Change == into an instance call to allow polymorphic inlining of ==.

runtime/vm/flow_graph_inliner.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_inliner.h"
 
 #include "vm/block_scheduler.h"
 #include "vm/compiler.h"
 #include "vm/flags.h"
 #include "vm/flow_graph.h"
@@ skipping 153 matching lines @@
     instruction_count_ = 0;
     for (BlockIterator block_it = graph.postorder_iterator();
          !block_it.Done();
          block_it.Advance()) {
       for (ForwardInstructionIterator it(block_it.Current());
            !it.Done();
            it.Advance()) {
         ++instruction_count_;
         Instruction* current = it.Current();
         if (current->IsStaticCall() ||
-            current->IsClosureCall() ||
-            (current->IsPolymorphicInstanceCall() &&
-             !current->AsPolymorphicInstanceCall()->HasRecognizedTarget())) {
+            current->IsClosureCall()) {
           ++call_site_count_;
+          continue;
+        }
+        if (current->IsPolymorphicInstanceCall()) {
+          PolymorphicInstanceCallInstr* call =
+              current->AsPolymorphicInstanceCall();
+          // These checks make sure that the number of call-sites counted does
+          // not change relative to the time when the current set of inlining
+          // parameters was fixed.
+          // TODO(fschneider): Determine new heuristic parameters that avoid
+          // these checks entirely.
+          if (!call->HasRecognizedTarget() &&

[Florian Schneider, 2013/10/28 13:34:19]

This is needed to avoid performance regressions with our current inlining
heuristics. Long term we should find new parameters that work without these two
checks.

+              (call->instance_call()->token_kind() != Token::kEQ)) {
+            ++call_site_count_;
+          }
         }
       }
     }
   }
 
   intptr_t call_site_count() const { return call_site_count_; }
   intptr_t instruction_count() const { return instruction_count_; }
 
  private:
   intptr_t call_site_count_;
@@ skipping 1308 matching lines @@
         OS::Print("After Inlining of %s\n", flow_graph_->
                   parsed_function().function().ToFullyQualifiedCString());
         FlowGraphPrinter printer(*flow_graph_);
         printer.PrintBlocks();
       }
     }
   }
 }
 
 }  // namespace dart