spreadcall-not-optimized-dynamic-1.js (1212B)
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 is overwritten with a non-Array object. 18 function test() { 19 var badRest = { 20 *[Symbol.iterator]() { 21 yield 3; 22 yield 4; 23 } 24 }; 25 function maybeInvalidate(rest) { 26 // Use a WithStatement to prevent Ion-inlining. This ensures any 27 // bailouts due to type changes don't occur in this function, but 28 // instead in the caller. 29 with ({}); 30 31 if (i >= 1900) { 32 return badRest; 33 } 34 return rest; 35 } 36 function fn(...rest) { 37 rest = maybeInvalidate(rest); 38 return add(...rest); 39 } 40 for (var i = 0; i < 4000; ++i) { 41 assertEq(fn(1, 2), i < 1900 ? 3 : 7); 42 } 43 } 44 test();