Separate the checks from StoreInstanceField so that they can be eliminated.

runtime/vm/flow_graph_optimizer.cc

 // Copyright (c) 2012, 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/cha.h"
 #include "vm/flow_graph_builder.h"
 #include "vm/hash_map.h"
 #include "vm/il_printer.h"
@@ skipping 349 matching lines @@
     if (!HasOneTarget(ic_data)) {
       // TODO(srdjan): Implement for mutiple targets.
       return false;
     }
     // Inline implicit instance getter.
     const String& field_name =
         String::Handle(Field::NameFromGetter(comp->function_name()));
     const Field& field = Field::Handle(GetField(class_ids[0], field_name));
     ASSERT(!field.IsNull());
 
-    LoadInstanceFieldComp* load;
-    // TODO(fschneider): Avoid generating redundant checks by checking the
-    // result-cid of the value.
+    // Type propagation has not run yet, we cannot eliminate the check.
     CheckClassComp* check =
         new CheckClassComp(comp->ArgumentAt(0)->value(), comp);
     const ICData& unary_checks =
         ICData::ZoneHandle(comp->ic_data()->AsUnaryClassChecks());
     check->set_ic_data(&unary_checks);
     BindInstr* check_instr = new BindInstr(BindInstr::kUnused, check);
     ASSERT(instr->env() != NULL);  // Always the case with SSA.
     // Attach the original environment to the check instruction.
     check_instr->set_env(instr->env());
     instr->set_env(NULL);
     check_instr->InsertBefore(instr);
-    load = new LoadInstanceFieldComp(field,
-                                     comp->ArgumentAt(0)->value(),
-                                     NULL,
-                                     false);  // Can not deoptimize.
+    LoadInstanceFieldComp* load =
+        new LoadInstanceFieldComp(field,
+                                  comp->ArgumentAt(0)->value(),
+                                  NULL);  // Can not deoptimize.
     instr->set_computation(load);
     RemovePushArguments(comp);
     return true;
   }
 
   // Not an implicit getter.
   MethodRecognizer::Kind recognized_kind =
       MethodRecognizer::RecognizeKind(target);
 
   // VM objects length getter.
@@ skipping 154 matching lines @@
   if (target.kind() != RawFunction::kImplicitSetter) {
     // Not an implicit setter.
     // TODO(srdjan): Inline special setters.
     return false;
   }
   // Inline implicit instance setter.
   const String& field_name =
       String::Handle(Field::NameFromSetter(comp->function_name()));
   const Field& field = Field::Handle(GetField(class_id, field_name));
   ASSERT(!field.IsNull());
+
+  // Type propagation has not run yet, we cannot eliminate the check.
+  CheckClassComp* check =
+      new CheckClassComp(comp->ArgumentAt(0)->value(), comp);
+  const ICData& unary_checks =
+      ICData::ZoneHandle(comp->ic_data()->AsUnaryClassChecks());
+  check->set_ic_data(&unary_checks);
+  BindInstr* check_instr = new BindInstr(BindInstr::kUnused, check);
+  ASSERT(instr->env() != NULL);  // Always the case with SSA.
+  // Attach the original environment to the check instruction.
+  check_instr->set_env(instr->env());
+  instr->set_env(NULL);
+  check_instr->InsertBefore(instr);
   StoreInstanceFieldComp* store = new StoreInstanceFieldComp(
       field,
       comp->ArgumentAt(0)->value(),
       comp->ArgumentAt(1)->value(),
-      comp);
-  store->set_ic_data(comp->ic_data());
+      NULL);  // Can not deoptimize.
   instr->set_computation(store);
   RemovePushArguments(comp);
   return true;
 }
 
 
 void FlowGraphOptimizer::VisitRelationalOp(RelationalOpComp* comp,
                                            BindInstr* instr) {
   if (!comp->HasICData()) return;
 
@@ skipping 361 matching lines @@
         OS::Print("Replacing v%d with v%d\n",
                   instr->ssa_temp_index(),
                   result->ssa_temp_index());
       }
     }
   }
 }
 
 
 }  // namespace dart