When attempting to to inline a field getter we use the incoming cid. That type may differ between v…

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/flow_graph_builder.h"
 #include "vm/flow_graph_compiler.h"
@@ skipping 69 matching lines @@
   ASSERT(call->HasICData());
   if (call->ic_data()->NumberOfChecks() > 0) {
     // This occurs when an instance call has too many checks.
     // TODO(srdjan): Replace IC call with megamorphic call.
     return false;
   }
   GrowableArray<intptr_t> class_ids(call->ic_data()->num_args_tested());
   ASSERT(call->ic_data()->num_args_tested() <= call->ArgumentCount());
   for (intptr_t i = 0; i < call->ic_data()->num_args_tested(); i++) {
     intptr_t cid = call->PushArgumentAt(i)->value()->Type()->ToCid();
+    if (cid == kDynamicCid) {

[Vyacheslav Egorov (Google), 2013/03/26 18:56:13]

How about a bit different approach:

In Definition::ReplaceUsesWith(Definition* other) when iterating over input uses
we can check if current->Type() == this->Type() and if this is the case reset
current->type_ to NULL.

To avoid doing unnecessary updates we can have bool argument to
ReplaceUsesWith/ReplaceWith that controls whether or not we update types.

And in the FlowGraphOptimizer we can have a member that says update_types_ that
is true when we are in the ApplyClassIds.

In this case we will keep types more up to date, and will need to have any
special casing here.

[srdjan, 2013/03/26 20:34:52]

Yes, update the type in ReplaceUsesWith. In order to implement simple code, I
decided to always set reaching type to NULL. Did not measure negative impact on
compilation speed of dart2js.

+      // Definition's type may differ from value's type as it may have been
+      // changed by guarded_cid of an inlined LoadField.
+      cid = call->PushArgumentAt(i)->value()->definition()->Type()->ToCid();
+    }
     class_ids.Add(cid);
   }
-  // TODO(srdjan): Test for other class_ids > 1.
-  if (class_ids.length() != 1) return false;
+  // TODO(srdjan): Test for number of arguments checked greater than 1.
+  if (class_ids.length() != 1) {
+    return false;
+  }
   if (class_ids[0] != kDynamicCid) {
     const intptr_t num_named_arguments = call->argument_names().IsNull() ?
         0 : call->argument_names().Length();
     const Class& receiver_class = Class::Handle(
         Isolate::Current()->class_table()->At(class_ids[0]));
     Function& function = Function::Handle();
     function = Resolver::ResolveDynamicForReceiverClass(
         receiver_class,
         call->function_name(),
         call->ArgumentCount(),
@@ skipping 4523 matching lines @@
   if (changed) {
     // We may have changed the block order and the dominator tree.
     flow_graph->DiscoverBlocks();
     GrowableArray<BitVector*> dominance_frontier;
     flow_graph->ComputeDominators(&dominance_frontier);
   }
 }
 
 
 }  // namespace dart