Attempt to do direct class comparison for type checks using CHA.

runtime/vm/flow_graph_compiler_x64.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/globals.h"  // Needed here to get TARGET_ARCH_X64.
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/flow_graph_compiler.h"
 
 #include "lib/error.h"
@@ skipping 374 matching lines @@
 RawSubtypeTestCache* FlowGraphCompiler::GenerateInlineInstanceof(
     intptr_t token_pos,
     const AbstractType& type,
     Label* is_instance_lbl,
     Label* is_not_instance_lbl) {
   if (type.IsVoidType()) {
     // A non-null value is returned from a void function, which will result in a
     // type error. A null value is handled prior to executing this inline code.
     return SubtypeTestCache::null();
   }
+  if (TypeCheckAsClassEquality(type)) {
+    const intptr_t type_cid = Class::Handle(type.type_class()).id();
+    const Register kInstanceReg = RAX;
+    __ testq(kInstanceReg, Immediate(kSmiTagMask));
+    if (type_cid == kSmiCid) {
+      __ j(ZERO, is_instance_lbl);
+    } else {
+      __ j(ZERO, is_not_instance_lbl);
+      __ CompareClassId(kInstanceReg, type_cid);
+      __ j(EQUAL, is_instance_lbl);
+    }
+    __ jmp(is_not_instance_lbl);
+    return SubtypeTestCache::null();
+  }
   if (type.IsInstantiated()) {
     const Class& type_class = Class::ZoneHandle(type.type_class());
     // A Smi object cannot be the instance of a parameterized class.
     // A class equality check is only applicable with a dst type of a
     // non-parameterized class or with a raw dst type of a parameterized class.
     if (type_class.HasTypeArguments()) {
       return GenerateInstantiatedTypeWithArgumentsTest(token_pos,
                                                        type,
                                                        is_instance_lbl,
                                                        is_not_instance_lbl);
@@ skipping 990 matching lines @@
 void ParallelMoveResolver::Exchange(const Address& mem1, const Address& mem2) {
   __ Exchange(mem1, mem2);
 }
 
 
 #undef __
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_X64