Record call counts also for megamorphic calls.

src/type-feedback-vector.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/type-feedback-vector.h"
 
 #include "src/code-stubs.h"
 #include "src/ic/ic.h"
 #include "src/ic/ic-state.h"
 #include "src/objects.h"
@@ skipping 237 matching lines @@
     int entry_size = TypeFeedbackMetadata::GetSlotSize(kind);
 
     Object* value;
     if (kind == FeedbackVectorSlotKind::LOAD_GLOBAL_IC) {
       value = *factory->empty_weak_cell();
     } else {
       value = *uninitialized_sentinel;
     }
     array->set(index, value, SKIP_WRITE_BARRIER);
     for (int j = 1; j < entry_size; j++) {
-      array->set(index + j, *uninitialized_sentinel, SKIP_WRITE_BARRIER);
+      array->set(index + j, kind == FeedbackVectorSlotKind::CALL_IC

[Benedikt Meurer, 2016/09/13 10:34:58]

Nit: Hoist the value selection out of the loop.

+                                ? Smi::FromInt(0)
+                                : *uninitialized_sentinel,
+                 SKIP_WRITE_BARRIER);
     }
     i += entry_size;
   }
   return Handle<TypeFeedbackVector>::cast(array);
 }
 
 
 // static
 int TypeFeedbackVector::GetIndexFromSpec(const FeedbackVectorSpec* spec,
                                          FeedbackVectorSlot slot) {
@@ skipping 344 matching lines @@
     return MONOMORPHIC;
   }
 
   CHECK(feedback == *TypeFeedbackVector::UninitializedSentinel(isolate));
   return UNINITIALIZED;
 }
 
 
 int CallICNexus::ExtractCallCount() {
   Object* call_count = GetFeedbackExtra();
-  if (call_count->IsSmi()) {
-    int value = Smi::cast(call_count)->value();
-    return value;
-  }
-  return -1;
+  CHECK(call_count->IsSmi());
+  int value = Smi::cast(call_count)->value();
+  return value;
 }
 
-
 void CallICNexus::Clear(Code* host) { CallIC::Clear(GetIsolate(), host, this); }
 
+void CallICNexus::ConfigureUninitialized() {
+  Isolate* isolate = GetIsolate();
+  SetFeedback(*TypeFeedbackVector::UninitializedSentinel(isolate),
+              SKIP_WRITE_BARRIER);
+  SetFeedbackExtra(Smi::FromInt(0), SKIP_WRITE_BARRIER);
+}
 
 void CallICNexus::ConfigureMonomorphicArray() {
   Object* feedback = GetFeedback();
   if (!feedback->IsAllocationSite()) {
     Handle<AllocationSite> new_site =
         GetIsolate()->factory()->NewAllocationSite();
     SetFeedback(*new_site);
   }
   SetFeedbackExtra(Smi::FromInt(1), SKIP_WRITE_BARRIER);
 }
 
 
 void CallICNexus::ConfigureMonomorphic(Handle<JSFunction> function) {
   Handle<WeakCell> new_cell = GetIsolate()->factory()->NewWeakCell(function);
   SetFeedback(*new_cell);
   SetFeedbackExtra(Smi::FromInt(1), SKIP_WRITE_BARRIER);
 }
 
 
 void CallICNexus::ConfigureMegamorphic() {
-  FeedbackNexus::ConfigureMegamorphic();
+  SetFeedback(*TypeFeedbackVector::MegamorphicSentinel(GetIsolate()),
+              SKIP_WRITE_BARRIER);
+  Smi* count = Smi::cast(GetFeedbackExtra());
+  int new_count = count->value() + 1;
+  SetFeedbackExtra(Smi::FromInt(new_count), SKIP_WRITE_BARRIER);
 }
 
-
 void CallICNexus::ConfigureMegamorphic(int call_count) {
   SetFeedback(*TypeFeedbackVector::MegamorphicSentinel(GetIsolate()),
               SKIP_WRITE_BARRIER);
   SetFeedbackExtra(Smi::FromInt(call_count), SKIP_WRITE_BARRIER);
 }
 
 void LoadICNexus::ConfigureMonomorphic(Handle<Map> receiver_map,
                                        Handle<Object> handler) {
   Handle<WeakCell> cell = Map::WeakCellForMap(receiver_map);
   SetFeedback(*cell);
@@ skipping 348 matching lines @@
 
 IcCheckType KeyedStoreICNexus::GetKeyType() const {
   Object* feedback = GetFeedback();
   if (feedback == *TypeFeedbackVector::MegamorphicSentinel(GetIsolate())) {
     return static_cast<IcCheckType>(Smi::cast(GetFeedbackExtra())->value());
   }
   return IsPropertyNameFeedback(feedback) ? PROPERTY : ELEMENT;
 }
 }  // namespace internal
 }  // namespace v8