Do not recompute unary_checks repeatedly. Add special (and quicker) way to check for method overrid…

runtime/vm/cha.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/cha.h"
 #include "vm/class_table.h"
 #include "vm/flags.h"
 #include "vm/freelist.h"
 #include "vm/object.h"
 #include "vm/raw_object.h"
@@ skipping 52 matching lines @@
   ASSERT(cid > kInstanceCid);
   const ClassTable& class_table = *Isolate::Current()->class_table();
   const Class& cls = Class::Handle(class_table.At(cid));
   ASSERT(!cls.IsNull());
   ZoneGrowableArray<intptr_t>* ids = new ZoneGrowableArray<intptr_t>();
   CollectSubclassIds(ids, cls);
   return ids;
 }
 
 
+bool CHA::HasOverride(const Class& cls, const String& function_name) {
+  const GrowableObjectArray& cls_direct_subclasses =
+      GrowableObjectArray::Handle(cls.direct_subclasses());
+  if (cls_direct_subclasses.IsNull()) {
+    return false;
+  }
+  Class& direct_subclass = Class::Handle();
+  for (intptr_t i = 0; i < cls_direct_subclasses.Length(); i++) {
+    direct_subclass ^= cls_direct_subclasses.At(i);
+    if (direct_subclass.LookupDynamicFunction(function_name) !=
+        Function::null()) {
+      return true;
+    }
+    if (HasOverride(direct_subclass, function_name)) {
+      return true;
+    }
+  }
+  return false;
+}
+
+
 ZoneGrowableArray<Function*>* CHA::GetNamedInstanceFunctionsOf(
     const ZoneGrowableArray<intptr_t>& cids,
     const String& function_name) {
   ASSERT(!function_name.IsNull());
   const ClassTable& class_table = *Isolate::Current()->class_table();
   ZoneGrowableArray<Function*>* functions = new ZoneGrowableArray<Function*>();
   Class& cls = Class::Handle();
   Function& cls_function = Function::Handle();
   for (intptr_t i = 0; i < cids.length(); i++) {
     const intptr_t cid = cids[i];
@@ skipping 12 matching lines @@
   ASSERT(!function.IsNull());
   ASSERT(function.IsDynamicFunction());
   const Class& function_owner = Class::Handle(function.Owner());
   const String& function_name = String::Handle(function.name());
   ZoneGrowableArray<intptr_t>* cids = new ZoneGrowableArray<intptr_t>();
   CollectSubclassIds(cids, function_owner);
   return GetNamedInstanceFunctionsOf(*cids, function_name);
 }
 
 }  // namespace dart