Benchmark: test ABS 6 - MeasureThat.net

Script Preparation code:

var abs = Math.abs
var x = -0.00034254146579137945;
var cycle_counter = 1000000;

Tests:

Math.abs
for(i=0; i<cycle_counter; i++){ var result = Math.abs(x); }
abs
for(i=0; i<cycle_counter; i++){ var result = abs(x); }
Custom1
for(i=0; i<cycle_counter; i++){ var negative = x < 0.0 ? 1 : 0; var result = x - x * 2.0 * negative; }
Compare
for(i=0; i<cycle_counter; i++){ var result = x < 0 ? -x : x }
Compare2
for(i=0; i<cycle_counter; i++){ var result = x < 0 ? x * -1 : x }

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Math.abs
abs
Custom1
Compare
Compare2

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (X11; Linux x86_64; rv:133.0) Gecko/20100101 Firefox/133.0

Browser/OS: Firefox 133 on Linux

View result in a separate tab

Test name	Executions per second
Math.abs	671.6 Ops/sec
abs	671.5 Ops/sec
Custom1	669.8 Ops/sec
Compare	669.1 Ops/sec
Compare2	740.2 Ops/sec

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

LLMs can make mistakes. Check important info.

Taking a deep breath, let's dive into the explanation.

**Benchmark Overview**

MeasureThat.net is a website that allows users to create and run JavaScript microbenchmarks. The benchmark you provided involves comparing different approaches to calculate the absolute value of a negative number. The test consists of four individual test cases:

1. `Math.abs`
2. `abs` (a custom function defined in the script preparation code)
3. `Custom1` (another custom implementation)
4. `Compare` and `Compare2` (two different approaches using conditional statements)

**Test Cases**

Let's break down each test case:

### 1. `Math.abs`

This test case uses the built-in `Math.abs` function to calculate the absolute value of a negative number.

**Pros:**

* Easy to implement
* Well-maintained and optimized by Mozilla

**Cons:**

* May not be the fastest due to its overhead

### 2. `abs`

This test case uses a custom function defined in the script preparation code:
```javascript
var abs = Math.abs;
```
The custom `abs` function is essentially an alias for the built-in `Math.abs` function.

**Pros:**

* No additional overhead compared to `Math.abs`
* Faster than using `Math.abs` directly

**Cons:**

* Requires defining a new variable, which may incur some overhead
* May not be as maintainable as using the built-in function

### 3. `Custom1`

This test case uses a custom implementation:
```javascript
var negative = x < 0.0 ? 1 : 0;
var result = x - x * 2.0 * negative;
```
The custom implementation takes advantage of the fact that `-x` is equivalent to `-(x)`.

**Pros:**

* Can be optimized for specific use cases
* May be faster than using `Math.abs`

**Cons:**

* Requires manual calculation and optimization, which can lead to errors or performance issues if not done correctly

### 4. `Compare` and `Compare2`

These test cases use conditional statements to determine the sign of the input value and then calculate the absolute value accordingly.

**Pros:**

* Easy to understand and implement
* May be faster than using a custom implementation

**Cons:**

* May have performance overhead due to the number of branches
* Less maintainable than using a built-in function or custom implementation

**Library**

The `Math.abs` function is part of the JavaScript Math library. The purpose of this library is to provide mathematical functions and constants for use in JavaScript applications.

**Special JS Feature/Syntax**

None mentioned in this benchmark. However, it's worth noting that MeasureThat.net also tests other features and syntax, such as loops, conditional statements, and function calls.

**Alternatives**

If you wanted to rewrite the `Math.abs` function or any of the custom implementations using different approaches, here are some alternatives:

* Using bitwise operations: Instead of calculating `-x`, you can use bitwise NOT (`~`) to get the two's complement representation of the negative number.
* Using a lookup table: You can precalculate the absolute values for common inputs and store them in a lookup table. This approach can be faster for specific use cases but may have overhead due to memory access.
* Using SIMD instructions (if supported by your browser): Some browsers support SIMD (Single Instruction, Multiple Data) instructions, which allow you to perform operations on multiple values simultaneously. You can use these instructions to calculate the absolute value of multiple inputs in parallel.

Keep in mind that each approach has its pros and cons, and the best choice depends on the specific requirements and constraints of your project.

Related benchmarks:

test ABS 6 (version: 0)

Comparing performance of: Math.abs vs abs vs Custom1 vs Compare vs Compare2

Created: 3 years ago by: Guest

Jump to the latest result

Math.abs

abs

Custom1

Compare

Compare2

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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