tor-browser

The Tor Browser
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spreadcall-not-optimized-static-6b.js (1061B)


      1 // Tests when JSOP_OPTIMIZE_SPREADCALL can't be applied during the initial
      2 // Ion compilation.
      3 
      4 // JSOP_OPTIMIZE_SPREADCALL can be optimised when the following conditions
      5 // are fulfilled:
      6 //   (1) the argument is an array
      7 //   (2) the array has no hole
      8 //   (3) array[@@iterator] is not modified
      9 //   (4) the array's prototype is Array.prototype
     10 //   (5) Array.prototype[@@iterator] is not modified
     11 //   (6) %ArrayIteratorPrototype%.next is not modified
     12 
     13 function add(a, b) {
     14    return a + b;
     15 }
     16 
     17 // %ArrayIteratorPrototype%.next was modified.
     18 function test() {
     19    var ArrayIteratorPrototype = Object.getPrototypeOf(Array.prototype[Symbol.iterator]());
     20    var ArrayIteratorPrototypeNext = ArrayIteratorPrototype.next;
     21    ArrayIteratorPrototype.next = function() {
     22        var res = ArrayIteratorPrototypeNext.call(this);
     23        if (!res.done) {
     24            res.value += 2;
     25        }
     26        return res;
     27    };
     28    function fn(...rest) {
     29        return add(...rest);
     30    }
     31    for (var i = 0; i < 2000; ++i) {
     32        assertEq(fn(1, 2), 7);
     33    }
     34 }
     35 test();