Cache maps for externalized typed array objects.

After this, the maps do not garbage-collect, and typed array
constructors do not deopt.

R=ulan@chromium.org
BUG=363855
LOG=N

Review URL: https://codereview.chromium.org/247343002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@20887 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

include/v8.h

@@ -5533,7 +5533,7 @@ class Internals {
   static const int kJSObjectHeaderSize = 3 * kApiPointerSize;
   static const int kFixedArrayHeaderSize = 2 * kApiPointerSize;
   static const int kContextHeaderSize = 2 * kApiPointerSize;
-  static const int kContextEmbedderDataIndex = 65;
+  static const int kContextEmbedderDataIndex = 74;
   static const int kFullStringRepresentationMask = 0x07;
   static const int kStringEncodingMask = 0x4;
   static const int kExternalTwoByteRepresentationTag = 0x02;

src/bootstrapper.cc

@@ -207,8 +207,11 @@ class Genesis BASE_EMBEDDED {
                                           ElementsKind elements_kind);
   bool InstallNatives();
 
-  Handle<JSFunction> InstallTypedArray(const char* name,
-      ElementsKind elementsKind);
+  void InstallTypedArray(
+      const char* name,
+      ElementsKind elements_kind,
+      Handle<JSFunction>* fun,
+      Handle<Map>* external_map);
   bool InstallExperimentalNatives();
   void InstallBuiltinFunctionIds();
   void InstallJSFunctionResultCaches();
@@ -1039,9 +1042,14 @@ void Genesis::InitializeGlobal(Handle<GlobalObject> inner_global,
   { // -- T y p e d A r r a y s
 #define INSTALL_TYPED_ARRAY(Type, type, TYPE, ctype, size)                    \
     {                                                                         \
-      Handle<JSFunction> fun = InstallTypedArray(#Type "Array",               \
-          TYPE##_ELEMENTS);                                                   \
+      Handle<JSFunction> fun;                                                 \
+      Handle<Map> external_map;                                               \
+      InstallTypedArray(#Type "Array",                                        \
+          TYPE##_ELEMENTS,                                                    \
+          &fun,                                                               \
+          &external_map);                                                     \
       native_context()->set_##type##_array_fun(*fun);                         \
+      native_context()->set_##type##_array_external_map(*external_map);       \
     }
     TYPED_ARRAYS(INSTALL_TYPED_ARRAY)
 #undef INSTALL_TYPED_ARRAY
@@ -1252,18 +1260,26 @@ void Genesis::InitializeGlobal(Handle<GlobalObject> inner_global,
 }
 
 
-Handle<JSFunction> Genesis::InstallTypedArray(
-    const char* name, ElementsKind elementsKind) {
+void Genesis::InstallTypedArray(
+    const char* name,
+    ElementsKind elements_kind,
+    Handle<JSFunction>* fun,
+    Handle<Map>* external_map) {
   Handle<JSObject> global = Handle<JSObject>(native_context()->global_object());
   Handle<JSFunction> result = InstallFunction(global, name, JS_TYPED_ARRAY_TYPE,
       JSTypedArray::kSize, isolate()->initial_object_prototype(),
       Builtins::kIllegal, false, true);
 
   Handle<Map> initial_map = isolate()->factory()->NewMap(
-      JS_TYPED_ARRAY_TYPE, JSTypedArray::kSizeWithInternalFields, elementsKind);
+      JS_TYPED_ARRAY_TYPE,
+      JSTypedArray::kSizeWithInternalFields,
+      elements_kind);
   result->set_initial_map(*initial_map);
   initial_map->set_constructor(*result);
-  return result;
+  *fun = result;
+
+  ElementsKind external_kind = GetNextTransitionElementsKind(elements_kind);
+  *external_map = Map::AsElementsKind(initial_map, external_kind);
 }
 
 

src/contexts.h

@@ -134,6 +134,16 @@ enum BindingFlags {
   V(FLOAT32_ARRAY_FUN_INDEX, JSFunction, float32_array_fun) \
   V(FLOAT64_ARRAY_FUN_INDEX, JSFunction, float64_array_fun) \
   V(UINT8_CLAMPED_ARRAY_FUN_INDEX, JSFunction, uint8_clamped_array_fun) \
+  V(INT8_ARRAY_EXTERNAL_MAP_INDEX, Map, int8_array_external_map) \
+  V(UINT8_ARRAY_EXTERNAL_MAP_INDEX, Map, uint8_array_external_map) \
+  V(INT16_ARRAY_EXTERNAL_MAP_INDEX, Map, int16_array_external_map) \
+  V(UINT16_ARRAY_EXTERNAL_MAP_INDEX, Map, uint16_array_external_map) \
+  V(INT32_ARRAY_EXTERNAL_MAP_INDEX, Map, int32_array_external_map) \
+  V(UINT32_ARRAY_EXTERNAL_MAP_INDEX, Map, uint32_array_external_map) \
+  V(FLOAT32_ARRAY_EXTERNAL_MAP_INDEX, Map, float32_array_external_map) \
+  V(FLOAT64_ARRAY_EXTERNAL_MAP_INDEX, Map, float64_array_external_map) \
+  V(UINT8_CLAMPED_ARRAY_EXTERNAL_MAP_INDEX, Map, \
+      uint8_clamped_array_external_map) \
   V(DATA_VIEW_FUN_INDEX, JSFunction, data_view_fun) \
   V(SLOPPY_FUNCTION_MAP_INDEX, Map, sloppy_function_map) \
   V(STRICT_FUNCTION_MAP_INDEX, Map, strict_function_map) \
@@ -311,6 +321,15 @@ class Context: public FixedArray {
     FLOAT32_ARRAY_FUN_INDEX,
     FLOAT64_ARRAY_FUN_INDEX,
     UINT8_CLAMPED_ARRAY_FUN_INDEX,
+    INT8_ARRAY_EXTERNAL_MAP_INDEX,
+    UINT8_ARRAY_EXTERNAL_MAP_INDEX,
+    INT16_ARRAY_EXTERNAL_MAP_INDEX,
+    UINT16_ARRAY_EXTERNAL_MAP_INDEX,
+    INT32_ARRAY_EXTERNAL_MAP_INDEX,
+    UINT32_ARRAY_EXTERNAL_MAP_INDEX,
+    FLOAT32_ARRAY_EXTERNAL_MAP_INDEX,
+    FLOAT64_ARRAY_EXTERNAL_MAP_INDEX,
+    UINT8_CLAMPED_ARRAY_EXTERNAL_MAP_INDEX,
     DATA_VIEW_FUN_INDEX,
     MESSAGE_LISTENERS_INDEX,
     MAKE_MESSAGE_FUN_INDEX,