VM: Fix bug in polymorphic inlining of recognized methods.

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 1146 matching lines @@
   first->LinkTo(second);
   return second;
 }
 
 
 bool PolymorphicInliner::TryInlineRecognizedMethod(intptr_t receiver_cid,
                                                    const Function& target) {
   FlowGraphOptimizer optimizer(owner_->caller_graph());
   TargetEntryInstr* entry;
   Definition* last;
+  // Replace the receiver argument with a redefinition to prevent code from
+  // the inlined body from being hoisted above the inlined entry.
+  GrowableArray<Definition*> arguments(call_->ArgumentCount());
+  Definition* receiver = call_->ArgumentAt(0);
+    RedefinitionInstr* redefinition =
+        new RedefinitionInstr(new Value(receiver));
+    redefinition->set_ssa_temp_index(
+        owner_->caller_graph()->alloc_ssa_temp_index());
   if (optimizer.TryInlineRecognizedMethod(receiver_cid,
                                           target,
                                           call_,
+                                          redefinition,
                                           call_->instance_call()->token_pos(),
                                           *call_->instance_call()->ic_data(),
                                           &entry, &last)) {
     // Create a graph fragment.
+    redefinition->InsertAfter(entry);
     InlineExitCollector* exit_collector =
         new InlineExitCollector(owner_->caller_graph(), call_);
 
     ReturnInstr* result =
         new ReturnInstr(call_->instance_call()->token_pos(),
                         new Value(last));
     owner_->caller_graph()->AppendTo(
         last,
         result,
         call_->env(),  // Return can become deoptimization target.
@@ skipping 312 matching lines @@
         OS::Print("After Inlining of %s\n", flow_graph_->
                   parsed_function().function().ToFullyQualifiedCString());
         FlowGraphPrinter printer(*flow_graph_);
         printer.PrintBlocks();
       }
     }
   }
 }
 
 }  // namespace dart