Benchmark: Fast Sqrt 2234234

Script Preparation code:

var i;
var r;
var v = 2**16;

function test1() {
  for(i=0; i < 1000; ++i) {
    r = 1 / Math.sqrt(v);
  }
}

function test2() {
  for(i=0; i < 1000; ++i) {
    r = Q_rsqrt(v);
  }
}

//Based on the fast inverse square root function
// https://en.wikipedia.org/wiki/Fast_inverse_square_root
// Some original comments preserved for humor value
// Designed to try to mimic the original as closely as possible
function Q_rsqrt(number)
{ 
    var i;
    var x2, y;
    const threehalfs = 1.5;
  
    x2 = number * 0.5;
    y = number;
    //evil floating bit level hacking
    var buf = new ArrayBuffer(4);
    (new Float32Array(buf))[0] = number;
    i =  (new Uint32Array(buf))[0];
    i = (0x5f3759df - (i >> 1)); //What the fuck?
    (new Uint32Array(buf))[0] = i;
    y = (new Float32Array(buf))[0];
    y  = y * ( threehalfs - ( x2 * y * y ) );   // 1st iteration
//  y  = y * ( threehalfs - ( x2 * y * y ) );   // 2nd iteration, this can be removed

    return y;
}

​x
 
var i;var r;var v = 2**16;​function test1() {  for(i=0; i < 1000; ++i) {    r = 1 / Math.sqrt(v);  }}​function test2() {  for(i=0; i < 1000; ++i) {    r = Q_rsqrt(v);  }}​//Based on the fast inverse square root function// https://en.wikipedia.org/wiki/Fast_inverse_square_root// Some original comments preserved for humor value// Designed to try to mimic the original as closely as possiblefunction Q_rsqrt(number){     var i;    var x2, y;    const threehalfs = 1.5;      x2 = number * 0.5;    y = number;    //evil floating bit level hacking    var buf = new ArrayBuffer(4);    (new Float32Array(buf))[0] = number;    i =  (new Uint32Array(buf))[0];    i = (0x5f3759df - (i >> 1)); //What the fuck?    (new Uint32Array(buf))[0] = i;    y = (new Float32Array(buf))[0];    y  = y * ( threehalfs - ( x2 * y * y ) );   // 1st iteration//  y  = y * ( threehalfs - ( x2 * y * y ) );   // 2nd iteration, this can be removed​    return y;}

Tests:

Math.sqrt
test1();
test1();
Quakes fast inverse sqrt.
test2();
test2();

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Experimental features:

Memory measurements supported only in Chrome.
For precise memory measurements Chrome must be launched with --enable-precise-memory-info flag.
More information: Monitoring JavaScript Memory

Test case name	Result
Math.sqrt
Quakes fast inverse sqrt.

Fastest: N/A

Slowest: N/A

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/100.0.4896.88 Safari/537.36

Browser/OS: Chrome 100 on Windows

View result in a separate tab

Test name	Executions per second
Math.sqrt	6873.2 Ops/sec
Quakes fast inverse sqrt.	1472.3 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):

Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.

Benchmark Definition

The provided JSON represents a benchmark definition for a JavaScript function called Fast Sqrt 2234234. This function is designed to compare two implementations of fast inverse square root calculations, specifically:

The built-in Math.sqrt method.
A custom implementation named "Quakes fast inverse sqrt." (also referred to as Q_rsqrt).

The benchmark measures the performance difference between these two approaches.

Options Compared

The main options being compared are:

Built-in Math.sqrt: This is the standard JavaScript method for calculating square roots.
Quakes fast inverse sqrt. (Q_rsqrt): A custom implementation of fast inverse square root, which is designed to mimic the original algorithm from Wikipedia.

Pros and Cons

Here's a brief analysis of each approach:

Built-in Math.sqrt:
- Pros:
  - Wide support across browsers and platforms.
  - Easy to use and understand.
- Cons:
  - May not be optimized for performance, leading to slower execution times.
Quakes fast inverse sqrt. (Q_rsqrt):
- Pros:
  - Optimized for performance, potentially reducing execution times.
  - Can provide a more accurate result than the built-in method.
- Cons:
  - Requires manual implementation and understanding of the algorithm.
  - May not be compatible with all browsers or platforms.

