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 // Copyright 2008 the V8 project authors. All rights reserved.

 // Redistribution and use in source and binary forms, with or without

 // modification, are permitted provided that the following conditions are

 // met:

 //

 //     * Redistributions of source code must retain the above copyright

 //       notice, this list of conditions and the following disclaimer.

 //     * Redistributions in binary form must reproduce the above

 //       copyright notice, this list of conditions and the following

 //       disclaimer in the documentation and/or other materials provided

 //       with the distribution.

 //     * Neither the name of Google Inc. nor the names of its

 //       contributors may be used to endorse or promote products derived

 //       from this software without specific prior written permission.

 //

 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 // Simple framework for running the benchmark suites and

 // computing a score based on the timing measurements.

 // A benchmark has a name (string) and a function that will be run to

 // do the performance measurement. The optional setup and tearDown

 // arguments are functions that will be invoked before and after

 // running the benchmark, but the running time of these functions will

 // not be accounted for in the benchmark score.

 function Benchmark(name, run, setup, tearDown) {

   this.name = name;

   this.run = run;

   this.Setup = setup ? setup : function() { };

   this.TearDown = tearDown ? tearDown : function() { };

 }

 // Benchmark results hold the benchmark and the measured time used to

 // run the benchmark. The benchmark score is computed later once a

 // full benchmark suite has run to completion.

 function BenchmarkResult(benchmark, time) {

   this.benchmark = benchmark;

   this.time = time;

 }

 // Automatically convert results to numbers. Used by the geometric

 // mean computation.

 BenchmarkResult.prototype.valueOf = function() {

   return this.time;

 }

 // Suites of benchmarks consist of a name and the set of benchmarks in

 // addition to the reference timing that the final score will be based

 // on. This way, all scores are relative to a reference run and higher

 // scores implies better performance.

 function BenchmarkSuite(name, reference, benchmarks) {

   this.name = name;

   this.reference = reference;

   this.benchmarks = benchmarks;

   BenchmarkSuite.suites.push(this);

 }

 // Keep track of all declared benchmark suites.

 BenchmarkSuite.suites = [];

 // Scores are not comparable across versions. Bump the version if

 // you're making changes that will affect that scores, e.g. if you add

 // a new benchmark or change an existing one.

 BenchmarkSuite.version = '5';

 // To make the benchmark results predictable, we replace Math.random

 // with a 100% deterministic alternative.

 Math.random = (function() {

   var seed = 49734321;

   return function() {

     // Robert Jenkins' 32 bit integer hash function.

     seed = ((seed + 0x7ed55d16) + (seed << 12))  & 0xffffffff;

     seed = ((seed ^ 0xc761c23c) ^ (seed >>> 19)) & 0xffffffff;

     seed = ((seed + 0x165667b1) + (seed << 5))   & 0xffffffff;

     seed = ((seed + 0xd3a2646c) ^ (seed << 9))   & 0xffffffff;

     seed = ((seed + 0xfd7046c5) + (seed << 3))   & 0xffffffff;

     seed = ((seed ^ 0xb55a4f09) ^ (seed >>> 16)) & 0xffffffff;

     return (seed & 0xfffffff) / 0x10000000;

   };

 })();

 // Runs all registered benchmark suites and optionally yields between

 // each individual benchmark to avoid running for too long in the

 // context of browsers. Once done, the final score is reported to the

 // runner.

 BenchmarkSuite.RunSuites = function(runner) {

   var continuation = null;

   var suites = BenchmarkSuite.suites;

   var length = suites.length;

   BenchmarkSuite.scores = [];

   var index = 0;

   function RunStep() {

     while (continuation || index < length) {

       if (continuation) {

         continuation = continuation();

       } else {

         var suite = suites[index++];

         if (runner.NotifyStart) runner.NotifyStart(suite.name);

         continuation = suite.RunStep(runner);

       }

       if (continuation && typeof window != 'undefined' && window.setTimeout) {

         window.setTimeout(RunStep, 25);

         return;

       }

     }

     if (runner.NotifyScore) {

       var score = BenchmarkSuite.GeometricMean(BenchmarkSuite.scores);

       var formatted = BenchmarkSuite.FormatScore(100 * score);

       runner.NotifyScore(formatted);

     }

   }

   RunStep();

 }

 // Counts the total number of registered benchmarks. Useful for

 // showing progress as a percentage.

