Revert 10502 (smaller number string cache) due to test failures.

src/heap.cc

Index: src/heap.cc
===================================================================
--- src/heap.cc	(revision 10502)
+++ src/heap.cc	(working copy)
@@ -902,7 +902,8 @@
 
   CompletelyClearInstanceofCache();
 
-  FlushNumberStringCache();
+  // TODO(1605) select heuristic for flushing NumberString cache with
+  // FlushNumberStringCache
   if (FLAG_cleanup_code_caches_at_gc) {
     polymorphic_code_cache()->set_cache(undefined_value());
   }
@@ -2511,10 +2512,7 @@
   }
   set_intrinsic_function_names(StringDictionary::cast(obj));
 
-  { MaybeObject* maybe_obj = AllocateInitialNumberStringCache();
-    if (!maybe_obj->ToObject(&obj)) return false;
-  }
-  set_number_string_cache(FixedArray::cast(obj));
+  if (InitializeNumberStringCache()->IsFailure()) return false;
 
   // Allocate cache for single character ASCII strings.
   { MaybeObject* maybe_obj =
@@ -2624,44 +2622,20 @@
 }
 
 
-MaybeObject* Heap::AllocateInitialNumberStringCache() {
+MaybeObject* Heap::InitializeNumberStringCache() {
+  // Compute the size of the number string cache based on the max heap size.
+  // max_semispace_size_ == 512 KB => number_string_cache_size = 32.
+  // max_semispace_size_ ==   8 MB => number_string_cache_size = 16KB.
+  int number_string_cache_size = max_semispace_size_ / 512;
+  number_string_cache_size = Max(32, Min(16*KB, number_string_cache_size));
+  Object* obj;
   MaybeObject* maybe_obj =
-      AllocateFixedArray(kInitialNumberStringCacheSize * 2, TENURED);
+      AllocateFixedArray(number_string_cache_size * 2, TENURED);
+  if (maybe_obj->ToObject(&obj)) set_number_string_cache(FixedArray::cast(obj));
   return maybe_obj;
 }
 
 
-int Heap::FullSizeNumberStringCacheLength() {
-  // Compute the size of the number string cache based on the max newspace size.
-  // The number string cache has a minimum size based on twice the initial cache
-  // size to ensure that it is bigger after being made 'full size'.
-  int number_string_cache_size = max_semispace_size_ / 512;
-  number_string_cache_size = Max(kInitialNumberStringCacheSize * 2,
-                                 Min(0x4000, number_string_cache_size));
-  // There is a string and a number per entry so the length is twice the number
-  // of entries.
-  return number_string_cache_size * 2;
-}
-
-
-void Heap::AllocateFullSizeNumberStringCache() {
-  // The idea is to have a small number string cache in the snapshot to keep
-  // boot-time memory usage down.  If we expand the number string cache already
-  // while creating the snapshot then that didn't work out.
-  ASSERT(!Serializer::enabled());
-  MaybeObject* maybe_obj =
-      AllocateFixedArray(FullSizeNumberStringCacheLength(), TENURED);
-  Object* new_cache;
-  if (maybe_obj->ToObject(&new_cache)) {
-    // We don't bother to repopulate the cache with entries from the old cache.
-    // It will be repopulated soon enough with new strings.
-    set_number_string_cache(FixedArray::cast(new_cache));
-  }
-  // If allocation fails then we just return without doing anything.  It is only
-  // a cache, so best effort is OK here.
-}
-
-
 void Heap::FlushNumberStringCache() {
   // Flush the number to string cache.
   int len = number_string_cache()->length();
@@ -2707,17 +2681,11 @@
   int mask = (number_string_cache()->length() >> 1) - 1;
   if (number->IsSmi()) {
     hash = smi_get_hash(Smi::cast(number)) & mask;
+    number_string_cache()->set(hash * 2, Smi::cast(number));
   } else {
     hash = double_get_hash(number->Number()) & mask;
+    number_string_cache()->set(hash * 2, number);
   }
-  if (number_string_cache()->get(hash * 2) != undefined_value() &&
-      number_string_cache()->length() != FullSizeNumberStringCacheLength()) {
-    // The first time we have a hash collision, we move to the full sized
-    // number string cache.
-    AllocateFullSizeNumberStringCache();
-    return;
-  }
-  number_string_cache()->set(hash * 2, number);
   number_string_cache()->set(hash * 2 + 1, string);
 }