VM: Better type propagation for string objects.

runtime/vm/intermediate_language.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/intermediate_language.h"
 
 #include "vm/bit_vector.h"
 #include "vm/constant_propagator.h"
 #include "vm/cpu.h"
 #include "vm/dart_entry.h"
@@ skipping 2255 matching lines @@
          (cid == kMintCid) ||
          (cid == kBigintCid) ||
          (cid == kDoubleCid);
 }
 
 
 static bool MaybeNumber(CompileType* type) {
   ASSERT(Type::Handle(Type::Number()).IsMoreSpecificThan(
          Type::Handle(Type::Number()), NULL));
   return type->ToAbstractType()->IsDynamicType()
+      || type->ToAbstractType()->IsObjectType()
       || type->ToAbstractType()->IsTypeParameter()
       || type->IsMoreSpecificThan(Type::Handle(Type::Number()));
 }
 
 
 // Returns a replacement for a strict comparison and signals if the result has
 // to be negated.
 static Definition* CanonicalizeStrictCompare(StrictCompareInstr* compare,
                                              bool* negated) {
   // Use propagated cid and type information to eliminate number checks.
@@ skipping 1300 matching lines @@
     case Token::kTRUNCDIV: return 0;
     case Token::kMOD: return 1;
     default: UNIMPLEMENTED(); return -1;
   }
 }
 
 
 #undef __
 
 }  // namespace dart