Add fast Smi op version of switchable instance calls.

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/code_patcher.h"
 #include "vm/compiler.h"
@@ skipping 1031 matching lines @@
     target_function = InlineCacheMissHelper(receiver, descriptor, name);
   }
   if (target_function.IsNull()) {
     ASSERT(!FLAG_lazy_dispatchers);
     arguments.SetReturn(target_function);
     return;
   }
 
   if (ic_data_or_cache.IsICData()) {
     const ICData& ic_data = ICData::Cast(ic_data_or_cache);
-    ic_data.AddReceiverCheck(receiver.GetClassId(), target_function);
+
+    if (ic_data.NumArgsTested() == 1) {
+      ic_data.AddReceiverCheck(receiver.GetClassId(), target_function);
+    } else {
+      ASSERT(ic_data.NumArgsTested() == 2);
+      GrowableArray<intptr_t> class_ids(2);
+      class_ids.Add(receiver.GetClassId());
+      class_ids.Add(kDynamicCid);  // No one will read this.
+      ic_data.AddCheck(class_ids, target_function);
+    }
+
     if (ic_data.NumberOfChecks() > FLAG_max_polymorphic_checks) {
       // Switch to megamorphic call.
       const MegamorphicCache& cache = MegamorphicCache::Handle(zone,
           MegamorphicCacheTable::Lookup(isolate, name, descriptor));
       DartFrameIterator iterator;
       StackFrame* miss_function_frame = iterator.NextFrame();
       ASSERT(miss_function_frame->IsDartFrame());
       StackFrame* caller_frame = iterator.NextFrame();
       ASSERT(caller_frame->IsDartFrame());
       const Code& code = Code::Handle(zone, caller_frame->LookupDartCode());
@@ skipping 818 matching lines @@
   const intptr_t elm_size = old_data.ElementSizeInBytes();
   const TypedData& new_data =
       TypedData::Handle(TypedData::New(cid, new_size, Heap::kOld));
   TypedData::Copy(new_data, 0, old_data, 0, old_size * elm_size);
   typed_data_cell.SetAt(0, new_data);
   arguments.SetReturn(new_data);
 }
 
 
 }  // namespace dart