// Copyright 2024 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: --const-tracking-let --allow-natives-syntax // Flags: --turbofan --no-always-turbofan --maglev --no-stress-maglev // Flags: --sparkplug --no-always-sparkplug let a = 1; function read() { return a; } // In this variant, `read` is optimized before `write`. %PrepareFunctionForOptimization(read); assertEquals(1, read()); %OptimizeFunctionOnNextCall(read); assertEquals(1, read()); assertOptimized(read); function write(newA) { a = newA; } %PrepareFunctionForOptimization(write); // Write the same value. This won't invalidate the constness. write(1); assertOptimized(read); %OptimizeFunctionOnNextCall(write); write(1); // TODO(v8:13567): The above will deopt `write` immediately, since we don't have // the "if the value is the same, don't deopt" check yet. // assertOptimized(write); assertOptimized(read); // This invalidates the constness which deopts `read`. write(2); assertUnoptimized(write); assertUnoptimized(read); assertEquals(2, read());