v8/test/mjsunit/regress/regress-4173.js
ishell@chromium.org 65f0e958f6 [runtime][tests] More *TypeFeedbackVector* -> *FeedbackVector* renamings.
BUG=

Change-Id: I859fef6b18e51cca80343a89e2b6f38eee95d408
Reviewed-on: https://chromium-review.googlesource.com/442428
Commit-Queue: Igor Sheludko <ishell@chromium.org>
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Cr-Commit-Position: refs/heads/master@{#43206}
2017-02-15 08:53:51 +00:00

59 lines
1.9 KiB
JavaScript

// Copyright 2015 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
function Migrator(o) {
return o.foo;
}
function Loader(o) {
return o[0];
}
var first_smi_array = [1];
var second_smi_array = [2];
var first_object_array = ["first"];
var second_object_array = ["string"];
assertTrue(%HasFastSmiElements(first_smi_array));
assertTrue(%HasFastSmiElements(second_smi_array));
assertTrue(%HasFastObjectElements(first_object_array));
assertTrue(%HasFastObjectElements(second_object_array));
// Prepare identical transition chains for smi and object arrays.
first_smi_array.foo = 0;
second_smi_array.foo = 0;
first_object_array.foo = 0;
second_object_array.foo = 0;
// Collect type feedback for not-yet-deprecated original object array map.
for (var i = 0; i < 3; i++) Migrator(second_object_array);
// Blaze a migration trail for smi array maps.
// This marks the migrated smi array map as a migration target.
first_smi_array.foo = 0.5;
print(second_smi_array.foo);
// Deprecate original object array map.
// Use TryMigrate from deferred optimized code to migrate second object array.
first_object_array.foo = 0.5;
%OptimizeFunctionOnNextCall(Migrator);
Migrator(second_object_array);
// |second_object_array| now erroneously has a smi map.
// Optimized code assuming smi elements will expose this.
for (var i = 0; i < 3; i++) Loader(second_smi_array);
%OptimizeFunctionOnNextCall(Loader);
assertEquals("string", Loader(second_object_array));
// Any of the following checks will also fail:
assertTrue(%HasFastObjectElements(second_object_array));
assertFalse(%HasFastSmiElements(second_object_array));
assertTrue(%HaveSameMap(first_object_array, second_object_array));
assertFalse(%HaveSameMap(first_smi_array, second_object_array));
%ClearFunctionFeedback(Loader);
%ClearFunctionFeedback(Migrator);