_list_lock_);
+  // Add a listener to be notified of the masked together sent of instrumentation events. This
+  // suspend the runtime to install stubs. You are expected to hold the mutator lock as a proxy
+  // for saying you should have suspended all threads (installing stubs while threads are running
+  // will break).
+  void AddListener(InstrumentationListener* listener, uint32_t events)
+      EXCLUSIVE_LOCKS_REQUIRED(Locks::mutator_lock_)
+      LOCKS_EXCLUDED(Locks::thread_list_lock_, Locks::classlinker_classes_lock_);
 
-  const void* GetSavedCodeFromMap(const mirror::AbstractMethod* method);
-  void SaveAndUpdateCode(mirror::AbstractMethod* method);
-  void ResetSavedCode(mirror::AbstractMethod* method);
+  // Removes a listener possibly removing instrumentation stubs.
+  void RemoveListener(InstrumentationListener* listener, uint32_t events)
+      EXCLUSIVE_LOCKS_REQUIRED(Locks::mutator_lock_)
+      LOCKS_EXCLUDED(Locks::thread_list_lock_, Locks::classlinker_classes_lock_);
 
-  Trace* GetTrace() const;
-  void SetTrace(Trace* trace);
-  void RemoveTrace();
+  // Update the code of a method respecting any installed stubs.
+  void UpdateMethodsCode(mirror::AbstractMethod* method, const void* code) const;
+
+  // Get the quick code for the given method. More efficient than asking the class linker as it
+  // will short-cut to GetCode if instrumentation and static method resolution stubs aren't
+  // installed.
+  const void* GetQuickCodeFor(const mirror::AbstractMethod* method) const
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+  void ForceInterpretOnly() {
+    interpret_only_ = true;
+    forced_interpret_only_ = true;
+  }
+
+  // Called by AbstractMethod::Invoke to determine dispatch mechanism.
+  bool InterpretOnly() const {
+    return interpret_only_;
+  }
+
+  bool ShouldPortableCodeDeoptimize() const {
+    return instrumentation_stubs_installed_;
+  }
+
+  bool AreExitStubsInstalled() const {
+    return instrumentation_stubs_installed_;
+  }
+
+  // Inform listeners that a method has been entered. A dex PC is provided as we may install
+  // listeners into executing code and get method enter events for methods already on the stack.
+  void MethodEnterEvent(Thread* thread, mirror::Object* this_object,
+                        const mirror::AbstractMethod* method, uint32_t dex_pc) const
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+    if (have_method_entry_listeners_) {
+      MethodEnterEventImpl(thread, this_object, method, dex_pc);
+    }
+  }
+
+  // Inform listeners that a method has been exited.
+  void MethodExitEvent(Thread* thread, mirror::Object* this_object,
+                       const mirror::AbstractMethod* method, uint32_t dex_pc,
+                       const JValue& return_value) const
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+    if (have_method_exit_listeners_) {
+      MethodExitEventImpl(thread, this_object, method, dex_pc, return_value);
+    }
+  }
+
+  // Inform listeners that a method has been exited due to an exception.
+  void MethodUnwindEvent(Thread* thread, mirror::Object* this_object,
+                         const mirror::AbstractMethod* method, uint32_t dex_pc) const
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+  // Inform listeners that the dex pc has moved (only supported by the interpreter).
+  void DexPcMovedEvent(Thread* thread, mirror::Object* this_object,
+                       const mirror::AbstractMethod* method, uint32_t dex_pc) const
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+    if (have_dex_pc_listeners_) {
+      DexPcMovedEventImpl(thread, this_object, method, dex_pc);
+    }
+  }
+
+  // Inform listeners that an exception was caught.
+  void ExceptionCaughtEvent(Thread* thread, const ThrowLocation& throw_location,
+                            mirror::AbstractMethod* catch_method, uint32_t catch_dex_pc,
+                            mirror::Throwable* exception_object)
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+  // Called when an instrumented method is entered. The intended link register (lr) is saved so
+  // that returning causes a branch to the method exit stub. Generates method enter events.
+  void PushInstrumentationStackFrame(Thread* self, mirror::Object* this_object,
+                                     mirror::AbstractMethod* method, uintptr_t lr)
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+  // Called when an instrumented method is exited. Removes the pushed instrumentation frame
+  // returning the intended link register. Generates method exit events.
+  uint64_t PopInstrumentationStackFrame(Thread* self, uintptr_t* return_pc, uint64_t gpr_result,
+                                        uint64_t fpr_result)
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+  // Pops an instrumentation frame from the current thread and generate an unwind event.
+  void PopMethodForUnwind(Thread* self, bool is_deoptimization) const
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+  // Call back for configure stubs.
+  bool InstallStubsForClass(mirror::Class* klass) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
  private:
-  void AddSavedCodeToMap(const mirror::AbstractMethod* method, const void* code);
-  void RemoveSavedCodeFromMap(const mirror::AbstractMethod* method);
+  // Does the job of installing or removing instrumentation code within methods.
+  void ConfigureStubs(bool require_entry_exit_stubs, bool require_interpreter)
+      EXCLUSIVE_LOCKS_REQUIRED(Locks::mutator_lock_)
+      LOCKS_EXCLUDED(Locks::thread_list_lock_, Locks::classlinker_classes_lock_);
 
-  // Maps a method to its original code pointer.
-  SafeMap<const mirror::AbstractMethod*, const void*> saved_code_map_;
+  void MethodEnterEventImpl(Thread* thread, mirror::Object* this_object,
+                            const mirror::AbstractMethod* method, uint32_t dex_pc) const
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+  void MethodExitEventImpl(Thread* thread, mirror::Object* this_object,
+                           const mirror::AbstractMethod* method,
+                           uint32_t dex_pc, const JValue& return_value) const
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+  void DexPcMovedEventImpl(Thread* thread, mirror::Object* this_object,
+                           const mirror::AbstractMethod* method, uint32_t dex_pc) const
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
-  Trace* trace_;
+  // Have we hijacked AbstractMethod::code_ so that it calls instrumentation/interpreter code?
+  bool instrumentation_stubs_installed_;
+
+  // Have we hijacked AbstractMethod::code_ to reference the enter/exit stubs?
+  bool entry_exit_stubs_installed_;
+
+  // Have we hijacked AbstractMethod::code_ to reference the enter interpreter stub?
+  bool interpreter_stubs_installed_;
+
+  // Do we need the fidelity of events that we only get from running within the interpreter?
+  bool interpret_only_;
+
+  // Did the runtime request we only run in the interpreter? ie -Xint mode.
+  bool forced_interpret_only_;
+
+  // Do we have any listeners for method entry events? Short-cut to avoid taking the
+  // instrumentation_lock_.
+  bool have_method_entry_listeners_;
+
+  // Do we have any listeners for method exit events? Short-cut to avoid taking the
+  // instrumentation_lock_.
+  bool have_method_exit_listeners_;
+
+  // Do we have any listeners for method unwind events? Short-cut to avoid taking the
+  // instrumentation_lock_.
+  bool have_method_unwind_listeners_;
+
+  // Do we have any listeners for dex move events? Short-cut to avoid taking the
+  // instrumentation_lock_.
+  bool have_dex_pc_listeners_;
+
+  // Do we have any exception caught listeners? Short-cut to avoid taking the instrumentation_lock_.
+  bool have_exception_caught_listeners_;
+
+  // The event listeners, written to with the mutator_lock_ exclusively held.
+  std::list<InstrumentationListener*> method_entry_listeners_ GUARDED_BY(Locks::mutator_lock_);
+  std::list<InstrumentationListener*> method_exit_listeners_ GUARDED_BY(Locks::mutator_lock_);
+  std::list<InstrumentationListener*> method_unwind_listeners_ GUARDED_BY(Locks::mutator_lock_);
+  std::list<InstrumentationListener*> dex_pc_listeners_ GUARDED_BY(Locks::mutator_lock_);
+  std::list<InstrumentationListener*> exception_caught_listeners_ GUARDED_BY(Locks::mutator_lock_);
 
   DISALLOW_COPY_AND_ASSIGN(Instrumentation);
 };
 
+// An element in the instrumentation side stack maintained in art::Thread.
+struct InstrumentationStackFrame {
+  InstrumentationStackFrame(mirror::Object* this_object, mirror::AbstractMethod* method,
+                            uintptr_t return_pc, size_t frame_id)
+      : this_object_(this_object), method_(method), return_pc_(return_pc), frame_id_(frame_id) {
+  }
+
+  std::string Dump() const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+  mirror::Object* this_object_;
+  mirror::AbstractMethod* method_;
+  const uintptr_t return_pc_;
+  const size_t frame_id_;
+};
+
+}  // namespace instrumentation
 }  // namespace art
 
 #endif  // ART_SRC_INSTRUMENTATION_H_
diff --git a/src/interpreter/interpreter.cc b/src/interpreter/interpreter.cc
index 91b381c..b82c632 100644
--- a/src/interpreter/interpreter.cc
+++ b/src/interpreter/interpreter.cc
@@ -21,7 +21,6 @@
 #include "base/logging.h"
 #include "class_linker-inl.h"
 #include "common_throws.h"
-#include "debugger.h"
 #include "dex_file-inl.h"
 #include "dex_instruction.h"
 #include "gc/card_table-inl.h"
@@ -50,10 +49,6 @@
 static const int64_t kMaxLong = std::numeric_limits<int64_t>::max();
 static const int64_t kMinLong = std::numeric_limits<int64_t>::min();
 
-static JDWP::FrameId throw_frame_id_ = 0;
-static AbstractMethod* throw_method_ = NULL;
-static uint32_t throw_dex_pc_ = 0;
-
 static void UnstartedRuntimeInvoke(Thread* self, AbstractMethod* target_method,
                                    Object* receiver, uint32_t* args, JValue* result)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
@@ -441,7 +436,7 @@
     } else {
       obj = shadow_frame.GetVRegReference(dec_insn.vB);
       if (UNLIKELY(obj == NULL)) {
-        ThrowNullPointerExceptionForFieldAccess(f, true);
+        ThrowNullPointerExceptionForFieldAccess(shadow_frame.GetCurrentLocationForThrow(), f, true);
         return;
       }
     }
@@ -488,7 +483,8 @@
     } else {
       obj = shadow_frame.GetVRegReference(dec_insn.vB);
       if (UNLIKELY(obj == NULL)) {
-        ThrowNullPointerExceptionForFieldAccess(f, false);
+        ThrowNullPointerExceptionForFieldAccess(shadow_frame.GetCurrentLocationForThrow(),
+                                                f, false);
         return;
       }
     }
@@ -523,7 +519,7 @@
 static void DoIntDivide(Thread* self, ShadowFrame& shadow_frame, size_t result_reg,
     int32_t dividend, int32_t divisor) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
   if (UNLIKELY(divisor == 0)) {
-    self->ThrowNewException("Ljava/lang/ArithmeticException;", "divide by zero");
+    ThrowArithmeticExceptionDivideByZero(self);
   } else if (UNLIKELY(dividend == kMinInt && divisor == -1)) {
     shadow_frame.SetVReg(result_reg, kMinInt);
   } else {
@@ -534,7 +530,7 @@
 static void DoIntRemainder(Thread* self, ShadowFrame& shadow_frame, size_t result_reg,
     int32_t dividend, int32_t divisor) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
   if (UNLIKELY(divisor == 0)) {
-    self->ThrowNewException("Ljava/lang/ArithmeticException;", "divide by zero");
+    ThrowArithmeticExceptionDivideByZero(self);
   } else if (UNLIKELY(dividend == kMinInt && divisor == -1)) {
     shadow_frame.SetVReg(result_reg, 0);
   } else {
@@ -545,7 +541,7 @@
 static void DoLongDivide(Thread* self, ShadowFrame& shadow_frame, size_t result_reg,
     int64_t dividend, int64_t divisor) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
   if (UNLIKELY(divisor == 0)) {
-    self->ThrowNewException("Ljava/lang/ArithmeticException;", "divide by zero");
+    ThrowArithmeticExceptionDivideByZero(self);
   } else if (UNLIKELY(dividend == kMinLong && divisor == -1)) {
     shadow_frame.SetVRegLong(result_reg, kMinLong);
   } else {
@@ -556,7 +552,7 @@
 static void DoLongRemainder(Thread* self, ShadowFrame& shadow_frame, size_t result_reg,
     int64_t dividend, int64_t divisor) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
   if (UNLIKELY(divisor == 0)) {
-    self->ThrowNewException("Ljava/lang/ArithmeticException;", "divide by zero");
+    ThrowArithmeticExceptionDivideByZero(self);
   } else if (UNLIKELY(dividend == kMinLong && divisor == -1)) {
     shadow_frame.SetVRegLong(result_reg, 0);
   } else {
@@ -567,41 +563,46 @@
 static JValue Execute(Thread* self, MethodHelper& mh, const DexFile::CodeItem* code_item,
                       ShadowFrame& shadow_frame, JValue result_register)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+  if (UNLIKELY(!shadow_frame.HasReferenceArray())) {
+    LOG(FATAL) << "Invalid shadow frame for interpreter use";
+    return JValue();
+  }
+  self->VerifyStack();
+  instrumentation::Instrumentation* instrumentation = Runtime::Current()->GetInstrumentation();
   const uint16_t* insns = code_item->insns_;
   const Instruction* inst = Instruction::At(insns + shadow_frame.GetDexPC());
-  bool entry = (inst->GetDexPc(insns) == 0);
+  if (inst->GetDexPc(insns) == 0) {  // We are entering the method as opposed to deoptimizing..
+    instrumentation->MethodEnterEvent(self, shadow_frame.GetThisObject(), shadow_frame.GetMethod(),
+                                      0);
+  }
   while (true) {
     CheckSuspend(self);
     uint32_t dex_pc = inst->GetDexPc(insns);
     shadow_frame.SetDexPC(dex_pc);
-    if (entry) {
-      Dbg::UpdateDebugger(-1, self);
-    }
-    entry = false;
-    Dbg::UpdateDebugger(dex_pc, self);
+    instrumentation->DexPcMovedEvent(self, shadow_frame.GetThisObject(), shadow_frame.GetMethod(),
+                                     dex_pc);
     DecodedInstruction dec_insn(inst);
     const bool kTracing = false;
     if (kTracing) {
-      LOG(INFO) << PrettyMethod(shadow_frame.GetMethod())
-                << StringPrintf("\n0x%x: %s\nReferences:",
-                                inst->GetDexPc(insns), inst->DumpString(&mh.GetDexFile()).c_str());
+#define TRACE_LOG std::cerr
+      TRACE_LOG << PrettyMethod(shadow_frame.GetMethod())
+                << StringPrintf("\n0x%x: ", inst->GetDexPc(insns))
+                << inst->DumpString(&mh.GetDexFile()) << "\n";
       for (size_t i = 0; i < shadow_frame.NumberOfVRegs(); ++i) {
-        Object* o = shadow_frame.GetVRegReference(i);
-        if (o != NULL) {
-          if (o->GetClass()->IsStringClass() && o->AsString()->GetCharArray() != NULL) {
-            LOG(INFO) << i << ": java.lang.String " << static_cast<void*>(o)
-                  << " \"" << o->AsString()->ToModifiedUtf8() << "\"";
+        uint32_t raw_value = shadow_frame.GetVReg(i);
+        Object* ref_value = shadow_frame.GetVRegReference(i);
+        TRACE_LOG << StringPrintf(" vreg%d=0x%08X", i, raw_value);
+        if (ref_value != NULL) {
+          if (ref_value->GetClass()->IsStringClass() &&
+              ref_value->AsString()->GetCharArray() != NULL) {
+            TRACE_LOG << "/java.lang.String \"" << ref_value->AsString()->ToModifiedUtf8() << "\"";
           } else {
-            LOG(INFO) << i << ": " << PrettyTypeOf(o) << " " << static_cast<void*>(o);
+            TRACE_LOG << "/" << PrettyTypeOf(ref_value);
           }
-        } else {
-          LOG(INFO) << i << ": null";
         }
       }
-      LOG(INFO) << "vregs:";
-      for (size_t i = 0; i < shadow_frame.NumberOfVRegs(); ++i) {
-        LOG(INFO) << StringPrintf("%d: %08x", i, shadow_frame.GetVReg(i));
-      }
+      TRACE_LOG << "\n";
+#undef TRACE_LOG
     }
     const Instruction* next_inst = inst->Next();
     switch (dec_insn.opcode) {
@@ -632,31 +633,42 @@
         shadow_frame.SetVRegReference(dec_insn.vA, result_register.GetL());
         break;
       case Instruction::MOVE_EXCEPTION: {
-        Throwable* exception = self->GetException();
+        Throwable* exception = self->GetException(NULL);
         self->ClearException();
         shadow_frame.SetVRegReference(dec_insn.vA, exception);
         break;
       }
       case Instruction::RETURN_VOID: {
         JValue result;
-        result.SetJ(0);
+        instrumentation->MethodExitEvent(self, shadow_frame.GetThisObject(),
+                                         shadow_frame.GetMethod(), shadow_frame.GetDexPC(),
+                                         result);
         return result;
       }
       case Instruction::RETURN: {
         JValue result;
         result.SetJ(0);
         result.SetI(shadow_frame.GetVReg(dec_insn.vA));
+        instrumentation->MethodExitEvent(self, shadow_frame.GetThisObject(),
+                                         shadow_frame.GetMethod(), shadow_frame.GetDexPC(),
+                                         result);
         return result;
       }
       case Instruction::RETURN_WIDE: {
         JValue result;
         result.SetJ(shadow_frame.GetVRegLong(dec_insn.vA));
+        instrumentation->MethodExitEvent(self, shadow_frame.GetThisObject(),
+                                         shadow_frame.GetMethod(), shadow_frame.GetDexPC(),
+                                         result);
         return result;
       }
       case Instruction::RETURN_OBJECT: {
         JValue result;
         result.SetJ(0);
         result.SetL(shadow_frame.GetVRegReference(dec_insn.vA));
+        instrumentation->MethodExitEvent(self, shadow_frame.GetThisObject(),
+                                         shadow_frame.GetMethod(), shadow_frame.GetDexPC(),
+                                         result);
         return result;
       }
       case Instruction::CONST_4: {
@@ -721,7 +733,7 @@
       case Instruction::MONITOR_ENTER: {
         Object* obj = shadow_frame.GetVRegReference(dec_insn.vA);
         if (UNLIKELY(obj == NULL)) {
-          ThrowNullPointerExceptionFromDexPC(shadow_frame.GetMethod(), inst->GetDexPc(insns));
+          ThrowNullPointerExceptionFromDexPC(shadow_frame.GetCurrentLocationForThrow());
         } else {
           DoMonitorEnter(self, obj);
         }
@@ -730,7 +742,7 @@
       case Instruction::MONITOR_EXIT: {
         Object* obj = shadow_frame.GetVRegReference(dec_insn.vA);
         if (UNLIKELY(obj == NULL)) {
-          ThrowNullPointerExceptionFromDexPC(shadow_frame.GetMethod(), inst->GetDexPc(insns));
+          ThrowNullPointerExceptionFromDexPC(shadow_frame.GetCurrentLocationForThrow());
         } else {
           DoMonitorExit(self, obj);
         }
@@ -743,10 +755,7 @@
         } else {
           Object* obj = shadow_frame.GetVRegReference(dec_insn.vA);
           if (UNLIKELY(obj != NULL && !obj->InstanceOf(c))) {
-            self->ThrowNewExceptionF("Ljava/lang/ClassCastException;",
-                "%s cannot be cast to %s",
-                PrettyDescriptor(obj->GetClass()).c_str(),
-                PrettyDescriptor(c).c_str());
+            ThrowClassCastException(c, obj->GetClass());
           }
         }
         break;
@@ -764,7 +773,7 @@
       case Instruction::ARRAY_LENGTH:  {
         Object* array = shadow_frame.GetVRegReference(dec_insn.vB);
         if (UNLIKELY(array == NULL)) {
-          ThrowNullPointerExceptionFromDexPC(shadow_frame.GetMethod(), inst->GetDexPc(insns));
+          ThrowNullPointerExceptionFromDexPC(shadow_frame.GetCurrentLocationForThrow());
           break;
         }
         shadow_frame.SetVReg(dec_insn.vA, array->AsArray()->GetLength());
@@ -787,7 +796,7 @@
         int32_t length = dec_insn.vA;
         CHECK(is_range || length <= 5);
         if (UNLIKELY(length < 0)) {
-          self->ThrowNewExceptionF("Ljava/lang/NegativeArraySizeException;", "%d", length);
+          ThrowNegativeArraySizeException(length);
           break;
         }
         Class* arrayClass = ResolveVerifyAndClinit(dec_insn.vB, shadow_frame.GetMethod(), self, false, true);
@@ -799,11 +808,11 @@
         Class* componentClass = arrayClass->GetComponentType();
         if (UNLIKELY(componentClass->IsPrimitive() && !componentClass->IsPrimitiveInt())) {
           if (componentClass->IsPrimitiveLong() || componentClass->IsPrimitiveDouble()) {
-            self->ThrowNewExceptionF("Ljava/lang/RuntimeException;",
-                                     "Bad filled array request for type %s",
-                                     PrettyDescriptor(componentClass).c_str());
+            ThrowRuntimeException("Bad filled array request for type %s",
+                                  PrettyDescriptor(componentClass).c_str());
           } else {
-            self->ThrowNewExceptionF("Ljava/lang/InternalError;",
+            self->ThrowNewExceptionF(shadow_frame.GetCurrentLocationForThrow(),
+                                     "Ljava/lang/InternalError;",
                                      "Found type %s; filled-new-array not implemented for anything but \'int\'",
                                      PrettyDescriptor(componentClass).c_str());
           }
@@ -902,9 +911,12 @@
         break;
       }
       case Instruction::THROW: {
-        Object* o = shadow_frame.GetVRegReference(dec_insn.vA);
-        Throwable* t = (o == NULL) ? NULL : o->AsThrowable();
-        self->DeliverException(t);
+        Object* exception = shadow_frame.GetVRegReference(dec_insn.vA);
+        if (exception == NULL) {
+          ThrowNullPointerException(NULL, "throw with null exception");
+        } else {
+          self->SetException(shadow_frame.GetCurrentLocationForThrow(), exception->AsThrowable());
+        }
         break;
       }
       case Instruction::GOTO:
@@ -962,8 +974,7 @@
       case Instruction::FILL_ARRAY_DATA: {
         Object* obj = shadow_frame.GetVRegReference(dec_insn.vA);
         if (UNLIKELY(obj == NULL)) {
-          Thread::Current()->ThrowNewExceptionF("Ljava/lang/NullPointerException;",
-              "null array in FILL_ARRAY_DATA");
+          ThrowNullPointerException(NULL, "null array in FILL_ARRAY_DATA");
           break;
         }
         Array* array = obj->AsArray();
@@ -972,9 +983,10 @@
         const Instruction::ArrayDataPayload* payload =
             reinterpret_cast<const Instruction::ArrayDataPayload*>(insns + dex_pc + dec_insn.vB);
         if (UNLIKELY(static_cast<int32_t>(payload->element_count) > array->GetLength())) {
-          Thread::Current()->ThrowNewExceptionF("Ljava/lang/ArrayIndexOutOfBoundsException;",
-                                                "failed FILL_ARRAY_DATA; length=%d, index=%d",
-                                                array->GetLength(), payload->element_count);
+          self->ThrowNewExceptionF(shadow_frame.GetCurrentLocationForThrow(),
+                                   "Ljava/lang/ArrayIndexOutOfBoundsException;",
+                                   "failed FILL_ARRAY_DATA; length=%d, index=%d",
+                                   array->GetLength(), payload->element_count);
           break;
         }
         uint32_t size_in_bytes = payload->element_count * payload->element_width;
@@ -1068,7 +1080,7 @@
       case Instruction::AGET_BOOLEAN: {
         Object* a = shadow_frame.GetVRegReference(dec_insn.vB);
         if (UNLIKELY(a == NULL)) {
-          ThrowNullPointerExceptionFromDexPC(shadow_frame.GetMethod(), inst->GetDexPc(insns));
+          ThrowNullPointerExceptionFromDexPC(shadow_frame.GetCurrentLocationForThrow());
           break;
         }
         int32_t index = shadow_frame.GetVReg(dec_insn.vC);
@@ -1078,7 +1090,7 @@
       case Instruction::AGET_BYTE: {
         Object* a = shadow_frame.GetVRegReference(dec_insn.vB);
         if (UNLIKELY(a == NULL)) {
-          ThrowNullPointerExceptionFromDexPC(shadow_frame.GetMethod(), inst->GetDexPc(insns));
+          ThrowNullPointerExceptionFromDexPC(shadow_frame.GetCurrentLocationForThrow());
           break;
         }
         int32_t index = shadow_frame.GetVReg(dec_insn.vC);
@@ -1088,7 +1100,7 @@
       case Instruction::AGET_CHAR: {
         Object* a = shadow_frame.GetVRegReference(dec_insn.vB);
         if (UNLIKELY(a == NULL)) {
-          ThrowNullPointerExceptionFromDexPC(shadow_frame.GetMethod(), inst->GetDexPc(insns));
+          ThrowNullPointerExceptionFromDexPC(shadow_frame.GetCurrentLocationForThrow());
           break;
         }
         int32_t index = shadow_frame.GetVReg(dec_insn.vC);
@@ -1098,7 +1110,7 @@
       case Instruction::AGET_SHORT: {
         Object* a = shadow_frame.GetVRegReference(dec_insn.vB);
         if (UNLIKELY(a == NULL)) {
-          ThrowNullPointerExceptionFromDexPC(shadow_frame.GetMethod(), inst->GetDexPc(insns));
+          ThrowNullPointerExceptionFromDexPC(shadow_frame.GetCurrentLocationForThrow());
           break;
         }
         int32_t index = shadow_frame.GetVReg(dec_insn.vC);
@@ -1108,7 +1120,7 @@
       case Instruction::AGET: {
         Object* a = shadow_frame.GetVRegReference(dec_insn.vB);
         if (UNLIKELY(a == NULL)) {
-          ThrowNullPointerExceptionFromDexPC(shadow_frame.GetMethod(), inst->GetDexPc(insns));
+          ThrowNullPointerExceptionFromDexPC(shadow_frame.GetCurrentLocationForThrow());
           break;
         }
         int32_t index = shadow_frame.GetVReg(dec_insn.vC);
@@ -1118,7 +1130,7 @@
       case Instruction::AGET_WIDE:  {
         Object* a = shadow_frame.GetVRegReference(dec_insn.vB);
         if (UNLIKELY(a == NULL)) {
-          ThrowNullPointerExceptionFromDexPC(shadow_frame.GetMethod(), inst->GetDexPc(insns));
+          ThrowNullPointerExceptionFromDexPC(shadow_frame.GetCurrentLocationForThrow());
           break;
         }
         int32_t index = shadow_frame.GetVReg(dec_insn.vC);
@@ -1128,7 +1140,7 @@
       case Instruction::AGET_OBJECT: {
         Object* a = shadow_frame.GetVRegReference(dec_insn.vB);
         if (UNLIKELY(a == NULL)) {
-          ThrowNullPointerExceptionFromDexPC(shadow_frame.GetMethod(), inst->GetDexPc(insns));
+          ThrowNullPointerExceptionFromDexPC(shadow_frame.GetCurrentLocationForThrow());
           break;
         }
         int32_t index = shadow_frame.GetVReg(dec_insn.vC);
@@ -1139,7 +1151,7 @@
         uint8_t val = shadow_frame.GetVReg(dec_insn.vA);
         Object* a = shadow_frame.GetVRegReference(dec_insn.vB);
         if (UNLIKELY(a == NULL)) {
-          ThrowNullPointerExceptionFromDexPC(shadow_frame.GetMethod(), inst->GetDexPc(insns));
+          ThrowNullPointerExceptionFromDexPC(shadow_frame.GetCurrentLocationForThrow());
           break;
         }
         int32_t index = shadow_frame.GetVReg(dec_insn.vC);
@@ -1150,7 +1162,7 @@
         int8_t val = shadow_frame.GetVReg(dec_insn.vA);
         Object* a = shadow_frame.GetVRegReference(dec_insn.vB);
         if (UNLIKELY(a == NULL)) {
-          ThrowNullPointerExceptionFromDexPC(shadow_frame.GetMethod(), inst->GetDexPc(insns));
+          ThrowNullPointerExceptionFromDexPC(shadow_frame.GetCurrentLocationForThrow());
           break;
         }
         int32_t index = shadow_frame.GetVReg(dec_insn.vC);
@@ -1161,7 +1173,7 @@
         uint16_t val = shadow_frame.GetVReg(dec_insn.vA);
         Object* a = shadow_frame.GetVRegReference(dec_insn.vB);
         if (UNLIKELY(a == NULL)) {
-          ThrowNullPointerExceptionFromDexPC(shadow_frame.GetMethod(), inst->GetDexPc(insns));
+          ThrowNullPointerExceptionFromDexPC(shadow_frame.GetCurrentLocationForThrow());
           break;
         }
         int32_t index = shadow_frame.GetVReg(dec_insn.vC);
@@ -1172,7 +1184,7 @@
         int16_t val = shadow_frame.GetVReg(dec_insn.vA);
         Object* a = shadow_frame.GetVRegReference(dec_insn.vB);
         if (UNLIKELY(a == NULL)) {
-          ThrowNullPointerExceptionFromDexPC(shadow_frame.GetMethod(), inst->GetDexPc(insns));
+          ThrowNullPointerExceptionFromDexPC(shadow_frame.GetCurrentLocationForThrow());
           break;
         }
         int32_t index = shadow_frame.GetVReg(dec_insn.vC);
@@ -1183,7 +1195,7 @@
         int32_t val = shadow_frame.GetVReg(dec_insn.vA);
         Object* a = shadow_frame.GetVRegReference(dec_insn.vB);
         if (UNLIKELY(a == NULL)) {
-          ThrowNullPointerExceptionFromDexPC(shadow_frame.GetMethod(), inst->GetDexPc(insns));
+          ThrowNullPointerExceptionFromDexPC(shadow_frame.GetCurrentLocationForThrow());
           break;
         }
         int32_t index = shadow_frame.GetVReg(dec_insn.vC);
@@ -1194,7 +1206,7 @@
         int64_t val = shadow_frame.GetVRegLong(dec_insn.vA);
         Object* a = shadow_frame.GetVRegReference(dec_insn.vB);
         if (UNLIKELY(a == NULL)) {
-          ThrowNullPointerExceptionFromDexPC(shadow_frame.GetMethod(), inst->GetDexPc(insns));
+          ThrowNullPointerExceptionFromDexPC(shadow_frame.GetCurrentLocationForThrow());
           break;
         }
         int32_t index = shadow_frame.GetVReg(dec_insn.vC);
@@ -1205,7 +1217,7 @@
         Object* val = shadow_frame.GetVRegReference(dec_insn.vA);
         Object* a = shadow_frame.GetVRegReference(dec_insn.vB);
         if (UNLIKELY(a == NULL)) {
-          ThrowNullPointerExceptionFromDexPC(shadow_frame.GetMethod(), inst->GetDexPc(insns));
+          ThrowNullPointerExceptionFromDexPC(shadow_frame.GetCurrentLocationForThrow());
           break;
         }
         int32_t index = shadow_frame.GetVReg(dec_insn.vC);
@@ -1777,22 +1789,21 @@
         break;
     }
     if (UNLIKELY(self->IsExceptionPending())) {
-      if (throw_frame_id_ == 0) {
-        throw_method_ = shadow_frame.GetMethod();
-        throw_dex_pc_ = dex_pc;
-      }
-      throw_frame_id_++;
+      self->VerifyStack();
+      ThrowLocation throw_location;
+      mirror::Throwable* exception = self->GetException(&throw_location);
       uint32_t found_dex_pc =
-          shadow_frame.GetMethod()->FindCatchBlock(self->GetException()->GetClass(),
-                                                   inst->GetDexPc(insns));
+          shadow_frame.GetMethod()->FindCatchBlock(exception->GetClass(), inst->GetDexPc(insns));
       if (found_dex_pc == DexFile::kDexNoIndex) {
         JValue result;
         result.SetJ(0);
+        instrumentation->MethodUnwindEvent(self, shadow_frame.GetThisObject(),
+                                           shadow_frame.GetMethod(), shadow_frame.GetDexPC());
         return result;  // Handler in caller.
       } else {
-        Dbg::PostException(self, throw_frame_id_, throw_method_, throw_dex_pc_,
-                           shadow_frame.GetMethod(), found_dex_pc, self->GetException());
-        throw_frame_id_ = 0;
+        Runtime::Current()->GetInstrumentation()->ExceptionCaughtEvent(self, throw_location,
+                                                                       shadow_frame.GetMethod(),
+                                                                       found_dex_pc, exception);
         next_inst = Instruction::At(insns + found_dex_pc);
       }
     }
@@ -1816,8 +1827,9 @@
     num_regs =  code_item->registers_size_;
     num_ins = code_item->ins_size_;
   } else if (method->IsAbstract()) {
-    self->ThrowNewExceptionF("Ljava/lang/AbstractMethodError;", "abstract method \"%s\"",
-                             PrettyMethod(method).c_str());
+    ThrowLocation throw_location = self->GetCurrentLocationForThrow();
+    self->ThrowNewExceptionF(throw_location, "Ljava/lang/AbstractMethodError;",
+                             "abstract method \"%s\"", PrettyMethod(method).c_str());
     return;
   } else {
     DCHECK(method->IsNative());
@@ -1884,23 +1896,18 @@
   self->PopShadowFrame();
 }
 
