v8/test/mjsunit/compiler/phi-representations.js

// Copyright 2013 the V8 project authors. All rights reserved.
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// modification, are permitted provided that the following conditions are
// met:
//
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// Flags: --allow-natives-syntax

function ar() {
  var r = undefined;
  var f = 1;
  while (f--) {
    r = (typeof r === 'undefined') ? 0.1 : r;
  };
  return (r - r);
}

%PrepareFunctionForOptimization(ar);
assertEquals(0, ar());
assertEquals(0, ar());
%OptimizeFunctionOnNextCall(ar);
assertEquals(0, ar());

function ar2() {
  var r = undefined;
  var f = 1;
  while (f--) {
    r = r === undefined ? 0.1 : r;
  };
  return (r - r);
}

%PrepareFunctionForOptimization(ar2);
assertEquals(0, ar2());
assertEquals(0, ar2());
%OptimizeFunctionOnNextCall(ar2);
assertEquals(0, ar2());