Benchmark: Half loop and double iteration ops

Script Preparation code:

var str = 'd sd a SDAS dad sad asd ad SAd sad fgh gfhgjhg fgdjf h;dsfgs dflgk sdljl dfgjdfg lkdfsjgl sdg jdsflg gjdhdjrebfkjsfgnfsd ngkjdfgn dfsng ndfklgndsfkjlgn kjlsdfng jklndfsgljkndsfklgndsfkjlgnfdkjgn sjkflgndfskjlgn dkjlfgnldskjngfdlkjgndsflgn dfskljg nfdgl kdfnsgljkfsdnglkjsdfnglskjdgnsdlfgnsdfjgnsfdlkhj sfdjhl';

Tests:

Loop with N/2 iterations and 2x iteration size
var end = str.length / 2 | 0; var res1 = ''; var res2 = ''; var resA = ''; for (let i = 0; i < end; i++) { res1 += '#' + str[i]; res2 += '#' + str[i + end]; } resA = res1 + res2 + ((str.length % 2) ? '#' + str[str.length-1] : '' ) + '#';
Simple Loop
var length = str.length; var resB = ''; for (let i = 0; i < length; i++) { resB += '#' + str[i]; } resB += '#';
Reverse While
var i = str.length; var resC = ''; while (i--) { resC = str[i] + '#' + resC; } resC = '#' + resC;
Reverse While !== 0
var i = str.length; var resD = ''; while (i-- !== 0) { resD = str[i] + '#' + resD; } resD = '#' + resD;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Loop with N/2 iterations and 2x iteration size
Simple Loop
Reverse While
Reverse While !== 0

Fastest: N/A

Slowest: N/A

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

LLMs can make mistakes. Check important info.

Let's dive into explaining the JavaScript microbenchmark provided by MeasureThat.net.

**Benchmark Overview**

The benchmark consists of four test cases that measure the performance of different loop constructs in JavaScript: Simple Loop, Reverse While, and two versions of Loop with N/2 iterations. The goal is to determine which loop construct is the most efficient.

**Loop Constructs Compared**

1. **Simple Loop**: A traditional `for` loop with a fixed iteration size.
	* Pros: Easy to understand, widely supported, and well-established in JavaScript.
	* Cons: May not be optimized for performance, as it involves array indexing and incrementing the loop counter.
2. **Reverse While**: A `while` loop that decrements the loop counter until reaching 0.
	* Pros: Can avoid array indexing and decrementing the loop counter, which might improve performance.
	* Cons: May not be supported by all browsers or have the same performance characteristics as traditional loops.
3. **Loop with N/2 iterations**: A `for` loop with an iteration size that is half the length of the input string.
	* Pros: Reduces the number of iterations, potentially improving performance by reducing overhead.
	* Cons: May not be supported by all browsers or have the same performance characteristics as traditional loops.

**Library Used**

None explicitly mentioned in the provided benchmark definitions. However, it's likely that the test framework used by MeasureThat.net is utilizing the built-in JavaScript features to execute these benchmarks.

**Special JS Features/Syntax**

The benchmark uses a bitwise OR operator (`|`) to perform integer division and round down to the nearest whole number.

**Other Considerations**

* **Array indexing**: The `for` loop with N/2 iterations involves array indexing, which can be slower than simple string iteration.
* **Loop counter management**: Reverse While loops may require more careful management of the loop counter due to the decrementing nature, which could impact performance.
* **Browser support**: Different browsers might have varying levels of support for these loop constructs or optimize them differently.

**Alternatives**

If you're interested in exploring alternative JavaScript execution engines or optimizing your own benchmarks, some options include:

1. V8 (Node.js Engine)
2. SpiderMonkey (Firefox Engine)
3. WebKit (Safari/Chrome Engines)
4. Baseline.js (a simple benchmarking framework for JavaScript)

When creating your own benchmarks, consider factors like:

* Using a consistent test environment
* Controlling loop iteration size and increments
* Avoiding unnecessary computations or array indexing
* Opting for clear, readable code

Keep in mind that benchmarking is an iterative process, and the best approach might vary depending on specific use cases, hardware, and software environments.

Latest run results:

Run details: (Test run date: 2 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/15.3 Safari/605.1.15

Browser/OS: Safari 15 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Loop with N/2 iterations and 2x iteration size	39077.5 Ops/sec
Simple Loop	40851.2 Ops/sec
Reverse While	40919.0 Ops/sec
Reverse While !== 0	41218.1 Ops/sec

Related benchmarks:

Half loop and double iteration ops (version: 0)

Comparing performance of: Loop with N/2 iterations and 2x iteration size vs Simple Loop vs Reverse While vs Reverse While !== 0

Created: 2 years ago by: Registered User

Jump to the latest result

Loop with N/2 iterations and 2x iteration size

Simple Loop

Reverse While

Reverse While !== 0

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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