Optimize testing for an index's existence in packed Arrays

src/macros.py

 # Copyright 2006-2009 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 150 matching lines @@
 macro TO_INTEGER_FOR_SIDE_EFFECT(arg) = (%_IsSmi(%IS_VAR(arg)) ? arg : ToNumber(arg));
 macro TO_INTEGER_MAP_MINUS_ZERO(arg) = (%_IsSmi(%IS_VAR(arg)) ? arg : %NumberToIntegerMapMinusZero(ToNumber(arg)));
 macro TO_INT32(arg) = (%_IsSmi(%IS_VAR(arg)) ? arg : (arg >> 0));
 macro TO_UINT32(arg) = (arg >>> 0);
 macro TO_STRING_INLINE(arg) = (IS_STRING(%IS_VAR(arg)) ? arg : NonStringToString(arg));
 macro TO_NUMBER_INLINE(arg) = (IS_NUMBER(%IS_VAR(arg)) ? arg : NonNumberToNumber(arg));
 macro TO_OBJECT_INLINE(arg) = (IS_SPEC_OBJECT(%IS_VAR(arg)) ? arg : ToObject(arg));
 macro JSON_NUMBER_TO_STRING(arg) = ((%_IsSmi(%IS_VAR(arg)) || arg - arg == 0) ? %_NumberToString(arg) : "null");
 macro HAS_OWN_PROPERTY(obj, index) = (%_CallFunction(obj, index, ObjectHasOwnProperty));
 macro SHOULD_CREATE_WRAPPER(functionName, receiver) = (!IS_SPEC_OBJECT(receiver) && %IsSloppyModeFunction(functionName));
+macro HAS_INDEX(array, index, is_array) = ((is_array && %_HasFastPackedElements(%IS_VAR(array))) ? (index < array.length) : (index in array));
 
 # Private names.
 # GET_PRIVATE should only be used if the property is known to exists on obj
 # itself (it should really use %GetOwnProperty, but that would be way slower).
 macro GLOBAL_PRIVATE(name) = (%CreateGlobalPrivateOwnSymbol(name));
 macro NEW_PRIVATE_OWN(name) = (%CreatePrivateOwnSymbol(name));
 macro IS_PRIVATE(sym) = (%SymbolIsPrivate(sym));
 macro HAS_PRIVATE(obj, sym) = (%HasOwnProperty(obj, sym));
 macro HAS_DEFINED_PRIVATE(obj, sym) = (!IS_UNDEFINED(obj[sym]));
 macro GET_PRIVATE(obj, sym) = (obj[sym]);
@@ skipping 105 matching lines @@
 
 # Use for keys, values and entries iterators.
 const ITERATOR_KIND_KEYS = 1;
 const ITERATOR_KIND_VALUES = 2;
 const ITERATOR_KIND_ENTRIES = 3;
 
 # Check whether debug is active.
 const DEBUG_IS_ACTIVE = (%_DebugIsActive() != 0);
 macro DEBUG_IS_STEPPING(function) = (%_DebugIsActive() != 0 && %DebugCallbackSupportsStepping(function));
 macro DEBUG_PREPARE_STEP_IN_IF_STEPPING(function) = if (DEBUG_IS_STEPPING(function)) %DebugPrepareStepInIfStepping(function);