Reland "Recognize and optimize a.runtimeType == b.runtimeType pattern."

runtime/vm/simulator_dbc.cc

 // Copyright (c) 2016, 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 <setjmp.h>  // NOLINT
 #include <stdlib.h>
 
 #include "vm/globals.h"
 #if defined(TARGET_ARCH_DBC)
 
@@ skipping 261 matching lines @@
   }
 
   static bool ObjectRuntimeType(Thread* thread,
                                 RawObject** FP,
                                 RawObject** result) {
     RawObject** args = FrameArguments(FP, 1);
     const intptr_t cid = GetClassId(args[0]);
     if (cid == kClosureCid) {
       return false;
     }
+    if (cid < kNumPredefinedCids) {
+      if (cid == kDoubleCid) {
+        *result = thread->isolate()->object_store()->double_type();
+        return true;
+      } else if (RawObject::IsStringClassId(cid)) {
+        *result = thread->isolate()->object_store()->string_type();
+        return true;
+      } else if (RawObject::IsIntegerClassId(cid)) {
+        *result = thread->isolate()->object_store()->int_type();
+        return true;
+      }
+    }
     RawClass* cls = thread->isolate()->class_table()->At(cid);
     if (cls->ptr()->num_type_arguments_ != 0) {
       return false;
     }
     RawType* typ = cls->ptr()->canonical_type_;
     if (typ == Object::null()) {
       return false;
     }
     *result = static_cast<RawObject*>(typ);
     return true;
@@ skipping 3446 matching lines @@
   pc_ = pc;
   special_[kExceptionSpecialIndex] = raw_exception;
   special_[kStacktraceSpecialIndex] = raw_stacktrace;
   buf->Longjmp();
   UNREACHABLE();
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_DBC