Implement tracking and optimizations of packed arrays

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index 22993f25689011328c0fb2ced90bad4ba57d1689..2373e54707d74456a35ee48c173054ae6b07e9bc 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -30,6 +30,7 @@
 
 #include "allocation.h"
 #include "builtins.h"
+#include "elements-kind.h"
 #include "list.h"
 #include "property-details.h"
 #include "smart-array-pointer.h"
@@ -131,40 +132,6 @@
 namespace v8 {
 namespace internal {
 
-enum ElementsKind {
-  // The "fast" kind for elements that only contain SMI values. Must be first
-  // to make it possible to efficiently check maps for this kind.
-  FAST_SMI_ONLY_ELEMENTS,
-
-  // The "fast" kind for tagged values. Must be second to make it possible to
-  // efficiently check maps for this and the FAST_SMI_ONLY_ELEMENTS kind
-  // together at once.
-  FAST_ELEMENTS,
-
-  // The "fast" kind for unwrapped, non-tagged double values.
-  FAST_DOUBLE_ELEMENTS,
-
-  // The "slow" kind.
-  DICTIONARY_ELEMENTS,
-  NON_STRICT_ARGUMENTS_ELEMENTS,
-  // The "fast" kind for external arrays
-  EXTERNAL_BYTE_ELEMENTS,
-  EXTERNAL_UNSIGNED_BYTE_ELEMENTS,
-  EXTERNAL_SHORT_ELEMENTS,
-  EXTERNAL_UNSIGNED_SHORT_ELEMENTS,
-  EXTERNAL_INT_ELEMENTS,
-  EXTERNAL_UNSIGNED_INT_ELEMENTS,
-  EXTERNAL_FLOAT_ELEMENTS,
-  EXTERNAL_DOUBLE_ELEMENTS,
-  EXTERNAL_PIXEL_ELEMENTS,
-
-  // Derived constants from ElementsKind
-  FIRST_EXTERNAL_ARRAY_ELEMENTS_KIND = EXTERNAL_BYTE_ELEMENTS,
-  LAST_EXTERNAL_ARRAY_ELEMENTS_KIND = EXTERNAL_PIXEL_ELEMENTS,
-  FIRST_ELEMENTS_KIND = FAST_SMI_ONLY_ELEMENTS,
-  LAST_ELEMENTS_KIND = EXTERNAL_PIXEL_ELEMENTS
-};
-
 enum CompareMapMode {
   REQUIRE_EXACT_MAP,
   ALLOW_ELEMENT_TRANSITION_MAPS
@@ -175,13 +142,6 @@ enum KeyedAccessGrowMode {
   ALLOW_JSARRAY_GROWTH
 };
 
-const int kElementsKindCount = LAST_ELEMENTS_KIND - FIRST_ELEMENTS_KIND + 1;
-
-void PrintElementsKind(FILE* out, ElementsKind kind);
-
-inline bool IsMoreGeneralElementsKindTransition(ElementsKind from_kind,
-                                                ElementsKind to_kind);
-
 // Setter that skips the write barrier if mode is SKIP_WRITE_BARRIER.
 enum WriteBarrierMode { SKIP_WRITE_BARRIER, UPDATE_WRITE_BARRIER };
 
@@ -1510,13 +1470,19 @@ class JSObject: public JSReceiver {
   MUST_USE_RESULT inline MaybeObject* ResetElements();
   inline ElementsKind GetElementsKind();
   inline ElementsAccessor* GetElementsAccessor();
-  inline bool HasFastSmiOnlyElements();
-  inline bool HasFastElements();
-  // Returns if an object has either FAST_ELEMENT or FAST_SMI_ONLY_ELEMENT
-  // elements.  TODO(danno): Rename HasFastTypeElements to HasFastElements() and
-  // HasFastElements to HasFastObjectElements.
-  inline bool HasFastTypeElements();
+  // Returns true if an object has elements of FAST_SMI_ELEMENTS ElementsKind.
+  inline bool HasFastSmiElements();
+  // Returns true if an object has elements of FAST_ELEMENTS ElementsKind.
+  inline bool HasFastObjectElements();
+  // Returns true if an object has elements of FAST_ELEMENTS or
+  // FAST_SMI_ONLY_ELEMENTS.
+  inline bool HasFastSmiOrObjectElements();
+  // Returns true if an object has elements of FAST_DOUBLE_ELEMENTS
+  // ElementsKind.
   inline bool HasFastDoubleElements();
+  // Returns true if an object has elements of FAST_HOLEY_*_ELEMENTS
+  // ElementsKind.
+  inline bool HasFastHoleyElements();
   inline bool HasNonStrictArgumentsElements();
   inline bool HasDictionaryElements();
   inline bool HasExternalPixelElements();
@@ -1719,7 +1685,7 @@ class JSObject: public JSReceiver {
   static Handle<Object> DeleteElement(Handle<JSObject> obj, uint32_t index);
   MUST_USE_RESULT MaybeObject* DeleteElement(uint32_t index, DeleteMode mode);
 