-JValue EnterInterpreterFromDeoptimize(Thread* self, ShadowFrame& shadow_frame, JValue ret_val)
-    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
-  MethodHelper mh(shadow_frame.GetMethod());
-  const DexFile::CodeItem* code_item = mh.GetCodeItem();
-  return Execute(self, mh, code_item, shadow_frame, ret_val);
-}
-
-void EnterInterpreterFromLLVM(Thread* self, ShadowFrame* shadow_frame, JValue* ret_val)
+void EnterInterpreterFromDeoptimize(Thread* self, ShadowFrame* shadow_frame, JValue* ret_val)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
   JValue value;
-  MethodHelper mh(shadow_frame->GetMethod());
-  const DexFile::CodeItem* code_item = mh.GetCodeItem();
+  value.SetJ(ret_val->GetJ());  // Set value to last known result in case the shadow frame chain is empty.
+  MethodHelper mh;
   while (shadow_frame != NULL) {
+    self->SetTopOfShadowStack(shadow_frame);
+    mh.ChangeMethod(shadow_frame->GetMethod());
+    const DexFile::CodeItem* code_item = mh.GetCodeItem();
     value = Execute(self, mh, code_item, *shadow_frame, value);
     ShadowFrame* old_frame = shadow_frame;
     shadow_frame = shadow_frame->GetLink();
-    mh.ChangeMethod(shadow_frame->GetMethod());
     delete old_frame;
   }
   ret_val->SetJ(value.GetJ());
diff --git a/src/interpreter/interpreter.h b/src/interpreter/interpreter.h
index 556b044..cf47b68 100644
--- a/src/interpreter/interpreter.h
+++ b/src/interpreter/interpreter.h
@@ -33,15 +33,13 @@
 
 namespace interpreter {
 
+// Called by AbstractMethod::Invoke, shadow frames arguments are taken from the args array.
 extern void EnterInterpreterFromInvoke(Thread* self, mirror::AbstractMethod* method,
                                        mirror::Object* receiver, uint32_t* args, JValue* result)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
-extern JValue EnterInterpreterFromDeoptimize(Thread* self, ShadowFrame& shadow_frame,
-                                             JValue ret_val)
-    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
-
-void EnterInterpreterFromLLVM(Thread* self, ShadowFrame* shadow_frame, JValue* result)
+extern void EnterInterpreterFromDeoptimize(Thread* self, ShadowFrame* shadow_frame,
+                                           JValue* ret_val)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
 extern JValue EnterInterpreterFromStub(Thread* self, MethodHelper& mh,
diff --git a/src/invoke_arg_array_builder.h b/src/invoke_arg_array_builder.h
index aca1091..a6e99a5 100644
--- a/src/invoke_arg_array_builder.h
+++ b/src/invoke_arg_array_builder.h
@@ -43,13 +43,24 @@
  public:
   explicit ArgArray(const char* shorty, uint32_t shorty_len)
       : shorty_(shorty), shorty_len_(shorty_len), num_bytes_(0) {
-    // TODO: This code is conservative. The multiply by 2 is to handle the case where all args are
-    // doubles or longs. We could scan the shorty to use the arg array more often.
-    if (shorty_len * 2 <= kSmallArgArraySize) {
+    size_t num_slots = shorty_len + 1;  // +1 in case of receiver.
+    if (LIKELY((num_slots * 2) < kSmallArgArraySize)) {
+      // We can trivially use the small arg array.
       arg_array_ = small_arg_array_;
     } else {
-      large_arg_array_.reset(new uint32_t[shorty_len_ * 2]);
-      arg_array_ = large_arg_array_.get();
+      // Analyze shorty to see if we need the large arg array.
+      for (size_t i = 1; i < shorty_len; ++i) {
+        char c = shorty[i];
+        if (c == 'J' || c == 'D') {
+          num_slots++;
+        }
+      }
+      if (num_slots <= kSmallArgArraySize) {
+        arg_array_ = small_arg_array_;
+      } else {
+        large_arg_array_.reset(new uint32_t[num_slots]);
+        arg_array_ = large_arg_array_.get();
+      }
     }
   }
 
diff --git a/src/jdwp/jdwp_event.cc b/src/jdwp/jdwp_event.cc
index eb385fc..5b65aa4 100644
--- a/src/jdwp/jdwp_event.cc
+++ b/src/jdwp/jdwp_event.cc
@@ -1069,21 +1069,31 @@
   // Try to avoid blocking GC during a send, but only safe when not using mutexes at a lower-level
   // than mutator for lock ordering reasons.
   Thread* self = Thread::Current();
-  bool safe_to_release_mutator_lock_over_send;
-  for (size_t i=0; i < kMutatorLock; ++i) {
-    if (self->GetHeldMutex(static_cast<LockLevel>(i)) != NULL) {
-      safe_to_release_mutator_lock_over_send = false;
-      break;
+  bool safe_to_release_mutator_lock_over_send = !Locks::mutator_lock_->IsExclusiveHeld(self);
+  if (safe_to_release_mutator_lock_over_send) {
+    for (size_t i=0; i < kMutatorLock; ++i) {
+      if (self->GetHeldMutex(static_cast<LockLevel>(i)) != NULL) {
+        safe_to_release_mutator_lock_over_send = false;
+        break;
+      }
     }
   }
+  bool success;
   if (safe_to_release_mutator_lock_over_send) {
     // Change state to waiting to allow GC, ... while we're sending.
     self->TransitionFromRunnableToSuspended(kWaitingForDebuggerSend);
-    (*transport_->sendBufferedRequest)(this, wrapiov, iov_count + 1);
+    success = (*transport_->sendBufferedRequest)(this, wrapiov, iov_count + 1);
     self->TransitionFromSuspendedToRunnable();
   } else {
     // Send and possibly block GC...
-    (*transport_->sendBufferedRequest)(this, wrapiov, iov_count + 1);
+    success = (*transport_->sendBufferedRequest)(this, wrapiov, iov_count + 1);
+  }
+  if (!success) {
+    LOG(INFO) << StringPrintf("JDWP send of type %c%c%c%c failed.",
+                              static_cast<uint8_t>(type >> 24),
+                              static_cast<uint8_t>(type >> 16),
+                              static_cast<uint8_t>(type >> 8),
+                              static_cast<uint8_t>(type));
   }
 }
 
diff --git a/src/jdwp/jdwp_main.cc b/src/jdwp/jdwp_main.cc
index 4e738ff..1f121f8 100644
--- a/src/jdwp/jdwp_main.cc
+++ b/src/jdwp/jdwp_main.cc
@@ -334,6 +334,7 @@
 
   /* set the thread state to kWaitingInMainDebuggerLoop so GCs don't wait for us */
   CHECK_EQ(thread_->GetState(), kNative);
+  Locks::mutator_lock_->AssertNotHeld(thread_);
   thread_->SetState(kWaitingInMainDebuggerLoop);
 
   /*
@@ -421,10 +422,9 @@
 
       // Release session state, e.g. remove breakpoint instructions.
       ResetState();
-
-      // Tell the rest of the runtime that the debugger is no longer around.
-      Dbg::Disconnected();
     }
+    // Tell the rest of the runtime that the debugger is no longer around.
+    Dbg::Disconnected();
 
     /* if we had threads suspended, resume them now */
     Dbg::UndoDebuggerSuspensions();
diff --git a/src/jni_internal.cc b/src/jni_internal.cc
index 6df03e9..a6c9fa1 100644
--- a/src/jni_internal.cc
+++ b/src/jni_internal.cc
@@ -112,7 +112,7 @@
       CHECK(self->IsExceptionPending());
       LOG(ERROR) << "Internal error: unresolvable type for argument type in JNI invoke: "
           << mh.GetTypeDescriptorFromTypeIdx(type_idx) << "\n"
-          << self->GetException()->Dump();
+          << self->GetException(NULL)->Dump();
       self->ClearException();
       ++error_count;
     } else if (!param_type->IsPrimitive()) {
@@ -214,8 +214,10 @@
 static void ThrowNoSuchMethodError(ScopedObjectAccess& soa, Class* c,
                                    const char* name, const char* sig, const char* kind)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
-  soa.Self()->ThrowNewExceptionF("Ljava/lang/NoSuchMethodError;",
-      "no %s method \"%s.%s%s\"", kind, ClassHelper(c).GetDescriptor(), name, sig);
+  ThrowLocation throw_location = soa.Self()->GetCurrentLocationForThrow();
+  soa.Self()->ThrowNewExceptionF(throw_location, "Ljava/lang/NoSuchMethodError;",
+                                 "no %s method \"%s.%s%s\"",
+                                 kind, ClassHelper(c).GetDescriptor(), name, sig);
 }
 
 static jmethodID FindMethodID(ScopedObjectAccess& soa, jclass jni_class,
@@ -248,7 +250,7 @@
 
 static ClassLoader* GetClassLoader(const ScopedObjectAccess& soa)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
-  AbstractMethod* method = soa.Self()->GetCurrentMethod();
+  AbstractMethod* method = soa.Self()->GetCurrentMethod(NULL);
   if (method == NULL ||
       method == soa.DecodeMethod(WellKnownClasses::java_lang_Runtime_nativeLoad)) {
     return soa.Self()->GetClassLoaderOverride();
@@ -276,10 +278,14 @@
   if (field_type == NULL) {
     // Failed to find type from the signature of the field.
     DCHECK(soa.Self()->IsExceptionPending());
+    ThrowLocation throw_location;
+    SirtRef<mirror::Throwable> cause(soa.Self(), soa.Self()->GetException(&throw_location));
     soa.Self()->ClearException();
-    soa.Self()->ThrowNewExceptionF("Ljava/lang/NoSuchFieldError;",
-        "no type \"%s\" found and so no field \"%s\" could be found in class "
-        "\"%s\" or its superclasses", sig, name, ClassHelper(c).GetDescriptor());
+    soa.Self()->ThrowNewExceptionF(throw_location, "Ljava/lang/NoSuchFieldError;",
+                                   "no type \"%s\" found and so no field \"%s\" could be found in class "
+                                   "\"%s\" or its superclasses", sig, name,
+                                   ClassHelper(c).GetDescriptor());
+    soa.Self()->GetException(NULL)->SetCause(cause.get());
     return NULL;
   }
   if (is_static) {
@@ -288,9 +294,10 @@
     field = c->FindInstanceField(name, ClassHelper(field_type).GetDescriptor());
   }
   if (field == NULL) {
-    soa.Self()->ThrowNewExceptionF("Ljava/lang/NoSuchFieldError;",
-        "no \"%s\" field \"%s\" in class \"%s\" or its superclasses", sig,
-        name, ClassHelper(c).GetDescriptor());
+    ThrowLocation throw_location = soa.Self()->GetCurrentLocationForThrow();
+    soa.Self()->ThrowNewExceptionF(throw_location, "Ljava/lang/NoSuchFieldError;",
+                                   "no \"%s\" field \"%s\" in class \"%s\" or its superclasses",
+                                   sig, name, ClassHelper(c).GetDescriptor());
     return NULL;
   }
   return soa.EncodeField(field);
@@ -314,16 +321,19 @@
                         jsize length, const char* identifier)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
   std::string type(PrettyTypeOf(array));
-  soa.Self()->ThrowNewExceptionF("Ljava/lang/ArrayIndexOutOfBoundsException;",
-      "%s offset=%d length=%d %s.length=%d",
-      type.c_str(), start, length, identifier, array->GetLength());
+  ThrowLocation throw_location = soa.Self()->GetCurrentLocationForThrow();
+  soa.Self()->ThrowNewExceptionF(throw_location, "Ljava/lang/ArrayIndexOutOfBoundsException;",
+                                 "%s offset=%d length=%d %s.length=%d",
+                                 type.c_str(), start, length, identifier, array->GetLength());
 }
 
 static void ThrowSIOOBE(ScopedObjectAccess& soa, jsize start, jsize length,
                         jsize array_length)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
-  soa.Self()->ThrowNewExceptionF("Ljava/lang/StringIndexOutOfBoundsException;",
-      "offset=%d length=%d string.length()=%d", start, length, array_length);
+  ThrowLocation throw_location = soa.Self()->GetCurrentLocationForThrow();
+  soa.Self()->ThrowNewExceptionF(throw_location, "Ljava/lang/StringIndexOutOfBoundsException;",
+                                 "offset=%d length=%d string.length()=%d", start, length,
+                                 array_length);
 }
 
 int ThrowNewException(JNIEnv* env, jclass exception_class, const char* msg, jobject cause)
@@ -362,10 +372,9 @@
   if (exception.get() == NULL) {
     return JNI_ERR;
   }
-
   ScopedObjectAccess soa(env);
-  soa.Self()->SetException(soa.Decode<Throwable*>(exception.get()));
-
+  ThrowLocation throw_location = soa.Self()->GetCurrentLocationForThrow();
+  soa.Self()->SetException(throw_location, soa.Decode<Throwable*>(exception.get()));
   return JNI_OK;
 }
 
@@ -678,7 +687,8 @@
     if (exception == NULL) {
       return JNI_ERR;
     }
-    soa.Self()->SetException(exception);
+    ThrowLocation throw_location = soa.Self()->GetCurrentLocationForThrow();
+    soa.Self()->SetException(throw_location, exception);
     return JNI_OK;
   }
 
@@ -697,31 +707,42 @@
   static void ExceptionDescribe(JNIEnv* env) {
     ScopedObjectAccess soa(env);
 
-    Thread* self = soa.Self();
-    Throwable* original_exception = self->GetException();
-    self->ClearException();
-
-    ScopedLocalRef<jthrowable> exception(env, soa.AddLocalReference<jthrowable>(original_exception));
+    SirtRef<mirror::Object> old_throw_this_object(soa.Self(), NULL);
+    SirtRef<mirror::AbstractMethod> old_throw_method(soa.Self(), NULL);
+    SirtRef<mirror::Throwable> old_exception(soa.Self(), NULL);
+    uint32_t old_throw_dex_pc;
+    {
+      ThrowLocation old_throw_location;
+      mirror::Throwable* old_exception_obj = soa.Self()->GetException(&old_throw_location);
+      old_throw_this_object.reset(old_throw_location.GetThis());
+      old_throw_method.reset(old_throw_location.GetMethod());
+      old_exception.reset(old_exception_obj);
+      old_throw_dex_pc = old_throw_location.GetDexPc();
+      soa.Self()->ClearException();
+    }
+    ScopedLocalRef<jthrowable> exception(env, soa.AddLocalReference<jthrowable>(old_exception.get()));
     ScopedLocalRef<jclass> exception_class(env, env->GetObjectClass(exception.get()));
     jmethodID mid = env->GetMethodID(exception_class.get(), "printStackTrace", "()V");
     if (mid == NULL) {
       LOG(WARNING) << "JNI WARNING: no printStackTrace()V in "
-                   << PrettyTypeOf(original_exception);
+                   << PrettyTypeOf(old_exception.get());
     } else {
       env->CallVoidMethod(exception.get(), mid);
-      if (self->IsExceptionPending()) {
-        LOG(WARNING) << "JNI WARNING: " << PrettyTypeOf(self->GetException())
+      if (soa.Self()->IsExceptionPending()) {
+        LOG(WARNING) << "JNI WARNING: " << PrettyTypeOf(soa.Self()->GetException(NULL))
                      << " thrown while calling printStackTrace";
-        self->ClearException();
+        soa.Self()->ClearException();
       }
     }
+    ThrowLocation gc_safe_throw_location(old_throw_this_object.get(), old_throw_method.get(),
+                                         old_throw_dex_pc);
 
-    self->SetException(original_exception);
+    soa.Self()->SetException(gc_safe_throw_location, old_exception.get());
   }
 
   static jthrowable ExceptionOccurred(JNIEnv* env) {
     ScopedObjectAccess soa(env);
-    Object* exception = soa.Self()->GetException();
+    Object* exception = soa.Self()->GetException(NULL);
     return soa.AddLocalReference<jthrowable>(exception);
   }
 
@@ -2134,10 +2155,10 @@
 
   static jobject NewDirectByteBuffer(JNIEnv* env, void* address, jlong capacity) {
     if (capacity < 0) {
-      JniAbortF("NewDirectByteBuffer", "negative buffer capacity: %d", capacity);
+      JniAbortF("NewDirectByteBuffer", "negative buffer capacity: %lld", capacity);
     }
     if (address == NULL && capacity != 0) {
-      JniAbortF("NewDirectByteBuffer", "non-zero capacity for NULL pointer: %d", capacity);
+      JniAbortF("NewDirectByteBuffer", "non-zero capacity for NULL pointer: %lld", capacity);
     }
 
     // At the moment, the Java side is limited to 32 bits.
@@ -2676,7 +2697,7 @@
       force_copy(false), // TODO: add a way to enable this
       trace(options->jni_trace_),
       work_around_app_jni_bugs(false),
-      pins_lock("JNI pin table lock"),
+      pins_lock("JNI pin table lock", kPinTableLock),
       pin_table("pin table", kPinTableInitial, kPinTableMax),
       globals_lock("JNI global reference table lock"),
       globals(gGlobalsInitial, gGlobalsMax, kGlobal),
@@ -2889,9 +2910,10 @@
     MutexLock mu(self, libraries_lock);
     native_method = libraries->FindNativeMethod(m, detail);
   }
-  // throwing can cause libraries_lock to be reacquired
+  // Throwing can cause libraries_lock to be reacquired.
   if (native_method == NULL) {
-    self->ThrowNewException("Ljava/lang/UnsatisfiedLinkError;", detail.c_str());
+    ThrowLocation throw_location = self->GetCurrentLocationForThrow();
+    self->ThrowNewException(throw_location, "Ljava/lang/UnsatisfiedLinkError;", detail.c_str());
   }
   return native_method;
 }
diff --git a/src/jni_internal.h b/src/jni_internal.h
index 9c067de..131032a 100644
--- a/src/jni_internal.h
+++ b/src/jni_internal.h
@@ -49,7 +49,8 @@
 class Thread;
 
 void SetJniGlobalsMax(size_t max);
-void JniAbortF(const char* jni_function_name, const char* fmt, ...);
+void JniAbortF(const char* jni_function_name, const char* fmt, ...)
+    __attribute__((__format__(__printf__, 2, 3)));
 void* FindNativeMethod(Thread* thread);
 void RegisterNativeMethods(JNIEnv* env, const char* jni_class_name, const JNINativeMethod* methods,
                            size_t method_count);
diff --git a/src/jvalue.h b/src/jvalue.h
index fa85937..66cd93e 100644
--- a/src/jvalue.h
+++ b/src/jvalue.h
@@ -19,6 +19,8 @@
 
 #include "base/macros.h"
 
+#include <stdint.h>
+
 namespace art {
 namespace mirror {
 class Object;
diff --git a/src/locks.cc b/src/locks.cc
index 27b9d4b..eb0620c 100644
--- a/src/locks.cc
+++ b/src/locks.cc
@@ -29,6 +29,7 @@
 Mutex* Locks::runtime_shutdown_lock_ = NULL;
 Mutex* Locks::thread_list_lock_ = NULL;
 Mutex* Locks::thread_suspend_count_lock_ = NULL;
+Mutex* Locks::trace_lock_ = NULL;
 Mutex* Locks::unexpected_signal_lock_ = NULL;
 
 void Locks::Init() {
@@ -42,6 +43,7 @@
     DCHECK(mutator_lock_ != NULL);
     DCHECK(thread_list_lock_ != NULL);
     DCHECK(thread_suspend_count_lock_ != NULL);
+    DCHECK(trace_lock_ != NULL);
     DCHECK(unexpected_signal_lock_ != NULL);
   } else {
     logging_lock_ = new Mutex("logging lock", kLoggingLock, true);
@@ -61,6 +63,8 @@
     thread_list_lock_ = new Mutex("thread list lock", kThreadListLock);
     DCHECK(thread_suspend_count_lock_ == NULL);
     thread_suspend_count_lock_ = new Mutex("thread suspend count lock", kThreadSuspendCountLock);
+    DCHECK(trace_lock_ == NULL);
+    trace_lock_ = new Mutex("trace lock", kTraceLock);
     DCHECK(unexpected_signal_lock_ == NULL);
     unexpected_signal_lock_ = new Mutex("unexpected signal lock", kUnexpectedSignalLock, true);
   }
diff --git a/src/locks.h b/src/locks.h
index c0f6ae5..568f950 100644
--- a/src/locks.h
+++ b/src/locks.h
@@ -37,17 +37,20 @@
   kThreadSuspendCountLock,
   kAbortLock,
   kDefaultMutexLevel,
+  kJdwpSerialLock,
   kAllocSpaceLock,
+  kMarkSweepLargeObjectLock,
+  kPinTableLock,
   kLoadLibraryLock,
   kClassLinkerClassesLock,
   kBreakpointLock,
+  kJdwpObjectRegistryLock,
   kThreadListLock,
   kBreakpointInvokeLock,
-  kJdwpObjectRegistryLock,
+  kTraceLock,
   kJdwpEventListLock,
   kJdwpAttachLock,
   kJdwpStartLock,
-  kJdwpSerialLock,
   kRuntimeShutdownLock,
   kHeapBitmapLock,
   kMonitorLock,
@@ -136,8 +139,11 @@
   // Guards breakpoints and single-stepping.
   static Mutex* breakpoint_lock_ ACQUIRED_AFTER(thread_list_lock_);
 
+  // Guards trace requests.
+  static Mutex* trace_lock_ ACQUIRED_AFTER(breakpoint_lock_);
+
   // Guards lists of classes within the class linker.
-  static Mutex* classlinker_classes_lock_ ACQUIRED_AFTER(breakpoint_lock_);
+  static Mutex* classlinker_classes_lock_ ACQUIRED_AFTER(trace_lock_);
 
   // When declaring any Mutex add DEFAULT_MUTEX_ACQUIRED_AFTER to use annotalysis to check the code
   // doesn't try to hold a higher level Mutex.
diff --git a/src/mirror/abstract_method-inl.h b/src/mirror/abstract_method-inl.h
index 2049748..fd02474 100644
--- a/src/mirror/abstract_method-inl.h
+++ b/src/mirror/abstract_method-inl.h
@@ -20,6 +20,7 @@
 #include "abstract_method.h"
 
 #include "dex_file.h"
+#include "oat/runtime/oat_support_entrypoints.h"
 #include "object_array.h"
 #include "runtime.h"
 
@@ -113,6 +114,9 @@
   if (IsNative() || IsRuntimeMethod() || IsProxyMethod()) {
     return;
   }
+  if (GetCode() == GetInterpreterEntryPoint()) {
+    return;
+  }
   Runtime* runtime = Runtime::Current();
   if (GetCode() == runtime->GetResolutionStubArray(Runtime::kStaticMethod)->GetData()) {
       return;
diff --git a/src/mirror/abstract_method.cc b/src/mirror/abstract_method.cc
index f74814c..3ab3a93 100644
--- a/src/mirror/abstract_method.cc
+++ b/src/mirror/abstract_method.cc
@@ -151,23 +151,9 @@
   return result;
 }
 
-static const void* GetOatCode(const AbstractMethod* m)
-    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
-  Runtime* runtime = Runtime::Current();
-  const void* code = m->GetCode();
-  // Peel off any method tracing trampoline.
-  if (runtime->IsMethodTracingActive() && runtime->GetInstrumentation()->GetSavedCodeFromMap(m) != NULL) {
-    code = runtime->GetInstrumentation()->GetSavedCodeFromMap(m);
-  }
-  // Peel off any resolution stub.
-  if (code == runtime->GetResolutionStubArray(Runtime::kStaticMethod)->GetData()) {
-    code = runtime->GetClassLinker()->GetOatCodeFor(m);
-  }
-  return code;
-}
-
 uintptr_t AbstractMethod::NativePcOffset(const uintptr_t pc) const {
-  return pc - reinterpret_cast<uintptr_t>(GetOatCode(this));
+  const void* code = Runtime::Current()->GetInstrumentation()->GetQuickCodeFor(this);
+  return pc - reinterpret_cast<uintptr_t>(code);
 }
 
 // Find the lowest-address native safepoint pc for a given dex pc
@@ -181,7 +167,8 @@
   size_t mapping_table_length = GetPcToDexMappingTableLength();
   for (size_t i = 0; i < mapping_table_length; i += 2) {
     if (mapping_table[i + 1] == dex_pc) {
-      return mapping_table[i] + reinterpret_cast<uintptr_t>(GetOatCode(this));
+      const void* code = Runtime::Current()->GetInstrumentation()->GetQuickCodeFor(this);
+      return mapping_table[i] + reinterpret_cast<uintptr_t>(code);
     }
   }
   LOG(FATAL) << "Failed to find native offset for dex pc 0x" << std::hex << dex_pc
@@ -201,14 +188,16 @@
     return DexFile::kDexNoIndex;   // Special no mapping case
   }
   size_t mapping_table_length = GetPcToDexMappingTableLength();
-  uint32_t sought_offset = pc - reinterpret_cast<uintptr_t>(GetOatCode(this));
+  const void* code = Runtime::Current()->GetInstrumentation()->GetQuickCodeFor(this);
+  uint32_t sought_offset = pc - reinterpret_cast<uintptr_t>(code);
   for (size_t i = 0; i < mapping_table_length; i += 2) {
     if (mapping_table[i] == sought_offset) {
       return mapping_table[i + 1];
     }
   }
-  LOG(ERROR) << "Failed to find Dex offset for PC offset " << reinterpret_cast<void*>(sought_offset)
-             << "(PC " << reinterpret_cast<void*>(pc) << ") in " << PrettyMethod(this);
+  LOG(FATAL) << "Failed to find Dex offset for PC offset " << reinterpret_cast<void*>(sought_offset)
+             << "(PC " << reinterpret_cast<void*>(pc) << ", code=" << code
+             << ") in " << PrettyMethod(this);
   return DexFile::kDexNoIndex;
 #else
   // Compiler LLVM doesn't use the machine pc, we just use dex pc instead.
@@ -227,7 +216,8 @@
     uint32_t map_offset = mapping_table[i];
     uint32_t map_dex_offset = mapping_table[i + 1];
     if (map_dex_offset == dex_pc) {
-      return reinterpret_cast<uintptr_t>(GetOatCode(this)) + map_offset;
+      const void* code = Runtime::Current()->GetInstrumentation()->GetQuickCodeFor(this);
+      return reinterpret_cast<uintptr_t>(code) + map_offset;
     }
   }
   LOG(FATAL) << "Looking up Dex PC not contained in method, 0x" << std::hex << dex_pc
@@ -270,14 +260,16 @@
   ManagedStack fragment;
   self->PushManagedStackFragment(&fragment);
 
+  Runtime* runtime = Runtime::Current();
   // Call the invoke stub, passing everything as arguments.
-  if (UNLIKELY(!Runtime::Current()->IsStarted())){
+  if (UNLIKELY(!runtime->IsStarted())){
     LOG(INFO) << "Not invoking " << PrettyMethod(this) << " for a runtime that isn't started";
     if (result != NULL) {
       result->SetJ(0);
     }
   } else {
-    bool interpret = self->ReadFlag(kEnterInterpreter) && !IsNative() && !IsProxyMethod();
+    bool interpret = runtime->GetInstrumentation()->InterpretOnly() && !IsNative() &&
+        !IsProxyMethod();
     const bool kLogInvocationStartAndReturn = false;
     if (GetCode() != NULL) {
       if (!interpret) {
@@ -289,15 +281,15 @@
 #else
         (*art_quick_invoke_stub)(this, args, args_size, self, result, result_type);
 #endif
-        if (UNLIKELY(reinterpret_cast<int32_t>(self->GetException()) == -1)) {
+        if (UNLIKELY(reinterpret_cast<int32_t>(self->GetException(NULL)) == -1)) {
           // Unusual case where we were running LLVM generated code and an
           // exception was thrown to force the activations to be removed from the
           // stack. Continue execution in the interpreter.
-          JValue value;
           self->ClearException();
-          ShadowFrame* shadow_frame = self->GetAndClearDeoptimizationShadowFrame(&value);
+          ShadowFrame* shadow_frame = self->GetAndClearDeoptimizationShadowFrame(result);
+          self->SetTopOfStack(NULL, 0);
           self->SetTopOfShadowStack(shadow_frame);
-          interpreter::EnterInterpreterFromLLVM(self, shadow_frame, result);
+          interpreter::EnterInterpreterFromDeoptimize(self, shadow_frame, result);
         }
         if (kLogInvocationStartAndReturn) {
           LOG(INFO) << StringPrintf("Returned '%s' code=%p", PrettyMethod(this).c_str(), GetCode());
diff --git a/src/mirror/abstract_method.h b/src/mirror/abstract_method.h
index d10031a..9440915 100644
--- a/src/mirror/abstract_method.h
+++ b/src/mirror/abstract_method.h
@@ -321,6 +321,11 @@
     return GetFrameSizeInBytes() - kPointerSize;
   }
 
+  size_t GetSirtOffsetInBytes() const {
+    CHECK(IsNative());
+    return kPointerSize;
+  }
+
   bool IsRegistered() const;
 
   void RegisterNative(Thread* self, const void* native_method)
diff --git a/src/mirror/array.cc b/src/mirror/array.cc
index d0b3838..84c2dc6 100644
--- a/src/mirror/array.cc
+++ b/src/mirror/array.cc
@@ -18,6 +18,7 @@
 
 #include "class.h"
 #include "class-inl.h"
+#include "common_throws.h"
 #include "dex_file-inl.h"
 #include "gc/card_table-inl.h"
 #include "object-inl.h"
@@ -43,10 +44,10 @@
 
   // Check for overflow and throw OutOfMemoryError if this was an unreasonable request.
   size_t component_shift = sizeof(size_t) * 8 - 1 - CLZ(component_size);
-  if (data_size >> component_shift != size_t(component_count) || size < data_size) {
-    self->ThrowNewExceptionF("Ljava/lang/OutOfMemoryError;",
-        "%s of length %d would overflow",
-        PrettyDescriptor(array_class).c_str(), component_count);
+  if (UNLIKELY(data_size >> component_shift != size_t(component_count) || size < data_size)) {
+    self->ThrowOutOfMemoryError(StringPrintf("%s of length %d would overflow",
+                                             PrettyDescriptor(array_class).c_str(),
+                                             component_count).c_str());
     return NULL;
   }
 
@@ -108,8 +109,7 @@
   for (int i = 0; i < num_dimensions; i++) {
     int dimension = dimensions->Get(i);
     if (UNLIKELY(dimension < 0)) {
-      self->ThrowNewExceptionF("Ljava/lang/NegativeArraySizeException;",
-                               "Dimension %d: %d", i, dimension);
+      ThrowNegativeArraySizeException(StringPrintf("Dimension %d: %d", i, dimension).c_str());
       return NULL;
     }
   }
@@ -135,15 +135,12 @@
 }
 
 bool Array::ThrowArrayIndexOutOfBoundsException(int32_t index) const {
-  Thread::Current()->ThrowNewExceptionF("Ljava/lang/ArrayIndexOutOfBoundsException;",
-      "length=%i; index=%i", length_, index);
+  art::ThrowArrayIndexOutOfBoundsException(index, GetLength());
   return false;
 }
 
 bool Array::ThrowArrayStoreException(Object* object) const {
-  Thread::Current()->ThrowNewExceptionF("Ljava/lang/ArrayStoreException;",
-      "%s cannot be stored in an array of type %s",
-      PrettyTypeOf(object).c_str(), PrettyTypeOf(this).c_str());
+  art::ThrowArrayStoreException(object->GetClass(), this->GetClass());
   return false;
 }
 
diff --git a/src/mirror/class-inl.h b/src/mirror/class-inl.h
index ec92c19..d7afed6 100644
--- a/src/mirror/class-inl.h
+++ b/src/mirror/class-inl.h
@@ -24,7 +24,7 @@
 #include "dex_cache.h"
 #include "field.h"
 #include "iftable.h"
-#include "object_array.h"
+#include "object_array-inl.h"
 #include "runtime.h"
 #include "string.h"
 
diff --git a/src/mirror/class.cc b/src/mirror/class.cc
index ba3556e..15129ab 100644
--- a/src/mirror/class.cc
+++ b/src/mirror/class.cc
@@ -60,10 +60,22 @@
   if (new_status == kStatusError) {
     CHECK_NE(GetStatus(), kStatusError) << PrettyClass(this);
 
-    // stash current exception
+    // Stash current exception.
     Thread* self = Thread::Current();
-    SirtRef<Throwable> exception(self, self->GetException());
-    CHECK(exception.get() != NULL);
+    SirtRef<mirror::Object> old_throw_this_object(self, NULL);
+    SirtRef<mirror::AbstractMethod> old_throw_method(self, NULL);
+    SirtRef<mirror::Throwable> old_exception(self, NULL);
+    uint32_t old_throw_dex_pc;
+    {
+      ThrowLocation old_throw_location;
+      mirror::Throwable* old_exception_obj = self->GetException(&old_throw_location);
+      old_throw_this_object.reset(old_throw_location.GetThis());
+      old_throw_method.reset(old_throw_location.GetMethod());
+      old_exception.reset(old_exception_obj);
+      old_throw_dex_pc = old_throw_location.GetDexPc();
+      self->ClearException();
+    }
+    CHECK(old_exception.get() != NULL);
 
     // clear exception to call FindSystemClass
     self->ClearException();
@@ -71,15 +83,18 @@
     Class* eiie_class = class_linker->FindSystemClass("Ljava/lang/ExceptionInInitializerError;");
     CHECK(!self->IsExceptionPending());
 
-    // only verification errors, not initialization problems, should set a verify error.
-    // this is to ensure that ThrowEarlierClassFailure will throw NoClassDefFoundError in that case.
-    Class* exception_class = exception->GetClass();
+    // Only verification errors, not initialization problems, should set a verify error.
+    // This is to ensure that ThrowEarlierClassFailure will throw NoClassDefFoundError in that case.
+    Class* exception_class = old_exception->GetClass();
     if (!eiie_class->IsAssignableFrom(exception_class)) {
       SetVerifyErrorClass(exception_class);
     }
 
-    // restore exception
-    self->SetException(exception.get());
+    // Restore exception.
+    ThrowLocation gc_safe_throw_location(old_throw_this_object.get(), old_throw_method.get(),
+                                         old_throw_dex_pc);
+
+    self->SetException(gc_safe_throw_location, old_exception.get());
   }
   return SetField32(OFFSET_OF_OBJECT_MEMBER(Class, status_), new_status, false);
 }
diff --git a/src/mirror/object_test.cc b/src/mirror/object_test.cc
index eed96bd..5c7ec11 100644
--- a/src/mirror/object_test.cc
+++ b/src/mirror/object_test.cc
@@ -116,12 +116,12 @@
 
   EXPECT_TRUE(oa->Get(-1) == NULL);
   EXPECT_TRUE(soa.Self()->IsExceptionPending());
-  EXPECT_EQ(aioobe, soa.Self()->GetException()->GetClass());
+  EXPECT_EQ(aioobe, soa.Self()->GetException(NULL)->GetClass());
   soa.Self()->ClearException();
 
   EXPECT_TRUE(oa->Get(2) == NULL);
   EXPECT_TRUE(soa.Self()->IsExceptionPending());
-  EXPECT_EQ(aioobe, soa.Self()->GetException()->GetClass());
+  EXPECT_EQ(aioobe, soa.Self()->GetException(NULL)->GetClass());
   soa.Self()->ClearException();
 
   ASSERT_TRUE(oa->GetClass() != NULL);
@@ -166,12 +166,12 @@
 
   EXPECT_EQ(0, a->Get(-1));
   EXPECT_TRUE(soa.Self()->IsExceptionPending());
-  EXPECT_EQ(aioobe, soa.Self()->GetException()->GetClass());
+  EXPECT_EQ(aioobe, soa.Self()->GetException(NULL)->GetClass());
   soa.Self()->ClearException();
 