 BenchmarkSuite.CountBenchmarks = function() {

   var result = 0;

   var suites = BenchmarkSuite.suites;

   for (var i = 0; i < suites.length; i++) {

     result += suites[i].benchmarks.length;

   }

   return result;

 }

 // Computes the geometric mean of a set of numbers.

 BenchmarkSuite.GeometricMean = function(numbers) {

   var log = 0;

   for (var i = 0; i < numbers.length; i++) {

     log += Math.log(numbers[i]);

   }

   return Math.pow(Math.E, log / numbers.length);

 }

 // Converts a score value to a string with at least three significant

 // digits.

 BenchmarkSuite.FormatScore = function(value) {

   if (value > 100) {

     return value.toFixed(0);

   } else {

     return value.toPrecision(3);

   }

 }

 // Notifies the runner that we're done running a single benchmark in

 // the benchmark suite. This can be useful to report progress.

 BenchmarkSuite.prototype.NotifyStep = function(result) {

   this.results.push(result);

   if (this.runner.NotifyStep) this.runner.NotifyStep(result.benchmark.name);

 }

 // Notifies the runner that we're done with running a suite and that

 // we have a result which can be reported to the user if needed.

 BenchmarkSuite.prototype.NotifyResult = function() {

   var mean = BenchmarkSuite.GeometricMean(this.results);

   var score = this.reference / mean;

   BenchmarkSuite.scores.push(score);

   if (this.runner.NotifyResult) {

     var formatted = BenchmarkSuite.FormatScore(100 * score);

     this.runner.NotifyResult(this.name, formatted);

   }

 }

 // Notifies the runner that running a benchmark resulted in an error.

 BenchmarkSuite.prototype.NotifyError = function(error) {

   if (this.runner.NotifyError) {

     this.runner.NotifyError(this.name, error);

   }

   if (this.runner.NotifyStep) {

     this.runner.NotifyStep(this.name);

   }

 }

 // Runs a single benchmark for at least a second and computes the

 // average time it takes to run a single iteration.

 BenchmarkSuite.prototype.RunSingleBenchmark = function(benchmark) {

   var elapsed = 0;

   var start = new Date();

   for (var n = 0; elapsed < 1000; n++) {

     benchmark.run();

     elapsed = new Date() - start;

   }

   var usec = (elapsed * 1000) / n;

   this.NotifyStep(new BenchmarkResult(benchmark, usec));

 }

 // This function starts running a suite, but stops between each

 // individual benchmark in the suite and returns a continuation

 // function which can be invoked to run the next benchmark. Once the

 // last benchmark has been executed, null is returned.

 BenchmarkSuite.prototype.RunStep = function(runner) {

   this.results = [];

   this.runner = runner;

   var length = this.benchmarks.length;

   var index = 0;

   var suite = this;

   // Run the setup, the actual benchmark, and the tear down in three

   // separate steps to allow the framework to yield between any of the

   // steps.

   function RunNextSetup() {

     if (index < length) {

       try {

         suite.benchmarks[index].Setup();

       } catch (e) {

         suite.NotifyError(e);

         return null;

       }

       return RunNextBenchmark;

     }

     suite.NotifyResult();

     return null;

   }

   function RunNextBenchmark() {

     try {

       suite.RunSingleBenchmark(suite.benchmarks[index]);

     } catch (e) {

       suite.NotifyError(e);

       return null;

     }

     return RunNextTearDown;

   }

   function RunNextTearDown() {

     try {

       suite.benchmarks[index++].TearDown();

     } catch (e) {

       suite.NotifyError(e);

       return null;

     }

     return RunNextSetup;

   }

   // Start out running the setup.

   return RunNextSetup();

 }