// Copyright 2016 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. // Flags: --allow-natives-syntax --noalways-opt var elements_kind = { fast_smi_only : 'fast smi only elements', fast : 'fast elements', fast_double : 'fast double elements', dictionary : 'dictionary elements', } function getKind(obj) { if (%HasSmiElements(obj)) return elements_kind.fast_smi_only; if (%HasObjectElements(obj)) return elements_kind.fast; if (%HasDoubleElements(obj)) return elements_kind.fast_double; if (%HasDictionaryElements(obj)) return elements_kind.dictionary; } function assertKind(expected, obj, name_opt) { assertEquals(expected, getKind(obj), name_opt); } (function() { function make1() { return new Array(); } function make2() { return new Array(); } function make3() { return new Array(); } function foo(a, i) { a[0] = i; } function run_test(maker_function) { var one = maker_function(); assertKind(elements_kind.fast_smi_only, one); // Use memento to pre-transition allocation site to DOUBLE elements. foo(one, 1.5); // Newly created arrays should now have DOUBLE elements right away. var two = maker_function(); assertKind(elements_kind.fast_double, two); } // Initialize the KeyedStoreIC in foo; the actual operation will be done // in the runtime. run_test(make1); // Run again; the IC optimistically assumed to only see the transitioned // (double-elements) map again, so this will make it polymorphic. // The actual operation will again be done in the runtime. run_test(make2); // Finally, check if the initialized IC honors the allocation memento. run_test(make3); })();