   EXPECT_EQ(0, a->Get(2));
   EXPECT_TRUE(soa.Self()->IsExceptionPending());
-  EXPECT_EQ(aioobe, soa.Self()->GetException()->GetClass());
+  EXPECT_EQ(aioobe, soa.Self()->GetException(NULL)->GetClass());
   soa.Self()->ClearException();
 }
 
@@ -231,7 +231,7 @@
   dims->Set(0, -1);
   multi = Array::CreateMultiArray(soa.Self(), c.get(), dims.get());
   EXPECT_TRUE(soa.Self()->IsExceptionPending());
-  EXPECT_EQ(PrettyDescriptor(soa.Self()->GetException()->GetClass()),
+  EXPECT_EQ(PrettyDescriptor(soa.Self()->GetException(NULL)->GetClass()),
             "java.lang.NegativeArraySizeException");
   soa.Self()->ClearException();
 
diff --git a/src/mirror/string.cc b/src/mirror/string.cc
index f571fb8..45a6779 100644
--- a/src/mirror/string.cc
+++ b/src/mirror/string.cc
@@ -103,8 +103,9 @@
   // bounds check itself.
   if (index < 0 || index >= count_) {
     Thread* self = Thread::Current();
-    self->ThrowNewExceptionF("Ljava/lang/StringIndexOutOfBoundsException;",
-        "length=%i; index=%i", count_, index);
+    ThrowLocation throw_location = self->GetCurrentLocationForThrow();
+    self->ThrowNewExceptionF(throw_location, "Ljava/lang/StringIndexOutOfBoundsException;",
+                             "length=%i; index=%i", count_, index);
     return 0;
   }
   return GetCharArray()->Get(index + GetOffset());
diff --git a/src/mirror/throwable.cc b/src/mirror/throwable.cc
index d1192b0..bbff9c2 100644
--- a/src/mirror/throwable.cc
+++ b/src/mirror/throwable.cc
@@ -35,7 +35,9 @@
 void Throwable::SetCause(Throwable* cause) {
   CHECK(cause != NULL);
   CHECK(cause != this);
-  CHECK(GetFieldObject<Throwable*>(OFFSET_OF_OBJECT_MEMBER(Throwable, cause_), false) == NULL);
+  Throwable* current_cause = GetFieldObject<Throwable*>(OFFSET_OF_OBJECT_MEMBER(Throwable, cause_),
+                                                        false);
+  CHECK(current_cause == NULL || current_cause == this);
   SetFieldObject(OFFSET_OF_OBJECT_MEMBER(Throwable, cause_), cause, false);
 }
 
diff --git a/src/monitor.cc b/src/monitor.cc
index 2377734..11790e5 100644
--- a/src/monitor.cc
+++ b/src/monitor.cc
@@ -254,10 +254,12 @@
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
   va_list args;
   va_start(args, fmt);
-  Thread::Current()->ThrowNewExceptionV("Ljava/lang/IllegalMonitorStateException;", fmt, args);
+  Thread* self = Thread::Current();
+  ThrowLocation throw_location = self->GetCurrentLocationForThrow();
+  self->ThrowNewExceptionV(throw_location, "Ljava/lang/IllegalMonitorStateException;", fmt, args);
   if (!Runtime::Current()->IsStarted()) {
     std::ostringstream ss;
-    Thread::Current()->Dump(ss);
+    self->Dump(ss);
     std::string str(ss.str());
     LOG(ERROR) << "IllegalMonitorStateException: " << str;
   }
@@ -411,8 +413,9 @@
                            bool interruptShouldThrow, ThreadState why) {
   // Enforce the timeout range.
   if (ms < 0 || ns < 0 || ns > 999999) {
-    Thread::Current()->ThrowNewExceptionF("Ljava/lang/IllegalArgumentException;",
-        "timeout arguments out of range: ms=%lld ns=%d", ms, ns);
+    ThrowLocation throw_location = self->GetCurrentLocationForThrow();
+    self->ThrowNewExceptionF(throw_location, "Ljava/lang/IllegalArgumentException;",
+                             "timeout arguments out of range: ms=%lld ns=%d", ms, ns);
     return;
   }
 
@@ -517,7 +520,8 @@
       self->interrupted_ = false;
     }
     if (interruptShouldThrow) {
-      Thread::Current()->ThrowNewException("Ljava/lang/InterruptedException;", NULL);
+      ThrowLocation throw_location = self->GetCurrentLocationForThrow();
+      self->ThrowNewException(throw_location, "Ljava/lang/InterruptedException;", NULL);
     }
   }
 }
diff --git a/src/monitor_android.cc b/src/monitor_android.cc
index d3ac143..9265cd6 100644
--- a/src/monitor_android.cc
+++ b/src/monitor_android.cc
@@ -77,7 +77,7 @@
   cp = EventLogWriteInt(cp, wait_ms);
 
   // Emit the source code file name, <= 37 bytes.
-  uintptr_t pc;
+  uint32_t pc;
   mirror::AbstractMethod* m = self->GetCurrentMethod(&pc);
   const char* filename;
   uint32_t line_number;
diff --git a/src/native/dalvik_system_DexFile.cc b/src/native/dalvik_system_DexFile.cc
index 7c6fbd9..d703f83 100644
--- a/src/native/dalvik_system_DexFile.cc
+++ b/src/native/dalvik_system_DexFile.cc
@@ -18,6 +18,7 @@
 
 #include "base/logging.h"
 #include "class_linker.h"
+#include "common_throws.h"
 #include "dex_file-inl.h"
 #include "gc/space.h"
 #include "image.h"
@@ -103,18 +104,18 @@
   }
   if (dex_file == NULL) {
     LOG(WARNING) << "Failed to open dex file: " << source;
-    Thread::Current()->ThrowNewExceptionF("Ljava/io/IOException;", "Unable to open dex file: %s",
-                                          source.c_str());
+    ThrowLocation throw_location = soa.Self()->GetCurrentLocationForThrow();
+    soa.Self()->ThrowNewExceptionF(throw_location, "Ljava/io/IOException;",
+                                   "Unable to open dex file: %s", source.c_str());
     return 0;
   }
   return static_cast<jint>(reinterpret_cast<uintptr_t>(dex_file));
 }
 
-static const DexFile* toDexFile(int dex_file_address)
-    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+static const DexFile* toDexFile(int dex_file_address) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
   const DexFile* dex_file = reinterpret_cast<const DexFile*>(static_cast<uintptr_t>(dex_file_address));
   if (dex_file == NULL) {
-    Thread::Current()->ThrowNewExceptionF("Ljava/lang/NullPointerException;", "dex_file == null");
+    ThrowNullPointerException(NULL, "dex_file == null");
   }
   return dex_file;
 }
@@ -188,7 +189,9 @@
   if (!OS::FileExists(filename.c_str())) {
     LOG(ERROR) << "DexFile_isDexOptNeeded file '" << filename.c_str() << "' does not exist";
     ScopedObjectAccess soa(env);
-    Thread::Current()->ThrowNewExceptionF("Ljava/io/FileNotFoundException;", "%s", filename.c_str());
+    ThrowLocation throw_location = soa.Self()->GetCurrentLocationForThrow();
+    soa.Self()->ThrowNewExceptionF(throw_location, "Ljava/io/FileNotFoundException;",
+                                   "%s", filename.c_str());
     return JNI_TRUE;
   }
 
diff --git a/src/native/dalvik_system_VMDebug.cc b/src/native/dalvik_system_VMDebug.cc
index dc07a31..992998e 100644
--- a/src/native/dalvik_system_VMDebug.cc
+++ b/src/native/dalvik_system_VMDebug.cc
@@ -18,6 +18,7 @@
 #include <unistd.h>
 
 #include "class_linker.h"
+#include "common_throws.h"
 #include "debugger.h"
 #include "hprof/hprof.h"
 #include "jni_internal.h"
@@ -68,8 +69,9 @@
   int fd = dup(originalFd);
   if (fd < 0) {
     ScopedObjectAccess soa(env);
-    Thread::Current()->ThrowNewExceptionF("Ljava/lang/RuntimeException;",
-                                          "dup(%d) failed: %s", originalFd, strerror(errno));
+    ThrowLocation throw_location = soa.Self()->GetCurrentLocationForThrow();
+    soa.Self()->ThrowNewExceptionF(throw_location, "Ljava/lang/RuntimeException;",
+                                   "dup(%d) failed: %s", originalFd, strerror(errno));
     return;
   }
 
@@ -90,7 +92,7 @@
 }
 
 static jboolean VMDebug_isMethodTracingActive(JNIEnv*, jclass) {
-  return Runtime::Current()->IsMethodTracingActive();
+  return Trace::IsMethodTracingActive();
 }
 
 static void VMDebug_stopMethodTracing(JNIEnv*, jclass) {
@@ -119,24 +121,26 @@
   return Dbg::LastDebuggerActivity();
 }
 
-static void VMDebug_startInstructionCounting(JNIEnv* env, jclass) {
+static void ThrowUnsupportedOperationException(JNIEnv* env) {
   ScopedObjectAccess soa(env);
-  Thread::Current()->ThrowNewException("Ljava/lang/UnsupportedOperationException;", "");
+  ThrowLocation throw_location = soa.Self()->GetCurrentLocationForThrow();
+  soa.Self()->ThrowNewException(throw_location, "Ljava/lang/UnsupportedOperationException;", NULL);
+}
+
+static void VMDebug_startInstructionCounting(JNIEnv* env, jclass) {
+  ThrowUnsupportedOperationException(env);
 }
 
 static void VMDebug_stopInstructionCounting(JNIEnv* env, jclass) {
-  ScopedObjectAccess soa(env);
-  Thread::Current()->ThrowNewException("Ljava/lang/UnsupportedOperationException;", "");
+  ThrowUnsupportedOperationException(env);
 }
 
 static void VMDebug_getInstructionCount(JNIEnv* env, jclass, jintArray /*javaCounts*/) {
-  ScopedObjectAccess soa(env);
-  Thread::Current()->ThrowNewException("Ljava/lang/UnsupportedOperationException;", "");
+  ThrowUnsupportedOperationException(env);
 }
 
 static void VMDebug_resetInstructionCount(JNIEnv* env, jclass) {
-  ScopedObjectAccess soa(env);
-  Thread::Current()->ThrowNewException("Ljava/lang/UnsupportedOperationException;", "");
+  ThrowUnsupportedOperationException(env);
 }
 
 static void VMDebug_printLoadedClasses(JNIEnv* env, jclass, jint flags) {
@@ -166,8 +170,7 @@
   // Only one of these may be NULL.
   if (javaFilename == NULL && javaFd == NULL) {
     ScopedObjectAccess soa(env);
-    Thread::Current()->ThrowNewException("Ljava/lang/NullPointerException;",
-                                         "fileName == null && fd == null");
+    ThrowNullPointerException(NULL, "fileName == null && fd == null");
     return;
   }
 
@@ -187,8 +190,7 @@
     fd = jniGetFDFromFileDescriptor(env, javaFd);
     if (fd < 0) {
       ScopedObjectAccess soa(env);
-      Thread::Current()->ThrowNewException("Ljava/lang/RuntimeException;",
-                                           "Invalid file descriptor");
+      ThrowRuntimeException("Invalid file descriptor");
       return;
     }
   }
diff --git a/src/native/dalvik_system_VMRuntime.cc b/src/native/dalvik_system_VMRuntime.cc
index a13d07a..d2ef43c 100644
--- a/src/native/dalvik_system_VMRuntime.cc
+++ b/src/native/dalvik_system_VMRuntime.cc
@@ -17,6 +17,7 @@
 #include <limits.h>
 
 #include "class_linker.h"
+#include "common_throws.h"
 #include "debugger.h"
 #include "dex_file-inl.h"
 #include "jni_internal.h"
@@ -57,11 +58,11 @@
 
   mirror::Class* element_class = soa.Decode<mirror::Class*>(javaElementClass);
   if (element_class == NULL) {
-    soa.Self()->ThrowNewException("Ljava/lang/NullPointerException;", "element class == null");
+    ThrowNullPointerException(NULL, "element class == null");
     return NULL;
   }
   if (length < 0) {
-    soa.Self()->ThrowNewExceptionF("Ljava/lang/NegativeArraySizeException;", "%d", length);
+    ThrowNegativeArraySizeException(length);
     return NULL;
   }
 
@@ -84,7 +85,7 @@
   ScopedObjectAccess soa(env);
   mirror::Array* array = soa.Decode<mirror::Array*>(javaArray);
   if (!array->IsArrayInstance()) {
-    soa.Self()->ThrowNewException("Ljava/lang/IllegalArgumentException;", "not an array");
+    ThrowIllegalArgumentException(NULL, "not an array");
     return 0;
   }
   // TODO: we should also check that this is a non-movable array.
diff --git a/src/native/java_lang_Class.cc b/src/native/java_lang_Class.cc
index 72f4c18..a729699 100644
--- a/src/native/java_lang_Class.cc
+++ b/src/native/java_lang_Class.cc
@@ -53,8 +53,9 @@
   // is especially handy for array types, since we want to avoid
   // auto-generating bogus array classes.
   if (!IsValidBinaryClassName(name.c_str())) {
-    Thread::Current()->ThrowNewExceptionF("Ljava/lang/ClassNotFoundException;",
-        "Invalid name: %s", name.c_str());
+    ThrowLocation throw_location = soa.Self()->GetCurrentLocationForThrow();
+    soa.Self()->ThrowNewExceptionF(throw_location, "Ljava/lang/ClassNotFoundException;",
+                                   "Invalid name: %s", name.c_str());
     return NULL;
   }
 
diff --git a/src/native/java_lang_String.cc b/src/native/java_lang_String.cc
index 44ab1ca..3e9c3f3 100644
--- a/src/native/java_lang_String.cc
+++ b/src/native/java_lang_String.cc
@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+#include "common_throws.h"
 #include "jni_internal.h"
 #include "mirror/string.h"
 #include "scoped_thread_state_change.h"
@@ -22,12 +23,11 @@
 namespace art {
 
 static jint String_compareTo(JNIEnv* env, jobject javaThis, jobject javaRhs) {
+  ScopedObjectAccess soa(env);
   if (UNLIKELY(javaRhs == NULL)) {
-    ScopedLocalRef<jclass> npe(env, env->FindClass("java/lang/NullPointerException"));
-    env->ThrowNew(npe.get(), "rhs == null");
+    ThrowNullPointerException(NULL, "rhs == null");
     return -1;
   } else {
-    ScopedObjectAccess soa(env);
     return soa.Decode<mirror::String*>(javaThis)->CompareTo(soa.Decode<mirror::String*>(javaRhs));
   }
 }
diff --git a/src/native/java_lang_System.cc b/src/native/java_lang_System.cc
index 5572623..d8df9d9 100644
--- a/src/native/java_lang_System.cc
+++ b/src/native/java_lang_System.cc
@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+#include "common_throws.h"
 #include "gc/card_table-inl.h"
 #include "jni_internal.h"
 #include "mirror/array.h"
@@ -171,31 +172,33 @@
 static void ThrowArrayStoreException_NotAnArray(const char* identifier, mirror::Object* array)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
   std::string actualType(PrettyTypeOf(array));
-  Thread::Current()->ThrowNewExceptionF("Ljava/lang/ArrayStoreException;",
-      "%s of type %s is not an array", identifier, actualType.c_str());
+  Thread* self = Thread::Current();
+  ThrowLocation throw_location = self->GetCurrentLocationForThrow();
+  self->ThrowNewExceptionF(throw_location, "Ljava/lang/ArrayStoreException;",
+                           "%s of type %s is not an array", identifier, actualType.c_str());
 }
 
 static void System_arraycopy(JNIEnv* env, jclass, jobject javaSrc, jint srcPos, jobject javaDst, jint dstPos, jint length) {
   ScopedObjectAccess soa(env);
 
   // Null pointer checks.
-  if (javaSrc == NULL) {
-    soa.Self()->ThrowNewException("Ljava/lang/NullPointerException;", "src == null");
+  if (UNLIKELY(javaSrc == NULL)) {
+    ThrowNullPointerException(NULL, "src == null");
     return;
   }
-  if (javaDst == NULL) {
-    soa.Self()->ThrowNewException("Ljava/lang/NullPointerException;", "dst == null");
+  if (UNLIKELY(javaDst == NULL)) {
+    ThrowNullPointerException(NULL, "dst == null");
     return;
   }
 
   // Make sure source and destination are both arrays.
   mirror::Object* srcObject = soa.Decode<mirror::Object*>(javaSrc);
   mirror::Object* dstObject = soa.Decode<mirror::Object*>(javaDst);
-  if (!srcObject->IsArrayInstance()) {
+  if (UNLIKELY(!srcObject->IsArrayInstance())) {
     ThrowArrayStoreException_NotAnArray("source", srcObject);
     return;
   }
-  if (!dstObject->IsArrayInstance()) {
+  if (UNLIKELY(!dstObject->IsArrayInstance())) {
     ThrowArrayStoreException_NotAnArray("destination", dstObject);
     return;
   }
@@ -205,21 +208,24 @@
   mirror::Class* dstComponentType = dstArray->GetClass()->GetComponentType();
 
   // Bounds checking.
-  if (srcPos < 0 || dstPos < 0 || length < 0 || srcPos > srcArray->GetLength() - length || dstPos > dstArray->GetLength() - length) {
-    soa.Self()->ThrowNewExceptionF("Ljava/lang/ArrayIndexOutOfBoundsException;",
-        "src.length=%d srcPos=%d dst.length=%d dstPos=%d length=%d",
-        srcArray->GetLength(), srcPos, dstArray->GetLength(), dstPos, length);
+  if (UNLIKELY(srcPos < 0 || dstPos < 0 || length < 0 || srcPos > srcArray->GetLength() - length || dstPos > dstArray->GetLength() - length)) {
+    ThrowLocation throw_location = soa.Self()->GetCurrentLocationForThrow();
+    soa.Self()->ThrowNewExceptionF(throw_location, "Ljava/lang/ArrayIndexOutOfBoundsException;",
+                                   "src.length=%d srcPos=%d dst.length=%d dstPos=%d length=%d",
+                                   srcArray->GetLength(), srcPos, dstArray->GetLength(), dstPos, length);
     return;
   }
 
   // Handle primitive arrays.
   if (srcComponentType->IsPrimitive() || dstComponentType->IsPrimitive()) {
     // If one of the arrays holds a primitive type the other array must hold the exact same type.
-    if (srcComponentType->IsPrimitive() != dstComponentType->IsPrimitive() || srcComponentType != dstComponentType) {
+    if (UNLIKELY(srcComponentType != dstComponentType)) {
       std::string srcType(PrettyTypeOf(srcArray));
       std::string dstType(PrettyTypeOf(dstArray));
-      soa.Self()->ThrowNewExceptionF("Ljava/lang/ArrayStoreException;",
-          "Incompatible types: src=%s, dst=%s", srcType.c_str(), dstType.c_str());
+      ThrowLocation throw_location = soa.Self()->GetCurrentLocationForThrow();
+      soa.Self()->ThrowNewExceptionF(throw_location, "Ljava/lang/ArrayStoreException;",
+                                     "Incompatible types: src=%s, dst=%s",
+                                     srcType.c_str(), dstType.c_str());
       return;
     }
 
@@ -299,12 +305,13 @@
   }
 
   Runtime::Current()->GetHeap()->WriteBarrierArray(dstArray, dstPos, length);
-  if (i != length) {
+  if (UNLIKELY(i != length)) {
     std::string actualSrcType(PrettyTypeOf(o));
     std::string dstType(PrettyTypeOf(dstArray));
-    soa.Self()->ThrowNewExceptionF("Ljava/lang/ArrayStoreException;",
-        "source[%d] of type %s cannot be stored in destination array of type %s",
-        srcPos + i, actualSrcType.c_str(), dstType.c_str());
+    ThrowLocation throw_location = soa.Self()->GetCurrentLocationForThrow();
+    soa.Self()->ThrowNewExceptionF(throw_location, "Ljava/lang/ArrayStoreException;",
+                                   "source[%d] of type %s cannot be stored in destination array of type %s",
+                                   srcPos + i, actualSrcType.c_str(), dstType.c_str());
     return;
   }
 }
diff --git a/src/native/java_lang_Thread.cc b/src/native/java_lang_Thread.cc
index ca4be9d..7ccfaaa 100644
--- a/src/native/java_lang_Thread.cc
+++ b/src/native/java_lang_Thread.cc
@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+#include "common_throws.h"
 #include "debugger.h"
 #include "jni_internal.h"
 #include "monitor.h"
@@ -90,7 +91,7 @@
   ScopedObjectAccess soa(env);
   mirror::Object* object = soa.Decode<mirror::Object*>(java_object);
   if (object == NULL) {
-    Thread::Current()->ThrowNewException("Ljava/lang/NullPointerException;", "object == null");
+    ThrowNullPointerException(NULL, "object == null");
     return JNI_FALSE;
   }
   MutexLock mu(soa.Self(), *Locks::thread_list_lock_);
diff --git a/src/native/java_lang_reflect_Array.cc b/src/native/java_lang_reflect_Array.cc
index af7a77a..45ec0ad 100644
--- a/src/native/java_lang_reflect_Array.cc
+++ b/src/native/java_lang_reflect_Array.cc
@@ -15,6 +15,7 @@
  */
 
 #include "class_linker.h"
+#include "common_throws.h"
 #include "dex_file-inl.h"
 #include "jni_internal.h"
 #include "mirror/class-inl.h"
@@ -44,7 +45,7 @@
   DCHECK(javaElementClass != NULL);
   mirror::Class* element_class = soa.Decode<mirror::Class*>(javaElementClass);
   if (UNLIKELY(length < 0)) {
-    soa.Self()->ThrowNewExceptionF("Ljava/lang/NegativeArraySizeException;", "%d", length);
+    ThrowNegativeArraySizeException(length);
     return NULL;
   }
   std::string descriptor("[");
diff --git a/src/native/java_lang_reflect_Constructor.cc b/src/native/java_lang_reflect_Constructor.cc
index fb84dfd..9180217 100644
--- a/src/native/java_lang_reflect_Constructor.cc
+++ b/src/native/java_lang_reflect_Constructor.cc
@@ -37,9 +37,12 @@
   ScopedObjectAccess soa(env);
   mirror::AbstractMethod* m = soa.Decode<mirror::Object*>(javaMethod)->AsMethod();
   mirror::Class* c = m->GetDeclaringClass();
-  if (c->IsAbstract()) {
-    soa.Self()->ThrowNewExceptionF("Ljava/lang/InstantiationException;",
-        "Can't instantiate abstract class %s", PrettyDescriptor(c).c_str());
+  if (UNLIKELY(c->IsAbstract())) {
+    ThrowLocation throw_location = soa.Self()->GetCurrentLocationForThrow();
+    soa.Self()->ThrowNewExceptionF(throw_location, "Ljava/lang/InstantiationException;",
+                                   "Can't instantiate %s %s",
+                                   c->IsInterface() ? "interface" : "abstract class",
+                                   PrettyDescriptor(c).c_str());
     return NULL;
   }
 
diff --git a/src/native/java_lang_reflect_Field.cc b/src/native/java_lang_reflect_Field.cc
index 922fe00..b0daa91 100644
--- a/src/native/java_lang_reflect_Field.cc
+++ b/src/native/java_lang_reflect_Field.cc
@@ -16,6 +16,7 @@
 
 #include "class_linker.h"
 #include "class_linker-inl.h"
+#include "common_throws.h"
 #include "dex_file-inl.h"
 #include "jni_internal.h"
 #include "mirror/class-inl.h"
@@ -71,22 +72,23 @@
     // Never okay.
     break;
   }
-  soa.Self()->ThrowNewExceptionF("Ljava/lang/IllegalArgumentException;",
-      "Not a primitive field: %s", PrettyField(f).c_str());
+  ThrowIllegalArgumentException(NULL,
+                                StringPrintf("Not a primitive field: %s",
+                                             PrettyField(f).c_str()).c_str());
   return false;
 }
 
-static bool CheckReceiver(const ScopedObjectAccess& soa, jobject javaObj, mirror::Field* f,
-                          mirror::Object*& o)
+static bool CheckReceiver(const ScopedObjectAccess& soa, jobject j_rcvr, mirror::Field* f,
+                          mirror::Object*& class_or_rcvr)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
   if (f->IsStatic()) {
-    o = f->GetDeclaringClass();
+    class_or_rcvr = f->GetDeclaringClass();
     return true;
   }
 
-  o = soa.Decode<mirror::Object*>(javaObj);
+  class_or_rcvr = soa.Decode<mirror::Object*>(j_rcvr);
   mirror::Class* declaringClass = f->GetDeclaringClass();
-  if (!VerifyObjectInClass(o, declaringClass)) {
+  if (!VerifyObjectInClass(class_or_rcvr, declaringClass)) {
     return false;
   }
   return true;
@@ -126,8 +128,8 @@
   // Widen it if necessary (and possible).
   JValue wide_value;
   mirror::Class* dst_type = Runtime::Current()->GetClassLinker()->FindPrimitiveClass(dst_descriptor);
-  if (!ConvertPrimitiveValue(FieldHelper(f).GetTypeAsPrimitiveType(), dst_type->GetPrimitiveType(),
-                             field_value, wide_value)) {
+  if (!ConvertPrimitiveValue(NULL, false, FieldHelper(f).GetTypeAsPrimitiveType(),
+                             dst_type->GetPrimitiveType(), field_value, wide_value)) {
     return JValue();
   }
   return wide_value;
@@ -205,8 +207,8 @@
     // Else fall through to report an error.
   case Primitive::kPrimVoid:
     // Never okay.
-    Thread::Current()->ThrowNewExceptionF("Ljava/lang/IllegalArgumentException;",
-        "Not a primitive field: %s", PrettyField(f).c_str());
+    ThrowIllegalArgumentException(NULL, StringPrintf("Not a primitive field: %s",
+                                                     PrettyField(f).c_str()).c_str());
     return;
   }
 
@@ -247,15 +249,15 @@
   }
   FieldHelper fh(f);
   if (!fh.IsPrimitiveType()) {
-    soa.Self()->ThrowNewExceptionF("Ljava/lang/IllegalArgumentException;",
-        "Not a primitive field: %s", PrettyField(f).c_str());
+    ThrowIllegalArgumentException(NULL, StringPrintf("Not a primitive field: %s",
+                                                     PrettyField(f).c_str()).c_str());
     return;
   }
 
   // Widen the value if necessary (and possible).
   JValue wide_value;
   mirror::Class* src_type = Runtime::Current()->GetClassLinker()->FindPrimitiveClass(src_descriptor);
-  if (!ConvertPrimitiveValue(src_type->GetPrimitiveType(), fh.GetTypeAsPrimitiveType(),
+  if (!ConvertPrimitiveValue(NULL, false, src_type->GetPrimitiveType(), fh.GetTypeAsPrimitiveType(),
                              new_value, wide_value)) {
     return;
   }
diff --git a/src/nth_caller_visitor.h b/src/nth_caller_visitor.h
index 7d9feb6..c32a46a 100644
--- a/src/nth_caller_visitor.h
+++ b/src/nth_caller_visitor.h
@@ -18,6 +18,7 @@
 #define ART_SRC_NTH_CALLER_VISITOR_H_
 
 #include "mirror/abstract_method.h"
+#include "locks.h"
 #include "stack.h"
 
 namespace art {
@@ -25,19 +26,32 @@
 
 // Walks up the stack 'n' callers, when used with Thread::WalkStack.
 struct NthCallerVisitor : public StackVisitor {
-  NthCallerVisitor(Thread* thread, size_t n)
-      : StackVisitor(thread, NULL), n(n), count(0), caller(NULL) {}
+  NthCallerVisitor(Thread* thread, size_t n, bool include_runtime_and_upcalls = false)
+      : StackVisitor(thread, NULL), n(n), include_runtime_and_upcalls_(include_runtime_and_upcalls),
+        count(0), caller(NULL) {}
 
-  bool VisitFrame() {
-    DCHECK(caller == NULL);
-    if (count++ == n) {
-      caller = GetMethod();
-      return false;
+  bool VisitFrame() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+    mirror::AbstractMethod* m = GetMethod();
+    bool do_count = false;
+    if (m == NULL || m->IsRuntimeMethod()) {
+      // Upcall.
+      do_count = include_runtime_and_upcalls_;
+    } else {
+      do_count = true;
+    }
+    if (do_count) {
+      DCHECK(caller == NULL);
+      if (count == n) {
+        caller = m;
+        return false;
+      }
+      count++;
     }
     return true;
   }
 
-  size_t n;
+  const size_t n;
+  const bool include_runtime_and_upcalls_;
   size_t count;
   mirror::AbstractMethod* caller;
 };
diff --git a/src/oat/runtime/arm/oat_support_entrypoints_arm.cc b/src/oat/runtime/arm/oat_support_entrypoints_arm.cc
index 58341bf..1276f78 100644
--- a/src/oat/runtime/arm/oat_support_entrypoints_arm.cc
+++ b/src/oat/runtime/arm/oat_support_entrypoints_arm.cc
@@ -33,10 +33,6 @@
 extern "C" void art_quick_can_put_array_element_from_code(void*, void*);
 extern "C" void art_quick_check_cast_from_code(void*, void*);
 
-// Debug entrypoints.
-extern void DebugMe(mirror::AbstractMethod* method, uint32_t info);
-extern "C" void art_quick_update_debugger(void*, void*, int32_t, void*);
-
 // DexCache entrypoints.
 extern "C" void* art_quick_initialize_static_storage_from_code(uint32_t, void*);
 extern "C" void* art_quick_initialize_type_from_code(uint32_t, void*);
@@ -145,10 +141,6 @@
   points->pCanPutArrayElementFromCode = art_quick_can_put_array_element_from_code;
   points->pCheckCastFromCode = art_quick_check_cast_from_code;
 
-  // Debug
-  points->pDebugMe = DebugMe;
-  points->pUpdateDebuggerFromCode = NULL; // Controlled by SetDebuggerUpdatesEnabled.
-
   // DexCache
   points->pInitializeStaticStorage = art_quick_initialize_static_storage_from_code;
   points->pInitializeTypeAndVerifyAccessFromCode = art_quick_initialize_type_and_verify_access_from_code;
@@ -236,10 +228,6 @@
   points->pThrowStackOverflowFromCode = art_quick_throw_stack_overflow_from_code;
 };
 
-void ChangeDebuggerEntryPoint(EntryPoints* points, bool enabled) {
-  points->pUpdateDebuggerFromCode = (enabled ? art_quick_update_debugger : NULL);
-}
-
 uintptr_t GetInstrumentationExitPc() {
   return reinterpret_cast<uintptr_t>(art_quick_instrumentation_exit_from_code);
 }
diff --git a/src/oat/runtime/arm/runtime_support_arm.S b/src/oat/runtime/arm/runtime_support_arm.S
index fe7d69f..96b3980 100644
--- a/src/oat/runtime/arm/runtime_support_arm.S
+++ b/src/oat/runtime/arm/runtime_support_arm.S
@@ -340,22 +340,6 @@
 END art_quick_invoke_stub
 
     /*
-     * On entry, r0 and r1 must be preserved, r2 is dex PC
-     */
-    .extern artUpdateDebuggerFromCode
-ENTRY art_quick_update_debugger
-    mov    r3, r0         @ stash away r0 so that it's saved as if it were an argument
-    SETUP_REF_AND_ARGS_CALLEE_SAVE_FRAME
-    mov    r0, r2         @ arg0 is dex PC
-    mov    r1, rSELF      @ arg1 is Thread*
-    mov    r2, sp         @ arg2 is sp
-    bl     artUpdateDebuggerFromCode      @ artUpdateDebuggerFromCode(int32_t, Thread*, Method**)
-    RESTORE_REF_AND_ARGS_CALLEE_SAVE_FRAME
-    mov    r0, r3         @ restore original r0
-    bx     lr
-END art_quick_update_debugger
-
-    /*
      * On entry r0 is uint32_t* gprs_ and r1 is uint32_t* fprs_
      */
 ENTRY art_quick_do_long_jump
@@ -979,21 +963,21 @@
     .extern artInstrumentationMethodEntryFromCode
     .extern artInstrumentationMethodExitFromCode
 ENTRY art_quick_instrumentation_entry_from_code
-    mov   r12, sp        @ remember bottom of caller's frame
-    push  {r0-r3}        @ save arguments (4 words)
-    .save {r0-r3}
+    SETUP_REF_AND_ARGS_CALLEE_SAVE_FRAME
+    str   r0, [sp, #4]     @ preserve r0
+    mov   r12, sp          @ remember sp
+    str   lr, [sp, #-16]!  @ expand the frame and pass LR
+    .pad #16
     .cfi_adjust_cfa_offset 16
-    .cfi_rel_offset r0, 0
-    .cfi_rel_offset r1, 4
-    .cfi_rel_offset r2, 8
-    .cfi_rel_offset r3, 12
-    mov   r1, r9         @ pass Thread::Current
-    mov   r2, r12        @ pass SP
-    mov   r3, lr         @ pass LR
-    blx   artInstrumentationMethodEntryFromCode  @ (Method*, Thread*, SP, LR)
-    mov   r12, r0        @ r12 holds reference to code
-    pop   {r0-r3}        @ restore arguments
+    .cfi_rel_offset lr, 0
+    mov   r2, r9         @ pass Thread::Current
+    mov   r3, r12        @ pass SP
+    blx   artInstrumentationMethodEntryFromCode  @ (Method*, Object*, Thread*, SP, LR)
+    add   sp, #16        @ remove out argument and padding from stack
     .cfi_adjust_cfa_offset -16
+    mov   r12, r0        @ r12 holds reference to code
+    ldr   r0, [sp, #4]   @ restore r0
+    RESTORE_REF_AND_ARGS_CALLEE_SAVE_FRAME
     blx   r12            @ call method with lr set to art_quick_instrumentation_exit_from_code
 END art_quick_instrumentation_entry_from_code
     .type art_quick_instrumentation_exit_from_code, #function
@@ -1001,51 +985,44 @@
 art_quick_instrumentation_exit_from_code:
     .cfi_startproc
     .fnstart
+    mov   lr, #0         @ link register is to here, so clobber with 0 for later checks
+    SETUP_REF_ONLY_CALLEE_SAVE_FRAME
     mov   r12, sp        @ remember bottom of caller's frame
     push  {r0-r1}        @ save return value
     .save {r0-r1}
     .cfi_adjust_cfa_offset 8
     .cfi_rel_offset r0, 0
     .cfi_rel_offset r1, 4
-    sub   sp, #8         @ align stack
+    sub   sp, #8         @ space for return value argument
     .pad #8
     .cfi_adjust_cfa_offset 8
+    strd r0, [sp]        @ r0/r1 -> [sp] for fpr_res
+    mov   r2, r0         @ pass return value as gpr_res
+    mov   r3, r1
     mov   r0, r9         @ pass Thread::Current
     mov   r1, r12        @ pass SP
-    blx   artInstrumentationMethodExitFromCode  @ (Thread*, SP)
+    blx   artInstrumentationMethodExitFromCode  @ (Thread*, SP, gpr_res, fpr_res)
     add   sp, #8
     .cfi_adjust_cfa_offset -8
+
     mov   r2, r0         @ link register saved by instrumentation
     mov   lr, r1         @ r1 is holding link register if we're to bounce to deoptimize
     pop   {r0, r1}       @ restore return value
-    .cfi_adjust_cfa_offset -8
+    add sp, #32          @ remove callee save frame
+    .cfi_adjust_cfa_offset -32
     bx    r2             @ return
 END art_quick_instrumentation_exit_from_code
 
