src/third_party/v8/test/mjsunit/compiler/deopt-tonumber-binop.js

// Copyright 2015 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// Flags: --allow-natives-syntax
//
var f = (function() {
  "use asm";
  function f(x, y) {
    return x - y;
  }
  return f;
})();

var counter = 0;

var deopt = { toString : function() {
  %DeoptimizeFunction(f);
  counter++;
  return "2";
} };

var o = { toString : function() {
  counter++;
  return "1";
} };

%PrepareFunctionForOptimization(f);
counter = 0;
assertEquals(1, f(deopt, o));
assertEquals(2, counter);

%OptimizeFunctionOnNextCall(f);
counter = 0;
assertEquals(-1, f(o, deopt));
assertEquals(2, counter);

%PrepareFunctionForOptimization(f);
%OptimizeFunctionOnNextCall(f);
counter = 0;
assertEquals(0, f(deopt, deopt));
assertEquals(2, counter);