JSTests/stress/bigint64-atomics.js

function shouldBe(actual, expected) {
    if (actual !== expected)
        throw new Error('bad value: ' + actual);
}

var array = new BigInt64Array(new SharedArrayBuffer(8 * 8));
shouldBe(array.length, 8);

function test(array) {
    shouldBe(Atomics.add(array, 0, 8n), 0n);
    shouldBe(array[0], 8n);
    shouldBe(Atomics.sub(array, 0, 1n), 8n);
    shouldBe(array[0], 7n);
    shouldBe(Atomics.and(array, 0, 0b11110n), 7n);
    shouldBe(array[0], 6n);
    shouldBe(Atomics.compareExchange(array, 0, 5n, 0n), 6n);
    shouldBe(array[0], 6n);
    shouldBe(Atomics.compareExchange(array, 0, 6n, 1n), 6n);
    shouldBe(array[0], 1n);
    shouldBe(Atomics.exchange(array, 0, 2n), 1n);
    shouldBe(array[0], 2n);
    shouldBe(Atomics.load(array, 0), 2n);
    shouldBe(Atomics.or(array, 0, 1n), 2n);
    shouldBe(array[0], 3n);
    shouldBe(Atomics.store(array, 0, 6n), 6n);
    shouldBe(array[0], 6n);
    shouldBe(Atomics.xor(array, 0, 0b11111n), 6n);
    shouldBe(array[0], 25n);
    shouldBe(Atomics.store(array, 0, 0n), 0n);
}
noInline(array);

for (var i = 0; i < 1e4; ++i)
    test(array);