     /*
-     * The thread's enter interpreter flag is set and so we should transition to the interpreter
-     * rather than allow execution to continue in the frame below. There may be live results in
-     * registers depending on how complete the operation is when we safepoint - for example, a
-     * set operation may have completed while a get operation needs writing back into the vregs.
+     * Instrumentation has requested that we deoptimize into the interpreter. The deoptimization
+     * will long jump to the upcall with a special exception of -1.
      */
     .extern artDeoptimize
-    .extern artEnterInterpreterFromDeoptimize
 ENTRY art_quick_deoptimize
     SETUP_REF_ONLY_CALLEE_SAVE_FRAME
-    mov    r2, r9         @ Set up args.
-    mov    r3, sp
-    blx    artDeoptimize  @ artDeoptimize(return value, Thread*, SP)
-                          @ Returns caller method's frame size.
-    RESTORE_REF_ONLY_CALLEE_SAVE_FRAME
-    cmp    r0, #0         @ Was the caller an upcall?
-    bxeq   lr             @ Return if caller was upcall.
-    add    r12, sp, r0    @ r12 == bottom of caller's frame.
-    ldr    lr, [r12, #-4] @ Restore lr.
-    mov    sp, r12        @ Remove frame.
-    SETUP_REF_ONLY_CALLEE_SAVE_FRAME
-    blx     artEnterInterpreterFromDeoptimize  @ Enter interpreter, callee-save ends stack fragment.
-    RESTORE_REF_ONLY_CALLEE_SAVE_FRAME
-    bx lr                 @ Return to caller.
+    mov    r0, r9         @ Set up args.
+    mov    r1, sp
+    blx    artDeoptimize  @ artDeoptimize(Thread*, SP)
 END art_quick_deoptimize
 
     /*
diff --git a/src/oat/runtime/mips/oat_support_entrypoints_mips.cc b/src/oat/runtime/mips/oat_support_entrypoints_mips.cc
index ea861e8..599b14c 100644
--- a/src/oat/runtime/mips/oat_support_entrypoints_mips.cc
+++ b/src/oat/runtime/mips/oat_support_entrypoints_mips.cc
@@ -33,10 +33,6 @@
 extern "C" void art_quick_can_put_array_element_from_code(void*, void*);
 extern "C" void art_quick_check_cast_from_code(void*, void*);
 
-// Debug entrypoints.
-extern void DebugMe(mirror::AbstractMethod* method, uint32_t info);
-extern "C" void art_quick_update_debugger(void*, void*, int32_t, void*);
-
 // DexCache entrypoints.
 extern "C" void* art_quick_initialize_static_storage_from_code(uint32_t, void*);
 extern "C" void* art_quick_initialize_type_from_code(uint32_t, void*);
@@ -147,10 +143,6 @@
   points->pCanPutArrayElementFromCode = art_quick_can_put_array_element_from_code;
   points->pCheckCastFromCode = art_quick_check_cast_from_code;
 
-  // Debug
-  points->pDebugMe = DebugMe;
-  points->pUpdateDebuggerFromCode = NULL; // Controlled by SetDebuggerUpdatesEnabled.
-
   // DexCache
   points->pInitializeStaticStorage = art_quick_initialize_static_storage_from_code;
   points->pInitializeTypeAndVerifyAccessFromCode = art_quick_initialize_type_and_verify_access_from_code;
@@ -237,10 +229,6 @@
   points->pThrowStackOverflowFromCode = art_quick_throw_stack_overflow_from_code;
 };
 
-void ChangeDebuggerEntryPoint(EntryPoints* points, bool enabled) {
-  points->pUpdateDebuggerFromCode = (enabled ? art_quick_update_debugger : NULL);
-}
-
 uintptr_t GetInstrumentationExitPc() {
   return reinterpret_cast<uintptr_t>(art_quick_instrumentation_exit_from_code);
 }
diff --git a/src/oat/runtime/mips/runtime_support_mips.S b/src/oat/runtime/mips/runtime_support_mips.S
index 0fc2437..529fd0d 100644
--- a/src/oat/runtime/mips/runtime_support_mips.S
+++ b/src/oat/runtime/mips/runtime_support_mips.S
@@ -204,24 +204,6 @@
 .endm
 
     /*
-     * On entry, $a0 and $a1 must be preserved, $a2 is dex PC
-     */
-    .extern artUpdateDebuggerFromCode
-ENTRY art_quick_update_debugger
-    GENERATE_GLOBAL_POINTER
-    move    $a3, $a0        # stash away $a0 so that it's saved as if it were an argument
-    SETUP_REF_AND_ARGS_CALLEE_SAVE_FRAME
-    move    $a0, $a2        # arg0 is dex PC
-    move    $a1, rSELF      # arg1 is Thread*
-    move    $a2, $sp        # arg2 is $sp
-    jal     artUpdateDebuggerFromCode      # artUpdateDebuggerFromCode(int32_t, Thread*, Method**)
-    nop
-    RESTORE_REF_AND_ARGS_CALLEE_SAVE_FRAME
-    jr      $ra
-    move    $a0, $a3        # restore original $a0
-END art_quick_update_debugger
-
-    /*
      * On entry $a0 is uint32_t* gprs_ and $a1 is uint32_t* fprs_
      * FIXME: just guessing about the shape of the jmpbuf.  Where will pc be?
      */
@@ -989,29 +971,22 @@
     .extern artInstrumentationMethodExitFromCode
 ENTRY art_quick_instrumentation_entry_from_code
     GENERATE_GLOBAL_POINTER
+    SETUP_REF_AND_ARGS_CALLEE_SAVE_FRAME
     move     $t0, $sp       # remember bottom of caller's frame
-    addiu    $sp, $sp, -16  # save arguments (4 words)
-    .cfi_adjust_cfa_offset 16
-    sw       $a0, 0($sp)
-    .cfi_rel_offset 4, 0
-    sw       $a1, 4($sp)
-    .cfi_rel_offset 5, 4
-    sw       $a2, 8($sp)
-    .cfi_rel_offset 6, 8
-    sw       $a3, 12($sp)
-    .cfi_rel_offset 7, 12
-    move     $a3, $ra       # pass $ra
-    move     $a2, $t0       # pass $sp
-    jal      artInstrumentationMethodEntryFromCode  # (Method*, Thread*, SP, LR)
-    move     $a1, rSELF     # pass Thread::Current
+    addiu    $sp, $sp, -32  # space for args, pad (3 words), arguments (5 words)
+    .cfi_adjust_cfa_offset 32
+    sw       $a0, 28($sp)   # save arg0
+    sw       $ra, 16($sp)   # pass $ra
+    move     $a3, $t0       # pass $sp
+    jal      artInstrumentationMethodEntryFromCode  # (Method*, Object*, Thread*, SP, LR)
+    move     $a2, rSELF     # pass Thread::Current
     move     $t9, $v0       # $t9 holds reference to code
-    lw       $a0, 0($sp)
-    lw       $a1, 4($sp)
-    lw       $a2, 8($sp)
-    lw       $a3, 12($sp)
+    lw       $a0, 28($sp)   # restore arg0
+    addiu    $sp, $sp, 32   # remove args
+    .cfi_adjust_cfa_offset -32
+    RESTORE_REF_AND_ARGS_CALLEE_SAVE_FRAME
     jalr     $t9            # call method
-    addiu    $sp, $sp, 16
-    .cfi_adjust_cfa_offset -16
+    nop
 END art_quick_instrumentation_entry_from_code
     /* intentional fallthrough */
     .global art_quick_instrumentation_exit_from_code
@@ -1020,53 +995,46 @@
     addiu    $t9, $ra, 4    # put current address into $t9 to rebuild $gp
     GENERATE_GLOBAL_POINTER
     move     $t0, $sp       # remember bottom of caller's frame
-    addiu    $sp, $sp, -16  # save return values
-    .cfi_adjust_cfa_offset 16
-    sw       $v0, 0($sp)
+    SETUP_REF_ONLY_CALLEE_SAVE_FRAME
+    addiu    $sp, $sp, -48  # save return values and set up args
+    .cfi_adjust_cfa_offset 48
+    sw       $v0, 32($sp)
     .cfi_rel_offset 2, 0
-    sw       $v1, 4($sp)
+    sw       $v1, 36($sp)
     .cfi_rel_offset 3, 4
+    s.s      $f0, 40($sp)
+    s.s      $f1, 44($sp)
+    s.s      $f0, 16($sp)   # pass fpr result
+    s.s      $f1, 20($sp)
+    move     $a2, $v0       # pass gpr result
+    move     $a3, $v1
     move     $a1, $t0       # pass $sp
-    jal      artInstrumentationMethodExitFromCode  # (Thread*, SP)
+    jal      artInstrumentationMethodExitFromCode  # (Thread*, SP, gpr_res, fpr_res)
     move     $a0, rSELF     # pass Thread::Current
     move     $t0, $v0       # set aside returned link register
     move     $ra, $v1       # set link register for deoptimization
-    lw       $v0, 0($sp)
-    lw       $v1, 4($sp)
+    lw       $v0, 32($sp)   # restore return values
+    lw       $v1, 36($sp)
+    l.s      $f0, 40($sp)
+    l.s      $f1, 44($sp)
     jr       $t0            # return
-    addiu    $sp, $sp, 16
-    .cfi_adjust_cfa_offset -16
+    addiu    $sp, $sp, 112  # 48 bytes of args + 64 bytes of callee save frame
+    .cfi_adjust_cfa_offset -112
 END art_quick_instrumentation_exit_from_code
 
     /*
-     * The thread's enter interpreter flag is set and so we should transition to the interpreter
-     * rather than allow execution to continue in the frame below. There may be live results in
-     * registers depending on how complete the operation is when we safepoint - for example, a
-     * set operation may have completed while a get operation needs writing back into the vregs.
+     * Instrumentation has requested that we deoptimize into the interpreter. The deoptimization
+     * will long jump to the upcall with a special exception of -1.
      */
     .extern artDeoptimize
     .extern artEnterInterpreterFromDeoptimize
 ENTRY art_quick_deoptimize
     GENERATE_GLOBAL_POINTER
     SETUP_REF_ONLY_CALLEE_SAVE_FRAME
-    move     $a0, $v0       # pass first half of return value
-    move     $a1, $v1       # pass second half of return value
-    move     $a2, rSELF     # pass Thread::current
-    jal      artDeoptimize  # artDeoptimize(return value, Thread*, SP)
+    move     $a0, rSELF     # pass Thread::current
+    jal      artDeoptimize  # artDeoptimize(Thread*, SP)
                             # Returns caller method's frame size.
-    move     $a3, $sp       # pass $sp
-    RESTORE_REF_ONLY_CALLEE_SAVE_FRAME
-    beqz     $v0, 1f        # Return if caller was upcall.
-    add      $t9, $sp, $v0  # $t9 == bottom of caller's frame.
-    lw       $ra, -4($t9)   # Restore $ra.
-    move     $sp, $t9       # Remove frame.
-    SETUP_REF_ONLY_CALLEE_SAVE_FRAME
-    jal      artEnterInterpreterFromDeoptimize  # Enter interpreter, callee-save ends stack fragment.
-    nop
-    RESTORE_REF_ONLY_CALLEE_SAVE_FRAME
-1:
-    jr       $ra            # Return to caller.
-    nop
+    move     $a1, $sp       # pass $sp
 END art_quick_deoptimize
 
     /*
diff --git a/src/oat/runtime/oat_support_entrypoints.h b/src/oat/runtime/oat_support_entrypoints.h
index ee59df4..9cd9cc7 100644
--- a/src/oat/runtime/oat_support_entrypoints.h
+++ b/src/oat/runtime/oat_support_entrypoints.h
@@ -46,10 +46,6 @@
   void (*pCanPutArrayElementFromCode)(void*, void*);
   void (*pCheckCastFromCode)(void*, void*);
 
-  // Debug
-  void (*pDebugMe)(mirror::AbstractMethod*, uint32_t);
-  void (*pUpdateDebuggerFromCode)(void*, void*, int32_t, void*);
-
   // DexCache
   void* (*pInitializeStaticStorage)(uint32_t, void*);
   void* (*pInitializeTypeAndVerifyAccessFromCode)(uint32_t, void*);
diff --git a/src/oat/runtime/support_cast.cc b/src/oat/runtime/support_cast.cc
index 0b1fb74..fe91e61 100644
--- a/src/oat/runtime/support_cast.cc
+++ b/src/oat/runtime/support_cast.cc
@@ -32,19 +32,16 @@
 }
 
 // Check whether it is safe to cast one class to the other, throw exception and return -1 on failure
-extern "C" int artCheckCastFromCode(const mirror::Class* a, const mirror::Class* b, Thread* self,
-                                    mirror::AbstractMethod** sp)
+extern "C" int artCheckCastFromCode(mirror::Class* src_type, mirror::Class* dest_type,
+                                    Thread* self, mirror::AbstractMethod** sp)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
-  DCHECK(a->IsClass()) << PrettyClass(a);
-  DCHECK(b->IsClass()) << PrettyClass(b);
-  if (LIKELY(b->IsAssignableFrom(a))) {
+  DCHECK(src_type->IsClass()) << PrettyClass(src_type);
+  DCHECK(dest_type->IsClass()) << PrettyClass(dest_type);
+  if (LIKELY(dest_type->IsAssignableFrom(src_type))) {
     return 0;  // Success
   } else {
     FinishCalleeSaveFrameSetup(self, sp, Runtime::kRefsOnly);
-    self->ThrowNewExceptionF("Ljava/lang/ClassCastException;",
-        "%s cannot be cast to %s",
-        PrettyDescriptor(a).c_str(),
-        PrettyDescriptor(b).c_str());
+    ThrowClassCastException(dest_type, src_type);
     return -1;  // Failure
   }
 }
@@ -63,10 +60,7 @@
     return 0;  // Success
   } else {
     FinishCalleeSaveFrameSetup(self, sp, Runtime::kRefsOnly);
-    self->ThrowNewExceptionF("Ljava/lang/ArrayStoreException;",
-        "%s cannot be stored in an array of type %s",
-        PrettyDescriptor(element_class).c_str(),
-        PrettyDescriptor(array_class).c_str());
+    ThrowArrayStoreException(element_class, array_class);
     return -1;  // Failure
   }
 }
diff --git a/src/oat/runtime/support_debug.cc b/src/oat/runtime/support_debug.cc
deleted file mode 100644
index 0d67dd9..0000000
--- a/src/oat/runtime/support_debug.cc
+++ /dev/null
@@ -1,44 +0,0 @@
-/*
- * Copyright (C) 2012 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#include "callee_save_frame.h"
-#include "debugger.h"
-
-namespace art {
-
-/*
- * Report location to debugger.  Note: dex_pc is the current offset within
- * the method.  However, because the offset alone cannot distinguish between
- * method entry and offset 0 within the method, we'll use an offset of -1
- * to denote method entry.
- */
-extern "C" void artUpdateDebuggerFromCode(int32_t dex_pc, Thread* self, mirror::AbstractMethod** sp)
-    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
-  FinishCalleeSaveFrameSetup(self, sp,  Runtime::kRefsAndArgs);
-  Dbg::UpdateDebugger(dex_pc, self);
-}
-
-// Temporary debugging hook for compiler.
-extern void DebugMe(mirror::AbstractMethod* method, uint32_t info)
-    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
-  LOG(INFO) << "DebugMe";
-  if (method != NULL) {
-    LOG(INFO) << PrettyMethod(method);
-  }
-  LOG(INFO) << "Info: " << info;
-}
-
-}  // namespace art
diff --git a/src/oat/runtime/support_deoptimize.cc b/src/oat/runtime/support_deoptimize.cc
index 2cc5dd3..0b0a7c3 100644
--- a/src/oat/runtime/support_deoptimize.cc
+++ b/src/oat/runtime/support_deoptimize.cc
@@ -28,88 +28,11 @@
 
 namespace art {
 
-extern "C" uint64_t artDeoptimize(JValue ret_val, Thread* self, mirror::AbstractMethod** sp)
+extern "C" void artDeoptimize(Thread* self, mirror::AbstractMethod** sp)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
   FinishCalleeSaveFrameSetup(self, sp, Runtime::kRefsOnly);
-  // Return value may hold Object* so avoid suspension.
-  const char* old_cause = self->StartAssertNoThreadSuspension("Deoptimizing stack frame");
-  CHECK(old_cause == NULL);
-  class DeoptimizationVisitor : public StackVisitor {
-   public:
-    DeoptimizationVisitor(Thread* thread, Context* context)
-        : StackVisitor(thread, context), shadow_frame_(NULL), runtime_frames_(0) { }
-
-    virtual bool VisitFrame() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
-      mirror::AbstractMethod* m = GetMethod();
-      if (m->IsRuntimeMethod()) {
-        if (runtime_frames_ == 0) {
-          runtime_frames_++;
-          return true;  // Skip the callee save frame.
-        } else {
-          return false;  // Caller was an upcall.
-        }
-      }
-      MethodHelper mh(m);
-      const DexFile::CodeItem* code_item = mh.GetCodeItem();
-      CHECK(code_item != NULL);
-      uint16_t num_regs =  code_item->registers_size_;
-      shadow_frame_ = ShadowFrame::Create(num_regs, NULL, m, GetDexPc());
-      std::vector<int32_t> kinds = DescribeVRegs(m->GetDexMethodIndex(), &mh.GetDexFile(),
-                                                 mh.GetDexCache(), mh.GetClassLoader(),
-                                                 mh.GetClassDefIndex(), code_item, m,
-                                                 m->GetAccessFlags(), GetDexPc());
-      for(uint16_t reg = 0; reg < num_regs; reg++) {
-        VRegKind kind = static_cast<VRegKind>(kinds.at(reg * 2));
-        switch (kind) {
-          case kUndefined:
-            shadow_frame_->SetVReg(reg, 0xEBADDE09);
-            break;
-          case kConstant:
-            shadow_frame_->SetVReg(reg, kinds.at((reg * 2) + 1));
-            break;
-          default:
-            shadow_frame_->SetVReg(reg, GetVReg(m, reg, kind));
-            break;
-        }
-      }
-      return false;  // Stop now we have built the shadow frame.
-    }
-
-    std::vector<int32_t> DescribeVRegs(uint32_t dex_method_idx,
-                                       const DexFile* dex_file,
-                                       mirror::DexCache* dex_cache,
-                                       mirror::ClassLoader* class_loader,
-                                       uint32_t class_def_idx,
-                                       const DexFile::CodeItem* code_item,
-                                       mirror::AbstractMethod* method,
-                                       uint32_t method_access_flags, uint32_t dex_pc)
-        SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
-      verifier::MethodVerifier verifier(dex_file, dex_cache, class_loader, class_def_idx, code_item,
-                                        dex_method_idx, method, method_access_flags, true);
-      verifier.Verify();
-      return verifier.DescribeVRegs(dex_pc);
-    }
-
-    ShadowFrame* shadow_frame_;
-    uint32_t runtime_frames_;
-  } visitor(self, self->GetLongJumpContext());
-  visitor.WalkStack(false);
-  if (visitor.shadow_frame_ != NULL) {
-    self->SetDeoptimizationShadowFrame(visitor.shadow_frame_, ret_val);
-    return (*sp)->GetFrameSizeInBytes();
-  } else {
-    return 0;  // Caller was an upcall.
-  }
-}
-
-
-extern "C" JValue artEnterInterpreterFromDeoptimize(Thread* self, mirror::AbstractMethod** sp)
-    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
-  FinishCalleeSaveFrameSetup(self, sp, Runtime::kRefsOnly);
-  JValue return_value;
-  UniquePtr<ShadowFrame> shadow_frame(self->GetAndClearDeoptimizationShadowFrame(&return_value));
-  self->EndAssertNoThreadSuspension(NULL);
-  return interpreter::EnterInterpreterFromDeoptimize(self, *shadow_frame.get(), return_value);
+  self->SetException(ThrowLocation(), reinterpret_cast<mirror::Throwable*>(-1));
+  self->QuickDeliverException();
 }
 
 }  // namespace art
diff --git a/src/oat/runtime/support_field.cc b/src/oat/runtime/support_field.cc
index 43d5c9b..5821063 100644
--- a/src/oat/runtime/support_field.cc
+++ b/src/oat/runtime/support_field.cc
@@ -86,7 +86,8 @@
   field = FindFieldFromCode(field_idx, referrer, self, InstancePrimitiveRead, sizeof(int32_t));
   if (LIKELY(field != NULL)) {
     if (UNLIKELY(obj == NULL)) {
-      ThrowNullPointerExceptionForFieldAccess(field, true);
+      ThrowLocation throw_location = self->GetCurrentLocationForThrow();
+      ThrowNullPointerExceptionForFieldAccess(throw_location, field, true);
     } else {
       return field->Get32(obj);
     }
@@ -106,7 +107,8 @@
   field = FindFieldFromCode(field_idx, referrer, self, InstancePrimitiveRead, sizeof(int64_t));
   if (LIKELY(field != NULL)) {
     if (UNLIKELY(obj == NULL)) {
-      ThrowNullPointerExceptionForFieldAccess(field, true);
+      ThrowLocation throw_location = self->GetCurrentLocationForThrow();
+      ThrowNullPointerExceptionForFieldAccess(throw_location, field, true);
     } else {
       return field->Get64(obj);
     }
@@ -127,7 +129,8 @@
   field = FindFieldFromCode(field_idx, referrer, self, InstanceObjectRead, sizeof(mirror::Object*));
   if (LIKELY(field != NULL)) {
     if (UNLIKELY(obj == NULL)) {
-      ThrowNullPointerExceptionForFieldAccess(field, true);
+      ThrowLocation throw_location = self->GetCurrentLocationForThrow();
+      ThrowNullPointerExceptionForFieldAccess(throw_location, field, true);
     } else {
       return field->GetObj(obj);
     }
@@ -204,7 +207,8 @@
   field = FindFieldFromCode(field_idx, referrer, self, InstancePrimitiveWrite, sizeof(int32_t));
   if (LIKELY(field != NULL)) {
     if (UNLIKELY(obj == NULL)) {
-      ThrowNullPointerExceptionForFieldAccess(field, false);
+      ThrowLocation throw_location = self->GetCurrentLocationForThrow();
+      ThrowNullPointerExceptionForFieldAccess(throw_location, field, false);
     } else {
       field->Set32(obj, new_value);
       return 0;  // success
@@ -230,7 +234,8 @@
   field = FindFieldFromCode(field_idx, referrer, self, InstancePrimitiveWrite, sizeof(int64_t));
   if (LIKELY(field != NULL)) {
     if (UNLIKELY(obj == NULL)) {
-      ThrowNullPointerExceptionForFieldAccess(field, false);
+      ThrowLocation throw_location = self->GetCurrentLocationForThrow();
+      ThrowNullPointerExceptionForFieldAccess(throw_location, field, false);
     } else {
       field->Set64(obj, new_value);
       return 0;  // success
@@ -255,7 +260,8 @@
                             sizeof(mirror::Object*));
   if (LIKELY(field != NULL)) {
     if (UNLIKELY(obj == NULL)) {
-      ThrowNullPointerExceptionForFieldAccess(field, false);
+      ThrowLocation throw_location = self->GetCurrentLocationForThrow();
+      ThrowNullPointerExceptionForFieldAccess(throw_location, field, false);
     } else {
       field->SetObj(obj, new_value);
       return 0;  // success
diff --git a/src/oat/runtime/support_fillarray.cc b/src/oat/runtime/support_fillarray.cc
index 73f832a..a0b06fb 100644
--- a/src/oat/runtime/support_fillarray.cc
+++ b/src/oat/runtime/support_fillarray.cc
@@ -15,6 +15,7 @@
  */
 
 #include "callee_save_frame.h"
+#include "common_throws.h"
 #include "dex_instruction.h"
 #include "mirror/array.h"
 #include "mirror/object-inl.h"
@@ -43,15 +44,15 @@
   FinishCalleeSaveFrameSetup(self, sp, Runtime::kRefsOnly);
   DCHECK_EQ(payload->ident, static_cast<uint16_t>(Instruction::kArrayDataSignature));
   if (UNLIKELY(array == NULL)) {
-    Thread::Current()->ThrowNewExceptionF("Ljava/lang/NullPointerException;",
-        "null array in FILL_ARRAY_DATA");
+    ThrowNullPointerException(NULL, "null array in FILL_ARRAY_DATA");
     return -1;  // Error
   }
   DCHECK(array->IsArrayInstance() && !array->IsObjectArray());
   if (UNLIKELY(static_cast<int32_t>(payload->element_count) > array->GetLength())) {
-    Thread::Current()->ThrowNewExceptionF("Ljava/lang/ArrayIndexOutOfBoundsException;",
-                                          "failed FILL_ARRAY_DATA; length=%d, index=%d",
-                                          array->GetLength(), payload->element_count);
+    ThrowLocation throw_location = self->GetCurrentLocationForThrow();
+    self->ThrowNewExceptionF(throw_location, "Ljava/lang/ArrayIndexOutOfBoundsException;",
+                             "failed FILL_ARRAY_DATA; length=%d, index=%d",
+                             array->GetLength(), payload->element_count);
     return -1;  // Error
   }
   uint32_t size_in_bytes = payload->element_count * payload->element_width;
diff --git a/src/oat/runtime/support_instrumentation.cc b/src/oat/runtime/support_instrumentation.cc
index 6598f19..8f56ce3 100644
--- a/src/oat/runtime/support_instrumentation.cc
+++ b/src/oat/runtime/support_instrumentation.cc
@@ -14,58 +14,51 @@
  * limitations under the License.
  */
 
-#include "base/logging.h"
+#include "callee_save_frame.h"
 #include "instrumentation.h"
+#include "mirror/abstract_method-inl.h"
+#include "mirror/object-inl.h"
 #include "runtime.h"
 #include "thread-inl.h"
-#include "trace.h"
 
 namespace art {
 
 extern "C" const void* artInstrumentationMethodEntryFromCode(mirror::AbstractMethod* method,
+                                                             mirror::Object* this_object,
                                                              Thread* self,
                                                              mirror::AbstractMethod** sp,
                                                              uintptr_t lr)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
-  self->SetTopOfStack(sp, lr);
-  self->VerifyStack();
-  Instrumentation* instrumentation = Runtime::Current()->GetInstrumentation();
-  // +1 as frame id's start at 1, +1 as we haven't yet built this method's frame.
-  size_t frame_id = StackVisitor::ComputeNumFrames(self) + 2;
-  InstrumentationStackFrame instrumentation_frame(method, lr, frame_id);
-  self->PushInstrumentationStackFrame(instrumentation_frame);
-
-  Trace* trace = instrumentation->GetTrace();
-  if (trace != NULL) {
-    trace->LogMethodTraceEvent(self, method, Trace::kMethodTraceEnter);
-  }
-
-  return instrumentation->GetSavedCodeFromMap(method);
+  FinishCalleeSaveFrameSetup(self, sp, Runtime::kRefsAndArgs);
+  instrumentation::Instrumentation* instrumentation = Runtime::Current()->GetInstrumentation();
+  instrumentation->PushInstrumentationStackFrame(self, method->IsStatic() ? NULL : this_object,
+                                                 method, lr);
+  const void* result = instrumentation->GetQuickCodeFor(method);
+  CHECK(result != NULL) << PrettyMethod(method);
+  return result;
 }
 
-extern "C" uint64_t artInstrumentationMethodExitFromCode(Thread* self, mirror::AbstractMethod** sp)
+extern "C" uint64_t artInstrumentationMethodExitFromCode(Thread* self, mirror::AbstractMethod** sp,
+                                                         uint64_t gpr_result, uint64_t fpr_result)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+  // TODO: use FinishCalleeSaveFrameSetup(self, sp, Runtime::kRefsOnly) not the hand inlined below.
+  //       We use the hand inline version to ensure the return_pc is assigned before verifying the
+  //       stack.
+  // Be aware the store below may well stomp on an incoming argument.
+  Locks::mutator_lock_->AssertSharedHeld(self);
+  mirror::AbstractMethod* callee_save = Runtime::Current()->GetCalleeSaveMethod(Runtime::kRefsOnly);
+  *sp = callee_save;
+  uintptr_t* return_pc = reinterpret_cast<uintptr_t*>(reinterpret_cast<byte*>(sp) +
+                                                      callee_save->GetReturnPcOffsetInBytes());
+  CHECK(*return_pc == 0);
   self->SetTopOfStack(sp, 0);
   self->VerifyStack();
-  // +1 as frame id's start at 1, +1 as we want the called frame not the frame being returned into.
-  size_t frame_id = StackVisitor::ComputeNumFrames(self) + 2;
-  InstrumentationStackFrame instrumentation_frame;
-  instrumentation_frame = self->PopInstrumentationStackFrame();
-  if (frame_id != instrumentation_frame.frame_id_) {
-    LOG(ERROR) << "Expected frame_id=" << frame_id << " but found " << instrumentation_frame.frame_id_;
-    StackVisitor::DescribeStack(self);
-  }
-  Runtime* runtime = Runtime::Current();
-  if (runtime->IsMethodTracingActive()) {
-    Trace* trace = runtime->GetInstrumentation()->GetTrace();
-    trace->LogMethodTraceEvent(self, instrumentation_frame.method_, Trace::kMethodTraceExit);
-  }
-  if (self->ReadFlag(kEnterInterpreter)) {
-    return static_cast<uint64_t>(GetDeoptimizationEntryPoint()) |
-        (static_cast<uint64_t>(instrumentation_frame.return_pc_) << 32);
-  } else {
-    return instrumentation_frame.return_pc_;
-  }
+  instrumentation::Instrumentation* instrumentation = Runtime::Current()->GetInstrumentation();
+  uint64_t return_or_deoptimize_pc = instrumentation->PopInstrumentationStackFrame(self, return_pc,
+                                                                                   gpr_result,
+                                                                                   fpr_result);
+  self->VerifyStack();
+  return return_or_deoptimize_pc;
 }
 
 }  // namespace art
diff --git a/src/oat/runtime/support_jni.cc b/src/oat/runtime/support_jni.cc
index ee19d4e..bc9cc45 100644
--- a/src/oat/runtime/support_jni.cc
+++ b/src/oat/runtime/support_jni.cc
@@ -33,7 +33,7 @@
   DCHECK(Thread::Current() == self);
   ScopedObjectAccess soa(self);
 
-  mirror::AbstractMethod* method = self->GetCurrentMethod();
+  mirror::AbstractMethod* method = self->GetCurrentMethod(NULL);
   DCHECK(method != NULL);
 
   // Lookup symbol address for method, on failure we'll return NULL with an
@@ -139,7 +139,7 @@
   // | unused |
   // | unused |
   // | unused | <- sp
-  mirror::AbstractMethod* jni_method = self->GetCurrentMethod();
+  mirror::AbstractMethod* jni_method = self->GetCurrentMethod(NULL);
   DCHECK(jni_method->IsNative()) << PrettyMethod(jni_method);
   intptr_t* arg_ptr = sp + 4;  // pointer to r1 on stack
   // Fix up this/jclass argument
diff --git a/src/oat/runtime/support_stubs.cc b/src/oat/runtime/support_stubs.cc
index 0cb3fe4..0e00dfd 100644
--- a/src/oat/runtime/support_stubs.cc
+++ b/src/oat/runtime/support_stubs.cc
@@ -242,7 +242,7 @@
     // go into deliver exception with the pending exception in r0
     CHECK(thread->IsExceptionPending());
     code = reinterpret_cast<void*>(art_quick_deliver_exception_from_code);
-    regs[0] = reinterpret_cast<uintptr_t>(thread->GetException());
+    regs[0] = reinterpret_cast<uintptr_t>(thread->GetException(NULL));
     thread->ClearException();
   } else {
     // Expect class to at least be initializing.
@@ -350,13 +350,14 @@
 
 #if !defined(ART_USE_PORTABLE_COMPILER)
 // Called by the AbstractMethodError. Called by stub code.
-extern void ThrowAbstractMethodErrorFromCode(mirror::AbstractMethod* method, Thread* thread,
+extern void ThrowAbstractMethodErrorFromCode(mirror::AbstractMethod* method, Thread* self,
                                              mirror::AbstractMethod** sp)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
-  FinishCalleeSaveFrameSetup(thread, sp, Runtime::kSaveAll);
-  thread->ThrowNewExceptionF("Ljava/lang/AbstractMethodError;",
-                             "abstract method \"%s\"", PrettyMethod(method).c_str());
-  thread->QuickDeliverException();
+  FinishCalleeSaveFrameSetup(self, sp, Runtime::kSaveAll);
+  ThrowLocation throw_location = self->GetCurrentLocationForThrow();
+  self->ThrowNewExceptionF(throw_location, "Ljava/lang/AbstractMethodError;",
+                           "abstract method \"%s\"", PrettyMethod(method).c_str());
+  self->QuickDeliverException();
 }
 #else // ART_USE_PORTABLE_COMPILER
 extern void ThrowAbstractMethodErrorFromCode(mirror::AbstractMethod* method, Thread* thread,
diff --git a/src/oat/runtime/support_throw.cc b/src/oat/runtime/support_throw.cc
index 80ba118..b8c68a5 100644
--- a/src/oat/runtime/support_throw.cc
+++ b/src/oat/runtime/support_throw.cc
@@ -23,14 +23,6 @@
 
 namespace art {
 
-// Used to implement MOVE_EXCEPTION.
-extern "C" void* GetAndClearException(Thread* self) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
-  DCHECK(self->IsExceptionPending());
-  mirror::Throwable* exception = self->GetException();
-  self->ClearException();
-  return exception;
-}
-
 // Deliver an exception that's pending on thread helping set up a callee save frame on the way.
 extern "C" void artDeliverPendingExceptionFromCode(Thread* thread, mirror::AbstractMethod** sp)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
@@ -39,7 +31,7 @@
 }
 
