[compiler] Move GetStrongValue to DescriptorArrayRef

Also access the DescriptorArray through GetStrongValue concurrently if
the FLAG_turbo_direct_heap_access is on.

Bug: v8:7790
Change-Id: I7a36789b44e84988d498339312bf9fe92eab8e66
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2653233Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72549}

src/compiler/heap-refs.h

@@ -547,6 +547,8 @@ class DescriptorArrayRef : public HeapObjectRef {
 
   PropertyDetails GetPropertyDetails(InternalIndex descriptor_index) const;
   NameRef GetPropertyKey(InternalIndex descriptor_index) const;
+  base::Optional<ObjectRef> GetStrongValue(
+      InternalIndex descriptor_index) const;
 };
 
 class FeedbackCellRef : public HeapObjectRef {

src/compiler/js-heap-broker.cc

@@ -3658,24 +3658,7 @@ base::Optional<FeedbackVectorRef> FeedbackCellRef::value() const {
 base::Optional<ObjectRef> MapRef::GetStrongValue(
     InternalIndex descriptor_index) const {
   CHECK_LT(descriptor_index.as_int(), NumberOfOwnDescriptors());
-  if (data_->should_access_heap()) {
-    MaybeObject value =
-        object()->instance_descriptors(kRelaxedLoad).GetValue(descriptor_index);
-    HeapObject object;
-    if (value.GetHeapObjectIfStrong(&object)) {
-      return ObjectRef(broker(), broker()->CanonicalPersistentHandle((object)));
-    }
-    return base::nullopt;
-  }
-  ObjectData* value = data()
-                          ->AsMap()
-                          ->instance_descriptors()
-                          ->AsDescriptorArray()
-                          ->GetStrongValue(descriptor_index);
-  if (!value) {
-    return base::nullopt;
-  }
-  return ObjectRef(broker(), value);
+  return instance_descriptors().GetStrongValue(descriptor_index);
 }
 
 DescriptorArrayRef MapRef::instance_descriptors() const {
@@ -4093,6 +4076,33 @@ NameRef DescriptorArrayRef::GetPropertyKey(
                  data()->AsDescriptorArray()->GetPropertyKey(descriptor_index));
 }
 
+base::Optional<ObjectRef> DescriptorArrayRef::GetStrongValue(
+    InternalIndex descriptor_index) const {
+  if (data_->should_access_heap() || FLAG_turbo_direct_heap_access) {
+    HeapObject heap_object;
+    if (object()
+            ->GetValue(descriptor_index)
+            .GetHeapObjectIfStrong(&heap_object)) {
+      // Since the descriptors in the descriptor array can be changed in-place
+      // via DescriptorArray::Replace, we might get a value that we haven't seen
+      // before.
+      ObjectData* data = broker()->TryGetOrCreateData(
+          broker()->CanonicalPersistentHandle(heap_object));
+      if (data) return ObjectRef(broker(), data);
+
+      TRACE_BROKER_MISSING(broker(), "strong value for descriptor array "
+                                         << *this << " at index "
+                                         << descriptor_index.as_int());
+      // Fall through to the base::nullopt below.
+    }
+    return base::nullopt;
+  }
+  ObjectData* value =
+      data()->AsDescriptorArray()->GetStrongValue(descriptor_index);
+  if (!value) return base::nullopt;
+  return ObjectRef(broker(), value);
+}
+
 base::Optional<SharedFunctionInfoRef> FeedbackCellRef::shared_function_info()
     const {
   if (value()) {