Revert r3514 and r3515. The new cache is too large for some tests

that attempt to run with a small heap.  Additionally, it can
potentially keep a lot of string data alive and it is never flushed.
Can we make it grow dynamically if used so that we can still start the
VM with a small heap size?
Review URL: http://codereview.chromium.org/503081

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3517 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/heap.cc

@@ -1577,7 +1577,6 @@ bool Heap::CreateInitialObjects() {
   CreateFixedStubs();
 
   // Allocate the number->string conversion cache
-  ASSERT(IsPowerOf2(kNumberStringCacheSize));
   obj = AllocateFixedArray(kNumberStringCacheSize * 2);
   if (obj->IsFailure()) return false;
   set_number_string_cache(FixedArray::cast(obj));
@@ -1611,29 +1610,25 @@ bool Heap::CreateInitialObjects() {
 }
 
 
-static inline int NumberStringTruncateHash(int value) {
-  return (((value >> 16) ^ value)) & (Heap::kNumberStringCacheSize - 1);
-}
-
-
-static inline int DoubleGetHash(double d) {
+static inline int double_get_hash(double d) {
   DoubleRepresentation rep(d);
-  int value = (static_cast<int>(rep.bits) ^ static_cast<int>(rep.bits >> 32));
-  return NumberStringTruncateHash(value);
+  return ((static_cast<int>(rep.bits) ^ static_cast<int>(rep.bits >> 32)) &
+          (Heap::kNumberStringCacheSize - 1));
 }
 
 
-static inline int SmiGetHash(Smi* smi) {
-  return NumberStringTruncateHash(smi->value());
+static inline int smi_get_hash(Smi* smi) {
+  return (smi->value() & (Heap::kNumberStringCacheSize - 1));
 }
 
 
+
 Object* Heap::GetNumberStringCache(Object* number) {
   int hash;
   if (number->IsSmi()) {
-    hash = SmiGetHash(Smi::cast(number));
+    hash = smi_get_hash(Smi::cast(number));
   } else {
-    hash = DoubleGetHash(number->Number());
+    hash = double_get_hash(number->Number());
   }
   Object* key = number_string_cache()->get(hash * 2);
   if (key == number) {
@@ -1650,10 +1645,10 @@ Object* Heap::GetNumberStringCache(Object* number) {
 void Heap::SetNumberStringCache(Object* number, String* string) {
   int hash;
   if (number->IsSmi()) {
-    hash = SmiGetHash(Smi::cast(number));
+    hash = smi_get_hash(Smi::cast(number));
     number_string_cache()->set(hash * 2, number, SKIP_WRITE_BARRIER);
   } else {
-    hash = DoubleGetHash(number->Number());
+    hash = double_get_hash(number->Number());
     number_string_cache()->set(hash * 2, number);
   }
   number_string_cache()->set(hash * 2 + 1, string);

src/heap.h

@@ -821,7 +821,7 @@ class Heap : public AllStatic {
   static void SetNumberStringCache(Object* number, String* str);
 
   // Entries in the cache.  Must be a power of 2.
-  static const int kNumberStringCacheSize = 16*KB;
+  static const int kNumberStringCacheSize = 64;
 
   // Adjusts the amount of registered external memory.
   // Returns the adjusted value.

src/ia32/macro-assembler-ia32.cc

@@ -729,13 +729,13 @@ void MacroAssembler::AllocateInNewSpace(int object_size,
   cmp(result_end, Operand::StaticVariable(new_space_allocation_limit));
   j(above, gc_required, not_taken);
 
+  // Update allocation top.
+  UpdateAllocationTopHelper(result_end, scratch);
+
   // Tag result if requested.
   if ((flags & TAG_OBJECT) != 0) {
     or_(Operand(result), Immediate(kHeapObjectTag));
   }
-
-  // Update allocation top.
-  UpdateAllocationTopHelper(result_end, scratch);
 }
 
 
@@ -759,13 +759,13 @@ void MacroAssembler::AllocateInNewSpace(int header_size,
   cmp(result_end, Operand::StaticVariable(new_space_allocation_limit));
   j(above, gc_required);
 
+  // Update allocation top.
+  UpdateAllocationTopHelper(result_end, scratch);
+
   // Tag result if requested.
   if ((flags & TAG_OBJECT) != 0) {
     or_(Operand(result), Immediate(kHeapObjectTag));
   }
-
-  // Update allocation top.
-  UpdateAllocationTopHelper(result_end, scratch);
 }
 
 
@@ -790,13 +790,13 @@ void MacroAssembler::AllocateInNewSpace(Register object_size,
   cmp(result_end, Operand::StaticVariable(new_space_allocation_limit));
   j(above, gc_required, not_taken);
 
+  // Update allocation top.
+  UpdateAllocationTopHelper(result_end, scratch);
+
   // Tag result if requested.
   if ((flags & TAG_OBJECT) != 0) {
     or_(Operand(result), Immediate(kHeapObjectTag));
   }
-
-  // Update allocation top.
-  UpdateAllocationTopHelper(result_end, scratch);
 }