 // Called by generated call to throw an exception.
-extern "C" void artDeliverExceptionFromCode(mirror::Throwable* exception, Thread* thread,
+extern "C" void artDeliverExceptionFromCode(mirror::Throwable* exception, Thread* self,
                                             mirror::AbstractMethod** sp)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
   /*
@@ -49,9 +41,15 @@
    * and threw a NPE if NULL.  This routine responsible for setting
    * exception_ in thread and delivering the exception.
    */
-  FinishCalleeSaveFrameSetup(thread, sp, Runtime::kSaveAll);
-  thread->DeliverException(exception);
-  thread->QuickDeliverException();
+  FinishCalleeSaveFrameSetup(self, sp, Runtime::kSaveAll);
+  ThrowLocation throw_location = self->GetCurrentLocationForThrow();
+  if (exception == NULL) {
+    self->ThrowNewException(throw_location, "Ljava/lang/NullPointerException;",
+                            "throw with null exception");
+  } else {
+    self->SetException(throw_location, exception);
+  }
+  self->QuickDeliverException();
 }
 
 // Called by generated call to throw a NPE exception.
@@ -59,29 +57,27 @@
                                                      mirror::AbstractMethod** sp)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
   FinishCalleeSaveFrameSetup(self, sp, Runtime::kSaveAll);
-  uint32_t dex_pc;
-  mirror::AbstractMethod* throw_method = self->GetCurrentMethod(&dex_pc);
-  ThrowNullPointerExceptionFromDexPC(throw_method, dex_pc);
+  ThrowLocation throw_location = self->GetCurrentLocationForThrow();
+  ThrowNullPointerExceptionFromDexPC(throw_location);
   self->QuickDeliverException();
 }
 
 // Called by generated call to throw an arithmetic divide by zero exception.
-extern "C" void artThrowDivZeroFromCode(Thread* thread,
+extern "C" void artThrowDivZeroFromCode(Thread* self,
                                         mirror::AbstractMethod** sp)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
-  FinishCalleeSaveFrameSetup(thread, sp, Runtime::kSaveAll);
-  thread->ThrowNewException("Ljava/lang/ArithmeticException;", "divide by zero");
-  thread->QuickDeliverException();
+  FinishCalleeSaveFrameSetup(self, sp, Runtime::kSaveAll);
+  ThrowArithmeticExceptionDivideByZero(self);
+  self->QuickDeliverException();
 }
 
 // Called by generated call to throw an array index out of bounds exception.
-extern "C" void artThrowArrayBoundsFromCode(int index, int limit, Thread* thread,
+extern "C" void artThrowArrayBoundsFromCode(int index, int length, Thread* self,
                                             mirror::AbstractMethod** sp)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
-  FinishCalleeSaveFrameSetup(thread, sp, Runtime::kSaveAll);
-  thread->ThrowNewExceptionF("Ljava/lang/ArrayIndexOutOfBoundsException;",
-                             "length=%d; index=%d", limit, index);
-  thread->QuickDeliverException();
+  FinishCalleeSaveFrameSetup(self, sp, Runtime::kSaveAll);
+  ThrowArrayIndexOutOfBoundsException(index, length);
+  self->QuickDeliverException();
 }
 
 extern "C" void artThrowStackOverflowFromCode(Thread* self, mirror::AbstractMethod** sp)
@@ -95,8 +91,7 @@
                                              mirror::AbstractMethod** sp)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
   FinishCalleeSaveFrameSetup(self, sp, Runtime::kSaveAll);
-  mirror::AbstractMethod* method = self->GetCurrentMethod();
-  ThrowNoSuchMethodError(method_idx, method);
+  ThrowNoSuchMethodError(method_idx);
   self->QuickDeliverException();
 }
 
diff --git a/src/oat/runtime/x86/oat_support_entrypoints_x86.cc b/src/oat/runtime/x86/oat_support_entrypoints_x86.cc
index a7c518a..708e04e 100644
--- a/src/oat/runtime/x86/oat_support_entrypoints_x86.cc
+++ b/src/oat/runtime/x86/oat_support_entrypoints_x86.cc
@@ -33,10 +33,6 @@
 extern "C" void art_quick_can_put_array_element_from_code(void*, void*);
 extern "C" void art_quick_check_cast_from_code(void*, void*);
 
-// Debug entrypoints.
-extern void DebugMe(mirror::AbstractMethod* method, uint32_t info);
-extern "C" void art_quick_update_debugger(void*, void*, int32_t, void*);
-
 // DexCache entrypoints.
 extern "C" void* art_quick_initialize_static_storage_from_code(uint32_t, void*);
 extern "C" void* art_quick_initialize_type_from_code(uint32_t, void*);
@@ -130,10 +126,6 @@
   points->pCanPutArrayElementFromCode = art_quick_can_put_array_element_from_code;
   points->pCheckCastFromCode = art_quick_check_cast_from_code;
 
-  // Debug
-  points->pDebugMe = DebugMe;
-  points->pUpdateDebuggerFromCode = NULL; // Controlled by SetDebuggerUpdatesEnabled.
-
   // DexCache
   points->pInitializeStaticStorage = art_quick_initialize_static_storage_from_code;
   points->pInitializeTypeAndVerifyAccessFromCode = art_quick_initialize_type_and_verify_access_from_code;
@@ -220,10 +212,6 @@
   points->pThrowStackOverflowFromCode = art_quick_throw_stack_overflow_from_code;
 };
 
-void ChangeDebuggerEntryPoint(EntryPoints* points, bool enabled) {
-  points->pUpdateDebuggerFromCode = (enabled ? art_quick_update_debugger : NULL);
-}
-
 uintptr_t GetInstrumentationExitPc() {
   return reinterpret_cast<uintptr_t>(art_quick_instrumentation_exit_from_code);
 }
diff --git a/src/oat/runtime/x86/runtime_support_x86.S b/src/oat/runtime/x86/runtime_support_x86.S
index 4b4689f..4900b84 100644
--- a/src/oat/runtime/x86/runtime_support_x86.S
+++ b/src/oat/runtime/x86/runtime_support_x86.S
@@ -512,26 +512,6 @@
 TWO_ARG_DOWNCALL art_quick_initialize_type_from_code, artInitializeTypeFromCode, RETURN_IF_EAX_NOT_ZERO
 TWO_ARG_DOWNCALL art_quick_initialize_type_and_verify_access_from_code, artInitializeTypeAndVerifyAccessFromCode, RETURN_IF_EAX_NOT_ZERO
 
-    /*
-     * On entry, eax and ecx must be preserved, edx is dex PC
-     */
-DEFINE_FUNCTION art_quick_update_debugger
-    mov %eax, %ebx                // stash away eax so that it's saved as if it were an argument
-    SETUP_REF_AND_ARGS_CALLEE_SAVE_FRAME
-    subl LITERAL(4), %esp         // alignment padding
-    .cfi_adjust_cfa_offset 4
-    PUSH esp                      // pass arg2 (sp)
-    pushl %fs:THREAD_SELF_OFFSET  // pass Thread::Current()
-    .cfi_adjust_cfa_offset 4
-    PUSH edx                      // pass arg0 (dex pc)
-    call SYMBOL(artUpdateDebuggerFromCode) // artUpdateDebuggerFromCode(int32_t, Thread*, Method**)
-    addl LITERAL(16), %esp        // pop arguments
-    .cfi_adjust_cfa_offset -16
-    RESTORE_REF_AND_ARGS_CALLEE_SAVE_FRAME
-    mov %ebx, %eax                // restore original eax
-    ret
-END_FUNCTION art_quick_update_debugger
-
 ONE_ARG_DOWNCALL art_quick_lock_object_from_code, artLockObjectFromCode, ret
 ONE_ARG_DOWNCALL art_quick_unlock_object_from_code, artUnlockObjectFromCode, RETURN_IF_EAX_ZERO
 
@@ -879,6 +859,7 @@
     mov %esp, %ebx                // remember SP
     mov 32(%esp), %edx            // get referrer
     subl LITERAL(12), %esp        // alignment padding
+    .cfi_adjust_cfa_offset 12
     PUSH ebx                      // pass SP
     pushl %fs:THREAD_SELF_OFFSET  // pass Thread::Current()
     .cfi_adjust_cfa_offset 4
@@ -972,7 +953,7 @@
 END_FUNCTION art_quick_proxy_invoke_handler
 
 DEFINE_FUNCTION art_quick_interpreter_entry
-    SETUP_REF_AND_ARGS_CALLEE_SAVE_FRAME   // save frame and Method*
+    SETUP_REF_AND_ARGS_CALLEE_SAVE_FRAME   // save frame
     mov %esp, %edx                // remember SP
     PUSH eax                      // alignment padding
     PUSH edx                      // pass SP
@@ -992,71 +973,84 @@
      * Routine that intercepts method calls and returns.
      */
 DEFINE_FUNCTION art_quick_instrumentation_entry_from_code
-    xchgl %eax, (%esp)            // place LR in eax, save eax
-    PUSH ecx                      // save ecx
-    PUSH edx                      // save edx
-    PUSH ebx                      // save ebx
-    lea   16(%esp), %edx          // remember bottom of caller's frame
-    PUSH eax                      // pass LR
-    PUSH edx                      // pass SP
-    pushl %fs:THREAD_SELF_OFFSET  // pass Thread::Current()
+    SETUP_REF_AND_ARGS_CALLEE_SAVE_FRAME
+    movl  %esp, %edx              // Save SP.
+    PUSH eax                      // Save eax which will be clobbered by the callee-save method.
+    subl LITERAL(8), %esp         // Align stack.
+    .cfi_adjust_cfa_offset 8
+    pushl 40(%esp)                // Pass LR.
     .cfi_adjust_cfa_offset 4
-    pushl 24(%esp)                // pass Method*
+    PUSH edx                      // Pass SP.
+    pushl %fs:THREAD_SELF_OFFSET  // Pass Thread::Current().
     .cfi_adjust_cfa_offset 4
-    call  SYMBOL(artInstrumentationMethodEntryFromCode) // (Method*, Thread*, SP, LR)
-    addl  LITERAL(16), %esp       // pop arguments
-    POP ebx                       // restore ebx
-    POP edx                       // restore edx
-    movl  (%esp), %ecx            // restore ecx (without popping)
-    movl  %eax, (%esp)            // place method's code pointer on stack
-    movl  4(%esp), %eax           // restore eax (without popping)
-    movl  LITERAL(SYMBOL(art_quick_instrumentation_exit_from_code)), 4(%esp)
-                                  // place instrumentation exit as return pc
-    ret                           // call method (and pop)
+    PUSH ecx                      // Pass receiver.
+    PUSH eax                      // Pass Method*.
+    call  SYMBOL(artInstrumentationMethodEntryFromCode) // (Method*, Object*, Thread*, SP, LR)
+    addl  LITERAL(28), %esp       // Pop arguments upto saved Method*.
+    movl 28(%esp), %edi           // Restore edi.
+    movl %eax, 28(%esp)           // Place code* over edi, just under return pc.
+    movl LITERAL(SYMBOL(art_quick_instrumentation_exit_from_code)), 32(%esp)
+                                  // Place instrumentation exit as return pc.
+    movl (%esp), %eax             // Restore eax.
+    movl 8(%esp), %ecx            // Restore ecx.
+    movl 12(%esp), %edx           // Restore edx.
+    movl 16(%esp), %ebx           // Restore ebx.
+    movl 20(%esp), %ebp           // Restore ebp.
+    movl 24(%esp), %esi           // Restore esi.
+    addl LITERAL(28), %esp        // Wind stack back upto code*.
+    ret                           // Call method (and pop).
 END_FUNCTION art_quick_instrumentation_entry_from_code
+
 DEFINE_FUNCTION art_quick_instrumentation_exit_from_code
-    mov   %esp, %ecx              // remember bottom of caller's frame
-    PUSH edx                      // save return value
-    PUSH eax                      // save other half of return value
-    PUSH ecx                      // pass SP
-    pushl %fs:THREAD_SELF_OFFSET  // pass Thread::Current
+    pushl LITERAL(0)              // Push a fake return PC as there will be none on the stack.
+    SETUP_REF_ONLY_CALLEE_SAVE_FRAME
+    mov  %esp, %ecx               // Remember SP
+    subl LITERAL(8), %esp         // Save float return value.
+    .cfi_adjust_cfa_offset 8
+    movd %xmm0, (%esp)
+    PUSH edx                      // Save gpr return value.
+    PUSH eax
+    subl LITERAL(8), %esp         // Align stack
+    movd %xmm0, (%esp)
+    subl LITERAL(8), %esp         // Pass float return value.
+    .cfi_adjust_cfa_offset 8
+    movd %xmm0, (%esp)
+    PUSH edx                      // Pass gpr return value.
+    PUSH eax
+    PUSH ecx                      // Pass SP.
+    pushl %fs:THREAD_SELF_OFFSET  // Pass Thread::Current.
     .cfi_adjust_cfa_offset 4
-    call  SYMBOL(artInstrumentationMethodExitFromCode)  // (Thread*, SP)
-    mov   %eax, %ecx              // move returned link register
-    // TODO: Set link register for deopt
-    addl LITERAL(8), %esp         // pop arguments
+    call  SYMBOL(artInstrumentationMethodExitFromCode)  // (Thread*, SP, gpr_result, fpr_result)
+    mov   %eax, %ecx              // Move returned link register.
+    addl LITERAL(32), %esp        // Pop arguments.
+    .cfi_adjust_cfa_offset -32
+    movl %edx, %ebx               // Move returned link register for deopt
+                                  // (ebx is pretending to be our LR).
+    POP eax                       // Restore gpr return value.
+    POP edx
+    movd (%esp), %xmm0            // Restore fpr return value.
+    addl LITERAL(8), %esp
     .cfi_adjust_cfa_offset -8
-    POP eax                       // restore return value
-    POP edx                       // restore other half of return value
-    jmp   *%ecx                   // return
+    RESTORE_REF_ONLY_CALLEE_SAVE_FRAME
+    addl LITERAL(4), %esp         // Remove fake return pc.
+    jmp   *%ecx                   // Return.
 END_FUNCTION art_quick_instrumentation_exit_from_code
 
     /*
-     * The thread's enter interpreter flag is set and so we should transition to the interpreter
-     * rather than allow execution to continue in the frame below. There may be live results in
-     * registers depending on how complete the operation is when we safepoint - for example, a
-     * set operation may have completed while a get operation needs writing back into the vregs.
+     * Instrumentation has requested that we deoptimize into the interpreter. The deoptimization
+     * will long jump to the upcall with a special exception of -1.
      */
 DEFINE_FUNCTION art_quick_deoptimize
+    pushl %ebx                    // Fake that we were called.
     SETUP_REF_ONLY_CALLEE_SAVE_FRAME
-    PUSH esp                      // pass SP
-    pushl %fs:THREAD_SELF_OFFSET  // pass Thread::Current()
+    mov  %esp, %ecx               // Remember SP.
+    subl LITERAL(8), %esp         // Align stack.
+    .cfi_adjust_cfa_offset 8
+    PUSH ecx                      // Pass SP.
+    pushl %fs:THREAD_SELF_OFFSET  // Pass Thread::Current().
     .cfi_adjust_cfa_offset 4
-    PUSH edx                      // push half of return value
-    PUSH eax                      // push other half of return value
-    call SYMBOL(artDeoptimize)    // artDeoptimize(return value, Thread*, SP)
-                                  // Returns caller method's frame size.
-    addl LITERAL(16), %esp        // pop arguments
-    RESTORE_REF_ONLY_CALLEE_SAVE_FRAME
-    testl %eax, %eax              // Was the caller an upcall?
-    jz    1f                      // Return if caller was upcall.
-    lea   (%esp, %eax), %edx      // edx == bottom of caller's frame.
-    mov   %edx, %esp              // Remove frame.
-    SETUP_REF_ONLY_CALLEE_SAVE_FRAME
-    call SYMBOL(artEnterInterpreterFromDeoptimize) // Enter interpreter, callee-save ends stack fragment.
-    RESTORE_REF_ONLY_CALLEE_SAVE_FRAME
-1:
-    ret                           // Return to caller.
+    call SYMBOL(artDeoptimize)    // artDeoptimize(Thread*, SP)
+    int3                          // Unreachable.
 END_FUNCTION art_quick_deoptimize
 
     /*
diff --git a/src/reflection.cc b/src/reflection.cc
index 73a8a53..467575c 100644
--- a/src/reflection.cc
+++ b/src/reflection.cc
@@ -17,6 +17,7 @@
 #include "reflection.h"
 
 #include "class_linker.h"
+#include "common_throws.h"
 #include "dex_file-inl.h"
 #include "invoke_arg_array_builder.h"
 #include "jni_internal.h"
@@ -64,9 +65,9 @@
   uint32_t classes_size = classes == NULL ? 0 : classes->Size();
   uint32_t arg_count = (objects != NULL) ? objects->GetLength() : 0;
   if (arg_count != classes_size) {
-    soa.Self()->ThrowNewExceptionF("Ljava/lang/IllegalArgumentException;",
-        "wrong number of arguments; expected %d, got %d",
-        classes_size, arg_count);
+    ThrowIllegalArgumentException(NULL,
+                                  StringPrintf("Wrong number of arguments; expected %d, got %d",
+                                               classes_size, arg_count).c_str());
     return NULL;
   }
 
@@ -103,23 +104,23 @@
 }
 
 bool VerifyObjectInClass(mirror::Object* o, mirror::Class* c) {
-  const char* exception = NULL;
   if (o == NULL) {
-    exception = "Ljava/lang/NullPointerException;";
+    ThrowNullPointerException(NULL, "null receiver");
+    return false;
   } else if (!o->InstanceOf(c)) {
-    exception = "Ljava/lang/IllegalArgumentException;";
-  }
-  if (exception != NULL) {
     std::string expected_class_name(PrettyDescriptor(c));
     std::string actual_class_name(PrettyTypeOf(o));
-    Thread::Current()->ThrowNewExceptionF(exception, "expected receiver of type %s, but got %s",
-                                          expected_class_name.c_str(), actual_class_name.c_str());
+    ThrowIllegalArgumentException(NULL,
+                                  StringPrintf("Expected receiver of type %s, but got %s",
+                                               expected_class_name.c_str(),
+                                               actual_class_name.c_str()).c_str());
     return false;
   }
   return true;
 }
 
-bool ConvertPrimitiveValue(Primitive::Type srcType, Primitive::Type dstType,
+bool ConvertPrimitiveValue(const ThrowLocation* throw_location, bool unbox_for_result,
+                           Primitive::Type srcType, Primitive::Type dstType,
                            const JValue& src, JValue& dst) {
   CHECK(srcType != Primitive::kPrimNot && dstType != Primitive::kPrimNot);
   switch (dstType) {
@@ -196,10 +197,18 @@
   default:
     break;
   }
-  Thread::Current()->ThrowNewExceptionF("Ljava/lang/IllegalArgumentException;",
-                                        "invalid primitive conversion from %s to %s",
-                                        PrettyDescriptor(srcType).c_str(),
-                                        PrettyDescriptor(dstType).c_str());
+  if (!unbox_for_result) {
+    ThrowIllegalArgumentException(throw_location,
+                                  StringPrintf("Invalid primitive conversion from %s to %s",
+                                               PrettyDescriptor(srcType).c_str(),
+                                               PrettyDescriptor(dstType).c_str()).c_str());
+  } else {
+    ThrowClassCastException(throw_location,
+                            StringPrintf("Couldn't convert result of type %s to %s",
+                                         PrettyDescriptor(srcType).c_str(),
+                                         PrettyDescriptor(dstType).c_str()
+                                         ).c_str());
+  }
   return false;
 }
 
@@ -271,32 +280,48 @@
   return "result";
 }
 
-static bool UnboxPrimitive(mirror::Object* o, mirror::Class* dst_class, JValue& unboxed_value,
+static bool UnboxPrimitive(const ThrowLocation* throw_location, mirror::Object* o,
+                           mirror::Class* dst_class, JValue& unboxed_value,
                            mirror::AbstractMethod* m, int index, mirror::Field* f)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+  bool unbox_for_result = (f == NULL) && (index == -1);
   if (!dst_class->IsPrimitive()) {
-    if (o != NULL && !o->InstanceOf(dst_class)) {
-      Thread::Current()->ThrowNewExceptionF("Ljava/lang/IllegalArgumentException;",
-                                            "%s has type %s, got %s",
-                                            UnboxingFailureKind(m, index, f).c_str(),
-                                            PrettyDescriptor(dst_class).c_str(),
-                                            PrettyTypeOf(o).c_str());
+    if (UNLIKELY(o != NULL && !o->InstanceOf(dst_class))) {
+      if (!unbox_for_result) {
+        ThrowIllegalArgumentException(throw_location,
+                                      StringPrintf("%s has type %s, got %s",
+                                                   UnboxingFailureKind(m, index, f).c_str(),
+                                                   PrettyDescriptor(dst_class).c_str(),
+                                                   PrettyTypeOf(o).c_str()).c_str());
+      } else {
+        ThrowClassCastException(throw_location,
+                                StringPrintf("Couldn't convert result of type %s to %s",
+                                             PrettyTypeOf(o).c_str(),
+                                             PrettyDescriptor(dst_class).c_str()
+                                             ).c_str());
+      }
       return false;
     }
     unboxed_value.SetL(o);
     return true;
-  } else if (dst_class->GetPrimitiveType() == Primitive::kPrimVoid) {
-    Thread::Current()->ThrowNewExceptionF("Ljava/lang/IllegalArgumentException;",
-                                          "can't unbox %s to void",
-                                          UnboxingFailureKind(m, index, f).c_str());
+  }
+  if (UNLIKELY(dst_class->GetPrimitiveType() == Primitive::kPrimVoid)) {
+    ThrowIllegalArgumentException(throw_location,
+                                  StringPrintf("Can't unbox %s to void",
+                                               UnboxingFailureKind(m, index, f).c_str()).c_str());
     return false;
   }
-
-  if (o == NULL) {
-    Thread::Current()->ThrowNewExceptionF("Ljava/lang/IllegalArgumentException;",
-                                          "%s has type %s, got null",
-                                          UnboxingFailureKind(m, index, f).c_str(),
-                                          PrettyDescriptor(dst_class).c_str());
+  if (UNLIKELY(o == NULL)) {
+    if (!unbox_for_result) {
+      ThrowIllegalArgumentException(throw_location,
+                                    StringPrintf("%s has type %s, got null",
+                                                 UnboxingFailureKind(m, index, f).c_str(),
+                                                 PrettyDescriptor(dst_class).c_str()).c_str());
+    } else {
+      ThrowNullPointerException(throw_location,
+                                StringPrintf("Expected to unbox a '%s' primitive type but was returned null",
+                                             PrettyDescriptor(dst_class).c_str()).c_str());
+    }
     return false;
   }
 
@@ -330,32 +355,35 @@
     src_class = class_linker->FindPrimitiveClass('S');
     boxed_value.SetS(primitive_field->GetShort(o));
   } else {
-    Thread::Current()->ThrowNewExceptionF("Ljava/lang/IllegalArgumentException;",
-                                          "%s has type %s, got %s",
-                                          UnboxingFailureKind(m, index, f).c_str(),
-                                          PrettyDescriptor(dst_class).c_str(),
-                                          PrettyDescriptor(src_descriptor.c_str()).c_str());
+    ThrowIllegalArgumentException(throw_location,
+                                  StringPrintf("%s has type %s, got %s",
+                                               UnboxingFailureKind(m, index, f).c_str(),
+                                               PrettyDescriptor(dst_class).c_str(),
+                                               PrettyDescriptor(src_descriptor.c_str()).c_str()
+                                               ).c_str());
     return false;
   }
 
-  return ConvertPrimitiveValue(src_class->GetPrimitiveType(), dst_class->GetPrimitiveType(),
+  return ConvertPrimitiveValue(throw_location, unbox_for_result,
+                               src_class->GetPrimitiveType(), dst_class->GetPrimitiveType(),
                                boxed_value, unboxed_value);
 }
 
 bool UnboxPrimitiveForArgument(mirror::Object* o, mirror::Class* dst_class, JValue& unboxed_value,
                                mirror::AbstractMethod* m, size_t index) {
   CHECK(m != NULL);
-  return UnboxPrimitive(o, dst_class, unboxed_value, m, index, NULL);
+  return UnboxPrimitive(NULL, o, dst_class, unboxed_value, m, index, NULL);
 }
 
 bool UnboxPrimitiveForField(mirror::Object* o, mirror::Class* dst_class, JValue& unboxed_value,
                             mirror::Field* f) {
   CHECK(f != NULL);
-  return UnboxPrimitive(o, dst_class, unboxed_value, NULL, -1, f);
+  return UnboxPrimitive(NULL, o, dst_class, unboxed_value, NULL, -1, f);
 }
 
-bool UnboxPrimitiveForResult(mirror::Object* o, mirror::Class* dst_class, JValue& unboxed_value) {
-  return UnboxPrimitive(o, dst_class, unboxed_value, NULL, -1, NULL);
+bool UnboxPrimitiveForResult(const ThrowLocation& throw_location, mirror::Object* o,
+                             mirror::Class* dst_class, JValue& unboxed_value) {
+  return UnboxPrimitive(&throw_location, o, dst_class, unboxed_value, NULL, -1, NULL);
 }
 
 }  // namespace art
diff --git a/src/reflection.h b/src/reflection.h
index 8f32243..e9f4e08 100644
--- a/src/reflection.h
+++ b/src/reflection.h
@@ -29,6 +29,7 @@
 }  // namespace mirror
 union JValue;
 class ScopedObjectAccess;
+class ThrowLocation;
 
 mirror::Object* BoxPrimitive(Primitive::Type src_class, const JValue& value)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
@@ -38,11 +39,13 @@
 bool UnboxPrimitiveForField(mirror::Object* o, mirror::Class* dst_class, JValue& unboxed_value,
                             mirror::Field* f)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
-bool UnboxPrimitiveForResult(mirror::Object* o, mirror::Class* dst_class, JValue& unboxed_value)
+bool UnboxPrimitiveForResult(const ThrowLocation& throw_location, mirror::Object* o,
+                             mirror::Class* dst_class, JValue& unboxed_value)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
-bool ConvertPrimitiveValue(Primitive::Type src_class, Primitive::Type dst_class, const JValue& src,
-                           JValue& dst)
+bool ConvertPrimitiveValue(const ThrowLocation* throw_location, bool unbox_for_result,
+                           Primitive::Type src_class, Primitive::Type dst_class,
+                           const JValue& src, JValue& dst)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
 jobject InvokeMethod(const ScopedObjectAccess& soa, jobject method, jobject receiver, jobject args)
diff --git a/src/runtime.cc b/src/runtime.cc
index 3e9cd8e..23a7309 100644
--- a/src/runtime.cc
+++ b/src/runtime.cc
@@ -43,6 +43,7 @@
 #include "jni_internal.h"
 #include "mirror/abstract_method-inl.h"
 #include "mirror/array.h"
+#include "mirror/class-inl.h"
 #include "mirror/class_loader.h"
 #include "mirror/field.h"
 #include "mirror/field-inl.h"
@@ -97,7 +98,7 @@
       stats_enabled_(false),
       method_trace_(0),
       method_trace_file_size_(0),
-      instrumentation_(NULL),
+      instrumentation_(),
       use_compile_time_class_path_(false),
       main_thread_group_(NULL),
       system_thread_group_(NULL) {
@@ -119,11 +120,7 @@
     }
     shutting_down_ = true;
   }
-
-  if (IsMethodTracingActive()) {
-    Trace::Shutdown();
-  }
-  delete instrumentation_;
+  Trace::Shutdown();
 
   // Make sure to let the GC complete if it is running.
   heap_->WaitForConcurrentGcToComplete(self);
@@ -171,8 +168,11 @@
       os << "Aborting thread:\n";
       self->Dump(os);
       if (self->IsExceptionPending()) {
-        os << "Pending " << PrettyTypeOf(self->GetException()) << " on thread:\n"
-           << self->GetException()->Dump();
+        ThrowLocation throw_location;
+        mirror::Throwable* exception = self->GetException(&throw_location);
+        os << "Pending exception " << PrettyTypeOf(exception)
+            << " thrown by '" << throw_location.Dump() << "\n"
+            << exception->Dump();
       }
     }
     DumpAllThreads(os, self);
@@ -652,9 +652,9 @@
 
   // Pre-allocate an OutOfMemoryError for the double-OOME case.
   Thread* self = Thread::Current();
-  self->ThrowNewException("Ljava/lang/OutOfMemoryError;",
+  self->ThrowNewException(ThrowLocation(), "Ljava/lang/OutOfMemoryError;",
                           "OutOfMemoryError thrown while trying to throw OutOfMemoryError; no stack available");
-  pre_allocated_OutOfMemoryError_ = self->GetException();
+  pre_allocated_OutOfMemoryError_ = self->GetException(NULL);
   self->ClearException();
 
   // Restore main thread state to kNative as expected by native code.
@@ -794,7 +794,6 @@
 
   is_compiler_ = options->is_compiler_;
   is_zygote_ = options->is_zygote_;
-  interpreter_only_ = options->interpreter_only_;
   is_concurrent_gc_enabled_ = options->is_concurrent_gc_enabled_;
 
   vfprintf_ = options->hook_vfprintf_;
@@ -809,6 +808,10 @@
   intern_table_ = new InternTable;
 
 
+  if (options->interpreter_only_) {
+    GetInstrumentation()->ForceInterpretOnly();
+  }
+
   heap_ = new Heap(options->heap_initial_size_,
                    options->heap_growth_limit_,
                    options->heap_min_free_,
@@ -1196,28 +1199,6 @@
   callee_save_methods_[type] = method;
 }
 
-void Runtime::EnableMethodTracing(Trace* trace) {
-  CHECK(!IsMethodTracingActive());
-  if (instrumentation_ == NULL) {
-    instrumentation_ = new Instrumentation();
-  }
-  instrumentation_->SetTrace(trace);
-}
-
-void Runtime::DisableMethodTracing() {
-  CHECK(IsMethodTracingActive());
-  instrumentation_->RemoveTrace();
-}
-
-bool Runtime::IsMethodTracingActive() const {
-  return instrumentation_ != NULL && instrumentation_->GetTrace() != NULL;
-}
-
-Instrumentation* Runtime::GetInstrumentation() const {
-  CHECK(IsMethodTracingActive());
-  return instrumentation_;
-}
-
 const std::vector<const DexFile*>& Runtime::GetCompileTimeClassPath(jobject class_loader) {
   if (class_loader == NULL) {
     return GetClassLinker()->GetBootClassPath();
diff --git a/src/runtime.h b/src/runtime.h
index f8788ad..67c8e36 100644
--- a/src/runtime.h
+++ b/src/runtime.h
@@ -30,6 +30,7 @@
 #include "globals.h"
 #include "heap.h"
 #include "instruction_set.h"
+#include "instrumentation.h"
 #include "jobject_comparator.h"
 #include "locks.h"
 #include "root_visitor.h"
@@ -49,7 +50,6 @@
 class ClassLinker;
 class DexFile;
 class Heap;
-class Instrumentation;
 class InternTable;
 struct JavaVMExt;
 class MonitorList;
@@ -112,10 +112,6 @@
     return is_zygote_;
   }
 
-  bool InterpreterOnly() const {
-    return interpreter_only_;
-  }
-
   bool IsConcurrentGcEnabled() const {
     return is_concurrent_gc_enabled_;
   }
@@ -234,8 +230,7 @@
   void DirtyRoots();
 
   // Visit all the roots.
-  void VisitRoots(RootVisitor* visitor, void* arg)
-      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+  void VisitRoots(RootVisitor* visitor, void* arg) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
   // Visit all of the roots we can do safely do concurrently.
   void VisitConcurrentRoots(RootVisitor* visitor, void* arg);
@@ -350,10 +345,9 @@
   bool InitZygote();
   void DidForkFromZygote();
 
-  void EnableMethodTracing(Trace* trace);
-  void DisableMethodTracing();
-  bool IsMethodTracingActive() const;
-  Instrumentation* GetInstrumentation() const;
+  instrumentation::Instrumentation* GetInstrumentation() {
+    return &instrumentation_;
+  }
 
   bool UseCompileTimeClassPath() const {
     return use_compile_time_class_path_;
@@ -383,7 +377,6 @@
 
   bool is_compiler_;
   bool is_zygote_;
-  bool interpreter_only_;
   bool is_concurrent_gc_enabled_;
 
   // The host prefix is used during cross compilation. It is removed
@@ -466,7 +459,7 @@
   bool method_trace_;
   std::string method_trace_file_;
   size_t method_trace_file_size_;
-  Instrumentation* instrumentation_;
+  instrumentation::Instrumentation instrumentation_;
 
   typedef SafeMap<jobject, std::vector<const DexFile*>, JobjectComparator> CompileTimeClassPaths;
   CompileTimeClassPaths compile_time_class_paths_;
diff --git a/src/runtime_support.cc b/src/runtime_support.cc
index 5b2c58c..b601f8c 100644
--- a/src/runtime_support.cc
+++ b/src/runtime_support.cc
@@ -101,16 +101,16 @@
 namespace art {
 
