Loop Benchmarks: V8 vs RHINO

README.md

Loop Benchmarks: V8 vs RHINO

Looping code was written to be compatible with both engines. It simply does nested loops with multiplication in the body.

• Conclusion: V8 is way faster.
• Caveat: This does not paint a complete picture.

Results:

RHINO

for loop took 1.616 seconds
for loop (optimised) took 1.678 seconds
.forEach loop took 1.451 seconds
.map loop took 3.345 seconds

V8

for loop took 0.004 seconds
for loop (optimised) took 0.002 seconds
.forEach loop took 0.017 seconds
.map loop took 0.031 seconds

loopbenchmarkV8vsRHINO.js

var ITERSTEPS = 1000;
Logger.log("V8");

function runBenchmarks() {
  
  var enter = function () {
    this.array = [];
    for (var k = 0; k < ITERSTEPS; k++) {
      this.array.push(k);
    }
    this.start = new Date().getTime();
  };
  var exit = function (testName) {
    this.end = new Date().getTime();
    var duration = (this.end - this.start) / 1000;
    Logger.log(testName + ' took ' + duration + ' seconds');
  };
  
  var forLoop = function () {
    for (var i = 0; i < this.array.length; i++) {
      for (var j = i; j > 0; j--) {
        i * j;
      }
    }
  };

  var forLoopOptimized = function () {
    var length = this.array.length;  // optimized
    for (var i = 0; i < length; i++) {
      for (var j = i; j > 0; j--) {
        i * j;
      }
    }
  };
  
  var forEachLoop = function () {
    var length = this.array.length;
    var arr = this.array;
    arr.forEach(function (i) {
      arr.slice(0, length - i).forEach(function (j) {
        i * j;
      });
    });
  };
  
  var mapLoop = function () {
    var arr = this.array;
    var length = arr.length;
    arr.map(function (i) {
      arr.slice(0, length - 9).map(function (j) {
        i * j;
      });
    });
  }
  
  var funcs = [ [forLoop, 'for loop'], [forLoopOptimized, 'for loop (optimised)'], [forEachLoop, '.forEach loop'], [mapLoop, '.map loop'] ];
  funcs.forEach(function (values) {
    var func = values[0];
    var name = values[1];
    enter.call(func);
    func.call(func);
    exit.call(func, name);
  });
  
}