17a74ddd3d
PR-URL: https://github.com/nodejs/node/pull/49639 Reviewed-By: Jiawen Geng <technicalcute@gmail.com> Reviewed-By: Rafael Gonzaga <rafael.nunu@hotmail.com> Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>
56 lines
1.4 KiB
JavaScript
56 lines
1.4 KiB
JavaScript
// Copyright 2023 the V8 project authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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//
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// Flags: --allow-natives-syntax --maglev --no-always-turbofan
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function A() { this.x = 1 }
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function B() { this.x = 1 }
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const a = new A();
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a.y = 1;
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(new A()).x = 0.1; // deprecate a
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const b = new B();
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b.y = 1;
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(new B()).x = 0.1; // deprecate b
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function load(o) { return o.y }
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// Make o.y polymorphic and compile it with maglev. a and b will be deprecated
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// causing migrations in a way that o.y is still at the same offset. This allows
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// maglev to optimize it behind a CheckMapsWithMigration() node.
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// | a | | | a |
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// |--------| | |-----------|
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// | x: Smi | | | x: Double |
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// |
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// | -|-> |
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// V -|-> V
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// |
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// | a | | | a |
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// |--------| | |-----------|
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// | x: Smi | | | x: Double |
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// | y: Smi | | | y: Smi | <-- y did not change.
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%PrepareFunctionForOptimization(load);
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load(a);
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load(b);
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%OptimizeMaglevOnNextCall(load);
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load(a);
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load(b);
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assertOptimized(load);
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// Create a fresh deprecated map, to test the migration path in
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// CheckMapsWithMigration().
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function C() { this.x = 1 }
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const c = new C();
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c.y = 1;
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(new C()).x = 0.1; // deprecate c
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load(c);
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assertUnoptimized(load);
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