 // Helper function to allocate array for FILLED_NEW_ARRAY.
-mirror::Array* CheckAndAllocArrayFromCode(uint32_t type_idx, mirror::AbstractMethod* method,
+mirror::Array* CheckAndAllocArrayFromCode(uint32_t type_idx, mirror::AbstractMethod* referrer,
                                           int32_t component_count, Thread* self,
                                           bool access_check) {
   if (UNLIKELY(component_count < 0)) {
-    self->ThrowNewExceptionF("Ljava/lang/NegativeArraySizeException;", "%d", component_count);
+    ThrowNegativeArraySizeException(component_count);
     return NULL;  // Failure
   }
-  mirror::Class* klass = method->GetDexCacheResolvedTypes()->Get(type_idx);
+  mirror::Class* klass = referrer->GetDexCacheResolvedTypes()->Get(type_idx);
   if (UNLIKELY(klass == NULL)) {  // Not in dex cache so try to resolve
-    klass = Runtime::Current()->GetClassLinker()->ResolveType(type_idx, method);
+    klass = Runtime::Current()->GetClassLinker()->ResolveType(type_idx, referrer);
     if (klass == NULL) {  // Error
       DCHECK(self->IsExceptionPending());
       return NULL;  // Failure
@@ -118,20 +118,21 @@
   }
   if (UNLIKELY(klass->IsPrimitive() && !klass->IsPrimitiveInt())) {
     if (klass->IsPrimitiveLong() || klass->IsPrimitiveDouble()) {
-      self->ThrowNewExceptionF("Ljava/lang/RuntimeException;",
-                               "Bad filled array request for type %s",
-                                PrettyDescriptor(klass).c_str());
+      ThrowRuntimeException("Bad filled array request for type %s",
+                            PrettyDescriptor(klass).c_str());
     } else {
-      self->ThrowNewExceptionF("Ljava/lang/InternalError;",
+      ThrowLocation throw_location = self->GetCurrentLocationForThrow();
+      DCHECK(throw_location.GetMethod() == referrer);
+      self->ThrowNewExceptionF(throw_location, "Ljava/lang/InternalError;",
                                "Found type %s; filled-new-array not implemented for anything but \'int\'",
                                PrettyDescriptor(klass).c_str());
     }
     return NULL;  // Failure
   } else {
     if (access_check) {
-      mirror::Class* referrer = method->GetDeclaringClass();
-      if (UNLIKELY(!referrer->CanAccess(klass))) {
-        ThrowIllegalAccessErrorClass(referrer, klass);
+      mirror::Class* referrer_klass = referrer->GetDeclaringClass();
+      if (UNLIKELY(!referrer_klass->CanAccess(klass))) {
+        ThrowIllegalAccessErrorClass(referrer_klass, klass);
         return NULL;  // Failure
       }
     }
@@ -194,7 +195,9 @@
       FieldHelper fh(resolved_field);
       if (UNLIKELY(fh.IsPrimitiveType() != is_primitive ||
                    fh.FieldSize() != expected_size)) {
-        self->ThrowNewExceptionF("Ljava/lang/NoSuchFieldError;",
+        ThrowLocation throw_location = self->GetCurrentLocationForThrow();
+        DCHECK(throw_location.GetMethod() == referrer);
+        self->ThrowNewExceptionF(throw_location, "Ljava/lang/NoSuchFieldError;",
                                  "Attempted read of %zd-bit %s on field '%s'",
                                  expected_size * (32 / sizeof(int32_t)),
                                  is_primitive ? "primitive" : "non-primitive",
@@ -232,7 +235,9 @@
   } else if (UNLIKELY(this_object == NULL && type != kStatic)) {
     // Maintain interpreter-like semantics where NullPointerException is thrown
     // after potential NoSuchMethodError from class linker.
-    ThrowNullPointerExceptionForMethodAccess(referrer, method_idx, type);
+    ThrowLocation throw_location = self->GetCurrentLocationForThrow();
+    DCHECK(referrer == throw_location.GetMethod());
+    ThrowNullPointerExceptionForMethodAccess(throw_location, method_idx, type);
     return NULL;  // Failure.
   } else {
     if (!access_check) {
@@ -320,7 +325,7 @@
           // Behavior to agree with that of the verifier.
           MethodHelper mh(resolved_method);
           ThrowNoSuchMethodError(type, resolved_method->GetDeclaringClass(), mh.GetName(),
-                                 mh.GetSignature(), referrer);
+                                 mh.GetSignature());
           return NULL;  // Failure.
         }
       }
@@ -363,10 +368,12 @@
 
 void ThrowStackOverflowError(Thread* self) {
   CHECK(!self->IsHandlingStackOverflow()) << "Recursive stack overflow.";
-  // Remove extra entry pushed onto second stack during method tracing.
-  if (Runtime::Current()->IsMethodTracingActive()) {
-    InstrumentationMethodUnwindFromCode(self);
+
+  if (Runtime::Current()->GetInstrumentation()->AreExitStubsInstalled()) {
+    // Remove extra entry pushed onto second stack during method tracing.
+    Runtime::Current()->GetInstrumentation()->PopMethodForUnwind(self, false);
   }
+
   self->SetStackEndForStackOverflow();  // Allow space on the stack for constructor to execute.
   JNIEnvExt* env = self->GetJniEnv();
   std::string msg("stack size ");
@@ -430,33 +437,36 @@
                                    invocation_args);
 
   // Unbox result and handle error conditions.
-  if (!soa.Self()->IsExceptionPending()) {
-    if (shorty[0] == 'V' || result == NULL) {
+  if (LIKELY(!soa.Self()->IsExceptionPending())) {
+    if (shorty[0] == 'V' || (shorty[0] == 'L' && result == NULL)) {
       // Do nothing.
       return zero;
     } else {
-      JValue result_unboxed;
-      MethodHelper mh(soa.Decode<mirror::AbstractMethod*>(interface_method_jobj));
-      mirror::Class* result_type = mh.GetReturnType();
       mirror::Object* result_ref = soa.Decode<mirror::Object*>(result);
-      bool unboxed_okay = UnboxPrimitiveForResult(result_ref, result_type, result_unboxed);
-      if (!unboxed_okay) {
-        // UnboxPrimitiveForResult creates an IllegalArgumentException. Discard and create a
-        // meaningful ClassCastException.
+      mirror::Object* rcvr = soa.Decode<mirror::Object*>(rcvr_jobj);
+      mirror::AbstractMethod* interface_method =
+          soa.Decode<mirror::AbstractMethod*>(interface_method_jobj);
+      mirror::Class* result_type = MethodHelper(interface_method).GetReturnType();
+      mirror::AbstractMethod* proxy_method;
+      if (interface_method->GetDeclaringClass()->IsInterface()) {
+        proxy_method = rcvr->GetClass()->FindVirtualMethodForInterface(interface_method);
+      } else {
+        // Proxy dispatch to a method defined in Object.
+        DCHECK(interface_method->GetDeclaringClass()->IsObjectClass());
+        proxy_method = interface_method;
+      }
+      ThrowLocation throw_location(rcvr, proxy_method, -1);
+      JValue result_unboxed;
+      if (!UnboxPrimitiveForResult(throw_location, result_ref, result_type, result_unboxed)) {
         DCHECK(soa.Self()->IsExceptionPending());
-        soa.Self()->ClearException();
-        soa.Self()->ThrowNewException("Ljava/lang/ClassCastException;",
-                                      StringPrintf("Couldn't convert result of type %s to %s",
-                                                   PrettyTypeOf(result_ref).c_str(),
-                                                   PrettyDescriptor(result_type).c_str()
-                                      ).c_str());
+        return zero;
       }
       return result_unboxed;
     }
   } else {
     // In the case of checked exceptions that aren't declared, the exception must be wrapped by
     // a UndeclaredThrowableException.
-    mirror::Throwable* exception = soa.Self()->GetException();
+    mirror::Throwable* exception = soa.Self()->GetException(NULL);
     if (exception->IsCheckedException()) {
       mirror::Object* rcvr = soa.Decode<mirror::Object*>(rcvr_jobj);
       mirror::SynthesizedProxyClass* proxy_class =
@@ -482,7 +492,9 @@
         declares_exception = declared_exception->IsAssignableFrom(exception_class);
       }
       if (!declares_exception) {
-        soa.Self()->ThrowNewWrappedException("Ljava/lang/reflect/UndeclaredThrowableException;",
+        ThrowLocation throw_location(rcvr, proxy_method, -1);
+        soa.Self()->ThrowNewWrappedException(throw_location,
+                                             "Ljava/lang/reflect/UndeclaredThrowableException;",
                                              NULL);
       }
     }
diff --git a/src/runtime_support.h b/src/runtime_support.h
index 89026c1..c7eb957 100644
--- a/src/runtime_support.h
+++ b/src/runtime_support.h
@@ -68,7 +68,8 @@
   }
   if (access_check) {
     if (UNLIKELY(!klass->IsInstantiable())) {
-      self->ThrowNewException("Ljava/lang/InstantiationError;",
+      ThrowLocation throw_location = self->GetCurrentLocationForThrow();
+      self->ThrowNewException(throw_location, "Ljava/lang/InstantiationError;",
                               PrettyDescriptor(klass).c_str());
       return NULL;  // Failure
     }
@@ -95,7 +96,7 @@
                                                 Thread* self, bool access_check)
     SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
   if (UNLIKELY(component_count < 0)) {
-    self->ThrowNewExceptionF("Ljava/lang/NegativeArraySizeException;", "%d", component_count);
+    ThrowNegativeArraySizeException(component_count);
     return NULL;  // Failure
   }
   mirror::Class* klass = method->GetDexCacheResolvedTypes()->Get(type_idx);
@@ -257,8 +258,9 @@
     UNLOCK_FUNCTION(monitor_lock_) {
   // Save any pending exception over monitor exit call.
   mirror::Throwable* saved_exception = NULL;
+  ThrowLocation saved_throw_location;
   if (UNLIKELY(self->IsExceptionPending())) {
-    saved_exception = self->GetException();
+    saved_exception = self->GetException(&saved_throw_location);
     self->ClearException();
   }
   // Decode locked object and unlock, before popping local references.
@@ -267,11 +269,11 @@
     LOG(FATAL) << "Synchronized JNI code returning with an exception:\n"
         << saved_exception->Dump()
         << "\nEncountered second exception during implicit MonitorExit:\n"
-        << self->GetException()->Dump();
+        << self->GetException(NULL)->Dump();
   }
   // Restore pending exception.
   if (saved_exception != NULL) {
-    self->SetException(saved_exception);
+    self->SetException(saved_throw_location, saved_exception);
   }
 }
 
@@ -280,14 +282,12 @@
   if (o == NULL) {
     return;
   }
+  mirror::AbstractMethod* m = self->GetCurrentMethod(NULL);
   if (o == kInvalidIndirectRefObject) {
-    JniAbortF(NULL, "invalid reference returned from %s",
-              PrettyMethod(self->GetCurrentMethod()).c_str());
+    JniAbortF(NULL, "invalid reference returned from %s", PrettyMethod(m).c_str());
   }
   // Make sure that the result is an instance of the type this method was expected to return.
-  mirror::AbstractMethod* m = self->GetCurrentMethod();
-  MethodHelper mh(m);
-  mirror::Class* return_type = mh.GetReturnType();
+  mirror::Class* return_type = MethodHelper(m).GetReturnType();
 
   if (!o->InstanceOf(return_type)) {
     JniAbortF(NULL, "attempt to return an instance of %s from %s",
diff --git a/src/stack.cc b/src/stack.cc
index 66051f2..8690a36 100644
--- a/src/stack.cc
+++ b/src/stack.cc
@@ -24,9 +24,28 @@
 #include "mirror/object_array-inl.h"
 #include "object_utils.h"
 #include "thread_list.h"
+#include "throw_location.h"
 
 namespace art {
 
+mirror::Object* ShadowFrame::GetThisObject() const {
+  mirror::AbstractMethod* m = GetMethod();
+  if (m->IsStatic()) {
+    return NULL;
+  } else if (m->IsNative()) {
+    return GetVRegReference(0);
+  } else {
+    const DexFile::CodeItem* code_item = MethodHelper(m).GetCodeItem();
+    CHECK(code_item != NULL) << PrettyMethod(m);
+    uint16_t reg = code_item->registers_size_ - code_item->ins_size_;
+    return GetVRegReference(reg);
+  }
+}
+
+ThrowLocation ShadowFrame::GetCurrentLocationForThrow() const {
+  return ThrowLocation(GetThisObject(), GetMethod(), GetDexPC());
+}
+
 size_t ManagedStack::NumJniShadowFrameReferences() const {
   size_t count = 0;
   for (const ManagedStack* current_fragment = this; current_fragment != NULL;
@@ -59,7 +78,7 @@
     : thread_(thread), cur_shadow_frame_(NULL),
       cur_quick_frame_(NULL), cur_quick_frame_pc_(0), num_frames_(0), cur_depth_(0),
       context_(context) {
-  DCHECK(thread == Thread::Current() || thread->IsSuspended());
+  DCHECK(thread == Thread::Current() || thread->IsSuspended()) << *thread;
 }
 
 uint32_t StackVisitor::GetDexPc() const {
@@ -72,6 +91,33 @@
   }
 }
 
+mirror::Object* StackVisitor::GetThisObject() const {
+  mirror::AbstractMethod* m = GetMethod();
+  if (m->IsStatic()) {
+    return NULL;
+  } else if (m->IsNative()) {
+    if (cur_quick_frame_ != NULL) {
+      StackIndirectReferenceTable* sirt =
+          reinterpret_cast<StackIndirectReferenceTable*>(
+              reinterpret_cast<char*>(cur_quick_frame_) +
+              m->GetSirtOffsetInBytes());
+      return sirt->GetReference(0);
+    } else {
+      return cur_shadow_frame_->GetVRegReference(0);
+    }
+  } else {
+    const DexFile::CodeItem* code_item = MethodHelper(m).GetCodeItem();
+    if (code_item == NULL) {
+      UNIMPLEMENTED(ERROR) << "Failed to determine this object of abstract or proxy method"
+          << PrettyMethod(m);
+      return NULL;
+    } else {
+      uint16_t reg = code_item->registers_size_ - code_item->ins_size_;
+      return reinterpret_cast<mirror::Object*>(GetVReg(m, reg, kReferenceVReg));
+    }
+  }
+}
+
 size_t StackVisitor::GetNativePcOffset() const {
   DCHECK(!IsShadowFrame());
   return GetMethod()->NativePcOffset(cur_quick_frame_pc_);
@@ -198,7 +244,7 @@
   return result;
 }
 
-InstrumentationStackFrame StackVisitor::GetInstrumentationStackFrame(uint32_t depth) const {
+instrumentation::InstrumentationStackFrame StackVisitor::GetInstrumentationStackFrame(uint32_t depth) const {
   return thread_->GetInstrumentationStack()->at(depth);
 }
 
@@ -221,9 +267,8 @@
 
 void StackVisitor::WalkStack(bool include_transitions) {
   DCHECK(thread_ == Thread::Current() || thread_->IsSuspended());
-  const std::deque<InstrumentationStackFrame>* instrumentation_stack =
-      thread_->GetInstrumentationStack();
-  bool method_tracing_active = instrumentation_stack != NULL;
+  CHECK_EQ(cur_depth_, 0U);
+  bool exit_stubs_installed = Runtime::Current()->GetInstrumentation()->AreExitStubsInstalled();
   uint32_t instrumentation_stack_depth = 0;
   for (const ManagedStack* current_fragment = thread_->GetManagedStack(); current_fragment != NULL;
        current_fragment = current_fragment->GetLink()) {
@@ -235,6 +280,7 @@
       DCHECK(current_fragment->GetTopShadowFrame() == NULL);
       mirror::AbstractMethod* method = *cur_quick_frame_;
       while (method != NULL) {
+        DCHECK(cur_quick_frame_pc_ != GetInstrumentationExitPc());
         SanityCheckFrame();
         bool should_continue = VisitFrame();
         if (UNLIKELY(!should_continue)) {
@@ -248,16 +294,24 @@
         size_t return_pc_offset = method->GetReturnPcOffsetInBytes();
         byte* return_pc_addr = reinterpret_cast<byte*>(cur_quick_frame_) + return_pc_offset;
         uintptr_t return_pc = *reinterpret_cast<uintptr_t*>(return_pc_addr);
-        if (UNLIKELY(method_tracing_active)) {
+        if (UNLIKELY(exit_stubs_installed)) {
           // While profiling, the return pc is restored from the side stack, except when walking
           // the stack for an exception where the side stack will be unwound in VisitFrame.
-          // TODO: stop using include_transitions as a proxy for is this the catch block visitor.
-          if (GetInstrumentationExitPc() == return_pc && !include_transitions) {
-            // TODO: unify trace and managed stack.
-            InstrumentationStackFrame instrumentation_frame = GetInstrumentationStackFrame(instrumentation_stack_depth);
+          if (GetInstrumentationExitPc() == return_pc) {
+            instrumentation::InstrumentationStackFrame instrumentation_frame =
+                GetInstrumentationStackFrame(instrumentation_stack_depth);
             instrumentation_stack_depth++;
-            CHECK(instrumentation_frame.method_ == GetMethod()) << "Excepted: " << PrettyMethod(method)
+            if (instrumentation_frame.method_ != GetMethod()) {
+              LOG(FATAL)  << "Expected: " << PrettyMethod(instrumentation_frame.method_)
                 << " Found: " << PrettyMethod(GetMethod());
+            }
+            if (num_frames_ != 0) {
+              // Check agreement of frame Ids only if num_frames_ is computed to avoid infinite
+              // recursion.
+              CHECK(instrumentation_frame.frame_id_ == GetFrameId())
+                    << "Expected: " << instrumentation_frame.frame_id_
+                    << " Found: " << GetFrameId();
+            }
             return_pc = instrumentation_frame.return_pc_;
           }
         }
@@ -278,13 +332,16 @@
         cur_shadow_frame_ = cur_shadow_frame_->GetLink();
       } while(cur_shadow_frame_ != NULL);
     }
-    cur_depth_++;
     if (include_transitions) {
       bool should_continue = VisitFrame();
       if (!should_continue) {
         return;
       }
     }
+    cur_depth_++;
+  }
+  if (num_frames_ != 0) {
+    CHECK_EQ(cur_depth_, num_frames_);
   }
 }
 
diff --git a/src/stack.h b/src/stack.h
index e0cb28e..eb187b2 100644
--- a/src/stack.h
+++ b/src/stack.h
@@ -168,6 +168,10 @@
     return method_;
   }
 
+  mirror::Object* GetThisObject() const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+  ThrowLocation GetCurrentLocationForThrow() const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
   void SetMethod(mirror::AbstractMethod* method) {
     DCHECK_NE(method, static_cast<void*>(NULL));
     method_ = method;
@@ -368,6 +372,8 @@
 
   uint32_t GetDexPc() const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
+  mirror::Object* GetThisObject() const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
   size_t GetNativePcOffset() const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
   uintptr_t* CalleeSaveAddress(int num, size_t frame_size) const {
@@ -383,7 +389,7 @@
 
   // Returns the height of the stack in the managed stack frames, including transitions.
   size_t GetFrameHeight() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
-    return GetNumFrames() - cur_depth_;
+    return GetNumFrames() - cur_depth_ - 1;
   }
 
   // Returns a frame ID for JDWP use, starting from 1.
@@ -503,7 +509,7 @@
 
  private:
 
-  InstrumentationStackFrame GetInstrumentationStackFrame(uint32_t depth) const;
+  instrumentation::InstrumentationStackFrame GetInstrumentationStackFrame(uint32_t depth) const;
 
   void SanityCheckFrame() const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
diff --git a/src/thread.cc b/src/thread.cc
index 9c58b6d..2c955b1 100644
--- a/src/thread.cc
+++ b/src/thread.cc
@@ -61,6 +61,7 @@
 #include "thread_list.h"
 #include "utils.h"
 #include "verifier/dex_gc_map.h"
+#include "verifier/method_verifier.h"
 #include "well_known_classes.h"
 
 namespace art {
@@ -92,24 +93,16 @@
   InitEntryPoints(&entrypoints_);
 }
 
-void Thread::SetDebuggerUpdatesEnabled(bool enabled) {
-#if !defined(ART_USE_PORTABLE_COMPILER)
-  ChangeDebuggerEntryPoint(&entrypoints_, enabled);
-#else
-  UNIMPLEMENTED(FATAL);
-#endif
+void Thread::SetDeoptimizationShadowFrame(ShadowFrame* sf) {
+  deoptimization_shadow_frame_ = sf;
 }
 
-
-void Thread::SetDeoptimizationShadowFrame(ShadowFrame* sf, const JValue& ret_val) {
-  CHECK(sf != NULL);
-  deoptimization_shadow_frame_ = sf;
+void Thread::SetDeoptimizationReturnValue(const JValue& ret_val) {
   deoptimization_return_value_.SetJ(ret_val.GetJ());
 }
 
 ShadowFrame* Thread::GetAndClearDeoptimizationShadowFrame(JValue* ret_val) {
   ShadowFrame* sf = deoptimization_shadow_frame_;
-  DCHECK(sf != NULL);
   deoptimization_shadow_frame_ = NULL;
   ret_val->SetJ(deoptimization_return_value_.GetJ());
   return sf;
@@ -327,9 +320,6 @@
   InitFunctionPointers();
   InitCardTable();
   InitTid();
-  if (Runtime::Current()->InterpreterOnly()) {
-    AtomicSetFlag(kEnterInterpreter);
-  }
   // Set pthread_self_ ahead of pthread_setspecific, that makes Thread::Current function, this
   // avoids pthread_self_ ever being invalid when discovered from Thread::Current().
   pthread_self_ = pthread_self();
@@ -864,7 +854,7 @@
   // We don't just check kNative because native methods will be in state kSuspended if they're
   // calling back into the VM, or kBlocked if they're blocked on a monitor, or one of the
   // thread-startup states if it's early enough in their life cycle (http://b/7432159).
-  mirror::AbstractMethod* current_method = thread->GetCurrentMethod();
+  mirror::AbstractMethod* current_method = thread->GetCurrentMethod(NULL);
   return current_method != NULL && current_method->IsNative();
 }
 
@@ -948,7 +938,8 @@
       throwing_OutOfMemoryError_(false),
       debug_suspend_count_(0),
       debug_invoke_req_(new DebugInvokeReq),
-      instrumentation_stack_(new std::deque<InstrumentationStackFrame>),
+      deoptimization_shadow_frame_(NULL),
+      instrumentation_stack_(new std::deque<instrumentation::InstrumentationStackFrame>),
       name_(new std::string(kThreadNameDuringStartup)),
       daemon_(daemon),
       pthread_self_(0),
@@ -975,7 +966,7 @@
 void Thread::AssertNoPendingException() const {
   if (UNLIKELY(IsExceptionPending())) {
     ScopedObjectAccess soa(Thread::Current());
-    mirror::Throwable* exception = GetException();
+    mirror::Throwable* exception = GetException(NULL);
     LOG(FATAL) << "No pending exception expected: " << exception->Dump();
   }
 }
@@ -1427,82 +1418,131 @@
   return result;
 }
 
-void Thread::ThrowNewExceptionF(const char* exception_class_descriptor, const char* fmt, ...) {
+void Thread::ThrowNewExceptionF(const ThrowLocation& throw_location,
+                                const char* exception_class_descriptor, const char* fmt, ...) {
   va_list args;
   va_start(args, fmt);
-  ThrowNewExceptionV(exception_class_descriptor, fmt, args);
+  ThrowNewExceptionV(throw_location, exception_class_descriptor,
+                     fmt, args);
   va_end(args);
 }
 
-void Thread::ThrowNewExceptionV(const char* exception_class_descriptor, const char* fmt, va_list ap) {
+void Thread::ThrowNewExceptionV(const ThrowLocation& throw_location,
+                                const char* exception_class_descriptor,
+                                const char* fmt, va_list ap) {
   std::string msg;
   StringAppendV(&msg, fmt, ap);
-  ThrowNewException(exception_class_descriptor, msg.c_str());
+  ThrowNewException(throw_location, exception_class_descriptor, msg.c_str());
 }
 
-void Thread::ThrowNewException(const char* exception_class_descriptor, const char* msg) {
+void Thread::ThrowNewException(const ThrowLocation& throw_location, const char* exception_class_descriptor,
+                               const char* msg) {
   AssertNoPendingException(); // Callers should either clear or call ThrowNewWrappedException.
-  ThrowNewWrappedException(exception_class_descriptor, msg);
+  ThrowNewWrappedException(throw_location, exception_class_descriptor, msg);
 }
 
-void Thread::ThrowNewWrappedException(const char* exception_class_descriptor, const char* msg) {
-  // Convert "Ljava/lang/Exception;" into JNI-style "java/lang/Exception".
-  CHECK_EQ('L', exception_class_descriptor[0]);
-  std::string descriptor(exception_class_descriptor + 1);
-  CHECK_EQ(';', descriptor[descriptor.length() - 1]);
-  descriptor.erase(descriptor.length() - 1);
+void Thread::ThrowNewWrappedException(const ThrowLocation& throw_location,
+                                      const char* exception_class_descriptor,
+                                      const char* msg) {
+  DCHECK_EQ(this, Thread::Current());
+  // Ensure we don't forget arguments over object allocation.
+  SirtRef<mirror::Object> saved_throw_this(this, throw_location.GetThis());
+  SirtRef<mirror::AbstractMethod> saved_throw_method(this, throw_location.GetMethod());
+  // Ignore the cause throw location. TODO: should we report this as a re-throw?
+  SirtRef<mirror::Throwable> cause(this, GetException(NULL));
+  ClearException();
+  Runtime* runtime = Runtime::Current();
 
-  JNIEnv* env = GetJniEnv();
-  jobject cause = env->ExceptionOccurred();
-  env->ExceptionClear();
-
-  ScopedLocalRef<jclass> exception_class(env, env->FindClass(descriptor.c_str()));
-  if (exception_class.get() == NULL) {
-    LOG(ERROR) << "Couldn't throw new " << descriptor << " because JNI FindClass failed: "
-               << PrettyTypeOf(GetException());
+  mirror::ClassLoader* cl = NULL;
+  if (throw_location.GetMethod() != NULL) {
+    cl = throw_location.GetMethod()->GetDeclaringClass()->GetClassLoader();
+  }
+  SirtRef<mirror::Class>
+      exception_class(this, runtime->GetClassLinker()->FindClass(exception_class_descriptor, cl));
+  if (UNLIKELY(exception_class.get() == NULL)) {
     CHECK(IsExceptionPending());
+    LOG(ERROR) << "No exception class " << PrettyDescriptor(exception_class_descriptor);
     return;
   }
-  if (!Runtime::Current()->IsStarted()) {
-    // Something is trying to throw an exception without a started
-    // runtime, which is the common case in the compiler. We won't be
-    // able to invoke the constructor of the exception, so use
-    // AllocObject which will not invoke a constructor.
-    ScopedLocalRef<jthrowable> exception(
-        env, reinterpret_cast<jthrowable>(env->AllocObject(exception_class.get())));
-    if (exception.get() != NULL) {
-      ScopedObjectAccessUnchecked soa(env);
-      mirror::Throwable* t =
-          reinterpret_cast<mirror::Throwable*>(soa.Self()->DecodeJObject(exception.get()));
-      t->SetDetailMessage(mirror::String::AllocFromModifiedUtf8(soa.Self(), msg));
-      if (cause != NULL) {
-        t->SetCause(soa.Decode<mirror::Throwable*>(cause));
-      }
-      soa.Self()->SetException(t);
-    } else {
-      LOG(ERROR) << "Couldn't throw new " << descriptor << " because JNI AllocObject failed: "
-                 << PrettyTypeOf(GetException());
-      CHECK(IsExceptionPending());
+
+  if (UNLIKELY(!runtime->GetClassLinker()->EnsureInitialized(exception_class.get(), true, true))) {
+    DCHECK(IsExceptionPending());
+    return;
+  }
+  DCHECK(!runtime->IsStarted() || exception_class->IsThrowableClass());
+  SirtRef<mirror::Throwable> exception(this,
+                                down_cast<mirror::Throwable*>(exception_class->AllocObject(this)));
+
+  // Choose an appropriate constructor and set up the arguments.
+  const char* signature;
+  SirtRef<mirror::String> msg_string(this, NULL);
+  if (msg != NULL) {
+    // Ensure we remember this and the method over the String allocation.
+    msg_string.reset(mirror::String::AllocFromModifiedUtf8(this, msg));
+    if (UNLIKELY(msg_string.get() == NULL)) {
+      CHECK(IsExceptionPending());  // OOME.
+      return;
     }
-    return;
+    if (cause.get() == NULL) {
+      signature = "(Ljava/lang/String;)V";
+    } else {
+      signature = "(Ljava/lang/String;Ljava/lang/Throwable;)V";
+    }
+  } else {
+    if (cause.get() == NULL) {
+      signature = "()V";
+    } else {
+      signature = "(Ljava/lang/Throwable;)V";
+    }
   }
-  int rc = ::art::ThrowNewException(env, exception_class.get(), msg, cause);
-  if (rc != JNI_OK) {
-    LOG(ERROR) << "Couldn't throw new " << descriptor << " because JNI ThrowNew failed: "
-               << PrettyTypeOf(GetException());
-    CHECK(IsExceptionPending());
+  mirror::AbstractMethod* exception_init_method =
+      exception_class->FindDeclaredDirectMethod("<init>", signature);
+
+  CHECK(exception_init_method != NULL) << "No <init>" << signature << " in "
+      << PrettyDescriptor(exception_class_descriptor);
+
+  if (UNLIKELY(!runtime->IsStarted())) {
+    // Something is trying to throw an exception without a started runtime, which is the common
+    // case in the compiler. We won't be able to invoke the constructor of the exception, so set
+    // the exception fields directly.
+    if (msg != NULL) {
+      exception->SetDetailMessage(msg_string.get());
+    }
+    if (cause.get() != NULL) {
+      exception->SetCause(cause.get());
+    }
+    ThrowLocation gc_safe_throw_location(saved_throw_this.get(), saved_throw_method.get(),
+                                         throw_location.GetDexPc());
+    SetException(gc_safe_throw_location, exception.get());
+  } else {
+    ArgArray args("VLL", 3);
+    args.Append(reinterpret_cast<uint32_t>(exception.get()));
+    if (msg != NULL) {
+      args.Append(reinterpret_cast<uint32_t>(msg_string.get()));
+    }
+    if (cause.get() != NULL) {
+      args.Append(reinterpret_cast<uint32_t>(cause.get()));
+    }
+    JValue result;
+    exception_init_method->Invoke(this, args.GetArray(), args.GetNumBytes(), &result, 'V');
+    if (LIKELY(!IsExceptionPending())) {
+      ThrowLocation gc_safe_throw_location(saved_throw_this.get(), saved_throw_method.get(),
+                                           throw_location.GetDexPc());
+      SetException(gc_safe_throw_location, exception.get());
+    }
   }
 }
 
 void Thread::ThrowOutOfMemoryError(const char* msg) {
   LOG(ERROR) << StringPrintf("Throwing OutOfMemoryError \"%s\"%s",
       msg, (throwing_OutOfMemoryError_ ? " (recursive case)" : ""));
+  ThrowLocation throw_location = GetCurrentLocationForThrow();
   if (!throwing_OutOfMemoryError_) {
     throwing_OutOfMemoryError_ = true;
-    ThrowNewException("Ljava/lang/OutOfMemoryError;", msg);
+    ThrowNewException(throw_location, "Ljava/lang/OutOfMemoryError;", msg);
   } else {
     Dump(LOG(ERROR)); // The pre-allocated OOME has no stack, so help out and log one.
-    SetException(Runtime::Current()->GetPreAllocatedOutOfMemoryError());
+    SetException(throw_location, Runtime::Current()->GetPreAllocatedOutOfMemoryError());
   }
   throwing_OutOfMemoryError_ = false;
 }
@@ -1538,8 +1578,6 @@
   ENTRY_POINT_INFO(pInstanceofNonTrivialFromCode),
   ENTRY_POINT_INFO(pCanPutArrayElementFromCode),
   ENTRY_POINT_INFO(pCheckCastFromCode),
-  ENTRY_POINT_INFO(pDebugMe),
-  ENTRY_POINT_INFO(pUpdateDebuggerFromCode),
   ENTRY_POINT_INFO(pInitializeStaticStorage),
   ENTRY_POINT_INFO(pInitializeTypeAndVerifyAccessFromCode),
   ENTRY_POINT_INFO(pInitializeTypeFromCode),
@@ -1644,13 +1682,17 @@
 static const bool kDebugExceptionDelivery = false;
 class CatchBlockStackVisitor : public StackVisitor {
  public:
-  CatchBlockStackVisitor(Thread* self, mirror::Throwable* exception)
+  CatchBlockStackVisitor(Thread* self, const ThrowLocation& throw_location,
+                         mirror::Throwable* exception, bool is_deoptimization)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_)
       : StackVisitor(self, self->GetLongJumpContext()),
-        self_(self), exception_(exception), to_find_(exception->GetClass()), throw_method_(NULL),
-        throw_frame_id_(0), throw_dex_pc_(0), handler_quick_frame_(NULL),
-        handler_quick_frame_pc_(0), handler_dex_pc_(0), native_method_count_(0),
-        method_tracing_active_(Runtime::Current()->IsMethodTracingActive()) {
+        self_(self), exception_(exception), is_deoptimization_(is_deoptimization),
+        to_find_(is_deoptimization ? NULL : exception->GetClass()), throw_location_(throw_location),
+        handler_quick_frame_(NULL), handler_quick_frame_pc_(0), handler_dex_pc_(0),
+        native_method_count_(0),
+        method_tracing_active_(is_deoptimization ||
+                               Runtime::Current()->GetInstrumentation()->AreExitStubsInstalled()),
+        instrumentation_frames_to_pop_(0), top_shadow_frame_(NULL), prev_shadow_frame_(NULL) {
     // Exception not in root sets, can't allow GC.
     last_no_assert_suspension_cause_ = self->StartAssertNoThreadSuspension("Finding catch block");
   }
@@ -1659,38 +1701,38 @@
     LOG(FATAL) << "UNREACHABLE";  // Expected to take long jump.
   }
 
-  bool VisitFrame() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_)
-      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+  bool VisitFrame() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
     mirror::AbstractMethod* method = GetMethod();
     if (method == NULL) {
       // This is the upcall, we remember the frame and last pc so that we may long jump to them.
       handler_quick_frame_pc_ = GetCurrentQuickFramePc();
       handler_quick_frame_ = GetCurrentQuickFrame();
       return false;  // End stack walk.
-    }
-    uint32_t dex_pc = DexFile::kDexNoIndex;
-    if (method->IsRuntimeMethod()) {
-      // ignore callee save method
-      DCHECK(method->IsCalleeSaveMethod());
     } else {
-      if (throw_method_ == NULL) {
-        throw_method_ = method;
-        throw_frame_id_ = GetFrameId();
-        throw_dex_pc_ = GetDexPc();
+      if (UNLIKELY(method_tracing_active_ &&
+                   GetInstrumentationExitPc() == GetReturnPc())) {
+        // Keep count of the number of unwinds during instrumentation.
+        instrumentation_frames_to_pop_++;
       }
-      if (method->IsNative()) {
-        native_method_count_++;
+      if (method->IsRuntimeMethod()) {
+        // Ignore callee save method.
+        DCHECK(method->IsCalleeSaveMethod());
+        return true;
+      } else if (is_deoptimization_) {
+        return HandleDeoptimization(method);
       } else {
-        // Unwind stack when an exception occurs during instrumentation
-        if (UNLIKELY(method_tracing_active_ &&
-                     GetInstrumentationExitPc() == GetCurrentQuickFramePc())) {
-          uintptr_t pc = InstrumentationMethodUnwindFromCode(Thread::Current());
-          dex_pc = method->ToDexPc(pc);
-        } else {
-          dex_pc = GetDexPc();
-        }
+        return HandleTryItems(method);
       }
     }
+  }
+
+  bool HandleTryItems(mirror::AbstractMethod* method) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+    uint32_t dex_pc = DexFile::kDexNoIndex;
+    if (method->IsNative()) {
+      native_method_count_++;
+    } else {
+      dex_pc = GetDexPc();
+    }
     if (dex_pc != DexFile::kDexNoIndex) {
       uint32_t found_dex_pc = method->FindCatchBlock(to_find_, dex_pc);
       if (found_dex_pc != DexFile::kDexNoIndex) {
@@ -1703,22 +1745,81 @@
     return true;  // Continue stack walk.
   }
 
