Convert EqualityCompare to StrictCompare if reciever is either null or guaranteed to have default e…

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/dart_entry.h"
 #include "vm/flow_graph_allocator.h"
 #include "vm/flow_graph_builder.h"
@@ skipping 1298 matching lines @@
 
 Instruction* CheckClassInstr::Canonicalize(FlowGraphOptimizer* optimizer) {
   // TODO(vegorov): Replace class checks with null checks when ToNullableCid
   // matches.
 
   const intptr_t value_cid = value()->Type()->ToCid();
   if (value_cid == kDynamicCid) {
     return this;
   }
 
-  const intptr_t num_checks = unary_checks().NumberOfChecks();
-
-  for (intptr_t i = 0; i < num_checks; i++) {
-    if (value_cid == unary_checks().GetReceiverClassIdAt(i)) {
-      // No checks needed.
-      return NULL;
-    }
-  }
-
-  return this;
+  return unary_checks().HasReceiverClassId(value_cid) ? NULL : this;
 }
 
 
 Instruction* GuardFieldInstr::Canonicalize(FlowGraphOptimizer* optimizer) {
   if (field().guarded_cid() == kDynamicCid) {
     return NULL;  // Nothing to guard.
   }
 
   if (field().is_nullable() && value()->Type()->IsNull()) {
     return NULL;
@@ skipping 1049 matching lines @@
     default:
       UNREACHABLE();
   }
   return kPowRuntimeEntry;
 }
 
 
 #undef __
 
 }  // namespace dart