Benchmark: Negatives - MeasureThat.net

Script Preparation code:

var num = 1;

Tests:

Bitwise
num = ~num + 1;
Negative variable
num = -num;
Multiply by -1
num *= -1;

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Bitwise
Negative variable
Multiply by -1

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 27 days ago):

LLMs can make mistakes. Check important info.

I'd be happy to explain the provided benchmark and its options.

**Benchmark Definition**

The benchmark definition is a JSON object that defines the characteristics of the test. In this case, the benchmark is called "Negatives" with no description. The script preparation code is set to `var num = 1;`, which initializes a variable named `num` with the value 1. There is no HTML preparation code specified.

**Test Cases**

The individual test cases are defined as an array of objects, each containing two properties: "Benchmark Definition" and "Test Name". These test cases evaluate different options for negating a variable:

1. **Bitwise**: `num = ~num + 1;` - This option uses the bitwise NOT operator (~) to invert the bits of the variable `num`, then adds 1 to it.
2. **Negative variable**: `num = -num;` - This option simply negates the value of the variable `num`.
3. **Multiply by -1**: `num *= -1;` - This option multiplies the variable `num` by -1.

**Pros and Cons**

Here's a brief analysis of each option:

* **Bitwise**: This method can be faster than simple negation because it avoids the overhead of arithmetic operations. However, it may not work correctly on all platforms or in certain situations (e.g., when dealing with fractional numbers).
* **Negative variable**: This is the simplest and most intuitive way to negate a variable. It's widely supported and should be fast.
* **Multiply by -1**: While this method also avoids arithmetic operations, multiplying by -1 can lead to overflow issues on 32-bit platforms or for very large values.

**Library Usage**

There doesn't seem to be any library usage in the provided benchmark definition or test cases. However, if a library like `Math.js` was used to implement the bitwise NOT operator (~), it would add some overhead due to the library's initialization and setup process.

**Special JavaScript Features/Syntax**

None of the options mentioned special JavaScript features or syntax that would affect their performance. The focus is on simple arithmetic operations to negate the variable.

**Alternatives**

Some alternative methods to consider for negating a variable might include:

* Using a function like `Math.abs()` and then calling it with the negative argument (`-num`).
* Using a library like `lodash` with its `negate` function.
* Implementing a custom bitwise NOT operator (~) using a different approach, such as using bit manipulation instructions (e.g., `x = x ^ 0xFFFFFFFF;`) on platforms that support them.

Keep in mind that these alternatives might add overhead due to the library's initialization and setup process or other factors.

Latest run results:

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

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/119.0.0.0 Safari/537.36 Edg/119.0.0.0

Browser/OS: Chrome 119 on Windows

View result in a separate tab

Test name	Executions per second
Bitwise	8538716.0 Ops/sec
Negative variable	8378709.5 Ops/sec
Multiply by -1	7203130.5 Ops/sec

Related benchmarks:

Negatives (version: 0)

Comparing performance of: Bitwise vs Negative variable vs Multiply by -1

Created: one year ago by: Guest

Jump to the latest result

Bitwise

Negative variable

Multiply by -1

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 27 days ago):