Improve type test and type equality for generics (issue 15148).

runtime/vm/flow_graph_compiler.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/globals.h"  // Needed here to get TARGET_ARCH_XXX.
 
 #include "vm/flow_graph_compiler.h"
 
 #include "vm/cha.h"
 #include "vm/dart_entry.h"
@@ skipping 1170 matching lines @@
   // Requires CHA, which can be applied in optimized code only,
   if (!FLAG_use_cha || !is_optimizing()) return false;
   if (!type.IsInstantiated()) return false;
   const Class& type_class = Class::Handle(type.type_class());
   // Signature classes have different type checking rules.
   if (type_class.IsSignatureClass()) return false;
   // Could be an interface check?
   if (type_class.is_implemented()) return false;
   const intptr_t type_cid = type_class.id();
   if (CHA::HasSubclasses(type_cid)) return false;
-  if (type_class.NumTypeArguments() > 0) {
+  const intptr_t num_type_args = type_class.NumTypeArguments();
+  if (num_type_args > 0) {
     // Only raw types can be directly compared, thus disregarding type
     // arguments.
+    const intptr_t num_type_params = type_class.NumTypeParameters();
+    const intptr_t from_index = num_type_args - num_type_params;
     const AbstractTypeArguments& type_arguments =
         AbstractTypeArguments::Handle(type.arguments());
     const bool is_raw_type = type_arguments.IsNull() ||
-        type_arguments.IsRaw(type_arguments.Length());
+        type_arguments.IsRaw(from_index, num_type_params);
     return is_raw_type;
   }
   return true;
 }
 
 
 static int HighestCountFirst(const CidTarget* a, const CidTarget* b) {
   // Negative if 'a' should sort before 'b'.
   return b->count - a->count;
 }
 
 
 // Returns 'sorted' array in decreasing count order.
 // The expected number of elements to sort is less than 10.
 void FlowGraphCompiler::SortICDataByCount(const ICData& ic_data,
                                           GrowableArray<CidTarget>* sorted) {
   ASSERT(ic_data.num_args_tested() == 1);
   const intptr_t len = ic_data.NumberOfChecks();
   sorted->Clear();
 
   for (int i = 0; i < len; i++) {
     sorted->Add(CidTarget(ic_data.GetReceiverClassIdAt(i),
                           &Function::ZoneHandle(ic_data.GetTargetAt(i)),
                           ic_data.GetCountAt(i)));
   }
   sorted->Sort(HighestCountFirst);
 }
 
 }  // namespace dart