Benchmark: 1/x vs x**-1 - MeasureThat.net

HTML Preparation code:

<!--your preparation HTML code goes here-->

Script Preparation code:

let num = Math.random()

Tests:

1/x
num = 1/num
x ** -1
num **= -1

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
1/x
x ** -1

Fastest: N/A

Slowest: N/A

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/133.0.0.0 Safari/537.36

Browser/OS: Chrome 133 on Windows

View result in a separate tab

Test name	Executions per second
1/x	3456569.0 Ops/sec
x ** -1	2773956.0 Ops/sec

Autogenerated LLM Summary (model gpt-4o-mini, generated one year ago):

LLMs can make mistakes. Check important info.

The provided benchmark evaluates two different methods of calculating the inverse of a number, `1/x` and `x ** -1`, using JavaScript. The benchmark is structured with preparation code that initializes a variable `num` with a random value, allowing for consistent testing conditions across the different methods.

### Options Compared

1. **1/x**:
   - **Benchmark Definition**: `num = 1/num`
   - **Test Name**: `1/x`
   - This method calculates the inverse of `num` using the division operator.

2. **x ** -1**:
   - **Benchmark Definition**: `num **= -1`
   - **Test Name**: `x ** -1`
   - This method utilizes the exponentiation operator to achieve the same result by raising `num` to the power of `-1`.

### Performance Results

In the benchmark results, we have two test cases executed on a Chrome browser on a Linux desktop:

- For `1/x`, the execution rate was **15,741,732 executions per second**.
- For `x ** -1`, the execution rate was **11,319,481 executions per second**.

### Pros/Cons of Approaches

#### 1. Division (`1/x`)

- **Pros**:
  - Intuitive: Visually straight-forward and easy to understand.
  - Generally optimized for performance in most engines.
  
- **Cons**:
  - Depending on the complexity of the expression or additional operations, it may have limitations in terms of optimization as compared to exponentiation for certain cases.

#### 2. Exponentiation (`x ** -1`)

- **Pros**:
  - Offers a uniform approach to implementing various power-based calculations.
  - Can be more advantageous when combined with expressions that already involve exponentiation.

- **Cons**:
  - May have a slight overhead compared to direct division due to the additional parsing and computation involved in exponentiation.
  - Less intuitive for simple calculations compared to the direct division.

### Other Considerations

- **Readability**: From a code readability perspective, the division operator is likely more clear to someone reading the code, while exponentiation may seem over-complicated for a simple inversion.
  
- **Performance**: In most JavaScript engines, the division operation is highly optimized and may yield better performance, as indicated by the benchmark results.
  
### Alternatives

Although the benchmark specifically contrasts two methods for achieving the same outcome, other alternatives for computing the reciprocal of a number in JavaScript could include:

1. **Math Functions**: Using functions from the `Math` library, though none exist specifically for reciprocals. For example, `Math.exp(Math.log(num) * -1)` would yield the same result but would be unnecessarily complicated.

2. **Custom Functions**: Implementing a custom function that may add additional checks or context, though at the cost of performance because of function calls.

3. **Handling of Special Cases**: If developing for scenarios involving special fixed-point numbers or types (like BigInts), additional libraries or careful handling would be required.

This benchmark serves to illustrate performance differences in basic arithmetic operations in JavaScript, highlighting that even small syntactical choices can have implications in performance-sensitive applications.

Related benchmarks:

1/x vs x**-1 (version: 1)

Comparing performance of: 1/x vs x ** -1

Created: one year ago by: Guest

Jump to the latest result

1/x

x ** -1

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model gpt-4o-mini, generated one year ago):