- Changed the initial size for HashTable....

src/objects.cc

Index: src/objects.cc
===================================================================
--- src/objects.cc	(revision 4009)
+++ src/objects.cc	(working copy)
@@ -6904,15 +6904,16 @@
 
 
 template<typename Shape, typename Key>
-Object* HashTable<Shape, Key>::Allocate(int at_least_space_for) {
-  int capacity = RoundUpToPowerOf2(at_least_space_for);
-  if (capacity < 4) {
-    capacity = 4;  // Guarantee min capacity.
+Object* HashTable<Shape, Key>::Allocate(int at_least_space_for,
+                                        PretenureFlag pretenure) {
+  int capacity = RoundUpToPowerOf2(at_least_space_for * 2);
+  if (capacity < 32) {
+    capacity = 32; // Guarantee min capacity.
   } else if (capacity > HashTable::kMaxCapacity) {
     return Failure::OutOfMemoryException();
   }
 
-  Object* obj = Heap::AllocateHashTable(EntryToIndex(capacity));
+  Object* obj = Heap::AllocateHashTable(EntryToIndex(capacity), pretenure);
   if (!obj->IsFailure()) {
     HashTable::cast(obj)->SetNumberOfElements(0);
     HashTable::cast(obj)->SetNumberOfDeletedElements(0);
@@ -6947,10 +6948,15 @@
   // Return if:
   //   25% is still free after adding n elements and

[Kasper Lund, 2010/03/03 16:01:06]

Update comment to reflect 50%.

[bak, 2010/03/03 16:18:26]

Done.

   //   at most 50% of the free elements are deleted elements.
-  if ((nof + (nof >> 2) <= capacity) &&
-      (nod <= (capacity - nof) >> 1)) return this;
+  if (nod <= (capacity - nof) >> 1) {
+    int needed_free = nof >> 1;
+    if (nof + needed_free <= capacity) return this;
+  }
 
-  Object* obj = Allocate(nof * 2);
+  const int kMinCapacityForPreTenure = 256;

[Kasper Lund, 2010/03/03 16:01:06]

PreTenure -> Pretenure (to match the rest of the code). Maybe this should be
kMaxCapacityForNonTenured? You can have pretenured hash tables with a smaller
capacity than this.

[bak, 2010/03/03 16:18:26]

I changed the uppercase issue.

+  bool pretenure =
+      (capacity > kMinCapacityForPreTenure) && !Heap::InNewSpace(this);
+  Object* obj = Allocate(nof * 2, pretenure ? TENURED : NOT_TENURED);
   if (obj->IsFailure()) return obj;
 
   AssertNoAllocation no_gc;