Remove flush_monomorphic_ics flag.

Since v8:3629 is fixed, ICs and handlers do not retain objects.

Review URL: https://codereview.chromium.org/880253007

Cr-Commit-Position: refs/heads/master@{#26455}

src/heap/heap.cc

@@ -81,7 +81,6 @@ Heap::Heap()
       always_allocate_scope_depth_(0),
       contexts_disposed_(0),
       global_ic_age_(0),
-      flush_monomorphic_ics_(false),
       scan_on_scavenge_pages_(0),
       new_space_(this),
       old_pointer_space_(NULL),
@@ -880,7 +879,6 @@ int Heap::NotifyContextDisposed(bool dependant_context) {
     // Flush the queued recompilation tasks.
     isolate()->optimizing_compiler_thread()->Flush();
   }
-  flush_monomorphic_ics_ = true;
   AgeInlineCaches();
   tracer()->AddContextDisposalTime(base::OS::TimeCurrentMillis());
   return ++contexts_disposed_;
@@ -1248,8 +1246,6 @@ void Heap::MarkCompactEpilogue() {
 
   isolate_->counters()->objs_since_last_full()->Set(0);
 
-  flush_monomorphic_ics_ = false;
-
   incremental_marking()->Epilogue();
 }
 

src/heap/heap.h

@@ -1351,8 +1351,6 @@ class Heap {
     global_ic_age_ = (global_ic_age_ + 1) & SharedFunctionInfo::ICAgeBits::kMax;
   }
 
-  bool flush_monomorphic_ics() { return flush_monomorphic_ics_; }
-
   int64_t amount_of_external_allocated_memory() {
     return amount_of_external_allocated_memory_;
   }
@@ -1539,8 +1537,6 @@ class Heap {
 
   int global_ic_age_;
 
-  bool flush_monomorphic_ics_;
-
   int scan_on_scavenge_pages_;
 
   NewSpace new_space_;

src/heap/objects-visiting-inl.h

@@ -262,10 +262,8 @@ void StaticMarkingVisitor<StaticVisitor>::VisitCodeTarget(Heap* heap,
   // when they might be keeping a Context alive, or when the heap is about
   // to be serialized.
   if (FLAG_cleanup_code_caches_at_gc && target->is_inline_cache_stub() &&
-      !target->is_call_stub() &&
-      ((heap->flush_monomorphic_ics() && !target->embeds_maps_weakly()) ||
-       heap->isolate()->serializer_enabled() ||
-       target->ic_age() != heap->global_ic_age())) {
+      !target->is_call_stub() && (heap->isolate()->serializer_enabled() ||
+                                  target->ic_age() != heap->global_ic_age())) {
     ICUtility::Clear(heap->isolate(), rinfo->pc(),
                      rinfo->host()->constant_pool());
     target = Code::GetCodeFromTargetAddress(rinfo->target_address());

src/type-feedback-vector.cc

@@ -133,17 +133,8 @@ Handle<TypeFeedbackVector> TypeFeedbackVector::Copy(
 // This logic is copied from
 // StaticMarkingVisitor<StaticVisitor>::VisitCodeTarget.
 static bool ClearLogic(Heap* heap, int ic_age) {
-  if (FLAG_cleanup_code_caches_at_gc &&
-      (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;
+  return FLAG_cleanup_code_caches_at_gc &&
+         heap->isolate()->serializer_enabled();
 }