[contexts] Place the initial JSArray maps on the native context directly.

src/contexts.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_CONTEXTS_H_
 #define V8_CONTEXTS_H_
 
 #include "src/heap/heap.h"
 #include "src/objects.h"
 
@@ skipping 183 matching lines @@
   V(INITIAL_ARRAY_PROTOTYPE_INDEX, JSObject, initial_array_prototype)          \
   V(INITIAL_OBJECT_PROTOTYPE_INDEX, JSObject, initial_object_prototype)        \
   V(INT16_ARRAY_FUN_INDEX, JSFunction, int16_array_fun)                        \
   V(INT16X8_FUNCTION_INDEX, JSFunction, int16x8_function)                      \
   V(INT32_ARRAY_FUN_INDEX, JSFunction, int32_array_fun)                        \
   V(INT32X4_FUNCTION_INDEX, JSFunction, int32x4_function)                      \
   V(INT8_ARRAY_FUN_INDEX, JSFunction, int8_array_fun)                          \
   V(INT8X16_FUNCTION_INDEX, JSFunction, int8x16_function)                      \
   V(INTERNAL_ARRAY_FUNCTION_INDEX, JSFunction, internal_array_function)        \
   V(ITERATOR_RESULT_MAP_INDEX, Map, iterator_result_map)                       \
-  V(JS_ARRAY_MAPS_INDEX, Object, js_array_maps)                                \
-  V(JS_ARRAY_STRONG_MAPS_INDEX, Object, js_array_strong_maps)                  \
+  V(JS_ARRAY_FAST_SMI_ELEMENTS_MAP_INDEX, Map,                                 \
+    js_array_fast_smi_elements_map_index)                                      \
+  V(JS_ARRAY_FAST_HOLEY_SMI_ELEMENTS_MAP_INDEX, Map,                           \
+    js_array_fast_holey_smi_elements_map_index)                                \
+  V(JS_ARRAY_FAST_ELEMENTS_MAP_INDEX, Map, js_array_fast_elements_map_index)   \
+  V(JS_ARRAY_FAST_HOLEY_ELEMENTS_MAP_INDEX, Map,                               \
+    js_array_fast_holey_elements_map_index)                                    \
+  V(JS_ARRAY_FAST_DOUBLE_ELEMENTS_MAP_INDEX, Map,                              \
+    js_array_fast_double_elements_map_index)                                   \
+  V(JS_ARRAY_FAST_HOLEY_DOUBLE_ELEMENTS_MAP_INDEX, Map,                        \
+    js_array_fast_holey_double_elements_map_index)                             \
+  V(JS_ARRAY_FAST_SMI_ELEMENTS_STRONG_MAP_INDEX, Map,                          \
+    js_array_fast_smi_elements_strong_map_index)                               \
+  V(JS_ARRAY_FAST_HOLEY_SMI_ELEMENTS_STRONG_MAP_INDEX, Map,                    \
+    js_array_fast_holey_smi_elements_strong_map_index)                         \
+  V(JS_ARRAY_FAST_ELEMENTS_STRONG_MAP_INDEX, Map,                              \
+    js_array_fast_elements_strong_map_index)                                   \
+  V(JS_ARRAY_FAST_HOLEY_ELEMENTS_STRONG_MAP_INDEX, Map,                        \
+    js_array_fast_holey_elements_strong_map_index)                             \
+  V(JS_ARRAY_FAST_DOUBLE_ELEMENTS_STRONG_MAP_INDEX, Map,                       \
+    js_array_fast_double_elements_strong_map_index)                            \
+  V(JS_ARRAY_FAST_HOLEY_DOUBLE_ELEMENTS_STRONG_MAP_INDEX, Map,                 \
+    js_array_fast_holey_double_elements_strong_map_index)                      \
   V(JS_MAP_FUN_INDEX, JSFunction, js_map_fun)                                  \
   V(JS_MAP_MAP_INDEX, Map, js_map_map)                                         \
   V(JS_OBJECT_STRONG_MAP_INDEX, Map, js_object_strong_map)                     \
   V(JS_SET_FUN_INDEX, JSFunction, js_set_fun)                                  \
   V(JS_SET_MAP_INDEX, Map, js_set_map)                                         \
   V(JS_WEAK_MAP_FUN_INDEX, JSFunction, js_weak_map_fun)                        \
   V(JS_WEAK_SET_FUN_INDEX, JSFunction, js_weak_set_fun)                        \
   V(MAP_CACHE_INDEX, Object, map_cache)                                        \
   V(MAP_ITERATOR_MAP_INDEX, Map, map_iterator_map)                             \
   V(STRING_ITERATOR_MAP_INDEX, Map, string_iterator_map)                       \
@@ skipping 171 matching lines @@
     // Properties from here are treated as weak references by the full GC.
     // Scavenge treats them as strong references.
     OPTIMIZED_FUNCTIONS_LIST,  // Weak.
     OPTIMIZED_CODE_LIST,       // Weak.
     DEOPTIMIZED_CODE_LIST,     // Weak.
     NEXT_CONTEXT_LINK,         // Weak.
 
