MapCache simplification. It is now a FixedArray that maps number of properties to a WeakCell with...

src/runtime/runtime-literals.cc

 // Copyright 2014 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.
 
 #include "src/v8.h"
 
 #include "src/allocation-site-scopes.h"
 #include "src/arguments.h"
 #include "src/ast.h"
 #include "src/parser.h"
 #include "src/runtime/runtime.h"
 #include "src/runtime/runtime-utils.h"
 
 namespace v8 {
 namespace internal {
 
 static Handle<Map> ComputeObjectLiteralMap(
     Handle<Context> context, Handle<FixedArray> constant_properties,
     bool* is_result_from_cache) {
-  Isolate* isolate = context->GetIsolate();
   int properties_length = constant_properties->length();
   int number_of_properties = properties_length / 2;
-  // Check that there are only internal strings and array indices among keys.
-  int number_of_string_keys = 0;
+
   for (int p = 0; p != properties_length; p += 2) {
     Object* key = constant_properties->get(p);
     uint32_t element_index = 0;
-    if (key->IsInternalizedString()) {
-      number_of_string_keys++;
-    } else if (key->ToArrayIndex(&element_index)) {
+    if (key->ToArrayIndex(&element_index)) {
       // An index key does not require space in the property backing store.
       number_of_properties--;
-    } else {
-      // Bail out as a non-internalized-string non-index key makes caching
-      // impossible.
-      // DCHECK to make sure that the if condition after the loop is false.
-      DCHECK(number_of_string_keys != number_of_properties);
-      break;
     }
   }
-  // If we only have internalized strings and array indices among keys then we
-  // can use the map cache in the native context.
-  const int kMaxKeys = 10;
-  if ((number_of_string_keys == number_of_properties) &&
-      (number_of_string_keys < kMaxKeys)) {
-    // Create the fixed array with the key.
-    Handle<FixedArray> keys =
-        isolate->factory()->NewFixedArray(number_of_string_keys);
-    if (number_of_string_keys > 0) {
-      int index = 0;
-      for (int p = 0; p < properties_length; p += 2) {
-        Object* key = constant_properties->get(p);
-        if (key->IsInternalizedString()) {
-          keys->set(index++, key);
-        }
-      }
-      DCHECK(index == number_of_string_keys);
-    }
-    *is_result_from_cache = true;
-    return isolate->factory()->ObjectLiteralMapFromCache(context, keys);
-  }
-  *is_result_from_cache = false;
-  return Map::Create(isolate, number_of_properties);
+  Isolate* isolate = context->GetIsolate();
+  return isolate->factory()->ObjectLiteralMapFromCache(
+      context, number_of_properties, is_result_from_cache);
 }
 
-
 MUST_USE_RESULT static MaybeHandle<Object> CreateLiteralBoilerplate(
     Isolate* isolate, Handle<FixedArray> literals,
     Handle<FixedArray> constant_properties);
 
 
 MUST_USE_RESULT static MaybeHandle<Object> CreateObjectLiteralBoilerplate(
     Isolate* isolate, Handle<FixedArray> literals,
     Handle<FixedArray> constant_properties, bool should_have_fast_elements,
     bool has_function_literal) {
   // Get the native context from the literals array.  This is the
@@ skipping 85 matching lines @@
 
   // Transform to fast properties if necessary. For object literals with
   // containing function literals we defer this operation until after all
   // computed properties have been assigned so that we can generate
   // constant function properties.
   if (should_transform && !has_function_literal) {
     JSObject::MigrateSlowToFast(boilerplate,
                                 boilerplate->map()->unused_property_fields(),
                                 "FastLiteral");
   }
-
   return boilerplate;
 }
 
 
 MaybeHandle<Object> Runtime::CreateArrayLiteralBoilerplate(
     Isolate* isolate, Handle<FixedArray> literals,
     Handle<FixedArray> elements) {
   // Create the JSArray.
   Handle<JSFunction> constructor(
       JSFunction::NativeContextFromLiterals(*literals)->array_function());
@@ skipping 275 matching lines @@
         JSObject::TransitionElementsKind(boilerplate_object, transitioned_kind);
       }
     }
     FixedArray* object_array = FixedArray::cast(object->elements());
     object_array->set(store_index, *value);
   }
   return *object;
 }
 }
 }  // namespace v8::internal