+  bool HandleDeoptimization(mirror::AbstractMethod* m) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+    MethodHelper mh(m);
+    const DexFile::CodeItem* code_item = mh.GetCodeItem();
+    CHECK(code_item != NULL);
+    uint16_t num_regs =  code_item->registers_size_;
+    uint32_t dex_pc = GetDexPc();
+    const Instruction* inst = Instruction::At(code_item->insns_ + dex_pc);
+    uint32_t new_dex_pc = dex_pc + inst->SizeInCodeUnits();
+    ShadowFrame* new_frame = ShadowFrame::Create(num_regs, NULL, m, new_dex_pc);
+    verifier::MethodVerifier verifier(&mh.GetDexFile(), mh.GetDexCache(), mh.GetClassLoader(),
+                                      mh.GetClassDefIndex(), code_item,
+                                      m->GetDexMethodIndex(), m, m->GetAccessFlags(), false);
+    verifier.Verify();
+    std::vector<int32_t> kinds = verifier.DescribeVRegs(dex_pc);
+    for(uint16_t reg = 0; reg < num_regs; reg++) {
+      VRegKind kind = static_cast<VRegKind>(kinds.at(reg * 2));
+      switch (kind) {
+        case kUndefined:
+          new_frame->SetVReg(reg, 0xEBADDE09);
+          break;
+        case kConstant:
+          new_frame->SetVReg(reg, kinds.at((reg * 2) + 1));
+          break;
+        case kReferenceVReg:
+          new_frame->SetVRegReference(reg,
+                                      reinterpret_cast<mirror::Object*>(GetVReg(m, reg, kind)));
+          break;
+        default:
+          new_frame->SetVReg(reg, GetVReg(m, reg, kind));
+          break;
+      }
+    }
+    if (prev_shadow_frame_ != NULL) {
+      prev_shadow_frame_->SetLink(new_frame);
+    } else {
+      top_shadow_frame_ = new_frame;
+    }
+    prev_shadow_frame_ = new_frame;
+    return true;
+  }
+
   void DoLongJump() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
     mirror::AbstractMethod* catch_method = *handler_quick_frame_;
-    if (kDebugExceptionDelivery) {
-      if (catch_method == NULL) {
+    if (catch_method == NULL) {
+      if (kDebugExceptionDelivery) {
         LOG(INFO) << "Handler is upcall";
-      } else {
+      }
+    } else {
+      CHECK(!is_deoptimization_);
+      if (instrumentation_frames_to_pop_ > 0) {
+        // Don't pop the instrumentation frame of the catch handler.
+        instrumentation_frames_to_pop_--;
+      }
+      if (kDebugExceptionDelivery) {
         const DexFile& dex_file = *catch_method->GetDeclaringClass()->GetDexCache()->GetDexFile();
         int line_number = dex_file.GetLineNumFromPC(catch_method, handler_dex_pc_);
         LOG(INFO) << "Handler: " << PrettyMethod(catch_method) << " (line: " << line_number << ")";
       }
     }
-    self_->SetException(exception_);  // Exception back in root set.
+    // Put exception back in root set and clear throw location.
+    self_->SetException(ThrowLocation(), exception_);
     self_->EndAssertNoThreadSuspension(last_no_assert_suspension_cause_);
-    // Do debugger PostException after allowing thread suspension again.
-    Dbg::PostException(self_, throw_frame_id_, throw_method_, throw_dex_pc_,
-                       catch_method, handler_dex_pc_, exception_);
+    // Do instrumentation events after allowing thread suspension again.
+    instrumentation::Instrumentation* instrumentation = Runtime::Current()->GetInstrumentation();
+    for (size_t i = 0; i < instrumentation_frames_to_pop_; ++i) {
+      // We pop the instrumentation stack here so as not to corrupt it during the stack walk.
+      instrumentation->PopMethodForUnwind(self_, is_deoptimization_);
+    }
+    if (!is_deoptimization_) {
+      instrumentation->ExceptionCaughtEvent(self_, throw_location_, catch_method, handler_dex_pc_,
+                                            exception_);
+    } else {
+      // TODO: proper return value.
+      self_->SetDeoptimizationShadowFrame(top_shadow_frame_);
+    }
     // Place context back on thread so it will be available when we continue.
     self_->ReleaseLongJumpContext(context_);
     context_->SetSP(reinterpret_cast<uintptr_t>(handler_quick_frame_));
@@ -1729,13 +1830,13 @@
   }
 
  private:
-  Thread* self_;
-  mirror::Throwable* exception_;
+  Thread* const self_;
+  mirror::Throwable* const exception_;
+  const bool is_deoptimization_;
   // The type of the exception catch block to find.
-  mirror::Class* to_find_;
-  mirror::AbstractMethod* throw_method_;
-  JDWP::FrameId throw_frame_id_;
-  uint32_t throw_dex_pc_;
+  mirror::Class* const to_find_;
+  // Location of the throw.
+  const ThrowLocation& throw_location_;
   // Quick frame with found handler or last frame if no handler found.
   mirror::AbstractMethod** handler_quick_frame_;
   // PC to branch to for the handler.
@@ -1748,21 +1849,32 @@
   const bool method_tracing_active_;
   // Support for nesting no thread suspension checks.
   const char* last_no_assert_suspension_cause_;
+  // Number of frames to pop in long jump.
+  size_t instrumentation_frames_to_pop_;
+  ShadowFrame* top_shadow_frame_;
+  ShadowFrame* prev_shadow_frame_;
 };
 
 void Thread::QuickDeliverException() {
-  mirror::Throwable* exception = GetException();  // Get exception from thread
+  // Get exception from thread.
+  ThrowLocation throw_location;
+  mirror::Throwable* exception = GetException(&throw_location);
   CHECK(exception != NULL);
   // Don't leave exception visible while we try to find the handler, which may cause class
   // resolution.
   ClearException();
+  bool is_deoptimization = (exception == reinterpret_cast<mirror::Throwable*>(-1));
   if (kDebugExceptionDelivery) {
-    mirror::String* msg = exception->GetDetailMessage();
-    std::string str_msg(msg != NULL ? msg->ToModifiedUtf8() : "");
-    DumpStack(LOG(INFO) << "Delivering exception: " << PrettyTypeOf(exception)
-                        << ": " << str_msg << "\n");
+    if (!is_deoptimization) {
+      mirror::String* msg = exception->GetDetailMessage();
+      std::string str_msg(msg != NULL ? msg->ToModifiedUtf8() : "");
+      DumpStack(LOG(INFO) << "Delivering exception: " << PrettyTypeOf(exception)
+                << ": " << str_msg << "\n");
+    } else {
+      DumpStack(LOG(INFO) << "Deoptimizing: ");
+    }
   }
-  CatchBlockStackVisitor catch_finder(this, exception);
+  CatchBlockStackVisitor catch_finder(this, throw_location, exception, is_deoptimization);
   catch_finder.WalkStack(true);
   catch_finder.DoLongJump();
   LOG(FATAL) << "UNREACHABLE";
@@ -1779,39 +1891,45 @@
   return result;
 }
 
-mirror::AbstractMethod* Thread::GetCurrentMethod(uint32_t* dex_pc, size_t* frame_id) const {
-  struct CurrentMethodVisitor : public StackVisitor {
-    CurrentMethodVisitor(Thread* thread)
-        SHARED_LOCKS_REQUIRED(Locks::mutator_lock_)
-        : StackVisitor(thread, NULL), method_(NULL), dex_pc_(0), frame_id_(0) {}
-
-    virtual bool VisitFrame() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
-      mirror::AbstractMethod* m = GetMethod();
-      if (m->IsRuntimeMethod()) {
-        // Continue if this is a runtime method.
-        return true;
-      }
-      method_ = m;
-      dex_pc_ = GetDexPc();
-      frame_id_ = GetFrameId();
-      return false;
+struct CurrentMethodVisitor : public StackVisitor {
+  CurrentMethodVisitor(Thread* thread, Context* context)
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_)
+      : StackVisitor(thread, context), this_object_(NULL), method_(NULL), dex_pc_(0) {}
+  virtual bool VisitFrame() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+    mirror::AbstractMethod* m = GetMethod();
+    if (m->IsRuntimeMethod()) {
+      // Continue if this is a runtime method.
+      return true;
     }
-    mirror::AbstractMethod* method_;
-    uint32_t dex_pc_;
-    size_t frame_id_;
-  };
+    if (context_ != NULL) {
+      this_object_ = GetThisObject();
+    }
+    method_ = m;
+    dex_pc_ = GetDexPc();
+    return false;
+  }
+  mirror::Object* this_object_;
+  mirror::AbstractMethod* method_;
+  uint32_t dex_pc_;
+};
 
-  CurrentMethodVisitor visitor(const_cast<Thread*>(this));
+mirror::AbstractMethod* Thread::GetCurrentMethod(uint32_t* dex_pc) const {
+  CurrentMethodVisitor visitor(const_cast<Thread*>(this), NULL);
   visitor.WalkStack(false);
   if (dex_pc != NULL) {
     *dex_pc = visitor.dex_pc_;
   }
-  if (frame_id != NULL) {
-    *frame_id = visitor.frame_id_;
-  }
   return visitor.method_;
 }
 
+ThrowLocation Thread::GetCurrentLocationForThrow() {
+  Context* context = GetLongJumpContext();
+  CurrentMethodVisitor visitor(this, context);
+  visitor.WalkStack(false);
+  ReleaseLongJumpContext(context);
+  return ThrowLocation(visitor.this_object_, visitor.method_, visitor.dex_pc_);
+}
+
 bool Thread::HoldsLock(mirror::Object* object) {
   if (object == NULL) {
     return false;
@@ -1981,6 +2099,7 @@
   if (exception_ != NULL) {
     VerifyRootWrapperCallback(exception_, &wrapperArg);
   }
+  throw_location_.VisitRoots(VerifyRootWrapperCallback, &wrapperArg);
   if (class_loader_override_ != NULL) {
     VerifyRootWrapperCallback(class_loader_override_, &wrapperArg);
   }
@@ -1995,6 +2114,17 @@
   ReferenceMapVisitor<VerifyCallbackVisitor> mapper(this, context, visitorToCallback);
   mapper.WalkStack();
   ReleaseLongJumpContext(context);
+
+  std::deque<instrumentation::InstrumentationStackFrame>* instrumentation_stack = GetInstrumentationStack();
+  typedef std::deque<instrumentation::InstrumentationStackFrame>::const_iterator It;
+  for (It it = instrumentation_stack->begin(), end = instrumentation_stack->end(); it != end; ++it) {
+    mirror::Object* this_object = (*it).this_object_;
+    if (this_object != NULL) {
+      VerifyRootWrapperCallback(this_object, &wrapperArg);
+    }
+    mirror::AbstractMethod* method = (*it).method_;
+    VerifyRootWrapperCallback(method, &wrapperArg);
+  }
 }
 
 void Thread::VisitRoots(RootVisitor* visitor, void* arg) {
@@ -2004,6 +2134,7 @@
   if (exception_ != NULL) {
     visitor(exception_, arg);
   }
+  throw_location_.VisitRoots(visitor, arg);
   if (class_loader_override_ != NULL) {
     visitor(class_loader_override_, arg);
   }
@@ -2018,6 +2149,17 @@
   ReferenceMapVisitor<RootCallbackVisitor> mapper(this, context, visitorToCallback);
   mapper.WalkStack();
   ReleaseLongJumpContext(context);
+
+  std::deque<instrumentation::InstrumentationStackFrame>* instrumentation_stack = GetInstrumentationStack();
+  typedef std::deque<instrumentation::InstrumentationStackFrame>::const_iterator It;
+  for (It it = instrumentation_stack->begin(), end = instrumentation_stack->end(); it != end; ++it) {
+    mirror::Object* this_object = (*it).this_object_;
+    if (this_object != NULL) {
+      visitor(this_object, arg);
+    }
+    mirror::AbstractMethod* method = (*it).method_;
+    visitor(method, arg);
+  }
 }
 
 static void VerifyObject(const mirror::Object* root, void* arg) {
diff --git a/src/thread.h b/src/thread.h
index dd67a21..37f2721 100644
--- a/src/thread.h
+++ b/src/thread.h
@@ -36,6 +36,7 @@
 #include "stack.h"
 #include "stack_indirect_reference_table.h"
 #include "thread_state.h"
+#include "throw_location.h"
 #include "UniquePtr.h"
 
 namespace art {
@@ -80,14 +81,13 @@
 enum ThreadFlag {
   kSuspendRequest   = 1,  // If set implies that suspend_count_ > 0 and the Thread should enter the
                           // safepoint handler.
-  kCheckpointRequest = 2, // Request that the thread do some checkpoint work and then continue.
-  kEnterInterpreter = 4,  // Instruct managed code it should enter the interpreter.
+  kCheckpointRequest = 2  // Request that the thread do some checkpoint work and then continue.
 };
 
 class PACKED(4) Thread {
  public:
   // Space to throw a StackOverflowError in.
-  static const size_t kStackOverflowReservedBytes = 10 * KB;
+  static const size_t kStackOverflowReservedBytes = 16 * KB;
 
   // Creates a new native thread corresponding to the given managed peer.
   // Used to implement Thread.start.
@@ -279,28 +279,27 @@
     return exception_ != NULL;
   }
 
-  mirror::Throwable* GetException() const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+  mirror::Throwable* GetException(ThrowLocation* throw_location) const
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+    if (throw_location != NULL) {
+      *throw_location = throw_location_;
+    }
     return exception_;
   }
 
   void AssertNoPendingException() const;
 
-  void SetException(mirror::Throwable* new_exception) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+  void SetException(const ThrowLocation& throw_location, mirror::Throwable* new_exception)
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
     CHECK(new_exception != NULL);
     // TODO: DCHECK(!IsExceptionPending());
     exception_ = new_exception;
+    throw_location_ = throw_location;
   }
 
   void ClearException() {
     exception_ = NULL;
-  }
-
-  void DeliverException(mirror::Throwable* exception) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
-    if (exception == NULL) {
-      ThrowNewException("Ljava/lang/NullPointerException;", "throw with null exception");
-    } else {
-      SetException(exception);
-    }
+    throw_location_.Clear();
   }
 
   // Find catch block and perform long jump to appropriate exception handle
@@ -312,9 +311,11 @@
     long_jump_context_ = context;
   }
 
-  mirror::AbstractMethod* GetCurrentMethod(uint32_t* dex_pc = NULL, size_t* frame_id = NULL) const
+  mirror::AbstractMethod* GetCurrentMethod(uint32_t* dex_pc) const
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
+  ThrowLocation GetCurrentLocationForThrow() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
   void SetTopOfStack(void* stack, uintptr_t pc) {
     mirror::AbstractMethod** top_method = reinterpret_cast<mirror::AbstractMethod**>(stack);
     managed_stack_.SetTopQuickFrame(top_method);
@@ -330,32 +331,30 @@
   }
 
   // If 'msg' is NULL, no detail message is set.
-  void ThrowNewException(const char* exception_class_descriptor, const char* msg)
+  void ThrowNewException(const ThrowLocation& throw_location,
+                         const char* exception_class_descriptor, const char* msg)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
   // If 'msg' is NULL, no detail message is set. An exception must be pending, and will be
   // used as the new exception's cause.
-  void ThrowNewWrappedException(const char* exception_class_descriptor, const char* msg)
+  void ThrowNewWrappedException(const ThrowLocation& throw_location,
+                                const char* exception_class_descriptor,
+                                const char* msg)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
-  void ThrowNewExceptionF(const char* exception_class_descriptor, const char* fmt, ...)
-      __attribute__((format(printf, 3, 4)))
+  void ThrowNewExceptionF(const ThrowLocation& throw_location,
+                          const char* exception_class_descriptor, const char* fmt, ...)
+      __attribute__((format(printf, 4, 5)))
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
-  void ThrowNewExceptionV(const char* exception_class_descriptor, const char* fmt, va_list ap)
+  void ThrowNewExceptionV(const ThrowLocation& throw_location,
+                          const char* exception_class_descriptor, const char* fmt, va_list ap)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
   // OutOfMemoryError is special, because we need to pre-allocate an instance.
   // Only the GC should call this.
   void ThrowOutOfMemoryError(const char* msg) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
-  //QuickFrameIterator FindExceptionHandler(void* throw_pc, void** handler_pc);
-
-  void* FindExceptionHandlerInMethod(const mirror::AbstractMethod* method,
-                                     void* throw_pc,
-                                     const DexFile& dex_file,
-                                     ClassLinker* class_linker);
-
   static void Startup();
   static void FinishStartup();
   static void Shutdown();
@@ -395,8 +394,7 @@
   static jobjectArray InternalStackTraceToStackTraceElementArray(JNIEnv* env, jobject internal,
       jobjectArray output_array = NULL, int* stack_depth = NULL);
 
-  void VisitRoots(RootVisitor* visitor, void* arg)
-      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+  void VisitRoots(RootVisitor* visitor, void* arg) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
   void VerifyRoots(VerifyRootVisitor* visitor, void* arg)
       SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
@@ -535,34 +533,15 @@
     return debug_invoke_req_;
   }
 
-  void SetDebuggerUpdatesEnabled(bool enabled);
-
-  void SetDeoptimizationShadowFrame(ShadowFrame* sf, const JValue& ret_val);
+  void SetDeoptimizationShadowFrame(ShadowFrame* sf);
+  void SetDeoptimizationReturnValue(const JValue& ret_val);
 
   ShadowFrame* GetAndClearDeoptimizationShadowFrame(JValue* ret_val);
 
-  const std::deque<InstrumentationStackFrame>* GetInstrumentationStack() const {
+  std::deque<instrumentation::InstrumentationStackFrame>* GetInstrumentationStack() {
     return instrumentation_stack_;
   }
 
-  bool IsInstrumentationStackEmpty() const {
-    return instrumentation_stack_->empty();
-  }
-
-  void PushInstrumentationStackFrame(const InstrumentationStackFrame& frame) {
-    instrumentation_stack_->push_front(frame);
-  }
-
-  void PushBackInstrumentationStackFrame(const InstrumentationStackFrame& frame) {
-    instrumentation_stack_->push_back(frame);
-  }
-
-  InstrumentationStackFrame PopInstrumentationStackFrame() {
-    InstrumentationStackFrame frame = instrumentation_stack_->front();
-    instrumentation_stack_->pop_front();
-    return frame;
-  }
-
   BaseMutex* GetHeldMutex(LockLevel level) const {
     return held_mutexes_[level];
   }
@@ -598,13 +577,15 @@
   void CreatePeer(const char* name, bool as_daemon, jobject thread_group);
   friend class Runtime; // For CreatePeer.
 
-  // Avoid use, callers should use SetState. Used only by SignalCatcher::HandleSigQuit and ~Thread.
+  // Avoid use, callers should use SetState. Used only by SignalCatcher::HandleSigQuit, ~Thread and
+  // Dbg::Disconnected.
   ThreadState SetStateUnsafe(ThreadState new_state) {
     ThreadState old_state = GetState();
     state_and_flags_.as_struct.state = new_state;
     return old_state;
   }
   friend class SignalCatcher;  // For SetStateUnsafe.
+  friend class Dbg;  // For SetStateUnsafe.
 
   void VerifyStackImpl() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
@@ -710,6 +691,8 @@
   // System thread id.
   pid_t tid_;
 
+  ThrowLocation throw_location_;
+
   // Guards the 'interrupted_' and 'wait_monitor_' members.
   mutable Mutex* wait_mutex_ DEFAULT_MUTEX_ACQUIRED_AFTER;
   ConditionVariable* wait_cond_ GUARDED_BY(wait_mutex_);
@@ -755,7 +738,7 @@
 
   // Additional stack used by method instrumentation to store method and return pc values.
   // Stored as a pointer since std::deque is not PACKED.
-  std::deque<InstrumentationStackFrame>* instrumentation_stack_;
+  std::deque<instrumentation::InstrumentationStackFrame>* instrumentation_stack_;
 
   // A cached copy of the java.lang.Thread's name.
   std::string* name_;
diff --git a/src/throw_location.cc b/src/throw_location.cc
new file mode 100644
index 0000000..84d2c9b
--- /dev/null
+++ b/src/throw_location.cc
@@ -0,0 +1,41 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "throw_location.h"
+
+#include "mirror/abstract_method-inl.h"
+#include "mirror/class-inl.h"
+#include "mirror/object-inl.h"
+#include "object_utils.h"
+#include "utils.h"
+
+namespace art {
+
+std::string ThrowLocation::Dump() const {
+  return StringPrintf("%s:%d", PrettyMethod(method_).c_str(),
+                      MethodHelper(method_).GetLineNumFromDexPC(dex_pc_));
+}
+
+void ThrowLocation::VisitRoots(RootVisitor* visitor, void* arg) {
+  if (this_object_ != NULL) {
+    visitor(this_object_, arg);
+  }
+  if (method_ != NULL) {
+    visitor(method_, arg);
+  }
+}
+
+}  // namespace art
diff --git a/src/throw_location.h b/src/throw_location.h
new file mode 100644
index 0000000..8c1b941
--- /dev/null
+++ b/src/throw_location.h
@@ -0,0 +1,78 @@
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ART_SRC_THROW_LOCATION_H_
+#define ART_SRC_THROW_LOCATION_H_
+
+#include "base/macros.h"
+#include "root_visitor.h"
+
+#include <stdint.h>
+#include <string>
+
+namespace art {
+
+namespace mirror {
+class AbstractMethod;
+class Object;
+}  // mirror
+
+class PACKED(4) ThrowLocation {
+ public:
+  ThrowLocation() {
+    Clear();
+  }
+
+  ThrowLocation(mirror::Object* throw_this_object, mirror::AbstractMethod* throw_method,
+                uint32_t throw_dex_pc) :
+      this_object_(throw_this_object),
+      method_(throw_method),
+      dex_pc_(throw_dex_pc) {}
+
+  mirror::Object* GetThis() const {
+    return this_object_;
+  }
+
+  mirror::AbstractMethod* GetMethod() const {
+    return method_;
+  }
+
+  uint32_t GetDexPc() const {
+    return dex_pc_;
+  }
+
+  void Clear() {
+    this_object_ = NULL;
+    method_ = NULL;
+    dex_pc_ = -1;
+  }
+
+  std::string Dump() const SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+
+  void VisitRoots(RootVisitor* visitor, void* arg);
+
+ private:
+  // The 'this' reference of the throwing method.
+  mirror::Object* this_object_;
+  // The throwing method.
+  mirror::AbstractMethod* method_;
+  // The instruction within the throwing method.
+  uint32_t dex_pc_;
+};
+
+}  // namespace art
+
+#endif  // ART_SRC_THROW_LOCATION_H_
diff --git a/src/trace.cc b/src/trace.cc
index 859f523..3293290 100644
--- a/src/trace.cc
+++ b/src/trace.cc
@@ -20,6 +20,7 @@
 
 #include "base/unix_file/fd_file.h"
 #include "class_linker.h"
+#include "common_throws.h"
 #include "debugger.h"
 #include "dex_file-inl.h"
 #include "instrumentation.h"
@@ -73,7 +74,14 @@
 //
 // All values are stored in little-endian order.
 
-static const uint32_t kTraceMethodActionMask      = 0x03; // two bits
+enum TraceAction {
+    kTraceMethodEnter = 0x00,      // method entry
+    kTraceMethodExit = 0x01,       // method exit
+    kTraceUnroll = 0x02,     // method exited by exception unrolling
+    // 0x03 currently unused
+    kTraceMethodActionMask = 0x03, // two bits
+};
+
 static const char     kTraceTokenChar             = '*';
 static const uint16_t kTraceHeaderLength          = 32;
 static const uint32_t kTraceMagicValue            = 0x574f4c53;
@@ -82,34 +90,57 @@
 static const uint16_t kTraceRecordSizeSingleClock = 10; // using v2
 static const uint16_t kTraceRecordSizeDualClock   = 14; // using v3 with two timestamps
 
-static ProfilerClockSource gDefaultTraceClockSource = kProfilerClockSourceDual;
+#if defined(HAVE_POSIX_CLOCKS)
+ProfilerClockSource Trace::default_clock_source_ = kProfilerClockSourceDual;
+#else
+ProfilerClockSource Trace::default_clock_source_ = kProfilerClockSourceWall;
+#endif
 
-static inline uint32_t TraceMethodId(uint32_t methodValue) {
-  return (methodValue & ~kTraceMethodActionMask);
+Trace* Trace::the_trace_ = NULL;
+
+static mirror::AbstractMethod* DecodeTraceMethodId(uint32_t tmid) {
+  return reinterpret_cast<mirror::AbstractMethod*>(tmid & ~kTraceMethodActionMask);
 }
 
-static inline uint32_t TraceMethodCombine(uint32_t method, uint8_t traceEvent) {
-  return (method | traceEvent);
+static TraceAction DecodeTraceAction(uint32_t tmid) {
+  return static_cast<TraceAction>(tmid & kTraceMethodActionMask);
+}
+
+static uint32_t EncodeTraceMethodAndAction(const mirror::AbstractMethod* method,
+                                           TraceAction action) {
+  uint32_t tmid = reinterpret_cast<uint32_t>(method) | action;
+  DCHECK_EQ(method, DecodeTraceMethodId(tmid));
+  return tmid;
 }
 
 void Trace::SetDefaultClockSource(ProfilerClockSource clock_source) {
-  gDefaultTraceClockSource = clock_source;
+#if defined(HAVE_POSIX_CLOCKS)
+  default_clock_source_ = clock_source;
+#else
+  if (clock_source != kProfilerClockSourceWall) {
+    LOG(WARNING) << "Ignoring tracing request to use ";
+  }
+#endif
+}
+
+static uint16_t GetTraceVersion(ProfilerClockSource clock_source) {
+  return (clock_source == kProfilerClockSourceDual) ? kTraceVersionDualClock
+                                                    : kTraceVersionSingleClock;
+}
+
+static uint16_t GetRecordSize(ProfilerClockSource clock_source) {
+  return (clock_source == kProfilerClockSourceDual) ? kTraceRecordSizeDualClock
+                                                    : kTraceRecordSizeSingleClock;
 }
 
 bool Trace::UseThreadCpuClock() {
-#if defined(HAVE_POSIX_CLOCKS)
-  return clock_source_ != kProfilerClockSourceWall;
-#else
-  return false;
-#endif
+  return (clock_source_ == kProfilerClockSourceThreadCpu) ||
+      (clock_source_ == kProfilerClockSourceDual);
 }
 
 bool Trace::UseWallClock() {
-#if defined(HAVE_POSIX_CLOCKS)
-  return clock_source_ != kProfilerClockSourceThreadCpu;
-#else
-  return true;
-#endif
+  return (clock_source_ == kProfilerClockSourceWall) ||
+      (clock_source_ == kProfilerClockSourceDual);
 }
 
 static void MeasureClockOverhead(Trace* trace) {
@@ -165,109 +196,129 @@
   *buf++ = (uint8_t) (val >> 56);
 }
 
-Trace::Trace(File* trace_file, int buffer_size, int flags)
-    : trace_file_(trace_file), buf_(new uint8_t[buffer_size]()), flags_(flags),
-      clock_source_(gDefaultTraceClockSource), overflow_(false),
-      buffer_size_(buffer_size), start_time_(0), trace_version_(0), record_size_(0), cur_offset_(0) {
-}
-
-void Trace::Start(const char* trace_filename, int trace_fd, int buffer_size, int flags, bool direct_to_ddms) {
-  if (Runtime::Current()->IsMethodTracingActive()) {
-    LOG(INFO) << "Trace already in progress, ignoring this request";
-    return;
+void Trace::Start(const char* trace_filename, int trace_fd, int buffer_size, int flags,
+                  bool direct_to_ddms) {
+  Thread* self = Thread::Current();
+  {
+    MutexLock mu(self, *Locks::trace_lock_);
+    if (the_trace_ != NULL) {
+      LOG(ERROR) << "Trace already in progress, ignoring this request";
+      return;
+    }
   }
-
-  Runtime::Current()->GetThreadList()->SuspendAll();
+  Runtime* runtime = Runtime::Current();
+  runtime->GetThreadList()->SuspendAll();
 
   // Open trace file if not going directly to ddms.
-  File* trace_file = NULL;
+  UniquePtr<File> trace_file;
   if (!direct_to_ddms) {
     if (trace_fd < 0) {
-      trace_file = OS::OpenFile(trace_filename, true);
+      trace_file.reset(OS::OpenFile(trace_filename, true));
     } else {
-      trace_file = new File(trace_fd, "tracefile");
+      trace_file.reset(new File(trace_fd, "tracefile"));
       trace_file->DisableAutoClose();
     }
-    if (trace_file == NULL) {
+    if (trace_file.get() == NULL) {
       PLOG(ERROR) << "Unable to open trace file '" << trace_filename << "'";
-      Thread::Current()->ThrowNewException("Ljava/lang/RuntimeException;",
-          StringPrintf("Unable to open trace file '%s'", trace_filename).c_str());
-      Runtime::Current()->GetThreadList()->ResumeAll();
+      runtime->GetThreadList()->ResumeAll();
+      ScopedObjectAccess soa(self);
+      ThrowRuntimeException("Unable to open trace file '%s'", trace_filename);
       return;
     }
   }
 
   // Create Trace object.
-  Trace* tracer(new Trace(trace_file, buffer_size, flags));
+  {
+    MutexLock mu(self, *Locks::trace_lock_);
+    if(the_trace_ != NULL) {
+      LOG(ERROR) << "Trace already in progress, ignoring this request";
+    } else {
+      the_trace_ = new Trace(trace_file.release(), buffer_size, flags);
 
-  // Enable count of allocs if specified in the flags.
-  if ((flags && kTraceCountAllocs) != 0) {
-    Runtime::Current()->SetStatsEnabled(true);
+      // Enable count of allocs if specified in the flags.
+      if ((flags && kTraceCountAllocs) != 0) {
+        runtime->SetStatsEnabled(true);
+      }
+
+      runtime->GetInstrumentation()->AddListener(the_trace_,
+                                                 instrumentation::Instrumentation::kMethodEntered |
+                                                 instrumentation::Instrumentation::kMethodExited |
+                                                 instrumentation::Instrumentation::kMethodUnwind);
+    }
   }
-
-  Runtime::Current()->EnableMethodTracing(tracer);
-  tracer->BeginTracing();
-
-  Runtime::Current()->GetThreadList()->ResumeAll();
+  runtime->GetThreadList()->ResumeAll();
 }
 
 void Trace::Stop() {
-  if (!Runtime::Current()->IsMethodTracingActive()) {
-    LOG(INFO) << "Trace stop requested, but no trace currently running";
-    return;
+  Runtime* runtime = Runtime::Current();
+  runtime->GetThreadList()->SuspendAll();
+  Trace* the_trace = NULL;
+  {
+    MutexLock mu(Thread::Current(), *Locks::trace_lock_);
+    if (the_trace_ == NULL) {
+      LOG(ERROR) << "Trace stop requested, but no trace currently running";
+    } else {
+      the_trace = the_trace_;
+      the_trace_ = NULL;
+    }
   }
-
-  Runtime::Current()->GetThreadList()->SuspendAll();
-
-  Runtime::Current()->GetInstrumentation()->GetTrace()->FinishTracing();
-  Runtime::Current()->DisableMethodTracing();
-
-  Runtime::Current()->GetThreadList()->ResumeAll();
+  if (the_trace != NULL) {
+    the_trace->FinishTracing();
+    runtime->GetInstrumentation()->RemoveListener(the_trace,
+                                                  instrumentation::Instrumentation::kMethodEntered |
+                                                  instrumentation::Instrumentation::kMethodExited |
+                                                  instrumentation::Instrumentation::kMethodUnwind);
+    delete the_trace;
+  }
+  runtime->GetThreadList()->ResumeAll();
 }
 
 void Trace::Shutdown() {
-  if (!Runtime::Current()->IsMethodTracingActive()) {
-    LOG(INFO) << "Trace shutdown requested, but no trace currently running";
-    return;
+  if (IsMethodTracingActive()) {
+    Stop();
   }
-  Runtime::Current()->GetInstrumentation()->GetTrace()->FinishTracing();
-  Runtime::Current()->DisableMethodTracing();
 }
 
-void Trace::BeginTracing() {
-  // Set the start time of tracing.
-  start_time_ = MicroTime();
+bool Trace::IsMethodTracingActive() {
+  MutexLock mu(Thread::Current(), *Locks::trace_lock_);
+  return the_trace_ != NULL;
+}
 
-  // Set trace version and record size.
-  if (UseThreadCpuClock() && UseWallClock()) {
-    trace_version_ = kTraceVersionDualClock;
-    record_size_ = kTraceRecordSizeDualClock;
-  } else {
-    trace_version_ = kTraceVersionSingleClock;
-    record_size_ = kTraceRecordSizeSingleClock;
-  }
-
+Trace::Trace(File* trace_file, int buffer_size, int flags)
+    : trace_file_(trace_file), buf_(new uint8_t[buffer_size]()), flags_(flags),
+      clock_source_(default_clock_source_), buffer_size_(buffer_size), start_time_(MicroTime()),
+      cur_offset_(0),  overflow_(false) {
   // Set up the beginning of the trace.
+  uint16_t trace_version = GetTraceVersion(clock_source_);
   memset(buf_.get(), 0, kTraceHeaderLength);
   Append4LE(buf_.get(), kTraceMagicValue);
-  Append2LE(buf_.get() + 4, trace_version_);
+  Append2LE(buf_.get() + 4, trace_version);
   Append2LE(buf_.get() + 6, kTraceHeaderLength);
   Append8LE(buf_.get() + 8, start_time_);
-  if (trace_version_ >= kTraceVersionDualClock) {
-    Append2LE(buf_.get() + 16, record_size_);
+  if (trace_version >= kTraceVersionDualClock) {
+    uint16_t record_size = GetRecordSize(clock_source_);
+    Append2LE(buf_.get() + 16, record_size);
   }
 
   // Update current offset.
   cur_offset_ = kTraceHeaderLength;
+}
 
-  // Install all method tracing stubs.
-  Runtime::Current()->GetInstrumentation()->InstallStubs();
+static void DumpBuf(uint8_t* buf, size_t buf_size, ProfilerClockSource clock_source)
+    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+  uint8_t* ptr = buf + kTraceHeaderLength;
+  uint8_t* end = buf + buf_size;
+
+  while (ptr < end) {
+    uint32_t tmid = ptr[2] | (ptr[3] << 8) | (ptr[4] << 16) | (ptr[5] << 24);
+    mirror::AbstractMethod* method = DecodeTraceMethodId(tmid);
+    TraceAction action = DecodeTraceAction(tmid);
+    LOG(INFO) << PrettyMethod(method) << " " << static_cast<int>(action);
+    ptr += GetRecordSize(clock_source);
+  }
 }
 
 void Trace::FinishTracing() {
-  // Uninstall all method tracing stubs.
-  Runtime::Current()->GetInstrumentation()->UninstallStubs();
-
   // Compute elapsed time.
   uint64_t elapsed = MicroTime() - start_time_;
 
