Optimizing noSuchMethod invocation with no arguments.

runtime/vm/code_generator.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/code_generator.h"
 
 #include "vm/assembler.h"
 #include "vm/ast.h"
 #include "vm/bigint_operations.h"
 #include "vm/code_patcher.h"
@@ skipping 863 matching lines @@
     const Array& args_descriptor_array) {
   const Instance& receiver = *args[0];
   const Code& target_code =
       Code::Handle(ResolveCompileInstanceCallTarget(receiver,
                                                     ic_data,
                                                     args_descriptor_array));
   if (target_code.IsNull()) {
     // Let the megamorphic stub handle special cases: NoSuchMethod,
     // closure calls.
     if (FLAG_trace_ic) {
-      OS::PrintErr("InlineCacheMissHandler NULL code for receiver: %s\n",
-          receiver.ToCString());
+      OS::PrintErr("InlineCacheMissHandler NULL code for %s receiver: %s\n",
+                   String::Handle(ic_data.target_name()).ToCString(),
+                   receiver.ToCString());
     }
     return Function::null();
   }
   const Function& target_function =
       Function::Handle(target_code.function());
   ASSERT(!target_function.IsNull());
   if (args.length() == 1) {
     ic_data.AddReceiverCheck(args[0]->GetClassId(), target_function);
   } else {
     GrowableArray<intptr_t> class_ids(args.length());
@@ skipping 254 matching lines @@
                                      Object* result) {
   // 1. Check if there is a getter with the same name.
   const String& getter_name = String::Handle(Field::GetterName(target_name));
   const int kNumArguments = 1;
   const int kNumNamedArguments = 0;
   const Function& getter = Function::Handle(
       Resolver::ResolveDynamicForReceiverClass(receiver_class,
                                                getter_name,
                                                kNumArguments,
                                                kNumNamedArguments));
-  if (getter.IsNull() || getter.IsMethodExtractor()) {
+  if (getter.IsNull() ||
+      getter.IsMethodExtractor() ||
+      getter.IsNoSuchMethodDispatcher()) {
     return false;
   }
 
   // 2. Invoke the getter.
   const Array& args = Array::Handle(Array::New(kNumArguments));
   args.SetAt(0, receiver);
   const Object& value = Object::Handle(DartEntry::InvokeFunction(getter, args));
 
   // 3. If the getter threw an exception, treat it as no such method.
   if (value.IsUnhandledException()) return false;
 
   // 4. If there was some other error, propagate it.
   CheckResultError(value);
 
   // 5. Invoke the value as a closure.
   Instance& instance = Instance::Handle();
   instance ^= value.raw();
   arguments.SetAt(0, instance);
   *result = DartEntry::InvokeClosure(arguments, arguments_descriptor);
   CheckResultError(*result);
   return true;
 }
 
 
+// Create a method for noSuchMethod invocation and attach it to the receiver
+// class.
+static RawFunction* CreateNoSuchMethodDispatcher(
+    const String& target_name,
+    const Class& receiver_class,
+    const Array& arguments_descriptor) {
+  Function& invocation = Function::Handle(
+    Function::New(String::Handle(Symbols::New(target_name)),

[srdjan, 2013/06/19 18:10:56]

indent 4 spaces

[Florian Schneider, 2013/06/20 09:23:33]

Done.

+                  RawFunction::kNoSuchMethodDispatcher,
+                  false,  // Not static.
+                  false,  // Not const.
+                  false,  // Not abstract.
+                  false,  // Not external.
+                  receiver_class,
+                  0));  // No token position.
+
+  // Initialize signature: receiver is a single fixed parameter.
+  const intptr_t kNumParameters = 1;
+  invocation.set_num_fixed_parameters(kNumParameters);
+  invocation.SetNumOptionalParameters(0, 0);
+  invocation.set_parameter_types(Array::Handle(Array::New(kNumParameters,
+                                                         Heap::kOld)));
+  invocation.set_parameter_names(Array::Handle(Array::New(kNumParameters,
+                                                         Heap::kOld)));
+  invocation.SetParameterTypeAt(0, Type::Handle(Type::DynamicType()));
+  invocation.SetParameterNameAt(0, Symbols::This());
+  invocation.set_result_type(Type::Handle(Type::DynamicType()));
+
+  receiver_class.AddFunction(invocation);
+
+  return invocation.raw();
+}
+
+
 // The IC miss handler has failed to find a (cacheable) instance function to
 // invoke.  Handle three possibilities:
 //
 // 1. If the call was a getter o.f, there may be an instance function with
 //    the same name.  If so, create an implicit closure and return it.
 //
 // 2. If the call was an instance call o.f(...), there may be a getter with
 //    the same name.  If so, invoke it.  If the value is a closure, invoke
 //    it with the given arguments.  If the value is a non-closure, attempt
 //    to invoke "call" on it.
@@ skipping 14 matching lines @@
   }
   const String& target_name = String::Handle(ic_data.target_name());
 
   Object& result = Object::Handle();
   if (!ResolveCallThroughGetter(receiver,
                                 receiver_class,
                                 target_name,
                                 args_descriptor,
                                 args,
                                 &result)) {
+    ArgumentsDescriptor desc(args_descriptor);
+    if (desc.Count() == 1 && desc.PositionalCount() == 1) {

[srdjan, 2013/06/19 18:10:56]

Add parentheses.
Add TODO to handle other cases.

[Florian Schneider, 2013/06/20 09:23:33]

Done.

+      // Create Function for noSuchMethodInvocation and add it to the class.
+      Function& target_function = Function::Handle();
+      target_function ^= CreateNoSuchMethodDispatcher(target_name,
+                                                      receiver_class,
+                                                      args_descriptor);
+
+      // Update IC data.
+      ASSERT(!target_function.IsNull());
+      ic_data.AddReceiverCheck(receiver.GetClassId(), target_function);
+      if (FLAG_trace_ic) {
+        OS::PrintErr("NoSuchMethod IC miss: adding <%s> id:%"Pd" -> <%s>\n",
+            Class::Handle(receiver.clazz()).ToCString(),
+            receiver.GetClassId(),
+            target_function.ToCString());
+      }
+      result =
+          DartEntry::InvokeFunction(target_function, args, args_descriptor);

[srdjan, 2013/06/19 18:10:56]

Why not:
  result =DartEntry::InvokeFunction(targ..
} else {
   result = DartEntry::InvokeNoSuchMethod(receiver, ...
}
CheckResultError(result);
arguments.SetReturn(result);

[Florian Schneider, 2013/06/20 09:23:33]

Done.

+      CheckResultError(result);
+      arguments.SetReturn(result);
+      return;
+    }
     result = DartEntry::InvokeNoSuchMethod(receiver,
                                            target_name,
                                            args,
                                            args_descriptor);
   }
   CheckResultError(result);
   arguments.SetReturn(result);
 }
 
 
@@ skipping 577 matching lines @@
 //   Arg1: Value that is being stored.
 DEFINE_RUNTIME_ENTRY(UpdateFieldCid, 2) {
   ASSERT(arguments.ArgCount() == kUpdateFieldCidRuntimeEntry.argument_count());
   const Field& field = Field::CheckedHandle(arguments.ArgAt(0));
   const Object& value = Object::Handle(arguments.ArgAt(1));
 
   field.UpdateCid(value.GetClassId());
 }
 
 }  // namespace dart