     // Total number of slots.
     NATIVE_CONTEXT_SLOTS,
     FIRST_WEAK_SLOT = OPTIMIZED_FUNCTIONS_LIST,
+    FIRST_JS_ARRAY_MAP_SLOT = JS_ARRAY_FAST_SMI_ELEMENTS_MAP_INDEX,
+    FIRST_JS_ARRAY_STRONG_MAP_SLOT =
+        JS_ARRAY_FAST_SMI_ELEMENTS_STRONG_MAP_INDEX,
 
     MIN_CONTEXT_SLOTS = GLOBAL_PROXY_INDEX,
     // This slot holds the thrown value in catch contexts.
     THROWN_OBJECT_INDEX = MIN_CONTEXT_SLOTS,
   };
 
   void IncrementErrorsThrown();
   int GetErrorsThrown();
 
   // Direct slot access.
@@ skipping 124 matching lines @@
       return is_strong(language_mode)
                  ? STRONG_FUNCTION_MAP_INDEX
                  : STRICT_FUNCTION_WITHOUT_PROTOTYPE_MAP_INDEX;
     }
 
     return is_strong(language_mode) ? STRONG_FUNCTION_MAP_INDEX :
            is_strict(language_mode) ? STRICT_FUNCTION_MAP_INDEX
                                     : SLOPPY_FUNCTION_MAP_INDEX;
   }
 
+  static int ArrayMapIndex(ElementsKind elements_kind,
+                           Strength strength = Strength::WEAK) {
+    DCHECK(IsFastElementsKind(elements_kind));
+    return elements_kind + (is_strong(strength) ? FIRST_JS_ARRAY_STRONG_MAP_SLOT
+                                                : FIRST_JS_ARRAY_MAP_SLOT);
+  }
+
   static const int kSize = kHeaderSize + NATIVE_CONTEXT_SLOTS * kPointerSize;
   static const int kNotFound = -1;
 
   // GC support.
   typedef FixedBodyDescriptor<
       kHeaderSize, kSize, kSize> ScavengeBodyDescriptor;
 
   typedef FixedBodyDescriptor<
       kHeaderSize,
       kHeaderSize + FIRST_WEAK_SLOT * kPointerSize,
       kSize> MarkCompactBodyDescriptor;
 
  private:
 #ifdef DEBUG
   // Bootstrapping-aware type checks.
   static bool IsBootstrappingOrNativeContext(Isolate* isolate, Object* object);
   static bool IsBootstrappingOrValidParentContext(Object* object, Context* kid);
 #endif
 
   STATIC_ASSERT(kHeaderSize == Internals::kContextHeaderSize);
   STATIC_ASSERT(EMBEDDER_DATA_INDEX == Internals::kContextEmbedderDataIndex);
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_CONTEXTS_H_