@@ -278,12 +329,13 @@
     Runtime::Current()->SetStatsEnabled(false);
   }
 
-  GetVisitedMethods(final_offset);
+  std::set<mirror::AbstractMethod*> visited_methods;
+  GetVisitedMethods(final_offset, &visited_methods);
 
   std::ostringstream os;
 
   os << StringPrintf("%cversion\n", kTraceTokenChar);
-  os << StringPrintf("%d\n", trace_version_);
+  os << StringPrintf("%d\n", GetTraceVersion(clock_source_));
   os << StringPrintf("data-file-overflow=%s\n", overflow_ ? "true" : "false");
   if (UseThreadCpuClock()) {
     if (UseWallClock()) {
@@ -295,7 +347,8 @@
     os << StringPrintf("clock=wall\n");
   }
   os << StringPrintf("elapsed-time-usec=%llu\n", elapsed);
-  os << StringPrintf("num-method-calls=%zd\n", (final_offset - kTraceHeaderLength) / record_size_);
+  size_t num_records = (final_offset - kTraceHeaderLength) / GetRecordSize(clock_source_);
+  os << StringPrintf("num-method-calls=%zd\n", num_records);
   os << StringPrintf("clock-call-overhead-nsec=%d\n", clock_overhead);
   os << StringPrintf("vm=art\n");
   if ((flags_ & kTraceCountAllocs) != 0) {
@@ -306,7 +359,7 @@
   os << StringPrintf("%cthreads\n", kTraceTokenChar);
   DumpThreadList(os);
   os << StringPrintf("%cmethods\n", kTraceTokenChar);
-  DumpMethodList(os);
+  DumpMethodList(os, visited_methods);
   os << StringPrintf("%cend\n", kTraceTokenChar);
 
   std::string header(os.str());
@@ -317,74 +370,128 @@
     iov[1].iov_base = buf_.get();
     iov[1].iov_len = final_offset;
     Dbg::DdmSendChunkV(CHUNK_TYPE("MPSE"), iov, 2);
+    const bool kDumpTraceInfo = false;
+    if (kDumpTraceInfo) {
+      LOG(INFO) << "Trace sent:\n" << header;
+      DumpBuf(buf_.get(), final_offset, clock_source_);
+    }
   } else {
     if (!trace_file_->WriteFully(header.c_str(), header.length()) ||
         !trace_file_->WriteFully(buf_.get(), final_offset)) {
       std::string detail(StringPrintf("Trace data write failed: %s", strerror(errno)));
       PLOG(ERROR) << detail;
-      Thread::Current()->ThrowNewException("Ljava/lang/RuntimeException;", detail.c_str());
+      ThrowRuntimeException("%s", detail.c_str());
     }
   }
 }
 
-void Trace::LogMethodTraceEvent(Thread* self, const mirror::AbstractMethod* method,
-                                Trace::TraceEvent event) {
-  if (thread_clock_base_map_.find(self) == thread_clock_base_map_.end()) {
-    uint64_t time = ThreadCpuMicroTime();
-    thread_clock_base_map_.Put(self, time);
-  }
+void Trace::DexPcMoved(Thread* thread, mirror::Object* this_object,
+                       const mirror::AbstractMethod* method, uint32_t new_dex_pc) {
+  // We're not recorded to listen to this kind of event, so complain.
+  LOG(ERROR) << "Unexpected dex PC event in tracing " << PrettyMethod(method) << " " << new_dex_pc;
+};
 
+void Trace::MethodEntered(Thread* thread, mirror::Object* this_object,
+                          const mirror::AbstractMethod* method, uint32_t dex_pc) {
+  LogMethodTraceEvent(thread, method, instrumentation::Instrumentation::kMethodEntered);
+}
+
+void Trace::MethodExited(Thread* thread, mirror::Object* this_object,
+                         const mirror::AbstractMethod* method, uint32_t dex_pc,
+                         const JValue& return_value) {
+  UNUSED(return_value);
+  LogMethodTraceEvent(thread, method, instrumentation::Instrumentation::kMethodExited);
+}
+
+void Trace::MethodUnwind(Thread* thread, const mirror::AbstractMethod* method, uint32_t dex_pc) {
+  LogMethodTraceEvent(thread, method, instrumentation::Instrumentation::kMethodUnwind);
+}
+
+void Trace::ExceptionCaught(Thread* thread, const ThrowLocation& throw_location,
+                            mirror::AbstractMethod* catch_method, uint32_t catch_dex_pc,
+                            mirror::Throwable* exception_object)
+    SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) {
+  LOG(ERROR) << "Unexpected exception caught event in tracing";
+}
+
+void Trace::LogMethodTraceEvent(Thread* thread, const mirror::AbstractMethod* method,
+                                instrumentation::Instrumentation::InstrumentationEvent event) {
   // Advance cur_offset_ atomically.
   int32_t new_offset;
   int32_t old_offset;
   do {
     old_offset = cur_offset_;
-    new_offset = old_offset + record_size_;
+    new_offset = old_offset + GetRecordSize(clock_source_);
     if (new_offset > buffer_size_) {
       overflow_ = true;
       return;
     }
   } while (android_atomic_release_cas(old_offset, new_offset, &cur_offset_) != 0);
 
-  uint32_t method_value = TraceMethodCombine(reinterpret_cast<uint32_t>(method), event);
+  TraceAction action = kTraceMethodEnter;
+  switch (event) {
+    case instrumentation::Instrumentation::kMethodEntered:
+      action = kTraceMethodEnter;
+      break;
+    case instrumentation::Instrumentation::kMethodExited:
+      action = kTraceMethodExit;
+      break;
+    case instrumentation::Instrumentation::kMethodUnwind:
+      action = kTraceUnroll;
+      break;
+    default:
+      UNIMPLEMENTED(FATAL) << "Unexpected event: " << event;
+  }
+
+  uint32_t method_value = EncodeTraceMethodAndAction(method, action);
 
   // Write data
   uint8_t* ptr = buf_.get() + old_offset;
-  Append2LE(ptr, self->GetTid());
+  Append2LE(ptr, thread->GetTid());
   Append4LE(ptr + 2, method_value);
   ptr += 6;
 
   if (UseThreadCpuClock()) {
-    uint64_t thread_clock_base = thread_clock_base_map_.find(self)->second;
-    uint32_t thread_clock_diff = ThreadCpuMicroTime() - thread_clock_base;
+    // TODO: this isn't vaguely thread safe.
+    SafeMap<Thread*, uint64_t>::iterator it = thread_clock_base_map_.find(thread);
+    uint32_t thread_clock_diff = 0;
+    if (UNLIKELY(it == thread_clock_base_map_.end())) {
+      // First event, the diff is 0, record the base time in the map.
+      uint64_t time = ThreadCpuMicroTime();
+      thread_clock_base_map_.Put(thread, time);
+    } else {
+      uint64_t thread_clock_base = it->second;
+      thread_clock_diff = ThreadCpuMicroTime() - thread_clock_base;
+    }
     Append4LE(ptr, thread_clock_diff);
     ptr += 4;
   }
-
   if (UseWallClock()) {
     uint32_t wall_clock_diff = MicroTime() - start_time_;
     Append4LE(ptr, wall_clock_diff);
   }
 }
 
-void Trace::GetVisitedMethods(size_t end_offset) {
+void Trace::GetVisitedMethods(size_t buf_size,
+                              std::set<mirror::AbstractMethod*>* visited_methods) {
   uint8_t* ptr = buf_.get() + kTraceHeaderLength;
-  uint8_t* end = buf_.get() + end_offset;
+  uint8_t* end = buf_.get() + buf_size;
 
   while (ptr < end) {
-    uint32_t method_value = ptr[2] | (ptr[3] << 8) | (ptr[4] << 16) | (ptr[5] << 24);
-    mirror::AbstractMethod* method =
-        reinterpret_cast<mirror::AbstractMethod*>(TraceMethodId(method_value));
-    visited_methods_.insert(method);
-    ptr += record_size_;
+    uint32_t tmid = ptr[2] | (ptr[3] << 8) | (ptr[4] << 16) | (ptr[5] << 24);
+    mirror::AbstractMethod* method = DecodeTraceMethodId(tmid);
+    visited_methods->insert(method);
+    ptr += GetRecordSize(clock_source_);
   }
 }
 
-void Trace::DumpMethodList(std::ostream& os) {
-  typedef std::set<const mirror::AbstractMethod*>::const_iterator It; // TODO: C++0x auto
-  for (It it = visited_methods_.begin(); it != visited_methods_.end(); ++it) {
-    const mirror::AbstractMethod* method = *it;
-    MethodHelper mh(method);
+void Trace::DumpMethodList(std::ostream& os,
+                           const std::set<mirror::AbstractMethod*>& visited_methods) {
+  typedef std::set<mirror::AbstractMethod*>::const_iterator It; // TODO: C++0x auto
+  MethodHelper mh;
+  for (It it = visited_methods.begin(); it != visited_methods.end(); ++it) {
+    mirror::AbstractMethod* method = *it;
+    mh.ChangeMethod(method);
     os << StringPrintf("%p\t%s\t%s\t%s\t%s\n", method,
         PrettyDescriptor(mh.GetDeclaringClassDescriptor()).c_str(), mh.GetName(),
         mh.GetSignature().c_str(), mh.GetDeclaringClassSourceFile());
diff --git a/src/trace.h b/src/trace.h
index 1be1cc4..9432e71 100644
--- a/src/trace.h
+++ b/src/trace.h
@@ -23,6 +23,7 @@
 
 #include "base/macros.h"
 #include "globals.h"
+#include "instrumentation.h"
 #include "os.h"
 #include "safe_map.h"
 #include "UniquePtr.h"
@@ -37,45 +38,65 @@
 enum ProfilerClockSource {
   kProfilerClockSourceThreadCpu,
   kProfilerClockSourceWall,
-  kProfilerClockSourceDual,
+  kProfilerClockSourceDual,  // Both wall and thread CPU clocks.
 };
 
-class Trace {
+class Trace : public instrumentation::InstrumentationListener {
  public:
-  enum TraceEvent {
-    kMethodTraceEnter = 0,
-    kMethodTraceExit = 1,
-    kMethodTraceUnwind = 2,
-  };
-
   enum TraceFlag {
     kTraceCountAllocs = 1,
   };
 
   static void SetDefaultClockSource(ProfilerClockSource clock_source);
 
-  static void Start(const char* trace_filename, int trace_fd, int buffer_size, int flags, bool direct_to_ddms);
-  static void Stop();
-  static void Shutdown() NO_THREAD_SAFETY_ANALYSIS;  // TODO: implement appropriate locking.
+  static void Start(const char* trace_filename, int trace_fd, int buffer_size, int flags,
+                    bool direct_to_ddms)
+  LOCKS_EXCLUDED(Locks::mutator_lock_,
+                 Locks::thread_list_lock_,
+                 Locks::thread_suspend_count_lock_,
+                 Locks::trace_lock_);
+  static void Stop() LOCKS_EXCLUDED(Locks::trace_lock_);
+  static void Shutdown() LOCKS_EXCLUDED(Locks::trace_lock_);
+  static bool IsMethodTracingActive() LOCKS_EXCLUDED(Locks::trace_lock_);
 
   bool UseWallClock();
   bool UseThreadCpuClock();
 
-  void LogMethodTraceEvent(Thread* self, const mirror::AbstractMethod* method, TraceEvent event);
-
+  virtual void MethodEntered(Thread* thread, mirror::Object* this_object,
+                             const mirror::AbstractMethod* method, uint32_t dex_pc)
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+  virtual void MethodExited(Thread* thread, mirror::Object* this_object,
+                            const mirror::AbstractMethod* method, uint32_t dex_pc,
+                            const JValue& return_value)
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+  virtual void MethodUnwind(Thread* thread, const mirror::AbstractMethod* method, uint32_t dex_pc)
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+  virtual void DexPcMoved(Thread* thread, mirror::Object* this_object,
+                          const mirror::AbstractMethod* method, uint32_t new_dex_pc)
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+  virtual void ExceptionCaught(Thread* thread, const ThrowLocation& throw_location,
+                               mirror::AbstractMethod* catch_method, uint32_t catch_dex_pc,
+                               mirror::Throwable* exception_object)
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
  private:
   explicit Trace(File* trace_file, int buffer_size, int flags);
 
-  void BeginTracing();
   void FinishTracing() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
 
+  void LogMethodTraceEvent(Thread* thread, const mirror::AbstractMethod* method,
+                           instrumentation::Instrumentation::InstrumentationEvent event);
+
   // Methods to output traced methods and threads.
-  void GetVisitedMethods(size_t end_offset);
-  void DumpMethodList(std::ostream& os) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
+  void GetVisitedMethods(size_t end_offset, std::set<mirror::AbstractMethod*>* visited_methods);
+  void DumpMethodList(std::ostream& os, const std::set<mirror::AbstractMethod*>& visited_methods)
+      SHARED_LOCKS_REQUIRED(Locks::mutator_lock_);
   void DumpThreadList(std::ostream& os) LOCKS_EXCLUDED(Locks::thread_list_lock_);
 
-  // Set of methods visited by the profiler.
-  std::set<const mirror::AbstractMethod*> visited_methods_;
+  // Singleton instance of the Trace or NULL when no method tracing is active.
+  static Trace* the_trace_ GUARDED_BY(Locks::trace_lock_);
+
+  // The default profiler clock source.
+  static ProfilerClockSource default_clock_source_;
 
   // Maps a thread to its clock base.
   SafeMap<Thread*, uint64_t> thread_clock_base_map_;
@@ -87,18 +108,22 @@
   UniquePtr<uint8_t> buf_;
 
   // Flags enabling extra tracing of things such as alloc counts.
-  int flags_;
+  const int flags_;
 
-  ProfilerClockSource clock_source_;
+  const ProfilerClockSource clock_source_;
 
-  bool overflow_;
-  int buffer_size_;
-  uint64_t start_time_;
-  uint16_t trace_version_;
-  uint16_t record_size_;
+  // Size of buf_.
+  const int buffer_size_;
 
+  // Time trace was created.
+  const uint64_t start_time_;
+
+  // Offset into buf_.
   volatile int32_t cur_offset_;
 
+  // Did we overflow the buffer recording traces?
+  bool overflow_;
+
   DISALLOW_COPY_AND_ASSIGN(Trace);
 };
 
diff --git a/src/verifier/reg_type_cache.cc b/src/verifier/reg_type_cache.cc
index c7a1b4f..6228ba5 100644
--- a/src/verifier/reg_type_cache.cc
+++ b/src/verifier/reg_type_cache.cc
@@ -148,6 +148,10 @@
     klass = class_linker->FindClass(descriptor.c_str(), loader);
   } else {
     klass = class_linker->LookupClass(descriptor.c_str(), loader);
+    if (klass != NULL && !klass->IsLoaded()) {
+      // We found the class but without it being loaded its not safe for use.
+      klass = NULL;
+    }
   }
   return klass;
 }
@@ -244,12 +248,12 @@
 RegTypeCache::~RegTypeCache() {
   CHECK_LE(primitive_count_, entries_.size());
   // Delete only the non primitive types.
-  if (primitive_count_  == static_cast<uint16_t>(entries_.size())) {
+  if (entries_.size() == kNumPrimitives) {
     // All entries are primitive, nothing to delete.
     return;
   }
   std::vector<RegType*>::iterator non_primitive_begin = entries_.begin();
-  std::advance(non_primitive_begin, primitive_count_);
+  std::advance(non_primitive_begin, kNumPrimitives);
   STLDeleteContainerPointers(non_primitive_begin, entries_.end());
 }
 
@@ -267,8 +271,8 @@
     FloatType::GetInstance();
     DoubleLoType::Destroy();
     DoubleHiType::Destroy();
-   RegTypeCache::primitive_initialized_ = false;
-   RegTypeCache::primitive_count_ = 0;
+    RegTypeCache::primitive_initialized_ = false;
+    RegTypeCache::primitive_count_ = 0;
   }
 }
 
diff --git a/src/verifier/reg_type_cache.h b/src/verifier/reg_type_cache.h
index cacd517..41d3c69 100644
--- a/src/verifier/reg_type_cache.h
+++ b/src/verifier/reg_type_cache.h
@@ -35,6 +35,7 @@
 
 class RegType;
 
+const size_t kNumPrimitives = 12;
 class RegTypeCache {
  public:
   explicit RegTypeCache(bool can_load_classes) : can_load_classes_(can_load_classes) {
@@ -45,7 +46,7 @@
     if(!RegTypeCache::primitive_initialized_) {
       CHECK_EQ(RegTypeCache::primitive_count_, 0);
       CreatePrimitiveTypes();
-      CHECK_EQ(RegTypeCache::primitive_count_, 12);
+      CHECK_EQ(RegTypeCache::primitive_count_, kNumPrimitives);
       RegTypeCache::primitive_initialized_ = true;
     }
   }
diff --git a/test/003-omnibus-opcodes/expected.txt b/test/003-omnibus-opcodes/expected.txt
index c5e67e5..a62c498 100644
--- a/test/003-omnibus-opcodes/expected.txt
+++ b/test/003-omnibus-opcodes/expected.txt
@@ -70,14 +70,6 @@
 UnresTest1...
 UnresTest1...
 UnresTest2...
-java.lang.NoClassDefFoundError: Failed resolution of: LUnresClass;
-	at UnresTest2.run(UnresTest2.java:33)
-	at Main.run(Main.java:64)
-	at Main.main(Main.java:26)
-java.lang.NoClassDefFoundError: Failed resolution of: LUnresClassSubclass;
-	at UnresTest2.run(UnresTest2.java:41)
-	at Main.run(Main.java:64)
-	at Main.main(Main.java:26)
 UnresTest2 done
 InternedString.run
 Done!
diff --git a/test/003-omnibus-opcodes/src/UnresTest2.java b/test/003-omnibus-opcodes/src/UnresTest2.java
index c94f226..4135d73 100644
--- a/test/003-omnibus-opcodes/src/UnresTest2.java
+++ b/test/003-omnibus-opcodes/src/UnresTest2.java
@@ -33,22 +33,23 @@
             un = new UnresClass();
             Main.assertTrue(false);
         } catch (NoClassDefFoundError ncdfe) {
-          ncdfe.printStackTrace();
+            Main.assertTrue(ncdfe.getCause() instanceof ClassNotFoundException);
             // good
         }
 
         try {
-          new UnresClassSubclass();
-          Main.assertTrue(false);
+            new UnresClassSubclass();
+            Main.assertTrue(false);
         } catch (NoClassDefFoundError ncdfe) {
-          ncdfe.printStackTrace();
-          // good
+            Main.assertTrue(ncdfe.getCause() instanceof ClassNotFoundException);
+            // good
         }
 
         try {
             UnresClass[] uar = new UnresClass[3];
             Main.assertTrue(false);
         } catch (NoClassDefFoundError ncdfe) {
+            Main.assertTrue(ncdfe.getCause() instanceof ClassNotFoundException);
             // good
         }
 
diff --git a/test/044-proxy/src/ReturnsAndArgPassing.java b/test/044-proxy/src/ReturnsAndArgPassing.java
index 50eff77..a173410 100644
--- a/test/044-proxy/src/ReturnsAndArgPassing.java
+++ b/test/044-proxy/src/ReturnsAndArgPassing.java
@@ -51,6 +51,8 @@
   static int barInvocations = 0;
 
   static class MyInvocationHandler implements InvocationHandler {
+    boolean causeNpeOnReturn = false;
+    Class<?> returnType = null;
     public Object invoke(Object proxy, Method method, Object[] args) {
       check(proxy instanceof Proxy);
       check(method.getDeclaringClass() == MyInterface.class);
@@ -62,30 +64,29 @@
         check(args == null);
         barInvocations++;
       }
-      if      (name.equals("voidFoo"))    { return null; }
-      else if (name.equals("voidBar"))    { return null; }
-      else if (name.equals("booleanFoo")) { return true; }
-      else if (name.equals("booleanBar")) { return false; }
-      else if (name.equals("byteFoo"))    { return Byte.MAX_VALUE; }
-      else if (name.equals("byteBar"))    { return Byte.MIN_VALUE; }
-      else if (name.equals("charFoo"))    { return Character.MAX_VALUE; }
-      else if (name.equals("charBar"))    { return Character.MIN_VALUE; }
-      else if (name.equals("shortFoo"))   { return Short.MAX_VALUE; }
-      else if (name.equals("shortBar"))   { return Short.MIN_VALUE; }
-      else if (name.equals("intFoo"))     { return Integer.MAX_VALUE; }
-      else if (name.equals("intBar"))     { return Integer.MIN_VALUE; }
-      else if (name.equals("longFoo"))    { return Long.MAX_VALUE; }
-      else if (name.equals("longBar"))    { return Long.MIN_VALUE; }
-      else if (name.equals("floatFoo"))   { return Float.MAX_VALUE; }
-      else if (name.equals("floatBar"))   { return Float.MIN_VALUE; }
-      else if (name.equals("doubleFoo"))  { return Double.MAX_VALUE; }
-      else if (name.equals("doubleBar"))  { return Double.MIN_VALUE; }
-      else if (name.equals("selectArg")) {
+      if (causeNpeOnReturn) {
+        return null;
+      } else if (name.equals("voidFoo") || name.equals("voidBar")) {
+        return null;
+      } else if (name.equals("booleanFoo")) {
+        return true;
+      } else if (name.equals("booleanBar")) {
+        return false;
+      } else if (name.equals("selectArg")) {
         check(args.length == 6);
         int select = (Integer)args[0];
         return args[select];
       } else {
-        throw new AssertionError("Unexpect method " + method);
+        try {
+          if (name.endsWith("Foo")) {
+            return returnType.getField("MAX_VALUE").get(null);
+          } else {
+            check(name.endsWith("Bar"));
+            return returnType.getField("MIN_VALUE").get(null);
+          }
+        } catch (Exception e) {
+          throw new Error("return type = " + returnType, e);
+        }
       }
     }
   }
@@ -106,6 +107,7 @@
     check(barInvocations == 1);
 
     check(fooInvocations == 1);
+    myHandler.returnType = Boolean.class;
     check(proxyMyInterface.booleanFoo() == true);
     check(fooInvocations == 2);
 
@@ -114,6 +116,7 @@
     check(barInvocations == 2);
 
     check(fooInvocations == 2);
+    myHandler.returnType = Byte.class;
     check(proxyMyInterface.byteFoo() == Byte.MAX_VALUE);
     check(fooInvocations == 3);
 
@@ -122,6 +125,7 @@
     check(barInvocations == 3);
 
     check(fooInvocations == 3);
+    myHandler.returnType = Character.class;
     check(proxyMyInterface.charFoo() == Character.MAX_VALUE);
     check(fooInvocations == 4);
 
@@ -130,6 +134,7 @@
     check(barInvocations == 4);
 
     check(fooInvocations == 4);
+    myHandler.returnType = Short.class;
     check(proxyMyInterface.shortFoo() == Short.MAX_VALUE);
     check(fooInvocations == 5);
 
@@ -138,6 +143,7 @@
     check(barInvocations == 5);
 
     check(fooInvocations == 5);
+    myHandler.returnType = Integer.class;
     check(proxyMyInterface.intFoo() == Integer.MAX_VALUE);
     check(fooInvocations == 6);
 
@@ -146,6 +152,7 @@
     check(barInvocations == 6);
 
     check(fooInvocations == 6);
+    myHandler.returnType = Long.class;
     check(proxyMyInterface.longFoo() == Long.MAX_VALUE);
     check(fooInvocations == 7);
 
@@ -154,6 +161,7 @@
     check(barInvocations == 7);
 
     check(fooInvocations == 7);
+    myHandler.returnType = Float.class;
     check(proxyMyInterface.floatFoo() == Float.MAX_VALUE);
     check(fooInvocations == 8);
 
@@ -162,6 +170,7 @@
     check(barInvocations == 8);
 
     check(fooInvocations == 8);
+    myHandler.returnType = Double.class;
     check(proxyMyInterface.doubleFoo() == Double.MAX_VALUE);
     check(fooInvocations == 9);
 
@@ -169,6 +178,259 @@
     check(proxyMyInterface.doubleBar() == Double.MIN_VALUE);
     check(barInvocations == 9);
 
+    // Toggle flag to get return values to cause NPEs
+    myHandler.causeNpeOnReturn = true;
+
+    check(fooInvocations == 9);
+    try {
+        proxyMyInterface.booleanFoo();
+        throw new AssertionError("Expected NPE");
+    } catch (NullPointerException e) {
+    }
+    check(fooInvocations == 10);
+
+    check(barInvocations == 9);
+    try {
+        proxyMyInterface.booleanBar();
+        throw new AssertionError("Expected NPE");
+    } catch (NullPointerException e) {
+    }
+    check(barInvocations == 10);
+
+    check(fooInvocations == 10);
+    try {
+        proxyMyInterface.byteFoo();
+        throw new AssertionError("Expected NPE");
+    } catch (NullPointerException e) {
+    }
+    check(fooInvocations == 11);
+
+    check(barInvocations == 10);
+    try {
+        proxyMyInterface.byteBar();
+        throw new AssertionError("Expected NPE");
+    } catch (NullPointerException e) {
+    }
+    check(barInvocations == 11);
+
+    check(fooInvocations == 11);
+    try {
+        proxyMyInterface.charFoo();
+        throw new AssertionError("Expected NPE");
+    } catch (NullPointerException e) {
+    }
+    check(fooInvocations == 12);
+
+    check(barInvocations == 11);
+    try {
+        proxyMyInterface.charBar();
+        throw new AssertionError("Expected NPE");
+    } catch (NullPointerException e) {
+    }
+    check(barInvocations == 12);
+
+    check(fooInvocations == 12);
+    try {
+        proxyMyInterface.shortFoo();
+        throw new AssertionError("Expected NPE");
+    } catch (NullPointerException e) {
+    }
+    check(fooInvocations == 13);
+
+    check(barInvocations == 12);
+    try {
+        proxyMyInterface.shortBar();
+        throw new AssertionError("Expected NPE");
+    } catch (NullPointerException e) {
+    }
+    check(barInvocations == 13);
+
+    check(fooInvocations == 13);
+    try {
+        proxyMyInterface.intFoo();
+        throw new AssertionError("Expected NPE");
+    } catch (NullPointerException e) {
+    }
+    check(fooInvocations == 14);
+
+    check(barInvocations == 13);
+    try {
+        proxyMyInterface.intBar();
+        throw new AssertionError("Expected NPE");
+    } catch (NullPointerException e) {
+    }
+    check(barInvocations == 14);
+
+    check(fooInvocations == 14);
+    try {
+        proxyMyInterface.longFoo();
+        throw new AssertionError("Expected NPE");
+    } catch (NullPointerException e) {
+    }
+    check(fooInvocations == 15);
+
+    check(barInvocations == 14);
+    try {
+        proxyMyInterface.longBar();
+        throw new AssertionError("Expected NPE");
+    } catch (NullPointerException e) {
+    }
+    check(barInvocations == 15);
+
+    check(fooInvocations == 15);
+    try {
+        proxyMyInterface.floatFoo();
+        throw new AssertionError("Expected NPE");
+    } catch (NullPointerException e) {
+    }
+    check(fooInvocations == 16);
+
+    check(barInvocations == 15);
+    try {
+        proxyMyInterface.floatBar();
+        throw new AssertionError("Expected NPE");
+    } catch (NullPointerException e) {
+    }
+    check(barInvocations == 16);
+
+    check(fooInvocations == 16);
+    try {
+        proxyMyInterface.doubleFoo();
+        throw new AssertionError("Expected NPE");
+    } catch (NullPointerException e) {
+    }
+    check(fooInvocations == 17);
+
+    check(barInvocations == 16);
+    try {
+        proxyMyInterface.doubleBar();
+        throw new AssertionError("Expected NPE");
+    } catch (NullPointerException e) {
+    }
+    check(barInvocations == 17);
+
+    // Toggle flag to stop NPEs
+    myHandler.causeNpeOnReturn = false;
+
+    check(fooInvocations == 17);
+    myHandler.returnType = Double.class;  // Double -> byte == fail
+    try {
+        proxyMyInterface.byteFoo();
+        throw new AssertionError("Expected ClassCastException");
+    } catch (ClassCastException e) {
+    }
+    check(fooInvocations == 18);
+
+    check(barInvocations == 17);
+    try {
+        proxyMyInterface.byteBar();
+        throw new AssertionError("Expected NPE");
+    } catch (ClassCastException e) {
+    }
+    check(barInvocations == 18);
+
+    check(fooInvocations == 18);
+    myHandler.returnType = Float.class;  // Float -> byte == fail
+    try {
+        proxyMyInterface.byteFoo();
+        throw new AssertionError("Expected ClassCastException");
+    } catch (ClassCastException e) {
+    }
+    check(fooInvocations == 19);
+
+    check(barInvocations == 18);
+    try {
+        proxyMyInterface.byteBar();
+        throw new AssertionError("Expected NPE");
+    } catch (ClassCastException e) {
+    }
+    check(barInvocations == 19);
+
+    check(fooInvocations == 19);
+    myHandler.returnType = Long.class;  // Long -> byte == fail
+    try {
+        proxyMyInterface.byteFoo();
+        throw new AssertionError("Expected ClassCastException");
+    } catch (ClassCastException e) {
+    }
+    check(fooInvocations == 20);
+
+    check(barInvocations == 19);
+    try {
+        proxyMyInterface.byteBar();
+        throw new AssertionError("Expected NPE");
+    } catch (ClassCastException e) {
+    }
+    check(barInvocations == 20);
+
+    check(fooInvocations == 20);
+    myHandler.returnType = Integer.class;  // Int -> byte == fail
+    try {
+        proxyMyInterface.byteFoo();
+        throw new AssertionError("Expected ClassCastException");
+    } catch (ClassCastException e) {
+    }
+    check(fooInvocations == 21);
+
+    check(barInvocations == 20);
+    try {
+        proxyMyInterface.byteBar();
+        throw new AssertionError("Expected NPE");
+    } catch (ClassCastException e) {
+    }
+    check(barInvocations == 21);
+
+    check(fooInvocations == 21);
+    myHandler.returnType = Short.class;  // Short -> byte == fail
+    try {
+        proxyMyInterface.byteFoo();
+        throw new AssertionError("Expected ClassCastException");
+    } catch (ClassCastException e) {
+    }
+    check(fooInvocations == 22);
+
+    check(barInvocations == 21);
+    try {
+        proxyMyInterface.byteBar();
+        throw new AssertionError("Expected NPE");
+    } catch (ClassCastException e) {
+    }
+    check(barInvocations == 22);
+
+    check(fooInvocations == 22);
+    myHandler.returnType = Character.class;  // Char -> byte == fail
+    try {
+        proxyMyInterface.byteFoo();
+        throw new AssertionError("Expected ClassCastException");
+    } catch (ClassCastException e) {
+    }
+    check(fooInvocations == 23);
+
+    check(barInvocations == 22);
+    try {
+        proxyMyInterface.byteBar();
+        throw new AssertionError("Expected NPE");
+    } catch (ClassCastException e) {
+    }
+    check(barInvocations == 23);
+
+    check(fooInvocations == 23);
+    myHandler.returnType = Character.class;  // Char -> short == fail
+    try {
+        proxyMyInterface.shortFoo();
+        throw new AssertionError("Expected ClassCastException");
+    } catch (ClassCastException e) {
+    }
+    check(fooInvocations == 24);
+
+    check(barInvocations == 23);
+    try {
+        proxyMyInterface.shortBar();
+        throw new AssertionError("Expected NPE");
+    } catch (ClassCastException e) {
+    }
+    check(barInvocations == 24);
+
     System.out.println(testName + ".testProxyReturns PASSED");
   }
 
diff --git a/test/100-reflect2/expected.txt b/test/100-reflect2/expected.txt
index 9417174..0c567d4 100644
--- a/test/100-reflect2/expected.txt
+++ b/test/100-reflect2/expected.txt
@@ -22,7 +22,7 @@
 30
 62
 14
-java.lang.IllegalArgumentException: invalid primitive conversion from int to short
+java.lang.IllegalArgumentException: Invalid primitive conversion from int to short
 	at java.lang.reflect.Field.set(Native Method)
 	at Main.testFieldReflection(Main.java:121)
 	at Main.main(Main.java:269)
diff --git a/test/201-built-in-exception-detail-messages/src/Main.java b/test/201-built-in-exception-detail-messages/src/Main.java
index 9b67db6..f8da644 100644
--- a/test/201-built-in-exception-detail-messages/src/Main.java
+++ b/test/201-built-in-exception-detail-messages/src/Main.java
@@ -393,7 +393,7 @@
       m.invoke("hello"); // Wrong number of arguments.
       fail();
     } catch (IllegalArgumentException iae) {
-      assertEquals("wrong number of arguments; expected 1, got 0", iae.getMessage());
+      assertEquals("Wrong number of arguments; expected 1, got 0", iae.getMessage());
     }
     try {
       Method m = String.class.getMethod("charAt", int.class);
@@ -414,14 +414,14 @@
       m.invoke(new Integer(5)); // Wrong type for 'this'.
       fail();
     } catch (IllegalArgumentException iae) {
-      assertEquals("expected receiver of type java.lang.String, but got java.lang.Integer", iae.getMessage());
+      assertEquals("Expected receiver of type java.lang.String, but got java.lang.Integer", iae.getMessage());
     }
     try {
       Method m = String.class.getMethod("charAt", int.class);
       m.invoke(null); // Null for 'this'.
       fail();
     } catch (NullPointerException npe) {
-      assertEquals("expected receiver of type java.lang.String, but got null", npe.getMessage());
+      assertEquals("null receiver", npe.getMessage());
     }
   }
 
diff --git a/test/StackWalk/stack_walk_jni.cc b/test/StackWalk/stack_walk_jni.cc
index 92cfa99..4b472da 100644
--- a/test/StackWalk/stack_walk_jni.cc
+++ b/test/StackWalk/stack_walk_jni.cc
@@ -21,6 +21,7 @@
 #include "gc_map.h"
 #include "mirror/abstract_method.h"
 #include "mirror/abstract_method-inl.h"
+#include "mirror/class-inl.h"
 #include "mirror/object_array-inl.h"
 #include "mirror/object-inl.h"
 #include "object_utils.h"