tor-browser

The Tor Browser
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recover-lambdas.js (1662B)


      1 // |jit-test| --no-ion; --ion-osr=off
      2 // Warp lacks Scalar Replacement support (bug 1650233). Re-evaluate after that
      3 // bug has been fixed.
      4 
      5 var max = 40;
      6 setJitCompilerOption("ion.warmup.trigger", max - 10);
      7 
      8 // Prevent the GC from cancelling Ion compilations, when we expect them to succeed
      9 gczeal(0);
     10 
     11 // This function is used to escape "g" which is a non-escaped inner function.
     12 // As it is not escaped within "f", the lambda for "g" would be computed on the
     13 // bailout path. Resolving the first ".caller" implies that we have to recover
     14 // the lambda. Resolving the second ".caller" is needed such as we can build the
     15 // test case without explicitly escaping "g", which would prevent this
     16 // optimization.
     17 
     18 function return_f(i) {
     19  if (i != max - 1)
     20    return f;
     21 
     22  // return_f.caller == g
     23  // return_f.caller.caller == f
     24  return return_f.caller.caller;
     25 }
     26 
     27 function f(i) {
     28  function g() {
     29    return return_f(i);
     30  }
     31 
     32  assertRecoveredOnBailout(g, true);
     33  return g();
     34 }
     35 
     36 // This function is used to cause an invalidation after having removed a branch.
     37 // These functions are used to check if we correctly recover the lambda
     38 // and its environment during a bailout.
     39 var uceFault = function (i) {
     40    if (i == max - 1)
     41        uceFault = function (i) { return true; };
     42    return false;
     43 };
     44 
     45 var uceFault_lambdaCall = eval(`(${uceFault})`.replace('uceFault', 'uceFault_lambdaCall'));
     46 function lambdaCall(i) {
     47    function g() {
     48        return i;
     49    }
     50 
     51    if (uceFault_lambdaCall(i) || uceFault_lambdaCall(i))
     52        assertEq(g(), i);
     53 
     54    assertRecoveredOnBailout(g, true);
     55 };
     56 
     57 
     58 
     59 for (var i = 0; i < max; i++) {
     60  assertEq(f(i), f);
     61  lambdaCall(i);
     62 }