Improve type propagation for AssertAssignable.

runtime/vm/flow_graph_builder.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_builder.h"
 
 #include "lib/invocation_mirror.h"
 #include "vm/ast_printer.h"
 #include "vm/bit_vector.h"
 #include "vm/class_finalizer.h"
@@ skipping 3766 matching lines @@
       pos = 1;
     }
     while (pos < num_params) {
       const LocalVariable& parameter = *scope->VariableAt(pos);
       ASSERT(parameter.owner() == scope);
       if (!CanSkipTypeCheck(parameter.token_pos(),
                             NULL,
                             parameter.type(),
                             parameter.name())) {
         Value* parameter_value = Bind(BuildLoadLocal(parameter));
-        AssertAssignableInstr* assert_assignable =
-            BuildAssertAssignable(parameter.token_pos(),
-                                  parameter_value,
-                                  parameter.type(),
-                                  parameter.name());
-        parameter_value = Bind(assert_assignable);
-        // Store the type checked argument back to its corresponding local
-        // variable so that ssa renaming detects the dependency and makes use
-        // of the checked type in type propagation.
-        Do(BuildStoreLocal(parameter, parameter_value));
+        Do(BuildAssertAssignable(parameter.token_pos(),
+                                 parameter_value,
+                                 parameter.type(),
+                                 parameter.name()));
       }
       pos++;
     }
   }
 
   // Continuation part:
   // If this node sequence is the body of an async closure leave room for a
   // preamble. The preamble is generated after visiting the body.
   GotoInstr* preamble_start = NULL;
   if (is_top_level_sequence &&
@@ skipping 448 matching lines @@
   Report::MessageF(Report::kBailout,
                    Script::Handle(function.script()),
                    function.token_pos(),
                    "FlowGraphBuilder Bailout: %s %s",
                    String::Handle(function.name()).ToCString(),
                    reason);
   UNREACHABLE();
 }
 
 }  // namespace dart