Avoid unnecessary hashing in OrderedHashTable

src/objects.cc

 // Copyright 2013 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/accessors.h"
 #include "src/allocation-site-scopes.h"
 #include "src/api.h"
 #include "src/arguments.h"
@@ skipping 16122 matching lines @@
 
   new_table->SetNumberOfElements(nof);
   table->SetNextTable(*new_table);
 
   return new_table;
 }
 
 
 template<class Derived, class Iterator, int entrysize>
 int OrderedHashTable<Derived, Iterator, entrysize>::FindEntry(
-    Handle<Object> key) {
+    Handle<Object> key, int hash) {
   ASSERT(!IsObsolete());
 
   DisallowHeapAllocation no_gc;
   ASSERT(!key->IsTheHole());
-  Object* hash = key->GetHash();
-  if (hash->IsUndefined()) return kNotFound;
-  for (int entry = HashToEntry(Smi::cast(hash)->value());
+  for (int entry = HashToEntry(hash);
        entry != kNotFound;
        entry = ChainAt(entry)) {
     Object* candidate = KeyAt(entry);
     if (candidate->SameValueZero(*key))
       return entry;
   }
   return kNotFound;
 }
 
 
 template<class Derived, class Iterator, int entrysize>
+int OrderedHashTable<Derived, Iterator, entrysize>::FindEntry(
+    Handle<Object> key) {
+  DisallowHeapAllocation no_gc;
+  Object* hash = key->GetHash();
+  if (!hash->IsSmi()) return kNotFound;
+  return FindEntry(key, Smi::cast(hash)->value());
+}
+
+
+template<class Derived, class Iterator, int entrysize>
 int OrderedHashTable<Derived, Iterator, entrysize>::AddEntry(int hash) {
   ASSERT(!IsObsolete());
 
   int entry = UsedCapacity();
   int bucket = HashToBucket(hash);
   int index = EntryToIndex(entry);
   Object* chain_entry = get(kHashTableStartIndex + bucket);
   set(kHashTableStartIndex + bucket, Smi::FromInt(entry));
   set(index + kChainOffset, chain_entry);
   SetNumberOfElements(NumberOfElements() + 1);
@@ skipping 29 matching lines @@
 template Handle<OrderedHashSet>
 OrderedHashTable<OrderedHashSet, JSSetIterator, 1>::Clear(
     Handle<OrderedHashSet> table);
 
 template Handle<OrderedHashSet>
 OrderedHashTable<OrderedHashSet, JSSetIterator, 1>::Remove(
     Handle<OrderedHashSet> table, Handle<Object> key, bool* was_present);
 
 template int
 OrderedHashTable<OrderedHashSet, JSSetIterator, 1>::FindEntry(
+    Handle<Object> key, int hash);
+template int
+OrderedHashTable<OrderedHashSet, JSSetIterator, 1>::FindEntry(
     Handle<Object> key);
 
 template int
 OrderedHashTable<OrderedHashSet, JSSetIterator, 1>::AddEntry(int hash);
 
 template void
 OrderedHashTable<OrderedHashSet, JSSetIterator, 1>::RemoveEntry(int entry);
 
 
 template Handle<OrderedHashMap>
@@ skipping 11 matching lines @@
 template Handle<OrderedHashMap>
 OrderedHashTable<OrderedHashMap, JSMapIterator, 2>::Clear(
     Handle<OrderedHashMap> table);
 
 template Handle<OrderedHashMap>
 OrderedHashTable<OrderedHashMap, JSMapIterator, 2>::Remove(
     Handle<OrderedHashMap> table, Handle<Object> key, bool* was_present);
 
 template int
 OrderedHashTable<OrderedHashMap, JSMapIterator, 2>::FindEntry(
+    Handle<Object> key, int hash);
+template int
+OrderedHashTable<OrderedHashMap, JSMapIterator, 2>::FindEntry(
     Handle<Object> key);
 
 template int
 OrderedHashTable<OrderedHashMap, JSMapIterator, 2>::AddEntry(int hash);
 
 template void
 OrderedHashTable<OrderedHashMap, JSMapIterator, 2>::RemoveEntry(int entry);
 
 
 bool OrderedHashSet::Contains(Handle<Object> key) {
   return FindEntry(key) != kNotFound;
 }
 
 
 Handle<OrderedHashSet> OrderedHashSet::Add(Handle<OrderedHashSet> table,
                                            Handle<Object> key) {
-  if (table->FindEntry(key) != kNotFound) return table;
+  int hash = GetOrCreateHash(table->GetIsolate(), key)->value();
+  if (table->FindEntry(key, hash) != kNotFound) return table;
 
   table = EnsureGrowable(table);
 
-  Handle<Smi> hash = GetOrCreateHash(table->GetIsolate(), key);
-  int index = table->AddEntry(hash->value());
+  int index = table->AddEntry(hash);
   table->set(index, *key);
   return table;
 }
 
 
 Object* OrderedHashMap::Lookup(Handle<Object> key) {
   DisallowHeapAllocation no_gc;
   int entry = FindEntry(key);
   if (entry == kNotFound) return GetHeap()->the_hole_value();
   return ValueAt(entry);
 }
 
 
 Handle<OrderedHashMap> OrderedHashMap::Put(Handle<OrderedHashMap> table,
                                            Handle<Object> key,
                                            Handle<Object> value) {
   ASSERT(!key->IsTheHole());
 
-  int entry = table->FindEntry(key);
+  int hash = GetOrCreateHash(table->GetIsolate(), key)->value();
+  int entry = table->FindEntry(key, hash);
 
   if (entry != kNotFound) {
     table->set(table->EntryToIndex(entry) + kValueOffset, *value);
     return table;
   }
 
   table = EnsureGrowable(table);
 
-  Handle<Smi> hash = GetOrCreateHash(table->GetIsolate(), key);
-  int index = table->AddEntry(hash->value());
+  int index = table->AddEntry(hash);
   table->set(index, *key);
   table->set(index + kValueOffset, *value);
   return table;
 }
 
 
 template<class Derived, class TableType>
 void OrderedHashTableIterator<Derived, TableType>::Transition() {
   DisallowHeapAllocation no_allocation;
   TableType* table = TableType::cast(this->table());
@@ skipping 683 matching lines @@
 #define ERROR_MESSAGES_TEXTS(C, T) T,
   static const char* error_messages_[] = {
       ERROR_MESSAGES_LIST(ERROR_MESSAGES_TEXTS)
   };
 #undef ERROR_MESSAGES_TEXTS
   return error_messages_[reason];
 }
 
 
 } }  // namespace v8::internal