Polymorphic calls in precompilation invoke megamorphic calls when tests fail (instead of deoptimizi…

runtime/vm/flow_graph_optimizer.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/flow_graph_optimizer.h"
 
 #include "vm/bit_vector.h"
 #include "vm/cha.h"
 #include "vm/compiler.h"
 #include "vm/cpu.h"
@@ skipping 10 matching lines @@
 #include "vm/precompiler.h"
 #include "vm/resolver.h"
 #include "vm/scopes.h"
 #include "vm/stack_frame.h"
 #include "vm/symbols.h"
 
 namespace dart {
 
 DEFINE_FLAG(int, getter_setter_ratio, 13,
     "Ratio of getter/setter usage used for double field unboxing heuristics");
-DEFINE_FLAG(bool, guess_other_cid, true,
+DEFINE_FLAG(bool, guess_icdata_cid, true,
     "Artificially create type feedback for arithmetic etc. operations"
     " by guessing the other unknown argument cid");
 DEFINE_FLAG(bool, load_cse, true, "Use redundant load elimination.");
 DEFINE_FLAG(bool, dead_store_elimination, true, "Eliminate dead stores");
 DEFINE_FLAG(int, max_polymorphic_checks, 4,
     "Maximum number of polymorphic check, otherwise it is megamorphic.");
 DEFINE_FLAG(int, max_equality_polymorphic_checks, 32,
     "Maximum number of polymorphic checks in equality operator,"
     " otherwise use megamorphic dispatch.");
 DEFINE_FLAG(bool, merge_sin_cos, false, "Merge sin/cos into sincos");
@@ skipping 147 matching lines @@
   for (intptr_t i = 0; i < call->ic_data()->NumArgsTested(); i++) {
     class_ids.Add(call->PushArgumentAt(i)->value()->Type()->ToCid());
   }
 
   const Token::Kind op_kind = call->token_kind();
   if (Token::IsRelationalOperator(op_kind) ||
       Token::IsEqualityOperator(op_kind) ||
       Token::IsBinaryOperator(op_kind)) {
     // Guess cid: if one of the inputs is a number assume that the other
     // is a number of same type.
-    if (FLAG_guess_other_cid) {
+    if (FLAG_guess_icdata_cid) {
       const intptr_t cid_0 = class_ids[0];
       const intptr_t cid_1 = class_ids[1];
       if ((cid_0 == kDynamicCid) && (IsNumberCid(cid_1))) {
         class_ids[0] = cid_1;
       } else if (IsNumberCid(cid_0) && (cid_1 == kDynamicCid)) {
         class_ids[1] = cid_0;
       }
     }
   }
 
@@ skipping 37 matching lines @@
     if (class_ids.length() > 1) {
       ic_data.AddCheck(class_ids, function);
     } else {
       ASSERT(class_ids.length() == 1);
       ic_data.AddReceiverCheck(class_ids[0], function);
     }
     call->set_ic_data(&ic_data);
     return true;
   }
 
+  if (Compiler::always_optimize() &&
+      (isolate()->object_store()->unique_dynamic_targets() != Array::null())) {
+    // Check if the target is unique.
+    Function& target_function = Function::Handle(Z);
+    Precompiler::GetUniqueDynamicTarget(
+        isolate(), call->function_name(), &target_function);
+    // Calls with named arguments must be resolved/checked at runtime.
+    String& error_message = String::Handle(Z);
+    if (!target_function.IsNull() &&
+        !target_function.HasOptionalNamedParameters() &&
+        target_function.AreValidArgumentCounts(call->ArgumentCount(), 0,
+                                               &error_message)) {
+      const intptr_t cid = Class::Handle(Z, target_function.Owner()).id();
+      const ICData& ic_data = ICData::ZoneHandle(Z,
+          ICData::NewFrom(*call->ic_data(), 1));
+      ic_data.AddReceiverCheck(cid, target_function);
+      call->set_ic_data(&ic_data);
+      return true;
+    }
+  }
+
   // Check if getter or setter in function's class and class is currently leaf.
-  if ((call->token_kind() == Token::kGET) ||
-      (call->token_kind() == Token::kSET)) {
+  if (FLAG_guess_icdata_cid &&
+      ((call->token_kind() == Token::kGET) ||
+          (call->token_kind() == Token::kSET))) {
     const Class& owner_class = Class::Handle(Z, function().Owner());
     if (!owner_class.is_abstract() &&
         !CHA::HasSubclasses(owner_class) &&
         !CHA::IsImplemented(owner_class)) {
       const Array& args_desc_array = Array::Handle(Z,
           ArgumentsDescriptor::New(call->ArgumentCount(),
                                    call->argument_names()));
       ArgumentsDescriptor args_desc(args_desc_array);
       const Function& function = Function::Handle(Z,
           Resolver::ResolveDynamicForReceiverClass(owner_class,
                                                    call->function_name(),
                                                    args_desc));
       if (!function.IsNull()) {
         const ICData& ic_data = ICData::ZoneHandle(Z,
             ICData::NewFrom(*call->ic_data(), class_ids.length()));
         ic_data.AddReceiverCheck(owner_class.id(), function);
         call->set_ic_data(&ic_data);
         return true;
       }
     }
   }
 
-  if (FLAG_precompilation &&
-      (isolate()->object_store()->unique_dynamic_targets() != Array::null())) {
-    // Check if the target is unique.
-    Function& target_function = Function::Handle(Z);
-    Precompiler::GetUniqueDynamicTarget(
-        isolate(), call->function_name(), &target_function);
-    // Calls with named arguments must be resolved/checked at runtime.
-    String& error_message = String::Handle(Z);
-    if (!target_function.IsNull() &&
-        !target_function.HasOptionalNamedParameters() &&
-        target_function.AreValidArgumentCounts(call->ArgumentCount(), 0,
-                                               &error_message)) {
-      const intptr_t cid = Class::Handle(Z, target_function.Owner()).id();
-      const ICData& ic_data = ICData::ZoneHandle(Z,
-          ICData::NewFrom(*call->ic_data(), 1));
-      ic_data.AddReceiverCheck(cid, target_function);
-      call->set_ic_data(&ic_data);
-      return true;
-    }
-  }
-
   return false;
 }
 
 
 const ICData& FlowGraphOptimizer::TrySpecializeICData(const ICData& ic_data,
                                                       intptr_t cid) {
   ASSERT(ic_data.NumArgsTested() == 1);
 
   if ((ic_data.NumberOfUsedChecks() == 1) && ic_data.HasReceiverClassId(cid)) {
     return ic_data;  // Nothing to do
@@ skipping 8540 matching lines @@
 
   // Insert materializations at environment uses.
   for (intptr_t i = 0; i < exits_collector_.exits().length(); i++) {
     CreateMaterializationAt(
         exits_collector_.exits()[i], alloc, *slots);
   }
 }
 
 
 }  // namespace dart