-  inline void ValidateSmiOnlyElements();
+  inline void ValidateElements();
 
   // Makes sure that this object can contain HeapObject as elements.
   MUST_USE_RESULT inline MaybeObject* EnsureCanContainHeapObjectElements();
@@ -1731,6 +1697,7 @@ class JSObject: public JSReceiver {
       EnsureElementsMode mode);
   MUST_USE_RESULT inline MaybeObject* EnsureCanContainElements(
       FixedArrayBase* elements,
+      uint32_t length,
       EnsureElementsMode mode);
   MUST_USE_RESULT MaybeObject* EnsureCanContainElements(
       Arguments* arguments,
@@ -1829,10 +1796,10 @@ class JSObject: public JSReceiver {
   MUST_USE_RESULT MaybeObject* GetElementWithInterceptor(Object* receiver,
                                                          uint32_t index);
 
-  enum SetFastElementsCapacityMode {
-    kAllowSmiOnlyElements,
-    kForceSmiOnlyElements,
-    kDontAllowSmiOnlyElements
+  enum SetFastElementsCapacitySmiMode {
+    kAllowSmiElements,
+    kForceSmiElements,
+    kDontAllowSmiElements
   };
 
   // Replace the elements' backing store with fast elements of the given
@@ -1841,7 +1808,7 @@ class JSObject: public JSReceiver {
   MUST_USE_RESULT MaybeObject* SetFastElementsCapacityAndLength(
       int capacity,
       int length,
-      SetFastElementsCapacityMode set_capacity_mode);
+      SetFastElementsCapacitySmiMode smi_mode);
   MUST_USE_RESULT MaybeObject* SetFastDoubleElementsCapacityAndLength(
       int capacity,
       int length);
@@ -4647,17 +4614,21 @@ class Map: public HeapObject {
   }
 
   // Tells whether the instance has fast elements that are only Smis.
-  inline bool has_fast_smi_only_elements() {
-    return elements_kind() == FAST_SMI_ONLY_ELEMENTS;
+  inline bool has_fast_smi_elements() {
+    return IsFastSmiElementsKind(elements_kind());
   }
 
   // Tells whether the instance has fast elements.
-  inline bool has_fast_elements() {
-    return elements_kind() == FAST_ELEMENTS;
+  inline bool has_fast_object_elements() {
+    return IsFastObjectElementsKind(elements_kind());
+  }
+
+  inline bool has_fast_smi_or_object_elements() {
+    return IsFastSmiOrObjectElementsKind(elements_kind());
   }
 
   inline bool has_fast_double_elements() {
-    return elements_kind() == FAST_DOUBLE_ELEMENTS;
+    return IsFastDoubleElementsKind(elements_kind());
   }
 
   inline bool has_non_strict_arguments_elements() {
@@ -4945,25 +4916,31 @@ class Map: public HeapObject {
 
   // Bit positions for bit field 2
   static const int kIsExtensible = 0;
-  static const int kFunctionWithPrototype = 1;
-  static const int kStringWrapperSafeForDefaultValueOf = 2;
-  static const int kAttachedToSharedFunctionInfo = 3;
+  static const int kStringWrapperSafeForDefaultValueOf = 1;
+  static const int kAttachedToSharedFunctionInfo = 2;
   // No bits can be used after kElementsKindFirstBit, they are all reserved for
   // storing ElementKind.
-  static const int kElementsKindShift = 4;
-  static const int kElementsKindBitCount = 4;
+  static const int kElementsKindShift = 3;
+  static const int kElementsKindBitCount = 5;
 
   // Derived values from bit field 2
   static const int kElementsKindMask = (-1 << kElementsKindShift) &
       ((1 << (kElementsKindShift + kElementsKindBitCount)) - 1);
   static const int8_t kMaximumBitField2FastElementValue = static_cast<int8_t>(
       (FAST_ELEMENTS + 1) << Map::kElementsKindShift) - 1;
-  static const int8_t kMaximumBitField2FastSmiOnlyElementValue =
-      static_cast<int8_t>((FAST_SMI_ONLY_ELEMENTS + 1) <<
+  static const int8_t kMaximumBitField2FastSmiElementValue =
+      static_cast<int8_t>((FAST_SMI_ELEMENTS + 1) <<
+                          Map::kElementsKindShift) - 1;
+  static const int8_t kMaximumBitField2FastHoleyElementValue =
+      static_cast<int8_t>((FAST_HOLEY_ELEMENTS + 1) <<
+                          Map::kElementsKindShift) - 1;
+  static const int8_t kMaximumBitField2FastHoleySmiElementValue =
+      static_cast<int8_t>((FAST_HOLEY_SMI_ELEMENTS + 1) <<
                           Map::kElementsKindShift) - 1;
 
   // Bit positions for bit field 3
   static const int kIsShared = 0;
+  static const int kFunctionWithPrototype = 1;
 
   // Layout of the default cache. It holds alternating name and code objects.
   static const int kCodeCacheEntrySize = 2;