spreadcall-not-optimized-dynamic-4b.js (1143B)
1 // Tests when JSOP_OPTIMIZE_SPREADCALL no longer apply after the initial Ion 2 // 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 // The rest argument's prototype isn't Array.prototype. 18 function test() { 19 class MyArray extends Array { } 20 function maybeInvalidate(rest) { 21 // Use a WithStatement to prevent Ion-inlining. This ensures any 22 // bailouts due to type changes don't occur in this function, but 23 // instead in the caller. 24 with ({}); 25 26 if (i >= 1900) { 27 rest = new MyArray(3, 4); 28 } 29 return rest; 30 } 31 function fn(...rest) { 32 rest = maybeInvalidate(rest); 33 return add(...rest); 34 } 35 for (var i = 0; i < 4000; ++i) { 36 assertEq(fn(1, 2), i < 1900 ? 3 : 7); 37 } 38 } 39 test();