Simplify/speedup collecting dictionary element keys

src/elements.cc

Index: src/elements.cc
diff --git a/src/elements.cc b/src/elements.cc
index 2ec224c23efd64dc20742affd427db546a8e3092..7746d8df07d71f3de4fd29f3b09301a3b497ab63 100644
--- a/src/elements.cc
+++ b/src/elements.cc
@@ -839,6 +839,7 @@ class ElementsAccessorBase : public ElementsAccessor {
                              Handle<FixedArrayBase> backing_store,
                              KeyAccumulator* keys, uint32_t range,
                              PropertyFilter filter, uint32_t offset) final {
+    if (filter & ONLY_ALL_CAN_READ) return;
     ElementsAccessorSubclass::CollectElementIndicesImpl(
         object, backing_store, keys, range, filter, offset);
   }
@@ -849,10 +850,7 @@ class ElementsAccessorBase : public ElementsAccessor {
                                         PropertyFilter filter,
                                         uint32_t offset) {
     DCHECK_NE(DICTIONARY_ELEMENTS, kind());
-    if (filter & ONLY_ALL_CAN_READ) {
-      // Non-dictionary elements can't have all-can-read accessors.
-      return;
-    }
+    // Non-dictionary elements can't have all-can-read accessors.
     uint32_t length = GetIterationLength(*object, *backing_store);
     if (range < length) length = range;
     for (uint32_t i = offset; i < length; i++) {
@@ -1190,21 +1188,13 @@ class DictionaryElementsAccessor
     DisallowHeapAllocation no_gc;
     Object* raw_key = dictionary->KeyAt(entry);
     if (!dictionary->IsKey(raw_key)) return kMaxUInt32;
-    if (raw_key->FilterKey(filter)) return kMaxUInt32;
-    if (dictionary->IsDeleted(entry)) return kMaxUInt32;
+    DCHECK(!dictionary->IsDeleted(entry));
     DCHECK(raw_key->IsNumber());
     DCHECK_LE(raw_key->Number(), kMaxUInt32);
-    uint32_t key = static_cast<uint32_t>(raw_key->Number());
     PropertyDetails details = dictionary->DetailsAt(entry);
-    if (filter & ONLY_ALL_CAN_READ) {
-      if (details.kind() != kAccessor) return kMaxUInt32;
-      Object* accessors = dictionary->ValueAt(entry);
-      if (!accessors->IsAccessorInfo()) return kMaxUInt32;
-      if (!AccessorInfo::cast(accessors)->all_can_read()) return kMaxUInt32;
-    }
     PropertyAttributes attr = details.attributes();
     if ((attr & filter) != 0) return kMaxUInt32;
-    return key;
+    return static_cast<uint32_t>(raw_key->Number());
   }
 
   static void CollectElementIndicesImpl(Handle<JSObject> object,
@@ -1212,6 +1202,7 @@ class DictionaryElementsAccessor
                                         KeyAccumulator* keys, uint32_t range,
                                         PropertyFilter filter,
                                         uint32_t offset) {
+    if (filter & SKIP_STRINGS) return;
     Handle<SeededNumberDictionary> dictionary =
         Handle<SeededNumberDictionary>::cast(backing_store);
     int capacity = dictionary->Capacity();
@@ -1229,6 +1220,8 @@ class DictionaryElementsAccessor
       Handle<FixedArrayBase> backing_store, GetKeysConversion convert,
       PropertyFilter filter, Handle<FixedArray> list, uint32_t* nof_indices,
       uint32_t insertion_index = 0) {
+    if (filter & SKIP_STRINGS) return list;
+    if (filter & ONLY_ALL_CAN_READ) return list;
     Handle<SeededNumberDictionary> dictionary =
         Handle<SeededNumberDictionary>::cast(backing_store);
     uint32_t capacity = dictionary->Capacity();
@@ -2561,11 +2554,9 @@ class StringWrapperElementsAccessor
                                         KeyAccumulator* keys, uint32_t range,
                                         PropertyFilter filter,
                                         uint32_t offset) {
-    if ((filter & ONLY_ALL_CAN_READ) == 0) {
-      uint32_t length = GetString(*object)->length();
-      for (uint32_t i = 0; i < length; i++) {
-        keys->AddKey(i);
-      }
+    uint32_t length = GetString(*object)->length();
+    for (uint32_t i = 0; i < length; i++) {
+      keys->AddKey(i);
     }
     BackingStoreAccessor::CollectElementIndicesImpl(object, backing_store, keys,
                                                     range, filter, offset);