Do not eagerly finalize when optimizing. Remove allocation of temporary strings in new space.

runtime/vm/flow_graph_optimizer.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/flow_graph_optimizer.h"
 
 #include "vm/bit_vector.h"
 #include "vm/cha.h"
 #include "vm/compiler.h"
 #include "vm/cpu.h"
@@ skipping 206 matching lines @@
     }
   }
 
   if (all_cids_known) {
     const Array& args_desc_array = Array::Handle(Z,
         ArgumentsDescriptor::New(call->ArgumentCount(),
                                  call->argument_names()));
     ArgumentsDescriptor args_desc(args_desc_array);
     const Class& receiver_class = Class::Handle(Z,
         isolate()->class_table()->At(class_ids[0]));
+    if (!receiver_class.is_finalized()) {
+      // Do not eagerly finalize classes.

[regis, 2015/09/25 20:55:24]

I do not see how we were finalizing before.

[srdjan, 2015/09/25 21:15:59]

Added to comment:

Callee's receiver class may not be finalized yet. ResolveDynamicForReceiverClass
can cause class finalization, since callee's receiver class may not be finalized
yet.

+      return false;
+    }
     const Function& function = Function::Handle(Z,
         Resolver::ResolveDynamicForReceiverClass(
             receiver_class,
             call->function_name(),
             args_desc));
     if (function.IsNull()) {
       return false;
     }
 
     // Create new ICData, do not modify the one attached to the instruction
@@ skipping 8545 matching lines @@
 
   // Insert materializations at environment uses.
   for (intptr_t i = 0; i < exits_collector_.exits().length(); i++) {
     CreateMaterializationAt(
         exits_collector_.exits()[i], alloc, *slots);
   }
 }
 
 
 }  // namespace dart