Set statically known ResultCid for AllocateObject.

runtime/vm/intermediate_language.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/intermediate_language.h"
 
 #include "vm/bit_vector.h"
 #include "vm/dart_entry.h"
 #include "vm/flow_graph_allocator.h"
 #include "vm/flow_graph_builder.h"
@@ skipping 1730 matching lines @@
       (left()->ResultCid() == kBoolCid)) {
     // Return left subexpression as the replacement for this instruction.
     return left_defn;
   }
   return this;
 }
 
 
 Instruction* CheckClassInstr::Canonicalize(FlowGraphOptimizer* optimizer) {
   const intptr_t value_cid = value()->ResultCid();
+  if (value_cid == kDynamicCid) {
+    return this;
+  }
+
   const intptr_t num_checks = unary_checks().NumberOfChecks();
-  if ((num_checks == 1) &&
-      (value_cid == unary_checks().GetReceiverClassIdAt(0))) {
-    // No checks needed.
-    return NULL;
+
+  for (intptr_t i = 0; i < num_checks; i++) {
+    if (value_cid == unary_checks().GetReceiverClassIdAt(i)) {
+      // No checks needed.
+      return NULL;
+    }
   }
+
   return this;
 }
 
 
 Instruction* CheckSmiInstr::Canonicalize(FlowGraphOptimizer* optimizer) {
   return (value()->ResultCid() == kSmiCid) ?  NULL : this;
 }
 
 
 Instruction* CheckEitherNonSmiInstr::Canonicalize(
@@ skipping 1194 matching lines @@
     default:
       UNREACHABLE();
       return -1;
   }
 }
 
 
 #undef __
 
 }  // namespace dart