Optimize loads from root-array in X64.

src/heap.h

 // Copyright 2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 31 matching lines @@
 
 // Defines all the roots in Heap.
 #define UNCONDITIONAL_STRONG_ROOT_LIST(V)                                      \
   /* Put the byte array map early.  We need it to be in place by the time   */ \
   /* the deserializer hits the next page, since it wants to put a byte      */ \
   /* array in the unused space at the end of the page.                      */ \
   V(Map, byte_array_map, ByteArrayMap)                                         \
   V(Map, one_pointer_filler_map, OnePointerFillerMap)                          \
   V(Map, two_pointer_filler_map, TwoPointerFillerMap)                          \
   /* Cluster the most popular ones in a few cache lines here at the top.    */ \
-  V(Smi, stack_limit, StackLimit)                                              \
   V(Object, undefined_value, UndefinedValue)                                   \
   V(Object, the_hole_value, TheHoleValue)                                      \
   V(Object, null_value, NullValue)                                             \
   V(Object, true_value, TrueValue)                                             \
   V(Object, false_value, FalseValue)                                           \
   V(Object, arguments_marker, ArgumentsMarker)                                 \
   V(Map, heap_number_map, HeapNumberMap)                                       \
   V(Map, global_context_map, GlobalContextMap)                                 \
   V(Map, fixed_array_map, FixedArrayMap)                                       \
   V(Map, fixed_cow_array_map, FixedCOWArrayMap)                                \
   V(Object, no_interceptor_result_sentinel, NoInterceptorResultSentinel)       \
   V(Map, meta_map, MetaMap)                                                    \
+  V(Map, hash_table_map, HashTableMap)                                         \
+  V(Smi, stack_limit, StackLimit)                                              \
+  V(FixedArray, number_string_cache, NumberStringCache)                        \
+  V(Object, instanceof_cache_function, InstanceofCacheFunction)                \
+  V(Object, instanceof_cache_map, InstanceofCacheMap)                          \
+  V(Object, instanceof_cache_answer, InstanceofCacheAnswer)                    \
+  V(FixedArray, single_character_string_cache, SingleCharacterStringCache)     \
   V(Object, termination_exception, TerminationException)                       \
-  V(Map, hash_table_map, HashTableMap)                                         \
   V(FixedArray, empty_fixed_array, EmptyFixedArray)                            \
   V(ByteArray, empty_byte_array, EmptyByteArray)                               \
+  V(String, empty_string, EmptyString)                                         \
+  V(DescriptorArray, empty_descriptor_array, EmptyDescriptorArray)             \
   V(Map, string_map, StringMap)                                                \
   V(Map, ascii_string_map, AsciiStringMap)                                     \
   V(Map, symbol_map, SymbolMap)                                                \
+  V(Map, cons_string_map, ConsStringMap)                                       \
+  V(Map, cons_ascii_string_map, ConsAsciiStringMap)                            \
   V(Map, ascii_symbol_map, AsciiSymbolMap)                                     \
   V(Map, cons_symbol_map, ConsSymbolMap)                                       \
   V(Map, cons_ascii_symbol_map, ConsAsciiSymbolMap)                            \
   V(Map, external_symbol_map, ExternalSymbolMap)                               \
   V(Map, external_symbol_with_ascii_data_map, ExternalSymbolWithAsciiDataMap)  \
   V(Map, external_ascii_symbol_map, ExternalAsciiSymbolMap)                    \
-  V(Map, cons_string_map, ConsStringMap)                                       \
-  V(Map, cons_ascii_string_map, ConsAsciiStringMap)                            \
   V(Map, external_string_map, ExternalStringMap)                               \
   V(Map, external_string_with_ascii_data_map, ExternalStringWithAsciiDataMap)  \
   V(Map, external_ascii_string_map, ExternalAsciiStringMap)                    \
   V(Map, undetectable_string_map, UndetectableStringMap)                       \
   V(Map, undetectable_ascii_string_map, UndetectableAsciiStringMap)            \
   V(Map, pixel_array_map, PixelArrayMap)                                       \
   V(Map, external_byte_array_map, ExternalByteArrayMap)                        \
   V(Map, external_unsigned_byte_array_map, ExternalUnsignedByteArrayMap)       \
   V(Map, external_short_array_map, ExternalShortArrayMap)                      \
   V(Map, external_unsigned_short_array_map, ExternalUnsignedShortArrayMap)     \
   V(Map, external_int_array_map, ExternalIntArrayMap)                          \
   V(Map, external_unsigned_int_array_map, ExternalUnsignedIntArrayMap)         \
   V(Map, external_float_array_map, ExternalFloatArrayMap)                      \
   V(Map, context_map, ContextMap)                                              \
   V(Map, catch_context_map, CatchContextMap)                                   \
   V(Map, code_map, CodeMap)                                                    \
   V(Map, oddball_map, OddballMap)                                              \
   V(Map, global_property_cell_map, GlobalPropertyCellMap)                      \
   V(Map, shared_function_info_map, SharedFunctionInfoMap)                      \
   V(Map, message_object_map, JSMessageObjectMap)                               \
   V(Map, proxy_map, ProxyMap)                                                  \
   V(Object, nan_value, NanValue)                                               \
   V(Object, minus_zero_value, MinusZeroValue)                                  \
-  V(Object, instanceof_cache_function, InstanceofCacheFunction)                \
-  V(Object, instanceof_cache_map, InstanceofCacheMap)                          \
-  V(Object, instanceof_cache_answer, InstanceofCacheAnswer)                    \
-  V(String, empty_string, EmptyString)                                         \
-  V(DescriptorArray, empty_descriptor_array, EmptyDescriptorArray)             \
   V(Map, neander_map, NeanderMap)                                              \
   V(JSObject, message_listeners, MessageListeners)                             \
   V(Proxy, prototype_accessors, PrototypeAccessors)                            \
   V(NumberDictionary, code_stubs, CodeStubs)                                   \
   V(NumberDictionary, non_monomorphic_cache, NonMonomorphicCache)              \
   V(Code, js_entry_code, JsEntryCode)                                          \
   V(Code, js_construct_entry_code, JsConstructEntryCode)                       \
   V(Code, c_entry_code, CEntryCode)                                            \
-  V(FixedArray, number_string_cache, NumberStringCache)                        \
-  V(FixedArray, single_character_string_cache, SingleCharacterStringCache)     \
   V(FixedArray, natives_source_cache, NativesSourceCache)                      \
   V(Object, last_script_id, LastScriptId)                                      \
   V(Script, empty_script, EmptyScript)                                         \
   V(Smi, real_stack_limit, RealStackLimit)                                     \
   V(StringDictionary, intrinsic_function_names, IntrinsicFunctionNames)        \
 
