Benchmark: legacy vs ir-2 - MeasureThat.net

Script Preparation code:

function isJsArray(obj_0) {
    var tmp0_unsafeCast_0 = Array.isArray(obj_0);
    return tmp0_unsafeCast_0;
  }

function isArray(obj_0) {
    var tmp;
    if (isJsArray(obj_0)) {
      tmp = !obj_0.$type$;
    } else {
      tmp = false;
    }
    return tmp;
  }

function arrayConcat(args) {
    var len = args.length;
    var tmp0_unsafeCast_0 = Array(len);
    var typed = tmp0_unsafeCast_0;
    var inductionVariable = 0;
    var last = len - 1 | 0;
    if (inductionVariable <= last)
      do {
        var i = inductionVariable;
        inductionVariable = inductionVariable + 1 | 0;
        var arr = args[i];
        if (!(!(arr == null) ? isArray(arr) : false)) {
          typed[i] = [].slice.call(arr);
        } else {
          {
            typed[i] = arr;
          }
        }
      }
       while (!(i === last));
    return [].concat.apply([], typed);
  }

var args = (new Int32Array(10000)).map(_ => Math.random(1000000));

Tests:

legacy
arrayConcat([0, 1], args)
ir
[].concat.apply([], [[0, 1], args]);

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
legacy
ir

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.16; rv:86.0) Gecko/20100101 Firefox/86.0

Browser/OS: Firefox 86 on Mac OS X 10.16

View result in a separate tab

Test name	Executions per second
legacy	1963127.6 Ops/sec
ir	7091520.0 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated 2 months ago):

LLMs can make mistakes. Check important info.

**Benchmark Overview**

The provided benchmark measures the performance of two different approaches for concatenating arrays in JavaScript: `arrayConcat` (Legacy) and `[] .concat.apply([], [[0, 1], args])` (IR).

**Options Compared**

Two options are compared:

1. **Legacy**: The original implementation of array concatenation using a custom function `arrayConcat`.
2. **IR**: A more efficient implementation using the `concat` method with `apply`.

**Pros and Cons of Each Approach**

### Legacy (`arrayConcat`)

Pros:

* More intuitive and familiar to developers.
* May be easier to understand for those without extensive knowledge of modern JavaScript optimizations.

Cons:

* Less efficient than the IR approach, resulting in slower performance.
* Uses more memory due to the creation of a new array.

### IR (`[] .concat.apply([], [[0, 1], args])`)

Pros:

* More efficient and faster execution time.
* Uses less memory since it only creates a single array with multiple elements.

Cons:

* Less intuitive and may require additional knowledge of modern JavaScript optimizations to understand.

**Library Used**

In the provided benchmark code, no external libraries are used. However, the `Array` class is part of the ECMAScript standard, which means that any modern JavaScript engine will have an implementation of this class.

**Special JS Feature or Syntax**

The benchmark uses a feature introduced in ECMAScript 2015 (ES6) called "template literals" (`_ => Math.random(1000000)`), but it is not essential to the understanding of the benchmark. It's used to generate random numbers for testing purposes.

**Benchmark Preparation Code Explanation**

The `arrayConcat` function takes an array of arguments (`args`) and creates a new array by iterating over each element in the original arrays. If the element is an array, it converts it to an array using `slice.call`. The resulting array is then concatenated with `[] .concat.apply([], typed)`.

**Other Alternatives**

If you were to implement this benchmark yourself, some alternative approaches could be:

* Using the spread operator (`[...[[0, 1], args]]`) which was introduced in ECMAScript 2015.
* Utilizing the `Flat()` method and `Map` objects, which provide more efficient ways of concatenating arrays.

However, these alternatives may not provide significant performance benefits over the existing IR approach.

Related benchmarks:

legacy vs ir-2 (version: 0)

Comparing performance of: legacy vs ir

Created: 3 years ago by: Guest

Jump to the latest result

legacy

ir

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 2 months ago):