Retry "Use a WeakCell in the CallIC type vector."

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/v8.h"
 
 #include "src/ic/ic.h"
 #include "src/ic/ic-state.h"
 #include "src/objects.h"
 #include "src/type-feedback-vector-inl.h"
@@ skipping 114 matching lines @@
     Isolate* isolate, Handle<TypeFeedbackVector> vector) {
   Handle<TypeFeedbackVector> result;
   result = Handle<TypeFeedbackVector>::cast(
       isolate->factory()->CopyFixedArray(Handle<FixedArray>::cast(vector)));
   return result;
 }
 
 
 // This logic is copied from
 // StaticMarkingVisitor<StaticVisitor>::VisitCodeTarget.
-// TODO(mvstanton): with weak handling of all vector ics, this logic should
-// actually be completely eliminated and we no longer need to clear the
-// vector ICs.
-static bool ClearLogic(Heap* heap, int ic_age, Code::Kind kind,
-                       InlineCacheState state) {
+static bool ClearLogic(Heap* heap, int ic_age) {
   if (FLAG_cleanup_code_caches_at_gc &&
-      (kind == Code::CALL_IC || heap->flush_monomorphic_ics() ||
+      (heap->flush_monomorphic_ics() ||
        // TODO(mvstanton): is this ic_age granular enough? it comes from
        // the SharedFunctionInfo which may change on a different schedule
        // than ic targets.
        // ic_age != heap->global_ic_age() ||
        // is_invalidated_weak_stub ||
        heap->isolate()->serializer_enabled())) {
     return true;
   }
   return false;
 }
@@ skipping 12 matching lines @@
       InstanceType instance_type =
           HeapObject::cast(obj)->map()->instance_type();
       // AllocationSites are exempt from clearing. They don't store Maps
       // or Code pointers which can cause memory leaks if not cleared
       // regularly.
       if (instance_type != ALLOCATION_SITE_TYPE) {
         Set(slot, uninitialized_sentinel, SKIP_WRITE_BARRIER);
       }
     }
   }
+}
 
-  slots = ICSlots();
-  if (slots == 0) return;
 
-  // Now clear vector-based ICs.
-  // Try and pass the containing code (the "host").
-  Heap* heap = isolate->heap();
-  Code* host = shared->code();
+void TypeFeedbackVector::ClearICSlotsImpl(SharedFunctionInfo* shared,
+                                          bool force_clear) {
+  Heap* heap = GetIsolate()->heap();
+
   // I'm not sure yet if this ic age is the correct one.
   int ic_age = shared->ic_age();
+
+  if (!force_clear && !ClearLogic(heap, ic_age)) return;
+
+  int slots = ICSlots();
+  Code* host = shared->code();
+  Object* uninitialized_sentinel =
+      TypeFeedbackVector::RawUninitializedSentinel(heap);
   for (int i = 0; i < slots; i++) {
     FeedbackVectorICSlot slot(i);
     Object* obj = Get(slot);
     if (obj != uninitialized_sentinel) {
       Code::Kind kind = GetKind(slot);
       if (kind == Code::CALL_IC) {
         CallICNexus nexus(this, slot);
-        if (ClearLogic(heap, ic_age, kind, nexus.StateFromFeedback())) {
-          nexus.Clear(host);
-        }
+        nexus.Clear(host);
       } else if (kind == Code::LOAD_IC) {
         LoadICNexus nexus(this, slot);
-        if (ClearLogic(heap, ic_age, kind, nexus.StateFromFeedback())) {
-          nexus.Clear(host);
-        }
+        nexus.Clear(host);
       } else if (kind == Code::KEYED_LOAD_IC) {
         KeyedLoadICNexus nexus(this, slot);
-        if (ClearLogic(heap, ic_age, kind, nexus.StateFromFeedback())) {
-          nexus.Clear(host);
-        }
+        nexus.Clear(host);
       }
     }
   }
 }
 
 
 Handle<FixedArray> FeedbackNexus::EnsureArrayOfSize(int length) {
   Isolate* isolate = GetIsolate();
   Handle<Object> feedback = handle(GetFeedback(), isolate);
   if (!feedback->IsFixedArray() ||
@@ skipping 64 matching lines @@
   return UNINITIALIZED;
 }
 
 
 InlineCacheState CallICNexus::StateFromFeedback() const {
   Isolate* isolate = GetIsolate();
   Object* feedback = GetFeedback();
 
   if (feedback == *vector()->MegamorphicSentinel(isolate)) {
     return GENERIC;
-  } else if (feedback->IsAllocationSite() || feedback->IsJSFunction()) {
+  } else if (feedback->IsAllocationSite() || feedback->IsWeakCell()) {
     return MONOMORPHIC;
   }
 
   CHECK(feedback == *vector()->UninitializedSentinel(isolate));
   return UNINITIALIZED;
 }
 
 
 void CallICNexus::Clear(Code* host) { CallIC::Clear(GetIsolate(), host, this); }
 
@@ skipping 13 matching lines @@
 }
 
 
 void CallICNexus::ConfigureUninitialized() {
   SetFeedback(*vector()->UninitializedSentinel(GetIsolate()),
               SKIP_WRITE_BARRIER);
 }
 
 
 void CallICNexus::ConfigureMonomorphic(Handle<JSFunction> function) {
-  SetFeedback(*function);
+  Handle<WeakCell> new_cell = GetIsolate()->factory()->NewWeakCell(function);
+  SetFeedback(*new_cell);
 }
 
 
 void KeyedLoadICNexus::ConfigureMegamorphic() {
   SetFeedback(*vector()->MegamorphicSentinel(GetIsolate()), SKIP_WRITE_BARRIER);
 }
 
 
 void LoadICNexus::ConfigureMegamorphic() {
   SetFeedback(*vector()->MegamorphicSentinel(GetIsolate()), SKIP_WRITE_BARRIER);
@@ skipping 174 matching lines @@
   if (feedback->IsFixedArray()) {
     FixedArray* array = FixedArray::cast(feedback);
     DCHECK(array->length() >= 3);
     Object* name = array->get(0);
     if (name->IsName()) return Name::cast(name);
   }
   return NULL;
 }
 }
 }  // namespace v8::internal