Library: Quakes

The Q_rsqrt function is implemented in JavaScript, but it relies on some mathematical tricks and bit-level manipulation. The library used for this implementation is not explicitly stated, but it's likely a custom-built library optimized for performance.

Special JS Feature/Syntax

This benchmark uses some special JavaScript features, such as:

Bit-level manipulation (e.g., 0x5f3759df - (i >> 1)).
Floating-point arithmetic (e.g., (new Float32Array(buf))[0] = number;).

These features are specific to the implementation and may not be widely supported or understood.

Other Alternatives

If you're interested in exploring other approaches, here are a few alternatives:

SSE instructions: Some implementations use SSE (Streaming SIMD Extensions) instructions for optimized performance on x86 architectures.
AVX instructions: Similar to SSE, AVX (Advanced Vector Extensions) instructions can be used for even faster performance on modern CPUs.
Native libraries: You can also consider using native libraries like Eigen or Armadillo for more efficient linear algebra operations.

Keep in mind that implementing these alternatives will require a good understanding of low-level computer science and programming expertise.

I hope this explanation helps you understand the basics of the JavaScript microbenchmark on MeasureThat.net!

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks on MeasureThat.net.

**Benchmark Definition**

The provided JSON represents a benchmark definition for a JavaScript function called `Fast Sqrt 2234234`. This function is designed to compare two implementations of fast inverse square root calculations, specifically:

1. The built-in `Math.sqrt` method.
2. A custom implementation named "Quakes fast inverse sqrt." (also referred to as `Q_rsqrt`).

The benchmark measures the performance difference between these two approaches.

**Options Compared**

The main options being compared are:

* **Built-in Math.sqrt**: This is the standard JavaScript method for calculating square roots.
* **Quakes fast inverse sqrt. (Q_rsqrt)**: A custom implementation of fast inverse square root, which is designed to mimic the original algorithm from Wikipedia.

**Pros and Cons**

Here's a brief analysis of each approach:

1. **Built-in Math.sqrt**:
	* Pros:
		+ Wide support across browsers and platforms.
		+ Easy to use and understand.
	* Cons:
		+ May not be optimized for performance, leading to slower execution times.
2. **Quakes fast inverse sqrt. (Q_rsqrt)**:
	* Pros:
		+ Optimized for performance, potentially reducing execution times.
		+ Can provide a more accurate result than the built-in method.
	* Cons:
		+ Requires manual implementation and understanding of the algorithm.
		+ May not be compatible with all browsers or platforms.

**Library: Quakes**

The `Q_rsqrt` function is implemented in JavaScript, but it relies on some mathematical tricks and bit-level manipulation. The library used for this implementation is not explicitly stated, but it's likely a custom-built library optimized for performance.

**Special JS Feature/Syntax**

This benchmark uses some special JavaScript features, such as:

* Bit-level manipulation (e.g., `0x5f3759df - (i >> 1)`).
* Floating-point arithmetic (e.g., `(new Float32Array(buf))[0] = number;`).

These features are specific to the implementation and may not be widely supported or understood.

**Other Alternatives**

If you're interested in exploring other approaches, here are a few alternatives:

* **SSE instructions**: Some implementations use SSE (Streaming SIMD Extensions) instructions for optimized performance on x86 architectures.
* **AVX instructions**: Similar to SSE, AVX (Advanced Vector Extensions) instructions can be used for even faster performance on modern CPUs.
* **Native libraries**: You can also consider using native libraries like Eigen or Armadillo for more efficient linear algebra operations.

Keep in mind that implementing these alternatives will require a good understanding of low-level computer science and programming expertise.

I hope this explanation helps you understand the basics of the JavaScript microbenchmark on MeasureThat.net!

Related benchmarks:

Fast Sqrt 2234234 (version: 0)

Compare Quakes fast inverse squareroot

Comparing performance of: Math.sqrt vs Quakes fast inverse sqrt.

Created: 4 years ago by: Guest

Jump to the latest result

Math.sqrt

Quakes fast inverse sqrt.

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 6 months ago):