 #if V8_TARGET_ARCH_ARM && !V8_INTERPRETED_REGEXP
 #define STRONG_ROOT_LIST(V)                                                    \
   UNCONDITIONAL_STRONG_ROOT_LIST(V)                                            \
   V(Code, re_c_entry_code, RegExpCEntryCode)                                   \
@@ skipping 83 matching lines @@
   V(space_symbol, " ")                                                   \
   V(exec_symbol, "exec")                                                 \
   V(zero_symbol, "0")                                                    \
   V(global_eval_symbol, "GlobalEval")                                    \
   V(identity_hash_symbol, "v8::IdentityHash")                            \
   V(closure_symbol, "(closure)")                                         \
   V(use_strict, "use strict")                                            \
   V(KeyedLoadExternalArray_symbol, "KeyedLoadExternalArray")             \
   V(KeyedStoreExternalArray_symbol, "KeyedStoreExternalArray")
 
-
 // Forward declarations.
 class GCTracer;
 class HeapStats;
 class WeakObjectRetainer;
 
 
 typedef String* (*ExternalStringTableUpdaterCallback)(Object** pointer);
 
 typedef bool (*DirtyRegionCallback)(Address start,
                                     Address end,
@@ skipping 1977 matching lines @@
   AssertNoAllocation no_alloc;  // i.e. no gc allowed.
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(PathTracer);
 };
 #endif  // DEBUG || LIVE_OBJECT_LIST
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_H_